Potential Effects of Mark-Selective Fisheries on Central Valley Salmon Brian Pyper and Steve Cramer Cramer Fish Sciences

ESA-listed stocks ESA-listed stocks –Minority of ocean Chinook –Protection from harvest is desired CV Fall Chinook CV Fall Chinook –Relatively abundant & do not need protection –89-95% of landings south of Pt Arena –50-90% from hatcheries & endure high harvest rates Strategies to reduce harvest on ESA stocks reduce harvest of abundant CV fall Chinook Strategies to reduce harvest on ESA stocks reduce harvest of abundant CV fall Chinook Crux of the Harvest Issues

What is Mass Marking and Mark Selective Fishing? Mark most or all hatchery releases of smolts by clipping the adipose fin Mark most or all hatchery releases of smolts by clipping the adipose fin Can CWT some or all marked smolts Can CWT some or all marked smolts Mass mark and tag with machines in trailers Mass mark and tag with machines in trailers Marked adults retained in fisheries; unmarked (natural origin) fish released Marked adults retained in fisheries; unmarked (natural origin) fish released Underway in the Pacific Northwest Underway in the Pacific Northwest

Northwest Marine Technology AutoFish System

Adipose Fin Clip CWT

Purpose: To develop costs and benefits of implementing mark-selective fisheries to protect winter and spring run Chinook and move toward the doubling goal Mark-Selective Fisheries Analysis Goals

Beneficiaries of Mark-Selective Fisheries In the California Ocean

Analysis Framework for mark-selective fisheries calculations Framework for mark-selective fisheries calculations Application to winter-run Chinook Application to winter-run Chinook Analysis of other runs Analysis of other runs –Sacramento fall and spring Chinook –San Joaquin fall Chinook –Past and future

Information Sources for Estimating Harvest Mortality Mortality rate of fish caught & released Mortality rate of fish caught & released High mortality for mooching included High mortality for mooching included Added mortality from multiple captures of released fish estimated Added mortality from multiple captures of released fish estimated Recent harvest rates on winter-run Chinook Recent harvest rates on winter-run Chinook

Winter-run Scenarios Fishery ScenarioNatural Fish Harvest Rate Hatchery Fish Harvest Rate Age 3Age 4Age 3Age 4 Baseline (Current Conditions)21.0%66.0%21.0%66.0% Mark Selective Fishery Current Harvest Rates (Catch-and-release mortality) 0% (4.8%) 0% (20.3%) 21.0%66.0% Mark Selective Fishery High Historical Harvest Rates (Catch-and-release mortality) 0% (10.8%) 0% (19.3%) 42.0%64.0%

Winter-run Results Winter Run Escapement under Alternative Harvest Scenarios 0 10,000 20,000 30,000 40,000 50,000 60, Simulation Year Baseline (Current Conditions) Mark Selective (Current Harvest Rates) Mark Selective (High Historical Harvest Rates) Change in Escapement at Year 12 Number of Chinook 38,600 31,500 21,500

Methods for Retrospective Analysis Examined implications of mark-selective using historic data (2001 – 2006) Examined implications of mark-selective using historic data (2001 – 2006) Coast-wide commercial and recreational catch of chinook Coast-wide commercial and recreational catch of chinook Assumed all unmarked fish released (with release mortality) Assumed all unmarked fish released (with release mortality) Key uncertainty: Proportion of hatchery versus wild fish Key uncertainty: Proportion of hatchery versus wild fish

Change in No. of Chinook (1,000s) Catch Escapement Retrospective - Change for CV Fall Chinook with 50% Harvest on Marked Fish with 50% Harvest on Marked Fish % Hatchery80% Hatchery

Change in No. of Chinook (1,000s) Catch Retrospective - Change for CV Fall Chinook with 50% Harvest on Marked Fish with 50% Harvest on Marked Fish 50% Hatchery80% Hatchery Escapement

Future Simulations of Aggregate Chinook Populations Three groups: Three groups: –Sacramento spring- and fall-runs –San Joaquin fall-run Ricker stock-recruit dynamics (examined multiple parameter values) Ricker stock-recruit dynamics (examined multiple parameter values) Age-structured Age-structured Separate components Separate components –Hatchery –Wild (natural) Compared fisheries Compared fisheries –“Traditional” (non-selective), and –Mass-marked mark-selective

Simulation Framework Wild spawners Hatchery Smolts Age-2 recruits Age-specific maturity and harvest rates Release mortality, drop-offs Landings,drop-offs spawners Brood take, spawners Fixedsurvival Spawners Recruits Replacement Ricker Model u = 1- (1-h) m Multiple encounters:

Simulation Results: Potential Escapement of Wild CV Chinook Natural Escapement with 50% Harvest Rate - 50, , , , , , , , ,000 SpringSacramento FallSan Joaquin Fall Potential Escapement Traditional Mark Selective

Simulation Results: Potential Catch of Wild CV Chinook Catch with 50% Harvest Rate - 100, , , , , , ,000 SpringSacramento FallSan Joaquin Fall Potential Catch Traditional Mark selective

Mass Marking and Tagging Feasibility? (Washington experience next session) Washington is making it work Washington is making it work Puget Sound Hatchery Chinook numbers Puget Sound Hatchery Chinook numbers –Similar to Central Valley –Currently mass marking ~20 M Chinook (>90%) Alternative to not fishing or to less fishing Alternative to not fishing or to less fishing Mark-selective fisheries operating in the Straight of Juan de Fuca Mark-selective fisheries operating in the Straight of Juan de Fuca California California –Untried –Next year - just 25% marking and tagging

If hatchery fish are > 50% of Chinook, then foregone harvest will be proportionally less If hatchery fish are > 50% of Chinook, then foregone harvest will be proportionally less Can estimate hatchery versus wild fraction Can estimate hatchery versus wild fraction Flexibility: Flexibility: –Allow harvesting of unmarked fish –When high concentrations of healthy stocks ESA-listed and other populations can benefit ESA-listed and other populations can benefit –California Coastal Chinook –Coho –Klamath More Potential Benefits of MSF

Simulation results: Catch of Wild CV Chinook Catch with 50% Harvest Rate - 100, , , , , , ,000 SpringSacramento FallSan Joaquin Fall Catch Future? Selective ? ??