Evaluation of prey composition and nutritional value of diets of free-ranging harbor seals (Phoca vitulina) from Tugidak Island
Thesis (M.S.) University of Alaska Fairbanks, 2012 Changes in climate can cause shifts in ecosystem structure that can affect quantity or quality of prey available to predator populations. Due to sex or age-specific behaviors of predators, certain classes within a population may be more severely imp...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/11316 2023-05-15T16:33:03+02:00 Evaluation of prey composition and nutritional value of diets of free-ranging harbor seals (Phoca vitulina) from Tugidak Island Geiger, Gretchen L. Atkinson, Shannon Carpenter, James Horstmann-Dehn, Larissa Wynne, Kate 2012-12 http://hdl.handle.net/11122/11316 en_US eng http://hdl.handle.net/11122/11316 Marin Science and Limnology Program harbor seal diet nutrition Alaska Tugidak Island Thesis ms 2012 ftunivalaska 2023-02-23T21:37:40Z Thesis (M.S.) University of Alaska Fairbanks, 2012 Changes in climate can cause shifts in ecosystem structure that can affect quantity or quality of prey available to predator populations. Due to sex or age-specific behaviors of predators, certain classes within a population may be more severely impacted by changes in their diet. This study evaluated prey composition and nutritional value of summer diets of harbor seals (Phoca vitulina richardii) from Tugidak Island, Alaska from 2001-2009. The MIXIT-WIN program was used to estimate the nutritional value of average harbor seal diets. Changes in relative abundance of certain prey species were correlated to sea surface temperature anomalies. Despite changes in prey composition, the nutritional value of the average harbor seal diet did not change. Fecal corticosteroid metabolite profiles were analyzed to identify age and sex of individual harbor seals from scats. Profiles obtained from a known adult male harbor seal could be differentiated from those of known adult female and juvenile male seals. Similar profiles were observed in unknown age and sex samples. Even though diet diversity differed between these groups, the nutritional quality of consumed diets was not significantly different. Tugidak Island harbor seals have flexible diets allowing them to capitalize on available prey to maintain their nutritional intake. Pollock Conservation Cooperative Research Center (to SA and GLG), Alaska Department of Fish and Game (to GMB), and National Marine Fisheries Service (to KW) Thesis harbor seal Phoca vitulina Alaska University of Alaska: ScholarWorks@UA Fairbanks Island Harbor ENVELOPE(70.067,70.067,-49.483,-49.483) |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
harbor seal diet nutrition Alaska Tugidak Island |
spellingShingle |
harbor seal diet nutrition Alaska Tugidak Island Geiger, Gretchen L. Evaluation of prey composition and nutritional value of diets of free-ranging harbor seals (Phoca vitulina) from Tugidak Island |
topic_facet |
harbor seal diet nutrition Alaska Tugidak Island |
description |
Thesis (M.S.) University of Alaska Fairbanks, 2012 Changes in climate can cause shifts in ecosystem structure that can affect quantity or quality of prey available to predator populations. Due to sex or age-specific behaviors of predators, certain classes within a population may be more severely impacted by changes in their diet. This study evaluated prey composition and nutritional value of summer diets of harbor seals (Phoca vitulina richardii) from Tugidak Island, Alaska from 2001-2009. The MIXIT-WIN program was used to estimate the nutritional value of average harbor seal diets. Changes in relative abundance of certain prey species were correlated to sea surface temperature anomalies. Despite changes in prey composition, the nutritional value of the average harbor seal diet did not change. Fecal corticosteroid metabolite profiles were analyzed to identify age and sex of individual harbor seals from scats. Profiles obtained from a known adult male harbor seal could be differentiated from those of known adult female and juvenile male seals. Similar profiles were observed in unknown age and sex samples. Even though diet diversity differed between these groups, the nutritional quality of consumed diets was not significantly different. Tugidak Island harbor seals have flexible diets allowing them to capitalize on available prey to maintain their nutritional intake. Pollock Conservation Cooperative Research Center (to SA and GLG), Alaska Department of Fish and Game (to GMB), and National Marine Fisheries Service (to KW) |
author2 |
Atkinson, Shannon Carpenter, James Horstmann-Dehn, Larissa Wynne, Kate |
format |
Thesis |
author |
Geiger, Gretchen L. |
author_facet |
Geiger, Gretchen L. |
author_sort |
Geiger, Gretchen L. |
title |
Evaluation of prey composition and nutritional value of diets of free-ranging harbor seals (Phoca vitulina) from Tugidak Island |
title_short |
Evaluation of prey composition and nutritional value of diets of free-ranging harbor seals (Phoca vitulina) from Tugidak Island |
title_full |
Evaluation of prey composition and nutritional value of diets of free-ranging harbor seals (Phoca vitulina) from Tugidak Island |
title_fullStr |
Evaluation of prey composition and nutritional value of diets of free-ranging harbor seals (Phoca vitulina) from Tugidak Island |
title_full_unstemmed |
Evaluation of prey composition and nutritional value of diets of free-ranging harbor seals (Phoca vitulina) from Tugidak Island |
title_sort |
evaluation of prey composition and nutritional value of diets of free-ranging harbor seals (phoca vitulina) from tugidak island |
publishDate |
2012 |
url |
http://hdl.handle.net/11122/11316 |
long_lat |
ENVELOPE(70.067,70.067,-49.483,-49.483) |
geographic |
Fairbanks Island Harbor |
geographic_facet |
Fairbanks Island Harbor |
genre |
harbor seal Phoca vitulina Alaska |
genre_facet |
harbor seal Phoca vitulina Alaska |
op_relation |
http://hdl.handle.net/11122/11316 Marin Science and Limnology Program |
_version_ |
1766022771882590208 |