Growth rates of Antarctic fur seals as indices of environmental conditions
The growth rates of Antarctic fur seal (Arctocephalus gazella) pups estimated from weighing cross-sections of the population were compared with measured/ inferred changes in the availability of their main prey species, Antarctic krill (Euphausia superba) from 1989 to 2000. There was no relationship...
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Online Access: | http://nora.nerc.ac.uk/id/eprint/17393/ http://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.2002.tb01049.x/abstract |
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ftnerc:oai:nora.nerc.ac.uk:17393 2023-05-15T13:45:12+02:00 Growth rates of Antarctic fur seals as indices of environmental conditions Reid, Keith 2002 http://nora.nerc.ac.uk/id/eprint/17393/ http://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.2002.tb01049.x/abstract unknown Wiley Reid, Keith. 2002 Growth rates of Antarctic fur seals as indices of environmental conditions. Marine Mammal Science, 18 (2). 469-482. https://doi.org/10.1111/j.1748-7692.2002.tb01049.x <https://doi.org/10.1111/j.1748-7692.2002.tb01049.x> Publication - Article PeerReviewed 2002 ftnerc https://doi.org/10.1111/j.1748-7692.2002.tb01049.x 2023-02-04T19:31:05Z The growth rates of Antarctic fur seal (Arctocephalus gazella) pups estimated from weighing cross-sections of the population were compared with measured/ inferred changes in the availability of their main prey species, Antarctic krill (Euphausia superba) from 1989 to 2000. There was no relationship between growth rate and mass at weaning and there were counter-intuitive indications of higher growth rates in years of low krill availability. Biases reflecting changes in the component of the population available for sampling appear to invalidate the widely held assumption that interannual differences in growth rate can reliably be derived from differences in the slope of a linear relationship based on cross-sectional population samples. A new index was developed, based on the deviation of pup mass at age in each year compared to the multiyear mean, that was not dependent on assumptions of linearity. The indices of growth deviates produced a more logical relationship with other indices of pup development and related more appropriately to variations in prey availability. The potential impact of methodological biases on the interpretation of growth rate suggests that comparisons of growth rates should not rely on assumptions regarding the underlying growth pattern. Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seal Antarctic Fur Seals Antarctic Krill Arctocephalus gazella Euphausia superba Natural Environment Research Council: NERC Open Research Archive Antarctic Marine Mammal Science 18 2 469 482 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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unknown |
description |
The growth rates of Antarctic fur seal (Arctocephalus gazella) pups estimated from weighing cross-sections of the population were compared with measured/ inferred changes in the availability of their main prey species, Antarctic krill (Euphausia superba) from 1989 to 2000. There was no relationship between growth rate and mass at weaning and there were counter-intuitive indications of higher growth rates in years of low krill availability. Biases reflecting changes in the component of the population available for sampling appear to invalidate the widely held assumption that interannual differences in growth rate can reliably be derived from differences in the slope of a linear relationship based on cross-sectional population samples. A new index was developed, based on the deviation of pup mass at age in each year compared to the multiyear mean, that was not dependent on assumptions of linearity. The indices of growth deviates produced a more logical relationship with other indices of pup development and related more appropriately to variations in prey availability. The potential impact of methodological biases on the interpretation of growth rate suggests that comparisons of growth rates should not rely on assumptions regarding the underlying growth pattern. |
format |
Article in Journal/Newspaper |
author |
Reid, Keith |
spellingShingle |
Reid, Keith Growth rates of Antarctic fur seals as indices of environmental conditions |
author_facet |
Reid, Keith |
author_sort |
Reid, Keith |
title |
Growth rates of Antarctic fur seals as indices of environmental conditions |
title_short |
Growth rates of Antarctic fur seals as indices of environmental conditions |
title_full |
Growth rates of Antarctic fur seals as indices of environmental conditions |
title_fullStr |
Growth rates of Antarctic fur seals as indices of environmental conditions |
title_full_unstemmed |
Growth rates of Antarctic fur seals as indices of environmental conditions |
title_sort |
growth rates of antarctic fur seals as indices of environmental conditions |
publisher |
Wiley |
publishDate |
2002 |
url |
http://nora.nerc.ac.uk/id/eprint/17393/ http://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.2002.tb01049.x/abstract |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctic Fur Seal Antarctic Fur Seals Antarctic Krill Arctocephalus gazella Euphausia superba |
genre_facet |
Antarc* Antarctic Antarctic Fur Seal Antarctic Fur Seals Antarctic Krill Arctocephalus gazella Euphausia superba |
op_relation |
Reid, Keith. 2002 Growth rates of Antarctic fur seals as indices of environmental conditions. Marine Mammal Science, 18 (2). 469-482. https://doi.org/10.1111/j.1748-7692.2002.tb01049.x <https://doi.org/10.1111/j.1748-7692.2002.tb01049.x> |
op_doi |
https://doi.org/10.1111/j.1748-7692.2002.tb01049.x |
container_title |
Marine Mammal Science |
container_volume |
18 |
container_issue |
2 |
container_start_page |
469 |
op_container_end_page |
482 |
_version_ |
1766216290231386112 |