Assessing The Health Of Harbor Seals In Alaska

Dissertation (Ph.D.) University of Alaska Fairbanks, 2003 Declining populations of pinnipeds in the Gulf of Alaska, possibly resulting from changes in prey quality, prompted research to determine the population health status of harbor seals (Phoca vitulina) using blood chemistry and digestive constr...

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Bibliographic Details
Main Author: Trumble, Stephen John
Other Authors: Castellini, Michael
Format: Doctoral or Postdoctoral Thesis
Language:unknown
Published: 2003
Subjects:
Online Access:http://hdl.handle.net/11122/8669
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spelling ftunivalaska:oai:scholarworks.alaska.edu:11122/8669 2023-06-11T04:12:25+02:00 Assessing The Health Of Harbor Seals In Alaska Trumble, Stephen John Castellini, Michael 2003 http://hdl.handle.net/11122/8669 unknown http://hdl.handle.net/11122/8669 Animal Physiology Ecology Zoology Harbor seal Health Alaska Metabolism Food Dissertation phd 2003 ftunivalaska 2023-05-11T17:54:52Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2003 Declining populations of pinnipeds in the Gulf of Alaska, possibly resulting from changes in prey quality, prompted research to determine the population health status of harbor seals (Phoca vitulina) using blood chemistry and digestive constraints. Blood chemistry and morphology reference range values between two harbor seal pup populations in Alaska, one population in continued decline, Prince William Sound, and another in recent increase, Tugidak Island, offered clues that blood values can vary on the population scale and that health assessment must utilize an appropriate set of reference values for valid comparisons. Subsequently, a captive study involving harbor seals yielded changes in ten blood chemistry or hematology values as a function of season and diet. These data provided evidence that populations may have distinct "identities" based on blood chemistry values. The "metabolic identity" of a population provides evidence of the relationship between environmental stressors and the genetic capacity of the animal to respond to metabolic demands. This made it possible to better understand population level differentiation in plasma chemistry values and thus assess the health of animals occupying the outlier regions of populations, since these regions are often suggestive of poor health. A captive study involving harbor seals, which are known to consume the low quality prey (pollock) implicated in the declines of many species of birds and mammals in the Gulf of Alaska, yielded consistent dry matter digestibility resulting in greater gut fill from pollock than from herring. Digestible energy intakes from pollock were greater than from either herring or the mixed diet. Lipid digestibility of herring declined from 90% to 50% when lipid intake exceeded 60 g kg -0.75 d-1. Results of this study imply that a flexible digestive system for harbor seals can compensate for ingesting a prey of low energy density by increasing gut fill and enhancing protein and ... Doctoral or Postdoctoral Thesis harbor seal Phoca vitulina Alaska University of Alaska: ScholarWorks@UA Fairbanks Gulf of Alaska
institution Open Polar
collection University of Alaska: ScholarWorks@UA
op_collection_id ftunivalaska
language unknown
topic Animal Physiology
Ecology
Zoology
Harbor seal
Health
Alaska
Metabolism
Food
spellingShingle Animal Physiology
Ecology
Zoology
Harbor seal
Health
Alaska
Metabolism
Food
Trumble, Stephen John
Assessing The Health Of Harbor Seals In Alaska
topic_facet Animal Physiology
Ecology
Zoology
Harbor seal
Health
Alaska
Metabolism
Food
description Dissertation (Ph.D.) University of Alaska Fairbanks, 2003 Declining populations of pinnipeds in the Gulf of Alaska, possibly resulting from changes in prey quality, prompted research to determine the population health status of harbor seals (Phoca vitulina) using blood chemistry and digestive constraints. Blood chemistry and morphology reference range values between two harbor seal pup populations in Alaska, one population in continued decline, Prince William Sound, and another in recent increase, Tugidak Island, offered clues that blood values can vary on the population scale and that health assessment must utilize an appropriate set of reference values for valid comparisons. Subsequently, a captive study involving harbor seals yielded changes in ten blood chemistry or hematology values as a function of season and diet. These data provided evidence that populations may have distinct "identities" based on blood chemistry values. The "metabolic identity" of a population provides evidence of the relationship between environmental stressors and the genetic capacity of the animal to respond to metabolic demands. This made it possible to better understand population level differentiation in plasma chemistry values and thus assess the health of animals occupying the outlier regions of populations, since these regions are often suggestive of poor health. A captive study involving harbor seals, which are known to consume the low quality prey (pollock) implicated in the declines of many species of birds and mammals in the Gulf of Alaska, yielded consistent dry matter digestibility resulting in greater gut fill from pollock than from herring. Digestible energy intakes from pollock were greater than from either herring or the mixed diet. Lipid digestibility of herring declined from 90% to 50% when lipid intake exceeded 60 g kg -0.75 d-1. Results of this study imply that a flexible digestive system for harbor seals can compensate for ingesting a prey of low energy density by increasing gut fill and enhancing protein and ...
author2 Castellini, Michael
format Doctoral or Postdoctoral Thesis
author Trumble, Stephen John
author_facet Trumble, Stephen John
author_sort Trumble, Stephen John
title Assessing The Health Of Harbor Seals In Alaska
title_short Assessing The Health Of Harbor Seals In Alaska
title_full Assessing The Health Of Harbor Seals In Alaska
title_fullStr Assessing The Health Of Harbor Seals In Alaska
title_full_unstemmed Assessing The Health Of Harbor Seals In Alaska
title_sort assessing the health of harbor seals in alaska
publishDate 2003
url http://hdl.handle.net/11122/8669
geographic Fairbanks
Gulf of Alaska
geographic_facet Fairbanks
Gulf of Alaska
genre harbor seal
Phoca vitulina
Alaska
genre_facet harbor seal
Phoca vitulina
Alaska
op_relation http://hdl.handle.net/11122/8669
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