upper basin pallid sturgeon recovery workgroup annual

UpperBasinPallidSturgeonRecoveryWorkgroupAnnualReportfor

WorkCompletedin2017

TABLEOFCONTENTS

Introduction…………………………………………………………………………………………………………………………………………….1

AnnualGoverningBoardmeetingminutes-August16-17,2017................................................................2

AnnualWorkgroupmeetingagenda–March8-9,2017............................................................................10

AnnualWorkgroupmeetingminutes–March8-9,2017...........................................................................11

UpperBasinWorkgroup2017SummaryRPMA1......................................................................................20

PallidSturgeonPopulationAssessmentandAssociatedFishCommunityMonitoringfortheMissouriRiver:Segment2.........................................................................................................................................34

2017MissouriRiverSamplingfromtheYellowstoneConfluencetoLakeSakakawea…………………………….37

LowerYellowstoneRiverPallidSturgeonProgressReport.........................................................................39

PallidSturgeonPopulationAssessmentandAssociatedFishCommunityMonitoringfortheMissouriRiver:Segments5and6.............................................................................................................................52

Migrations,Aggregations,andSpawningofPallidSturgeonintheYellowstoneRiverduring2017……..…54

Effectofwatervelocityongrowth,survival,andenergyreservesofendogenousPallidSturgeonScaphirhynchusalbuslarvae…...………………………………..…………………………………………………………………………..75

GenotypicAnalysesandParentalIdentificationsofJuvenileandSub-adultPallidSturgeonintheMissouriRiver……………………………………………………………………………………………………………………………………..……………….79

ExaminationofPallidSturgeon(Scaphirhynchusalbus)LarvalDrift,Development,andSwimmingAbilities……………………………………………………………………………………………………………………….….………………..…..91

GeneticIdentificationofLarvalSturgeonfrom2016UpperMissouriRiverLarvalDriftStudy-FinalReportDecember12,2017……………………………………………………………………………………………………………………………..134

OtherSIUCUpperBasinProjects……………………………………………………….……………….………………………......….142

DeterminationofReproductiveIndicesinHatchery-originPallidSturgeonintheMissouriandYellowstoneRivers…………….……………………………………………………………..……..………….………….…………….…….143

2017PallidSturgeonPropagationActivitiesforGavinsPointNFH...................................................…….146

Introduction

ThisreportdocumentstheworkoftheUpperMissouriRiverBasinPallidSturgeonRecoveryWorkgroup(Workgroup)during2017.ThereportconsistsofminutesoftheannualsummermeetingoftheWorkgroupGoverningBoard,minutesoftheannualWorkgroupmeetingheldinBozeman,MontanainMarch2016,updatesofon-goingworkandreportscompletedbymembersoftheWorkgroupandothercontractors.

TheGoverningBoardoftheWorkgroupduringthisperiodconsistedofthefollowingindividuals.Theirworkaffiliationandthefocusareastheyrepresentareindicated.

ZachShattuck,Chair,MontanaFish,WildlifeandParks

AnneTews,MontanaFish,WildlifeandParks,RPMA1

MatRugg,MontanaFish,WildlifeandParks,RPMA2

LandonPierce,U.S.FishandWildlifeService,RPMA3

TylerHaddix,MontanaFish,WildlifeandParks,Habitat

PatBratten,U.S.GeologicalServices,Research

RobHolm,U.S.FishandWildlifeService,Propagation

KenStaigmiller,MontanaFish,WildlifeandParks,FishHealth

KevinKappenman,U.S.FishandWildlifeService,StockingandTagging

RyanWilson,U.S,FishandWildlifeService

MeetingNotesfromthe

UBPSWGGoverningMeeting

August16-17,2017

Billings,MT

ThefollowingarethenotesfromtheAugust2017meetingoftheUpperBasinPallidSturgeonRecoveryWorkgroupGoverningBoard.Afewofthediscussionsaregroupedoutoftheorderinwhichtheyoccurredduringthetwo-daymeetingforclarityandtocombinemultiplediscussionsofsingletopics.Asummaryoftheactionitemsassignedduringthemeetingappearsattheendofthemeetingnotes.RyanWilson,TylerHaddix,AnneTews,ZachShattuck,MatRugg,KenStaigmiller,PatBraaten,RobHolm,LandonPierce,BobSnyder,KevinKappenman,LarryGamble,DavidTrimpe,ChristinaGomer,andLouHaneburywerepresentatthemeeting.AttendingbyphonewasBrianMarotz.OpeningCommentsMattMarsh,withWAPA,gavetheopeningremarks.WAPAprovides$300,000annuallytofundUpperbasinprojects.Ifaspecialprojectrequiresadditionalfunding,theremaybeadditionalfundingavailable.MattencouragedcommunicationwithDonSkaar,theMontanarepresentativeonMRRIC,tobringuptopicsandconcernswiththeUSACE.Therewillbeanewregionaldirectorappointedduringthenextfewmonths.

AI–ZachwillsetupameetandgreetconferencecallwiththenewWAPAregionaldirector.LouisretiringattheendofDecember2017.ChristinaGomerwillbetheWAPANEPACoordinatorandtheWorkgroup’scontactwithinWAPA.Duringdrought,WAPAhastoborrowmoneyduetolowflowsandreducedpowergeneration.WAPAisamemberoftheSouthwestPowerPool.RecoveryTeamupdate-GambleWyattDoylefinishedhistenureasRecoveryTeamLeaderasofJuly.LarrypresentedhisideasforreplacingthevacantRecoveryTeamLeaderposition.TheUSFWSisconsideringtwooptionsforanewRecoveryTeamleader.

Shortterm(1yearormore?)–HaveeitherLandonPiercesolely,orLandonandWayneNelson-Stastnyjointlyoccupytheposition.ThiscouldoccurbeforetheendofAugust.AI-LarrysuggeststhattherebeaconferencecallwithLandon,WayneandtheUpperBasinWorkgroupaftertheRTLdecisionismade.

Longterm–Thedesirableendgoalistoidentifyapermanentcandidateusingthe“GeorgeJordanmodel”wheretheRecoveryTeamLeaderisalsothePallidSturgeoncoordinator.Thisprocessmaytakemorethanayeartocompletebecauseofbudgetissuesandahiringfreeze.

TherewillprobablybeaRecoveryTeammeetingoncethetransitiondecisionismade.

MiddleBasinupdateThebroodstockcollectioncapturedfewerPallidSturgeonthaninpastyears.Theconditionofthecapturedfishwasslightlybetterthanlastyear.Wasmortalityofadultsthecauseoftheincreasedcondition?IntakeDiversionupdate-TrimpeWorkatIntakehasceasedbecauseoftheJuly5injunction.Thereshouldbeahearingbysummer2018.Theprocessforthefinalsummaryjudgmentisexpectedtobea1½-2yearprocess.Thecontractwiththecontractorhasbeenterminated.NoreenWalsh(USFWS)statedthatIntakewillnolongerbeintheUSACE’sbaselinefortheUpperMissouriRiver.Thiswasunexpected.BuRecwillevaluatethePallidSturgeontranslocationprojectatIntakethisfall.BuRecprobablygoingtocontinuerockingexistingweirtoprovidewatertoirrigators.EffectsAnalysis-GambleTheEAteamisworkingonanewmonitoringprogramandisworkingthroughthecommentsontheDEIS.TheUSFWSwillmeetwithRobJacobsonandJoeBonneaunextweek.USFWSwillstresstheneedformoreface-to-faceinteractions,ratherthanrelyingsolelyonaone-wayblogforcommunication.TheUSFWSwantsmorediscussionandinteractivediscussions,ratherthanjustreviewingdraftdocuments.TheEISiscurrentlyscheduledforcompletionsometimeduringthesummerof2018.TheRecordofDecisionshouldbeoutbythefallof2018.FWPupdate–ShattuckFWPPallidSturgeonbiologistsandmanagersfromregions4,6,and7metwiththenewFWPDirectorMarthaWilliamsandAssociateDirectorPaulSihler.FWPwillworktoimprovecommunicationwiththeUSFWS.Workgroupoperatingprocedures–ShattuckZachpresentededitstotheexistingoperationproceduresdocument.HewillsendadraftouttoGoverningBoardmembersfortheirreview.

AI-CommentsondraftchangestooperationalproceduresdocumentshouldbesenttoZachbySeptember8,2017.

WorkgroupMemorandumofUnderstanding–ShattuckThecurrent(2008)MOUwillexpireinJuly2018.LoustatedthathavingcontractorssigntheMOUsimplifiesWAPAcontractingpractices,asindividualcontractingnegationswouldnotberequired.AsimplereferencetotheMOUwouldsuffice.

AI–ZachwillworkwithLandonandLoutogettheupdatedWorkgroupMOUapprovedandsigned.

FacilitatorMOU–ShattuckThisMOUneedsrenewal.

AI–ZachwilldraftanupdatedfacilitatorMOU.RPMA1update–TewsAnnegaveaPowerPointpresentationaboutthenewPITtagsystemthatwasexperimentallyusedinRPMA1.Thissystemusesthenewstandardfrequency(134.2kHz)fortagginganimals.Ituseseither12.5mmor23.5mmPITtags.ThenewPITtagsareinsertedintheabdomenoffishusinganincision.The125kHztagscurrentlyusedareobsolete.Thenewtagsarecheaper($1.70vs.$3.10).Thecurrentinventoryof125kHztagscanbeexchangedfornewtags.AnnesuggeststhenewsystemandstandardbeadoptedintheUpperBasin.Thecurrenttaggingprotocolencouragesadoptingthenewstandard,butdoesnotindicatehoworwhenitshouldbedone.GuidanceastohowtoproceedtoupdatetheTaggingandsamplingProtocoltoadoptthenewsystemwillberequestedfromtheRecoveryTeam.

AI-Kevinwillleadtheefforttoupdatethetaggingandsamplingprotocoltoconvertfrom125Khzto134.2kHzsystems.

Thefirststepwillbetoacquireandemploydualfrequencyreaders.WAPAfundingcanbeusedforthis.LourequestedthatWAPAreceiveadescriptionofwhatisrequiredtoconverttothenewsystem.

AI-ZachwilldraftandsendalettertotheUSFWSthatincludesadetailedproposaltoconverttothenew134.2kHzsystem,includingtheprosandconsandhowthetransitioncouldoccur,andrequestingrecoveryteamandUSFWSapprovaltobeginimplementationofthenewsystem.

AI-ZachandKevinwillcoordinatethetransitiontothenewPITtagsystem.

RPMA2update–WilsonLackofgrowthofstockedPallidSturgeonisaconcern.Therearefew’07and’08ageclassesthataregreaterthan500mm.Hatchery-stockedPallidSturgeonhavebeennettedinLakeSakakawea.Highflowsmadecapturingadultbroodstockdifficult,butninefishweresenttoGPNFH.

TheDepartmentofJusticehasfundingforcontaminantssampling.Tyler,Mat,RyanandtheircrewswillattendsamplingtrainingandperformsamplinginitiatedbecauseoftheoilspillsintheYellowstoneRiver.MilkRiver/MissouriRiverupdate–HaddixTheMilkhadlowflowsin2017,soTylerdidn’tseemanyPallidSturgeonusetheMilk.Fewlarvaeweresampledaswellasjuveniles.PallidSturgeonthatstaybelowFortPeckDamarethinanddon’tgrow,probablyduetolowtemperaturesandpoorproduction.Yellowstoneupdate–RuggPaddlefishhavebeenfoundintheBigHornRiverduetoextendedhighflows.ThePallidSturgeontranslocationprojectcaptured,taggedandmovedfivePallidSturgeonfrombelowIntakeDam.AnyPallidSturgeoncaughtbetweenIntakeDamandthemouthofthenaturalsidechannel,weretranslocated.Twowildmalesandonejuvenilemalewerelocatedmorethan100milesupthePowderRiver.ThreePallidSturgeonusedthenaturalsidechanneltobypasstheIntakeDam,butrapidlyreturnedbackdownstream.PallidSturgeonspawningtelemetryupdate–BraatenThreefemalePallidSturgeonweretrackedtonormalspawningareasnearFairview.Freeembryoscapturedbelowthesitesconfirmedthattheyspawned.AdyereleasewasconductedattheGlendiveboatramp.RPMA3update–PierceLownumbersofPallidSturgeonwerecaughtthisyearduetohighflows.RPMA3fisharedisplayinglowgrowthratessimilartowhatisobservedinRPMA2fish,althoughtheyachievelargertotallength.SouthDakotahasceasedpopulationassessmentactivitiesupstreamofSegment7.Landon’sofficemaytakeonthework.220PallidSturgeonhavebeendocumentedtohavemoveddownstreampastdam.MilesCityHatcherypropagationupdate&fishhealth–StaigmillerMCSFHdoesnothavePallidSturgeonthisyear.FWPmusthaveinternaldiscussionaboutMCFHS’sparticipationinthePallidSturgeonprogram.SNSfromWyomingarepositiveforiridovirus.

Driftstudyupdate–BraatenandHaddixEdHeistidentified58PallidSturgeonofthe1269freeembryosamplescollectedduringthedriftstudy.Allbuttwocamefromthefirstnight’ssample.Thetwootherswerefromthesecondnight’ssampling.“Walls”ofsamplingatCulbertsonandWillistondidnotcaptureanyPallidSturgeon.Flowswereapproximately10,000cfsduringtherelease.Whathappened?Edwasalsosent450YOYsturgeonsamplesforidentification.Resultsarepending.GarrisonDamNFHpropagationupdate–HolmGDNFHhadtenfishfromtheconfluenceforspawning.ThereweretwofemalesfrombothRPMA1andRPMA2.Robletsfishrecoverpost-spawnpriortobeingreleased.Robhas227progenyfromthefemalethatdiedthisspring.Allmaleswereincludedinthecryo-repositoryinWarmSprings.Spermusedfromthe2001cryo-preservedmaleshadhighfertility.Spawningmatricesarebeingusedtocreate“boutique”matingstoequalizegeneticrepresentationamongtheUpperBasinRPMAsandtoincreasetheireffectivepopulationsize.Earlylife-stagemortalityisasourceofundesirablenon-randomhatcheryselection.Robisobservingvariableutilizationoffeedamonglots.Robbelievesitmaybeduetoproblemsrelatedtoenzymesinvolvedinfeedutilization.RobwouldlikethePropagationCommitteetorevisitearlylife-stagemortality.

AI–SnyderwillcontactMollyaboutanearlylife-stagemortalityconferencecall.

Thecurrentstockinggoalsforspringyearlingsin2018are:RPMA1 RPMA2 RPMA31500 1500 110RobneedsthenumberstobestockedbyfamilyfromtheRPMAbiologistsbyOctober1sothathecanmanagehisinventory.

AI–RPMAbiologistsneedtogiveRobtheirnumbersoffishstockedbyfamilybyOctober1.SurvivalestimatesJayhasreleasedadraftofthelatestsurvivalestimates.Theestimatedsurvivalsoffall-andspring-stockedPallidSturgeonhavechangedfromearlierestimates.Ryanstatedthatthesurvivalestimatesareunderestimations.Ryanaskedifweneedtoincreasetheeffortoverashortperiodoftimetoimprovethenumbersoffishcapturedandimprovesurvivalestimates.TheGoverningBoarddecidedtoscheduleaconferencecallattheendofSeptemberandameetingattheendofthedayofthecontinuingeducationtrainingworkshopinconjunctionwiththeMarchworkgroupmeetingtodiscusssurvivalestimationwithJay.

AI–ZachwillsetupconferencecallbetweenbiologistsandJay.Afollow-upmeetingwilltakeplaceinconjunctionwiththeWorkgroupmeeting.

StockingplanRotella’ssurvivalestimatesdifferfromthevaluesusedintheoriginalstockingplan.Thepurposeofstockinghaschangedfromdemographicgoals(numbers)tomaximizingeffectivepopulationsize.Thestockingplanneedstobere-written.

AI-Snyderwillcoordinatethere-writeofthestockingplanfortheUpperBasin.HewillinvestigatehowtheRange-wideStockingPlancanbemodulizedtopermiteasierbasin-specificchanges.CommentsandsuggestionswillbesenttotheRecoveryTeamLeaderandLarry.

InvasiveproceduretrainingRobobservedapoorly-healed,twoyearoldincisioninoneofthebroodstockandisconcernedthatthosethatuseinvasivetechniques(transmitterimplantation,sexingandassessmentofreproductivestatus)arenotbeingadequatelytrained.HebelievesthatthesepeopleneedtobefamiliarwiththeanatomyofPallidSturgeontoavoidcausingdamagetointernalorgans.Kevinsaidthatthereisalegal,(i.e.lawenforcement),riskhavinguntrainedpeopleperforminvasiveprocesses.Itwasdecidedthatstudents,techniciansandbiologistswillbegiventraining,asneeded,toreducedamageandmortalityforminvasiveprocesses.KevinsaidtheyhavelotsoffishavailableattheBFTCfortraining.HeiswillingtoleadatrainingworkshopattheBFTC.AnnesuggestedRobmakeavideothatcouldbedownloadedandaccessedinthefield.CanUSFWSpermitsrequiretrainingofpermitholders?

AI-LarryandRyanwillinvestigateamendingpermitlanguagetorequirehandlingtraining.AI-ZachwillinvestigateifitispossibletoamendFWPcollectors’permitstorequiretraining.AI-Kevin,RyanandZachwilldevelopinvasiveproceduresworkshoptrainingrequirements.AI–Kevinwillcoordinateinvasiveprocessestraining.

Itwasagreedthatspringwasthebesttimefortraining.ZachsuggestedthatacontinuingeducationsegmentbeaddedtotheMarchWorkgroupmeeting.TheGBagreed,thereforetheMarchWorkgroupmeetingwillbeheldinBozeman.WAPAFunding–HaneburyThedraftproposalforFY18WAPA-fundedprojectswillbeavailableinDecember.LouencouragedWAPAcontractorstosendininvoicesassoonaspossible.WAPAfundingisusuallyavailableforthreeyearsfromapprovaldate.Overheadrateshaveimpactedanddelayedapprovalandfundingofsomeprojects.

AI–LouwillsendZachWAPA’spolicyontransmitter/receiverpurchasing.

WebsiteimprovementsLouofferedimprovementstothePallidSturgeonwebsite.TheGoverningBoardwouldliketohavealibraryofdocumentspostedonthewebsite,althoughthiswillrequirelimitedaccesstothelibrary.Ataminimum,weshouldmakeavailableabibliographyofPallidSturgeonliteratureincludingrecoveryandconservationdocuments.

AI-Snyderwillworkonthebibliography,libraryandwebsiteaccessissue.

UpperBasinWorkgroupChair–ShattuckZachwasapprovedbytheGoverningBoardtoanothertwo-yeartermasWorkgroupChairperson.FY2018Workplan–ShattuckTheGoverningBoardreviewedanddiscussedtheproposalssubmittedforWAPAfundinginFY18.GoverningBoardmemberswillsendtheirselectionsforapprovaltoZachbytheendoftheweek.TheUpperBasinWorkgroupmeetingwilltakeplaceinBozemanonMarch6-8.Thiswillincludeaninvasiveproceduresworkshop,ameetingwithJayregardingsurvivalestimates,andtheWorkgroupmeeting.

SummaryofActionItems1. ZachwillsetupameetandgreetconferencecallwiththenewWAPAregionaldirector.2. LarrysuggeststhattherebeaconferencecallwithLandon,WayneandtheUpperBasinWorkgroup

aftertheRTLdecisionismade.3. CommentsondraftchangestooperationalproceduresdocumentshouldbesenttoZachbyAugust

31,2017.4. ZachwillworkwithLandonandLoutogettheupdatedWorkgroupMOUapprovedandsigned.5. ZachwillworkwithLandonandLoutogettheupdatedWorkgroupMOUapprovedandsigned.6. ZachwilldraftanupdatedfacilitatorMOU.7. Kevinwillleadtheefforttoupdatethetaggingandsamplingprotocoltoconvertfrom125Khzto

134.2kHzsystems.8. ZachwilldraftandsendalettertotheUSFWSthatincludesadetailedproposaltoconverttothe

new134.2kHzsystem,includingtheprosandconsandhowthetransitioncouldoccur,andrequestingrecoveryteamandUSFWSapprovaltobeginimplementationofthenewsystem.

9. ZachandKevinwillcoordinatethetransitiontothenewPITtagsystem.10. SnyderwillcontactMollyaboutanearlylifestagemortalityconferencecall.11. RPMAbiologistsneedtogiveRobtheirnumbersoffishstockedbyfamilybyOctober1.12. ZachwillsetupconferencecallbetweenbiologistsandJay.Afollow-upmeetingwilltakeplacein

conjunctionwiththeWorkgroupmeeting.13. Snyderwillcoordinatethere-writeofthestockingplanfortheUpperBasin.Hewillinvestigatehow

theRange-wideStockingPlancanbemodulizedtopermiteasierbasin-specificchanges.CommentsandsuggestionswillbesenttotheRecoveryTeamLeaderandLarry.

14. LarryandRyanwillinvestigateamendingpermitlanguagetorequirehandlingtraining.15. ZachwillinvestigateifitispossibletoamendFWPcollectors’permitstorequiretraining.

Upper Basin Pallid Sturgeon Workgroup MeetingMarch 8-9, 2017

Red Lion Hotel and Conference Center1223 Mullowney Ln.Billings, MT 59101

(406) 248-7151https://join.freeconferencecall.com/zshattuck

zshattuck(712) 451-0200

875393

Wednesday (3/8) Time (MST): Topic: Speaker(s):

10 min 0800-0810 Introductions and opening remarks Zach Shattuck, Bob Snyder

10 min 0810-0820 Pallid Sturgeon Recovery Team and MB, LB Workgroup updates Wyatt Doyle

20 min 0820-0840 Pallid Sturgeon telemetry project in RPMA 1 Chris Guy20 min 0840-0900 Missouri River above Ft. Peck Reservoir monitoring and telemetry Anne Tews, Mike Schilz20 min 0900-0920 Hatchery-reared Pallid Sturgeon telemetry in RPMA 2 Landon Holte20 min 0920-0940 Pallid Sturgeon movement and spawning in the Yellowstone River Pat Braaten20 min 0940-1000 Yellowstone River native fish telemetry study Mat Rugg

10 min 1000-1010 Break

20 min 1010-1030 Update on the 2016 Pallid Sturgeon free embryo dispersal experiment Pat Braaten20 min 1030-1050 Update to 3D river-mapping efforts during the 2016 Missouri River drift study Brian Marotz20 min 1050-1110 Update on Carrying Capacity Study in RPMA 2 - fish Addie Dutton20 min 1110-1130 Update on Carrying Capacity Study in RPMA 2 - macroinvertebrates Eric Scholl

120 min 1130-1330 Lunch

30 min 1330-1400 Update on the MRRMP-EIS and BiOp Doug Laye30 min 1400-1430 Upper Missouri River Basin Effects Analysis Robb Jacobson10 min 1430-1440 Missouri River Recovery and Implementation Committee Don Skaar

15 min 1440-1455 Oil-spill response training and baseline monitoring for Pallid Sturgeon David Rouse, Karen Nelson, Don Tillitt15 min 1455-1510 Redwater River fish passage improvement Steve Dalbey

10 min 1510-1520 Break

20 min 1520-1540 Broodstock collection coordination in RPMA 1&2 Group Discussion30 min 1540-1610 Translocation of Pallid Sturgeon at Intake Group Discussion20 min 1610-1630 10-year strategy, furthering recovery, RFP process, outreach opportunities Zach Shattuck, Bob Snyder

Thursday (3/9) Time (MST): Topic: Speaker(s):

20 min 0800-0820 Segments 1-3 (Ft. Peck Dam to Confluence) Landon Holte20 min 0820-0840 Segment 4 (Confluence to headwaters of Lake Sakakawea) Ryan Wilson20 min 0840-0900 Segments 5-6 (Ft. Randall Dam to headwaters of Lewis & Clark Lake) Landon Pierce20 min 0900-0930 Monitoring objectives and protocols for Upper Basin in PSPAP 2.0 Group Discussion

20 min 0930-0950 Wild-caught Pallid Sturgeon genetics monitoring Meredith Bartron, Jeff Kalie10 min 0950-1000 Hatchery-reared and released Pallid Sturgeon reproductive indicies Molly Webb10 min 1000-1010 Gavins Point captive broodstock monitoring Molly Webb

10 min 1010-1020 Break

20 min 1020-1040 Garrison Dam NFH Rob Holm20 min 1040-1100 Gavins Point NFH Chris Hooley20 min 1100-1120 Miles City FH Mike Rhodes, Cory Hagemeister

10 min 1120-1130 U.S. Fish & Wildlife Service Wyatt Doyle10 min 1130-1140 Western Area Power Administration Lou Hanebury10 min 1140-1150 NorthWestern Energy Steve Leathe10 min 1150-1200 U.S. Bureau of Reclamation David Trimpe10 min 1200-1210 U.S. Army Corps of Engineers

20 min 1210-1230 TBA Zach Shattuck, Bob SnyderOther Items, Discussion, & Closing

Movement & Spawning

Larval Drift and Carrying Capacity

Agency Updates

Population Assessment Sampling & Monitoring

Hatchery Updates

Welcome & Housekeeping

Recovery Team & Workgroup Updates

Workgroup Coordination

Genetics & Broodstock

Effects Analysis & Missouri River Recovery Program

Online Meeting Link:Online Meeting ID:

Call-in Number:Participant Code:

2017UpperBasinPallidSturgeonWorkgroupMeeting

March8-9,2017RedLionHotelBillings,MT

WyattDoyleEachWorkgroupneedstoidentifypriorityresearchandmonitoring.Identifythebiggestissueinthebasinandhowwe’dliketotackleit.IdentifyhowtheFWScanincorporateintomanagement.TheLowerBasinWorkgroupidentifiedmicrochemistryandrecruitmentastheirmainissues.TheMiddleBasinidentified“skinnyfish”astheirmainconcern.WyattwillbesteppingdownasRecoveryTeamLeader.ChrisGuy–RPMA1telemetrystudyThenewprojectinRPMA1willstudythereproductiveecologyofhatcheryandwildpallidsturgeon.OneobjectiveistodetermineifwecangetpallidsturgeontospawnfarenoughupstreamofFortPeckReservoirtoallowsufficientdrift.Luke’stelemetryprojectdeterminedthattheearliesthatchery-originpallidsturgeonmalesmaturedis14years.Forfemales,itis18years.Somemalesexhibitedabiennialcycle.Bothhatchery-originandwildreproductivemalesmadesimilarmovements.Non-reproductivemalesdidn’tmovemuch.ThemaximummovementisslightlyupstreamoftheFredRobinsonBridgearea.Ofreproductiveadults,60%ofmaleswereclusteredapproximately50kmofriverbymidtolateMayin2015.In2016,40%wereclusteredin20kmofriver.Forspawning,aminimumwatertemperatureof24ͦ°CisneededabovetheMarias.Allfemaleswentatretic.Furtherresearch:Identifyhabitatcharacteristics;determinewhyfemalesaregoingatretic;anddetermineifmalesarespawningand,ifso,withwhom?The2017projectwillfocusonidentifyinghabitatcharacteristics,determiningthecauseofatresia,investigateifthefemalesaremaking“dummy(conditioning)runs”,anddeterminewhatspawningcuesareneededandifsomearemissing.

AnneTews–SturgeonSamplinginRPMA1Estimatesofshovelnosesturgeonpopulationweremadewithmorethan100netdrifts.Asimilareffortin2009wasrepeatedin2015atFredRobinsonand1995and2008estimateswererepeatedin2016atCoalBanks.Theresultsindicateadeclineinshovelnosesturgeon:

SNSestimatesintwoRPMA1reaches

ShovelnoseSturgeonwentfrom1300permileto670permile.Annesuggeststhisdecreasewasduetolowreproductionduringthedrought.Pallidsturgeoncapturesvariedfrom0to0.25pernet.Theyaveraged2mmperyeargrowth.Oneshovelnosesturgeonwasrecaptured37yearsafteritsoriginalcapture(approximately60yearsold).A2002hatchery-producedSNSwithfincurlsurvived.Thereisagoodopportunityforbroodstockcollectionin2017.LandonHolte–Missouri/MilkHRPStelemetryThereare132telemeteredpallidsturgeoninstudyreach,mostare2002year-class.Four1997age-classhatchery-originpallidsturgeonusedtheMilkRiverin2016duringJuneandJuly.A1997age-classfemalespent1.5monthsintheMilkRiver,butherreproductivestatusisnotknown.NoextantadultsmovedintotheMilkRiver.Sixty-twopaddlefishand16sturgeon(undetermined,geneticsamplessubmitted)werecapturedduringlarvalsampling.A1997femalemovedasfarasIntake.Herreproductivestatusisunknown.In2016,thelargestsampleofYOYsturgeon,withawiderangeofsizeswerecaughttodate.Geneticidentificationispending.Theyareseeingmovementsofspawningfish.Itmaybedesirabletocapturethesefishandidentifytheirreproductivestatus.

Year CoalBanks FredRobinson

1995 8700

2005 8518

2009 2078

2015 2898

2016 4386

MatRugg–YellowstoneRivernativespeciestelemetryThisprojectinvestigateshowthecurrentIntakeDamstructureaffectsfishmovement.Pallidsturgeon(hatchery-originandwild),bluesuckers,sauger,shovelnosesturgeonandpaddlefisharethespeciesinvestigated.OnehalfofyearlingpallidsturgeonintheGlendivereachmovedupstream.NopallidsturgeonatIntakemovedupstream.Inearlytomid-Maypaddlefishmovedto,butnotaboveIntakeandthendisplayedabigmovementtotheMilkRiver.MosttelemeteredSaugerandBlueSuckerwereabletomovepasttheexistingstructure,withmostSaugermovingJunetolate-JulyandBlueSuckermovingmid-Aprilthroughlate-June.ThreeShovelnoseSturgeonmovedupstreamofIntakeatlowerflowsinJuly;perhapsexhibitingsomeinherentdifferencesbetweenShovelnosesandPallids.Also,twoShovelnoseSturgeonthatwerefoundintheYellowstoneRiverwerealsocontactedintheMilkRiverinMay.BraatenwillwriteapproachtotranslocationprojectatIntake.TheUSBRAMPallowsforatranslocationproject.PatBraaten–PallidSturgeonmigrations,aggregationsandspawningintheYSRTherewerenoknownreproductivefemalesforthe2016assixfemaleswerecapturedandusedtoproducefreeembryosforthedriftstudy.Thereweremanyreproductivemales.Manypallids(14%oftelemeteredpopulation)moveduptoIntakeMay5-7andthenmovedbackdowntoaggregateinlower10milesoftheYellowstoneRiver.NotelemeteredfishmovedpastIntakeDamthroughthenaturalsidechannel.Notallfisharemigrators,someare“homebodies”.Threehundredandfifteenfreeembryosandlarvaewerecapturedbelowsuspectedspawningaggregations.Geneticanalysisispending.PatBraaten–DispersalofpallidsturgeonfreeembryosintheMissouriRiverThelarvaldrifthypothesisis:“Underexistingconditions,thereisaninsufficientlengthoffree-flowingriverinehabitatavailablebetweenspawning(hatch)andsettlinglocationsinfragmentedriverreachesforpallidsturgeonfreeembryostocompleteontogeneticdevelopment,transitiontobenthic-orientedlarvae,andsurvive.”Thestateofsciencerelevanttothelarvaldrifthypothesis:

1. Recruitmentfailure/curtailmentpost-57.2. Confirmedspawning.Shortdriftdistance,norecruitmentdetected.3. Confirmedspawning,longdriftdistance,norecruitmentdetected.4. Mortalityofpallidsturgeonearlylifestage(ELS)inriver-reservoirtransitionzones.5. SurvivalofpallidsturgeonELSinheadwatersofLakeSakakawea.6. Fateofslowdrifters,settlement,andsurvivaloffreeembryos.7. Hydraulicdriversoffreeembryodispersal.

a. “Some”survivalpredictedfrommainstemlarvaldriftmodels.b. Nosurvivalpredictedfromhydraulicmodels.

ModelingiscentraltoMissouriRiverEffectsAnalysisandManagementPlan.Objectivesofstudy:

1. Quantifypre-settlementdriftanddispersalattributes.2. Identifysettlinglocationswherepallidsturgeontransitionfromdispersingfreeembryosto

settledbenthiclarvae.3. Identifyandquantifyhydraulicelementsdrivingfreeembryodispersalandlarvalsettlement.4. Testexistingdispersalmodelsanddevelopmorerefineddispersalmodels.

Forthestudy,697,00freeembryos(<2dayspost-hatch)werereleasedintotheMissouriRiverbelowFortPeckDam.Twobeadtypeswithdifferentdensitieswerealsoreleasedtoseeiftheycouldbesurrogatesforfreeembryos.Benthictrawlingwasperformedinstudyreachtodetectsettledlarvae.450Scaphirhynchussp.Settledlarvaewerecaptured(themostcapturedsincetrawlingbeganin2002).Geneticresultsarepending.BrianMarotz–EstimatingthespeedandpathwaysofdriftingpallidsturgeonfreeembryosMorethan200milesoftheMissouriRiverweremapped9milkRivertoWilliston).Channelbedformandhydrauliccomplexitycontrolslarvaldriftspeedandpathways.Fastestdrifter(10%)couldreachLakeSakakaweain6.5daysiftheyremaininthalweg.Ninetypercentaresweptfromthalwegintolowvelocityhabitats,extendingriverresidence.Morethan50%stalledalongriverbanks,islandsandchannel-spanningsanddunes.Thesefishwouldhavetore-suspendtocontinuedrifting.DriftersnearthebottomwouldnotreachLakeSakakaweafor31days,indicatingdriftdurationmaynotbelimitingpallidsturgeonrecruitmentdownstreamofFortPeckDam.DougLaye–BiOpDougistheSection7leadforMRRMPBiOpandwastheprimaryauthoroftheIntakeBiOp.HeishelpingtheUSACEputtogethertheBiologicalAssessmentfortheMPPMP,scheduledtobecompletedbyfallof2017.TheFWShas90daystoconsultand45additionaldaystoproducefinaldecision(BiOp).

PatBraatenandRobbJacobson–EffectsAnalysisTasksfor2017:

1. CompleteMiddleBasinfishconditionreport2. Developrecommendationsforupdateofpallidsturgeonpopulationassessmentprogram.

(March21workshop)3. Development,deploymentandapplicationofcollaborativepopulationmodel.4. SetuptransitiontoTechnicalTeam5. RefinesciencecomponentsasAMplanisrevised.

DonSkaar–MRRICMRRIChas28members.DonistheMontanarepresentative.TherewillbeanimportantmeetinginAugusttoassessallperspectivesandconcernswithinMRRIC.Thereareconcernsinthelowerbasinaboutchangestothecurrentmastermanual.EricScholl–CarryingCapacityProject(macroinvertebratefoodresources)Twoscenariosareconsidered:sturgeonarefeedinginproportiontohabitattypesandsturgeonareonlyobtainingfoodfromsandhabitats.Shovelnosesturgeon-22%oftheirmacroinvertebratedietsnotassociatedwithsand.Pallidsturgeon–46%oftheirmacroinvertebratedietsnotassociatedwithsand.Plansfor2017include:

Completionoflabworkbyspring.Refinemacroinvertebrateproductionestimates.Buildtrophicsupplyanddemandmodelforpallidandshovelnosesturgeonbyearlyfall.

AddieDutton–PallidsturgeonfoodwebLookingatthedietsofpallidandshovelnosesturgeon;emeraldshiner,flatheadchub,sturgeonandsicklefinchubs;goldeyes;stonecatsandchannelcatfish.Thefoodwebisverycomplex.Somespeciesarespecialistsandsomearegeneralists.SteveDalbey–RedwaterRiverFishPassageFishpassageintheRedwaterRiverwasadverselyaffectedbythepoordesign(aseriesofperchedculverts)ofacrossingstructure.Thisimpactedpallidsturgeonbylimitingforagefishproduction.Thisstructurewasreplacedwithadesignthatallowfishpassage.In2015sevenspeciesmovedabovethestructure.Thereisanotherbarrier2milesupstreamthatrequiresreplacement.

DavidRouse–OilspillresponsetrainingandbaselinemonitoringforpallidsturgeonTheobjectivesofthisprojectare:

1. Pallidsturgeonriskassessmentandresponseplandevelopment2. Oilspillpreparednessfishhealthsamplingtrainingandbaselinesampling.

Thefishhealthassessmentwilllookatthepresenceandeffectsfrompolyaromatichydrocarbons(PAHs).LookingtohavesamplingandtraininginearlyJune(orasfieldstaffdictateotherwise).Threesamplesfromthreelocationsofpallidsturgeonhabitat(belowMo/YSRconfluence,YSRaboveconfluence,andMoaboveconfluence)willbecollectedtargetingpallidsturgeonorsurrogatespecies.Lookingfor10ofeachsexfrombenthicspecies.Helpisneededtoscheduletrainingandsampling,perhapsJuly?LarryGamble–PallidsturgeontranslocationTranslocationisaninterimeffortatIntakeDamtobenefitpallidsturgeon.Translocationhasbeenidentifiedasarecommendationtooffsettake.USACEandUSBRaretaskedwithperformingthetranslocationsandcomingupwithdecisioncriteria.Perhapsapilotstudywouldbebestfor2017andtheshortamountoftimetoprepareastudydesign,withamoredevelopedapproachin2018.LandonHolte–Populationassessmentinsegments1-3Captured79pallidsturgeonrepresenting13ageclasses(2001-2015)in2016.2016hadreducedsamplingeffortduetoprogrambudgetcuts.Atotalof25bendsweresampledusingonlytrammelnetsandtrotlines.Noottertrawlsorfykenetswereused.Samplingin2017willbethesameas2016.Tylercommentedthattheyhaveobservedadecreaseinchubsfrom2006-2015.RyanWilson–Populationassessmentinsegment4Capturedatotalof191pallidsturgeonin2016(175HRPs,16wild).Thehabitatinthesegmenthasshifted,makingtargetedsamplingmoredifficult.2002ageclasspallidsturgeoncontinuetogrowfasterthansubsequentlystockedageclasses.Captureofsturgeon,sicklefinandflatheadchubscontinuestodecrease,asitappearsthathabitatinlong-termsamplingareahasshifted.Withfuturedevelopmentofpopulationassessmentprogram,thereisaneedtoincludeallsegmentstodetectchangesinabundanceforPallidsandotherspecies.

LandonPierce–Populationassessmentinsegment5and6Sixty-ninepallidsturgeonwerecapturedin2016.Nonewerewild.Relativeweightsvariedfrom.86-.94.The1997-1999ageclasseshadhighergrowthratesthansubsequentageclasses.Stockedpallidsturgeonsuccessfully(~94%survival)passdownstreamthroughGavinsPointDam.PSPAP2.0discussionItwasrecommendedthatallsegmentsneedtobeincludedtoseeiftherearerealtrendsinabundanceofpallidsturgeonandotherspecies.Alldatashouldbeincludedinanyanalysis.Itwasrecommendedthatmorethanjustpallidsturgeondataisneeded.Informationaboutthecommunityisneeded.Whatarepallidsturgeondoingastheymature?Wyattsuggestedweneedtostatetheassumptionsinthecurrentplanandwhatneedstobeincludedinfuturemonitoringprogramstoeffectivelymonitorstatusofpallidsturgeon.Willtheforagebasecollapseinthenext10years?Whatisthepopulation’sreproductiveviabilitylongterm?Whatdoweneedtomonitortoassessthecommunity?Recommendedobjectivesforthefuturemonitoringprogramshouldinclude:

1. Quantifyandevaluateannualtrendsinpallidsturgeonpopulationstructure.2. Quantifyandevaluateannualtrendsintheassociatedcommunitiesoffish,includingshort-term

effectsonspeciessuchaschubs.3. Thereshouldbeannualreportsandbiannualsynthesisofresults.

Danewillsendoutalistofbaselineobjectives.Tyler,Mat,Ryan,LandonandDanevolunteeredtohelpdevelopPSPAP2.0.JeffKalieandMeredithBartron–Annualpallidsturgeongeneticanalysis993sampleswereanalyzedin2016.ThreehybridswereidentifiedfromRPMA4andatriploidwasidentifiedfromRPMA2.Therearecurrently98malesinthecryo-preservationrepository.Theduedatesfor2017samplesare:

Potentialbroodstock 5/5/2017Fishofunknownoriginsforspring 6/9/2017Fishofunknownoriginsforfall 11/10/2017

MollyWebb–Determinationofreproductiveindicesincaptiveandhatchery-originpallidsturgeonThereare19ageclassesinthecaptivebroodstockatGavinsPointNFH.

SexescanbedifferentiatedatAge1.Captivebroodstockreachfirstmaturityat9years(females)and4years(males).Hatchery-originstockedfishreachsexualmaturityat18years(females)and10years(males).Typically,captivefemaleshaveatwo-yearspawningcycleandmaleshaveeitheraone-ortwo-yearspawningcycle.Femalestotargetin2017springcollectionareCode86(RPMA1)andCode203(RPMA2).Mollywillsendoutalistofneedsforfishandnecessaryequipment.RobHolm–GarrisonDamNFHIn2010stockingofpallidsturgeonmovedfrommaximizingnumbersoffishsockedtomaximizingeffectivepopulationsize.Freeembryosweresuppliedforthe2016driftstudy.MRSIV-positivefishstockedintoRPMA4appeartobesurviving.Thereisaneedtodiscussmodifyingthegeneticsmanagementplan.DomanagethegeneticstructureofeachRPMA’spopulationsoallRPMAshaveallfamilygroupsordowemanagetheUpperBasinasasinglepopulation?IsitgoodenoughiffisharerepresentedwithintheUpperBasinordotheyneedtoberepresentedinallRPMAs?WeneedtodeveloptheUpperBasin’sperspectiveinthegeneticsmanagementplan.WeneedtoprioritizeproductionoffamilygroupsbyRPMA.ChrisHooley–GavinsPointNFHNinefemalesand8maleswerespawnedfromthecaptivebroodstockin2016.AllfishspawnedarenotrepresentedinanyRPMA.RPMA1ismissingrepresenttationfrom16females.RPMA2ismissingrepresentationfrom7females.RPMA3ismissingrepresentationof6females.GPNFHisatcapacityforcaptivebroodstock.Managingforindividualfishratherthanfamilywillsaveroom.GPNFHisrehabbingandspawningcapturedadultsfromRPMA4.MikeRhodes–MilesCitySFHFincurlhasbeenanissuein2015(1of3families)and2016(allfamilies)infishheldonYSRwater.Finsarecurlingdown,whilefinsatBFTCcurledup.Whatdowedoiffincurlcontinues?

LarryGamble&WayneNelson-Stastny-USFWSUpdateItisproposedthattheRecoveryTeamLeaderbeafullyfundedposition.Thereisahiringfreeze,sotherewillhavetobean“acting”rolefor6monthsormore.Wayneunderstandstheneedtoapproacheachbasinuniquely.Intakeaffectsthestatusofpallidsturgeonbutnotconservationorimpacts.TheUSFWSmaybelookingattheUpperBasinWorkgrouptodeterminewhataretheimpactsfromFortPeckDam,bothupstreamanddownstream.LouHanebury–WAPAUpdateThereareissueswithfundingacoupleoftheprojectsproposedforWAPAfundingfor2017.Contractsshouldbecompletedinthenextseveralweeks.SteveLeathe–NorthwestEnergyUpdateNewfundsforworkinRPMA1,includingsomeequipmentandtelemetrystations;riparianrestoration;long-termripariansongbirdmonitoring;andriparianfencingbyBLM.DavidTrimpe–BureauofReclamationUpdateThefinalEISforIntakeDamhasbeencompletedandtheRODwasissuedonDecember2,2016.TheUSBRandUSACEarerequestingthattheinjunctionbelifted.AhearingisscheduledforApril5.MonitoringhasnotdetectedanyScaphirhynchusfreeembryosattheIntakeheadgate.Methodologymayneedtobeadjusted.ThereisanewNEPACoordinatorforWAPA;Kristina.PrioritiesandResearchneedsSendprioritiesorresearchneedstoZach.HewillcompilethemandsendthemtoWyatt.IncludeBartron/Kaliegeneticsprojectasaresearchneed.

UpperBasinWorkgroup2017SummaryRPMA1AnneTews,RobBeattieandMikeSchilz

March27,2018

SUMMARY

ThisreportsummarizesPallidSturgeonrecoveryeffortsfor2017inRecoveryPriorityManagementArea1(RPMA1),upstreamfromFortPeckReservoir.GametesfromonewildmaleandtwopreviouslyunrepresentedwildfemalePallidSturgeonfromRPMA1weresuccessfullyincorporatedintothe2017hatcheryprogram.Onefemalediedatthehatcheryafterspawning.Therewere414PallidSturgeoncaptures,with3wildand12fishfromthe1997-yearclass(PS-97)captured.HRPSfromPS-05throughPS-15werealsocaught.PallidSturgeoncatchrateduringthestandardfallpopulationassessmentwasthesecondhighestonrecordandwasmuchhigherthanseenforthepastthreeyears.PS-97aremuchlongeratAge9thanthenext3oldestyearclasses(PS-5,PS-06,andPS-07).Seventy-eightPallidSturgeon,primarilyPS-97,weremonitoredwithradiotelemetryin2017.FWPhad1759contactswiththesefish.Thirty-onepercentwerelocatedatleastonceupstreamofJudithLandingatrivermile(RM)1984.Oneradio-taggedmaturemalePS-97wasrecordedupstreamofFortBenton.TwoPS-97wererecordedintheMariasRiverin2017;oneatthemouthandoneatRM3.0.SurvivalofsomeyearlingHRPSyearclasseshasdeclinedinthelastthreeyears.The2013populationestimateforyearlingHRPSwas7,935(Rotella2015)andby2016,thenumberofyearlingsstillalivehaddeclinedtoabout4,100HRPSinRPMA1(Rotella,2017).FingerlingswereahighpercentageofsomeHRPSyearclassrecaptures.ApilotstudywasconductedusingShovelnoseSturgeonasasurrogatespeciestoevaluatetheutilityof23mm134kHzPITtagstotracksturgeonmovementinprairiestreams.

INTRODUCTION

TheoriginalPallidSturgeonRecoveryPlan(DryerandSandvol1993)listedthe240-milereachoftheMissouriRiverfromMoronyDamtoFortPeckReservoir(Figure1)asRPMA1.ItisnowpartoftheGreatPlainsmanagementunit(USFWS2014).FortPeckDam,completedinthe1930’s,causedthefirstmajoranthropomorphicchangesonthisreach.FortPeckdamremainsamigrationbarrier,influenceshydrologyandreducesriverinehabitat.Duringthe1950’s,additionalflowandsedimentregimealterationsoccurredduetocompletionofCanyonFerryDamontheMissouriRiverandTiberDamontheMariasRiver.In1996,therewereabout45PallidSturgeoninRPMA1.Thepopulationofsenescentadultfishshowednoevidenceofrecentrecruitment(Gardner1996).MontanaFish,WildlifeandParks(FWP)andtheU.S.FishandWildlifeService(USFWS)initiatedPallidSturgeonrecoveryinRPMA1withthereleaseof732yearlingHRPSin1998.Bysummer2016,80,504fingerlingsand34,086yearlingshadbeenstocked.In2012,yearlingstockingwasreducedtoabout300perfamilybasedonarevisedmanagementplantoincreasegeneticdiversity(Heistetal.2013).ThestockingplanhasbeenevaluatedbysamplingasmanyHRPSaspracticaltomonitorsurvivalrate,growth,movementandhabitatpreference.Mostsamplinghasbeendonewithin50milesoftheRobinsonBridge.Rotella(2015)

estimatedtheHRPSpopulationat7,935with95%CIof(6231–9630)in2013.By2016,therewereabout4,100HRPSremaininginRPMA1(Rotella,2017).

METHODS

PallidSturgeonsamplingmethodsincludedtrammeldriftnetting,setlinesandtrawling.SeeTewsandGardner(2014)formethoddetails.In2017,trammelnettingconsistedofdriftnettingontheMissouriasfarupstreamasrivermile(RM)2042andonthelowest20milesoftheMariasRiver,targetedbroodstocknettingandtheannualPallidSturgeonassessmentof50trammelnetsetsfromRM1907to1925.3.HRPSwereidentifiedtoyearclassandfamilywith125HzPITtags.AnewPITtagwasinstalled,andageneticsampletakenfromPallidSturgeonwithouttags.PallidSturgeonrelativeconditionfactor(Kn)wasusedtoevaluatecondition(Shumanetal.2011).In2017,78PallidSturgeonweremonitoredwithradiotelemetry.Thesefishhadcontinuouscoveragefrom13fixedremoteradioreceivingstationslocatedthroughoutthestudyarea,including2tributaries(Figure1).Manualboattelemetrytrackingwasalsocompletedatleastmonthlyduringthefieldseason.Bloodwascollectedfromwild,PS-97andsomeotherHRPSforastudyonreproductivestatusconductedbyDr.MollyWebbattheUSFWSBozemanTechCenter.

RESULTS

Thestudyareagenerallyhadflowconditionsnearthemedianin2017,butrun-offoccurredearly(Figure2).In2017,2,136springyearlingsfromGarrisonDamNationalFishHatcheryand413fromtheMilesCityFishHatcherywerestocked.Thesefishwereprogenyfrom4femalesand11males.About50%ofthefishwerestockedatLomaand50%atRobinsonBridge.MostoftheMilesCityhatcheryraisedPallidSturgeon(HRPS)hadfincurl.Stockingrateswerebasedonthemediannumberof329fishstockedpermaleparent.Fingerlingswerenotstockedin2017.GametesfromonewildmaleandtwopreviouslyunrepresentedwildfemalePallidSturgeonfromRPMA1weresuccessfullyincorporatedintothe2017hatcheryprogram.Onefemalediedatthehatcheryafterspawning.Therewere414PallidSturgeoncaptures(Table1),with3wildand12fishfromthe1997-yearclass(PS-97)captured.HRPSfromPS-05throughPS-15werealsocaught.In2017,199geneticssamplesweresubmittedtotheUSFWSatLamarPA.FourofthesefishwerenotmarkedandgeneticstestswerenecessarytoconfirmtheywereHRPS.One299mmlongPS-15diedduringspringsetlining.BloodsamplessenttotheBozemanFishTechnologyCenterforhormoneanalysisincluded;2fromwildfish,15fromPS-97and8fromotheryearclasses.

Springsetlines:In2017,259PallidSturgeonwerecaughtbysetlines(Table1).Standardized

springsetlinesamplinghasbeenconductedintheRobinsonSectionsince2008(Figure3).In2017,PallidSturgeonsetlinecatchrateswerethehighestonrecordandwasthemostcommonspeciescaptured.

FallPallidSturgeontrammelnetsurvey:Therewere103PallidSturgeonsampledduringthe

2017standardizedfalltrammelnetsurveyinthe16-mileRobinsonBridgetrendarea(Table2).Samplingconditionswereexcellent.PallidSturgeonCPUEwasthesecondhighestonrecordandwasmuchhigherthanseenforthepastthreeyears.ShovelnoseSturgeoncaptureratesincreasedtothehighestobservedsince2013andwerenearaverage(Figure4,Table2).

Figure1.MapofRPMA1,theMissouriRiver,aboveFortPeck.

Figure2.FlowsattheFredRobinsonBridgein2017comparedwithlongtermmedian.DatafromtheUSGSwebinterfaceNovember30,2017.

Size,yearclassstructureandsurvival:From2005–2009therewereover4,000yearlingsstockedannually,butHRPScatchratehasnotbeenconsistentwithstockingrates(Figure5).PS-09hasconsistentlybeenthestrongestyearclassandhascomprisedmorethan20%oftheHRPScatchsince2013.Incontrast,thePS-07classhadthehighestyearlingstockingdensitybuthasconsistentlyrepresentedlessthan10%ofthefishcapturedCatchratesofmostrecentyearclassesappeartoberelatedtostockingdensities.AverageHRPSforklengthfordifferentstockingcohortsdemonstratestheslowgrowthofallbutthePS-97ageclass(Figure6).Assessmentoftheparameters,suchasstockingdensity,thatcauseslowgrowthwouldbenefitrecovery.Despiteslowgrowth,HRPSofallyearclasseshavemaintainedandevenimprovedtheirconditioninrecentyears.In2017,Knofallsizeclasses,exceeded0.9(Figure7).SurvivalofsomeyearlingHRPSyearclasseshasdeclinedinthelastthreeyears.The2013populationestimateforHRPSyearlingswas7,935(Rotella2015)andby2016,thenumberofyearlingsstillalivehaddeclinedtoabout4,100HRPSinRPMA1(Rotella2017).ThisnumberisanunderestimateofthetotalHRPSpopulation;fingerlingswerenotincluded.Thenumberoffingerlingscapturedhasincreasedsubstantiallyinrecentyears(Table3)andfingerlingrecapturesareahighpercentageofsomeHRPSyearclasses(Table3,Figure5).Modelsusedinfuturesurvivalestimatesshouldincludethesefish.

RadioTelemetry/Movements:In2017,78PallidSturgeon,including67PS-97,2PS-05,1PS-09

and8wildfishweremonitoredwithradiotelemetryinRPMA1.ManualboattrackingwascompletedatleastmonthlyfromApril–October;1931boattrackingmileswereloggedin2017for618PallidSturgeonrelocations,including135exactlocations(Tewsetal.2018).Atotalof1,141PallidSturgeonrelocationswererecordedat11ofthe14remotestations.TrackinghistoryofthreewildfemalePallidSturgeonmonitoredfrom2016–2017isshowninFigure8.TwowildfemalesmademigrationsfromRobinsonBridgetoaboveCoalBanksduringnon-spawningyears.Thethirdremainedwithin30milesofRobinsonBridge.ThewildmalePallidSturgeoninRPMA1migratedowntotheRobinsonBridge/PowerPlantareainlateMay,stayforapproximatelyonemonthandthenreturntotheirhomelocationsatRM2010,1988,1970and1955(Figure8).SexuallymaturePS-97appeartomovefrequentlywithin20milesofRobinsonbridgeduringthespawningseason,whileimmaturePS-97hadtwotypicalpatterns;onewithmovementstypicallywithin30milesofRobinsonBridgeandonewithlongdistancemigrationstoanewlong-termterritory(Figure9).ForPS-97,31%wererelocatedupstreamofJudithLanding(RM1984).PercentagesweresimilarforwildPallidSturgeon.Oneradio-taggedmaturemalePS-97wasrecordedupstreamofFortBenton.TwootherHRPSwerecapturedabovetheMariasRiver;includingonenearthemouthofHighwoodCreek.Tworadio-taggedPS-97wererecordedintheMariasRiverin2017;oneatthemouthandoneatRM3.0.ThreePallidSturgeonwerecaughtintheMariasRiver.OnePS-07andonePS-08werecaughton6/14atRM7.6andaPS-13wascaughton7/6atRM0.6.Allthreefishwerestockedasfingerlings.TwowerestockedatRobinsonBridgeandthestockinglocationofthirdfingerlingisnotknown.ThePS-07waspreviouslycaughtatRM1918in2012andthePS-13waspreviouslycaughtatRM1906and1910in2015.Itissurprisingthatthesefishmigratedsofarupstreamatanearlyage.

PilotPITtagStudy:HDX23mm134.2kHztagswereinstalledintheperitonealcavityofShovelnoseSturgeon,BlueSuckersandseveralotherspeciesin2016and2017toevaluatefishmovementsintotheLowerMariasRiver.ShovelnoseSturgeonwereusedasasurrogateforPallidSturgeonandwerethefocusofthestudy.OnApril20,2017,aPITtagarraywithtwoantennaewasinstalledatRM1.0ontheMariasRiver.FromMay9–November9therewere608“hits”onthePITtag

stationfrom260differentfish.OnehundredandninefishrecordedatthestationwereoriginallytaggednearCoalBanksand143weretaggedintheMarias.Atotalof22.4%ofthetaggedCoalBanksShovelnoseSturgeonand54.3%oftheShovelnoseSturgeontaggedintheMariaswererecordedatMariasRM1.0.TagRetentionwithperitonealinstallationwasexcellentformatureShovelnoseSturgeon.OnehundredpercentoftheShovelnoseSturgeonwithexternaltagsnettedinSpring2017,thatwerePITtaggedin2016(N=5),hadretainedtheirPITtags;notaglosswasdocumented.In2017,datawasonlycollectedatthelonger,northantenna,duetoitsinterferencewiththesouthantenna.ThereweresomeinitialreadingissueswiththePITArrayandthestationwasnotrecordingateitherantennafromMay24–June13,2017.However,thepercentageoffishrecorded,despiteonlypartialcoverageoftheMariasisimpressive,consideringthatfishpassageinthethalweg(southantennae)wasnotmonitored.Thereturnrateofonly50%offishtaggedintheMariasRiverwaslikelyduetothispartialcoverage.Readrangeoftheantennawasusuallygood;forexample,itwas15inchesonJuly21.

RECOMMENDATIONS

1. ContinuethestockingevaluationofHRPSincorporatingmultiplesamplingmethods,includingsetlinesandfalltrammelnetting.

2. ContinuetoevaluateHRPSsurvivalusingupdatedmodelsthatincludefingerlings.3. IncreasePallidSturgeonsamplingupstreamofthecurrentfocusarea(RM1930).4. UseradiotelemetryinconjunctionwithhormoneanalysistodeterminelocationofPallidSturgeon

spawningareas.Additionalfundingisnecessarytofindspawningareas.AWesternAreaPowerfundedMontanaStateUniversityMaster’scandidatewillfocusonthisworkstartingin2018.

5. ConsiderachangeofPITtagfrequencytothecurrentstandardof134.2kHz.6. Evaluateperitonealinsertionof23mmPITtagsinPallidSturgeontoenablemonitoringofHRPS

movements.

Figure3.CatchratesofcommonspeciescapturedduringspringsetlininginRPMA1,2008–2016.

Table1.NumberofPallidSturgeoncaptured,bymethod,intheMiddleMissouriRiver,MTaboveFortPeckReservoir2017.

Method

YearClass Setline Other Trammel Total

1997 2

2005 5 1 5 11

2006 16 5 6 27

2007 13 2 4 19

2008 27 8 12 47

2009 102 7 21 130

2010 25 4 6 35

2012 5

2013 16 1 7 24

2014 17

2015 31

1 14 15

Unknown

Total 259 29 126 414

Table2.SamplingstatisticsfortheannualPallidSturgeonassessment,nearRobinsonBridge,intheMiddleMissouriRiver,MT,1996-2017,comparedwithPallidSturgeoncapturedbyFWP2008–2017.

(1996-

2007) 2008 2009 2010 2011 2012

2014 2015

2016 2017

PallidSturgeon

#Sampled 6.8 28 42 39 39 99 106 14 67 61 103

#Wild 0.6 0 0 0 0 0 0 0 0 0 0

#HRPS 6.0 28 42 25 39 99 106 14 67 61 103

Mean#/drift 0.13 0.56 0.82 0.50 0.78 1.98 2.12 0.21 1.34 1.22 2.06

All(RPMA1) 146 271 347 302 334 451 217 257 229 414

ShovelnoseSturgeon

#sampled 210 222 227 173 125 226 253 80 108 155 181

Averageweight(g) 1477 1693 1612 1838 1924 1884 1871 1862 1842 1797 1904

number/drift 4.2 4.4 4.4 3.5 2.5 4.5 5.1 1.25 2.2 3.1 3.6

Driftnetsamplinginformation(mean)

Drifttime(min) 6.8 6.8 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0

#ofdrifts 50 50 50 50 50 50 64 50 50 50

Driftdistance(m) 262 262 303 291 272 215 278 376 320 284 354

Depth(m) 1.9 1.6 1.7 2.0 2.4 2.0 1.7 2.7 1.8 1.9 1.8

Table3.PercentofHRPSknownfingerlingscomparedtoknownyearlings,capturedbyyearandbyyearclassforfishcaptured2005–2017.

CaptureType N%Fingerlingsby

Captureyear

2006 3 3.7

2007 3 1.8

2008 1 0.7

2009 4 1.5

2010 23 6.8

2011 24 8.3

2012 29 9.0

2013 53 13.1

2014 32 17.0

2015 47 16.2

2016 35 13.0

2017 91 23.9

Total 345

Yearclass

2005 15 2.8

2006 0 0

2007 23 7.7

2008 60 13.0

2009 133 24.3

2010 53 39.5

2012 0 0.0

2013 9 19.6

2014 13 25.4

2015 36 53.7

2016 3 15.4

Total 345

Figure4.PallidSturgeonandShovelnoseSturgeoncatchratetrendforfalltrammelnettingpopulationassessmentsurveysconductedintheMiddleMissouriRiver,1996–2016.

Figure5.Percentofcatchbyyearclassin2013–2017comparedwithtotalnumberofyearlingfishstockedbyyearclass,showingyearclasseswithhighfingerlingnumbers.

Figure6.MeanforklengthofknownageHRPSthroughage12.PS-97averaged1052mmforklengthatAge20in2017.

Figure7.PallidSturgeonconditionbysizeclassinRPMA1.Stock330-629mm;Quality630–839mm;Preferred840–1039mm;Memorable1040–1269mm;Trophy≥1270mm.Trophyfishareallwild,MemorablearegenerallyPS-97;SizeclassesandKnformulafromShumanetal.2011.

Figure8.MovementsofwildPallidSturgeoninRPMA1forfishmonitoredin2016and2017.

Figure9.Movementpatternsofnon-reproductivePS-97taggedin2012and2013,comparedwithPS-97thatwerematureby2017.

REFERENCES

Dryer,M.P.andA.J.Sandvol.1993.Recoveryplanforthepallidsturgeon(Scaphirhynchusalbus).U.S.FishandWildlifeService.Bismarck,ND.

Gardner,W.M.1996.MissouriRiverpallidsturgeoninventory.MontanaFishWildlifeandParks.Fed.AidtoFishandWildlifeRest.Proj.F-78-R-2.Helena.

Heist,E.and4others.2013.PopulationGeneticsManagementplanforpallidsturgeonintheUpperMissouriBasin.ForWesternAreaPower.

Rotella,J.2015.UpperBasinPallidSturgeonSurvivalEstimationProject–2015UpdateReporttoUpperBasinPallidSturgeonWorkgroup.Revised2015.

Rotella,J.2017.UpperBasinPallidSturgeonSurvivalEstimationProject–2017UpdateReporttoUpperBasinPallidSturgeonWorkgroup.Revised2017.

Schuman,D.A.and11others.2011.Pallidsturgeonstructure,condition,andgrowthintheMissouriRiverBasin.JournalofAppliedIchthyology27:269–281.

Tews,A.andW.M.Gardner.2014.MiddleMissouriFisheriesEvaluations.2007–2013Report.MontanaFishWildlifeandParks.FederalAidF113/R7-R13.

TewsA.,M.SchilzandR.Beattie.2018.MissouriRiverRadioTelemetryandUSBR2016and2017ProgressReport.ForFWP,USBRandNorthwesternEnergyCompany.

ACKNOWLEDGEMENTS

NateBeckman,KatieVivian,GrantGrisak,JasonMullanandMarySchvetzofMFWPandSteveLeathe(NWE)assistedwithfieldwork.ThanksalsotoDr.MollyWebbandherlabforevaluatinghormonelevelsinsturgeonbloodandevaluatingspawningstatus.SpecialfundingforthisprojectwasprovidedbytheUSBRandNWE.AdditionalfundingwasprovidedbyMFWP,WesternAreaPowerAuthorityandtheUSFWS.

2017AnnualReport

PallidSturgeonPopulationAssessmentandAssociatedFishCommunityMonitoringfortheMissouriRiver:Segment2

PreparedfortheU.S.ArmyCorpsofEngineers–MissouriRiverRecoveryProgram

JohnHunzikerandTylerHaddix

MontanaFish,Wildlife&Parks

POBOX165

FortPeck,MT59223

March2018

EXECUTIVESUMMARY

The2017fieldseasonmarkedthe12thconsecutivesamplingyearforPallidSturgeonPopulationAssessmentcrewsinSegment2oftheMissouriRiver.Althoughthiswasthe12thyearofsampling,itwasalsothesecondconsecutiveyearofareductioninsamplinggears.Neithertheottertrawlormini-fykenetwasusedinsamplingduringthe2016or2017fieldseason.Samplingeffortswiththetwostandard

gears,trammelnetandtrotline,ledtothecaptureof31pallidsturgeon,allofwhichwereofhatcheryorigin.

Atotalof12randomlyselectedriverbendsweresampledinSegment2during2017.All12bendsweresampledwithtrammelnetsduringbothsturgeonandfishcommunityseasons.Comparatively,trotlineswereusedtosampleeachbendonce;withhalfofthebendssampledduringsturgeonseasonandtheotherhalfsampledduringthefishcommunityseason.Atotalof205trammelnetsweredriftedthroughoutSegment2in2017,whichaccountedfor48.2kmofsampling.Additionally,usingthestandardsamplingmethodofeighttrotlinesperbend,atotalof96trotlinesweredeployed,totaling1,960nightcrawler-baitedhooknights.

Atotalof31pallidsturgeonwerecapturedinSegment2duringthe2017fieldseason,allofwhichwereofhatcheryorigin.Temporally,morepallidsturgeonwerecapturedduringsturgeonseason(n=17),thanfishcommunityseason(n=14).Trotlinewasthemostsuccessfulgearatcapturingpallidsturgeon,resultingin20observations,whiletrammelnetdetectedanadditional11individuals.Pallidsturgeonweredetectedinfiveofthe12randomlyselectedtrammelnetbends.Incomparison,pallidsturgeonwerecapturedinsixofthe12randomlyselectedtrotlinebends.Additionally,samplingeventsatlocalizedspotsonceagainbolsteredtotalcaptures,with23%ofthetotalcomingfromasinglebendduringfishcommunityseason.

TrammelnetCPUEforthe2017fieldseasonthroughoutSegment2wastabulatedat0.02fish/100mforallthreeseasonalmetrics(sturgeon,fishcommunity,andcombinedseasons).TrotlinecapturesledtoCPUEsof0.26fish/20hooksand0.17fish/20hooksforthesturgeonandfishcommunityseasons,respectively.Acombined-seasonCPUEwasestimatedat0.21fish/20hooknight.

PallidsturgeonhandledinSegment2duringthe2017fieldseasonaveraged471mminforklengthandaveraged440ginweight.Lengthsrangedfrom372mmto957mmforklength.Trammelnetscapturedonaveragelargerindividuals(513mm)thandidtrotlines(448mm).Thevastmajority(94%)ofpallidsturgeoncapturedin2017fellintothestocksizecategory,whiletheother6%(n=2),wereinthepreferredsizedesignation.Nomajorvariationsinrelativeconditionwereobservedbetweenthetwosizedesignations.

Ofthe31pallidsturgeonsampledinSegment2duringthe2017fieldseason,allbutonewereofaknownyearclass.Yearclassesinrankofabundancewere;2006(n=8),2008(n=7),2009(n=6),2010(n=4)and1997,2003,2007,2015,and2016wereallrepresentedbyoneindividual.Inregardtostockinglocation,27ofthe31pallidsturgeoncapturedthroughoutSegment2duringthe2017fieldseasonweretiedtoaknownstockinglocation.Inrelationtostocking-river,morepallidsturgeonoriginatedfromtheMissouriRiver(n=17)thanoriginatedfromtheYellowstoneRiver(n=10).Stockinglocationinrankofabundancewere;WolfPoint(n=9),Culbertson(n=8),Fallon(n=4),Intake(n=3),Sidney(n=2),andForsyth(n=1).

ShovelnosesturgeonobservationsinSegment2oftheMissouriRiverwereonceagainacommonoccurrenceduringthe2017fieldseason.Atotalof536shovelnosesturgeonwerecapturedin2017,whichwasmorethananyotherspecies.Seasonally,aslightlyhigherproportionofshovelnose

sturgeon(n=276)werecapturedduringsturgeonseasonwhencomparedtofishcommunityseason(n=260).Inrelationtogears,trammelnetscapturedmoreshovelnosesturgeon(n=363)thandidtrotlines(n=173).

TrammelnetCPUE,regardingshovelnosesturgeonofthequalityorgreatersizeclass,wasrecordedas0.68fish/100mforboththesturgeonandfishcommunityseasons,respectively.IdenticalseasonalCPUEsinturnledtoacalculatedcombined-seasonCPUEof0.68fish/100m.TheobservedtrotlineCPUEwastabulatedat1.96fish/20hooksand1.73fish/20hooksforthesturgeonandfishcommunityseasons,respectively.Thecombined-seasonCPUEwasthencalculatedtobe1.84fish/20hooks.DuetothesizestructureoftheshovelnosesturgeonpopulationsampledinSegment2,trammelnetandtrotlineCPUEremainedverylowforthestockandsub-stockcategories.

Theshovelnosesturgeonobservedduringthe2017fieldseasonthroughoutSegment2averaged608mminforklengthand898ginweight.WiththerarityofsmallersizeclassesofshovelnosesturgeonresidinginSegment2,observedaveragelengthhasremainednearlyidenticalovertime.Therelativeweightforboththestockandqualitysizeclassesofshovelnosesturgeonremainshighlyvariableduetolowsamplesize.Conversely,therelativeweightforthepreferredandmemorable/trophysizeclassofshovelnosesturgeoninSegment2hasremainedmuchmorestableandcomparable

Atotalof10bluesuckerswerecapturedinSegment2duringthe2017fieldseason;allofwhichwerecapturedviatrammelnetduringrandomdeployments.Temporally,morebluesuckerswerecapturedduringsturgeonseason(n=6),whencomparedtofishcommunityseason(n=4).ReportedtrammelnetCPUEof0.03fish/100mand0.02fish/100mforthesturgeonandfishcommunityseasons,respectively,ledtoacombined-seasonCPUEof0.02fish/100m.Thebluesuckersobservedduringthe2017fieldseasonaveraged648mmintotallengthand2,801ginweight.IthasremainedtypicalinSegment2thatbluesuckercatchesaredominatedbylarge,adultindividuals.

Atotalof125saugerwerecapturedthroughoutSegment2duringthe2017fieldseason.Nearlyallsaugerwereobservedviatrammelnet,sansaloneindividualrepresentedbyatrotlinecapture.Moresaugerwerecapturedduringsturgeonseason(n=103),thanduringfishcommunityseason(n=22).Thecombined-seasontrammelnetCPUEforwasrecordedat0.25fish/100m.Seasonally,CPUEwastabulatedat0.42fish/100mand0.09fish/100mforthesturgeonandfishcommunityseasons,respectively.Thesaugercapturedin2017seasonaveraged350mmintotallengthand327ginweight,witharangefrom222mmto518mm.

Withthesuspensionoftheottertrawlandmini-fykenetassamplinggearsforthe2016and2017fieldseasons,noneofthesmall-bodiedtargetspecies(sturgeonandsicklefinchubs,Hybognathusspp.,andsandshiner)wererepresentedinthecatchdataforSegment2.

2017MissouriRiverSamplingfromtheYellowstoneConfluencetoLakeSakakawea

USFWSBismarck,ND

TheMissouriRiverbelowtheconfluenceoftheYellowstoneRiverisahighlydynamicsystemandfeaturesadiverseassemblageofhabitatsthattypifythehistoricconditionsoftheriver.TheinfluenceoftheYellowstoneRiverandtheseasonalfluctuationsinthehydrograph,includingtheimmensesedimentload,greatlyinfluencethefishcommunity,includingthepallidsturgeon.TheelevationofLakeSakakaweaalsoinfluencesthelowerportionofsegment4.TheUSFWSMissouriRiverFishandWildlifeConservationOfficeinBismarckbegansamplingthetwelverandomriverbendsofsegment4onthe17thofAprilandcompletedsamplingonthe14thofOctober.Over71,000metersweredriftedwithtrammelnetswhichincludednearly42,000metersduringatargetedsamplingeffort.Ottertrawlsweretowedonly4,361metersduringthesturgeonseasonduetohighflowsfromtheYellowstoneRiverinMaywhichresultedinunsafesamplingconditions.26,366metersweretrawledduringthefishcommunityseason.Additionally,minifykenetsweresetin12bendsduringthefishcommunityseasonandtrotlinesweredeployedin12randombendsduringfishcommunityseason.Pallidsturgeon(Scaphrynchusalbus)istheprimarytargetofthissamplingeffort.Onehundredseventyfivehatcheryreleasedandthreewildadultpallidsturgeonwerecapturedinsegment4in2017.Thiswaslessthan2010(N=724),2014(N=440),2015(N=435)and2016(N=180)butwasthefifthmostcapturedinthirteenyearsofsampling.Followingstandardprotocolswecaptured47pallidsturgeonintwelverandombendswithtrammelnets.Trotlinescaught64hatcheryreleasedpallidsturgeonwhile14weresampledwiththeottertrawl.Additionally,26hatcheryreleasedpallidsturgeonwerecapturedduringathreedaytargetedsamplingeffortwithtrammelnetsinthelowersectionofsegment4.Pallidsturgeonfromall18yearclassesthathavebeenstockedinRPMA2werecollectedin2017.Pallidsturgeonfrom9stockinglocationsusedwithintheMissouriandYellowstoneRiversabovetheconfluenceweresampledwiththemajority(58%)originatingfromYellowstonestockingsites.Relativeconditionfactorforallpallidsturgeoncapturedduringthiseffortrangedfrom0.95to1.02.Growthratesforrecapturedjuvenilesturgeonrangedfrom0.06to0.313mm/daywithyoungersturgeonshowingahighergrowthrate(Table4).Atotalof418shovelnosesturgeonS.platorynchusweresampledduringthe2017samplingseasoninsegment4.Themajorityweresampledintrammelnets(N=319)followedbytheottertrawl(N=80)andtrotlines(N=19).Thirtyage-0shovelnosesturgeonwerecapturedin2017.Qualityandabovesizeclassfishcontinuedtoaccountforthemajorityshovelnosesturgeonsampled.In2017,sixoftheeightnativeMissouriRiverspeciesthatweretargetedforthisassessmentweresampled.SturgeonchubMacrohybopsisgelidaweresampledinottertrawls(N=119).Atotalof111sicklefinchubsM.meekiwerecollectedinsegment4withallsicklefinchubsbeingcapturedintheottertrawl.Westernsilveryminnows,Hybognathusargyritis,werecapturedduringthefishcommunityseasoninmini-fykenets(N=60)andtheottertrawl(N=6).Atotalof17bluesuckersCycleptuselongateswerecollectedintrammelnets(N=16)andtheottertrawl(N=1).Noyoungoftheyearbluesuckerswerecollected.SaugerSandercanadensewerecapturedinallgearsduringbothseasons.Trammelnetscapturedthemostsauger(N=155),followedbytheottertrawl(N=20)andmini-fykenets(N=19).ShoalchubsM.aestivalisandsandshinerNotroposstramineusweretheonlytargetednativespeciesnotcapturedinanygear.Sandshinerswerecollectedin2005,2006,2007,2008,2009

and2013.Shoalchubshavenotbeensampledinsegment4in13yearsofsampling.Atotalof22,380fishrepresenting30speciesweresampledinsegment4oftheMissouriRiverduring2017.

LowerYellowstoneRiverPallidSturgeonProgressReport

Periodcovered:January2017–December2017

Author:MathewRugg

LowerYellowstoneRiverBiologist

MontanaFish,Wildlife&Parks

Glendive,MT59330

(218)205-6132

email:mrugg@mt.gov

MultiplePallidSturgeonresearchandrecoveryactivitiesoccurredontheYellowstone

Riverduring2017including:telemetrytrackingofadultsandjuvenilestoassessspawning,

habitatuse,andpassagelimitations,andjuvenilesamplingtocontinuehistoricaltrenddataand

aidinthecomputationofsurvivalestimatesofhatcherystockedindividuals.

YellowstoneRiverdailywaterdischargeduring2017nearSidney,MTwasatorabove

thehistoricmediandailydischarge(Figure1).Thespring-pulseonsetbeganearly,inFebruary,

andremainedabovehistoricmedianflowsthroughthemid-Junepeak(57,300cfs)largelydueto

increasedflowsoutoftheBighornRiver.SpringdischargeoutoftheBighornRiverin2017was

2-4timesgreaterthanthehistoricaveragedischarge,anddischargeremainedabovehistorical

averagesthroughouttheentiretyof2017.YellowstoneRiverdischargewasalsogreatly

influencedbytheabundanceofwatercomingfromtheBighornRiverthroughout2017.

PALLIDSTURGEONPOPULATIONMONITORING

Annualtargetedmonitoringofhatchery-rearedPallidSturgeonwasconductedusing

driftedtrammelnets(6’X100’;1”barmesh)fromlateJulytolateSeptember.Thedataderived

fromtheseeffortsareusedinmultiplewaysincludingtheestimatingsurvivalofstockedPallid

Sturgeon.Survivalestimatesutilizingthesedataandbydatacollectedbyotherfieldcrewswere

originallygeneratedin2009(Hadley&Rotella2009)andhavebeenupdatedperiodicallywith

capturehistoriesfromsubsequentyears(Rotella2010,Rotella2012,Rotella2015,Rotella

2017).BluffpoolhabitatsbetweenIntakeDiversionDam(Intake)andtheconfluencewiththe

MissouriRiverhavebeentraditionalfocalpointsofourefforts.However,arecentinfluxof

juvenilePallidSturgeonequippedwithradiotransmittersandmanyrelocationsoutsideofthe

traditionalbluffpoolhabitatspromptedtheexpansionof2017samplingintoadiversityof

habitatsincludingrifflesandruns.

RESULTS

In2017,528trammelnetsweredeployed,yieldingatotalnettingeffortof

approximately120hoursand320kmdrifted.Ninety-OnePallidSturgeonwerecaptured

ranginginsizefrom329mmto1371mm.Lengthgroupsfrom300mmthrough1000mmwere

allwellrepresented,andseveralindividualslargerthan1200mmwerealsocaptured(Figure2).

Incrementalrelativestockdensity(RSD)includedthepresenceofmorepreferredsizeandlarger

PallidSturgeonthananyofthepast5years(Figure3).PallidSturgeoncatchratebyhour(0.71

fish/hr)andbydistance(0.29fish/km)remainedlowcomparedtothe10-yearaverage,butthe

catchtrendcontinuestocloselymatchthestockingtrend(Figure4).Thatis,thehighestcatch

ratesinthepast10yearshaveallcoincidedwithrelativelyhighnumbersofPallidSturgeon

stocked(Figure4).Reducedcatchratesinrecentyearsarepotentiallyduetoachangein

stockingstrategythathasdrasticallydecreasedthenumberofhatchery-reared,juvenilePallid

Sturgeonstockedinanattempttoalleviatepotentialcarry-capacityconcerns.Conditionfactor

(Kn)ofallPallidSturgeonsizecategories,excepttrophy-sized,remainedatorslightlybelow1.0

(Figure5).Trophy-sizedPallidSturgeonconditionfactorhasbeenatorwellabove1.0;

however,mosttrophy-sizedindividualsthatwerecapturedwereinspawningconditionand

theirconditionfactorwaspositivelyinfluencedbythepresenceoffullymaturegonads.

Forty-twogeneticsamplesand35bloodsamplesweretaken,and37radiotransmitters

wereimplantedintoPallidSturgeonduring2017.Geneticsampleswillbeusedtodetermine

theoriginofunmarkedindividuals(e.g.hatcheryorwildproduced)aswellastoassign

parentagetothosewithoutindividuallyuniquemarkings.Plasmaextractedfrombloodsamples

willbeanalyzedforsexsteroidstoestimatematurity.Radiotransmitterswillbeusedto

subsequentlytrackandpotentiallyrecapturePallidSturgeontoassessmaturation,habitatuse,

spawningmigrations,dampassage,etc.

TARGETEDPALLIDSTURGEONMONITORINGUPSTREAMOFINTAKE

Monitoringofhatchery-rearedPallidSturgeonupstreamofIntakebeganin2011and

hasbeenrepeatedannuallythereafter.Previoustelemetryinvestigationssuggestedsuitable

PallidSturgeonhabitatwasavailableupstreamofIntake,andthefrequencyandgeographic

rangeofPallidSturgeoncapturesupstreamofIntakehasincreasedinrecentyears.Trammel

nets(6’x100’;1”barmesh)weredriftedprimarilyinbluffpoolsandlongrunsbetweenthe

PowderRiverConfluenceandStipekFishingAccessSite.

RESULTS

SixdaysofnettingeffortaboveIntakeresultedin75totaltrammelnetdriftsthat

equatedto21.0nettinghoursand60.4kmdrifted.Theeffortresultedinthecaptureof331

ShovelnoseSturgeonand8PallidSturgeon.TheresultantPallidSturgeoncatchrateabove

Intakeduringthesturgeon-targetedeffortwas0.38fish/hrand0.13fish/km,whileShovelnose

Sturgeoncatchratewas15.8fish/hrand5.5fish/km(Figure6).Comparatively,PallidSturgeon

catchrates(0.78fish/hr;0.32fish/km)andShovelnoseSturgeoncatchrates(37.7fish/hr;15.7

fish/km)downstreamofIntakeweregreaterthanthoseupstream(Figure6).PallidSturgeon

capturedupstreamofIntakerangedinsizefrom394mmto915mm;however,thesize

distributionwasheavilyskewedtowards300and400mmlengthgroups(Figure7).

MIGRATIONPATHWAYS,HABITATUSE,ANDREPRODUCTIONOFPALLIDSTURGEON

ThiswasyearsixofacollaborativeeffortbetweenU.S.GeologicalSurvey(USGS)and

MontanaFish,Wildlife&Parks(FWP)investigatingandassessingmigrationpathways,habitat

useandreproductionofPallidSturgeonintheYellowstoneRiver.Theresearchneedstemsfrom

recoveryeffortstoattainpassageatIntake,wherelimiteddataareavailableregarding

migrationsandreproductionofPallidSturgeon.Additionally,thedatawillbeutilizedtoderive

comparisonofPallidSturgeonmigrationsinthenaturalYellowstoneRivertothoseofthelower

channelizedMissouriRiver.EffortstomonitorPallidSturgeonreproductionintheYellowstone

Riveriswarrantedtoexaminetemporalperiodicityofspawningeventsinrelationto

environmentalconditionsandtoquantifyspecifichabitatonspawninggroundsinanatural

system.Objectivesoftheresearchwere1)examinemigrationpathways,timing,extent,main

andsidechanneluseandapproachtoIntake2)analyzehabitatuse-depthsandvelocities3)

documentspawningtiming,habitatandlocation4)documentthehatchofembryos.

BeginninginearlyApril,manualtrackingrunswereconductedfortelemeteredadult

PallidSturgeonontheYellowstoneRiveratintervalsrangingfromonceperweektoonceper

day.Trackingdatawillbesupplementedwithanetworkoftelemetrygroundstationsthat

coverstheYellowstoneRiverfromForsyth,MTtotheconfluencewiththeMissouriRiver,and

theMissouriRiverfromtheMilkRivertotheconfluencewiththeYellowstoneRiver(Figure8).

AdetailedreportofallfindingswillbeproducedbyUSGSbySpring2018.

ADDITIONALMISCELANNEOUSPALLIDSTURGEONACTIVITIES

• CrewsassistedwithPallidSturgeonBroodstockcollectioninthelowermostreachesof

theYellowstoneRivernearitsconfluencewiththeMissouriRiver.Crewscapturedtwo

wild,adultmalesthatwassentintothehatcherysystemforpropagation.

• Crewsattendedanoil-spillpreparationworkshopheldbyUSFWSandUSGSthat

includedshortinstructionalpresentationsonproceduralpracticesthatcouldbe

implementedshouldanoil-spilloccurinPallidSturgeonrange.Theworkshopalso

includedatwo-daysamplingeffortdirectedatcollectingwholeShovelnoseSturgeonto

beeuthanizedandbloodsamplesfromPallidSturgeon.Tissueandbloodsampleswill

beanalyzedbyUSFWSandUSGStoprovideabaselineoccurrenceofhydrocarbonsin

sturgeonspeciesintheYellowstone-MissouriRiversystem.FWPRegion7crews

collected7bloodsamplesfromPallidSturgeonforthiseffort.

• BureauofReclamation(BOR)initiatedPallidSturgeontranslocationeffortsin2017as

dictatedbytheIntakeBiologicalOpinion.FWPcrewstrainedBORstaffontheprotocols

forlocating,netting,andassessingadultPallidSturgeon.

LiteratureCitedHadley,G.L.,andRotella,J.J.2009.UpperBasinPallidSturgeonPopulationEstimationProject.

FinalReportsubmittedtoUpperBasinPallidSturgeonRecoveryWorkgroup.Rotella,J.J.2010.UpperBasinPallidSturgeonSurvivalEstimationProject–2010Update.Final

ReportsubmittedtoUpperBasinPallidSturgeonRecoveryWorkgroup.Rotella,J.J.2012.UpperBasinPallidSturgeonSurvivalEstimationProject–2012Update.Final

ReportsubmittedtoUpperBasinPallidSturgeonRecoveryWorkgroup.Shuman,D.A.,D.W.Willis,andS.C.Krentz.2006.ApplicationofaLength-Categorization

SystemforPallidSturgeon(Scaphirhynchusalbus).JournalofFreshwaterEcology.Volume21,Number1.

Shuman,D.A.,R.A.Klumb,R.H.Wilson,M.E.Jaeger,T.Haddix,W.M.Gardner,W.J.Doyle,P.T.

Horner,M.Ruggles,K.D.Steffenson,S.StukelandG.A.Wanner.2011.Pallidsturgeonsizestructure,condition,andgrowthintheMissouriRiverBasin.JournalofAppliedIchthyology(27),269-281.

Figure 1. Yellowstone River daily mean discharge for 2017 and historic daily median discharge near Sidney, Montana (USGS gaging station 06329500). Data provided by USGS.

100-mm length group

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300

Downstream of IntakeUpstream of Intake

Figure 2. Length frequency histogram of Pallid Sturgeon captured downstream (black bars) and upstream (grey bars) of Intake Diversion Dam in the Yellowstone River during 2017 fall sampling efforts.

2013 2014 2015 2016 2017

S-Q Q-P P-M M-T T

Figure 3. Incremental relative stock density (RSD) for pallid sturgeon captured during fall population monitoring efforts 2013-2017 in the Yellowstone River. Length categories determined using the methods proposed by Shuman et al. (2006).

Capture Year

2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

pallids stockedpallid/kmpallids/hr

Figure 4. Yellowstone River catch per unit effort (fish per kilometer and fish per hour) and stocking history for Pallid Sturgeon in the Yellowstone River and Missouri River below Ft. Peck Dam since 2006. Note: 2017 stocking numbers not included in this figure.

2013 2014 2015 2016 2017

Stock-QualityQuality-Preferred

2013 2014 2015 2016 2017

1.4Preferred-MemorableMemorable-TrophyTrophy

Figure 5. Relative condition factor (Kn) for all Pallid Sturgeon captured with all gear by incremental relative stock density (RSD) length category from 2013-2017 in the Yellowstone River. Length categories determined using the methods proposed by Shuman et al. (2006). Relative condition factor was calculated using the equation in Shuman et al. (2011).

Location Relative to Intake Diversion Dam

Downstream Upstream

PallidShovelnose

Figure 6. Relative abundance of Pallid Sturgeon and Shovelnose Sturgeon captured on the Yellowstone River upstream and downstream of Intake Diversion Dam in 2017.

100-mm length group

300 400 500 600 700 800 900

Figure 7. Length frequency histogram of Pallid Sturgeon captured upstream of Intake Diversion in the Yellowstone River during 2017 fall sampling efforts.

Figure 8. Locations of ground-based, logging telemetry stations deployed on the Yellowstone River (Cartersville, Miles City, Fallon, Gibbs, Hoff, Side Channel Upstream, Intake Dam, Side Channel downstream, Rock, Seven Sisters, Fairview, Yellowstone confluence) and Missouri River (Milk River confluence, Wolf Point, Culbertson, Missouri confluence), and tributaries (Powder River, Milk River) during 2017.

2017AnnualReport

PallidSturgeonPopulationAssessmentandAssociatedFishCommunityMonitoringfortheMissouriRiver:Segments5and6

LandonL.Pierce,DanielA.James,andDylanA.Turner

UnitedStatesFishandWildlifeService

GreatPlainsFishandWildlifeConservationOffice

FundedbyU.S.ArmyCorpsofEngineers–MissouriRiverRecoveryProgram

Summary

PallidsturgeonScaphirhynchusalbusandtheassociatedfishcommunityweresampledintheunchannelizedMissouriRiverdownstreamofFortRandallDam,SD,totheheadwatersofLewisandClarkLake,NE-SD,[i.e.,Segments5and6;formerlyRecoveryPriorityManagementArea3(RPMA3)]during2017usingstandardizedPallidSturgeonPopulationAssessmentProgram(PSPAP)protocols.

PropagationandstockingeffortsaremaintainingthepallidsturgeonpopulationinSegments5and6.Allpallidsturgeoncaught(n=42)during2017wereofhatcheryorigin.Todate,noconfirmedwildpallidsturgeon,excludingtranslocatedindividuals,havebeencaughtinSegments5and6duringPSPAPsampling.Pallidsturgeonfrom15ofthe18yearclassesstockedinSegments5and6werecaughtduring2017.Relativeabundanceestimatesofpallidsturgeonin2017weregenerallylowerthanpreviousyearsforgillnets,trammelnetandottertrawl,butwereintermediatefortrotline.Meanconditionofstock-,quality-,andpreferred–lengthclasses(0.89-0.91)wassimilar(Δ≤±0.05)to2016,butconditionofmemorable-lengthfishin2017(0.85)waslowerthanin2016(0.94).Multipleyearclasses(e.g.,2001-2009)haveshownlittlegrowthinmeanlengthinrecentyearsastheyapproach700mmFL.

ShovelnosesturgeonS.platorynchus,bluesuckerCycleptuselongatus,andsaugerSandercanadensepopulationsappeartobedeclininginSegments5and6duetolowrecruitment.Fewshovelnosesturgeon<550mmoccurredinoursampling,suggestingalackofnaturalreproductionorrecruitment.Similarly,wetypicallyonlycatchafew,ifany,adultbluesuckerannually.Finally,fewsmallsauger(i.e.,<100mm)havebeencapturedsince2013,suggestingnaturalrecruitmentmaybeanissueforthispopulation.

SturgeonchubMacrhybopsisgelida,shoalchubM.aestivalis,andsicklefinchubM.meekioccuratlowrelativeabundancesorareabsentfromSegments5and6.Onlytwosturgeonchub(collectedin2012)havebeencaughtduring15yearsofmonitoring.SicklefinchubandshoalchubhavenotbeencaughtduringPSPAPsamplinginSegments5and6.

BrassyminnowHybognathushankinsoni,plainsminnowH.placitus,andWesternsilveryminnowH.argyritisaretypicallyrareinSegments5and6.In2017,relativeabundanceofbrassyminnowsreturnedtothelowlevelsobservedinmostpreviousyearsfollowingexceptionallyhighrelativeabundancein2016.

ThesandshinerNotropisstramineuspopulationappearsstableinSegments5and6,butrelativeabundanceofsandshinerdecreasedfrom2016to2017.SandshinersareprimarilycapturedinSegment6(i.e.,downstreamfromtheNiobraraRiverconfluence).

Atotalof4,159fishcomprisedof41speciesandonehybridwerecaughtin2017.Wecaughtatleast50individualsof11non-targetspecies:spotfinshinerCyprinellaspiloptera(n=2,299),bluegillLepomismacrochirus(n=392),bluntnoseminnowPimephalesnotatus(n=184),emeraldshinerNotropisatherinoides(n=140),channelcatfishIctaluruspunctatus(n=139),gizzardshadDorosomacepedianum(n=122)rivercarpsuckerCarpiodescarpio(n=101),greensunfishL.cyanellus(n=56),smallmouthbassMicropterusdolomieu(n=66),shortheadredhorseMoxostomamacrolepidotum(n=70),andshortnosegarLepisosteusplatostomus(n=74).Finally,wecaught24falsemapturtlesGraptemyspseudogeographica.

Migrations,Aggregations,andSpawningofPallidSturgeonintheYellowstoneRiverduring2017

PatrickJBraaten,U.S.GeologicalSurvey,ColumbiaEnvironmentalResearchCenter,FortPeckProjectOffice,FortPeck,Montana59223;email:pbraaten@usgs.gov

Background

TheupperMissouriRiverbasinisinhabitedbyanextantstockof100–125(Jageretal.2008)reproductivelyactivewildpallidsturgeonScaphirhynchusalbus.Thestockisinastateofcompleterecruitmentfailureorsevererecruitmentlimitationasevidencedbythelackofsmallandyoungfishthroughthepastseveraldecades(USFWS2007;Braatenandothers,2015a).Owingtothelackofrecruitment,thewildstockhasbeensupplementedalmostannuallysincethelate1990swithplantsofhatchery–originpallidsturgeon(HOPS)producedfromlocalwildbroodstock.WithintheupperMissouriRiverbasin,pallidsturgeonmigrationandspawningoccursinriversofvaryinganthropogenicalterations.TheYellowstoneRivermaintainsmostlynaturalhydrologicandthermalregimes,butisfragmentedbyirrigationdiversiondams.TheMissouriRiverbetweenFortPeckDamandtheYellowstoneRiverconfluenceishydrologicallyandthermallyaltered.Althoughgenerallyviewedasalarge–riverinhabitant(BaileyandCross,1954),pallidsturgeonalsohaveaccesstomultipletributarieswithintheupperbasinhydrosystem.

Lackingdetailedinformationonpallidsturgeonreproductionwhenthespecieswaslistedasendangeredin1990(USFWS,1993)andextendingintotheearly2000s(USFWS2000;2003),substantialknowledgehasaccruedregardingfundamental–yetcritical–attributesofpallidsturgeonreproductiveecology.Inrecentyears,muchfocusonpallidsturgeonreproductionhasoccurredinthevariedhabitattemplateoftheupperMissouriRiverbasin.Withinthemostlynatural–stateYellowstoneRiver,reproductivebehaviorandecologyhavebeendiscernedwithregardstospatialextentandtemporalaspectsofpre–spawnmigrations,pre–spawnbehaviorwherepersistenceofmaleaggregationsatoneormorelocationsdefinespawningpatches,spawningverification,andquantifyinghydraulicelements(forexample,depth,velocity,substrate)atspawningpatches(Fullerandothers,2008;Braatenandothers,2015b;DeLonayandothers2014,2016a,2016b,2016c;DeLonayandothers,inrevision).BeyondverifyingthatspawningoccursannuallyundermostlynaturalenvironmentalconditionscharacteristicoftheYellowstoneRiver,researchtodatehasalsoidentifiedthatspawningpatchesandassociatedhydraulicelementsareatleastpartiallyfunctionaltofacilitatesuccessfulincubationandhatchofembryosbasedoncollectionsofdispersingpallidsturgeonfreeembryos.

AnnualtrendsinpallidsturgeonreproductiveactivitycentermostheavilyinthelowerYellowstoneRiver;however,departuresfromtrendshavebeenobservedintheupstreamreachesoftheYellowstoneRiver,andalthoughlimitedinoccurrencetodate,thesedepartureslikelyinvolveacombinationofelementsincludingIntakeDam,dischargeinthemainstemandtributaries,andmigrationalmotivationinpallidsturgeon.Forexample,themajorityofwildadultpallidsturgeontypicallyexhibitshort–distancepre–spawnmigrationsandremainlocalizedinthelowerYellowstoneRiver.Inmostyears,about12–16percentofthetelemeteredwildadultsmigratetotheupperreaches

wheremigrationterminatesatIntakeDam(RM72.8;DeLonayandothers2014,2016a,2016b,2016c).UnderelevateddischargeintheYellowstoneRiver(forexample,39,000ft3/sandhigher),anaturalhigh–flowsidechannel(hereafterHFSC)aroundIntakeDamflowssufficientlytoprovideconditionsenablingpallidsturgeonpassageandaccesstoreachesupstreamfromIntakeDam(DeLonayandothers2016c).IfindividualsfindtheentrancetotheHFSCandaremotivatedtomoveupstream,migrationsmaypersisttotheupperreachesoftheYellowstoneRiver.MigrationspersistingintothePowderRiver(confluencelocatedatYellowstoneRiverRM150)duringelevateddischargeinthissystemweredocumentedforonegravidfemaleandtwomalesin2014,andspawningmostlikelyoccurredinthePowderRiver(DeLonayandothers2016c).Thus,whereasreproductiveactivitiesforthemajorityofwildpallidsturgeonarecenteredinmainstemofthelowerYellowstoneRiver,thePowderRivermayalsofunctionasasuitablespawninglocationconditionaluponpassagethroughthereachimpactedbyIntakeDam,persistentupstreammigration,andsuitabledischargeconditionsinthePowderRiver.

Contrastingwiththenatural–stateYellowstoneRiver,pallidsturgeonmigrationsandreproductiveactivityintheflow–andthermally–alteredMissouriRiverdownstreamfromFortPeckDamarehighlyvariableamongyears.Pre–spawnmigrationsanduseoftheMissouriRiverbywildadultsmaybelowinsomeyears(forexample,in2012,2014,2015);whereas,inotheryears(forexample,2011,2013,2016),30percentormoreoftelemeteredwildpallidsturgeonwithintheMissouri–YellowstonehydrosystemmaymigrateintotheMissouriRiverduringtheMaythroughJunepre–spawntimeframe(DeLonayandothers2014,2016a,2016b,2016c;DeLonayandothers,inrevision).Withinthisalteredenvironment,itishypothesizedthatelevateddischargefromtheMilkRiver,thedam,orincombinationmaypromoteincreasedutilizationoftheMissouriRiverdownstreamfromFortPeck.Aggregationsofmalepallidsturgeonhavebeendetectedperiodically,butifpresent,tendtoincludefewermalesthanobservedforaggregationsintheYellowstoneRiver.SpawningbypallidsturgeonintheMissouriRiverhasbeenverifiedonasingleoccasion,asevidencedduringtheexceptionallyelevatedflowconditionsin2011whenafreeembryowascaptured(DeLonayandothers2014).Asatributarycontributingwarm,turbidwatertodam–releaseflows,theMilkRivermayperiodicallybeusedbymalesandreproductivefemalepallidsturgeon(forexamplein2013;DeLonayandothers2016b);however,spawninginthistributaryhasnotbeendetected.

Researchin2017expandedonearlierinvestigationsofpallidsturgeonreproductiveecologyintheUpperMissouriRiverbasin.ProgresssummarizedinthisreportfocusesonpallidsturgeonintheYellowstoneRiverasprogressontheMissouriRiverissummarizedunderaseparatereportbyMontanaFish,WildlifeandParks(MTFWP).Theobjectivesincluded:1)assessspatiotemporalattributesofpallidsturgeonpre–spawnmigrations,2)identifythelocation(s)andtimingofspawningevents,and3)verifyfunctionalityofspawninghabitatsbasedoncapturesofpallidsturgeonfreeembryosandlarvae.Inpreviousyears,theUSGSandMTFWPwereprimarycollaboratorstoaccomplishprojectobjectives.In2017,theBureauofReclamation(BOR)initiatedaprojectatIntakeDamthatinvolvedthesamepopulationoftelemeteredwildpallidsturgeonandHOPSasexaminedinthepresentstudy.Inthisproject,theBORimplementedatranslocationstudy,wherebytelemeteredwildadultsandHOPSmigratingtoIntakeDamwerecaptured,andtranslocatedupstreamfromthedamtoensurepassageandfacilitatepotentialmigrationstoupstreamareasoftheYellowstoneRiver.Thus,collaborationsin

2017alsoincludedtheBORastheirtelemetryandrelocationdataexpandeddatasetsforanimprovedspatialunderstandingpallidsturgeonintheYellowstoneRiversystem.

Methods

Theresearchpopulationoftelemeteredpallidsturgeonassessedin2017included57wildadultsandgreaterthan130HOPSofknown,suspected,andunknownsexorreproductivestatus.Additionalwildpallidsturgeonwerepresentinthesystem,butsomewerecapturedandtakentothehatcheryforpropagationin2017andotherswereinfrequentlydetectedduringtelemetrywork.AdditionalHOPSweretransmitteredthroughsummerandfall2017,andcollectively,nearly180HOPScarriedtransmittersbylatefall.Fourwildfemalepallidsturgeoncomprisedthecandidatelistofpotentialspawnersbasedonpre–spawnreproductiveassessmentsofbloodhormones(testosterone,T;estradiol,E2;eggpolarityindex,PI)andweight.Thespawn–candidatefemalesincludedcode43(captureandimplantedon5/3/17,weight=27.5kg,T=84.54ng/ml,E2=4.73ng/ml,PI=0.096),code127(captureandimplantedon5/2/17,weight=25.0kg,T=69.17ng/ml,E2=5.73ng/ml,PI=0.083),andcode87(capture5/11/17,weight=22.5kg,T=46.18ng/ml,E2=3.31ng/ml).Thefourthcandidatefemale(code41)wasnotassessedpre-spawnashertransmitterwasdifficulttodetectandshecouldnotbecaptured(seeProgresssectionbelow),butbasedonherpast2-yearspawnperiodicity(2013,2015),itwasanticipatedthatcode41wouldbeaspawn-candidatein2017.

RadiotelemetryincludingmanualtrackingbyboatanddeploymentofautomatedtelemetrygroundstationswasinitiatedinApril.Pallidsturgeonrelocationpointsandenvironmentalattributesobtainedduringmanualtrackingwererecordedonahighlycustomizedmobilemappingandelectronicdatacollectionapplication.AutomatedtelemetrygroundstationsweredeployedatmultiplelocationsintheYellowstoneRiverincludingneartheconfluence(RM0.75),atRM7.0,RM39.0,RM61.5,IntakeDam(RM72.8),RM99.0,RM115.0,andatthePowderRiverconfluence(RM147.0).TelemetrygroundstationswerealsodeployedwithintheHFSCadjacenttoIntakeDamnearthedownstream(RM71.0)andupstream(RM75.0)connectionstothemainstemriver.Inaddition,telemetrygroundstationsweredeployedintheMissouriRiverandMilkRiverasdescribedintheMTFWPreport.Groundstationdetectionscomplementedwithmanualtrackingrelocationsprovidedacontinuousassessmentofmigrationsandmovementswithinandamongrivers.

SamplingforpallidsturgeonearlylifestageswasconductedinthelowerYellowstoneRiverandPowderRivertoverifyhatchanddrift–entryoffreeembryosandpotentiallyextendeddispersaloflarvae.SamplingintheYellowstoneRiveroccurredJune7–27primarilybetweenRM3.2–5.6,andinthePowderRiver,samplingwasconductedduringJune12–19.Samplingforpallidsturgeonfreeembryosandlarvaewasconductedusing3.0-mlongtaperedrectangularnets(1.0mmmesh)affixedtorectangularframes(0.75-mwidth,0.5-mheight;seeBraatenandothers,2010).Pairednetsweresimultaneouslydeployedfromtheportandstarboardsidesoftheboatbow,andfishedinthelower0.5–mofthewatercolumnadjacenttotheriverbed.Asoundingweightorpaireddownriggerweightswereattachedtothenetframetomaintainnetcontactwiththeriverbed.Samplecontentswereflushedfromthenetandterminalcollectingcup,transferredtoblackpans,andAcipenseriformes(shovelnosesturgeon,pallidsturgeon,paddlefish)freeembryosandlarvaewerelive–extractedfrom

thedetritus.Specimenswereimmediatelypreservedinvialscontaining95percentnon–denaturedethanol.Inthelaboratory,preservedspecimensweretentativelyidentifiedasScaphirhynchussp.,paddlefish,orunknown(thatis,damagedbeyonddefinitiverecognitionbecauseofsmashedbodiesormissingbodyparts)basedonmorphometricandmeristiccharacters,measured,andphotographed.PreservedAcipenseriformesweresenttoDr.EdHeist(SouthernIllinoisUniversity)forgeneticanalysis(Eichelbergerandothers,2014)todifferentiatespecimensasshovelnosesturgeon,pallidsturgeonorpaddlefish.

Progress

HydrologicandThermalRegime

FlowconditionsintheYellowstoneRiverandtributariestendedhigherin2017thanlong–termaverages.AveragedischargeintheYellowstoneRiverrecordedatSidney,Montana(USGSgagenumber06329500)duringApril(19,157ft3/s),May(34,039ft3/s),andJune(44,357ft3/s)was180,186,and115percent,respectively,oflong-termconditions(1911–2016)forthesemonths.DischargeatSidneyinitiallypeakedonMay17(45,800ft3/s),andtheseasonalmaximaoccurredonJune10(57,300ft3/s;Braaten_Figure1).ElevateddischargesinthelowerYellowstoneRiverwerepartiallyattributedtoelevateddamreleasesintheBighornRiversystem(confluenceatRM295;USGSgagenumber06294500)asflowsaveraged11,550ft3/sinApril(311percentofnormal),14,770ft3/sinMay(327percentofnormal),and11,840ft3/sinJune(192percentofnormal).DischargeinthePowderRiver(Braaten_Figure1)wasalsogreaterthanlong-termconditionsasflowsinApril(mean=898ft3/s),May(2,479ft3/s),andJune(mean=1,969ft3/s)were126,205,and121percent,respectively,oflong-termrecords(1939–2017;USGSgagenumber06326500).DischargeinthePowderRiverwasgreatestinmid-May(May16–21,2,930–3,130ft3/s),declinedfromlate-MaythroughearlyJune,thenincreasedonJune16(2,860ft3/s)beforedecliningintolateJune.WatertemperatureintheYellowstoneRiver(Braaten_Figure1)progressivelywarmedfromApril25(9.2oC)toMay14(17.8oC),butwithincreasingdischarge,temperaturedeclinedto14.0oCbyMay21.Watertemperatureincreasedto20.1oCbyJune10,thendeclinedto17.7oConJune18.WatertemperatureremainedrelativelycoolduringJune19–June25(18.3–19.2oC,mean=18.7oC)beforeincreasingtosummermaximainJuly.

PallidSturgeonUseoftheYellowstoneRiver

PallidsturgeoninitiatedmovingintotheYellowstoneRiverbyearlyApril,andbyearlyMay,greaterthan70percentoftelemeteredwildadultswerepresentintheYellowstoneRiver(Braaten_Figure2).PallidsturgeoncontinuedmovingintotheYellowstoneRiverduringMay,andbyJune1,91%ofthetelemeteredresearchpopulationofwildadultsutilizedtheYellowstoneRiversystem.UsediminishedgraduallythroughJune22(greaterthan70%remained).DuringlateJuneandearlyJuly,pallidsturgeoncontinuedemigratingfromtheYellowstoneRiverasdischargedeclined.

MigrationstoandUpstreamofIntakeDam

ManualtelemetrycomplementedwithdetectionsfromloggingstationsidentifiedmigrationsofwildpallidsturgeonandHOPStoIntakeDam,andthroughtheHFSCadjacenttothedam.Fivewildmale

pallidsturgeon(8.8%ofthetelemeteredwildpopulation;codes11,49,57,61,83)weredetecteddownstreamfromIntakeDam;theearliestarrivaloccurredonMay6-8(mainstemdischarge=22,900–23,700ft3/s;Braaten_Figure3;Braaten_Table1).Atotalof14HOPSwerealsodetectedatIntakeDam(Braaten_Table1).EarliestdetectionsforHOPSatIntakeDamoccurredinearlyApril(code91,April3-9;code72,April7-11;mainstemdischarge16,800–18,200ft3/s).BothoftheseHOPSwerealsodetectedbelowthedaminOctober2016.AlthoughseveralHOPSwereimplantedwithtransmittersincloseproximitytoIntakeDamandeventuallyprogressedashort–distanceupstreamtothedam,someHOPSalsoexhibitedsubstantialmigrationsthatterminatedatIntakeDam.Forexample,HOPSmalecode62(sexdeterminedbyvisualobservationoftestesduringsurgeryandelevatedT=217.6ng/ml)wasimplantedonMay3atRM6.6oftheYellowstoneRiver,andmigratedupstreamtoIntakewhereinitiallydetectedonMay13.AsecondHOPSalsoexhibitedalong-distancemigrationasmalecode98(T=94.63ng/ml)wasimplantedonMay16atRM1,710.5oftheMissouriRiver,andwasinitiallydetectedatIntakeonAugust18.

WhereastheupstreammigrationextentforseveralpallidsturgeonterminatedatIntakeDam,fourpallidsturgeon(wildmalecodes49,61;HOPScodes66,160)swamthroughtheHFSCtocontinueupstreammigrations(Braaten_Table1).TheearliestmigrationthroughtheHFSCoccurredonMay15–16forHOPScode160whenmainstemdischargewas40,000–44,600ft3/s.DuringJune6–13,thethreeotherpallidsturgeonmovedthroughtheHFSCatdischargesrangingfrom52,200–57,300ft3/s.Twootherpallidsturgeon(HOPScodes154,155)weredetectedbytheHFSCdownstreamloggingstationandmanuallyrelocatedwithinthesidechannelonseveraldates,butdidnotswimthroughtheentirelengthoftheHFSC.

ThroughthecombinationoftranslocationofpallidsturgeonimplementedbytheBORandvolitionalswimmingthroughtheHFSC,migrationsforninepallidsturgeonpersistedupstreamfromIntakeDam(Braaten_Table1).Migrationsforsixpallidsturgeon(wildmalescodes49,61;HOPScodes54,66,160,169)extendedtoRM75.0–123.4oftheYellowstoneRiver.UpstreammigrationsforthreeotherpallidsturgeonpersistedthroughtheYellowstoneRiver,andintothePowderRiver(Braaten_Figure3;Braaten_Table1).AftertranslocationonMay8,wildpallidsturgeonmalecode83wasdetectedatYellowstoneRiverRM92.6onMay10andatthePowderRiverconfluenceloggingstationonMay15.Followinganinitiallyincreasing(May16–21;2,930–3,130ft3/s)thendecreasinghydrograph(May22–June1;2,120–2,820ft3/s),code83waslocatedonJune1atPowderRiverRM89.9duringanaerialsurveyconductedbyMTFWP.Code83wassubsequentlydetectedinthePowderRiveratRM80.4onJune9andatthePowderRiverconfluenceloggingstationonJune19,swamdownstreambetweenYellowstoneRiverRM99.0andIntakeDamonJune20,wasdetectedatRM63.4andRM39.0onJune21andJune22,respectively,andrelocatedatRM7.0onJune23.Code91(HOPS)wastranslocatedonMay10,anddetectedatthePowderRiverconfluencegroundstationonMay20.ThisindividualpersistedmovingupthePowderRiver,beingrelocatedatRM11.3onMay23,RM16.4–17.3onMay25,andaeriallydetectedbyMTFWPatPowderRiverRM65.9onJune1andRM97.0onJune9.Upstreamprogressionofcode91inthePowderRiveroccurredduringperiodsofdeclining(May21–June2;2,040–3,130ft3/s)andincreasingflows(June3–June9;2,090–2,450ft3/s).Thefinalrelocationofcode91occurredonJuly29atRM95.5,andthetransmitterandremainsofthefishwere

found.Wildpallidsturgeonmalecode11wasthethirdknownpallidsturgeontoutilizethePowderRiver.AftertranslocationonMay14,code11movedupstreamandwasdetectedatthePowderRiverconfluenceloggingstationonMay22.UtilizationofthePowderRiverbycode11wasverifiedbasedonrelocationsforMay23(RM9.4),May25(RM26.2),andaerialdetectionsbyMTFWPonJune1(RM88.1)andJune9(RM4.0).DuringtheMay23–June1upstreammigrationforcode11,dischargewasprimarilydeclininginthePowderRiver(2,120–2,700ft3/s).Subsequentrelocationsforcode11includedthePowderRiverloggingstationonJune12,YellowstoneRiverRM107.8onJune13,detectionsatRM99.0,IntakeDamandRM39.0onJune14,andthelowerYellowstoneRiverthroughlateJune.

MaleAggregationsandPallidSturgeonSpawningChronology

TransitoryandpersistentaggregationsofwildmalepallidsturgeonandHOPS(knownmaleandunknownsex)wereobservedinthelowerYellowstoneRiverduring2017(Braaten_Figure4).DuringMayandearlyJune,lowtolargenumbersofpallidsturgeonwerenotedinseverallocationswithlargeearly–seasonaggregationsoccurringonMay10atRM6.5(10fish),May16atRM2.6(12fish),May23atRM2.5(8fish),May31atRM6.3(9fish),May31atRM2.2(10fish),June1atRM6.1(14fish),andJune2atRM6.0(17fish);however,theseaggregationsearlyintheseasonweretransitoryandnotpersistentformultipledays.FromJune8throughJune22,persistentandfrequentlylargeaggregations(greaterthan8fish)werepresentbetweenRM5.4–6.1.AsecondaryaggregationalsooccurredbetweenRM4.7–4.8duringJune15–18,butthisaggregationdisbandedasmalesandHOPSre-aggregatedattheRM5.4–6.1aggregationsite.

Pallidsturgeonfemalecode43wasthelargest(27.5kg)spawn–candidatefemaleintheresearchpopulationfor2017.ThisfemaleremainedmostlylocalizedinthelowerYellowstoneRiver,exhibitinglimitedup-anddownstreampre–spawnmigrationswherethemaximumobservedupstreamlocationoccurredatRM11.2onMay16(Braaten_Figure5).FromJune1–17,minimalmovementswereobservedforcode43asshewasdetectedonlybetweenRM5.6–7.1.OnthemorningofJune18(~10:00AM),code43waslocatedatRM5.9intheareawhereseveralmaleshadbeenaggregatedinpreviousdays;however,onlyoneotherfish(HOPScode157)wasdetectedincloseproximity.Atabout3:00PMonJune18,femalecode43andmales(wildfishcodes73,82,90,193;HOPScode62)wereaggregatedatRM5.8insuspectedspawningactivity.Throughabout5:30PM,code43andthemales(withadditionofwildfishcode77)remainedatRM5.5–6.0.OnthemorningofJune19,relocationsduring9:50AM–11:15AMidentifiedmultiplemales(wildcodes10,11,48,57,59,73,77,82,193;HOPScodes132,157)remainedaggregatedatRM5.7–5.9;however,femalecode43wasabsentfromtheaggregation.Code43waslocateddownstreamatRM4.6(10:40AM)wheresheexhibitedminimalmovement(RM4.5–4.6)throughlateafternoon.Suspectingthatspawningwascompletedbasedonherdeparturefromthemaleaggregation(asisthetypicalbehavior),code43wouldhavebeentargetedforimmediatecapturetoverifyspawning.However,asecondspawningeventinvolvingfemalecode87hadbeeninitiated(seebelow),andcrewsfocusedeffortsoncode87fortheday.Femalecode43wascapturedonJune20atRM4.7;sheweighed4.0kgless(23.5kg)thanpre–spawn(27.5kg),indicativeofa14.5%weightlossduetoeggdeposition.Bloodsamplesobtaineduponcapturebutanalyzedlateralsoindicatedpost–spawnhormonelevels(T=0.83ng/ml,E2=not–detectible).Basedonthese

results,thespawningchronologyforcode43likelyincludedthefollowingscenario:spawningwasinitiatedonJune18between10:00AM(nomaleaggregation)and3:00PM(withmaleaggregation)aroundRM5.8,persistedatRM5.4–6.0,andconcludedpriorto9:50AMonJune19(code43absent).Environmentalconditionsduringthecode43spawningeventincludedameandischargeof38,600ft3/s(June18)and36,700ft3/s(June19),andmeantemperature17.7oC(June18)and18.3oC(June19).

Femalecode87wasasecondspawn–candidatefor2017.ThisfemaleexhibitedaprogressiveupstreammigrationduringearlyMaythatpersistedtoRM29.4onMay11whenshewascapturedandassessed(weight=22.5kg;Braaten_Figure5).Followingthismaximumupstreampre–spawnmigration,code87movedupstreamanddownstreamthroughthelowerYellowstoneRiverduringmid–Maythroughmid–JunewithanupstreammigrationtoRM13.8onJune8.OnJune16,alargeaggregationofmales(forexample,wildfishcodes32,48,59,75,77,82,193,196;HOPScode128)waspresentatRM4.7–4.8duringthemorningandafternoon;however,femalecode87swamthroughthisaggregationandpersistedmovingupstream.Multiplepallidsturgeon(forexample,wildfishcodes10,11,27,42,73;HOPScodes100,132,157)werealsodetectedatRM5.4–6.1onJune16,butcode87alsomovedupstreampastthesefishasshewasfoundatRM16.6onJune17.OnthemorningofJune18,code43wasdetectedatRM11.0movingdownstream,andbyevening(6:25PM)waslocatedatRM5.8.OnthemorningofJune19,code87wasinitiallylocatedatRM5.3(10:22AM),butbyaboutnoon,shehadmovedupstreamtoRM6.0pastthemaleaggregation(wildcodes10,11,48,57,59,73,77,82,193;HOPScodes132,157)aggregatedatRM5.7–5.9.Fromabout2:40PMthrough8:35PMonJune19,code87andmultiplemales(codes10,11,48,57,59,73,77,82,193,196;HOPScode62)wereengagedinpresumedspawningactivityatRM5.4–6.0ascrewsrecordedmultiplepointsonthefishinthisareaoftheriver.CrewsreturnedonJune20,andalthoughmultiplemaleswerepresentatRM5.3–6.0(codes10,11,48,57,59,73,77,82,196;HOPScode100),femalecode87wasabsentfromtheaggregationsiteandwasrelocatedatRM4.3(11:44AM).Code87wasre–capturedonJune20atRM3.7andweighed19.0kg,3.5kglessthanherpre-spawnweight(15.6%weightlossduetoeggdeposition).Abloodsampleobtainedatthetimeofcaptureandanalyzedlateralsoverifiedspawningthroughchangesinreproductivehormones(T=4.31ng/ml,E2=not–detectible).Thespawningchronologyforfemalecode87likelyincludedthefollowingscenario:initiationofspawningatRM5.5onJune19betweenaboutnoonand2:40PM(whenshewasfirstdetectedwithmalegroup),persistentspawningactivityatRM5.4–6.0throughabout8:35PM(basedonnumerousmale–femalerelocations),andspawncompletionby11:44AMonJune20.AveragedischargeduringJune19andJune20was36,700ft3/sand40,200ft3/s,respectively,andwatertemperatureaveraged18.3oCand18.8oCfortherespectivedates.

Femalecode41wasasuspectedspawn–candidatepallidsturgeonfor2017.However,thisfemalewasnotcapturedforpre–spawnassessmentsasthetransmittersignalwasdifficulttodetectandpinpointintheriverchannelforcapture.Whendetectedpre–spawn,nettingeffortswereunsuccessful.Uponcapturelaterintheseason(seebelow),itwasobservedthatthetransmitterantennaewasbrokenofflikelycontributingtolowdetectabilityforthisfish.Basedonthe2–yearspawningcycleevidentfromearlierstudies(forexample,spawnerin2013,2015),code41remainedatargetfemaleforthe2017spawningwork,andcrewstriedtomaintaincontactwithandrelocatethis

femaleduringtrackingruns.Relocationsforcode41indicatedthisfishremainedlocalizedinthelowerYellowstoneRiverwherethegreatestupstreamdetection(RM7.6)occurredonMay16(Braaten_Figure5).FromJune7–14,code41exhibitedlittlemovementandwascontactedinthelowerYellowstoneRiverbetweenRM0.1–0.3.RelativelyconsistentcontactwasobtainedduringJune19–June23ascode41movedintodetectiblelocations.OnJune19,code41wasrelocatedmultipletimesatRM3.1–3.2,butonlyoneotherfish(HOPScode25)wasnearby.Code41wasrelocatedslightlyupstreamonJune20(RM3.9),butnomalepallidsturgeonwereincloseproximity.OnJune21,crewsrelocatedandmaintainedsurveillanceoncode41atRM4.1–4.2asthefemalehadmovedslightlyupstream.Twopallidsturgeon(wildmalecode75;HOPScode127)werelocatednearbycode41.At11:00AMonthemorningofJune22,code41wasinitiallylocatedatRM3.9inasmallaggregationincludingwildmales(codes59,75,77)andHOPScode25.Crewsmaintainedsurveillanceoncode41duringtheday,andidentifiedthatwildmalecode196andHOPScodes62and127werealsointhearea.Byabout4:30PMonJune22,code41hadmoveddownstreamtoRM3.4andtwowildmales(codes59,196)werecloselyassociatedwithher.Suspectingthatspawningwascompletedornearlycompletedbasedonherdownstreammovement,code41wastargetedforcapture.Nettingattemptswereunsuccessfulforcode41asthefemalecontinuedtomovedownstream,andultimatelysettledinanoutsidebendlocationcontainingemergentandsubmergedtrees;however,wildmalecode196whowascloselyassociatedwithherwascapturedduringnettingandobservedtobereleasingmilt.Code41wascapturedonJune23,weighed25.0kg,andbasedonthelackofeggsinthebodycavity,wasdeterminedaspost–spawn.Abloodsampleobtainedatcaptureandanalyzedlaterindicatednon-detectiblelevelsofTandE2.Additionally,asampleofovariantissuewasobtainedforanalysis.Histologicalanalysisoftheovariantissueindicatedpost–ovulatoryfollicles,indicativeofrecentspawning(Dr.MollyWebb,USFWS,pers.comm.).EnvironmentalconditionsduringtheJune21–22suspectedspawningeventforcode41includedameandischargeof40,350ft3/sandmeanwatertemperatureof19.2oC.

Femalecode127wasthefourthspawn–candidatepallidsturgeonfor2017.AfterinitialcaptureandtransmitterimplantationonMay2,thisfemaleremainedrelativelylocalizedinthelowerYellowstoneRiverduringMay(Braaten_Figure5)withhermostupstreamrelocationpointoccurringatRM11.1onMay12.OnMay31at7:11PM,code127andseveralwildmalepallidsturgeon(codes8,17,23,27,77,81,82,89,91,93)wereaggregatedatRM2.2.Spawningwasnotsuspectedonthisearlydateaswatertemperaturewascool(17.3oCat7:11PM)andhadbeencoolinprecedingdays(May29mean=15.4oC,May30mean=15.7oC).Furthermore,basedonearlieryearsofstudy,itisnotuncommonforafemaletotemporarilyaggregatewithmalesearlyintheseasonpriortocontinuingmigratorybehavior.Code127wasrelocatedatRM2.4onJune1,butonlytwowildmales(codes17,91)wereintheneararea.OnJune2,code127wasinthesamegeneralarea(RM2.3at11:50AM)withfemalecode87andwildmalecode17inthearea.Code127wasrelocatedinasimilarlocationonJune6(RM2.4),butotherpallidsturgeonwerelackingfromthearea.DespitetrackinginthelowerYellowstoneRiveronJune7–8,code127wasnotrelocated.TrackinginsubsequentdayswasexpandedtotheMissouriRiverdownstreamfromtheYellowstoneRiverconfluenceinsearchofcode127,andthefemalewasrelocatedatRM1,580.0–1,580.6fromJune9–11.Itwasanticipatedthatcode127wouldmovebackintotheYellowstoneRiveraspartofherpre–spawnmigration;however,

thefemalewasnotfoundagainuntilJuly19whenrelocatedintheMissouriRiveratRM1,567.4(depth=7.6meters,23.8oC).Code127wasnotrecapturedtoverifyifspawninghad/hadnotoccurred.

VerificationofHatchandDispersalofPallidSturgeonFreeEmbryosandLarvae

Samplingforpallidsturgeoneggs,developingembryos,anddispersingfreeembryosandlarvaewasinitiatedonJune7priortoknownspawningevents,andcontinuedthroughJune27tocoincidewithexpectedincubationandhatchtimelinesfromthefinalspawningeventinvolvingfemalecode41.CollectiveeffortsbetweenUSGSandMTFWPforthelowerYellowstoneRiverincluded477samplesacrossdatesthatresultedin794Acipenseriformeseggsanddevelopingembryos,and1,685Acipenseriformesfreeembryosandlarvae(Braaten_Table2).Nearly48percentoftheeggsanddevelopingembryos,and79percentofthefreeembryosandlarvaewerecollectedfromJune19–27followingtheinitiationofknownspawningeventsintheYellowstoneRiver.SamplingforpotentialpallidsturgeonearlylifestagesinthePowderRiverwasconductedbyMTFWPpersonnelduringJune12–19.Throughthissampling,fiveeggsanddevelopingembryoswerecollectedalongwith35dispersingAcipenseriformesfreeembryosandlarvae.Specimensfrombothriversystemsweremeasuredandtentativelyidentifiedinthelaboratoryaspaddlefish,Scaphirhynchussp.,orunknown(duetomashedbodies,broken,tornormissingportionsofbodies,etc.).Specimensareintheprocessofgenetictestingtodifferentiateindividualsaspaddlefish,shovelnosesturgeonorpallidsturgeonfollowingmethodsofEichelbergerandothers(2014).

Discussion

PallidsturgeonintheupperMissouriRiverbasinhavetheabilitytousethenatural–stateYellowstoneRiverandflow–andtemperature–alteredMissouriRiverforpre–spawnmigrations.In2017,telemeteredwildadultsprimarilyusedtheYellowstoneRiveraspre–spawnmigrationsintotheriverwereinitiatedinApril,andmaximumuse(91percent)wasattainedbyearlyJune.Workduring2012–2016alsodocumentedprimaryuseoftheYellowstoneRiverwhere83–93percentofthetelemeteredwildpallidsturgeonmovedintotheriverbylateMayandearlyJune(DeLonayandothers,2016a,2016b,2016c;DeLonayandothers,inrevision).Adivergencefromthisgeneraltrendwasobservedduringextremelyelevatedflowconditionsin2011whenabout60percentofthewildadultsusedtheYellowstoneRiver,and35–40percentusedtheMissouriRiverdownstreamfromFortPeckDam(DeLonayandothers2014).

AfterenteringandmaintainingresidencyintheYellowstoneRiver,mostwildadultsremainedinthelowerportionsoftheriver;however,pre–spawnmigrationsforfivewildadultpallidsturgeon(about9percentofthetelemeteredresearchpopulation)in2017persistedtoIntakeDamwithinitialarrivaltothedam(malecode83)occurringonMay6–8.Datafrom2012–2016identifiedthatabout12–16percentoftelemeteredadultsweredetectedatIntakeDam,withthegreatestproportion(26percent)detectedatIntakeDamduring2011(DeLonayandothers,2016a,2016b,2016c;DeLonayandothers,inrevision);datesforinitialarrivalofwildpallidsturgeontoIntakeDamduring2011–2016spannedfromearlyApriltomid–May.Althoughseveralyearsofdatacenteredonwildadultshave

providedinferencesonpre–spawnmigrationsextendingtoIntakeDam,informationonmovementsbyanduseoftheYellowstoneRivernearIntakeDamforHOPSisexpandingasthenumberoftelemeteredHOPScontinuestoincrease.Atotalof14HOPSwasdetectedatIntakeDamduringthe2017fieldseason.DetectionsforHOPSspannedfromearlyAprilthroughOctoberlikelyrepresentingacombinationofbehaviorsincludingshort–andlong–distancemigrationsterminatingatthedamandresidencydownstreamfromthedam.Forexample,twoHOPS(codes72,91)hadearlyAprildetectionsatIntakeDamandlikelyrepresentedpallidsturgeonthatover–winteredincloseproximitytothedam.Comparatively,reproductiveHOPSmalecode62wastransmitteredonMay3atRM6.6oftheYellowstoneRiver,migratedupstream,andarrivedatIntakeDamonMay13whereitremainedforafewdays.Asecondreproductivemale(HOPScode98)wastelemeteredonMay16intheMissouriRiverabout130milesupstreamfromtheYellowstoneRiverconfluence.ThisHOPSmoveddownstreamintheMissouriRiver,movedupstreamintheYellowstoneRiver,thenarrivedatIntakeDamonAugust18(nominalmigrationdistance~200miles).Collectively,HOPS(reproductiveandnon–reproductive)areexpressingpotentiallybroad–scalemovementswithinandbetweentheMissouriandYellowstoneRivers,andasevidencedfrom2017,anincreasingnumberofHOPSarebeingdetectedatIntakeDam.

AlthoughIntakeDammayimpedeorcompletelyblockpallidsturgeonmigrationswithinthemainchanneloftheYellowstoneRiver,thenaturalHFSCcircumventingtheIntakereachcanfunctiontoprovidepartiallongitudinalconnectivityduringsometimeperiodsandfacilitatemigrationaccesstoareasupstreamfromIntakeDam.In2017,two(codes49,61)offivewildpallidsturgeonandtwo(codes66,160)of14HOPSdetectednearIntakeDamusedandfullynegotiatedtheHFSCtocontinuemovingupstream.DischargewithintheHFSCwasnotmeasuredondateswhenpassageoccurred,butdischargeinthemainstemriverwas40,000–44,600ft3/sduringtheearliestpassageevent(May15,16)and52,200–57,300ft3/s(forsubsequentpassageevents(June6–13).UseandcompletenegotiationoftheHFSCbypallidsturgeonin2017occurredwithinflowrangesreportedinearlieryears.Forexample,fivewildadultpallidsturgeon(1female,4males)swamthroughtheHFSCin2014whenmainstemdischargewas47,300–68,100ft3/s(DeLonayandothers,2016c),andin2015,passagethroughtheHFSCoccurredforawildadultmalepallidsturgeonatdischargesof39,500–42,300ft3/s(DeLonayandothers,inrevision).Basedonfindingsfromthesepassageevents,hydraulicconditionsinthenaturalHFSCshouldbesuitableforpallidsturgeonpassagewhendischargeinthemainstemriverisabout39,500–68,100ft3/s.However,suitabledischargeandthepresenceofpallidsturgeonintheHFSCcannotensurethatpassagewilloccurasevidencedfortwoHOPS(codes154,155)thatweredetectedinthelowerportion,butneverfullyascendedtheHFSC.Forexample,HOPScode154wasinitiallydetectedintheHFSConMay18–20whendischargewasmoderatelylow(USGSgageatGlendive06327500,37,700–39,500;USGSgageatSidney06329500,38,700–41,600).DespiteexperiencingelevateddischargeslaterwhileintheHFSC,HOPScode154didnotpersistinmigratingupstream.TheHOPScode155alsoexperiencedelevateddischargewhileintheHFSC,butpassagedidnotoccur.

PallidsturgeonthatswamthroughthesidechannelorweretranslocatedaroundIntakeDambyBORpersonnelhadpotentialtocontinuemovingupstream.Resultsfrom2017forbothgroupsofpallidsturgeonarehighlyrelevanttoproposedworkinfutureyears,andaddtoinferencesonmainstemandtributaryusegainedfromearlierstudyyears.First,althoughtranslocationofpallidsturgeonaround

IntakeDamwasmandatedunderReasonableandPrudentMeasure2inthe2016IntakeBiologicalOpinion,therewasmuchuncertaintywiththetechniqueastranslocationhadnotbeenconductedwithpallidsturgeonfromwhichresponsesfollowinghuman–handlingcouldbepredicted.Translocation(alsocommonlyreferredtoascatchandhaul)hadbeenimplementedinlakesturgeonAcipenserfulvescens(McDougalletal.2013)andwhitesturgeonA.transmontanus(Rust2011).Implementedasapilotprojectin2017,translocationwassuccessfulforthetwowildandthreeHOPSascontinuedupstreammigrationoratleastlocalizedresidencynearthetranslocationreleasesitewasobservedforallindividuals;fall–back(immediate,rapiddownstreammovementfollowingtranslocation)didnotoccur.Thus,althoughthe2017samplesizewassmall,resultssuggestthatpallidsturgeontranslocationinfutureyearscanfacilitatecontinuedupstreammigrationsofpallidsturgeonbeyondIntakeDam;however,post–translocationbehavioraldeviationsmayoccurdependingonfishreproductivestate,motivation,andhandlingpractices.Translocationisplannedforcontinuedimplementationin2018.

Second,whereassixpallidsturgeon(2translocated,4free–swimmingmigrantsthroughHFSC)exhibitedmovementsuptoaboutYellowstoneRiverRM123.0,threetranslocatedmalepallidsturgeon(2wild,1HOPS)migratedtoRM149.0(PowderRiverconfluence),andthencontinuedupstreaminthePowderRiverwhereterminalrelocationsoccurredbetweenRM88.1–97.0.UseofthePowderRiverin2017complementsobservationsfrom2014whenareproductivewildfemale(code36)andtwowildmales(codes61,68)usedthePowderRiver(DeLonayandothers,2016c),andspawningoccurredwithinthelower20milesmostlikelyduringJune10–17timeframe.LackingaknownreproductivetelemeteredfemaleinthePowderRiverfromwhichchangesinreproductivestatuscouldbeusedtoverifyspawning,definitivespawninginthePowderRiverduring2017wasnotascertained.Itispossiblethataspawneventinvolvingoneormorenon–transmitteredfemalesandpotentiallyothernon–transmitteredmalescouldhaveoccurredonoraboutJune1whenthetwowildmales(codes11,83)wereaeriallylocatedbyMTFWPneartheirmigrationapex(RM88.1–89.9).However,aJune1spawningdatewouldhavebeenearlybasedonthetimingoftypicalknownspawningevents(forexample,mid–tolate–June).Thevariedmovementbehaviorsforthemalesalsomakesitdifficulttodiscernif,where,andwhenspawningoccurred.Forexample,followingtheJune1apexlocationforcodes11and83,detectionsinthePowderRiveronJune9indicatedthatcode11wasnearRM4.0andcode11wasnearRM80.0,whileHOPScode91maintainedanupstreamtrajectorybeingfoundnearRM97.0.Thevariedmalemovementscouldrepresentdifferentreproductivestates,includingcompletionofspawnandriverexit(forexample,code11)orcontinuedreproductivereadiness(codes83,91).

Resultsfrom2014and2017provideinferencestosuggestthatthePowderRivercanbeamigrationdestinationforpallidsturgeon,conditionalonpassagearoundIntakeDamandpersistentelevatedflowconditionsinthePowderRiver.Resultsalsosuggest,however,thatonlyaportionofthepallidsturgeonupstreamfromIntakeDammayusethePowderRiverinanygivenyear.Forexample,one–thirdofthe9telemeteredpallidsturgeonupstreamfromIntakeDamin2017persistedmigratingintothePowderRiver;percentagesmaychangefromyeartoyeardependingonorigin(forexample,wildversushatchery),reproductivestatus,andmigratorymotivation.Collectively,useofthePowderRiverontheYellowstoneRiverorothertributariessuchastheMilkRiverontheMissouriRiverneedscontinuedevaluationtodeterminetheecologicalvalueofthesesystemstopallidsturgeon;the

progressivelyincreasingnumbersofwildadultsandmaturingHOPSimplantedwithtransmittersprovidetheopportunityfortheseevaluations.

ThetemporaloccurrenceandspatialextentofpallidsturgeonaggregationsinthelowerYellowstoneRiverobservedin2017weremostlyconsistentwithearlierinvestigativeyears.Smallandlargeaggregationscomprisedofwildmales,knownHOPSmales,andunknownsexHOPSwerefoundinthelowerninemilesoftheYellowstoneRiverduringMaythroughearlyJune,butmostearlyseasonaggregationspersistedforonlyafewdays.AfterearlyJune,theprimaryaggregationoccurredatRM5.4–6.1andthisareawaslateridentifiedastheknownprimaryspawninglocationinvolvingreproductivefemalescodes43and87.AsecondaryaggregationofwildmalesandHOPSwasobservedforafewdaysinmid–JuneatRM4.7–4.8,butitisunknownifspawningoccurredwithinthisaggregationasthespawningeventwouldhaveincludednon–telemeteredfemales.Whereasearlierdescriptionsandquantificationsofpallidsturgeonaggregationshavecenteredonwildmales,itisbecomingincreasingevidentthatmultipleHOPSarepresentwithintheaggregationsorarelocatedinnear–proximitytothewildmales.TheincreasedpresenceofHOPSwithintheaggregationsislikelyattributabletotwofactors.First,thenumberoftelemeteredHOPShasincreasedoverthelastfewyears,andsecond,anincreasingnumberofHOPSareachievingsexuallymaturitytostimulateparticipationinreproductiveeventssimilartothewildmales.Forexample,a2006yearclassHOPSwascapturedonMay23,andimplantedwithcode100.Largetesteswereobservedduringsurgicalprocedures,andhormoneanalysisclearlyindicatedreproductivestatus(T=141.51ng/ml).ThisHOPSmaleandseveralotherswerepresentwithinorontheperipheryofwildmaleaggregationsonseveraloccasions.TheextenttowhichthecontinuallyincreasingnumberofreproductivemaleHOPSwillinfluencereproductiveprocessesisuncertain.Forexample,asnumbersofsexuallymatureHOPSmalesincrease,willthenumberofmaleswithintheprimaryaggregation/spawningpatchdoubleortripleinfutureyearsorwillanincreasednumberofaggregationsformoveralargerspatialextentwhereeachaggregationincludesfewermales?

Spawningeventsinvolvingthreetelemeteredfemalepallidsturgeonwereverifiedin2017.Spawningfortwofemales(codes43,87)occurredwithinRM5.4–6.1ofthelowerYellowstoneRiverwheretheprimaryaggregationofmalesalsooccurred.Thisaggregationandspawningareaoverlappedwithverifiedspawningpatchesduringearlieryearsasidentifiedin2013(RM5.7–5.9),2014(RM5.3–5.8),and2015(RM5.8–5.9;DeLonayandothers,2016b,2016c;DeLonayandothers,inrevision).Differentfromfemalecodes43and87,spawningforcode41occurredatadownstreamlocation(RM3.7–4.1)andinvolvedareducednumberofmalesincomparisontothelargeraggregationupstream.Theresults,combinedwithpreviousstudies,expandinferencesidentifyingthelowerYellowstoneRiverasaconsistentspawningareaforpallidsturgeonandthatspawningmayoccuratoneormorepatches.AlthoughspawningmayoccurannuallyinthelowerYellowstoneRiver,isolatedaccountsofspawninghavealsobeenverifiedinotherareasincludingthePowderRiverduring2014andtheMissouriRiverdownstreamfromFortPeckDamin2011.WhereasmostspatialandtemporalattributesofspawninginthelowerYellowstoneRiverduring2017weresimilartopreviousyears,spawningoccurredatslightlycoolertemperaturesthanobservedinpastyears.Forexample,dailytemperaturesduringspawningeventsaveraged17.7–18.3oC(code43),18.3–18.8oC(code87),and19.2–19.3oC(code41).

PreviousverifiedspawningeventsinthelowerYellowstoneRiveroccurredatdailyaveragesof20.3–22.1oC.

SpawningpatchesusedbypallidsturgeoninthelowerYellowstoneRivercanbefunctionaltosupportfertilization,incubation,andhatchofembryosasevidencedfromcapturesofgeneticallyconfirmedpallidsturgeoninpastyears.Samplingin2017yieldedthegreatestnumberofAcipenseriformesfreeembryosandlarvaecollected(about1,700)todateinthelowerYellowstoneRiver,wheresamplingdownstreamfromknownspawningpatcheswasintensetoverifyspawnpatchfunctionalityinvolvingreproductiveeventsforknownreproductivefemalesandpotentiallynon–telemeteredreproductivefemales.ThespawnpatchatRM5.4–6.1usedbyfemalecodes43and87hasprovenfunctionalinpastyearstosupportincubation,hatch,anddrift–entryoffreeembryos.Confirmationofpallidsturgeonfreeembryosfollowingcompletionofgenetictestingwouldsimilarlyindicatereproductivefunctionalityofthispatchunderdifferentenvironmentalconditionsin2017.Confirmationofpallidsturgeonfreeembryosfromthecode41spawningpatch(RM3.7–4.1)wouldprovideinsightintoadditionalmainstemhabitatssupportingreproduction.ThepresenceofpallidsturgeonearlylifestagesfromthePowderRiverwouldyieldinitialverificationofsuccessfulincubation,hatch,anddrift–entryfromatributaryoftheupperMissouriRiverbasin.

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BRAATEN_TABLE 1. Dates and attributes of wild and hatchery-origin pallid sturgeon detected at Intake Dam, detected in the high-flow side channel, or translocated around Intake Dam. Apex data denote the date, river, and river mile where the fish was detected upstream from Intake Dam.

Origin Code Sex Intake Dam

High Flow Side Channel

(downstream) High Flow Side

Channel (upstream) Translocation Migration

Apex Apex River Apex RM

Wild 11 Male May 13, June 14 May 14 June 1 Powder 88.1 49 Male August 8 June 6 June 8 July 10-13 Yellowstone 99.1 57 Male May 17 61 Male June 14-July 10 June 8 June 8, 9, 10 June 13 Yellowstone 75.0 83 Male May 6-8, June 20 May 8 June 1 Powder 89.9 Hatchery 1 54 Female April 22, 25; June 15 May 6 May 10 Yellowstone 84.5 2 62 Male May 13, 14, 15, 20 66 Unknown May 24, July 13 June 11, 12 June 13 June 20 Yellowstone 76.1 3 68 Unknown May 4, 8, 9, 10, 15 72 Unknown April 7-11, several

dates April 13-July 27

90 Unknown May 12 91 Male April 3-5, several

dates April 10-24, May 1-10

May 10 June 9 Powder 97.0

4 98 Male August 18-20 117 Unknown July 4-6 124 Unknown July 25 5 140 Unknown Sept 11-13; Sept 15-

Oct 17

154 Unknown May 18-20, several dates

May 23-July 2

6 155 Unknown July 13, 14; several dates July 16-Sept 6

June 13, 16, 28

7 160 Unknown May 15, August 20 May 15 May 16 July 20 Yellowstone 123.4 169 Unknown May 2-6, August 13 May 9 June 13 Yellowstone 83.4 1 No eggs were detected by BOR personnel when captured for translocation on May 6 2017, 2Implanted with transmitter on May 3 2017 at RM 6.6 of the Yellowstone River, 3Implanted with transmitter on April 26 2017 at RM 70.9 of the Yellowstone River, 4 Implanted with transmitter May 16 2017 at RM 1,710.5 of the Missouri River, 5 Implanted with transmitter on September 5 2017 at RM 65.5 of the Yellowstone River, 6 Implanted with transmitter on May 3 2017 at RM 69.1 of the Yellowstone River, 7 Implanted with transmitter on April 17 2017 at RM 67.8 of the Yellowstone River

BRAATEN_TABLE 2. Samples and numbers of Acipenseriformes eggs, embryos, free embryos, and larvae sampled in the Yellowstone and Powder Rivers by date during June 2017.

Date Location Samples Acipenseriform eggs

and embryos Acipenseriform free embryos and larvae

6/7/2017 Yellowstone River 8 15 11 6/8/2017 Yellowstone River 4 14 7 6/9/2017 Yellowstone River 10 31 16

6/12/2017 Yellowstone River 10 21 32 6/13/2017 Yellowstone River 26 82 48 6/14/2017 Yellowstone River 32 71 45 6/15/2017 Yellowstone River 28 69 45 6/16/2017 Yellowstone River 30 67 63 6/18/2017 Yellowstone River 30 40 89 6/19/2017 Yellowstone River 30 63 124 6/20/2017 Yellowstone River 8 18 31 6/21/2017 Yellowstone River 18 15 56 6/22/2017 Yellowstone River 24 50 142 6/23/2017 Yellowstone River 28 38 147 6/24/2017 Yellowstone River 24 44 148 6/25/2017 Yellowstone River 42 39 242 6/26/2017 Yellowstone River 67 58 214 6/27/2017 Yellowstone River 58 59 225 6/12/2017 Powder River 6 0 17 6/15/2017 Powder River 22 0 14 6/19/2017 Powder River 18 5 4

EXPLANATION

4/1/17 5/1/17 6/1/17 7/1/17 8/1/17 9/1/17

iver d

iver t

Yellowstone dischargePowder dischargeYellowstone temperature

Braaten_Figure 1. Discharge and water temperature in the Yellowstone River during April – August 2017.

EXPLANATION

4/1/17 5/1/17 6/1/17 7/1/17 8/1/17 9/1/17 Tele

iver d

Pallid sturgeon percentYellowstone discharge

Braaten_Figure 2. Percentage of telemetered wild pallid sturgeon in the Yellowstone River and corresponding discharge, April – September 2017.

EXPLANATION

4/1/17 5/1/17 6/1/17 7/1/17 8/1/17 9/1/17

r mile

140 Pow

iver l

Code 11Code 49Code 57Code 61Code 83Code 91 (HOPS)

Intake Dam

Powder River confluence

Braaten_Figure 3. Movements and locations by date of five telemetered wild pallid sturgeon males (code 11, 49, 57, 61, 83) and one telemetered hatchery – origin pallid sturgeon (HOPS, code 91) migrating to Intake Diversion Dam (located at Yellowstone River RM 72.8) and into the Powder River (confluence located at RM 147.0 of the Yellowstone River) during 2017.

5/8/17 5/15/17

5/22/17 5/29/17

6/5/17 6/12/17

6/19/17 6/26/17

0123456789

DateYellowstone River location, in river miles

EXPLANATIONNumber of pallid sturgeon

Braaten_Figure 4. Aggregations of telemetered male pallid sturgeon by river mile location and date in the Yellowstone River, May–June 2017.

Braaten_Figure 5. Migrations and locations of reproductive wild female pallid sturgeon codes 43, 87, 41, and 127 by date in the Yellowstone River during 2017, and corresponding discharge and temperature conditions.

Title:Effectofwatervelocityongrowth,survival,andenergyreservesofendogenousPallidSturgeonScaphirhynchusalbuslarvae

Authors:JosephT.Mrnak,StevenR.Chipps,andDanielA.James

PallidSturgeon(Scaphirhynchusalbus)areafederallyendangeredspeciesendemictotheMissouriRiverbasinandthelowerMississippiRiver.Thelarvalphaseoffreshwaterfishesisoftencharacterizedbyhighmortality.Aswithmanyfishes,therecruitmentbottleneckforPallidSturgeonisbelievedtooccurduringtheirearlylifehistory.WatervelocityisbelievedtoplayanimportantroleinaffectingdispersalandsurvivalofendogenousPallidSturgeonlarvaeintheMissouriRiver.LarvalPallidSturgeonrequirealoticenvironmentaswellasaconnectedriversystemtocompletetheirendogenous-driftingphaseofdevelopment(Braatenetal.2008).Further,larvalPallidSturgeonrequirelongermigrationdistances,driftatfasterrates,andrequirealongerdurationtoswitchfromendogenoustoexogenousfeedingthanthesympatricShovelnoseSturgeon(Scaphirhynchusplatorynchus;Kynardetal.2002;Braatenetal2008).ThesedifferencesmayexplainwhyShovelnoseSturgeonaredoingwellwithintheMissouriRiverwhilePallidSturgeonarefacingreproductionandrecruitmentfailures.UnderstandingfactorsthataffectsurvivalofPallidSturgeonlarvaeiskeygiventheircriticalstatusandongoingrecoveryefforts.

Insummer2017,weevaluatedtheeffectsofwatervelocityongrowth,survival,andenergyreservesofendogenousPallidSturgeonlarvae(<18mmTL)usingamicrocosmexperiment.Oursystemwascomprisedoftwelve115Lovalstudytanks(Figure1)wherefishwereheldatasimilarwatertemperature(±SD)of16.3±0.3°C.Wetestedthreewatervelocitytreatments(fourreplicatespertreatment)characterizedasnovelocity(0cm/s−1),intermediatevelocity(range,1to7cm/s−1),orhighvelocity(2to16cm/s−1).

Totalenergycontentofthelarvae(J/gwetweight)wasmeasuredattwo-dayintervalsusingaParrmicro-bombcalorimeter.WerecordedtotallengthandmortalityofPallidlarvaefrom3to10dayspost-hatch.WeusedanalysisofcovariancetotestfordifferencesingrowthorenergyreservesovertimeandaTukeymultiplecomparisontestwasusedtoevaluatedifferencesinmortality.

GrowthrateofPallidSturgeonlarvaewassimilaracrosswatervelocities,rangingfrom0.76to0.84mm/d.However,energyreservesofPallidSturgeonlarvaemaintainedinthenovelocitytreatmentdeclinedsignificantlycomparedtolarvaeintheintermediateandhighvelocities.Moreover,larvaeinthenovelocitytreatmentexperiencedsignificantlygreatermortalitythatthosemaintainedintankswithflow(Figure2).Innaturalenvironments,areaswithnoflowmayposeasignificantsourceofmortalitytoendogenousPallidSturgeonlarvae.

In2018,additionalexperimentswillbeconductedtoevaluatethecombinedeffectsofwatertemperatureandvelocityongrowth,energyreserves,settlingtime,andmortalityofendogenousPallidSturgeonlarvae.

Figure1.Schematicofthetankdesignusedinthisstudy.Notetheexternalpump(blackbox;lower-right)whichisconnectedtoacontrollablevalve(notpictured;usedtomanipulatevelocity)leadingtoourflowapparatus(PVCwithoutflowholes).Thestandpipehasholesdrilledinittopromotecirculationthroughoutthesystemwiththescreenbufferactingtoincreasethesurfaceareaaroundtheoutflowholes(sothatthelarvaedonotbecomestucktothem).Notpicturedisthe400Lbaththatcontainedtwoovaltanks,twobioreactors,andtwoaerators.

Figure2.Plotshowingmeandaysposthatch(dph)to100%mortalityforendogenousPallidSturgeon(Scaphirhynchusalbus)larvaeamongthreetreatments;novelocity,intermediatevelocity,andhighvelocity.Thenumbersabovethebarssignifythemean(±SD)andthelettersrepresentstatisticaldifferences.

Products:

Presentations

Mrnak,J.M.,S.R.Chipps,andD.A.James.2018.Effectofwatervelocityongrowth,survival,andenergyreservesofendogenousPallidSturgeon(Scaphirhynchusalbus)larvae.2018MissouriRiverNaturalResourceConference.

Mrnak,J.M.,S.R.Chipps,andD.A.James.2018.Effectofwatervelocityongrowth,survival,andenergyreservesofendogenousPallidSturgeon(Scaphirhynchusalbus)larvae.2018UpperBasinPallidSturgeonWorkGroup.

Mrnak,J.M.,S.R.Chipps,andD.A.James.2018.Effectofwatervelocityongrowth,survival,andenergyreservesofendogenousPallidSturgeon(Scaphirhynchusalbus)larvae.54thAnnualMeetingoftheDakotaChapteroftheAmericanFisheriesSociety.

Awards

RobertA.KlumbMemorialScholarship,54thAnnualMeetingoftheDakotaChapteroftheAmericanFisheriesSociety(2018)

RobertA.KlumbMemorialTravelGrant,2018MissouriRiverNaturalResourceConference(2018)

7.25 (0.5); A

8.5 (0.57); B

9.75 (0.5); C

No Velocity Intermediate Velocity High Velocity

References:

Braaten, P.J., D.B. Fuller, L.D. Holte, R.D. Lott, W. Viste, T.F. Brandt, and R.G. Legare. 2008. Driftdynamicsof larvalpallidsturgeonandshovelnosesturgeon inanaturalsidechannelof theUpperMissouriRiver,Montana.NorthAmericanJournalofFisheriesManagement28:808-826.

Kynard, B., E.Henyey, andM.Horgan. 2002.Ontogenetic behavior,migration, and social behavior ofPallidSturgeon,Scaphirhynchusalbus,andShovelnosesturgeon,S.platorynchus,withnotesontheadaptivesignificanceofbodycolor.EnvironmentalBiologyofFishes63:389-403.

GenotypicAnalysesandParentalIdentificationsofJuvenileand

Sub-adultPallidSturgeonintheMissouriRiver

FY2017Report

February28,2018

MeredithBartronandJeffKalieMeredith_Bartron@fws.gov,Jeff_Kalie@fws.gov

U.S.FishandWildlifeServiceNortheastFisheryCenter

227WashingtonAve.,PO.Box75Lamar,PA16848(570)726-4995

Submittedto:StevenKrentz

Steven_Krentz@fws.govU.S.FishandWildlifeService

MissouriRiverFishandWildlifeConservationOffice3425MiriamAve

Bismarck,ND58501(701)250-4419

WayneNelson-Stastnywayne_nelsonstastny@fws.gov

PallidSturgeonRecoveryCoordinator55245NEHWY121CroftonNE68730

Billings,MT59101(402)-667-2884

Introduction

Pallidsturgeon(Scaphirhynchusalbus)areendangeredthroughouttheirrangeandwerelistedundertheEndangeredSpeciesActin1990.TheprimarylimitingfactorforpallidsturgeonrecoveryintheMissouriRiverappearstobealackofnaturalrecruitmentoverthepast25-30years.Becauseofthislack(orlowlevel)ofnaturalrecruitment,stockingofhatcheryproducedpallidsturgeonjuvenileshasbeenusedtosupplementandmaintainpallidsturgeon.AdultpallidsturgeonarecapturedannuallyintheMissouriRiverandtakentofishhatcheriesforspawning,afterwhichtheyarereturnedtothecapturearea.However,thepallidsturgeonrecoveryplanrequiresthatallhatchery-producedpallidsturgeonareidentifiablebysometypeoftag.Inthepast,offspringwererearedinhatcheriesuntiltheywerelargeenoughtobemarkedwithPITtagsorotherphysicaltags.

Typicallyjuvenilesremaininhatcheriesfornearlyayearbeforetheyreachthesizeatwhichtheycanbetagged,approximately140-220mm.Pallidsturgeonarehighlyfecundandwillproduceseveralthousandoffspringinasingleyear,resultinginlargenumbersofoffspringnecessarytomaintainseparatelyuntiltaggingsize.Hatcheryspaceconstraintsoftenlimitthenumberofjuvenilepallidsturgeonthatcanberetained,resultingincullingoflargenumbersofoffspringeachyear.Inhatcheries,juvenilepallidsturgeonarealsohighlysusceptibletooutbreaksofiridovirusthatcanseverelylimitsurvival.Inordertoreducethetimerequiredtorearpallidsturgeoninhatcheriesandallowgreaternumbersofjuvenilestobereleased,theuseofMendelianinheritedgeneticmarkersisaviablealternativetophysicaltags(DeHaanetal.2005;DeHaanetal.2008).Theuseofgenetictagscangreatlyincreasethenumberofpallidsturgeonthatcanbereleasedeachyearbyallowingtheirreleaseatsmallersizes.

ThegeographicfocusofthisprojectwastheupperandmiddleMissouriRiver.TheupperMissouriRiverisdefinedastheareaupstreamofGavinsPointDaminSouthDakotaandincludingtheYellowstoneRiveranditstributaries(RPMA1andRPMA2).ThemiddleMissouriRiver(RPMA3andRPMA4)extendsdownstreamfromGavinsPointDamtotheconfluencewiththeMississippiRiver.TherewerethreemainobjectivescompletedduringFY2015.Theseobjectivesinclude:

1) Estimatethedegreeofrelatednessamongadultpallidsturgeonatfederal(national)andstatefishhatcheries(NFHandSFH,respectively)tobeusedashatcherybroodstockfortheMissouriRiverandprovidematingplansforhatcheryspawning(MilesCityStateFishHatcheryandGarrisonDamNationalFishHatchery,withGavinsPointNationalFishHatcheryasneeded)

2) Addadultpallidsturgeontothegeneticbaselinedatasetusedtodistinguishhatcheryandnaturaloriginjuveniles

3) UsethebaselinedatasettoconductspeciesIDforanyunmarkedjuvenilesturgeoncollectedintheMissouriRiveranduseparentageanalysistodetermineifunmarkedjuvenilesidentifiedaspallidsturgeonarehatcheryornaturaloriginfish

Methods

Finclipspreservedin95%non-denaturedethanolwerecollectedbybiologistsparticipatinginmonitoringeffortsforjuvenileandadultputativepallidsturgeon.SampleswerereturnedtotheU.S.FishandWildlifeService(USFWS)NortheastFisheryCenterConservationGeneticsLabwithbiologicalinformationincludingPITtag,length,weight,samplinglocation,andsamplingdate.

DNAwasextractedusingthePurgenemethod(Qiagen,Valencia,CA).DNAconcentrationswereobtainedandconcentrationswerestandardizedforpolymerasechainreaction(PCR).DeHaanetal.(2005)identified17microsatellitelocithatcanbeusedforparentageanalysisinpallidsturgeonaswellasfordifferentiatingpallidandshovelnosesturgeon:Spl15,Spl18,Spl19,Spl26,Spl30,Spl34,Spl35,Spl36,Spl40,Spl56,Spl60,Spl101,Spl105,Spl106,Spl119,Spl158,Spl173(McQuownetal.2000).Twoadditionalloci(Spl12andSpl53(McQuownetal.2000))havebeenaddedtotheoriginalsuiteof17forstandardizationpurposeswithSouthernIllinoisUniversity,andtheywillbeusedforspeciesidentificationintheCentralLowlandsManagementUnit(CLMU)andInteriorHighlandsManagementUnit(IHMU)baselines.

Multiplexreactionswerecreatedtostreamlinetheamplificationprocess;fourpre-PCRmultiplexreactionswerecreated,with3to5lociwithineachreaction.LocusSpl26,Spl40,Spl53,andSpl105wereamplifiedseparately.LocusSpl26,Spl40,andSpl105wereaddedtooneofthemultiplexespost-PCR.LocusSpl53wasnotaddedtoamultiplexreactionandrunindividually.Forthemultiplexreactions,reagentconcentrationswerethesame.Each20uLPCRreactionconsistedof1.5�lofgenomicDNAextract,1.5XPCRbuffer(10mMTris-HCl,pH8.3;50mMKCl),3.75mMMgCl2,0.3175mMeachdNTP,0.12-0.80�Mofeachprimer(forwardprimerfluorescentlylabeled;AppliedBiosystems,FosterCity,CA),0.06unitsofTaqpolymerase(PromegaCorporation,Madison,WI),anddeionizedwateraddedtoachievethefinalvolume.SinglePCRreactions,Spl40andSpl105,were10ulPCRreactions,andeachconsistedof1.5�lofgenomicDNAextract,1.5XPCRbuffer(10mMTris-HCl,pH8.3;50mMKCl),3.75mMMgCl2,0.3175mMeachdNTP,0.12-0.24�Mofeachprimer(forwardprimerfluorescentlylabeled;AppliedBiosystems,FosterCity,CA),0.06unitsofTaqpolymerase(PromegaCorporation,Madison,WI),anddeionizedwateraddedtoachievethefinalvolume.Theamplificationcycleforallloci,exceptSpl105whichhadadifferentannealingtemperature,consistedofaninitialdenaturingat94°Cfor2min;35cyclesof94°Cdenaturingfor45sec,56°Cannealingfor45sec,72°Cextensionfor2min;anda30minextensionat72°C.LocusSpl105hadanannealingtemperatureof50°C.GenotypeswerevisualizedusinganABI3130(AppliedBiosystems,FosterCity,CA).GenescanandGenmappersoftwarefromAppliedBiosystems(FosterCity,CA)wasusedtoidentifyallelesateachofthe19loci.

Speciesidentification

Tranahetal.(2004)usedninemicrosatellitelocitodiscriminatepallidandshovelnosesturgeonintheupperMissouriRiverwithan82to95%probabilityofcorrectassignment.The17lociusedintheseanalysesincludedthelociidentifiedbyTranahetal.(2004)andadditionallocithatallowedthediscriminationbetweenpallidandshovelnosesturgeonwithahighdegreeofconfidence(DeHaanetal.2005).

GeneticbasedspeciesassignmentsanddetectionofhybridizationwereaccomplishedusingthecomputerprogramNewHybrids(AndersonandThompson2002).ThisBayesian-basedmethodusesmarkersthatdifferinallelefrequencybutdonothavefixeddifferencesbetweenknownbaselinegroups,(suchaswithpallidandshovelnosesturgeonintheupperandmiddleMissouriRiver),andthemodelcomputestheposteriorprobabilitythateachindividualbelongstooneofthetwospeciesoroneoffourclassesofhybrids(F1’s,F2’s,andbackcrosses).Individualswereclassifiedasapallidsturgeoniftheprobabilityofassignmenttoknownpallidsturgeonwas95%orgreater,basedonmethodsdevelopedbyUSFWSAbernathyFishTechnologyCenterandinconjunctionwithDr.EdHeist(SouthernIllinoisUniversity).However,forindividualssampledinthelowerportionofthebasin(RPMA3&4),iftheprobabilityofassignmentis90%orgreater,origindeterminationisalsoconductedduetotheslightlyreducedabilitytodistinguishpallidandshovelnosesturgeonbasedonallele-frequencydifferencesbetweenbothspecies.

Hatcheryversusunknownoriginidentification

Followingspeciesidentification,geneticparentageanalysiswasusedtodetermineifapallidsturgeonoriginatedfromthehatcheryprogramorwasnaturallyproducedwithintheMissouriRiver.Multi-locusgenotypesforalmosteveryhatchery-spawnedadultsince2000havebeenobtainedat17microsatelliteloci(seeobjectives1&2),andgenotypedataarestoredinaMicrosoftAccessdatabasedevelopedandmaintainedbyNEFC.AtaggingdatabasedevelopedbyUSFWSMissouriRiverFWMAOmaintainsadditionalinformationsuchasspawningandstockinginformation,andthisdatabaseisusedtoreferencegeneticparentageassignmentstoknownspawningpairsandstockinglocations.

ParentageassignmentswereconductedusingCervus(ver3.0;Kalinowskietal.2007).Geneticparentageassignmentsoccurusingmodifiedexclusionbasedmethodallowingforasinglemismatchintheoffspring-parent-parenttriplet.Ifajuvenilefishisnotcompatibleattwoormorelociwithaparticularhatchery-spawnedpair,thenthatpairisexcludedaspotentialparentsofthatjuvenilesturgeon.DeHaanetal.(2005)determinedthatbyusing17highlyvariablelociandallowingforasinglemismatchtoaccommodateforgenotypeorlaberrors,theprobabilityofanincorrectmatchwasverylow.ParentageassignmentswerecomparedtothespawningdatabasemaintainedbyUSFWSMissouriRiverFishandWildlifeConservationOfficetoconfirmifageneticallyassignedspawningpairrepresentedaknownspawningpair.Ifthejuvenilefishwasnotassignedtoanyhatcheryparents,thentheindividualwasidentifiedasunknownorigin.Additionally,asmallnumberofbroodstockhavenotbeengenotypedandthereforearenotavailableforparentageassignment,andsomespawningrecordsareincompleteforindividualspawningpairs(oneorbothparentslistedas“unknown”or“mixture”).Thus,ifnotassignedtoadocumentedspawningpair,resultscannotbeconfirmedifafishisnotofhatcheryoriginorwildsimplybecausetheyarenotassignedtohatcheryparents.Therefore,individualsnotassignedtohatcheryfamiliesareidentifiedas“unknown”origin.

Results

Objective1–EstimatethedegreeofrelatednessamongMissouriRiverbroodstock

Duetothelimitednumberofpallidsturgeonbroodstockavailableduringaspawningseason,geneticinformationwasusedtohelpreducethepotentialforinbreedingandtomaintaingeneticdiversityduringhatcheryproduction.Relatednessestimatesofadultpallidsturgeonbroodstockareusedtoidentifyspawningpairstoavoid;suchascrossesbetweenfullandhalfsiblings,andtoallowfortheminimumdegreeofrelatednessamongfamiliescreated.Pairwiserelatednessvalues(Rxy)weredeterminedbetweenallindividualsusingmulti-locusgenotypesforallpairsofbroodstockusingthecomputerprogramSPAGeDi(HardyandVekemans2002),basedonrelatednessalgorithmofQuellerandGoodnight(1989).

Potentialbroodstockaregenotypedat17microsatelliteloci.Forpotentialbroodstock,thespecies(pallid,shovelnose,orhybrid)wasdetermined,andforindividualsidentifiedaspallidsturgeon,origin(hatcheryorunknown)wasassessed.AmatingplanwasdevelopedforbroodstockofreproductivematurityatGarrisonDamNationalFishHatchery(GDNFH).Cryopreservedmiltfrommalespreviouslycapturedforspawningwasalsoconsideredinthespawning.

OnebroodstockreportwasprovidedduringFY2017.ThereportmadespawningrecommendationsforfourreproductivepallidsturgeonfemalesandninereproductivepallidsturgeonmalesatGDNFH(KalieandBartron2017).Also,apotentialof90pallidsturgeonmalesthathadbeenpreviouslycryopreservedatGarrisonDamNFHwerealsoincludedinthereport.Allpotentialbroodstock,includingthecryopreservedmilt,weredeterminedgeneticallytobepallidsturgeon(Table1).

Additionally,priorityscoreswerealsoassessedtoaidinfieldcollectioneffortsofbroodstockthathadnotpreviouslybeenspawnedortoavoidspawningindividualsthathadalreadycontributedoffspringtomultiplespawningevents.Thesepriorityscoresweredistributedpriortobroodstockcollectionefforts,andincorporatedupdatedretentiontargetsofcaptiveindividualsmaintainedatGavinsPointNationalFishHatcheryandupdatedspawningandcapturerecordsfromRyanWilson(USFWS).PriorityscoresareupdatedyearlybasedonrecaptureratesandretentiontargetsofcaptivebroodstockdeterminedbyGPNFH.Retentiontargetsofcaptivebroodstockwillbedeterminedonanindividualbasisratherthanafamilybasisfor2019.

Table1.Summaryresultsofthe2017broodstockanalysisbyhatchery.Speciesresultsincluded:PD(Pallid),SH(Shovelnose),HY(Hybrid),andoriginresultsincludedHatchery(HA)orunknown(UN).

Results-speciesIDResults-Origin Hatchery PD SH HY HA UN GDNFH 103***103***Includes90cryopreservedmales

Objective2–Continuetoaddadultpallidsturgeontothegeneticbaselinedataset

Broodstockcollectioneffortsgenerallycapturemoreadultsthanareeventuallyspawnedbecausenotalladultsarereproductivelyviableinagivenspawnyear,reproductiveviabilitycannotnecessarilybedeterminedattimeofcollection,oradultswerecollectedforbroodstockuseinfutureyears.TheseadditionaladultscollectedfromtheMissouriRiverarealsogenotypedandcharacterizedforspeciesandorigindetermination.Becausetheseadditionaladultsarereturnedtotheriver,theydohavethepotentialtoreproduceinthewildinsubsequentyears.Inclusionoftheseadultsintothebaselinedatasetisusefulforfutureanalysisofnaturalreproduction.

Atotalof90additionaladultsorbroodstockweregenotypedandincludedintothegeneticbaselinefollowingspeciesandorigindetermination(Table2:Adults(AD)andBroodstock(BR)).FiveindividualsweresampledfromRPMA1,30individualsfromRPMA2,noindividualsfromRPMA3,and55individualsweresampledfromRPMA4.Speciesidentificationwasfirstperformedtodetermineifsamplesreceivedwerefrompallidsturgeon,shovelnosesturgeon,orahybridbetweenpallidandshovelnose.Ofthe90samplesanalyzed,88wereidentifiedtobepallidsturgeon,zeroindividualswereidentifiedasshovelnose,and2wereidentifiedtobehybrids.Ofthe88pallidsturgeonidentified,40wereofhatcheryoriginand48wereofunknownorigin(Table2).

Table2.SummaryofthesamplesreceivedduringFY2017forgeneticanalysis,byRPMA,lifestage,species,andoriginfortheadult(AD)andbroodstock(BR)samples.BroodstocksamplesfromTable1arenotincludedintheadultcount.Speciesresultsincludepallid(PA),shovelnose(SH),hybrid(HY),andunknown(UN).Originwascalculatedforindividualsidentifiedaspallidsturgeon,andwaseitherhatchery(HA)orunknown(UN). Lifestage Species Origin RPMA AD BR PA SH HY HA UN 1 4 1 5 0 0 4 12 20 10 30 0 017133 0 0 0 0 0 0 04 5 50 53 0 21934 Total 29 61 88 0 24048

Objective 3 – Conduct genetic parentage analysis for unknown juvenile pallid sturgeon to

determine hatchery vs. natural origin

Atotalof314putativepallidsturgeonsampleswereprovidedfromlarvae,young-of-year,or

juvenilesforspeciesandorigindetermination(Table3).ThisdoesnotincludeProject3.7 samplesor

captiveoffspring.TwoindividualsofthissizeclassweresampledfromRPMA1,77individualswere

sampledfromRPMA2,23individualsweresampledfromRPMA3,and212sampleswerefromRPMA4.

Geneticspeciesidentificationwasfirstperformedtodetermineifsamplesreceivedwerefrompallid

sturgeon,shovelnosesturgeon,orahybridbetweenpallidandshovelnose.Parentageanalysiswasalso

determinedforallpallidsturgeon.Ofthe314samplesprovided,atotalof247pallidsturgeonwere

identified,41weredeterminedtobeashovelnosesturgeon,17weredeterminedtobehybrids,2

individualsweretriploid,and7individualsdidnotamplify.Allhybrid,triploid,andnon-amplifying

individualswerefromRPMA4.Ofthe247samplesidentifiedtobepallidsturgeon,235wereof

hatcheryoriginand12wereofunknownorigin(Table3).Resultsfromallsamplesreceivedwere

providedtothebiologist(s)whocollectedandsentthesample.

Table3.SummaryofthesamplesreceivedduringFY2017forgeneticanalysis,byRPMA,lifestage,species,andoriginforthelarvae(Lar),young-of-year(YOY),andjuvenile(JU)samples.Speciesresultsincludepallid(PA),shovelnose(SH),hybrid(HY),andunknown(UN).Originwascalculatedforindividualsidentifiedaspallidsturgeon,andwaseitherhatchery(HA)orunknown(UN). LifestageSpeciesOrigin RPMA Lar YOY JU PA SH HYTriploid/NoAmp. HA UN 1 0 0 2 2 0 0 0202 03047 4631 004603 0 023 23 0 002304 01220017610179164 12 Total 0422722474117923512IncontinuingwithinheritancetestingofcaptiveoffspringatGavinsPointNationalFishHatchery,73pallidsturgeonwerealsoanalyzedin2017(Table4).72hatcherycrosseswereconfirmed.1individualwastriploidandcouldnotbeanalyzed.Thetriploidsamplewasfrom2016.

Table4.SummaryofcaptiveoffspringsamplesreceivedduringFY2017forgeneticanalysisbyGPNFHbyyearclass,numberofindividualsperyearclass,confirmedhatcherycrosses,andtriploidindividuals. YearClass #IndividualsYearClass#Confirmedhatcherycrosses#Triploidindividuals201533330201640391

GeneticanalysisofunmarkedpallidsturgeoninRPMA1and2(Project3.7)wasalsocompletedwithsupplementalfundingbyMontanaFishWildlifeandParks.301individualswereanalyzedforspeciesidentificationandhatcheryvsunknownoriginidentification(Table5).194sampleswerecollectedinRPMA1,and107sampleswerecollectedinRPMA2.Allsamplesweredeterminedtobepallidsturgeonandhatcheryorigin.Therewere75differentfamiliesand16differentyearclassesrepresentedfromthe301hatcheryoriginindividualscollectedinRPMA1and2in2017(Table6).

Table5.SummaryoftheProject3.7samplesreceivedduringFY2017forgeneticanalysis,byRPMA,lifestage,species,andoriginforjuvenile(JU)samples.Speciesresultsincludepallid(PA),shovelnose(SH),hybrid(HY),andunknown(UN).Originwascalculatedforindividualsidentifiedaspallidsturgeon,andwaseitherhatchery(HA)orunknown(UN). LifestageSpecies____Origin RPMAJUAD PA SH HYTriploidHAUN 11931 194000194021070107 0 001070____Total 30013010003010

Table6.2017Project3.7samplesbrokedownbyRPMAandyearclass.

RPMA FamilyFemale FamilyMale YearClass#IndividualsYear

Class1 1F4A301354 7F7D291A07 1997 11 132213574A 1F482F3F2B 2005 21 4443240458 444334021A 2005 21 1F497F1801 1F4A0B1A72 2006 21 1F497F1801 1F4A3E1445 2006 11 1F497F1801 444171072D 2006 41 1F497F1801 466C473C59 2006 21 115557165A 1F47760123 2007 21 115557165A 431565767B 2007 11 115557165A 7F7D291A07 2007 11 1F4A436E66 115631222A 2007 21 454B380D60 2204583665 2007 11 470378405D 1F4B26036D 2007 11 47151A3D3A 115669294A 2007 11 47151A3D3A 7F7D372A6B 2007 11 7F7FD66963 115525534A 20072009 41 115557463A 220E5E551E 2008 21 115557463A 4310556551 2008 11 115557463A 444334021A 2008 31 1F497F1801 115712453A 2008 11 1F497F1801 1F4849755B 2008 21 1F497F1801 7F7D2D723D 2008 21 1F497F1801 7F7F066471 2008 11 470A675627 7F7E55466D 2008 11 470A675627 7F7F066471 2008 21 7F7F066452 7F7D437250 2008 41 115557165A 115679523A 2009 1

1 115557165A 470A754E14 2009 51 115557165A 7F7D365422 2009 111 115557165A 7F7F06697C 2009 101 1F4848153C 1F4A555072 2009 11 1F4848153C 424E680B49 2009 11 220F01755C 43105C602B 2009 31 220F01755C 4704550E5B 2009 61 220F01755C 7F7D37642C 2009 41 4315327C7B 4718447879 2009 21 454B490528 1F477B3A65 2009 21 454B490528 435F71414F 2009 21 454B490528 44440A7B73 2009 11 470468383C 1F4A13453F 2009 21 470468383C 47037F3026 2009 31 470468383C 7F7B023408 2009 31 7F7FD66963 220E4E4E5D 2009 31 7F7FD66963 465B6F1939 2009 61 1F5569653E 132313521A 2010 11 1F5569653E 1F4A33194B 2010 41 1F5569653E 7F7D24754C 2010 31 43105F0C7E 1F4A143350 2010 51 43105F0C7E 44436E2975 2010 21 43105F0C7E 4704550E5B 2010 61 6C00024873 116165646A 2010 31 486A080614 7F7B024F2D 2012 11 462C7B2F49 1F4A435004 2013 21 462C7B2F49 1F4B225A1A 2013 91 462C7B2F49 487F4B1745 2013 11 7F7D517479 486838404F 2014 101 7F7D517479 7F7D433241 2014 41 1F48421542 115556461A 2015 91 1F48421542 1F53312736 2015 51 1F48421542 7F7D376F73 2015 121 470378405D 220F0E6207 2016 11 470378405D 220F107A6F 2016 21 7F7D517479 7F7D7C2447 2016 12 220E345E09 1F4A111C6A 2001 22 220E345E09 1F4A27214F 2001 22 116224546A 1F477B3A65 2002 12 116224546A 220F107A6F 2002 102 116224546A 452A4E1F15 2002 12 7F7F054855 115669540A 2003 12 115557165A 1F50072169 2005 1

2 4443240458 444334021A 2005 22 1F497F1801 1F4A0B1A72 2006 82 1F497F1801 1F4A3E1445 2006 52 1F497F1801 444171072D 2006 32 1F497F1801 466C473C59 2006 32 115553544A 115556461A 2007 12 115553544A 4441774C6E 2007 12 115557165A 7F7D291A07 2007 12 47151A3D3A 115669294A 2007 12 7F7FD66963 115525534A 2007,2009 22 115557463A 220E5E551E 2008 12 115557463A 4310556551 2008 12 1F497F1801 115712453A 2008 42 1F497F1801 1F4849755B 2008 22 1F497F1801 7F7D2D723D 2008 12 1F497F1801 7F7F066471 2008 12 470A675627 115626162A 2008 32 470A675627 7F7F066471 2008 22 115557165A 115679523A 2009 22 115557165A 7F7D365422 2009 12 115557165A 7F7F06697C 2009 22 220F01755C 43105C602B 2009 42 220F01755C 4704550E5B 2009 62 220F01755C 7F7D37642C 2009 112 4315327C7B 7F7B082C10 2009 12 454B490528 1F477B3A65 2009 12 470468383C 47037F3026 2009 22 7F7FD66963 465B6F1939 2009 12 1F5569653E 132313521A 2010 12 1F5569653E 1F4A33194B 2010 12 1F5569653E 7F7D24754C 2010 42 43105F0C7E 4704550E5B 2010 12 6C00024873 116165646A 2010 12 7F7D517479 486838404F 2014 12 1F48421542 115556461A 2015 12 1F48421542 1F53312736 2015 32 1F48421542 7F7D376F73 2015 22 4A46717168 7F7D23292E 2017 1

In2017,standardizationandupdatingofbaselinesfortheCentralLowlandsManagementUnitandInteriorHighlandsManagementUnitcontinuedincollaborationwithDr.EdHeistfromSouthernIllinoisUniversity.Wecomparegenotypes(QAQC)onallindividualsaddedtothesebaselines.

Additionalanalyses

WealsoanalyzedjuvenilescollectedaspartoftheevaluationofalarvaldriftstudyconductedbytheUpperBasinWorkgroupmembersin2016.Thestudyreleased~700,0001-dph(daysposthatch)PallidSturgeonfreeembryosintheMissouriRiverneartheMilkRiverconfluencetoevaluatedriftdynamics.In2017,aspartofthejuvenilesamplingeffort,onejuvenilesample(Sturg-10965/PITtag6C00097722)wasdeterminedtobefromthe2016MissouriRiverPallidSturgeonFreeEmbryoDriftStudy.Itwascollectedon8/25/2017byMRFWMAO.Geneticresultsconfirmedthisindividualoriginatedfromfamilycross1F497F1801x0A180E0E7Espawnedon6/21/2016.Thisfamilycrosswasspawnedspecificallyforthelarvaldriftstudyanditsoffspringwerestockedoutonlyforthestudypurposeon6/27/2016.

Alsoin2017,TheUSFWSNortheastFisheryCenter(NEFC)ConservationGeneticsLabinLamar,PAreceivedtwentytwovialsofpallidsturgeoneggs(~20pervial)fromWarmSpringsFishTechCenter(WSFTC)onAugust30,2017.Eggsfromdifferentfamilygroupsresultingfrommalesthatwerecryopreservedusingdifferentmethodswerepreservedforassessmentofreproductivestatus.However,therewasconcernthatthetubelabelsmaynothavereflectedthecross(andpreservationmethod),andsothemaleparentcontributingtoeachfamilyandgroupofeggswasunknown.Withoutdeterminationofthemaleparent,thenthesuccessofthevariouscryopreservationmethodscouldnotbeassessed.

Followingreceiptofthevials,DNAwasisolatedfromtheeggsusingaPurgeneDNAextractionprotocol(Qiagen,Valencia,CA).DNAwasthendilutedwithanequalvolumeofreagentgradesterilewater.PolymeraseChainReaction(PCR)wasthenperformedon96samples(4-6eggsfromeachvial)at19lociandgenotypesforthefullsuiteoflociwereacquired.Thegeneticresultsindicatedthatthetubesweremislabeledforvials1through10.Geneticresultsalsoindicatedvial6containedeggsfertilizedbytwocryopreservedmalesusedinthestudy.Vials11through22matchedthelabelingonthevialsforfamilycross.ResultswereprovidedtoWSFTCsotheycouldcompletetheevaluationofcryopreservationmethod.

References

Anderson,E.C.andE.A.Thompson.2002.AModel-BasedMethodforIdentifyingSpeciesHybridsUsingMultilocusGeneticData.Genetics160:1217–1229.Banks,M.A.andEichert,W.2000.WHICHRUN(version3.2):Acomputerprogramforpopulationassignmentofindividualsbasedonmultilocusgenotypedata.JournalofHeredity91:87-89.DeHaanP.W.,D.E.Campton,andW.R.Ardren.2005.Genotypicanalysisandparentalidentificationofhatchery-originpallidsturgeonintheUpperMissouriRiver:PhaseIInheritanceofMicrosatellite,NuclearDNAMarkers.June23rd,2005.35pp.USFWSAbernathyFishTechnologyCenterFinalReport.DeHaanP.W.,G.R.Jordan,andW.R.Ardren.2008.Useofgenetictagstoidentifycaptive-bredpallidsturgeon(Scaphirhynchusalbus)inthewild:improvingabundanceestimatesforanendangeredspecies.ConservationGenetics9:691-697.GoodknightK.F.andQuellerD.C.1999.Computersoftwareforperforminglikelihoodtestsofpedigreerelationshipusinggeneticmarkers.MolecularEcology8:1231-1234.Kalie,J.andM.L.Bartron.2017.2017MatingPlanforUpperMissouriRiverPallidSturgeonBroodstock:GarrisonDamNationalFishHatchery.June27,2017,providedtoGarrisonDamNationalFishHatcheryMcQuown,E.C.,Sloss,B.L.,Sheehan,R.J.,Rodzen,J.Tranah,G.J.andMay,B.2000.Microsatelliteanalysisofgeneticvariationinsturgeon:newprimersequencesforscaphirhynchusandacipenser.TransactionsoftheAmericanFisheriesSociety129:130-1388.QuellerD.C.andGoodnightK.F.1989.Estimatingrelatednessusinggeneticmarkers.Evolution43:258–275.Snyder,D.E.2002.Pallidandshovelnosesturgeonlarvae–morphologicaldescriptionandidentification.JournalofAppliedIchthyology18:240-265.Tranah,G.,D.E.Campton,andB.May.2004.Geneticevidenceofhybridizationofpallidandshovelnosesturgeon.JournalofHeredity95:474-480.

Pallidsturgeonlarvaldrift,developmentandswimmingabilities

EXAMINATIONOFPALLIDSTURGEON(Scaphirhynchusalbus)LARVALDRIFT,DEVELOPMENT,

ANDSWIMMINGABILITIES

FinalreportSubmittedby

DavidRussellDockeryWildRiversConsultingLivingston,MT59047

dockery.david@gmail.com

KevinM.KappenmanU.S.FishandWildlifeService

BozemanFishTechnologyCenterBozeman,MT59715

kevin_kappenman@fws.gov

March2018

ACKNOWLEDGEMENTSIwouldliketothanktheBozemanFishTechnologyCenter,UpperBasinPallidSturgeon

WorkgroupandWesternAreaPowerfortheirsupport,selectionandfundingofthestudy.Iwouldliketothankallthescientiststhathavedevotedtheirtimeandlivestopallidsturgeonrecovery.Thequalityandquantityofpreviousresearch,thesynthesisofknowledge,andthecollaborationamongcolleaguesisinspiring.Thisprojectwasmadepossiblebythecollaborationandsupportofmultipleagenciesandindividuals.WewouldliketothankGavinsPointNationalFishHatchery,JeffreyPowell,ChrisHooley,andstaffforspawningfishandprovidingeggsandtheMissouriRiverNaturalResourcesCommitteeforhelpwithfundingandcontracting.Theprojectwouldnothavebeenpossiblewithoutthehardwork,support,andpatienceofBenHendrickson,ChristerWheat,andKevinKappenman.JasonIlgenisthankedforhishelpandexpertise.

EXECUTIVESUMMARY

Sustainablepallidsturgeonnaturalrecruitmenthasnotbeenobservedsincetheidentificationofthespecies.Mortalityassociatedwithanextendedlarvaldriftphaseofdevelopmentisattributedtoanalmostcompletelackofobservedrecruitmentinthelast50years.Larvaearehypothesizedtodriftintoreservoirhabitatandsettleinananoxicbottomlayer,resultinginmortality.Debateexistsonlarvaldriftbehavior,durationanddistance.Toassesscurrenthypotheses,wemeasuredtherelationsamonglarvaldevelopment,settlingbehavior,velocity,temperature,andhabitat.Weobservedastrongrelationshipbetweentemperatureanddevelopment,withmostembryosobservedtransitioningtoactivelyfeedinglarvaeby23daysposthatch(dph)at15°Ccomparedto13dphat20°C.Mostembryosdevelopedbottomsettlingbehaviorat9dphat20°Cand~13dphat15°C.However,embryos/larvaecycledbetweendriftandbottomorientationuntil30dphin0.61mdiametercirculartanksand71dphinalargeovalartificialriver(20mcircumference).Swimmingstudiesindicatedthatlarvaeareweakswimmersandbottomvelocitiesofselectedsettlementareas(<15cm/s)approximatedmaximumsustainedswimmingvelocities.Flatsmoothsubstrateswereselectedandfoodavailabilityappearedtoaffectdistribution.Competitionappearedtocontributetoextendeddrift.Basedonobservations,wehypothesizethedriftphaseofdevelopmentwillbeextendedifsuitablerearinghabitatisnotavailable.Dammanagementpracticesthataimtorestorenaturaltemperatureregimesandincreasetemperatureofreleasedwaterwillgreatlydecreasedriftdurationanddistances.Weobservednoevidencethatflowmanipulationwillaffectlarvaldevelopmentrates,butitwillcertainlyaffectdriftspeed,driftdistances,andhabitatavailability.

EXAMINATIONOFPALLIDSTURGEON(Scaphirhynchusalbus)LARVALDEVELOPMENT,

BEHAVIORANDSWIMMINGABILITIES

INTRODUCTION

Sturgeon(Acipenseridae)originated200-250millionyearsagoandremainonetheoldestextantfamilyofspecies(Carmonaetal.,2009).Despitesurvivingmultiplemassextinctioneventsandglaciation/deglaciationeventsthatdramaticallychangedthelentic,lotic,andmarinelandscapes,26ofthe27extantspeciesofsturgeonarenowlistedasvulnerable,endangered,orcriticallyendangered(BillardandLecointre,2001;LorkeandYew,2005;Carmonaetal.,2009).Pallidsturgeon(Scaphirhynchusalbus)areamongtherarestsurvivingfishspeciesinNorthAmerica(Kallemeyn,1983).

PallidsturgeonareendemictotheMissouriandMississippiRiversandsomeoftheirlargertributariesandwerefirstidentifiedin1905asaseparatespeciesthanshovelnosesturgeon(Scaphirhynchusplatorhynchus),asympatriccongener(ForbesandRichardson,1905).Littlewasknownaboutpallidsturgeonuntilthelate20thcenturyandearlyreportsfromcommercialharvestindicatethattheywererelativelyrarecomparedtoshovelnose,oftenlessthan10%ofthecatchofriversturgeon,andweremostfrequentlyobservedintheupperreachesoftheMissouriintheDakotasandMontana(ForbesandRichardson;1905,BaileyandCross,1954;DryerandSandvol,1993).Commercialharvestandpollutionareassociatedwithinitialdeclinesofriversturgeon,witha10folddeclineinharvestmassobservedbetweenthe1890’sand1950(Carlander,1954;WhitleyandCampbell,1974).However,harvestintheUpperMissouriwaslikelynegligibleornonexistentandnowfewerthan175naturallyproducedpallidsturgeonareestimatedtoliveintheUpperMissouriBasinaboveLakeSakakaweainNorthDakota(Kallemeyn,1983;DryerandSandvol,1993;USFWS,2014).SurvivingwildsturgeonintheUpperMissouriRiverBasinareestimatedtobeatleast44yearsold(Braatenetal.,2009).

DammingoftheMissouriRiverbeganin1926andsixlargemainstemdamswerebuiltby1952(DryerandSandvol,1993).Extirpationanddeclineoflocalshovelnosesturgeonpopulationswasnotedbythemid-20thcenturyandassociatedwithdamming(BaileyandCross,1954).Damscanbedamagingtolargeriverspeciesbecausetheyfragment,inundateandeliminatecriticalhabitat,isolatepopulations,alterflowandtemperatureregimesandreducesedimenttransport,turbidity,naturalchanneldevelopmentandfloodplainconnectivity/productivity(BaileyandCross,1954;DryerandSandvol,1993;Nilssonetal.,2005).Allhistoricalpallidsturgeonhabitathasalteredflowregimes,36%ofhistoricalpallidsturgeonhabitathasbeeneliminated,and40%hasbeenchannelized(DryerandSandvol,

1993).Becauseofanextendedlarvaldriftphaseofembryonicdevelopment,pallidsturgeonareparticularlysusceptibletohabitatfragmentation(Kynardetal.,2002,2007).

DespiteevidenceofsuccessfulspawningofpallidsturgeonintheUpperMissouriBasin(USGS,2007;Fulleretal.,2008;DeLonayetal.,2016),evidenceofnaturalrecruitmenthasbeenextremelyrareforalmost50years,suggestingarecruitmentbottleneckduringembryonicdevelopment(USFWS,2000;FullerandHaddix,2012;Braatenetal.,2008,2012a;Guyetal.,2015).Pallidsturgeonembryosexhibitaswimupanddriftdispersalbehaviorafterhatchinguntil~9-11daysposthatch(dph;temperaturedependent),whenlarvaebeginexogenouslyfeedingandareassumedtosettleonthebottom(Conteetal.,1988;Kynardetal.,2002,2007).

Estimatesofdriftdistancesfromlaboratoryandfieldexperimentssuggesttheremainingsegmentsoffree-flowingMissouriRiverarenotlongenoughforembryostodevelopandtheylikelyendupinreservoirsortransitionzonesbetweenriversandreservoirs(Kynardetal.,2002,2007;Braatenetal.,2008,2010,2012a).Fieldstudiesidentifiedanoxicconditionsnearthebottomintransitionzonesbetweenriversandreservoirsthatresultedinembryonicdeathwithinanhourwhenreplicatedinalaboratory;apparentlyidentifyingthecauseofrecruitmentbottleneck(Guyetal.,2015).However,skepticsofthishypothesisnotethatthevastmajorityofembryos/larvaeinriverdriftstudiesarenotrecoveredandtheirbehaviorinrelativelysimplelaboratoryenvironmentsmaynottranslatetothecomplexhydraulicenvironmentsoflargerivers(Braatenetal.2008,2010,2012a;MarotzandLorang,2017).Additionally,detailedflowmappinganddriftmodellingindicatetheUpperMissouriisverydispersivetoparticlesandhasmanyretentionareasthatshouldprovideembryosenoughtimetodevelop(MarotzandLorang,2017).

Thepurposeofthisstudywastoexaminetheeffectsofabioticfactorsonlarvaldevelopmentandbehaviorinordertobetterinformdammanagementandreassessthecurrentlarvaldrifthypothesis.Theeffectsoftemperatureandvelocityonlarvaldevelopmentwereexaminedinsmallcircularchannels.Habitatselectionandlarvalbehaviorwereexaminedinalargeartificialriverwithacomplexhydraulicenvironmentandadiversityofsubstratesandhabitats.Larvaewereobservedafterexogenousfeedingbegantoidentify‘post-settling’behavior.Additionally,swimmingabilitiesoflarvaewereexaminedtoallowinferencetosuitablebottomvelocitiesforsettlinglarvae.Whileextensivestockinghassustainedthespecies,theultimategoalofanaturallyreproducingandpropagatingspeciesisoutofreachuntilthefactorscontributingtothelackofrecruitmentarebetterunderstood(USFWS,2000;USFWS,2008).

METHODS

TESTFISHANDFACILITIES

Freeembryosusedinexperimentswerefromtwodistinctspawningeventsandparentage.EggswerecollectedfrompallidsturgeonheldatGavinsPointNationalFishHatchery(GPNFH;Yankton,SouthDakota,U.S.)andspawnedon25May2017and13June2017.Inbothspawningeventseggswerehandstrippedfromthreefemalesandpairedwithspermfromthreemalestoprovidethreecrosses.Eggswerefertilizedat16.9°Candstirredwithamixtureofbentoniteclayandwaterfor20mintoeliminateadhesiveness(VanEenennaametal.,2001).FertilizedeggsweretransportedinaninsulatedcoolerfromGPNFHtotheBozemanFishTechnologyCenter(BFTC;Bozeman,Montana,U.S.).TemperatureduringtransportwasmonitoredwithanErtcoHighPrecisionThermometer(BarnsteadInternational,Dubuque,Iowa)andvariedlessthan1.0°Cfromthetemperatureatthetimeoffertilization(16.9°C).UponarrivalattheBFTC,eggsfromallcrosseswerethoroughlymixedandtreatedwiththedisinfectantOvadine(BufferedPVPIodine;10mL/L)for10min.Eggswereacclimatedtoincubatingtemperaturesbyplacingbagsinawaterbathandgraduallyaddingwatertoreachthedesiredtemperature(±0.5°Cevery20min).Alleggsfromthefirstspawningeventwereincubatedat16.1±1.0°Cwhereaseggsfromthesecondspawningeventweresplitandincubatedattwowatertemperatures:15.5±0.5°Cand20.5±0.5°C.

Eggswereincubatedin0.5LMcDonaldjarsprovidedwithflowthroughwater(0.15–0.2L/min).Waterfromon-sitewarmandcoldspringswasmixedtoobtainthedesiredtemperatureandcontinuouslypassedthroughapacked-columndegassingsystem.Thedegassingsystemremovedsupersaturatednitrogen,reducedtotaldissolvedgaslevels,andmaintainedgaslevelsatacceptablerearingcriteriaforaquaticspecies(Kappenmanetal.,2013).Averagedissolvedoxygenwas7.24and7.07mg/Lat15and20°C,respectively.Watertemperatureandcumulativethermalunits(CTU)wererecordedhourlythroughoutallexperimentswithOpticStowawayTempDataLoggers(OnsetComputerCorporation,Bourne,Maine,U.S.).Aphotoperiodof12:12hwasmaintainedwithoverheadlightingthroughoutallexperimentsandwassupplementedwithnaturallightfromwindows.Unfertilized,fungused,anddeadeggswereremovedfromjarsatregularintervals.

HatchedfreeembryosswamupandoutofMcDonaldjarsinto1.8mcircularholdingtanks,wheretheywereheldforamaximumof12hrsbeforebeingassignedtoanexperiment.

Daysposthatch(dph)wereusedtoquantifyage,withthedayofhatchreferredtoas0dph.Sturgeoninthisstudywereclassifiedasfreeembryosfromhatchuntilthetimeofactivefeedingandlarvaethereafter(Balon,1999).Fiftyfreeembryosfromeachtemperaturetreatmentweresampledonthedayofhatchtoassesslengthathatch.Freeembryoswerefirst

presentedOtohimeFishDiet(ReedMariculture,Campbell,California,U.S.)at7dph.Feedparticlesize(range:250-1410µm;B1,B2,C1,C2)wasincreasedbasedonfishsize.Larvaeheldinthesmall0.61mdiametercirculartanksusedtoexaminetheeffectsoftemperatureandvelocity(“Velocity×Temperature”experiment)werefedtwicedailywithenoughfoodtoensureexcesswascontinuouslypresentonthebottom.Feedwascontinuouslypresentedtolarvaeinlargertanksusingautomatedbeltfeeders.Tankswerecleaneddaily.Freeembryos/larvaesampledfromexperimentswereeuthanizedwithananestheticoverdose(MS222,50mg/L),photographed(NikonD750,AFMicroNikkor60mmlens)onametricruler,andstoredinHistoPrep100%alcohol(FisherScientificCompany,Denver,Colorado).PhotographswerelateranalyzedusingImageJ(version1.50i,Bethesda,Maryland)tomeasurelength,yolksacarea,fincurl,andpresence/absenceofmelaninplugandfood.

Totallengthwasmeasuredfromthetipofthetailtotheanteriortipofthehead(Fig.12)forfishthathadnotdevelopedacaudalfilament(approximately<20.0mm)androundedto0.1mm.Forfishwithcaudalfilaments,totallengthwasmeasuredfromtheposteriorendofthenotochordtoanteriortipofthenose.Theendofthenotochordwasapproximatedifnecessarybythepointatwhichtheventralmarginofthecaudalfinmembranestopsconvergingonthenotochordandbeginstorunparalleltothecoreofthecaudalfilament(Snyder2002).Therelationshipbetweenlengthanddphwasusedtodescribegrowthrate.Yolksacareawasmeasuredtothenearest0.01mm2fromphotographsofthelateralviewoffreeembryos.Yolksacareawasonlyrecordedwhentheyolksaccouldbeclearlydistinguishedandlipidswereexcludedfromthemeasurements.Theyolksacwasconsideredtobeabsorbedwhenitwasnolongerexternallyvisibleeventhoughsomeinternalyolkmayhaveremained(Snyder2002).Therelationshipbetweenyolksacareaanddphwasusedtodescribeyolksacabsorptionrate.FincurlwasmeasuredonlarvaethatperformedintheUsprintswimchambertests.Fincurlwasquantifiedonascaleof0-4thatrepresentsthepercentageoftheoutsidemarginofthepectoralfinaffectedbyfincurl:0-nofincurl,1-<25%,2–25to50%,3–50to75%,4–75to100%outsidemarginaffected.Measurementsweremadeforbothfinsandaddedforameasureoftotalfincurl.

VELOCITY×TEMPERATURE

Theeffectsofvelocityandtemperatureonlarvaldevelopmentwereexaminedina3×2factorialexperiment.Averagevaluesofthethreevelocitytreatmentswere0,10,and21cm/s.Velocitytreatmentswerechosentoprovideacontroltreatment(0cm/s)andapproximatetherangeofvelocitiesfreeembryosmayexperienceintheUpperMissouriBasin(Braatenetal.,2008).Highervelocitiesthatmaybeexperiencedwereavoidedduetoexcessivecentripetalforcesandinabilitytomakeobservations.Averagevaluesofthetwotemperaturetreatments(nominally15and20°C)were15.3°C(SD=0.6)and21.0°C(SD=0.6).Temperaturetreatments

werechosentoapproximatethepredictedrangeofoptimalspawningtemperaturesforpallidsturgeon(Kappenmanetal.,2013).

Experimentswereconductedineighteen0.61mdiametercirculartankswitha0.46mdepth.A0.32mdiameterPVCinsertwascenteredwithinthetankstocreatea0.15mwidecircularchannelintowhichembryoswereplaced.Tankswereprovidedwithflow-throughwaterataminimumrateof5.7L/min.Inthe0cm/streatments,waterenteredthetankapproximately4cmabovethewatersurfacefromaverticallyorientatedopeningwitha13.0mmdiameter.Waterenteredthe10cm/sand21cm/streatmenttanksfromnozzles(6.2and10.6mmdiameters,respectively)locatedalongtheoutsidewallandapproximately6cmbelowthewatersurfacetoprovideaclockwisecurrent.Nozzlesweredirectedattheoutsidewalltodispersethestrongjetofwaterandlimitdamagetoembryos.WatervelocitywasmeasuredwithaMarsh-McBirneyFlo-Mate2000currentmeter(HachCorp.,Loveland,CO,U.S.)at0.6×waterdepth(‘averagevelocity’ofthewatercolumn)and3cmabovethetankbottom(‘bottomvelocity’)inthemiddleofthechannelatfourequidistantlocations(TableI).Nominalvelocities(i.e.0,10,and21cm/s)refertotheaverageofthevelocitiesmeasuredat0.6×D.Velocitytreatmentswererandomlyassignedtotanks.

Afullsetofpilotstudieswereconductedwithfreeembryosfromthefirstspawningevent(25May2017)todeterminekeybehaviors,observationtechniques,samplingtechniquesandexperimentaldesign.Observationsfrompilotstudieswereusedtosupplementresults.Inpilotstudies,observationsoccurredat800and1600hrs.However,duetolimiteddifferencesbetweenobservationsweonlyconductedobservationsat800hrswithfishfromthesecondspawningevent(13June2017).Earlyhatchembryos(hatchedwithin12hoursofthefirstobservedhatch)fromthesecondspawningeventwererandomlyassignedingroupsof10toone‘observation’andtwo‘sampling’tanksforeachtreatment.Tenembryoswereassignedtoobservationtanksand300embryoswereassignedtosamplingtanks.Fiveembryos/larvaefromeachtreatmentweresampleddailyfromoneofthesamplingtanksandtotallength(mm),yolksacarea(mm2),presenceoffood,andpresenceofpigmentplugweremeasured.Tenembryos/larvaeweresampledfromtanksinwhichembryos/larvaewereseparatedintogroupsassociatedwiththebottomandwatercolumn,withfivefromeachgroupsampled.Observationtankswereobservedfor10-15mindailybetween10:00and13:00hrsandmortality,proportionindrift/onthebottom,swimmingbehavior,andhorizontal/verticalorientationwererecorded.Mechanicalvibrationscreatedbytappingthetankandadirectedjetofwaterfromapipettewereusedtotestthedevelopmentandevolutionofescaperesponsesinembryos/larvaeafterobservationswerecompleted.Mortalitiesintheobservationtankswerereplacedafterobservationswithembryos/larvaefromasamplingtankofthesametreatment.One-twominutesofunderwatervideo(HeroSession,GoPro,SanMateo,California,U.S.)and10minofoverheadvideo(HandicamHDR-XR-150,Sony,Tokyo,Japan)ofeach

observationtankwererecordeddailyandreviewedtosupplementobservationnotes.Observationsandsamplingweretakenfrom1-30dph,dependentonsurvival.

ARTIFICIALRIVER

Freeembryo/larvalbehaviorwasobservedinalargeovalartificialriver(20mcircumference;Fig.3).TheartificialriverwasfabricatedbyHydroComposites,LLC(Stockdale,Texas,U.S.)andconsistedoftwostraightchannels(6.42mlongand1.56mwide),tworiverbends(5.81moutsidediameterand1.56mwide)andacenterwallseparatingthechannels.ChannelsarelabeledC1andC2andbendslabeledB1andB2forreference(Fig.4).Waterwassuppliedtotheriverviaare-usesystem,whichusedamixofon-sitecoldandwarmspringwater,andwasmaintainedat20.6°C(SD=0.6°C).Awoodenwingdike(0.05mlength×0.60mwidth×0.60mtall)wasplacedattheupstreamendofC2andasandbag(0.30mlength×0.72mwidth×0.15mtall)wasplaced3.4mdownstreamtocreateeddyhabitat(Fig.4).

Approximately0.06m3offoursubstratetypeswereplacedonthebottomofC1withthesizeofthesubstratesdecreasinginthedownstreamdirection:boulder(150-450mmoutsidediameter),cobble(18-45mm),gravel(5-15mm),andsand(0.3-5mm).TwoSulzerelectricmotors(Sulzer/ABSRW3022A17/6Mixers;SulzerInc.Switzerland)generatedvelocityandwereplaced0.8mabovethesubstrate,0.4mfromtheoutsidewall,and2.9mapartinC1.Therheostatpowersettingwassetat95%togeneratevelocities>2m/stodistributethesubstrate.

Waterdepthvariedfrom0.92–1.13mdependingonthepresenceandthicknessofsubstrate.Additionallargeboulderswereplacedatseverallocationsagainsttheinsidewalltocreateadditionaleddyhabitatsoverbareplasticandsandsubstrates(Fig.5).Therheostatpowersettingwasdecreasedto55%foraseriesofpilotstudiesconductedwithfreeembryosfromthefirstspawningevent(25May2017).However,theelectricmotorscausedhighmortalityandahighpitchanddecibelnoisethatmayhavedisruptednaturalbehavior.Subsequently,motorswerereplacedwithspraybarsthatspannedthewidthofthechannelandwerelocated0.5mabovethebottomand3mfromtheupstreamendofeachchannel.Afterfreeembryosfromthesecondspawningevent(13June2017)wereassignedtothevelocity×temperaturetreatments,allremainingunhatchedeggs(~5,000)wereplacedin/betweenboulder,cobble,gravel,andsandsubstrates.Approximately1000larvae(17dph)fromthefirstspawningevent(25May2017)wereplacedintheriveratthesametime.Alargemortalityeventoccurredon21June2017andtheriverwascleanedthenrestockedon22June2017with1000freeembryosfromthesecondspawningevent(5dph)and1000larvaefromthefirstspawningevent(22dph).Duetomortalityintheartificialriverandsubsequentreplacementwithlarvaefromholdingtanks,comparisonofgrowthratesamongrearingenvironmentswasnotpossible.

Embryos/larvaewereobserveddaily,with10minofobservationateachofthe10observationwindows.Observationstechniqueswerethesameasforthevelocity×temperaturetreatments.Fivetofifteenminutesofunderwatervideo(HeroSession,GoPro,SanMateo,California,U.S.)andvideotakenfromoutsidetheobservationwindows(HandicamHDR-XR-150,Sony,Tokyo,Japan)wastakendailyandreviewedtosupplementobservationnotes.Observationsweretakenfrom0-71dph.Afterthecompletionofexperiments,bottomvelocities(3cmabovesubstrate)weremeasuredwithaMarsh-McBirneyFlo-Mate2000currentmeter(HachCorp.,Loveland,CO,U.S.)every10cmlongitudinallyand6cmlatitudinallyusinga30sfixedpointaverage(velocitiesvariedtemporallyatagivenlocation).Inriverbendsthecurrentmeterwasorientedparalleltothewallsofthetankatthepointofmeasurementandfacingtheupstreamdirection.Theriverwasnotmappedduringpilotstudiesbutpointmeasurementsofvelocitieswherelarvaewereobservedonthebottomwererecorded.

SWIMCHAMBER

Ucrittestswereconductedinasmallswimchamber(5L;30.0×7.5×7.5cmtestsection;LoligoSystems,Tjele,Denmark)toestimatemaximumaerobiccapacityandUsprinttestswereconductedinalargeswimchamber(185L;87.5×25.0×25.0cmtestsection)toestimatemaximumanaerobiccapacity(Brett,1964;Starrsetal.,2011).Swimchamberswereequippedwithamotorandvariablefrequencydriverthatallowedrapidandprecisevelocityadjustments.AMarsh-McBirneyFlo-Mate2000currentmeter(HachCorp.,Loveland,CO,U.S.)wasusedtocalibratevelocitysettingsbytaking30sfixedpointaveragedmeasurementsat0.6timesthewaterdepthforeachvelocitysetting.Flowstraightenerslocatedupstreamofthetestsectionprovidedrectilinearmicro-turbulentflowandanapproximatelyuniformvelocityprofile.Swimchambersweresuppliedwiththesameflowthroughwellwaterthatsuppliedtheholdingtanksandwatertemperaturedifferedlittle(±0.5°C;range)amongholdingtanksandswimchambers.Ucrittestsoccurredat21.1±1.4°CandUsprinttestsat19.8±1.1°C.LarvaefromthesecondspawningeventwereusedfortheUcrittestsandwereheldina1.8mcirculartanksat21.1±0.6°C.Ucrittestswereconducteddailybeginningon6dph.However,embryoswerenotabletocompletetheacclimationperiod(15minat5cm/s)until10dayspost.Subsequently,tenlarvaeweretestedeveryotherdayuntil32dph.LarvaefromthefirstspawningeventwereusedfortheUsprinttest(64-78dph)andwereheldina1.8mcirculartankandtheartificialriverat20.5°C(SD=0.6°C).

Testsbeganwitha15minacclimationperiodat5cm/sfollowedbya5cm/svelocityincreaseevery5minintheUcrittestandevery15sintheUsprinttest.Motorswereturnedoffwhenalarvaebecameimpinged,whichwasdefinedashavinggreaterthanathirdoftheirbodyrestingonthedownstreamgratefor3s.Aftera2minrest,thetestresumedatthevelocityincrementwhereimpingementoccurredintheUcrittestwhereasvelocitywasresetto

10cm/sintheUsprinttests.Thelarvaewasconsideredfatiguedandthetestendedafterthethirdimpingement(Allenetal.,2006;Verhilleetal.,2014).UcritandUsprintvalueswerecalculatedusingtheformulaprovidedbyBrett(1964):

(1) Ucrit,Usprint=Ui+[U(ti×t-1)]whereUiisthepenultimatevelocity(cm/s),tiistheamountoftime(s)thefishswaminthefinalincrement,tisthetimeincrementbetweenvelocityincreases(300sand15s,respectively)andUisthewatervelocityincrement(5cm/s).Onlythehighestrecorded

Ucrit/Usprintvalueoutofthethreeattemptswereincludedinthedatasetusedforanalysis.

DATAANALYSIS

Multipleregressionwasusedtoexaminerelationshipsamongresponsevariables(length,yolksacarea,UcritandUsprint)andexplanatoryvariables(seeTableIIforlistofvariablesexamined).Interactionswereincludedinmodelsiftheywerehypothesizedtobebiologicallymeaningfuland/orpatternswereobservedinexploratorygraphs.Extra-sumofsquaresF-testswereusedtodeterminetheinclusion/exclusionofacovariatefromtheinferentialmodel(RamseyandSchafer,2002),withcovariateswiththeleaststatisticalsupportremovedfirst.Logisticregressionwasusedtoexaminerelationshipsamongthepresenceoffood,velocity,temperature,length,andage.Thesamemodelselectionprocessusedforlinearregressionwasusedforlogisticregressionwithlikelihoodratiotestsusedtoassessstatisticalevidence(RamseyandSchafer,2002).Lengthandageeffectswereexaminedinseparatemodelsduetothecorrelationofthesevariables.Age,cumulativethermalunits,andlengthattheonsetandconclusionofdevelopmenteventsarepresented(TableIII).

Anaturallogtransformation(ln)wasappliedtotheabsoluteUcrit(cm/s)valuesduetodatabeingseverelypositivelyskewed.RelativeUcrit/Usprintvalues(bodylengths/s)werecalculatedbydividingabsoluteUcrit/Usprintvalues(cm/s)byfishlength(cm).DifferencesinrelativeUsprintbetweentankswasexaminedwithaWelchtwosamplet-test(RamseyandSchafer,2002).

Observationaldatawasnotstatisticallyanalyzedduetoitssubjectivity,lackofnormality,lackoflinearity,andlackofreplication.Instead,thefirstobservationofnewbehaviors,dominantbehaviors,andshiftsinbehaviorsarereported.

Assumptionsofhomogeneityofvariance,normality,linearity,andmulticollinearityforregressionanalyseswereassessedusingplotsofresidualsversusfittedvalues,normalquantilequantileplots,plotsofresponsevariablesversuscontinuousexplanatoryvariables,andvarianceinflationfactors,respectively.Allassumptionswereadequatelymet.Regressionwas

performedinprogramRversion3.2.3(RCoreTeam2015)usingthelmfunction.

RESULTS

VELOCITY×TEMPERATURE

EmergenceandDevelopmentalStages

Massemergenceoffreeembryosfromthe1stspawningeventoccurredat6dayspostfertilization(dpf;97CTU;incubatedat16.1°C).Massemergenceofembryosfromthesecondspawningeventoccurred7dpf(110CTU)foreggsincubatedat15.5°Cand4dpf(82CTU)foreggsincubatedat20.5°C.Embryoshatchedat15.5°Cwerelonger(8.2mm)thanatthosehatchedat20.5°C(7.9mm;t81=5.5,P<0.0001).Swimupbehaviorwasobservedimmediatelyafterhatch.

Presenceoffoodinstomachsat15°Cwasfirstobservedat18dph(275CTU)inthe0cm/sand11cm/streatmentsand19dph(291CTU)inthe20cm/streatment.Theproportionoflarvaewithfoodintheirstomachsgenerallyincreasedwithdphbutremainedlessthan0.6by30dph.At20°Cthepresenceoffoodwasfirstobservedat10dph(205CTU)andfoodwaspresentinallsampledlarvaeby13dph(268CTU).However,theproportionoflarvaewithfoodintheirstomachsdecreasedmarkedlyat19dph(398CTU)andsubsequentdays.Logisticregressionindicatedtherewasstrongevidencefortherelationshipbetweenageandpresenceoffoodtodependontemperature(χ2=83.2,df=1,P<0.0001;TableIV,Fig.6).Logisticregressionindicatedtherewasnoevidenceforarelationshipbetweenpresenceoffoodandvelocityinbothage(χ2=2.47,df=2,P=0.29)andlength(χ2=3.35,df=2,P=0.19)models.

Lengthwasamoreprecisepredictorofthepresenceoffood,withpresenceoffoodfirstobservedatanaveragevalueof18.8mmat15°Cand19.6mmat20°Candthesmallestindividualsobservedwithfoodpresentinthestomachwere18.3mmand18.4mmat15and20°C,respectively(TableIII).Therewasstrongevidencefortherelationshipbetweenlengthandpresenceoffoodtodependontemperature(χ2=17.97,df=1,P<0.0001;Fig.7).Foodwasnotpresentinanylarvaethathadnotexpelledtheirmelaninplugorthathadexternallyvisibleyolksac.Subsequently,sturgeonareclassifiedasfreeembryosbefore18and10dphinthe15and20°Ctreatments,respectively,andlarvaethereafter.

Length

Aquadraticrelationshipbetweenlength(mm)anddaysposthatch(dph)wasobservedwiththerateofgrowthbeinggreatestdirectlyafterhatch,graduallydecreasing,andeventuallybecomingnegativeat22(337CTU)and13dph(268CTU)inthe15and20°Ctreatments,

respectively(Fig.8).Thenegativegrowthratesmayhaveresultedfromlarvaenotfeedingefficientlyontheprovidedfood.Thus,onlygrowththatwassustainedbyyolksacutilizationwasmodeledinregressionanalysis.Theexpulsionofthemelaninplugwasusedtoindicateyolksacutilizationwascomplete.Melaninplugswerefirstobservedbeingshedat15(230CTU)and8dph(163CTU)inthe15and20°Ctreatments,respectively(TableIII).Thesheddingofthemelaninplugdidnotdifferamongvelocitytreatments.Allmelaninplugsinsampledlarvaewereshedby18(275CTU)and10dph(205CTU)at15and20°C,respectively(TableIII).Thus,areduceddatasetfromemergenceto18and10dphforthe15and20°Ctreatments,respectively,wasusedforlengthanalysis.

Therewasstrongevidenceforanassociationbetweengrowthrateandtemperature(i.e.temperature×ageinteraction;F2,609=311.3,P<0.0001),withthegrowthratebeingsignificantlygreaterat20than15°C(Fig.8).Therewasnoevidencethatgrowthrate(F2,606=1.1;P=0.32)orlength(F2,606=2.6;P=0.11)wasassociatedwithvelocity.

YolkSacArea

Absenceofexternallyvisibleyolksacswerefirstobservedat15(230CTU)and9dph(184CTU)inthe15and20°Ctreatmentsandallsampledspecimenslackedyolksacsby17(260CTU)and10dph(205CTU),respectively.Analysiswasperformedonareduceddatasetforfreeembryosfromemergencetowhenallsampledspecimenslackedexternallyvisibleyolksacs.Anapproximatelylinearrelationshipwasobservedbetweenyolksacareaandage(dph).Therewasnoevidenceforarelationshipbetweenvelocityandyolksacarea(F2,508=2.4,P=0.09).Yolksacareaandtherateofdepletionwasrelatedtotemperature(F2,510=369.7,P<0.0001).Therateofyolksacdepletionwas0.29mm2/dphgreaterat20°C(0.71mm2/dph,95%CI=0.65,0.76)thanat15°C(0.42mm2/dph,95%CI=0.41,0.44;Fig.9).

Anapproximatelylinearrelationshipwasobservedbetweenyolksacareaandlength.Therewasnoevidenceforarelationshipbetweenvelocityandyolksacarea(F2,508=0.5,P=0.64).Therewasstrongevidencefortherateofyolksacdepletion,relativetolength,todependontemperature(F1,508=45.6,P<0.0001).Yolksacutilizationresultedinagreaterincreaseinlengthat20°Cthanat15°C(Fig.10):a1.00mm2reductioninyolksacarearesultedina1.42mmincreaseinlength(95%CI=1.36,1.49)at15°Ccomparedtoa1.89mmincreaseinlength(95%CI=1.64,2.24)at20°C.

Behavior

Individualfreeembryo/larvalbehaviorandbehavioramongindividualswashighlyvariable.Thus,resultsfocusonwhenbehaviorwasfirstobserved,behaviordisplayedbythemajorityoffreeembryos/larvae,andnotabletemporalshiftsinbehaviors.Swimupbehaviorwastheonlyswimmingtypeobservedimmediatelyafterhatchuntil10dphinthe15°Ctanksand5dphinthe20°Ctanks.Generally,contactwiththebottomorsidesofthetanksinitiatedverticalswimupbehaviorandcontactwiththewatersurfaceresultedindriftdownbehavior.Thefrequencyofswimupbehavior(i.e.timebetweenconsecutiveswimupbehaviors)wasnotablyhigherinthe20°Ctanksthanthe15°Ctanksandhigherinthe10cm/sand21cm/stanksthanthe0cm/stanks.Thehigherfrequencyofswimupbehaviorinthe10cm/sand21cm/stanksat20°Cresultedinthemajorityoftheembryosbeinglocatedatthesurfacecomparedtoembryosbeingdistributedthroughoutthecolumnintheothertreatments.Orientationoftheswimupbehaviorbecamelessverticalandmorehorizontalastheembryosdevelopedandconcurrentlythespeedofverticalmigrationslowed.Themajorityofembryosdevelopedhorizontalorientationby11dphin15°Ctanksand5dphin20°C.Horizontalorientationwaspredominantlypositiveforembryos/larvaeorientedonthebottomwhereasembryos/larvaeinthewatercolumnwerealmostequallypositivelyandnegativelyorientedfortheremainderoftheexperiment.

Embryoswerefirstobservedorientatingonthebottom11dphat15°Cand6dphat20°Cinallvelocitytreatments.Thiswasassociatedwithatransitionfromswimup-driftbehaviortosteadysustainedswimming.Theproportionofembryos/larvaeonthebottominthe10cm/s×20°Cand21cm/s×20°Ctreatmentsrosetopeaksof0.9and0.5by9dph,respectively,thenfluctuatedbetweenthepeakand0.0fortheremainderoftheexperiment.Consistenttrendsintheproportionofembryos/larvaeonthebottomwerehardtodiscernintheothertreatmentsandtheproportionfluctuateddrasticallyonadailybasis,butwasgenerallylessthan0.5.Differencesinyolksacarea,length,presenceoffood,andtheexpulsionofthemelaninplugwerenotobservedamongembryos/larvaesampledonthebottomversusthosesampledinthewatercolumn.Embryosorientedonthebottomwerefirstobservedholdingpositionagainstthecurrentinthe10cm/streatmentsat11dphinthe15°Ctanksand6dphinthe20°Ctanks.Embryoswereabletoholdpositionforbriefperiodsoftimeonthebottominthe21cm/streatmentsat12dphat15°Cand7dphat20°Cusingareasoflowvelocityneartheinsidewall.Whenwatervelocityonthebottomexceededswimmingabilitiesandresultedindownstreammovement,larvaewouldswimupintothewatercolumnandgobackintodrift.Larvaewerenotobservedmakingupstreamprogresswhileinthewatercolumnandtailbeatfrequencywasgenerallylowerforlarvaeinthewatercolumnvs.thoseattemptingtoholdpositiononthebottom.

Startletotouchassociatedwithsamplingwasobserved1dphatbothtemperatures.Embryosdisplayeda‘C-type’startleresponse(arapidmovementofthebodyintotheshapeofa‘C’’;Blaxter&Batty,1985;Hardy&Litvak2004)followedbyaburstofswimmingthatlastslongerthanbehaviornotassociatedwithadisturbance.A‘C-type’startletomechanicalvibrationwasfirstobserved9-11dphat15°Cand4dphat20°C.Consistentstartleresponsestoajetofwaterwereobservedat10-11dphat15°Cand3-5daysat20°C;arelationshipbetweenvelocityandastartleresponsewasnotobserved.Themostprevalentresponsetothejetofwaterwastoorientpositivelytoitandswimagainstit,althoughfishoccasionallyswamawayfromthejet.Fishonthebottompressedtheirbodiesagainstthebottomandquicklyswambacktothebottomifthejetdisplacedthem.Priortoastartleresponsedeveloping,thejetofwaterwouldresultinfishceasingswimmingactivityandgoingintopassivedriftforashortperiodoftime.Thisresponsewasoccasionallyobservedafterastartleresponsedevelopedandwasmostprevalentinthe10and21cm/streatments.

Mortality

Mortalitywaslow(≤10%)in20°Cobservationtanksup16dph,atwhichpointmortalityroseexponentiallyresultingin100%mortalityby21dphinbothobservationandsamplingtanks(Fig.11).Mortalityinthe0cm/s×15°Cand10cm/s×15°Ctanksfirstoccurred4daysafteremergenceanddailymortalityrateaveraged20%and7%,respectively,between4-18dph.Mortalityratewaslow(≤10%)19-27dphbeforerisingto50%and30%by30dphinthe0cm/s×15°Cand10cm/s×15°Ctanks(Fig.11).Mortalityrateinthe21cm/s×15°Ctankwaslow(≤10%)fromemergenceto29dphbutroseto50%on30dph.

ARTIFICIALRIVER

Complexflowconditionsanddiversesubstratetypeswerecreatedintheartificialriverthatapproximatedmanyhabitattypespresentinthenativewatersofpallidsturgeon.Largersubstrates(boulder,cobble,andgravel)wereconfinedtoC1andB1whilesandwasdistributedtolocationsthroughouttheriver(Fig.5).Bareplasticwasthemostprevalentsubstrate(73.7%;32.4m2)followedbysand(9.6%;4.2m2),cobble(8.6%;3.8m2),gravel(5.0%;2.2m2),boulder(3.4%;1.5m2),andamixtureofgravelandsand(0.7%;0.32m2).ThelargestdepositsofsandsoccurredatthedownstreamendofC1andformedintosmallsanddunes(maximumheight15cm).Finesandofatancolorcollectedalmostexclusivelydownstreamofthesandbag(Fig.4-5,coarsersandwasadarkgrey).Averagebottomvelocitywas6.4cm/s(SD=6.2)andrangedfrom-12.2cm/sto24.4cm/s.Areasofhighvelocityexistedattheupstreamendsofeachchannelandlowvelocityareasexistedattheupstreamendofeachriverbendalongtheoutsideedge(Fig.12).Thewingdikecreatedaneddywitha1.43m2bottomfootprintandmultiplesmallereddieswerecreatedbehindtheboulders,sandbag,alongtheinsidewall.

Freeembryosswamupimmediatelyafterhatchregardlessofthesubstratetheyhatchedin.Someembryoswereobservedgettingstuckintheinterstitialspacesamongthecobbledirectlyafterhatchforthedurationoftheobservationperiod(10min).However,thisappearedtobearesultofadifficultyadjustingorientationandgettingoutofthetightinterstitialspaces.Swimupbehaviorwasobservedexclusivelyuntil5dph.Contactwiththebottomorsidesofthetankusuallyinitiatedswimupbehaviorandcontactwiththewatersurfacegenerallystimulateddriftdownbehavior.Embryoswerepredominantlyinthelowerhalfofthewatercolumn0-1dph(≤.5m)butweredistributedthroughouttheentirewatercolumnthereafter.After5dphorientationbegantobecomemorehorizontalandasteadysustainedswimmingpatternwasobserved.

Embryoswerefirstobservedonthebottomon7dphandtheproportionofembryos/larvaeonthebottomreachedapeakofapproximately0.9on10dphandsubsequentlyfluctuatedbetween0.4and0.9.Fishwereobservedinthewatercolumnthroughoutthedurationoftheexperiment.Embryos/larvaepredominantlysettledontheplasticsubstrateinC2andB2(Fig.4).From7-10dphembryoswereoftenobservedonthesandinfrontofandbehindthewingdikeandthesandandgravelattheupstreamedgeofthebouldersinC1butwererarelyobservedintheseareasafter10dph(Fig.4-5).Duringthistime(7-10dph)oneofthelargestcongregationofembryos(100-200)wasobservedintheeddylinedownstreamofwingdike.Embryosremainedonthebottominthisareadespiteitbeingturbulentandflowdirectionchangingfrequentlyanddrastically.

After10dphlarvaewereassociatedalmostexclusivelywithplasticsubstrateinC2andB2withtheexceptionofthesandbelowthesandbagandthesurfacesofthebouldersinC1(Fig.4-5).Embryos/larvaewereneverobservedsettlingonthecobbleinC1andrarelysettledonthelargeareaofsandbelowthecobbleonthedownstreamendofC1(Fig.5).Touchingthecobblesubstrateorswimmingclosetoitgenerallyresultedinembryos/larvaeswimminghigherinthewatercolumn.

Embryos/larvaegenerallyselectedareaswithvelocitiesrangingfrom-5–15cm/s.Eddyhabitatwasnotpreferentiallyselectedoverhabitatinthemaincurrent.Areasofhighvelocity(>20cm/s)wereavoidedbyembryos/larvaethroughoutthedurationoftheexperiment.Larvaeinthecurrentswamvigorouslytoholdpositiononthebottom,butwhenwatervelocityexceededswimmingabilitiestheygenerallyswamupintothewatercolumnandswimmingintensitydecreased.Larvaewereneverobservedmakingsustainedupstreamprogresswhileinthewatercolumnoronthebottom.Loosecongregationsofembryos/larvaewereobservedbutcontactwitheachothergenerallyinitiatedasmallstartleresponse.Contactofsmallerfishfromthesecondspawningeventwithlargerfishfromthefirstspawningeventgenerallystimulatedswimupbehaviorforthesmallerindividual.Foodavailabilityappearedtohavea

strongeffectonlarvalswimmingbehavior.Foodwasexperimentallywithheldfor1.5dayson7/30(61dphlarvaefromfirstspawningeventand44dphlarvaefromsecondspawningevent)andresultedin>90%offishindownstreamdriftinthewatercolumn.Whenalargeamountofnegativelybuoyantfoodwasadded,>90%offishsettledtothebottomwithin5min.

SWIMCHAMBER

Atotalof117Ucrittestsand75Usprinttestsweresuccessfullycompleted.Larvalpallidsturgeonshowedhighmotivationtoswimintheswimchamber,withonlyasinglelarvaeinanUcrittestnotswimmingduringtheacclimationperiod(removedfromdataset)andalllarvaeinUsprinttestcompletingtheacclimationperiod.Larvaedidnotshowapreferenceforswimmingonthebottom,rarelystationheldonthebottom,andwereobservedswimmingthroughouttheswimchamber.Mostfishperformedbestontheir1stattempt:44%/56%achievedtheirhighestUcrit/Usprintvalueonthefirstattempt,26%/29%onthesecond,and30%/15%onthethird.

RegressionanalysisprovidedevidenceforrelationshipsbetweenUcrit,ageandlengthandbetweenUsprint,length,andholdingenvironment(TableIV,Fig.13-15).InbothUcritandUsprinttests,lengthhadthelargesteffectonswimmingabilities(TableIV).AbsoluteUcrit(cm/s)waspositivelyrelatedtolength(P<0.0001)andage(P<0.0001;Fig.13)whereasrelativeUcrit(bodylengths/s)wasnegativelyrelatedtolength(P<0.0001)andage(P<0.0001;Fig.14).Ageandlengthwerehighlycorrelated(0.86)amongtheyoungerfishintheUcrittestsbutcorrelationdecreased(0.24)amongtheolderfishtestedintheUsprinttestsandtherewasnoevidenceforarelationshipbetweenageandabsoluteUsprint(P=0.18)orrelativeUsprint(P=0.58).TherewasevidenceforholdingenvironmentbeingassociatedwithabsoluteUsprintinboththeage(P=0.02)andlength(P=0.007)models,withUsprintvaluesbeinganaverageof5.3cm/s(95%CI:1.2,7.5)greaterforfishraisedintheartificialriverthanina1.8mcirculartankafteraccountingforageand4.4cm/s(95%CI:1.0,9.7)afteraccountingforlength(Fig.15).Similarly,therewasstrongevidenceforarelationshipbetweenrelativeUsprintandholdingenvironment(P=0.007),withthemeanUsprintoffishfromtheartificialriver(4.9BL/s)being0.5BL/s(95%CI:0.1,0.8)greaterthanthemeanUsprintoffishfromthe1.8mcirculartanks(4.5BL/s).TherewasnoevidenceforarelationshipbetweenfincurlandUsprintinanyofthemodels(P>.15,TableIV).

DISCUSSION

Integratinginformationonpallidsturgeonlarvalbehavior,swimmingabilitiesandhabitatselectionwithenvironmentalvariablessuchastemperature,substrate,andvelocitywillallowustore-evaluatethelarvaldrifthypothesisandbetterunderstandtheearlylifehistoryrecruitmentbottleneck.Inthisstudy,wesawevidencethatlarvaldriftmaycontinueafter

exogenousfeedingbegins,resultinginlongerdriftdistances.Temperaturehadastrongeffectontherateofdevelopmentandresultswerecongruentwithpreviousstudies(Kynardetal.,2002,2007,Webbetal.,2007).Testsandobservationsofswimmingabilitiesindicatethatlarvalpallidsturgeonarerelativelyweakswimmersanddriftislikelycurrentdominatedearlyindevelopmentandtheabilitytomoveupstreamisseverelylimited.Duetologisticrestraintsandthecomplexityofaccuratelyaccountingfordriftpathwaysandvelocities,driftspeedswerenotquantitativelymeasured.However,importantexperimentalprotocolsweredevelopedthatwillfacilitateandenhancefuturestudiesattheBozemanFishTechnologyCenter.Additionally,aphotographicguidetolarvaldevelopmentwasdevelopedthatwillfacilitatethedeterminationoflarvalageinthefieldandhelpstandardizelengthandyolksacmeasurements.Althoughresultsaddtoourunderstandingoflarvaldriftanddevelopment,theycallintoquestionpartsofthelarvaldrifthypothesisanddemonstratethatfurtherresearchisneededtounderstandtherecruitmentbottleneck.

Pallidsturgeonarebelievedtospawnovercoarsesubstrates(boulder,cobble,gravel)andadhesiveeggsattachtothesubstrate(Dettlaffetal.,1993;U.S.GeologicalSurvey,2007;DeLonayetal.,2009,2014,2016).Timetohatchwashighlycorrelatedtotemperatureandmasshatchwasobservedbetween3-7daysafterfertilization,whichagreeswithobservationsofpreviousstudies(DeLonayetal.,2016).Atlanticsturgeon(Acipenseroxyrinchus),shortnosesturgeon(A.brevirostrum)andwhitesturgeon(A.transmontanus)allseekcovershortlyafterhatchwhenappropriatesubstratesareprovidedbutareobserveddisplayingdriftbehaviorwhensubstrateswerenotprovided(RichmondandKynard,1995;KynardandHorgan,2002;Kynardetal.,2002;McAdam,2011).However,observationsofembryoshatchingoutofvarioussubstrates(sand,gravel,cobble,andboulder)confirmsreportsofswimupbehavioroccurringdirectlyafterhatchforpallidsturgeon(Kynardetal.,2002,2007).

Weobservedembryosdriftinginthelowerhalfofthewatercolumn(<0.5m)from0-1dph;thereafter,embryos/larvaewereobserveddriftingthroughoutthewatercolumn.Kynardetal.(2002,2007)observedembryosnearthebottomfrom0-5dph,intheupperwatercolumnfrom~6-9dph,andnearoronthebottomthereafter.However,theseexperimentswereconductedinalowvelocityenvironment(2cm/s)withinasmalltestingapparatus(300cmdepthx15cmdiameter).Giventhatcontactwithsurfacesgenerallyelicitaswimupresponse,thesmalldiametertesttubemayhaveresultedinartificialresults.Thisislikelythecaseinalllaboratorystudies,wheretherelativesurfaceareaoftanksinrelationtowatervolumegreatlyexceedstheratioofbottomsurfaceareatowatervolumeinnaturalenvironments.Fieldstudiesandcollections(BraatenandFuller,2002,2003,2004,2005;Braatenetal.,2008,2012a)indicatethatembryosprimarilydriftclosetothebottom.Inthedeeper,swifter,andmorehydraulicallycomplexenvironmentsoftheMissouriandMississippiRivers,itmaybeharderforembryostomoveupinthewatercolumnandtheirlocationmaybe

primarilydeterminedbythecurrent(Braatenetal.,2008).Additionally,giventhatfreeembryosarenegativelybuoyant,swimupwhentheycontactasurface,arerelativelyweakswimmersearlyindevelopment,andeventuallysettleonthebottom,itisreasonabletohypothesizethatmostembryosaretransportedindriftnearthebottom.Locationinthewatercolumnhasalargeeffectondriftdistance,asvelocitymappingintheMissouriRiverbelowFortPeck,Montana,hasshowndriftnearthebottomcanbetwiceasslowasdriftinthewatercolumn(MarotzandLorang,2017).

Embryonicswimmingabilitieswereveryweakanddriftatthisstageislikelycurrentdominated.Braatenetal.(2008)suggestsdriftspeedsaresimilartocurrent,asthishasbeenobservedinothersturgeonspecies:Beluga(Husohuso),Russian(Acipensergueldenstaedti)andstellatesturgeon(A.stellatus)driftatabout80-90%oftherivervelocity(Khoderevskaya,2002,citedbyGisbertandRuban,2003).Theobservedburstup–driftdowncyclicbehaviormayhaveevolvedtokeepembryosfromgettingstuckininterstitialspacesinthesubstrate,facilitateexitingeddyhabitat,andenhanceentrainmentinthemaincurrent.Swimupbehaviorinsmalleddiesbehindbouldersandthesandbagintheartificialriverquicklyremovedembryosfromtheseretentionareasandbackintothecurrent.Additionally,embryoswereoftenobservedceasingswimmingactivityafterexperiencinganabruptincreaseinwatervelocity,whichmaybeanadaptiontofacilitateentrainmentinthemaincurrent.However,manyembryoscaughtinthelargeeddybelowthewingdikespentconsiderabletimethereandtheirabilitytoreduceretentiontimeinlargerbackwaterareasremainsunclear.Fieldstudiesindicatelarvaedriftforlongdistances(245-530km)andmeasureddriftratesindicatelarvaedriftatratesslightlyslowerthanthemaincurrent(66-70cm/sversus72cm/smeanwatervelocity;Brattenetal.,2008,2012a).However,givenlimitationsonthevolumeandlocationofwatersampled,itislikelytheseresultspertaintothefastestdriftingindividuals(MarotzandLorang,2017).Duetolowrecapturerates,thefateofthevastmajorityoflarvaeisunknown(Braatenetal.,2008,2012a).However,recaptureofjuvenilesfromthesestudiesindicatethatsomeareabletodevelopbeforeendingupinreservoirs(Braatenetal.,2012b).

Velocitymappingof338kmoftheMissouriRiverdownstreamofFortPeck,Montana,andsimulateddriftpathwaysindicatethatmostdriftingparticlesinthethalwegwouldbedispersedintolowvelocityretentionareas(i.e.backwaters,low-velocityrivermargins,andsidechannels)inlessthan3.1km(MarotzandLorang,2017).Wedidnotobservebehaviorthatwouldallowembryostoquicklyexitlargebackwaterorlowvelocityareasfarfromthemaincurrentandlarvaldriftwouldbesubstantiallyslowedbyenteringtheseareas.Flowmodelinganddriftsimulationsneedtobefurtherassessedwithempiricalobservationsofdriftingparticlesandembryos/larvaeinordertounderstandhowearlylifeswimmingbehavioraffectsdriftdistancesandverifypredicteddriftdistances.

Presenceoffood,whichsignifiesthetransitionfromfreeembryostolarvae,firstoccurredat275CTU(18dph)and205CTU(10dph)at15and20°C,respectively.Whilethetransitionat20°Ccloselymatchesthe200CTUthresholddescribedbyKynardetal.(2007),thepresenceoffoodwasnoticedmuchlaterat15°C.Becauseweobservedlarvaeat15°Chavingdifficultyfeeding,itispossiblethatwemisidentifiedthistransition.However,observationsoftheabsenceoftheyolksacandmelaninplug,whichwerealwaysobservedbeforefoodwasobserved,didnotoccuruntil230CTU.Thisindicatesdevelopment,relativetoCTU,occurredataslowerrateat15°Cthanatwarmertemperatures(KynardandParker,2005;Kynardetal.,2002,2007),whichisconsistentwiththeloweryolksacutilizationefficiencyweobservedat15°Ccomparedto20°CintheVelocityxTemperatureexperiments.Theseobservationsarelikelyduetotheeffectsoftemperatureonenzymeactivity,metabolicrate,growth,anddevelopmentanddeserveacloserphysiologicalexamination(Fry,1971).Congruentwithresultsfrompreviousstudies,lengthwasthemostconsistentpredictoroflarvaldevelopment,withfoodpresentinlarvae18-20mminlength,regardlessoftemperatureofage(Snyder,2002;Kynardetal.2002,2007;Braatenetal.,2002,2008).Thesefindingsshowartificiallylowhypolimneticreleaseswilldelaydevelop,increasedriftdistances,andultimatelydecreaseembryosurvival.

Embryoswerefirstobservedsettlingonthebottomat11dph(168CTU)at15°Cand67dphat20°C(122-142CTU).Theseobservationscloselyprecededtheexpulsionofthemelaninplugandtheinitiationofexogenousfeeding.Duetodailyfluctuationsinsettlingbehaviorandaninabilitytodiscernwhenmostembryoshaddevelopedsettlingbehavior,werecommendusingtheagewhentheyolksacwasabsorbedinalllarvae(17and10dphat15and20°C,respectively)asaconservativeproxyofthedurationofdevelopmentneededtodevelopsettlingbehavior.This‘driftduration’closelymatchespreviouslyreportedranges(Kynardetal.,2007;Braatenetal.,2008,DeLonayetal.,2016).Theabsorptionoftheyolksacwasaccompaniedbychangesinbodyshapethatfacilitatedswimmingonthebottom(i.e.aflatventralsurfaceandmorefusiformshape).Comparisonoflength,yolksacarea,andpresence/absenceoffoodandthemelaninplugbetweenembryos/larvaesampledonthebottomandinthewatercolumndidnotrevealanydifferences,indicatingthatembryos/larvaewerelikelycyclingbetweensettlingonthebottomanddriftingbehavior.

Weobserveddriftinsomeportionofoursampleuntil30dphintheVelocityxTemperaturetreatmentand71dphintheartificialriver(i.e.theendofobservations).Kynardetal.(2007)suggestthatlarvaedon’tmigratedownstreamaftertheysettletothebottomafter~200CTUofdevelopment,basedonbehaviorofothersturgeonspecies(Kynardetal.,2002;KynardandHorgan,2002;Zhuangetal.,2002;KynardandParker,2005).Theyalsonotethattheyobservedyearlingjuvenilesdispersedownstream(B.Kynard,E.Parker,D.PughandT.Parker,unpubl.data)andthatitisunlikelythatyoungerfishwouldalsobedispersing.

However,larvaldriftstudiesintheUpperMissouriRiverindicatethatsomeexogenouslyfeedinglarvaeremainindrift.ResultsfromBraatenetal.(2012a)showsimilardriftspeedsinthemainstemUpperMissouriamongcollectedlarvaeaged5-15dph,althoughcollectionofolderindividualsbecamerarerasdriftdistanceincreased(19.6°C).Similarly,Braatenetal.(2008)observedoverlapindriftspeedsof1-17dphembryos/larvaeinanaturalside-channeloftheUpperMissouri(17.8–24.5°C).Thetimepostreleasethatlarvaewerecollectedwasmostvariablefor17dphlarvaeanddriftspeedslowest(0.20m/sslowerthanthemeanwatercolumnvelocity).Theseresultscouldbeexplainedbylarvaecyclingfromsettlingonthebottomandswimmingupintodrift,whichwasobservedinourlaboratorysetting.

Steffensonetal.(2018)reportsdownstreamdispersalfromstockinglocationsforage-0(mean:153dph,range:64-202)toage-6hatcheryrearedpallidsturgeonintheLowerMissouri.TheLowerMissouriisdefinedasthe1305kmofundammedriverbelowGavinsPointDam,SouthDakota,totheconfluencewiththeMississippi.Thissegmenthasbeenhighlychannelizedfornavigationandmuchofthenaturallowvelocityandshallowdepthhabitathasbeeneliminated(Galatetal.,2000;ErwinandJacobson,2015).Generally,age0-6fishwererecapturedwithin30riverkilometers(rkm)downstreamfromstockinglocationsbutmuchlongerdistancesovera1,000rkmdownstreamwerealsoobserved(Steffensenetal.,2018).DownstreammovementofstockedjuvenileshasalsobeenobservedintheYellowstoneRiver(Jaegeretal.,2007),PlatteRiver(Snooketal.,2002),LowerMissouriRiver(Wilsonetal.,2008)andtheUpperMissouriandMariasRivers(Oldenburgetal.,2011).However,upstreammovementhasalsobeenobservedamongage-1andolderstockedfish(Jordanetal.,2006,Klumbetal.2012).Furtherresearchisneedtoidentifymovementpatternsofyoungpallidsturgeon,especiallydirectlyafterinitialsettling.Ourobservationsindicatemovementispredominantlydownstream0-71dphandtherateofdownstreammovementislikelyassociatedwithhabitatavailability.

Verylittleisknownaboutpallidsturgeonhabitatduetothecomplexityofstudyingspeciesinlargeturbidrivers,therarityofthespecies,andverylimitedanecdotaldataonhabitatuseinnaturalsystemsbeforedamsalteredavailablehabitat(Jordanetal.,2016).Adultandjuvenilesturgeonareoftenassociatedwithsandysubstratesindeepswiftwaterinthemainchannel(BramblettandWhite,2001;Jordanetal.,2006,Gerrityetal.,2008).YoungoftheyearpallidandshovelnosesturgeonintheMiddleMississippiRiver(320riverkilometersofchannelizedriverbetweentheconfluencesoftheOhioandMissouriRivers)werefoundtobeassociatedwithsandsubstratesinlowvelocity(~10cm/s)channelborderareas(Phelpsetal.2010).Sandwasthesecondmostcommonlyselectedsubstrateintheartificialriveraftertheplastictankbottom.Wehypothesizethatplasticwasselectedduetoitsgreaterrelativeavailabilityandfeedingefficiencybeinggreatestonthisflatsmoothsurface.Notably,weobservednolarvaesettlingonthecobblesubstrate.Near-boundaryturbulenceassociatedwith

cobblemayhaveaffectedfishorientationandstabilityanddeterredlarvaefromsettlingintheseareas(TriticoandCotel,2010;Silvaetal.,2012).

SimilartoPhelpsetal.(2010),weobservedlarvaesettlinginlowvelocityareas(<15cm/s)andavoidingorswimmingupintodriftwhenvelocitiesexceededthisthreshold.SelectedhabitatappearedtobecloselyassociatedwithestimatesofmaximumsustainedswimmingvelocitiesfromUcrittests.Ifthisassociationholdsforolderfish,Ucrittestscouldbeausefultooltopredictwhenpallidsturgeontransitionfromlow-velocitychannelborderhabitatintothemainchannel.Adamsetal.(2003)reportsmeanUcritvaluesof36cm/sforpallidsturgeon180dph,indicatingaslowincreaseinswimmingabilitieswithage/length(meanlength:21.4cm).SimilarUcritvalueshavebeenreportedforothersturgeonspeciesandindicatethatsturgeonarerelativelyweakswimmerscomparedtootherfamiliesoffish(KatopodisandGervais,2011;Verhilleetal.,2014).Adamsetal.(2009)reportssimilarsprintingabilities,relativetosize,foryoungoftheyearpallidsturgeonranginginsizefrom13.0-16.9cm(40-70cm/s)and17.0-20.5cm(55-70cm/s).Thesevelocitiesrepresentsprintingvelocitiesthataresustainableforbriefperiods(≤15s;Brett,1964).Upstreammovementwouldbelimitedatthesevelocitiesandwepredictencounteringthesevelocitieswouldstimulatelarvaetogobackintodrift.

Interandintraspecificcompetitionforhabitatandfoodmayeffectdriftbehavior.Swimupbehaviorwasoftenobservedamonglarvaefromthefirstspawningeventwhentheycontactedlargerindividualsfromthesecondspawningevent(18daydifferenceinage)anddensecongregationsoflarvaewereneverobservedintheartificialriver.Availabilityoffoodappearedtobeastrongdeterminantoflarvalhabitatselection,withlarvaemostlysettlingonthebottominthechannelandbend(C2,B2)belowthepointoffoodentrydespitesimilarhabitat(i.e.similarvelocityandsubstrate)beingavailableintheotherchannelandbend(C1,B1).Relativelyhighdensitiesoflarvaeandcompetitionforfoodandhabitatmayhavecontributedtotheextendeddriftweobservedintheartificialriver.However,extendeddriftbehaviorwasalsoobservedintherelativelylowdensityobservationtanks(Velocity×Temperature;10fish/tank)andintheartificialriverattheendofobservationswhenlessthan50larvaewerepresent(dailysampling,mortality,andremovalforswimstudiesdecreasedfishdensities).Giventheobservedinfluenceoffoodavailabilityonhabitatselection,laboratorystudiesthatusenaturalpreyitems,suchasmidge(Chironomidae)andmayfly(Ephemeroptera)larvae,mayprovidemorerealisticinferencesonhabitatselection(Braatenetal.,2012b;Sechleretal.,2012).

Theabilityoflarvaetosurvivethetransitionfromendogenoustoexogenousfeedingislikelydependentontheavailabilityofsuitablehabitatandsufficientfoodsources.Earlylifestagesareparticularlysensitivetofooddeprivationandmortalityassociatedwithfooddeprivationoflarvalpallidsturgeonrearedat17°Cwasfirstobservedat17dphandwas97%

by23dph(Kappenmanetal.,2011).Weobservedasimilartrendinthe20°CVelocity×Temperaturetanks,indicatinglarvaemayhavediedfromfeedinginefficiently.Shallowwaterandfloodplainhabitatsgenerallysupporthigherdensitiesofzooplanktonandbenthicinvertebratesandwerelikelyhistoricallyimportantnurseryareasforlarvalpallidsturgeon(Thorp,1992;ThorpandDelong,1994;WardandStanford,1995;Scheimeretal.,2001).However,damsandchannelizationhavedisconnectedtheMissouriRiverfromitsfloodplainandresultedinasubstantiallossofshallowwaterhabitat(HesseandSheets,1993;Gallatetal.,1996;Bowenetal.,2003).Thesedecreasesinsuitablehabitatlikelyresultinanextendeddriftphase,delaysinexogenousfeeding,increasedcompetitioninareaswithsuitablehabitat,andultimatelyincreasedmortality.Wilsonetal.(2008)andHaddixetal.(2009a,b)reportincreasedconcentrationsofstockedpallidsturgeondownstreamofstockinglocationsintheUpperMissouriRiver.Thepotentialeffectsofanextendeddownstreamdriftandsubsequentelevatedcompetitionindownstreamstretchesofmanagementareasshouldbeaconsiderationinstockingprotocols.DecreasinggrowthratesamongstockedpallidsturgeonintheLowerMissouriRivermaybeanindicationofelevatedinterspecificcompetitionwiththelargepopulationofshovelnosesturgeonandintraspecificcompetitionwithhatcheryrearedpallidsturgeon(Popeetal.,2010;Steffensenetal.,2018).

Resultsandobservationsfromourstudyindicatethatdownstreamdriftmaycontinueafterexogenousfeedingbeginsifsuitablehabitatisnotavailable.Theextentofdownstreamdriftislikelyhighestinchannelizedsegments,segmentswithlowhabitatdiversity,orareaswithhighlevelsofintraandinterspecificcompetition.Embryonicswimmingbehaviorsallowedembryostoexitsmallretentionareasandenterthemaincurrent,butareunlikelytosignificantlyreduceretentiontimesinlargeretentionareas.Weobservedtheswitchtoexogenousfeedingoccurringinalmosthalfthetimeat20°Cthanat15°C.Dammanagementpracticesthatincreasethetemperatureofreleasedwaterwillsignificantlydecreaselarvaldriftdistancesandlikelyincreaselarvalsurvival.Wedidnotobserveaneffectofvelocityondevelopmentrates.Thus,decreasingflowswilldecreasedriftdistanceduringembryonicdevelopment.However,theeffectsofflowregulationonhabitatavailabilityshouldbecarefullyconsideredashabitatavailabilitymayalsoeffectdriftdistances.

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TABLES

TableI.Averagevelocitiesandstandarddeviations(inparenthesis)ofthethreevelocitytreatmentsintheVelocity×Temperatureexperimentsexaminingtheeffectoftemperatureandvelocityonpallidsturgeonlarvaldevelopment.Positivevelocityisintheclockwisedirection.Bottomvelocitiesweremeasured3cmabovethebottomofthetankandaveragevelocitiesweremeasuredat0.6×waterdepth.

Treatment(cm/s) Bottomvelocity(cm/s) Averagevelocity(cm/s)

0 -4.6(0.5) -0.25(0.7)

10 6.9(1.4) 10.3(1.3)21 17.3(2.4) 20.8(1.9)

TableII.Listofresponsevariablesexaminedineachlarvalpallidsturgeonexperimentandtheirassociatedexplanatoryvariables.

ResponseVariable Experiment ExplanatoryVariables

Presenceoffood Velocity×Temperature Age,length,temperature,velocity

Length(mm) Velocity×Temperature Age,temperature,velocityYolksacarea(mm2) Velocity×Temperature Age,length,temperature,velocity

Ucrit(cm/s) Smallswimchamber;Ucrit Age,lengthUcrit(BL/s) Smallswimchamber;Ucrit Age,lengthUsprint(cm/s) Largeswimchamber;Usprint Age,fincurl,length,tankUsprint(BL/s) Largeswimchamber;Usprint Age,fincurl,length,tank

Metrics:Age(daysposthatch),fincurl(qualitativescaleofpercentageofoutsideedgeofpectoralfinaffected),length(mm;totallength),tank(holding/rearingenvironment),temperature(°C),Ucrit/Usprint(cm/sandbodylengths/s)andvelocity(cm/s).

TableIII.Age(daysposthatch),cumulativethermalunitsfromhatch(CTU,fromhatch),andtotallength(mm)forimportantdevelopmentalfeaturesofpallidsturgeonfreeembryos/larvaeintheVelocity×Temperatureexperiments.Resultsfrom15and20°Ctreatmentspresented;nodifferencesamongvelocitytreatmentswasobserved.Age,CTU,andlengthpresentedasarange(min,max)fromthefirstobservationtowhenthedevelopmentalfeaturewasobservedinallsampledindividuals.

ResponseVariable Age CTU Length(mm)a

15 20 15 20 15 20

Hatchb 0 0 0 0 7.2,8.9 7.6,8.9

Presenceoffoodc 18,23 10,13 275,352 205,268 18.8,18.5 19.6,20.3Absenceofmelaninplug 15,18 8,10 230,275 163,205 18.2,18.5 18.8,19.7

Absenceofyolksac 15,17 9,10 230,260 184,205 17.9,18..5 18.8,19.7Bottomorientation 11d 6,9 168 122,184 16.5 16.7,18.3

a Lengthvaluesrepresenttheaverageofallindividualswiththepresenceofdevelopmentalfeatureonthefirstdaythefeaturewasobservedandthedaywhenthefeaturewasobservedfor“all”larvaeb HatchatlengthispresentedastheminimumandmaximumlengthsobservedforsampledembryoscFoodwasneverobservedforalllarvae.Therangepresentedisthefirstobservationoffoodtothepredictedpeakproportionoflarvaewithfoodpresentinstomachsfromlogisticregression.dNopeakobservedforfishorientedonthebottomforthe15°Ctreatments,onlyvaluesforthefirstobservationofbottomorientationpresented

TableIV.Regressiontableforrelationshipsamonglength,yolksacarea,Ucrit,Usprint,age,temperature(T),velocity,andholdingenvironment(‘tank’)fromlarvalpallidsturgeonVelocity×Temperature,Ucrit,andUsprintexperiments.A“×”isusedtoindicateinteractionsbetweenvariables.

Responsevariable Explanatoryvariable β(±SE) t P-valueProbability ofpresenceoffood

interceptage -5.42(0.45)0.19(0.02)

12.19.8

<0.0001<0.0001

T20 -1.43(0.87) 1.6 0.10

age×temperatureLogisticregression

0.50(0.07) 6.9 <0.0001

Probability ofpresenceoffood

interceptlength -14.60(1.80)0.73(0.10)

8.17.4

<0.0001<0.0001

T20 -14.48(4.00) 3.7 0.0003

length×temperatureLogisticregression

0.83(0.21) 3.9 <0.0001

Length intercept 8.4(0.12) 71.9 <0.0001

age 0.9(0.02) 34.8 <0.0001

T20 -1.2(0.22) 5.5 <0.0001

age×T20 1.0(0.08) 12.8 <0.0001

age2 -0.02(0.001) 14.2 <0.0001

age2×T20 -0.05(0.007) 6.8

F5,607=2727.1;adjustedr2=0.96;P<0.0001

<0.0001

Yolksacarea intercept 7.00(0.08) 82.9 <0.0001 age -0.42(0.01) 52.9 <0.0001

T20 -0.13(0.15) 0.9 0.38

T20×age -0.29(0.02) 12.5F3,508=1288.4;adjustedr2=0.88;P<0.0001

<0.0001

Yolksacarea intercept 13.41(0.25) 54.7 <0.0001

length -0.70(0.02) 43.5 <0.0001

T20 -2.37(0.40) 6 <0.0001

T20×length 0.17(0.03) 6.8F3,508=861.4;adjustedr2=0.84;P<0.0001

<0.0001

ln(Ucrit)-Absolute intercept 2.19(0.07) 32.26 <0.0001

age 0.03(0.003) 8.22F1,115=67.5;adjustedr2=0.36;P<0.0001

<0.0001

ln(Ucrit)-Absolute intercept 2.17(0.06) 34.88 <0.0001

length 0.02(0.002) 9.27F1,115=85.9;adjustedr2=0.42;P<0.0001

<0.0001

Ucrit-Relative intercept 8.02(0.41) 19.59 <0.0001

age -0.09(0.02) 4.96F1,115=24.6;adjustedr2=0.17;P<0.0001

<0.0001

Ucrit-Relative intercept 8.26(0.38) 21.84 <0.0001

length -0.08(0.01) 6.06F1,115=36.7;adjustedr2=0.24;P<0.0001

<0.0001

Usprint-Absolute intercept 14.73(17.33) 0.85 0.4

age 0.34(0.25) 1.36 0.18

fincurl 1.32(0.93) 1.41 0.16

tank 5.34(2.17)F3,71=4.3;adjustedr2=0.12;P=0.008

2.47 0.02

Usprint-Absolute intercept -4.94(5.92) 0.83 0.41

length 0.49(0.06) 8.09 <0.0001

fincurl 0.75(0.66) 1.14 0.26 tank 4.36(1.57) 2.77 0.007 F3,71=28.7;adjustedr2=0.53;P<0.0001

Usprint-Relative intercept 3.55(1.38) 2.6 0.01

age 0.01(0.02) 0.6 0.58 fincurl 0.07(0.07) 1 0.33

2.7 0.01

Usprint-Relative intercept 4.01(0.64) 6.3 <0.0001

length 0.03(0.06) 0.5 0.62 fincurl 0.08(0.07) 1.1 0.29

2.7 0.009

Metrics:Age(daysposthatch),fincurl(qualitativescaleofpercentageofoutsideedgeofpectoralfinaffected),length(mm;totallength),tank(holding/rearingenvironment),temperature(°C),absoluteUcrit/Usprint(cm/s),relativeUcrit(bodylengths/s),velocity(cm/s),andyolksacarea(mm2).T20iscategoricalvariableequalto1for20°Ctreatmentsand0forthe15°

Ctreatmentsandtankisequalto1forfishheldintheartificialriverand0forfishheldinthe1.8mcirculartank.

FIGURES

Figure1.Photographicguideofpallidsturgeonembryonicdevelopment1-7daysposthatch(dph)forembryosrearedat15and20°CfromtheVelocity×Temperatureexperiments.Examplesoftotallengthandyolksacareameasurementsaredenotedbywhitelines.Therewasnoevidenceforarelationshipbetweenvelocityandlengthoryolksacarea.

Note:Localcontrastenhancedinphotographtofacilitateidentificationofdevelopmentalfeatures.

Figure2.Photographicguideofpallidsturgeonembryonicdevelopment9-15daysposthatch(dph)forembryosrearedat15and20°CfromtheVelocity×Temperatureexperiments.Examplesoftotallengthandyolksacareameasurementsaredenotedbywhitelines.Yolksacwasnolongerexternallyvisible15dphand9dphat15and20°C,respectively.Therewasnoevidenceforarelationshipbetweenvelocityandlengthoryolksacarea.

Note:Localcontrastenhancedinphotographtofacilitateidentificationofdevelopmentalfeatures.

15 ° C 20 ° C

11 dph dph

dph 13

dph 15

Figure3:Photographoftheartificialriverusedinobservationalpallidsturgeonlarvaldriftexperiment.

Figure4.Planviewofartificialriveridentifyingimportantstructuresandfeatures.

Figure5:Substratemapoftheartificialriver.

Figure6.LogisticcurvesdescribingtherelationshipbetweentheprobabilityofthepresenceoffoodandageofpallidsturgeonintheVelocity×Temperatureexperimentforthe15(T15)and20°C(T20)treatments.Therewasnoevidenceforarelationshipbetweentheprobabilityofthepresenceoffoodandvelocity

Note:Alllarvaeweredeceasedby21dphinthe20°Ctreatment.

Figure7.Logisticcurvesdescribingtherelationshipbetweentheprobabilityofthepresenceoffoodandlength(mm)ofpallidsturgeonintheVelocity×Temperatureexperimentforthe15(T15)and20°C(T20)treatments.Therewasnoevidenceforarelationshipbetweentheprobabilityofthepresenceoffoodandvelocity.

Figure8.Relationshipbetweenpallidsturgeonlength(mm)anddaysposthatchfortheVelocity×Temperaturetreatments.TemperaturetreatmentsaredenotedT15(15°C)andT20(20°C).Therewasnoevidenceforarelationshipbetweenlengthandvelocity.Regressioncurveswerecalculatedfromareduceddatasetconsistingofdayposthatchbeforethemelaninplugwasshed(18and10dphfor15and20°Ctreatments,respectively).

Figure9.Relationshipbetweenpallidsturgeonyolksacarea(mm2)anddaysposthatchfortheVelocity×Temperaturetreatments.TemperaturetreatmentsaredenotedT15(15°C)andT20(20°C).Therewasnoevidenceforarelationshipbetweenyolksacareaandvelocity.Regressioncurveswerecalculatedfromareduceddatasetconsistingofdayposthatchwhileexternallyvisibleyolksacwasvisible(17and10dphfor15and20°Ctreatments,respectively).

Figure10.Relationshipbetweenpallidsturgeonyolksacarea(mm2)andlength(mm)fortheVelocity×Temperaturetreatments.TemperaturetreatmentsaredenotedT15(15°C)andT20(20°C).Therewasnoevidenceforarelationshipbetweenvelocityandyolksacarea.Regressioncurveswerecalculatedfromareduceddatasetconsistingofdayposthatchwhileexternallyvisibleyolksacwasvisible(17and10dphfor15and20°Ctreatments,respectively).

Figure11.DailymortalityratesinthesixVelocity×Temperatureobservationtanks.Deceasedpallidsturgeonwerereplaceddailyaftermortalitycountstomaintainasamplesizeoften.

Days post hatch Days post hatch

0 5 10 15 20 25 30 0.0 0.2 0.4 0.6 0.8 1.0

5 10 15 20 0.0 0.2 0.4 0.6 0.8 1.0

15 °C × 0 cm/s 20 °C × 0 cm/s

0 5 10 15 20 25 30

0.0 0.2 0.4 0.6 0.8 1.0

5 10 15 20

0.0 0.2 0.4 0.6 0.8 1.0

15 °C × 1 0 cm/s 20 °C × 1 0 cm/s

0 5 10 15 20 25 30

0.0 0.2 0.4 0.6 0.8 1.0

5 10 15 20

0.0 0.2 0.4 0.6 0.8 1.0

15 °C × 21 cm/s 20 °C × 21 cm/s

Figure12.Contourvelocitymapoftheartificialriver.Eachvelocitymeasurement(n=6588)represent30sfixedpointaveragestaken3cmabovethesubstrate.

Figure13.RelationshipbetweenabsoluteUcrit(cm/s;n=117)andA)age(daysposthatch;R2=.36)andB)length(cm;R2=0.42)forlarvalpallidsturgeon.

Figure14.RelationshipbetweenrelativeUcrit(Bodylengths/s;n=117)andA)age(daysposthatch;R2=0.17)andB)length(cm;R2=0.24)forlarvalpallidsturgeon.

Figure 15. Relationship between absolute Usprint (cm/s; n=75) and fish length (TL, cm; R2=0.53) for fish held in a 1.8 m circular tank and 20 m (circumference) oval artificial river.

GeneticIdentificationofLarvalSturgeonfrom2016UpperMissouriRiverLarvalDriftStudy

FinalReportDecember12,2017

MontanaFish,Wildlife&Parks Contract:FWP#17-599

Submittedto:

StateofMontana Fish,Wildlife&Parks

1AirportRd. Glasgow,MT

EdHeist,RachelGockerandAmyBuhman SouthernIllinoisUniversityCarbondale

CenterforFisheries,Aquaculture&AquaticSciences LifeSciencesIIRoom251

1125LincolnDrive Carbondale,IL62901

Introduction,MaterialsandMethods PatBraatenoftheU.S.GeologicalSurvey,FortPeckoffice,provided1269acipenseridfreeembryosand411youngoftheyear(YOY)larvaeaspartofthe2016upperMissouriRiverlarvaldriftstudy.FreeembryosandYOYweregeneticallyidentifiedfollowingtheprotocolsofEichelbergeretal.(2014)withsomemodifications.TissuesampleswerefirstdigestedusingAppliedBiosystemsSample-to-SNPkit.Becausepaddlefishandsturgeonfreeembryosaremorphologicallyindistinguishable,freeembryoswerefirstgenotypedatamitochondrialSingleNucleotidePolymorphism(SNP)thatdistinguishesbetweenpaddlefishandsturgeon(Heist,unpublished).Freeembryospossessingthenucleotide“A”attheSNPwereidentifiedassturgeon,whilethosewithnucleotide“G”wereidentifiedaspaddlefish.FreeembryosthatwereidentifiedassturgeonandsturgeonYOYwereanalyzedatoneortwonuclearSNPlociforwhichnearlyallpallidsturgeonarehomozygousforanallelethatisrareinshovelnosesturgeon.Atleast95%ofpallidsturgeonfromtheMissouriRiverpossessgenotype“GG”forSNPlocusRAG-1Aandgenotype“AA”forSNPlocusIGF-2B.Onlyabout2%ofshovelnosesturgeonpossessbothofthesegenotypes.WefirstscreenedforlocusRAG-1Aandifthelarvaorfreeembryohadgenotype“GG”we

thenscreenedforlocusIGF-2B.Anylarvaorfreeembryothathadgenotype“GG”forlocusRAG-1ASNPlocusandgenotype“AA”forSNPlocusIGF-2Bwasconsidereda“potentialpallid”andwasidentifiedtospeciesusingDNAmicrosatellites.Freeembryosandlarvaeidentifiedas“potentialpallids”weregenotypedat19DNAmicrosatellitelocifollowingtheprotocolsofSchreyetal.(2011).Todeterminewhethereachspecimenwasapurepallidsturgeon,pureshovelnosesturgeon,orahybridweusedtheNewHybridssoftwarepackageofAndersonandThompson(2002)usinglocalbaselineallelefrequenciesforpallidandshovelnosesturgeon.Thebaselinesturgeonwerepreviouslyidentifiedusingacombinationofmolecularanalysisandmorphologicaldataandincludes175pallidsturgeonand128shovelnosesturgeonfromtheGreatPlainsManagementUnit.Afishwasidentifiedasapurepallidsturgeonifit’sprobabilityofassignmenttothepurepallidsturgeoncategorywas≥0.95.WeusedtheCervussoftwarepackageofKalinowskietal.(2007)toidentifytheparentageofpallidsturgeonfreeembryosandYOYbasedontheparentalgenotypesandknowncrossesamongthe7femaleand9malepallidsturgeonbroodstockusedtoproducethefreeembryosforthedriftstudy.

ResultsSNPanalysesidentified74freeembryosas“potentialpallids,”559asshovelnosesturgeon,634aspaddlefish,and2freeembryosfailedtoproducesufficientDNAforreliableanalyses(Appendix1).58ofthepotentialpallidswereamongthe90freeembryosfrombox1withtheremaining14distributedamongthe1179freeembryosintheremaining14boxes.AnalysisofmicrosatellitedatausingNewHybridsrevealedthatall58“potentialpallids”frombox1werepallidsturgeonwhiletheremaining14wereshovelnosesturgeon(Table1).Parentageanalysisidentifiedallpallidsturgeonfreeembryosasoffspringofthe7femaleand9malebroodstockparents.Therewasstrongcorrespondencebetweenthenumberofembryosstockedperfamilyandthenumberrecovered(datanotshown),althoughtwoofthefreeembryosmatchedcrossesbetweenparentsusedtoproducethefreeembryosbutincrossesthatwerenotdocumented(Table2).SNPanalysesidentified7ofthe452YOYas“potentialpallids,”443asshovelnosesturgeon,and2samplesfailedtoproducesufficientDNAforreliableanalyses(Appendix2).All9ofthe“potentialpallid”YOYwereidentifiedasshovelnosesturgeon(Table3).

LiteratureCitedAndersonEC,ThompsonEA(2002)Amodel-basedmethodforidentifyingspecieshybridsusing

multilocusgeneticdataGenetics,160,1217-1229.EichelbergerJS,BraatenPJ,FullerDB,KrampeMS,HeistEJ(2014)NovelSingle-Nucleotide

PolymorphismMarkersConfirmSuccessfulSpawningofEndangeredPallidSturgeonintheUpperMissouriRiverBasin.TransAmFishSoc,143,1373-1385.

KalinowskiST,TaperML,MarshallTC(2007)RevisinghowthecomputerprogramCERVUS

accommodatesgenotypingerrorincreasessuccessinpaternityassignment.MolEcol,16,10991106.

SchreyAW,BoleyR,HeistEJ(2011)HybridizationbetweenpallidsturgeonScaphirhynchusalbusand

shovelnosesturgeonScaphirhynchusplatorynchus.JFishBiol,79,1828-1850.

Table1.NewHybridsanalysisof72“potentialpallids.”Dataincludeboxnumber,IndividualID,Newhybridprobabilitiesthatafreeembryoisapurepallidsturgeon(Pal),hybrid(Hyb),orshovelnose(Sho)sturgeonandspeciesID.Box ID Pal Hyb Sho Species

1 0091 1.000 0.000 0.000 Pallid

1 0104 1.000 0.000 0.000 Pallid

1 0105 1.000 0.000 0.000 Pallid

1 0652 1.000 0.000 0.000 Pallid

1 0668 1.000 0.000 0.000 Pallid

1 0794 1.000 0.000 0.000 Pallid

1 0795 1.000 0.000 0.000 Pallid

1 1849 1.000 0.000 0.000 Pallid

1 0092-A 1.000 0.000 0.000 Pallid

1 0092-B 1.000 0.000 0.000 Pallid

1 0095-A 1.000 0.000 0.000 Pallid

1 0095-B 1.000 0.000 0.000 Pallid

1 0096-A 1.000 0.000 0.000 Pallid

1 0096-B 1.000 0.000 0.000 Pallid

1 0096-C 1.000 0.000 0.000 Pallid

1 0097-A 1.000 0.000 0.000 Pallid

1 0097-B 1.000 0.000 0.000 Pallid

1 0098-A 1.000 0.000 0.000 Pallid

1 0098-B 1.000 0.000 0.000 Pallid

1 0098-C 1.000 0.000 0.000 Pallid

1 0101-A 1.000 0.000 0.000 Pallid

1 0101-B 1.000 0.000 0.000 Pallid

1 0102-A 1.000 0.000 0.000 Pallid

1 0102-B 1.000 0.000 0.000 Pallid

1 0102-C 1.000 0.000 0.000 Pallid

1 0103-A 1.000 0.000 0.000 Pallid

1 0103-B 1.000 0.000 0.000 Pallid

1 0103-C 1.000 0.000 0.000 Pallid

1 0777-A 1.000 0.000 0.000 Pallid

1 0777-B 1.000 0.000 0.000 Pallid

1 0777-C 1.000 0.000 0.000 Pallid

1 0777-D 1.000 0.000 0.000 Pallid

1 0777-E 1.000 0.000 0.000 Pallid

1 0777-F 1.000 0.000 0.000 Pallid

1 0777-H 1.000 0.000 0.000 Pallid

1 0777-I 1.000 0.000 0.000 Pallid1 0777-J 1.000 0.000 0.000 Pallid1 0784-A 1.000 0.000 0.000 Pallid1 0784-B 1.000 0.000 0.000 Pallid1 0784-C 1.000 0.000 0.000 Pallid1 0784-D 1.000 0.000 0.000 Pallid1 0784-E 1.000 0.000 0.000 Pallid1 0784-F 1.000 0.000 0.000 Pallid1 0784-G 1.000 0.000 0.000 Pallid1 0784-H 1.000 0.000 0.000 Pallid1 0785-A 1.000 0.000 0.000 Pallid1 0785-B 1.000 0.000 0.000 Pallid1 0785-C 1.000 0.000 0.000 Pallid1 0785-D 1.000 0.000 0.000 Pallid1 0785-E 1.000 0.000 0.000 Pallid1 0785-F 1.000 0.000 0.000 Pallid1 0785-G 1.000 0.000 0.000 Pallid1 1847-A 1.000 0.000 0.000 Pallid1 1847-B 1.000 0.000 0.000 Pallid1 1847-C 1.000 0.000 0.000 Pallid1 1848-A 1.000 0.000 0.000 Pallid

1 1848-B 1.000 0.000 0.000 Pallid1 1848-C 1.000 0.000 0.000 Pallid3 1171 0.000 0.018 0.982 Shovelnose5 1834 0.000 0.001 0.999 Shovelnose5 1837 0.000 0.001 0.999 Shovelnose5 2037 0.000 0.188 0.812 Shovelnose6 0077-B 0.000 0.000 1.000 Shovelnose6 0078-D 0.000 0.001 0.999 Shovelnose8 2098 0.000 0.021 0.979 Shovelnose8 0390-J 0.000 0.001 0.999 Shovelnose9 0676-B 0.000 0.002 0.998 Shovelnose11 2214 0.000 0.002 0.998 Shovelnose12 1530 0.000 0.001 0.999 Shovelnose12 2253-A 0.000 0.000 1.000 Shovelnose15 0360-A 0.000 0.000 1.000 Shovelnose15 0429-A 0.000 0.002 0.998 ShovelnoseTable2.ParentageofpallidsturgeonfreeembryosincludingsampleIDandPITtagsoffemaleandmaleparents.Twofishmarkedwithasteriskappeartobeoffspringofparentsusedforthestudybutfromacrossthatwasnotdocumented.ID Female Male

0105 115557165A 132313521A

0652 115557165A 132313521A

1849 115557165A 132313521A

0095-B 115557165A 132313521A

0096-B 115557165A 132313521A

0103-B 115557165A 132313521A

0777-D 115557165A 132313521A

0777-J 115557165A 132313521A

0784-B 115557165A 132313521A

0785-B 115557165A 132313521A

0785-C 115557165A 132313521A

1847-B 115557165A 132313521A

1847-C 115557165A 132313521A

1848-B 115557165A 132313521A

1848-C 115557165A 132313521A

0668 115557165A 411D0B4E09

0777-I 115557165A 411D0B4E09

0785-A 115557165A 411D0B4E09

1847-A 115557165A 411D0B4E09

0104 1F497F1801 0A180E0E7E

0092-A 1F497F1801 0A180E0E7E

0102-A 1F497F1801 0A180E0E7E

0102-C 1F497F1801 7F7D7C2447

0103-C 470378405D 132313521A *

0097-B 470378405D 220F107A6F

0098-B 470378405D 220F107A6F

0101-B 470378405D 220F107A6F

0777-A 470378405D 220F107A6F

0777-B 470378405D 220F107A6F

0777-C 470378405D 220F107A6F

0784-D 470378405D 220F107A6F

0784-F 470378405D 220F107A6F

0096-A 470378405D 411D0B4E09

0102-B 470378405D 411D0B4E09

0103-A 470A675627 7F7D7C2447 *

0091 470A675627 7F7F065834

0794 470A675627 7F7F065834

0795 470A675627 7F7F065834

0092-B 470A675627 7F7F065834

0095-A 470A675627 7F7F065834

0096-C 470A675627 7F7F065834

0097-A 470A675627 7F7F065834

0098-A 470A675627 7F7F065834

0098-C 470A675627 7F7F065834

0101-A 470A675627 7F7F065834

0777-F 470A675627 7F7F065834

0784-A 470A675627 7F7F065834

0784-C 470A675627 7F7F065834

0784-G 470A675627 7F7F065834

0784-H 470A675627 7F7F065834

0785-D 470A675627 7F7F065834

0785-E 470A675627 7F7F065834

0785-F 470A675627 7F7F065834

0785-G 470A675627 7F7F065834

0777-E 7F7FD66963 132313521A

0777-H 7F7FD66963 132313521A

0784-E 7F7FD66963 132313521A

1848-A 7F7FD66963 132313521A

Table3.NewHybridsanalysisof9“potentialpallid”YOY.Dataincludeboxnumber,IndividualID,Newhybridprobabilitiesthatafreeembryoisapurepallidsturgeon(Pal),hybrid(Hyb),orshovelnose(Sho)sturgeonandspeciesID.Sample Pal Hyb Sho Species0967 0.000 0.002 0.998 Shovelnose1068 0.000 0.002 0.998 Shovelnose1085 0.000 0.001 0.999 Shovelnose

1341 0.000 0.001 0.999 Shovelnose1596 0.000 0.001 0.999 Shovelnose2308 0.000 0.013 0.987 ShovelnoseSTURG-4800A 0.000 0.001 0.999 ShovelnoseNOTE:TheappendicestothisreporthavebeendeletedtolimitthelengthoftheAnnualReport.Acopyofthecompletereportcanbemadeavailableonrequest.9BobSnyder,UpperBasinWorkgroupFacilitator)

OtherSIUCUpperBasinProjects

Dr.Heist’slabatSouthernIllinoisUniversityCarbondaleidentified1267acipenseriformfreeembryosand450sturgeonyoungoftheyear(YOY)aspartofthe2016upperMissouriRiverdriftstudy.Ofthe1267freeembryos,543wereidentifiedasshovelnosesturgeon,634aspaddlefish,and58aspallidsturgeon.Allofthepallidsturgeonwereoffspringofbroodstockparentsusedtoproduceembryosforthedriftstudy.AlloftheYOYwereidentifiedasshovelnosesturgeon.

Dr.HeistalsobeganaWAPA-fundedstudytoidentifytheoptimumprotocolandtheearliestlifestagesatwhichsturgeonfreeembryoscouldbegeneticallyidentified.Wetested4commercialkitandidentifiedonewhichproducedthehighestyieldandDNAconcentration.Usingthatkit,hatcheryproducedfreeembryosatstage5failedtoproducesufficientnuclearDNAforamplificationofmicrosatellites,stages7-9producedsomeamplificationbutmanylocifailedandsomecallsappearedquestionable.Stage14freeembryosproducedsufficientDNAforamplifyingallloci.Wearecurrentlyusingparentageanalysistodeterminewhetherthedataproducedfromthestage14freeembryoswerereliableandarealsousingthechosenkittoisolateandamplifyDNAfromstagedwild-caughtfreeembryos.

DeterminationofReproductiveIndicesinHatchery-originPallidSturgeonintheMissouriandYellowstoneRivers

2017-2018AnnualReport

MollyA.H.Webb

USFWS,BozemanFishTechnologyCenterExecutive Summary: This project will determine the age at sexual differentiation, onset ofpubertyand firstmaturity,andspawningperiodicityofhatchery-origin (HO)pallid sturgeon inthe Missouri and Yellowstone rivers using known-aged juvenile pallid sturgeon. Millions ofdollarsandconsiderableeffortforendangeredpallidsturgeonintheupperbasinoftheMissouriRiver has beenplaced in the conservationpropagationprogram to prevent extirpationof thespecies. Hundredsof thousandsofpallidsturgeonyoung-of-yearhavebeenreleased into theupperMissouriRiversince1998.Thosefisharenowreachingsexualmaturityasdeterminedbycirculatingsexsteroidconcentrations.Astheheritagefishageanddie,wewillbereliantontheHOpallidsturgeontomaintainthespecies.UnderstandingwhethertheHOpallidsturgeonarecapableofreestablishmentthroughnaturalspawningisvitaltotherecoveryprogram.Since 2009, 986 plasma samples from HO pallid sturgeon captured in the Missouri andYellowstonerivershavebeenanalyzedtodetermineage-at-maturity.The1997andolderyearclasses provide an opportunity to determine age and size at onset of puberty and spawningperiodicityinpallidsturgeonasthesefisharenowover20yearsold.Sex steroids can be used to determine sex and stage of maturity less invasively in sturgeonspeciescomparedtoothertechniquessuchasbiopsy(WebbandDoroshov,2011;Webbetal.2018).TheobjectiveofthisprojectistoanalyzebloodplasmasexsteroidconcentrationsinHOpallidsturgeonintheupperMissouriandYellowstoneriverstoassignsexandstageofmaturityanddeterminetheageandsizeatsexualdifferentiationandfirstmaturityaswellasspawningperiodicity.Project Status/Anticipated/Expected Date of Completion: This project was completed inMarch2018.Analysisof986pallidsturgeonplasmasamplesisreportedhere.Accomplishments/Recommendations/Results:MethodsBloodplasmasamplesfromHOpallidsturgeonthathavebeenanalyzedtodatefortestosterone(T)andestradiol(E2)concentrationswerecollectedfrom:RPMA1byMontanaFishWildlifeandParks (MTFWP) personnel in the Spring and Fall of 2011, 2012, 2013, 2014, 2015, 2016, and2017;RPMA2ontheMissouriRiverbyUSFWSpersonnel inSpringof2010,2011,2015,2016,2017andFall2011,2012,2014,2015,2016,and2017;RPMA2ontheMissouriRiverbyMTFWPinSpringandFallof2012,2014,2015,2016,and2017;RPMA2ontheYellowstonebyMTFWPinSpring2014,2015,2016,2017andFall2011,2013,2014,2015,2016,and2017;RPMA3byUSFWSpersonnelinSpring2012,2013,2014,and2016.CapturelocationontheMissouriRivervaried between river mile (RM) 1880 and 2050 for RPMA 1, between RM 1533 and 1762 inRPMA2,andbetweenRM828and831inRPMA3.CapturelocationontheYellowstoneRivervaried between RM 8 and 70. Blood samples were collected from the caudal vasculature,centrifugedtoseparateplasma,frozen,andsenttotheBozemanFishTechnologyCenter(BFTC)

for analysis of plasma T and E2 concentrations. Blood plasma steroid concentrations weremeasuredbyradioimmunoassayfollowingthemethodsdescribedinFitzpatricketal.(1986)andmodifiedbyFeistetal.(1990).ResultsandDiscussionBloodplasmaT and E2 concentrations havebeen analyzed in a total of 986 samples to date.Theyoungestyearclasstobesampledwas2011(age2attimeofcapture)andtheoldestwas1997 (age 20 at time of capture). In the 2017 dataset, five reproductive HO males wereidentified.Thesefivemaleswerefromthe1997,2002,and2006yearclasses.Ofthefivemales,twowerecapturedinRPMA1,andthreewerecapturedinRPMA2.Fishageswere20forthe1997yearclass,15forthe2002yearclass,and11forthe2006yearclass.Bodysizerangedfrom950-1215 cm fork length and 5.3-8.7 kg body weight. Four HO reproductive females wereidentifiedin2017.Twofemaleswereripeinthespring,andtwofemaleswerecapturedinthefallandshouldberipein2018.Threefemaleswerefromthe1997yearclass,andonefemalewasfromthe2004yearclass(13yearsoldatcapture;tobe14yearsoldinthe2018spawningseason).The2004yearclassfemalewascapturedinthefall.Bodysizewas1170and1185cmforklengthand7.6and8.3kgbodyweightforthetwofemalescapturedinthespring.Bodysizewas1075and1078cmforklengthand5.6and5.9kgbodyweightforthetwofemalescapturedinthefall.In2017,FemaleF136Dfromthe2004yearclasswascapturedbyMatRuggandhiscrewinthefall and assigned as a ripe female using plasma sex steroids. It would be very beneficial torecapturethisfemaleandcollectbothbloodplasmaandovarianfolliclesinthe2018spawningseason. Shewould be the youngest pallid sturgeon to spawn in our dataset at an age of 14years.TheyoungestHOmaletoshowsignsofreproductivematurityhasbeendocumentedattheageof10asseenbyplasmaTconcentrationsabove38ng/ml.AllothermatureHOmaleshavebeen14yearsorolder.RecaptureofCode83,91,and100inthespringof2018willprovidevaluablespawningperiodicityinformation.Since2011,usingbothdatafromHolmquistetal.(InReview)andthisstudy,wehavebeenableto determine the spawning periodicity in 8 HO males. Six males have had an annualreproductive cycle, and twomales have had binennial cycles.More information needs to becollectedovertimetodeterminespawningperiodicityinfemales.Dummyruns,inwhichfishproduceovarianfolliclesbutdonotovulateandovipositduringtheirfirst cycle, have been described in other long lived species such as rockfish and cod. Massfollicularatresiaistheresult.Thedummyrunmay'condition'gonadsandotherorgansthroughthe elevation of circulating hormones, which would, upon subsequent hormone exposure,decrease the cellular response time, rate of target receptor upregulation and binding proteinsynthesis. This process is similar to the immune response, where physiological “learning”primesthesystemforasubsequentresponsefollowingfirstexposuretothephysiologicalevent.All of the HO ripe females followed in this study to date have undergone follicular atresiaindicating a potential of a dummy run in pallid sturgeon females. There is great value infollowingthereproductivefateofthosefemalesinsubsequentcyclestodetermineiffollicularatresia may be attributed to a dummy run or lack of environmental conditions suitable forspawning.

ReferencesFeist,G.,C.B.Schreck,M.S.Fitzpatrick&J.M.Redding.1990.Sexsteroidprofilesofcohosalmon(Oncorhynchus kisutch) during early development and sexual differentiation. General andComparativeEndocrinology80:299-313.Feist, G., J.P. Van Eenennaam, S.I. Doroshov, C.B. Schreck, R.P. Schneider, &M.S. Fitzpatrick.2004. Early identification of sex in cultured white sturgeon, Acipenser transmontanus, usingplasmasteroidlevels.Aquaculture232:581-590.Fitzpatrick,M.S., G. Van Der Kraak & C.B. Schreck. 1986. Profiles of plasma sex steroids andgonadotropin in coho salmon,Oncorhynchus kisutch, during final ovarianmaturation.GeneralandComparativeEndocrinology62:437-451.Holmquist, L.M., C.S. Guy, A. Tews,&M.A.H.Webb. In Review. Firstmaturity and spawningperiodicity of hatchery-origin pallid sturgeon in the upper Missouri River above Fort PeckReservoir,Montana.JournalofAppliedIchthyology.Webb,M.A.H.& S.I. Doroshov. 2011. Importance of environmental endocrinology in fisheriesmanagementandaquacultureof sturgeons.GeneralandComparativeEndocrinology170:313-321.Webb,M.A.H,VanEenennaam,J.P.,Crossman,J.A.,&Chapman,F.A.2018.Apracticalguideforassigningsexandstageofmaturityinsturgeonsandpaddlefish.JournalofAppliedIchthyology,00,1-18.https://doi.org/10.1111/jai.13582

2017PallidSturgeonPropagationActivitiesforGavinsPointNFH

Introduction

In1993ThePallidSturgeonRecoveryPlanprovideddirectionforpropagation,researchneeds,collectionofwildfishandreintroductionofpallidsturgeontoaugmentrecoveryefforts.Productionofwildandcaptiveheldpallidsturgeonwassuccessfulin2017producing502,829eggsfrom11captivefemalesand8wildbroodfish.Atotalof47wildadultsofmiddlebasinoriginweretransferredtoGavinsPointNFHfromSeptember2016toApril2017,withthehelpofmultipleagencies.

CaptiveBroodStockProduction

GavinsPointNFHiscurrentlyrearing1,904captivepallidsturgeonbroodfishthatrepresent20yearclassesasabackupgeneticpoolforuseinsupplementingwildpopulationsandresearchneeds.These1904progenyheldinrefugerepresent146wildindividualsfromupperbasinspawns.These146individualsrepresent154uniquefamilycrosses.

CaptiveBroodStockSpawning

In2017therewerethreespawningeventsinvolving11femalesand8males.Fourdifferentstudieswereconductedusingtheeggsfromthesefish.ThefirststudywasconductedbyUSGS-Yanktonwherenewlyhatchedembryoswereplacedintomesocosmstolookatearlylifestagebehavior,specificallylarvaldrift.Thesecondspawningconsistedof6femalesand4males.Theeggsproducedfromthisroundofspawningwereusedfortwostudies.ThefirstwasagenomicsstudywhereresearchersfromUSGSandSouthernIllinoisweretryingtosequencepallidsturgeonDNA.Thisisdonebyusinguvtreatedpaddlefishmilttofertilizeviablepallideggs,thusmakingatruehaploidoffspringwithonlythemothersDNA.Thesecondstudywasanearlylifestagestudyconductedbyre-searchersatBozemanFishTechnologyCenter(BFTC).Thelastspawningeventutilized4femalesand3males.TheeggsproducedfromthisstudyweretransferredtoBFTCtoagainbeusedinanearlylifestagestudy.Some60,000eggswerekeptandhatchedandondayposthatchtransferredtoSouthDakotaStateUniversitytobeusedforlarvaldriftstudies.

MiddleBasinSpawning

SeveralspawningeventsoccurredatGavinsPointNationalFishHatcheryin2017.OnApril19thafemale(47163E0030)thatwasheldinhatcheryfortwoyears,waspairedwithtwocryo-preservedmales(4626513A54and4627144425).Theyproduced42,750fertilizedeggsat38eggs/ml.Additionally,efforttook41hourstoovulateandtemperaturesrangedfrom55to58°F.

ThesecondspawningeventtookplaceduringApril26th-28thandresultedinsuccessfulspawnof8familylots.Fourfemalesproducedeggs4627463568(28,000),46280F5C1C(33,440),4627545945(27,675)and46274F3A60(20,425)andeightmaleswereused.Female4627463568and46274F3A60werecapturedinthespringof2017.Female46280F5C1Cand4627545945werebothholdoverpallidsturgeonfrompreviousyears.ThePallidSturgeonPITtagged(46280F5C1C)isaspecialcase;in2015itspawnedandproduced5mlofspermwhile5%active

butwasnotviableenoughforcryo-preservation.Thisfishwasheld-overatthehatcherytomonitoritsprogression.Thenin2016,thefishhadwhiteeggspresentafteranultrasoundwasconducted,thenlaterithaddevelopedandproducedblackeggsin2017.

AthirdspawningeventtookplaceonMay4thwithtwofemalesandfourcryo-preservedmalesBothfemalesproducedfertilizedeggs.Female47160E450Bwascapturedinthefallof2016andproduced26,865eggs.Female462764734Fwascaughtinthespringof2017andproduced6,570eggsin2017.

AfourthspawningeventtookplaceonJune6thwithonefemaleandtwocryo-preservedmales.Female46271E7B23wascapturedinthespringof2017andproduced19930viableeggsthuscreatingtwofamilygroups.

Anothernote,fourfemales(4627463568,46274F3A60,462764734F,46271E7B23)thatallsuccessfullyspawnedwereobservedtohavethespeciesPolypodiumhydriforme;aparasiteknownforattackingfisheggsinsturgeonandpaddlefishspecies.

Inadditiontoeightfemalesbeingsuccessfullyspawned11ofthe12malesthatwerespawnedwerealsocryo-preserved.Themaleindividualswhowerenotcryo-preservedwaskeptatthefacilityandwillbespawnedinafutureyearandenteredintothecryo-repository.

Sixoftheeightfemale’soffspringexperiencedearlylifestagemortalityandthereforethesesixfemaleswillbeheldatthehatcheryandspawnedagainwhenviableeggsareproduced.InJanuaryof2017allwildfishwereassessedforspawningreadinessviaultrasound,whichresultedin3reproductivefemalesand10reproductivemales.Duringthespringcaptureanadditional5reproductivefemalesand2reproductivemaleswerebroughttothehatchery.

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