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...
Published in: | Biogeosciences |
---|---|
Main Authors: | , , , , , , , |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/bg-13-2405-2016 https://www.biogeosciences.net/13/2405/2016/ |
id |
ftcopernicus:oai:publications.copernicus.org:bg32570 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:bg32570 2023-05-15T15:43:29+02:00 Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea Yamamoto, Takashi Kokubun, Nobuo Kikuchi, Dale M. Sato, Nobuhiko Takahashi, Akinori Will, Alexis P. Kitaysky, Alexander S. Watanuki, Yutaka 2018-09-27 application/pdf https://doi.org/10.5194/bg-13-2405-2016 https://www.biogeosciences.net/13/2405/2016/ eng eng doi:10.5194/bg-13-2405-2016 https://www.biogeosciences.net/13/2405/2016/ eISSN: 1726-4189 Text 2018 ftcopernicus https://doi.org/10.5194/bg-13-2405-2016 2019-12-24T09:52:35Z 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. Text Bering Sea Sea ice Uria lomvia uria Copernicus Publications: E-Journals Bering Sea Biogeosciences 13 8 2405 2414 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
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 |
Text |
author |
Yamamoto, Takashi Kokubun, Nobuo Kikuchi, Dale M. Sato, Nobuhiko Takahashi, Akinori Will, Alexis P. Kitaysky, Alexander S. Watanuki, Yutaka |
spellingShingle |
Yamamoto, Takashi Kokubun, Nobuo Kikuchi, Dale M. Sato, Nobuhiko Takahashi, Akinori Will, Alexis P. Kitaysky, Alexander S. Watanuki, Yutaka Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea |
author_facet |
Yamamoto, Takashi Kokubun, Nobuo Kikuchi, Dale M. Sato, Nobuhiko Takahashi, Akinori Will, Alexis P. Kitaysky, Alexander S. Watanuki, Yutaka |
author_sort |
Yamamoto, Takashi |
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 |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-13-2405-2016 https://www.biogeosciences.net/13/2405/2016/ |
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 |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-13-2405-2016 https://www.biogeosciences.net/13/2405/2016/ |
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_ |
1766377657151258624 |