Over-wintering diet, growth, and prey available to juvenile coho salmon (Oncorhynchus kisutch) in the West Fork Smith River, Oregon
Over-winter growth of juvenile salmonids may be linked to ocean survival and thus species persistence. Diet, growth, and prey available to juvenile coho, Oncorhynchus kisutch, were examined from December 2004 to April 2005 in four tributaries of the West Fork Smith River (WFSR), Oregon. Juvenile coh...
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Oregon State University
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ftoregonstate:ir.library.oregonstate.edu:nc580r644 2024-04-21T07:58:24+00:00 Over-wintering diet, growth, and prey available to juvenile coho salmon (Oncorhynchus kisutch) in the West Fork Smith River, Oregon Olegario, Anthony Li, Judith L. Skaugset, Arne E. Schoenholtz, Stephen H. Ebersole, Joseph L. Fisheries and Wildlife Oregon State University. Graduate School 429110 bytes application/pdf https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/nc580r644 English [eng] eng unknown Oregon State University https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/nc580r644 All rights reserved Coho salmon -- Oregon -- West Fork Smith River (Douglas County) -- Growth Coho salmon -- Habitat -- Oregon -- West Fork Smith River (Douglas County) Coho salmon -- Food -- Oregon -- West Fork Smith River (Douglas County) Masters Thesis ftoregonstate 2024-03-28T01:59:33Z Over-winter growth of juvenile salmonids may be linked to ocean survival and thus species persistence. Diet, growth, and prey available to juvenile coho, Oncorhynchus kisutch, were examined from December 2004 to April 2005 in four tributaries of the West Fork Smith River (WFSR), Oregon. Juvenile coho growth rate and condition were greatest in spring. Growth rate varied through winter and was highest in Crane Creek, a small intermittent stream (4.3km2 basin area) and lowest in Beaver Creek (7.5 km2), a perennial stream. Prey availability and growth rate decreased in January and February as temperatures dropped, however stomach fullness was highly variable and not correlated to growth rate. The stomach contents of 477 juvenile coho (age-0), were quantitatively examined using an index of relative importance. Juvenile coho fed primarily on benthic invertebrates; rarely consumed non-insectan food included coho fry, salmon eggs, aquatic snails (Juga silicula), salamanders (Dicamptodon tenebrosus), and terrestrial invertebrates. The major portions of their diets, in order of relative importance, were aquatic chironomid larvae (Diptera), baetid mayfly larvae (Ephemeroptera), limnephilid caddisfly larvae (Trichoptera), and winter stonefly larvae (primarily Capniid Stonefly). Similarities in Relatively Important prey distinguished the two intermittent streams from the two perennial streams. In the WFSR tributaries, juvenile coho appear to rely on a variety of food sources to sustain growth and condition during winter. Small intermittent headwater streams may be disproportionately more important to stream fish with greater availability of prey than larger perennial streams highlighting the need to conserve and restore these habitats. Master Thesis Beaver Creek ScholarsArchive@OSU (Oregon State University) |
institution |
Open Polar |
collection |
ScholarsArchive@OSU (Oregon State University) |
op_collection_id |
ftoregonstate |
language |
English unknown |
topic |
Coho salmon -- Oregon -- West Fork Smith River (Douglas County) -- Growth Coho salmon -- Habitat -- Oregon -- West Fork Smith River (Douglas County) Coho salmon -- Food -- Oregon -- West Fork Smith River (Douglas County) |
spellingShingle |
Coho salmon -- Oregon -- West Fork Smith River (Douglas County) -- Growth Coho salmon -- Habitat -- Oregon -- West Fork Smith River (Douglas County) Coho salmon -- Food -- Oregon -- West Fork Smith River (Douglas County) Olegario, Anthony Over-wintering diet, growth, and prey available to juvenile coho salmon (Oncorhynchus kisutch) in the West Fork Smith River, Oregon |
topic_facet |
Coho salmon -- Oregon -- West Fork Smith River (Douglas County) -- Growth Coho salmon -- Habitat -- Oregon -- West Fork Smith River (Douglas County) Coho salmon -- Food -- Oregon -- West Fork Smith River (Douglas County) |
description |
Over-winter growth of juvenile salmonids may be linked to ocean survival and thus species persistence. Diet, growth, and prey available to juvenile coho, Oncorhynchus kisutch, were examined from December 2004 to April 2005 in four tributaries of the West Fork Smith River (WFSR), Oregon. Juvenile coho growth rate and condition were greatest in spring. Growth rate varied through winter and was highest in Crane Creek, a small intermittent stream (4.3km2 basin area) and lowest in Beaver Creek (7.5 km2), a perennial stream. Prey availability and growth rate decreased in January and February as temperatures dropped, however stomach fullness was highly variable and not correlated to growth rate. The stomach contents of 477 juvenile coho (age-0), were quantitatively examined using an index of relative importance. Juvenile coho fed primarily on benthic invertebrates; rarely consumed non-insectan food included coho fry, salmon eggs, aquatic snails (Juga silicula), salamanders (Dicamptodon tenebrosus), and terrestrial invertebrates. The major portions of their diets, in order of relative importance, were aquatic chironomid larvae (Diptera), baetid mayfly larvae (Ephemeroptera), limnephilid caddisfly larvae (Trichoptera), and winter stonefly larvae (primarily Capniid Stonefly). Similarities in Relatively Important prey distinguished the two intermittent streams from the two perennial streams. In the WFSR tributaries, juvenile coho appear to rely on a variety of food sources to sustain growth and condition during winter. Small intermittent headwater streams may be disproportionately more important to stream fish with greater availability of prey than larger perennial streams highlighting the need to conserve and restore these habitats. |
author2 |
Li, Judith L. Skaugset, Arne E. Schoenholtz, Stephen H. Ebersole, Joseph L. Fisheries and Wildlife Oregon State University. Graduate School |
format |
Master Thesis |
author |
Olegario, Anthony |
author_facet |
Olegario, Anthony |
author_sort |
Olegario, Anthony |
title |
Over-wintering diet, growth, and prey available to juvenile coho salmon (Oncorhynchus kisutch) in the West Fork Smith River, Oregon |
title_short |
Over-wintering diet, growth, and prey available to juvenile coho salmon (Oncorhynchus kisutch) in the West Fork Smith River, Oregon |
title_full |
Over-wintering diet, growth, and prey available to juvenile coho salmon (Oncorhynchus kisutch) in the West Fork Smith River, Oregon |
title_fullStr |
Over-wintering diet, growth, and prey available to juvenile coho salmon (Oncorhynchus kisutch) in the West Fork Smith River, Oregon |
title_full_unstemmed |
Over-wintering diet, growth, and prey available to juvenile coho salmon (Oncorhynchus kisutch) in the West Fork Smith River, Oregon |
title_sort |
over-wintering diet, growth, and prey available to juvenile coho salmon (oncorhynchus kisutch) in the west fork smith river, oregon |
publisher |
Oregon State University |
url |
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/nc580r644 |
genre |
Beaver Creek |
genre_facet |
Beaver Creek |
op_relation |
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/nc580r644 |
op_rights |
All rights reserved |
_version_ |
1796939568931405824 |