Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula
Although crabeater seals Lobodon carcinophaga are among the most abundant consumers of Antarctic krill Euphausia superba, their diet has rarely been studied throughout most of the species’ range. Using 8 13C and 8 15N values in vibrissae from 53 seals, we examined the trophic ecology of crabeater se...
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ftcalifstateuniv:oai:scholarworks:765372006 2024-09-30T14:24:44+00:00 Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula L. A. Hückstädt J. M. Burns P. L. Koch B. I. McDonald Daniel E. Crocker D. P. Costa 2012-05-30 http://hdl.handle.net/10211.3/121205 English eng Marine Ecology Progress Series This research was supported by the National Science Foundation through the Office of Polar Programs (grants ANT- 0440687, 0840375, 0523332, and 0838937), National Undersea Research Program, National Oceanographic Partnership Program through the Office of Naval Research, and the Marine Mammal Commission. L.A.H. was supported by CONICYT-Fulbright (Chile). B.I.M. was supported by a NSF predoctoral fellowship and EPA STAR fellowship. http://hdl.handle.net/10211.3/121205 Antarctic fish stable isotopes Lobodon carcinophaga Euphausia superba diet specialization Article 2012 ftcalifstateuniv 2024-09-10T17:06:15Z Although crabeater seals Lobodon carcinophaga are among the most abundant consumers of Antarctic krill Euphausia superba, their diet has rarely been studied throughout most of the species’ range. Using 8 13C and 8 15N values in vibrissae from 53 seals, we examined the trophic ecology of crabeater seals from the western Antarctic Peninsula (wAP) in 2001, 2002 and 2007. We observed a wide variability in individual seal mean 8 13C values, which ranged from −19.8‰ to −24.9‰ , whereas mean 8 15N value varied from 5.4‰ to 7.9‰. We identified a positive significant effect of seal mass on 8 13C values, as well as a significant seasonal effect (higher 8 13C values in austral winter), which likely resulted from changes in the composition of the community of primary producers. 8 15N values for crabeater seals, on the other hand, were affected by year, with individuals in 2002 having higher 8 15N values. The median (with range) contribution of Antarctic krill to the diet of crabeater seals, as estimated using the Bayesian mixing model MixSIR, was 87.9% (81.2 to 94.8%). During 2002, krill biomass in the wAP was at one of its lowest levels during the last 2 decades, coinciding with a slight reduction in the importance of krill for the diet of the seals that year, which reached 84.5% (75.1 to 92.4%). Despite the relative plasticity observed in the diet of crabeater seals, it is unknown to what extent, and at what rate, crabeater seals might be able to switch to a more generalized diet, which might impact their fitness, given the ongoing environmental change along the wAP. Published by and copyright of Marine Ecology Progress Series. The definitive version of this article is available at: http://www.int-res.com/articles/meps2012/455/m455p287.pdf Huctstadt, L.A., Burns, J.M., Koch, P.L., McDonald, B.I., Crocker, Daniel E., Costa, D.P. "Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula." Marine Ecology Progress Series 455 (2012): 287-301. 1616-1599 Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Antarctic Peninsula Crabeater Seal Crabeater Seals Euphausia superba Scholarworks from California State University Antarctic Antarctic Peninsula Austral |
institution |
Open Polar |
collection |
Scholarworks from California State University |
op_collection_id |
ftcalifstateuniv |
language |
English |
topic |
Antarctic fish stable isotopes Lobodon carcinophaga Euphausia superba diet specialization |
spellingShingle |
Antarctic fish stable isotopes Lobodon carcinophaga Euphausia superba diet specialization L. A. Hückstädt J. M. Burns P. L. Koch B. I. McDonald Daniel E. Crocker D. P. Costa Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula |
topic_facet |
Antarctic fish stable isotopes Lobodon carcinophaga Euphausia superba diet specialization |
description |
Although crabeater seals Lobodon carcinophaga are among the most abundant consumers of Antarctic krill Euphausia superba, their diet has rarely been studied throughout most of the species’ range. Using 8 13C and 8 15N values in vibrissae from 53 seals, we examined the trophic ecology of crabeater seals from the western Antarctic Peninsula (wAP) in 2001, 2002 and 2007. We observed a wide variability in individual seal mean 8 13C values, which ranged from −19.8‰ to −24.9‰ , whereas mean 8 15N value varied from 5.4‰ to 7.9‰. We identified a positive significant effect of seal mass on 8 13C values, as well as a significant seasonal effect (higher 8 13C values in austral winter), which likely resulted from changes in the composition of the community of primary producers. 8 15N values for crabeater seals, on the other hand, were affected by year, with individuals in 2002 having higher 8 15N values. The median (with range) contribution of Antarctic krill to the diet of crabeater seals, as estimated using the Bayesian mixing model MixSIR, was 87.9% (81.2 to 94.8%). During 2002, krill biomass in the wAP was at one of its lowest levels during the last 2 decades, coinciding with a slight reduction in the importance of krill for the diet of the seals that year, which reached 84.5% (75.1 to 92.4%). Despite the relative plasticity observed in the diet of crabeater seals, it is unknown to what extent, and at what rate, crabeater seals might be able to switch to a more generalized diet, which might impact their fitness, given the ongoing environmental change along the wAP. Published by and copyright of Marine Ecology Progress Series. The definitive version of this article is available at: http://www.int-res.com/articles/meps2012/455/m455p287.pdf Huctstadt, L.A., Burns, J.M., Koch, P.L., McDonald, B.I., Crocker, Daniel E., Costa, D.P. "Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula." Marine Ecology Progress Series 455 (2012): 287-301. 1616-1599 |
format |
Article in Journal/Newspaper |
author |
L. A. Hückstädt J. M. Burns P. L. Koch B. I. McDonald Daniel E. Crocker D. P. Costa |
author_facet |
L. A. Hückstädt J. M. Burns P. L. Koch B. I. McDonald Daniel E. Crocker D. P. Costa |
author_sort |
L. A. Hückstädt |
title |
Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula |
title_short |
Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula |
title_full |
Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula |
title_fullStr |
Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula |
title_full_unstemmed |
Diet of a Specialist in a Changing Environment: The Crabeater Seal Along the Western Antarctic Peninsula |
title_sort |
diet of a specialist in a changing environment: the crabeater seal along the western antarctic peninsula |
publisher |
Marine Ecology Progress Series |
publishDate |
2012 |
url |
http://hdl.handle.net/10211.3/121205 |
geographic |
Antarctic Antarctic Peninsula Austral |
geographic_facet |
Antarctic Antarctic Peninsula Austral |
genre |
Antarc* Antarctic Antarctic Krill Antarctic Peninsula Crabeater Seal Crabeater Seals Euphausia superba |
genre_facet |
Antarc* Antarctic Antarctic Krill Antarctic Peninsula Crabeater Seal Crabeater Seals Euphausia superba |
op_relation |
http://hdl.handle.net/10211.3/121205 |
_version_ |
1811642091200053248 |