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Nearshore fish in the Chukchi Sea, Alaska · PDF file NNearshore Fish in the Chukchi Sea, Alaskaearshore Fish in the Chukchi Sea, Alaska Objectives In nearshore waters of the Chukchi

Jun 26, 2020

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  • Nearshore Fish in the Chukchi Sea, AlaskaNearshore Fish in the Chukchi Sea, Alaska Objectives

    In nearshore waters of the Chukchi Sea: • Identify distribution and relative abundance of fi sh Establish• baseline for long-term Arctic monitoring Collect and archive fi sh for energetic, genetic, and • voucher specimens

    Sample design August 2007- 2009 &

    6 stations

    2 bottom trawl tows &

    Methods

    Bottom trawl towsBeach seine hauls

    Environmental conditions

    Capelin

    Sea ice break-up

    Timing of ice break-up varied among years•

    June 2007 August 2008 July 2009

    Barrow Sea Ice Cam images

    Arctic cod

    Dominant fish

    earlyearly latelate moderatemoderate

    2008

    Species composition & catch

    Seine

    Trawl

    2007 2009

    n = 98 n = 1,465 n = 246

    Arctic cod

    Arctic cod

    other spp.

    Sculpins Sculpinsother spp.

    n = 5,779 n = 415 n = 2,387

    Capelin Capelin

    other spp.

    Sand lanceSculpins

    coldcoldwar m

    war m

    Sea surface temperature (SST)

    • Mean annual August SST related to ice break-up timing

    oC -2 0 642 8 10 12 14

    AOOS imagesAOOS images

    20072007 study area

    warmwarm x x == 9 9°°

    2009

    moderate moderate x = 6°°

    o

    ==

    20082008

    coldcold x x == 2 2°°

    Pacifi c sand lance

    Sculpin spp.

    Results

    n = 98 n = 1,465 n = 246

    Arctic cod

    Arctic cod

    other spp.

    Sculpins Sculpinsother spp.

    n = 5,779 n = 415

    n = 1,412

    Capelin Capelin

    other spp.

    Sand lanceSculpins

    Sept. 2009mod erat

    e mod

    erat e

    Capelin

    Arctic cod

    n = 6,449

    • Capelin most abundant in warm year (2007) and in September • Arctic cod most abundant in cold year (2008) and in September • Catch and species composition differed in 2009 between Aug. and Sept.

    mod erat

    e mod

    erat e

    Saffron cod

    September 2009

    1 seine haul/station

    Slender eelblenny

    Beaufort Sea

    Chukchi Sea Barrow

    Cooper Island

    Arctic cod

    Seine

    Other spp. 18%

    Capelin 82%

    Trawl

    Catch by gear

    • Dominant species differed by gear type

    Capelin

    other spp.

    Beach seine

    8 m depth trawl

    trawl 5 m depth

    Alaska

    0 15 km105

    represent the views or offi cial position of the Department of Commerece, NOAA, or NMFS. The recommendations and general content presented in this poster do not necessarily

    Total catch

    % T

    ot al

    c at

    ch

    Arctic cod

    Capelin

    26 species

    n = 19,147 fi sh

    10%

    21%

    69%

    Annual catch

    • Abundance varied by

    Trawl Seine

    2008 - cold 2007 - warm

    2009 - moderate

    Chukchi Sea

    year and gear type

    John F. Thedinga, Scott W. Johnson, and A. Darcie Neff NOAA Fisheries, Auke Bay Laboratories, Juneau, Alaska

    Chris A. Hoffman U.S. Army Corps of Engineers, Alaska District

    • Capelin and Arctic cod are abundant in nearshore waters of the Chukchi Sea • Sea ice conditions affect the distribution and abundance of nearshore fi sh Fish abundance and species composition varied monthly and annually•

    ConclusionsConclusions Mostly juveniles

    Other spp. 44%

    Arctic cod 56%

    Gulf of Alaska

    Bering Sea

    Arctic Ocean

    Study area