AMPHIPODS ARE STRONG INTERACTORS IN THE FOOD WEB OF A BROWN-WATER SALMON RIVER
Marine derived biomass from salmon carcasses is incorporated into coastal Pacific Rim salmon river systems via the organisms and structures of the freshwater foodweb. In brown water rivers of Western Kamchatka, the foodweb is dominated by ubiquitous benthic amphipods (Anisogammarus kygi) that consum...
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University of Montana
2007
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ftunivmontana:oai:scholarworks.umt.edu:etd-2328 2023-07-16T03:59:19+02:00 AMPHIPODS ARE STRONG INTERACTORS IN THE FOOD WEB OF A BROWN-WATER SALMON RIVER Thompson, Audrey Marie 2007-01-01T08:00:00Z application/pdf https://scholarworks.umt.edu/etd/1309 https://scholarworks.umt.edu/context/etd/article/2328/viewcontent/01_ThompsonThesis_2007.pdf https://scholarworks.umt.edu/context/etd/article/2328/filename/0/type/additional/viewcontent/UpstreamMigrationAMT.AVI unknown University of Montana https://scholarworks.umt.edu/etd/1309 https://scholarworks.umt.edu/context/etd/article/2328/viewcontent/01_ThompsonThesis_2007.pdf https://scholarworks.umt.edu/context/etd/article/2328/filename/0/type/additional/viewcontent/UpstreamMigrationAMT.AVI ©2007 Audrey Marie Thompson Graduate Student Theses, Dissertations, & Professional Papers amphipod food web marine-derived nutrients Pacific Rim salmon carcass Salmon river thesis 2007 ftunivmontana 2023-06-27T22:40:04Z Marine derived biomass from salmon carcasses is incorporated into coastal Pacific Rim salmon river systems via the organisms and structures of the freshwater foodweb. In brown water rivers of Western Kamchatka, the foodweb is dominated by ubiquitous benthic amphipods (Anisogammarus kygi) that consume salmon carcass material. We hypothesized that A. kygi are a strong interactor in the feedback loop which links dead spawner biomass to juvenile salmonid growth. We found that A. kygi had a complex life cycle with anadromous and resident forms. A. kygi dominated the macro-benthos, comprising more than 88.0% (SE=.01, N=7) of invertebrate biomass, and were highly mobile within the system, exhibiting upstream migrations of ovigerous females (23 ind/m3 ± 5), drift of juveniles, and re-distribution during carcass loading. A. kygi was observed feeding on 97% of salmon carcasses examined (N=100), making up 98.8% (SE .007) of invertebrate consumers, at densities up to 3,000 carcass-1. Amphipods were an important food item for rearing salmonids, especially during the summer when fish diets reached a peak of 88.7% (SE=6.0%) amphipods in 2005, and 68% (SE=18%) amphipods in 2006. The condition factor of salmonid juveniles (K) increased from spring to summer, particularly in juvenile chum, whose spring diet was 76.83% (SE 0.05) amphipods, corroborating the importance of an amphipod based diet for salmonids in this river. We concluded that A .kygi is a strong interactor in the Utkholok system. We also observed abundance of A. kygi in six other brown water rivers of western Kamchatka which suggests that the amphipod-mediated feedback of marine derived nutrients described for the Utkholok, is typical of brown water systems with salmon. Thesis Kamchatka University of Montana: ScholarWorks Pacific Utkholok ENVELOPE(157.206,157.206,57.510,57.510) |
institution |
Open Polar |
collection |
University of Montana: ScholarWorks |
op_collection_id |
ftunivmontana |
language |
unknown |
topic |
amphipod food web marine-derived nutrients Pacific Rim salmon carcass Salmon river |
spellingShingle |
amphipod food web marine-derived nutrients Pacific Rim salmon carcass Salmon river Thompson, Audrey Marie AMPHIPODS ARE STRONG INTERACTORS IN THE FOOD WEB OF A BROWN-WATER SALMON RIVER |
topic_facet |
amphipod food web marine-derived nutrients Pacific Rim salmon carcass Salmon river |
description |
Marine derived biomass from salmon carcasses is incorporated into coastal Pacific Rim salmon river systems via the organisms and structures of the freshwater foodweb. In brown water rivers of Western Kamchatka, the foodweb is dominated by ubiquitous benthic amphipods (Anisogammarus kygi) that consume salmon carcass material. We hypothesized that A. kygi are a strong interactor in the feedback loop which links dead spawner biomass to juvenile salmonid growth. We found that A. kygi had a complex life cycle with anadromous and resident forms. A. kygi dominated the macro-benthos, comprising more than 88.0% (SE=.01, N=7) of invertebrate biomass, and were highly mobile within the system, exhibiting upstream migrations of ovigerous females (23 ind/m3 ± 5), drift of juveniles, and re-distribution during carcass loading. A. kygi was observed feeding on 97% of salmon carcasses examined (N=100), making up 98.8% (SE .007) of invertebrate consumers, at densities up to 3,000 carcass-1. Amphipods were an important food item for rearing salmonids, especially during the summer when fish diets reached a peak of 88.7% (SE=6.0%) amphipods in 2005, and 68% (SE=18%) amphipods in 2006. The condition factor of salmonid juveniles (K) increased from spring to summer, particularly in juvenile chum, whose spring diet was 76.83% (SE 0.05) amphipods, corroborating the importance of an amphipod based diet for salmonids in this river. We concluded that A .kygi is a strong interactor in the Utkholok system. We also observed abundance of A. kygi in six other brown water rivers of western Kamchatka which suggests that the amphipod-mediated feedback of marine derived nutrients described for the Utkholok, is typical of brown water systems with salmon. |
format |
Thesis |
author |
Thompson, Audrey Marie |
author_facet |
Thompson, Audrey Marie |
author_sort |
Thompson, Audrey Marie |
title |
AMPHIPODS ARE STRONG INTERACTORS IN THE FOOD WEB OF A BROWN-WATER SALMON RIVER |
title_short |
AMPHIPODS ARE STRONG INTERACTORS IN THE FOOD WEB OF A BROWN-WATER SALMON RIVER |
title_full |
AMPHIPODS ARE STRONG INTERACTORS IN THE FOOD WEB OF A BROWN-WATER SALMON RIVER |
title_fullStr |
AMPHIPODS ARE STRONG INTERACTORS IN THE FOOD WEB OF A BROWN-WATER SALMON RIVER |
title_full_unstemmed |
AMPHIPODS ARE STRONG INTERACTORS IN THE FOOD WEB OF A BROWN-WATER SALMON RIVER |
title_sort |
amphipods are strong interactors in the food web of a brown-water salmon river |
publisher |
University of Montana |
publishDate |
2007 |
url |
https://scholarworks.umt.edu/etd/1309 https://scholarworks.umt.edu/context/etd/article/2328/viewcontent/01_ThompsonThesis_2007.pdf https://scholarworks.umt.edu/context/etd/article/2328/filename/0/type/additional/viewcontent/UpstreamMigrationAMT.AVI |
long_lat |
ENVELOPE(157.206,157.206,57.510,57.510) |
geographic |
Pacific Utkholok |
geographic_facet |
Pacific Utkholok |
genre |
Kamchatka |
genre_facet |
Kamchatka |
op_source |
Graduate Student Theses, Dissertations, & Professional Papers |
op_relation |
https://scholarworks.umt.edu/etd/1309 https://scholarworks.umt.edu/context/etd/article/2328/viewcontent/01_ThompsonThesis_2007.pdf https://scholarworks.umt.edu/context/etd/article/2328/filename/0/type/additional/viewcontent/UpstreamMigrationAMT.AVI |
op_rights |
©2007 Audrey Marie Thompson |
_version_ |
1771546944051609600 |