Early Marine Ecology of Juvenile Chinook Salmon

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

Project ID1330
Recovery Domains -
Start Date05/01/2013
End Date05/31/2016
Last Edited07/28/2021
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Under this project, salmon sampling within the lower Yukon River was designed to replicate and expand on the work of Martin et al. (1987). Salmon were sampled in 2014 and 2015 from all three of the lower Yukon River tributaries using a surface trawl net. Sampling began shortly after ice-out in May and continued until the end of July, and stations were sampled three times per week. Additionally, salmon were sampled along the delta front in June, July and August of 2014 and 2015 using surface- and mid-water trawls. Sampling locations were selected to maximize spatial coverage around the delta, allow sampling across the freshwater/marine transition of the Yukon River plume, and to maintain project cost. Captured fish were identified to species, and a minimum of 30 fish (distributary) and 50 fish (front) of each species were measured. Chinook, coho, and chum salmon specimens were preserved for laboratory analysis. Genetic samples were collected from Chinook and coho salmon. Fish that could not be identified to species in the field were photographed, vouchered, and returned to the laboratory for identification. In the laboratory, each salmon was weighed and sagittal otoliths and stomach contents collected for analysis. A total of 381 juvenile Chinook salmon were analyzed for energy content: 155 distributary and 7 front for 2014 and 204 distributary and 15 front for 2015. A total of 949 juvenile Chinook salmon were evaluated for stomach fullness; 337 tributary and 17 front specimens from 2014, and 555 and 40 from 2015. Diet analyses were also conducted on a total of 388 juvenile coho salmon.

Project Benefit    

This research will update juvenile life-history data on the timing and size of marine entry under current climate conditions. This research will augment existing data on the marine ecology of juvenile Chinook salmon in the northern Bering Sea by providing seasonal distribution, size, and condition information prior to their capture in eastern Bering shelf (BASIS) surveys. This research investigates a period in the life of juvenile Yukon Chinook salmon that is expected to be highly influential to cohort return strength.


Metric Completed Originally

Funding Details

In-Kind Donated Labor$196,493
Report Total:$912,576

Project Map



  • Worksite Identifier: 37257124
  • Start Date: 05/01/2013
  • End Date: 06/30/2016
Area Description
Yukon River Delta

Location Information

  • Basin:
  • Subbasin:
  • Watershed:
  • Subwatershed:
  • State: Alaska
  • Recovery Domain:
  • Latitude: 62.5909638778
  • Longitude: -164.89151000975255


  • Un-Named ESU Chinook




  • E.0 Salmonid Research, Monitoring, and Evaluation (RM&E)Y (Y/N)
    •      . . E.0.a RM&E Funding 912,576.00
    •      . . E.0.b
      Complement habitat restoration project
    •      . . E.0.c
      Project identified in a plan or watershed assessment.
      Schindler, D., Krueger, Bisson, Bradford, Clark, Conitz, Howard, Jones, Murphy, Myers, Scheuerell, Volk, Winton. Arctic-Yukon-Kuskokwim Chinook Salmon Research Action Plan: Evidence of Decline of Chinook Salmon, AYK SSI, Aug 2013
    •      . . E.0.d.1 Number of Cooperating Organizations 4
    •      . . E.0.d.2
      Name Of Cooperating Organizations.
      Alaska Department of Fish and Game (ADFG) National Marine Fisheries Service (NMFS) Yukon Delta Fisheries Development Association (YDFDA) Association of Village Council Presidents (AVCP)
    •      . . E.0.e.1 Number of reports prepared 2
    •      . . E.0.e.2
      Name Of Report
      K.G. Howard, K. Miller, J. Murphy. Reports undergoing agencies internal reviews. Fishery Data Series No. YY-XX Estuarine Fish Ecology of the Yukon River Delta, 2014-2015, AK Dept. of Fish & Game. NOAA Technical Memorandum, Spatial distribution, diet, and nutritional status of juvenile Chinook salmon and other fishes in the Yukon River estuary NMFS, Alaska Fisheries Science Center, Auke Bay Laboratories. PDF format.
    •      . . E.2 ResearchY (Y/N)
      •      . . . . E.2.a Research Funding 912,576.00
      •      . . . . E.2.b.4 Life history studyY (Y/N)
        •      . . . . . . E.2.b.4.a
          Key issues addressed by life history research