Good Cop Bad Cop The Art of Interrogation

Good Cop / Bad Cop The Art of Interrogation in Fisheries Management Dion Oxman Mark, Tag, and Age Lab Alaska Dept. Fish and Game Juneau, Alaska

WHERE DO CHINOOK & CHUM CAUGHT AS BYCATCH COME FROM? ● Wild or Hatchery Fish? ● How did these fish end up as bycatch? – Migration Patterns ● Juveniles or Adults (e. g. reproductively active)? – Age Composition 2

TAGS & MARKS CAN HELP ANSWER THESE QUESTIONS Coded Wire Tags (CWTs) Thermally Marked Otoliths Chinook Salmon Chinook & Chum Salmon Scales and Otoliths (Both Species) 3

Coded Wire Tags (CWTs) – Chinook Salmon Hatchery vs. Wild ● Birth date / Age ● Country of Origin ● State of Origin ● Hatchery of Origin ● Release Location ● 1. 1 mm # Hatchery Chinook 5 -yr average (2014 – 2018) % = Proportion CWT’d 4

CWT not externally visible so. . . Adipose Clip Adipose Fin Each CWT’d Chinook usually given an external mark to indicate it has a CWT. . . Adipose Clips! Not all Clipped Chinook have CWTs (Washington State) 5

Code entered into relational DB to determine hatchery origin & age. 6

Hatcheries release fish in many areas: CWTs also provide info Re: Migration ● Each release group w/unique CWT code Movements ● Consequently, each code provides origin Pop. structure and age for each release group But what do we do with the fish heads? 7

Otolith Thermal Marking: Chinook & Chum What is an Otolith (“ear stone”)? Inner Ear ● Hearing ● Balance ● Orientation ● Why Mark Otoliths? Development Sensitive to Environmental & Biological Change: Easy to Mark! Incremental Growth ● Biologically Inert = Permanent ● Bilaterally Symmetrical ● Birth Date ● Age ● Country of Origin ● State of Origin ● Hatchery of Origin ● Release Site ● 8

How Are Otoliths Thermally Marked? ● Dark ring created by a rapid change in temperature of at least 3 0 C ● Sequence of temperature changes = Unique Mark Patterns Time (24 h cycle) Temp 4, 4 n. H 5 H 4 9

Canada Korea Japan Russia U. S. Conservation of salmon in the high seas of the North Pacific Ocean # Hatchery Fish 5 -yr average (2014 – 2018) % = Proportion Thermal Marked 10

# Hatchery Fish 14% 2016 % = Proportion Thermal Marked 33% 15% 91% 23% 11

Otolith Mark & Recovery Mark Assignments ● Patterns unique within species ● Patterns unique across States & Countries Thermal Marking @ 3 to 6 weeks of age Vouchers ● Verify Mark Assignment ● NPAFC Image database 12

Thermal Mark Recovery Brain Otoliths 13

Otolith mounted in resin & polished until mark is visible. Mark Patterns entered into a relational DB to determine hatchery of origin and age. 14

Uses of Mark and Tag Recovery Data • • • Assess hatchery contribution to a fishery Real-Time Fishery Management (Open/Close) Assess survival of hatchery fish Stock Identification Population Estimation Movement & Migration Patterns 15

Age Estimation Why? ● Stock Assessment ● Pop. Demography ● Growth ● Longevity & Survival How? Count Growth Rings on incrementally grown hard parts of wild and hatchery fish Otoliths Scales 16

Knowledge of Life History and seasonal changes in growth rate helps interpret growth patterns Chinook Salmon – First 1 to 3 years in freshwater before moving to the ocean – Expect freshwater (slow) growth patterns Chum Salmon – Enter ocean soon after hatching – No Freshwater Growth 17

Chinook Freshwater & Marine Growth 1. 4 SW 3 Slow Growth (autumn/winter) Enhanced Growth (Spr/Sum) SW 2 1 Year (Annulus) Salt Water 1 Fresh Water 1 Slow freshwater growth Origin/Focus 18

Use of Scales and Otoliths • • Species identification Age and age composition Length at Age Distributions Growth studies Age-specific bycatch (AEQ Analyses) Age-specific stock composition Spatio-temporal modeling Marine mortality estimates 19

GENETICS CWTs Application No Yes THERMAL MARKS Yes % Marked 100% 1 in 10 100% Yes Difficult No Easy Relative Sample #s Low High Age Estimation No Yes All Fish Hatchery Movements Validation Special Training/Equip Sample Processing Stock ID Chinook otoliths Large = lots of prep time so CWTs may be preferred 20

CWT sampling Chinook caught in the BSAI and GOA fisheries 5 year average (2013 -2017) Fishery BSAI groundfish GOA rockfish # Sampled 1 # Adipose Clipped 1 # CWTs % sample with CWT 2, 077 48 17 0. 8% 2, 860 408 116 4. 1% 802 120 39 4. 9% 1 Number from the Fisheries Monitoring and Analysis Division of the Alaska Fisheries Science Center. Courtesy of Michelle Masuda (NOAA). 21

Origins of Chinook caught in 2017 GOA rockfishery N = 299. Complete Census (Julie Bonney et al. NOAA) THERMAL MARK RECOVERY (ADFG) ■ 294 otoliths ■ 24 Thermal marked = 8% Hatchery ■ Specific Ages known (Marks) ■ Specific Hatchery Origins Known (12 unique release groups from 6 hatcheries) hatcheries ■ Origins of unmarked fish (92%) = ? ? ? Origin (Marked Only) Willamette, OR Central WA Vancouver Island, BC Southeast, AK Southcentral, AK Unknown 8% 4% 38% 4% 8% GSI (Guthrie et al. NOAA) ■ 280 Genetic Samples ■ 280 Genetically marked! (100%) ■ No ages from genes (Scales, Otos) ■ Specific Origins Unknown ■ % Hatchery Unknown Origin West Coast US BC Southeast AK NW GOA Copper River 56% 28% 11% 3% 2% 22

Modeling Coastwide CWT Recoveries Across Space and Time to Build an Ocean Distribution Model for Chinook Salmon (J. Watson et al. ) - AFSC; NWFSC; AK Pacific University Recoveries of Chinook from Prosser Hatchery, Upper Columbia R. (n = 387) Model will help Inform 1) bycatch distributions 2) stock-specific impacts from bycatch Data: Regional Mark Information System (RMIS) Map Courtesy of Genoa Sullaway (NOAA NWFSC) 23

AK CWT Recoveries - Bering Sea and GOA Trawl Fisheries 1980 - 1990 2000 - 2016 Data: Regional Mark Information System (RMIS) Map Courtesy of Genoa Sullaway (NOAA NWFSC) ■ Specific Origins of CWTs not shown. ■ Release locations of these CWTs will be used to create ocean distributions models.

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