TY - JOUR
T1 - The vertical distribution of juvenile salmon (Oncorhynchus spp.) and associated fishes in the Columbia River plume
AU - Emmett, Robert L.
AU - Brodeur, Richard D.
AU - Orton, Philip M.
PY - 2004/11
Y1 - 2004/11
N2 - Simultaneous trawling at surface and at depth at one location off the Columbia River, Oregon, in June 2000 identified the depth distribution of juvenile salmonids and associated fishes. Juvenile salmon off the Columbia River were distributed primarily near the surface, within the upper 12 m. Highest densities of subyearling chinook salmon (Oncorhynchus tshawytscha) off the Columbia River were associated with high surface currents and decreasing tidal levels, with time of day possibly a co-factor. Densities of yearling chinook salmon increased with higher turbidity. Pacific herring (Clupea pallasi) was the most abundant and commonly caught forage fish, with density increasing at night, probably related to diel vertical migration. Catches of juvenile salmonids were not associated with catches of forage fishes. Daytime surface trawling appears to be an appropriate method for assessing the distribution and abundance of juvenile salmonids in marine habitats.
AB - Simultaneous trawling at surface and at depth at one location off the Columbia River, Oregon, in June 2000 identified the depth distribution of juvenile salmonids and associated fishes. Juvenile salmon off the Columbia River were distributed primarily near the surface, within the upper 12 m. Highest densities of subyearling chinook salmon (Oncorhynchus tshawytscha) off the Columbia River were associated with high surface currents and decreasing tidal levels, with time of day possibly a co-factor. Densities of yearling chinook salmon increased with higher turbidity. Pacific herring (Clupea pallasi) was the most abundant and commonly caught forage fish, with density increasing at night, probably related to diel vertical migration. Catches of juvenile salmonids were not associated with catches of forage fishes. Daytime surface trawling appears to be an appropriate method for assessing the distribution and abundance of juvenile salmonids in marine habitats.
KW - Columbia River
KW - Depth distribution
KW - Diel
KW - Pacific salmon
KW - Surface trawling
KW - Tides
UR - http://www.scopus.com/inward/record.url?scp=8744246270&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=8744246270&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2419.2004.00294.x
DO - 10.1111/j.1365-2419.2004.00294.x
M3 - Article
AN - SCOPUS:8744246270
SN - 1054-6006
VL - 13
SP - 392
EP - 402
JO - Fisheries Oceanography
JF - Fisheries Oceanography
IS - 6
ER -