Elephant seal foraging success is enhanced in Antarctic coastal polynyas
Antarctic polynyas are persistent open water areas which enable early and large seasonal phytoplankton blooms. This high primary productivity, boosted by iron supply from coastal glaciers, attracts organisms from all trophic levels to form a rich and diverse community. How the ecological benefit of...
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Published in | Proceedings of the Royal Society. B, Biological sciences Vol. 289; no. 1967; p. 20212452 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Royal Society, The
26.01.2022
The Royal Society |
Subjects | |
Online Access | Get full text |
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Summary: | Antarctic polynyas are persistent open water areas which enable early and large seasonal phytoplankton blooms. This high primary productivity, boosted by iron supply from coastal glaciers, attracts organisms from all trophic levels to form a rich and diverse community. How the ecological benefit of polynya productivity is translated to the highest trophic levels remains poorly resolved. We studied 119 southern elephant seals feeding over the Antarctic shelf and demonstrated that: (i) 96% of seals foraging here used polynyas, with individuals spending on average 62% of their time there; (ii) the seals exhibited more area-restricted search behaviour when in polynyas; and (iii) these seals gained more energy (indicated by increased buoyancy from greater fat stores) when inside polynyas. This higher-quality foraging existed even when ice was not present in the study area, indicating that these are important and predictable foraging grounds year-round. Despite these energetic advantages from using polynyas, not all the seals used them extensively. Factors other than food supply may influence an individual's choice in their use of feeding grounds, such as exposure to predation or the probability of being able to return to distant sub-Antarctic breeding sites. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 PMCID: PMC8790345 Electronic supplementary material is available online at https://doi.org/10.6084/m9.figshare.c.5758763. |
ISSN: | 0962-8452 1471-2954 |
DOI: | 10.1098/rspb.2021.2452 |