Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula
Antarctic krill Euphausia superba are a key component of food webs in the maritime West Antarctic Peninsula, and their life history is tied to the seasonal cycles of sea ice and primary production in the region. Previous work has shown a general in-shore migration of krill in winter in this region;...
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ftunivrhodeislan:oai:digitalcommons.uri.edu:gsofacpubs-1543 2024-09-15T17:48:39+00:00 Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula Cleary, Alison C. Durbin, Edward G. Casas, Maria C. Zhou, Meng 2016-01-01T08:00:00Z application/pdf https://digitalcommons.uri.edu/gsofacpubs/574 https://doi.org/10.3354/meps11772 https://digitalcommons.uri.edu/context/gsofacpubs/article/1543/viewcontent/Cleary_etal_WinterDistribution_2016.pdf unknown DigitalCommons@URI https://digitalcommons.uri.edu/gsofacpubs/574 doi:10.3354/meps11772 https://digitalcommons.uri.edu/context/gsofacpubs/article/1543/viewcontent/Cleary_etal_WinterDistribution_2016.pdf http://creativecommons.org/licenses/by/4.0/ Graduate School of Oceanography Faculty Publications text 2016 ftunivrhodeislan https://doi.org/10.3354/meps11772 2024-08-21T00:09:33Z Antarctic krill Euphausia superba are a key component of food webs in the maritime West Antarctic Peninsula, and their life history is tied to the seasonal cycles of sea ice and primary production in the region. Previous work has shown a general in-shore migration of krill in winter in this region; however, the very near-shore has not often been sampled as part of these surveys. We investigated distribution, abundance, and size structure of krill in 3 fjordic bays along the peninsula, and in the adjacent Gerlache Strait area using vertically stratified MOCNESS net tows and ADCP acoustic biomass estimates. Krill abundance was high within bays, with net estimated densities exceeding 60 krill m-3, while acoustic estimates were an order of magnitude higher. Krill within bays were larger than krill in the Gerlache Strait. Within bays, krill aggregations were observed near the seafloor during the day with aggregations extending to the sediment interface, and exhibited diel vertical migration higher into the water column at night. We suggest these high winter krill abundances within fjords are indicative of an active seasonal migration by krill in the peninsula region. Potential drivers for such a migration include reduced advective losses and costs, and availability of sediment food resources within fjords. Seasonally near-shore krill may also affect stock and recruitment assessments and may have implications for managing the krill fishery in this area. Text Antarc* Antarctic Antarctic Krill Antarctic Peninsula Euphausia superba Sea ice University of Rhode Island: DigitalCommons@URI Marine Ecology Progress Series 552 115 129 |
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University of Rhode Island: DigitalCommons@URI |
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ftunivrhodeislan |
language |
unknown |
description |
Antarctic krill Euphausia superba are a key component of food webs in the maritime West Antarctic Peninsula, and their life history is tied to the seasonal cycles of sea ice and primary production in the region. Previous work has shown a general in-shore migration of krill in winter in this region; however, the very near-shore has not often been sampled as part of these surveys. We investigated distribution, abundance, and size structure of krill in 3 fjordic bays along the peninsula, and in the adjacent Gerlache Strait area using vertically stratified MOCNESS net tows and ADCP acoustic biomass estimates. Krill abundance was high within bays, with net estimated densities exceeding 60 krill m-3, while acoustic estimates were an order of magnitude higher. Krill within bays were larger than krill in the Gerlache Strait. Within bays, krill aggregations were observed near the seafloor during the day with aggregations extending to the sediment interface, and exhibited diel vertical migration higher into the water column at night. We suggest these high winter krill abundances within fjords are indicative of an active seasonal migration by krill in the peninsula region. Potential drivers for such a migration include reduced advective losses and costs, and availability of sediment food resources within fjords. Seasonally near-shore krill may also affect stock and recruitment assessments and may have implications for managing the krill fishery in this area. |
format |
Text |
author |
Cleary, Alison C. Durbin, Edward G. Casas, Maria C. Zhou, Meng |
spellingShingle |
Cleary, Alison C. Durbin, Edward G. Casas, Maria C. Zhou, Meng Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula |
author_facet |
Cleary, Alison C. Durbin, Edward G. Casas, Maria C. Zhou, Meng |
author_sort |
Cleary, Alison C. |
title |
Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula |
title_short |
Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula |
title_full |
Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula |
title_fullStr |
Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula |
title_full_unstemmed |
Winter distribution and size structure of Antarctic krill Euphausia superba populations in-shore along the West Antarctic Peninsula |
title_sort |
winter distribution and size structure of antarctic krill euphausia superba populations in-shore along the west antarctic peninsula |
publisher |
DigitalCommons@URI |
publishDate |
2016 |
url |
https://digitalcommons.uri.edu/gsofacpubs/574 https://doi.org/10.3354/meps11772 https://digitalcommons.uri.edu/context/gsofacpubs/article/1543/viewcontent/Cleary_etal_WinterDistribution_2016.pdf |
genre |
Antarc* Antarctic Antarctic Krill Antarctic Peninsula Euphausia superba Sea ice |
genre_facet |
Antarc* Antarctic Antarctic Krill Antarctic Peninsula Euphausia superba Sea ice |
op_source |
Graduate School of Oceanography Faculty Publications |
op_relation |
https://digitalcommons.uri.edu/gsofacpubs/574 doi:10.3354/meps11772 https://digitalcommons.uri.edu/context/gsofacpubs/article/1543/viewcontent/Cleary_etal_WinterDistribution_2016.pdf |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3354/meps11772 |
container_title |
Marine Ecology Progress Series |
container_volume |
552 |
container_start_page |
115 |
op_container_end_page |
129 |
_version_ |
1810290128187293696 |