Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea
Seasonal sea-ice cover has been decreasing in the southeastern Bering Sea shelf, which might affect ecosystem dynamics and availability of food resources to marine top predators breeding in the region. In this study, we investigated the foraging responses of two seabird species, surface-foraging red...
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Online Access: | https://doi.org/10.5194/bg-13-2405-2016 https://doaj.org/article/cdfa0ca06a584ea18ce87f5a1f9ebe29 |
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ftdoajarticles:oai:doaj.org/article:cdfa0ca06a584ea18ce87f5a1f9ebe29 2023-05-15T15:43:30+02:00 Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea T. Yamamoto N. Kokubun D. M. Kikuchi N. Sato A. Takahashi A. P. Will A. S. Kitaysky Y. Watanuki 2016-04-01T00:00:00Z https://doi.org/10.5194/bg-13-2405-2016 https://doaj.org/article/cdfa0ca06a584ea18ce87f5a1f9ebe29 EN eng Copernicus Publications http://www.biogeosciences.net/13/2405/2016/bg-13-2405-2016.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-13-2405-2016 https://doaj.org/article/cdfa0ca06a584ea18ce87f5a1f9ebe29 Biogeosciences, Vol 13, Iss 8, Pp 2405-2414 (2016) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2016 ftdoajarticles https://doi.org/10.5194/bg-13-2405-2016 2022-12-31T11:37:14Z Seasonal sea-ice cover has been decreasing in the southeastern Bering Sea shelf, which might affect ecosystem dynamics and availability of food resources to marine top predators breeding in the region. In this study, we investigated the foraging responses of two seabird species, surface-foraging red-legged kittiwakes Rissa brevirostris (hereafter, RLKI) and pursuit-diving foraging thick-billed murres Uria lomvia (TBMU) to different marine environmental conditions over 2 years. At-sea distributions of RLKI and TBMU breeding on St. George Island, the largest seabird colony in the region, were recorded using GPS loggers, and blood samples were taken to examine their physiological condition and isotopic foraging niche in a given year. Between the study years, winter ice retreated earlier and summer water temperatures were relatively warmer in 2014 compared to those in 2013. RLKI foraging occurred mostly over the oceanic basin in both years. TBMU, however, foraged mostly over the shelf but showed a relatively higher use of the shelf break and oceanic basin in 2013. The foraging distances from the colony peaked at 250–300 km in 2013 and bimodally at 150–250 and 300–350 km in 2014 for RLKI and tended to be farther in 2013 compared to those in 2014 for TBMU. Plasma levels of corticosterone did not differ between the years in RLKI but differed in TBMU, showing higher levels of physiological stress incurred by murres in 2013, the year of relatively cooler sea surface temperatures with later sea-ice retreat. δ 13 N (a proxy of trophic level of prey) did not differ between the years in either RLKI or TBMU. These results suggest that the response of ecosystem dynamics to climate variability in the southeastern Bering Sea may differ between the ocean basin and continental shelf regions, which, in turn, may generate differential responses in seabirds relying on those habitats for foraging. Article in Journal/Newspaper Bering Sea Sea ice Uria lomvia uria Directory of Open Access Journals: DOAJ Articles Bering Sea Biogeosciences 13 8 2405 2414 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 T. Yamamoto N. Kokubun D. M. Kikuchi N. Sato A. Takahashi A. P. Will A. S. Kitaysky Y. Watanuki Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Seasonal sea-ice cover has been decreasing in the southeastern Bering Sea shelf, which might affect ecosystem dynamics and availability of food resources to marine top predators breeding in the region. In this study, we investigated the foraging responses of two seabird species, surface-foraging red-legged kittiwakes Rissa brevirostris (hereafter, RLKI) and pursuit-diving foraging thick-billed murres Uria lomvia (TBMU) to different marine environmental conditions over 2 years. At-sea distributions of RLKI and TBMU breeding on St. George Island, the largest seabird colony in the region, were recorded using GPS loggers, and blood samples were taken to examine their physiological condition and isotopic foraging niche in a given year. Between the study years, winter ice retreated earlier and summer water temperatures were relatively warmer in 2014 compared to those in 2013. RLKI foraging occurred mostly over the oceanic basin in both years. TBMU, however, foraged mostly over the shelf but showed a relatively higher use of the shelf break and oceanic basin in 2013. The foraging distances from the colony peaked at 250–300 km in 2013 and bimodally at 150–250 and 300–350 km in 2014 for RLKI and tended to be farther in 2013 compared to those in 2014 for TBMU. Plasma levels of corticosterone did not differ between the years in RLKI but differed in TBMU, showing higher levels of physiological stress incurred by murres in 2013, the year of relatively cooler sea surface temperatures with later sea-ice retreat. δ 13 N (a proxy of trophic level of prey) did not differ between the years in either RLKI or TBMU. These results suggest that the response of ecosystem dynamics to climate variability in the southeastern Bering Sea may differ between the ocean basin and continental shelf regions, which, in turn, may generate differential responses in seabirds relying on those habitats for foraging. |
format |
Article in Journal/Newspaper |
author |
T. Yamamoto N. Kokubun D. M. Kikuchi N. Sato A. Takahashi A. P. Will A. S. Kitaysky Y. Watanuki |
author_facet |
T. Yamamoto N. Kokubun D. M. Kikuchi N. Sato A. Takahashi A. P. Will A. S. Kitaysky Y. Watanuki |
author_sort |
T. Yamamoto |
title |
Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea |
title_short |
Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea |
title_full |
Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea |
title_fullStr |
Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea |
title_full_unstemmed |
Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea |
title_sort |
differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern bering sea |
publisher |
Copernicus Publications |
publishDate |
2016 |
url |
https://doi.org/10.5194/bg-13-2405-2016 https://doaj.org/article/cdfa0ca06a584ea18ce87f5a1f9ebe29 |
geographic |
Bering Sea |
geographic_facet |
Bering Sea |
genre |
Bering Sea Sea ice Uria lomvia uria |
genre_facet |
Bering Sea Sea ice Uria lomvia uria |
op_source |
Biogeosciences, Vol 13, Iss 8, Pp 2405-2414 (2016) |
op_relation |
http://www.biogeosciences.net/13/2405/2016/bg-13-2405-2016.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-13-2405-2016 https://doaj.org/article/cdfa0ca06a584ea18ce87f5a1f9ebe29 |
op_doi |
https://doi.org/10.5194/bg-13-2405-2016 |
container_title |
Biogeosciences |
container_volume |
13 |
container_issue |
8 |
container_start_page |
2405 |
op_container_end_page |
2414 |
_version_ |
1766377662969806848 |