inter-annual distribution of yukon river juvenile chum salmon in … · 2015-06-30 · the yukon...

Inter-annual distribution of Yukon River juvenile chum salmon in the eastern Bering Sea C. Kondzela 1 , C. Marvin 1 , J. Whittle 1 , H. Nguyen 1 , J. Murphy 1 , E. Farley 1 , K. Howard 2 , B. Borba 3 , W. Templin 2 , and J. Guyon 1 1 Auke Bay Laboratories, Alaska Fisheries Science Center, NMFS, NOAA, Juneau, Alaska 2 Alaska Department of Fish and Game, Anchorage, Alaska, 3 Alaska Department of Fish and Game, Fairbanks, Alaska Introduction The Yukon River has two distinct runs of chum salmon: a more abundant summer-run and a less abundant fall-run. Concern about fall-run chum salmon abundance in some years has reduced fishing opportunities on the Yukon River. Little is known about the survival of juvenile Yukon River chum salmon in their freshwater or saltwater environments. Previous analyses with allozymes indicate that juvenile chum salmon on the eastern Bering Sea shelf, north of 60°N, were predominantly from the Yukon River. Question 1 What is the origin of juvenile chum salmon on the eastern Bering Sea shelf off the mouth of the Yukon River and does it vary across years? Funded by: NOAA, Alaska Sustainable Salmon Fund, Project 44619 and Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative, Project 1002/SAF-336. The recommendations and general content presented in this poster do not necessarily represent the views or official position of the Department of Commerce, the National Oceanic and Atmospheric Administration, or the National Marine Fisheries Service. Genetic analyses More than 5,000 samples genotyped for 11 microsatellite loci. Stocks identified with the BAYES program and a 381-population genetic baseline (Fisheries and Oceans Canada). Samples Juvenile chum salmon were collected on the eastern Bering Sea shelf off the mouth of the Yukon River, between 58-65°N, during the 2003- 2007 U.S. BASIS cruises. 0.20 0.25 0.30 0.35 0.40 0.45 0.20 0.25 0.30 0.35 0.40 0.45 0.50 Adults returns (abundance estimates) Juveniles at sea (genetic analysis) Ratio Fall:Summer '02 '04 '05 '06 '07 '03 r = 0.85 P = 0.03 Allozyme markers NPAFC International Symposium on Pacific Salmon and Steelhead Production in a Changing Climate: Past, Present, and Future May 17-19, 2015 Kobe, Japan Conclusions • Juvenile chum were mostly from coastal western Alaska and upper-middle Yukon populations. • Regional stock contributions were generally similar year- to-year, even with latitudinal shifts in catch distribution. • Juvenile chum from western Alaska migrate west and south across the eastern Bering Sea shelf. • The proportion of fall-run juveniles is correlated with brood-year returns. • Yukon River summer and fall-run chum salmon proportions are determined early in the first year of life. Yukon River Kuskokwim River Bristol Bay Norton Sound Sampling juvenile chum salmon at sea. NOAA, AFSC, ABL, EMA Program Yukon summer Yukon fall Norton Sound Kuskokwim- Bristol Bay Yukon River Kuskokwim River Bristol Bay Norton Sound Yukon River Kuskokwim River Bristol Bay Norton Sound Yukon River Kuskokwim River Bristol Bay Norton Sound Yukon River Kuskokwim River Bristol Bay Norton Sound 2003 2004 2005 2006 2007 Question 2 Is there a correlation between juveniles at sea and adult returns in the relative abundance of fall and summer run Yukon River chum salmon? Yukon River Kuskokwim River Bristol Bay Norton Sound Yukon River Kuskokwim River Bristol Bay Norton Sound Yukon River Kuskokwim River Bristol Bay Norton Sound Yukon River Kuskokwim River Bristol Bay Norton Sound Yukon River Kuskokwim River Bristol Bay Norton Sound

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Page 1: Inter-annual distribution of Yukon River juvenile chum salmon in … · 2015-06-30 · The Yukon River has two distinct runs of chum salmon: a more abundant summer-run and a less

Inter-annual distribution of Yukon River juvenile chum salmon in the eastern Bering Sea

C. Kondzela1, C. Marvin1, J. Whittle1, H. Nguyen1, J. Murphy1, E. Farley1, K. Howard2, B. Borba3, W. Templin2, and J. Guyon1 1Auke Bay Laboratories, Alaska Fisheries Science Center, NMFS, NOAA, Juneau, Alaska

2Alaska Department of Fish and Game, Anchorage, Alaska, 3Alaska Department of Fish and Game, Fairbanks, Alaska

Introduction

The Yukon River has two distinct runs of chum salmon: a more abundant summer-run and a less abundant fall-run.

Concern about fall-run chum salmon abundance in some years has reduced fishing opportunities on the Yukon River.

Little is known about the survival of juvenile Yukon River chum salmon in their freshwater or saltwater environments.

Previous analyses with allozymes indicate that juvenile chum salmon on the eastern Bering Sea shelf, north of 60°N, were predominantly from the Yukon River.

Question 1

What is the origin of juvenile chum salmon on the eastern Bering Sea shelf off the mouth of the Yukon River and does it vary across years?

Funded by: NOAA, Alaska Sustainable Salmon Fund, Project 44619 and Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative, Project 1002/SAF-336. The recommendations and general content presented in this poster do not necessarily represent the views or official position of the Department of Commerce, the National Oceanic and Atmospheric Administration, or the National Marine Fisheries Service.

Genetic analyses

More than 5,000 samples genotyped for 11 microsatellite loci.

Stocks identified with the BAYES program and a 381-population genetic baseline (Fisheries and Oceans Canada).

Samples

Juvenile chum salmon were collected on the eastern Bering Sea shelf off the mouth of the Yukon River, between 58-65°N, during the 2003-2007 U.S. BASIS cruises.

0.20

0.25

0.30

0.35

0.40

0.45

0.20 0.25 0.30 0.35 0.40 0.45 0.50

Adults

retu

rns

bundan

ce e

stim

ates

)

Juveniles at sea (genetic analysis)

Ratio Fall:Summer

'02

'04

'05

'06

'07 '03

r = 0.85 P = 0.03

Allozyme markers

NPAFC International Symposium on Pacific Salmon and Steelhead Production in a Changing Climate:

Past, Present, and Future May 17-19, 2015

Kobe, Japan

Conclusions • Juvenile chum were mostly from coastal western Alaska

and upper-middle Yukon populations. • Regional stock contributions were generally similar year-

to-year, even with latitudinal shifts in catch distribution. • Juvenile chum from western Alaska migrate west and south across the eastern Bering Sea shelf.

• The proportion of fall-run juveniles is correlated with brood-year returns. • Yukon River summer and fall-run chum salmon proportions are determined early in the first year of life.

Yukon River

Kuskokwim River

Bristol Bay

Norton Sound

Sampling juvenile chum salmon at sea. NOAA, AFSC, ABL, EMA Program

Yukon summer Yukon fall

Norton Sound Kuskokwim- Bristol Bay

Yukon River

Kuskokwim River

Bristol Bay

Norton Sound

Yukon River