HistoryHistory

Need to mark fish to get survival & exploitation Need to mark fish to get survival & exploitation rates for Treaty negotiations, to determine rates for Treaty negotiations, to determine differential survival of various release strategies differential survival of various release strategies & to determine distribution in fisheries & to determine distribution in fisheries

Started marking in BC with 1967 broodStarted marking in BC with 1967 brood Use alpha-numeric tags, mainly on chinook and Use alpha-numeric tags, mainly on chinook and

cohocoho Use fin clips, mainly on other species except Use fin clips, mainly on other species except

adipose clips on cohoadipose clips on coho

Types of MarkingTypes of Marking

Coded-wire tags (CWT)Coded-wire tags (CWT) Fin clips: adipose (Ad), right or left ventral Fin clips: adipose (Ad), right or left ventral

(RV/LV), right or left maxillary (RM/LM)(RV/LV), right or left maxillary (RM/LM) Otoliths (has rings like a scale)Otoliths (has rings like a scale) Calcein- fluorescent dye in finsCalcein- fluorescent dye in fins Passive-induced transponder (PIT) tagsPassive-induced transponder (PIT) tags

Tagging Pros & ConsTagging Pros & Cons

Lots of codes available- can identify Lots of codes available- can identify different stocks or release strategiesdifferent stocks or release strategies

Can get survival and exploitation rates for Can get survival and exploitation rates for individual stocks or release strategiesindividual stocks or release strategies

Application is expensiveApplication is expensive Recovery may be expensiveRecovery may be expensive

Fishery sampling is expensiveFishery sampling is expensive Escapement sampling may not be very Escapement sampling may not be very

expensive if at fence or hatchery rackexpensive if at fence or hatchery rack

Finclipping Pros and ConsFinclipping Pros and Cons

Can use as visual I.D.- for mass markingCan use as visual I.D.- for mass marking Application less expensive than CWTApplication less expensive than CWT Few options for distinguishable codesFew options for distinguishable codes Can’t get survival & exploitation ratesCan’t get survival & exploitation rates Higher mortality from ventral/maxillary Higher mortality from ventral/maxillary

clips than from taggingclips than from tagging Can’t determine age class if use same clip Can’t determine age class if use same clip

every year - need scales tooevery year - need scales too

Otolith Pros and ConsOtolith Pros and Cons

Very inexpensive to applyVery inexpensive to apply No external visual I.D.No external visual I.D. Few options for distinguishable codesFew options for distinguishable codes Sampling and reading of otoliths is Sampling and reading of otoliths is

expensiveexpensive Can’t determine age class if use same Can’t determine age class if use same

mark every year - need scales toomark every year - need scales too

Magnified OtolithMagnified Otolith

Number to Tag/MarkNumber to Tag/Mark

For coho fry, need to tag at least 40K for For coho fry, need to tag at least 40K for distribution, 80K for survival & exploitation distribution, 80K for survival & exploitation rates (lower survival on fry release)rates (lower survival on fry release)

Tag minimum 20K coho smolts or 75K Tag minimum 20K coho smolts or 75K chinook smolts for distribution in fisherieschinook smolts for distribution in fisheries

Tag 40K coho or 200K chinook smolts for Tag 40K coho or 200K chinook smolts for survival & exploitationsurvival & exploitation

For chum fry need minimum 100K finclips For chum fry need minimum 100K finclips

Costs of MarkingCosts of Marking

Tags cost $.09 per fishTags cost $.09 per fish Contractor AdCWT application costs about Contractor AdCWT application costs about

$.12 per fish$.12 per fish Adipose clip costs about $.05 per fishAdipose clip costs about $.05 per fish Tagging machines cost about $24,000 for Tagging machines cost about $24,000 for

the tag injector and $14,000 for the QCD the tag injector and $14,000 for the QCD (checks tag retention)(checks tag retention)

CWT Recovery Data AvailabilityCWT Recovery Data Availability

Mark Recovery Program (MRP) reports- Mark Recovery Program (MRP) reports- can get details down to exact sport catch can get details down to exact sport catch locations and recoveries by week and locations and recoveries by week and statistical area for commercial fisheriesstatistical area for commercial fisheries

SEP1 reports- Summary of fishery SEP1 reports- Summary of fishery recoveries with escapement data added; recoveries with escapement data added; includes survival & exploitation ratesincludes survival & exploitation rates

Tag Recovery DataTag Recovery Data# Observed# Observed

Observed is the number of a particular tag Observed is the number of a particular tag code actually found in a sample of fish in code actually found in a sample of fish in the catch or escapementthe catch or escapement

# observed in sport catch is # turned in or # observed in sport catch is # turned in or # found in creel survey# found in creel survey

Mark rate is the % tagged in the total Mark rate is the % tagged in the total sampledsampled

Tag Recovery DataTag Recovery Data# Estimated# Estimated

The # estimated accounts for tags in the The # estimated accounts for tags in the unsampled part of catch or escapementunsampled part of catch or escapement

Calculated as # observed / sample rateCalculated as # observed / sample rate Sample rate is % sampled of total catch or Sample rate is % sampled of total catch or

escapement (100% if all sampled)escapement (100% if all sampled) Aim for 20% sample rate in commercial Aim for 20% sample rate in commercial

fisheriesfisheries Use sport awareness factor (creel survey)Use sport awareness factor (creel survey)

Tag Recovery DataTag Recovery Data# Expanded# Expanded

The number expanded accounts for the The number expanded accounts for the unmarked fish released with a given tag unmarked fish released with a given tag groupgroup

It is calculated from the number estimated It is calculated from the number estimated / number released with tags * total number / number released with tags * total number released (in a given release group)released (in a given release group)

Example of Estimation and Example of Estimation and Expansion of Observed TagsExpansion of Observed Tags

Tag Code 18-28-11 (2000 brood Tag Code 18-28-11 (2000 brood Cowichan R chinook): 25,175 tagged of Cowichan R chinook): 25,175 tagged of 99,829 total release99,829 total release

Observed in 2003 escapement: 3 tags in Observed in 2003 escapement: 3 tags in dead pitch sample of 527 and total river dead pitch sample of 527 and total river spawners= 2,494spawners= 2,494

Estimated= 3/527*2,494= 14Estimated= 3/527*2,494= 14 Expanded= 14/25,175*99,829= 56Expanded= 14/25,175*99,829= 56

Information from Tagging/MarkingInformation from Tagging/Marking

Identification of hatchery fish Identification of hatchery fish Distribution in fisheries Distribution in fisheries Enhanced contribution Enhanced contribution Harvest or exploitation rate Harvest or exploitation rate Survival rateSurvival rate

Identification of Hatchery FishIdentification of Hatchery Fish

For use in brood stock collectionFor use in brood stock collection For use in hatchery mark-selective For use in hatchery mark-selective

fisheriesfisheries

Distribution in FisheriesDistribution in Fisheries

For interest- to see where a particular For interest- to see where a particular stock is caughtstock is caught

Determine what fisheries to close or Determine what fisheries to close or reduce to help preserve stocks of concernreduce to help preserve stocks of concern

Determine what stocks are caught in Determine what stocks are caught in mixed stock fisheriesmixed stock fisheries

Chinook Distribution in Fisheries Chinook Distribution in Fisheries and Escapement, 2000-2005and Escapement, 2000-2005

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Big Qualicum R Chilliwack R Conuma R Cowichan R Nanaimo R Nitinat R Quinsam R Robertson Cr

Stock

Esc

FreshSpt

WDFW

InsideSpt

InsideNet

WCVISpt

WCVITroll

WCVINet

NrthCenSpt

NrthCenNet

AK

SpecCode 124

Sum of Estimated

StockAbrev

ColName

Coho Distribution in Fisheries and Coho Distribution in Fisheries and Escapement, 2000-2005Escapement, 2000-2005

0%

20%

40%

60%

80%

100%

Big Qualicum R Capilano R Chilliw ack R Inch Cr Puntledge R Quinsam R Robertson Cr Tenderfoot Cr

Stock

% of

total

estim

ated r

ecov

eries

(C+E

)

Esc

FreshSpt

WDFW

InsideSpt

InsideNet

WCVISpt

WCVITroll

WCVINet

NrthCenSpt

AK

SpecCode 115

Sum of Estimated

StockAbrev

ColName

Enhanced ContributionEnhanced Contribution

Determine whether the hatchery Determine whether the hatchery component in a river has exceeded some component in a river has exceeded some target (50%)target (50%)

Determine how well the hatchery stock is Determine how well the hatchery stock is performing (in conjunction with survival performing (in conjunction with survival rate)rate)

Cowichan Chinook Enhanced Contribution in Brood Stock and River

0

20

40

60

80

10019

90

1992

1994

1996

1998

2000

2002

2004

2006

Return Year

% E

nhan

ced

Cont

ribut

ion

Removals

River Spawners

Cowichan Chinook Overall Enhanced Contribution

010203040506070

1990

1992

1994

1996

1998

2000

2002

2004

2006

Return Year

% E

nh

ance

d

Co

ntr

ibu

tio

n

Enh Cont

Harvest/Exploitation RateHarvest/Exploitation Rate

Harvest rate is the % of fish surviving to Harvest rate is the % of fish surviving to adulthood caught in one fisheryadulthood caught in one fishery

Exploitation rate is the overall % of fish Exploitation rate is the overall % of fish surviving to adulthood caught in all surviving to adulthood caught in all fisheriesfisheries

Determine harvest rates in individual Determine harvest rates in individual fisheries for each stockfisheries for each stock

Track harvest & exploitation rates to make Track harvest & exploitation rates to make sure we’re not over-fishingsure we’re not over-fishing

Coho Exploitation Rates

0

20

40

60

80

10019

87

1989

1991

1993

1995

1997

1999

2001

Brood Year

% E

xplo

itatio

n

Big Qualicum

Dunn Cr

Inch Cr

Robertson

Chinook Exploitation Rates

0

20

40

60

80

100

120

Brood Year

% E

xplo

itatio

n Cowichan

Dome Cr

Nanaimo

Robertson

Survival RateSurvival Rate

Determine differential survival for different Determine differential survival for different release strategiesrelease strategies

Determine differential survival for wild Determine differential survival for wild versus hatchery releasesversus hatchery releases

Track the trend in survival for warning of Track the trend in survival for warning of any problems developingany problems developing

Quinsam River SurvivalsQuinsam River Survivals

Smolt 0+ and Seapen 0+ (median seapen/smolt = 1.1)

-

0.2

0.4

0.6

0.8

1.0

1.2

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

Smolt 0+ Seapen 0+

Cowichan Chinook SurvivalCowichan Chinook Survival

Survival Smolt 0+ and Seapen 0+

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1991 1992 1993 1994 1995 1996 1997 1998 1999

Brood Year

2 late river5 seapen

Coho Survival Rates

0

2

4

6

8

10

12

14

1987

1989

1991

1993

1995

1997

1999

2001

Brood Year

% S

urv

ival Big Qualicum

Dunn Cr

Inch Cr

Robertson

Chinook Survival Rates

00.5

11.5

22.5

33.5

419

87

1989

1991

1993

1995

1997

1999

2001

Brood Year

% S

urvi

val Cowichan

Dome Cr

Nanaimo

Robertson