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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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 |
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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 |
_version_ |
1768388286074585088 |