Biomass and energy consumption of the south Georgia population of southern elephant seals
The total annual energy expenditure was estimated for different age and sex classes of southern elephant seals, Mirounga leonina , that breed at South Georgia. The estimated energy costs of reproduction, growth, foraging, and molt were used to calculate an annual energy budget for individuals in eac...
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University of California Press
2022
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Online Access: | https://research-portal.st-andrews.ac.uk/en/researchoutput/biomass-and-energy-consumption-of-the-south-georgia-population-of-southern-elephant-seals(b31583a5-08bb-43e9-8123-f91b032ef3af).html https://doi.org/10.1525/9780520328150-008 https://doi.org/10.1525/9780520328150 https://discover.libraryhub.jisc.ac.uk/search?isn=9780520328150&rn=1 |
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ftunstandrewcris:oai:research-portal.st-andrews.ac.uk:publications/b31583a5-08bb-43e9-8123-f91b032ef3af 2024-06-23T07:52:29+00:00 Biomass and energy consumption of the south Georgia population of southern elephant seals Boyd, Ian L. Ambom, Tom A. Fedak, Michael A. Le Beouf, Burney J. Laws, Richard M. 2022-07-01 https://research-portal.st-andrews.ac.uk/en/researchoutput/biomass-and-energy-consumption-of-the-south-georgia-population-of-southern-elephant-seals(b31583a5-08bb-43e9-8123-f91b032ef3af).html https://doi.org/10.1525/9780520328150-008 https://doi.org/10.1525/9780520328150 https://discover.libraryhub.jisc.ac.uk/search?isn=9780520328150&rn=1 eng eng University of California Press https://research-portal.st-andrews.ac.uk/en/researchoutput/biomass-and-energy-consumption-of-the-south-georgia-population-of-southern-elephant-seals(b31583a5-08bb-43e9-8123-f91b032ef3af).html urn:ISBN:9780520368170 urn:ISBN:9780520328143 info:eu-repo/semantics/restrictedAccess Boyd , I L , Ambom , T A & Fedak , M A 2022 , Biomass and energy consumption of the south Georgia population of southern elephant seals . in B J Le Beouf & R M Laws (eds) , Elephant seals : population ecology, behavior, and physiology . University of California Press , Berkeley, CA , pp. 98-117 . https://doi.org/10.1525/9780520328150-008 bookPart 2022 ftunstandrewcris https://doi.org/10.1525/9780520328150-00810.1525/9780520328150 2024-05-29T23:42:32Z The total annual energy expenditure was estimated for different age and sex classes of southern elephant seals, Mirounga leonina , that breed at South Georgia. The estimated energy costs of reproduction, growth, foraging, and molt were used to calculate an annual energy budget for individuals in each age and sex class. This was combined with population size and age structure to estimate population energy requirements. The estimated average metabolic cost of maintenance for adult males and females was 0.17 and 0.39 MJ/year, respectively. Male biomass accounted for 63% of the total population biomass (222,903 metric tonnes), and the metabolic power for the whole population averaged over one year was 190 MWatts. Total energy expenditure of each age class declined during the first two years but then began to increase because of the onset of reproduction in females and because of increased energy costs of foraging and growth in males. Foraging accounted for 63.2% and 68.2% of the annual energy budget in males and females, respectively. The total annual energy expenditure was 6.01 X 109 MJ/year, and 59% of this was accounted for by males. The gross energy requirement was 7.89 X 109 MJ/year. The production efficiency was 8.2% Average daily gross energy intake during potential foraging periods was 77.3 and 43.2 MJ/day for males and females, respectively. This suggested a capture rate of 0.26 and 0.15 kg of fish or muscular squid per dive for males and females, respectively. Biomass of food consumed depended on assumptions about diet composition. If southern elephant seals at South Georgia fed exclusively on squid, the consumption biomass was 2.28 X 10 6 tonnes/year. Book Part Elephant Seals Mirounga leonina Southern Elephant Seals University of St Andrews: Research Portal |
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Open Polar |
collection |
University of St Andrews: Research Portal |
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ftunstandrewcris |
language |
English |
description |
The total annual energy expenditure was estimated for different age and sex classes of southern elephant seals, Mirounga leonina , that breed at South Georgia. The estimated energy costs of reproduction, growth, foraging, and molt were used to calculate an annual energy budget for individuals in each age and sex class. This was combined with population size and age structure to estimate population energy requirements. The estimated average metabolic cost of maintenance for adult males and females was 0.17 and 0.39 MJ/year, respectively. Male biomass accounted for 63% of the total population biomass (222,903 metric tonnes), and the metabolic power for the whole population averaged over one year was 190 MWatts. Total energy expenditure of each age class declined during the first two years but then began to increase because of the onset of reproduction in females and because of increased energy costs of foraging and growth in males. Foraging accounted for 63.2% and 68.2% of the annual energy budget in males and females, respectively. The total annual energy expenditure was 6.01 X 109 MJ/year, and 59% of this was accounted for by males. The gross energy requirement was 7.89 X 109 MJ/year. The production efficiency was 8.2% Average daily gross energy intake during potential foraging periods was 77.3 and 43.2 MJ/day for males and females, respectively. This suggested a capture rate of 0.26 and 0.15 kg of fish or muscular squid per dive for males and females, respectively. Biomass of food consumed depended on assumptions about diet composition. If southern elephant seals at South Georgia fed exclusively on squid, the consumption biomass was 2.28 X 10 6 tonnes/year. |
author2 |
Le Beouf, Burney J. Laws, Richard M. |
format |
Book Part |
author |
Boyd, Ian L. Ambom, Tom A. Fedak, Michael A. |
spellingShingle |
Boyd, Ian L. Ambom, Tom A. Fedak, Michael A. Biomass and energy consumption of the south Georgia population of southern elephant seals |
author_facet |
Boyd, Ian L. Ambom, Tom A. Fedak, Michael A. |
author_sort |
Boyd, Ian L. |
title |
Biomass and energy consumption of the south Georgia population of southern elephant seals |
title_short |
Biomass and energy consumption of the south Georgia population of southern elephant seals |
title_full |
Biomass and energy consumption of the south Georgia population of southern elephant seals |
title_fullStr |
Biomass and energy consumption of the south Georgia population of southern elephant seals |
title_full_unstemmed |
Biomass and energy consumption of the south Georgia population of southern elephant seals |
title_sort |
biomass and energy consumption of the south georgia population of southern elephant seals |
publisher |
University of California Press |
publishDate |
2022 |
url |
https://research-portal.st-andrews.ac.uk/en/researchoutput/biomass-and-energy-consumption-of-the-south-georgia-population-of-southern-elephant-seals(b31583a5-08bb-43e9-8123-f91b032ef3af).html https://doi.org/10.1525/9780520328150-008 https://doi.org/10.1525/9780520328150 https://discover.libraryhub.jisc.ac.uk/search?isn=9780520328150&rn=1 |
genre |
Elephant Seals Mirounga leonina Southern Elephant Seals |
genre_facet |
Elephant Seals Mirounga leonina Southern Elephant Seals |
op_source |
Boyd , I L , Ambom , T A & Fedak , M A 2022 , Biomass and energy consumption of the south Georgia population of southern elephant seals . in B J Le Beouf & R M Laws (eds) , Elephant seals : population ecology, behavior, and physiology . University of California Press , Berkeley, CA , pp. 98-117 . https://doi.org/10.1525/9780520328150-008 |
op_relation |
https://research-portal.st-andrews.ac.uk/en/researchoutput/biomass-and-energy-consumption-of-the-south-georgia-population-of-southern-elephant-seals(b31583a5-08bb-43e9-8123-f91b032ef3af).html urn:ISBN:9780520368170 urn:ISBN:9780520328143 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1525/9780520328150-00810.1525/9780520328150 |
_version_ |
1802643795864453120 |