Northern Bering Sea Juvenile Chinook Salmon Survey - Phase 1

Salmonid Research, Monitoring, and Evaluation (RM&E)

Project ID	AK44211
Recovery Domains	-
Start Date	07/01/2016
End Date	11/30/2018
Year	2015
Status	Completed
Last Edited	01/31/2024

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Description

This project sampled 35 stations in the northeastern Bering Sea (NBS) for juvenile Chinook salmon (Oncorhynchus tshawytscha) using surface trawl gear in 2017. Almost 200 juvenile Chinook salmon were caught and processed for length, weight, and genetics, and a subset was retained for diet and energy density analyses. The total NBS, total Yukon River, and Canadian-origin Yukon River juvenile Chinook salmon abundance estimates were 2,480,000 (S.D. = 439,000), 1,774,000 (S.D. = 338,000), and 1,049,000 (S.D. = 207,000), respectively, which were below corresponding 2003–2016 averages. NBS juvenile Chinook salmon data through 2017 were used to develop forecasts of adult Yukon River runs from 2018–2020. Based on recent juvenile catches, total Yukon and Canadian-origin Chinook salmon adult runs in 2018–2020 are expected to be below average. Run sizes of this magnitude have the potential to meet escapement objectives and provide for some subsistence harvest opportunity, but may require some level of management restriction. These data were provided to Yukon area stakeholders and managers prior to the 2018 salmon season. Diet analyses from 2017 found that juvenile Chinook salmon primarily ate fish (88% of their diet by weight), but also ate crab larvae, zooplankton, squid, and insects. Energy density analysis results showed that 2017 juvenile Chinook salmon had the highest mean energy density (22.3 kJ/g), after controlling for fish length, since 2006.

This project utilized funds from PCSRF grants NA13NMF4380259; no funds from this grant were used beyond June 30, 2018.

Project Benefit

Chinook salmon are a key subsistence stock in the AYK region. Data from this project will assist efforts to reduce uncertainty in the production dynamics of Yukon River Chinook salmon and benefit their overall management. The NBS survey will provide a juvenile abundance estimate, which will inform a pre-season run forecast estimate for Canadian-origin Yukon River Chinook. As Norton Sound Chinook salmon run sizes are small, it is unlikely that a comparable run forecast tool could be developed for Norton Sound, but attempts will be made to evaluate the utility of a juvenile-based forecast for these stocks as well.

Source

Funds

PCSRF

$327,991

State

$115,293

Report Total:

$443,284

Worksites

Northeast Bering SEa

Worksite Identifier: Northeast Bering SEa
Start Date:
End Date:

Area Description

No Area Description data was found for this worksite.

Location Information

Basin:
Subbasin:
Watershed:
Subwatershed:

State:
Recovery Domain:
Latitude: 62
Longitude: -168

ESU

Un-Named ESU Chinook

Map

Photos

Metrics

E.0 Salmonid Research, Monitoring, and Evaluation (RM&E)Y (Y/N)

. . E.0.a RM&E Funding 443,284.00
. . E.0.b
Complement habitat restoration project
. . E.0.c
Project identified in a plan or watershed assessment.
. . E.0.d.1 Number of Cooperating Organizations 0
. . E.0.d.2
Name Of Cooperating Organizations.

None
. . E.0.e.1 Number of reports prepared 2

. . E.0.e.2

Name Of Report

Howard, K.G., Garcia, S., Murphy, J., and T.H. Dann (in publication). 2019. Northeastern Bering Sea Juvenile Chinook Salmon Survey, 2017. Alaska Department of Fish and Game, Fishery Data Series No. YY-XX, Anchorage. Garcia, S. and F. Sewall (in review). 2019. Diet and energy density assessment of juvenile Chinook salmon from the northeastern Bering Sea, 2004-2017. Alaska Department of Fish and Game, Fishery Data Series No. YY-XX, Anchorage.

. . E.1 MonitoringY (Y/N)

. . . . E.1.a Monitoring funding 341,199.00
. . . . E.1.b.1 Stream Miles Monitored .00
. . . . E.1.b.2 Acres of Watershed Area Monitored .0
. . . . E.1.b.3 Square miles of water monitored37932 (Square miles)
. . . . E.1.c.2 Salmonid smolt or fry monitoringY (Y/N)
- . . . . . . E.1.c.2.a # miles (to nearest 0.01 mile) monitored for Salmonid smolt or fry .00
- . . . . E.1.d
  Name Of Comprehensive Monitoring Strategy/Program

. . E.2 ResearchY (Y/N)

. . . . E.2.a Research Funding 102,085.00

. . . . E.2.b.1 Modeling and data analysisY (Y/N)

. . . . . . E.2.b.1.a

Key issues addressed by modeling and data analysis research

This project sampled juvenile Chinook salmon in the northeastern Bering Sea using surface trawl gear in 2017. Genetic mixed stock analysis was used to estimate stock-specific juvenile abundance for Canadian-origin and Total Yukon Chinook salmon. Stock-specific estimates of juvenile abundance were used to forecast future Yukon River Chinook salmon run size. The forecasted adult runs for 2018-2020 produced from this project were provided to fishery managers and stakeholders prior to the 2018 salmon season. The forecasts generated from this project provide an indicator of Chinook salmon productivity up to three years in advance.