bluefin tuna and swordfish science projects in 2016/2017gnsta.com/alpac2016.pdf · curved fork...

Bluefin Tuna and SwordfishScience Projects in 2016/2017

Presented by Alex Hanke

http://www.invernesssouth.com/uploads/1/8/2/9/18294681/bluefin_tuna_and_swordfish_science_projects_in_2016.pptx 2017-04-17, 10E36 AM of 35

OVERVIEW

Biological Sampling Program OverviewResearch in 2016

Supporters in 2016

• NSLA and Hi-Liner for contribution of headsand transportation (Troy Atkinson).


Loading…• PEIFA (Laura Ramsay), PEI Fisheries Dept.

(Dave MacEwen and crew) and FrancisMorrissey.

• Northwest Atlantic Fisheries Centre forsampling (Mark Simpson and crew).

• SWNSFA and Canso (Eric Jacquard, SteveMead, Frank, Robert Conrad, BrandonDoucette)

• Anna MacDonnell and Warren Joyce at BIO

How Sampling Helps Science


Otoliths• Direct ages for age-

length key and growth• Stock origin/mixing

using isotopes• Stock origin using

shape and genetics• Stock specific age-

length key

Head steaks• Any kind of

genetic work,i.e. stock origin

• Diet analysis• Lipid analysis

Spine• Validate spine ages

using otoliths• Direct ages for

age-length keybased on spines

• Source of DNA forstock origin

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Curved ForkLengthRound WeightTag #

2016 Sampling Results

Location Otoliths Head Steaks Spines Total

Nova Scotia

Arisaig 2 2 1 3

Ballentynes Cove 0 0 1 1

Canso 80 94 26 104

SWNS/LL 48 110 18 148

Halifax 2 2 0 2

Wedgeport 15 12 13 15

147 220 59 273

PEI

Alberton 4 4 0 4

Tignish 88 24 0 88

Sea Cow Pond 15 7 1 15

Morell 19 15 0 19

North Lake 61 29 0 64

187 79 1 190


Newfoundland 6 13 0 13

Comparison across Years:Otolith/Head

Location 2010 2011 2012 2013 2014 2015 2016

Nova Scotia

Canso 0/0 52/52 33/33 11/11 38/42 52/52 80/104

SWNS/LL 65/65 59/59 58/59 42/53 51/108 60/197 48/148

Port Hood 0/0 0/0 45/45 121/121 0/0 11/28 0/0

Wedgeport 7/7 8/8 15/15 9/12 13/16 11/11 15/15

72/72 119/119 151/152 183/197 102/166 134/288 147/273

PEI

Tignish 0/0 57/57 74/74 65/77 51/61 66/68 88/88

North Lake 1/1 78/78 63/63 65/73 114/140 100/109 61/64

1/1 135/135 137/137 130/150 161/190 166/177 187/190

Newfoundland

8/8 0/0 0/0 25/35 22/31 5/5 6/13

TOTAL 81/81 254/254 289/289 338/382 289/393 305/470 340/476


RESULTS FROM THESAMPLING

Direct BFT ages• New growth curve estimated using

direct ages and tagging data


Slicing, Pooled ALK or Hybrid


VPA results between the three methods of obtainingcharacterizing catch data for WBFT. The red line indicates theyear (2010) when the most ageing data enters in the models forthe hybrid method.

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Mixing

Eastern fishare smallerand younger. Most recentyear classesare source ofmost easternfish. Eastern fish

Otolith microchemistry based assignment results


in Nfld areolder thanelsewhere.

DNA based assignment results

30e 70w

70e 30w

50e 50w

0e 100w


100e 0w

Weight Distribution ofLanded CatchGulf and SWNS BFTcatch composition basedon round weights of fish.The two fisheries weredistinctly different butnow have very similarcatch compositions. Young western fishmoving into Gulf and/oreastern fish entering Gulf.

175

350


Direct Age from Spines and Otoliths

Canadian samples are essential toincrease number of ageinterpretations from old fish

Agreementbetween spineage and otolithage forsamples fromthe east andCanada. EnriqueRodriguez-Marin

Spine RemovalFor a spine to be valuable for ageing,the condyle (knobby bit ) should be


present.

Otolith Shape AnalysisOtolith shape variation provides amarker of stock origin for northAtlantic bluefin tuna (Thunnusthynnus)Dr. Dierdre Brophy, Galway-MayoInstitute of Technology, and others

• Otolith shape changes with length• Otolith shape differs between

stocks


• ~83% accuracy separating Easternfrom Western fish for fish over 200cm

• Stock assignment based on shapewill not be used in the assessment.

Diet and Lipid AnalysisDr. Walter Golet, University ofMaine/Gulf of Maine ResearchInstitute, Hugues Benoit, GulfResearch Centre, Michael Stokesbury,U de Acadia, Jose Luis Varela, U. deCadiz

• Stomachs, liver, head steaks• Total calories and lipid content of

the tissue• Quality of foraging conditions and

fattening rates• Relates to market value• Impacts fecundity (egg number,


quality and larval growth and survival)Tissues from 2015 have beenprocessed. Analysis postponeddue to loss of analyst.

Bluefin eat squid and hagfish

OTHER PROJECTS


Combined indexAlex Hanke

• Allows us to tune assessmentmodel using a single catch ratetime series rather than usingseveral with conflicting signals

• Indices affected by redistribution ofstock components

• Combine areas and create a singleindex for 6 to 26 year olds

Other ideas:

• Merge US and Canadian RR data• Merge US and Canadian LL data• Merge US, Japanese and Canadian

LL data

Joint Canada RRindex

SWNS

Acoustic

Combined

GSL


Length Based Indicators• Use size samples of

the landed catch• Indicates if the

population is beingsustainably oroptimally harvested

Fraction mega spawners

Fraction mature

Fraction at Lopt

BFT Movement fromCombined PSAT tag data Deployment length and timing


• GBYP requested CPCs to providetheir PSAT tag data in anaggregated format to helpcondition the operating model usedfor MSE

• Most of he 722 deployments areshorter than a year.

• Some concerns regarding longevityof tags

• Not good if you want to resolve arepeated annual cycle or somethingmore complex.

• ~ 300 additional tags have been

provided by B.B.

WEST

EAST

Movement Matrix• The passage probabilities are the probability that each area will

be visited within a specified length of time (365 days).

• Low probability that fish reach East from West.• Fairly high probability of reaching WATL and GSL.


• How sensitive are the outcomes to the bias in the data, lack ofstock origin and short deployments?

Passage probabilities

From\To W_ATL MED SE_ATL NE_ATL C_ATL CAR GSL GOM

MED 0.17 0.96 0.61 0.3 0.1 0.17 0.02

SE_ATL 0.24 0.8 0.73 0.41 0.15 0.24 0.03

NE_ATL 0.32 0.56 0.75 0.53 0.22 0.32 0.04

C_ATL 0.67 0.33 0.43 0.41 0.56 0.67 0.13

CAR 1 0.04 0.06 0.06 0.19 1 0.29

GSL 1 0.04 0.07 0.06 0.19 0.9 0.21

GOM 1 0.04 0.06 0.06 0.18 1 1

W_ATL 0.04 0.07 0.06 0.19 0.9 1 0.22

Improving Bluefin Tuna CatchRate Indices for SouthwesternNova Scotia (SWNS) and the


Southern Gulf of St. Lawrence(sGSL)

Anne CheverieDFO Aquatic Science Biologist

Fishermen-identified Issues withPrevious Indices

SWNS index• Total hours fished may not be reliable• By-catch effort may be included• Does not adjust for concurrent trips• Includes tournament trips sGSL index• Total hours fished may not be reliable


• May be influenced by changes in managementmeasures and fishing patterns

Progress in 2016/2017

• Creation, validation and QA/QC of new SWNSdataset (2002-2015)

• Creation and validation of new sSGL dataset(2003-2015)

• Initial attempts to recalculate fishing effort• Development of new Bluefin tuna logbook


New SWNS Dataset (2002-2015)

• Includes large pelagics trips, including all tripswhere Bluefin tuna were or had the potential tobe caught

• Resolves duplication of Bluefin tuna in2002/2003

• Provides detailed set-level information• Includes all by-catch species• Includes data from other logbooks for

concurrent fishing trips• Enables easy identification of multi-hail trips

QA/QC of SWNS Datasethttp://www.invernesssouth.com/uploads/1/8/2/9/18294681/bluefin_tuna_and_swordfish_science_projects_in_2016.pptx 2017-04-17, 10E36 AM

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Objectives:• To identify all

Bluefin tuna directedtrips

• To validate/correctkey variables (e.g.,date/time of sailing,capture and landing)

Year

% trips withcorrections

% rows withcorrections

2002

50.62 84.35

2003

47.95 94.69

2004

83.85 77.56

2005

71.91 65.88

2006

70.09 67.14

2007

66.41 59.50

20072.88 72.60

Comparison of New and PreviousDatasets

New dataset Previous dataset

Year # Effort Weight Nominal # Effort Weight Nominal


trips (kgs) CPUE trips (kgs) CPUE

2003

757 11945 235739 19.74 743 10697 224785 21.01

2004

1071 13792 237260 17.20 1063 13680 237070 17.33

2005

1431 15094 277620 18.39 1408 15010 277885 18.51

2006

1518 14932 358805 24.03 1490 14839 359154 24.20

2007

1054 11185 199365 17.82 1040 11253 200583 17.82

2008

1217 11974 244268 20.40 1216 12072 253499 21.00

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New sGSL Dataset (2003-2015)

• Designed for consistency with SWNS dataset• Added fields to better understand fishing

patterns and calculate effort (e.g., port sailed,licence id)


• Incorporated additional sources for validation/substitution (e.g., catch notification call, tunasummary landing)

• Included 5 missing trips

Initial Attempts to Calculate Effort

• Compiled key information (e.g., portcoordinates, time at sunrise/sunset)

• Developed rules to calculate effort (e.g., how toremove nights and steaming time)

• Complete for one day trips

Effort = trip length – time not spent targeting Bluefin


New Logbook Design ATLANTIC BLUEFIN TUNA LOG DOCUME

YEAR/ANNÉE

JOURNAL DE BORD POUR LE THONROUGE

A. GENERALINFORMATION RENSEIGNEMENTSGENERAUX B.

HOME MANAGEMENTAREA

C. HAIL AND LANDING INFORMATION/ RAPPORT PAR RADIO ET INFORMATION SUR LEDÉBARQUEMENT

RENSEIGNMENTSGÉNÉRAUX

ZONE DE GESTION DUPERMIS Y / A

M/

M

VESSELNAME NOM DUBATEAU

DATESAILED DATEDEDÉPART

HR.

MI

N.

VESSELVRN NEB

GNB

PEI

SMB

TIMESAILED HEUREDEDÉPART

AM

N-B(G)

I-P-E BSM PM

LICENCE# NO DEPERMIS

GNS

PORTSAILED PORTDUDÉPART

N-E(G)

HAIL OUTCONFIRMATION # NO DECONFIRMATIONDE PRÉAVIS DEDÉPART

NF

QC

SF

WHARFSAILED QUAIDEDÉPART

T-N QC SF

HAIL IN CONFIRMATION # NO DECONFIRMATION DE PRÉAVIS

DRAFT


DE RETOUR

Improvements to Logbook

1. Restructured fields (trip → set)

➢ Total hours fished, Gear used, size and make ofhook, # of lines fished, gauge of monofilament,bait used (species), position of fishing, statisticalunit area

2. Added fields

➢ Set #, Null set (Y/N), # by-catch, Strategy, Baitcondition, Other logs completed

3. Deleted fields

Improvements to Logbookhttp://www.invernesssouth.com/uploads/1/8/2/9/18294681/bluefin_tuna_and_swordfish_science_projects_in_2016.pptx 2017-04-17, 10E36 AM

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1. Modified instructions

➢ Ensured all fields are mentioned, improved uncleardefinitions

E. CATCH INFORMATION

ON THIS PORTION OF THE DOCUMENT, EACH LINE SHOULD CONTAIN INFORMATION ON ONE BLUEFIN TUNA CAUGHT, ONE BY-CATCH SPECIES CAUGHT, OR A NO

CATCH SET. RECORD ALL POSSIBLE INFORMATION FOR NO CATCH SETS. ALL FISH CAUGHT AND ALL FISH CAUGHT AND DISCARDED IN A TRIP SHOULD BE

ENTERED. FOR DISCARDED FISH, INDICATE IF THEY ARE RELEASED DEAD OR ALIVE IN COMMENTS. IF THERE IS NOT ENOUGH SPACE FOR ALL FISH CAUGHT

AND/OR NO CATCH SETS, PLEASE USE ADDITIONAL SHEETS. RECORD SET # SEQUENTIALLY, BEGINNING WITH 1. DATE AND START TIME CORRESPOND TO THE

BEGINNING OF A SET, WHEN FISHING GROUNDS HAVE BEEN REACHED. A SET ENDS (END TIME) WHEN FISH ARE HOOKED / HARPOONED, SEARCHING CEASES, OR

THERE IS A PAUSE IN FISHING (E.G., TO CHANGE GEAR). A SET DOES NOT INCLUDE STEAMING TIME, SWIMMING OR FIGHTING FISH, OR FISHING FOR BAIT. FOR

SETS WITH CATCH, RECORD THE SPECIES CAUGHT (I.E. BLUEFIN, BIGEYE, YELLOWFIN, ALBACORE), THE ENFORCEMENT TAG NUMBER FOR BLUEFIN TUNA (BFT

TAG #), AND THE COUNT OF OTHER SPECIES CAUGHT (# BY-CATCH). IF NO FISH WERE CAUGHT DURING A SET, PUT A CHECKMARK IN THE NO CATCH SET

COLUMN. RECORD THE LOCATION WHERE FISH WERE CAUGHT OR THE APPROXIMATE LOCATION WHERE MOST FISHING OCCURRED DURING A NO CATCH SET INPOSITION OF FISHING AND STATISTICAL UNIT AREA (SEE MAP ON PAGE 4 FOR UNIT AREAS). FOR POSITION OF FISHING, ENSURE THAT THE LATITUDE AND

LONGITUDE ARE NOTED IN DEGREES MINUTES SECONDS (DDMMSS). FOR EACH SET, SPECIFY THE GEAR USED (TENDED LINE, ROD AND REEL, ELECTRIC

HARPOON, TRAP), FISHING STRATEGY (CHUMMING, TROLLING), HOOK SIZE, HOOK TYPE, # OF LINE FISHED, GAUGE OF MONOFILAMENT OF LEADER LINE,BAIT USED SPECIES AND BAIT USED CONDITION (LIVE, DEAD, ARTIFICIAL). RECORD THE ESTIMATED ROUND WEIGHT FOR EACH BLUEFIN TUNA OR BY-CATCH

SPECIES IN KILOGRAMS (KG) IN THE HAIL WEIGHT COLUMN. THESE ARE THE WEIGHTS PROVIDED DURING THE HAIL IN CALL. IF THE FISH IS LANDED ROUND,BOTH THE ROUND AND DRESSED WEIGHTS (IN KG) MEASURED BY THE DOCKSIDE MONITORS SHOULD BE INCLUDED IN ACTUAL WEIGHT. RECORD PRICE PER KG

PROVIDED BY THE BUYER. PROVIDE BOTH FLANK LENGTH AND DRESSED LENGTH IN CENTIMETERS (CM) FOLLOWING THE MEASURING INSTRUCTIONS BELOW.NOTE THAT THE FLANK LENGTH MUST BE TAKEN BEFORE THE FISH IS DRESSED. INCLUDE SURFACE WATER TEMP. (! f) WHERE FISH WERE CAUGHT OR WHERE

MOST FISHING OCCURRED DURING A NO CATCH SET. IN ADDITION TO DISCARDS, THE COMMENTS SECTION SHOULD CONTAIN INFORMATION ON GEAR DETAILS,WEATHER, OTHER SIGHTINGS OF FISH, ETC.

Example section


COMMENTS, QUESTIONS?The End


SOME INTERESTING RESULTS

Stock Mixing Science John Graves, VIMSThe extent of movements of school-sized (ages 1-4) bluefin tuna betweenwestern North Atlantic (waters off thecoastal United States) and easternNorth Atlantic (Mediterranean Sea)using organochlorine pollutantcompounds as biogeochemical tracers . Approximately, 30% of school-agedbluefin tuna caught in the westernAtlantic are recent migrants. The muchlarger population size of the easternAtlantic stock limits our ability to


observe west to east migrant fish (i.e.,the probability of catching the one bluefish in the right portion of the graphabove is very low).

Discovery of a Spawning Ground• 2013 July spawning

in the Slope Sea• 6 to 18 days old

larvae• Well outside the

Gulf of Mexico andlater in the year


PROPOSED FOR 2017


2017 Work Plan• Abundance indicators

– CPUE for 2017 BFT assessment– CPUE for 2017 SWO assessment (Canadian &

USA/Canadian)– Length-based indicators for SWO and BFT

assessment

• Meetings (~17% of the year plus prep time) • Sampling

– For age composition (ALK)

Potential IGS Projects


• Stock Origin AnalysisProcess archived samples (~2900) to providemixing rate estimates by age for entire timeperiod of the fishery.

• Bycatch EstimationEstimate discard amounts for Shortfin Mako,Bluefin tuna, Blue Shark, Porbeagle, juvenileSwordfish, Loggerhead and Leatherback turtlesusing approach recommended in the 2016

Potential CA Projects

1. Stock Origin Analysis(43.5K)Process archived samples (~2900) to provide mixingrate estimates by age for entire time period of the


fishery.1. Isotope analysis ($15.00/sample = 13.5K)2. Genetic analysis ($25.00 to 15/sample = 30K)

2. Diet analysis of 2016 samples

($15.00/sample = 6K)


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