Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000
This paper summarizes the results of krill demographic studies from the Commission for the Conservation of Antarctic Marine Living Resources 2000 Survey-a large-scale krill survey across the Scotia Sea conducted in January/February 2000. Standard Rectangular Midwater Trawl net tows were carried out...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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Online Access: | http://nora.nerc.ac.uk/id/eprint/12414/ http://www.sciencedirect.com/science/article/pii/S0967064504000785 |
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ftnerc:oai:nora.nerc.ac.uk:12414 2023-05-15T13:45:11+02:00 Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000 Siegel, V. Kawaguchi, S. Ward, P. Litvinov, F. Sushin, V. Loeb, V. Watkins, J. 2004 http://nora.nerc.ac.uk/id/eprint/12414/ http://www.sciencedirect.com/science/article/pii/S0967064504000785 unknown Elsevier Siegel, V.; Kawaguchi, S.; Ward, P.; Litvinov, F.; Sushin, V.; Loeb, V.; Watkins, J. 2004 Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000. Deep-Sea Research Part II, 51 (12-13). 1253-1273. https://doi.org/10.1016/j.dsr2.2004.06.013 <https://doi.org/10.1016/j.dsr2.2004.06.013> Marine Sciences Zoology Ecology and Environment Publication - Article PeerReviewed 2004 ftnerc https://doi.org/10.1016/j.dsr2.2004.06.013 2023-02-04T19:28:00Z This paper summarizes the results of krill demographic studies from the Commission for the Conservation of Antarctic Marine Living Resources 2000 Survey-a large-scale krill survey across the Scotia Sea conducted in January/February 2000. Standard Rectangular Midwater Trawl net tows were carried out at midnight and midday stations between 20degrees and 70degreesW south of the Polar Front. The overall mean numerical density and biomass of krill estimated from nets (247 krill per 1000 m(3) and 18.7 g m(-2), respectively) were similar to lower values reported previously for the Southwest Atlantic, and comparable with high values for other regions of the Southern Ocean. Krill varied in mean size across the survey area, with cluster analyses showing three distinct groups of length-frequency distribution. Small juvenile and immature krill occurred east of the South Orkney Islands. Adult krill < 50 mm dominated the shelf areas of the Antarctic Peninsula and to the north of the juvenile stock across the Scotia Sea. Adult krill > 50 mm were mostly restricted to the west of the South Orkney Islands. Maturity stage composition indicated that peak spawning occurred before early February. Distribution of the spawning stock showed two hotspots, the first between the South Shetland and South Orkney Islands, and the second around the South Sandwich Islands. Reproductive krill were largely absent in the central Scotia Sea and around South Georgia. Krill larvae concentrations occurred slightly to the east of the spawning stock. Mean density of larvae in the western Scotia Sea was 2044 m(-2), but only scattered aggregations of larvae were recorded east of 36degreesW (2 m(-2)). Recruitment indices for 1- and 2-year-old krill were low in the western part of the survey area, the outflow from the Bellingshausen Sea/Antarctic Peninsula region (R-1 = 0.0, R-2 = 0.11) indicating spawning failure and/or poor recruitment for several years. In the eastern part of the survey area, mostly the outflow of the Weddell Sea, recruitment ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Bellingshausen Sea Scotia Sea South Orkney Islands South Sandwich Islands Southern Ocean Weddell Sea Natural Environment Research Council: NERC Open Research Archive Antarctic Southern Ocean The Antarctic Antarctic Peninsula Weddell Sea Scotia Sea Sandwich Islands South Sandwich Islands Bellingshausen Sea Weddell South Georgia ENVELOPE(-33.000,-33.000,-56.000,-56.000) South Orkney Islands ENVELOPE(-45.500,-45.500,-60.583,-60.583) Deep Sea Research Part II: Topical Studies in Oceanography 51 12-13 1253 1273 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Marine Sciences Zoology Ecology and Environment |
spellingShingle |
Marine Sciences Zoology Ecology and Environment Siegel, V. Kawaguchi, S. Ward, P. Litvinov, F. Sushin, V. Loeb, V. Watkins, J. Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000 |
topic_facet |
Marine Sciences Zoology Ecology and Environment |
description |
This paper summarizes the results of krill demographic studies from the Commission for the Conservation of Antarctic Marine Living Resources 2000 Survey-a large-scale krill survey across the Scotia Sea conducted in January/February 2000. Standard Rectangular Midwater Trawl net tows were carried out at midnight and midday stations between 20degrees and 70degreesW south of the Polar Front. The overall mean numerical density and biomass of krill estimated from nets (247 krill per 1000 m(3) and 18.7 g m(-2), respectively) were similar to lower values reported previously for the Southwest Atlantic, and comparable with high values for other regions of the Southern Ocean. Krill varied in mean size across the survey area, with cluster analyses showing three distinct groups of length-frequency distribution. Small juvenile and immature krill occurred east of the South Orkney Islands. Adult krill < 50 mm dominated the shelf areas of the Antarctic Peninsula and to the north of the juvenile stock across the Scotia Sea. Adult krill > 50 mm were mostly restricted to the west of the South Orkney Islands. Maturity stage composition indicated that peak spawning occurred before early February. Distribution of the spawning stock showed two hotspots, the first between the South Shetland and South Orkney Islands, and the second around the South Sandwich Islands. Reproductive krill were largely absent in the central Scotia Sea and around South Georgia. Krill larvae concentrations occurred slightly to the east of the spawning stock. Mean density of larvae in the western Scotia Sea was 2044 m(-2), but only scattered aggregations of larvae were recorded east of 36degreesW (2 m(-2)). Recruitment indices for 1- and 2-year-old krill were low in the western part of the survey area, the outflow from the Bellingshausen Sea/Antarctic Peninsula region (R-1 = 0.0, R-2 = 0.11) indicating spawning failure and/or poor recruitment for several years. In the eastern part of the survey area, mostly the outflow of the Weddell Sea, recruitment ... |
format |
Article in Journal/Newspaper |
author |
Siegel, V. Kawaguchi, S. Ward, P. Litvinov, F. Sushin, V. Loeb, V. Watkins, J. |
author_facet |
Siegel, V. Kawaguchi, S. Ward, P. Litvinov, F. Sushin, V. Loeb, V. Watkins, J. |
author_sort |
Siegel, V. |
title |
Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000 |
title_short |
Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000 |
title_full |
Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000 |
title_fullStr |
Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000 |
title_full_unstemmed |
Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000 |
title_sort |
krill demography and large-scale distribution in the southwest atlantic during january/february 2000 |
publisher |
Elsevier |
publishDate |
2004 |
url |
http://nora.nerc.ac.uk/id/eprint/12414/ http://www.sciencedirect.com/science/article/pii/S0967064504000785 |
long_lat |
ENVELOPE(-33.000,-33.000,-56.000,-56.000) ENVELOPE(-45.500,-45.500,-60.583,-60.583) |
geographic |
Antarctic Southern Ocean The Antarctic Antarctic Peninsula Weddell Sea Scotia Sea Sandwich Islands South Sandwich Islands Bellingshausen Sea Weddell South Georgia South Orkney Islands |
geographic_facet |
Antarctic Southern Ocean The Antarctic Antarctic Peninsula Weddell Sea Scotia Sea Sandwich Islands South Sandwich Islands Bellingshausen Sea Weddell South Georgia South Orkney Islands |
genre |
Antarc* Antarctic Antarctic Peninsula Bellingshausen Sea Scotia Sea South Orkney Islands South Sandwich Islands Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Bellingshausen Sea Scotia Sea South Orkney Islands South Sandwich Islands Southern Ocean Weddell Sea |
op_relation |
Siegel, V.; Kawaguchi, S.; Ward, P.; Litvinov, F.; Sushin, V.; Loeb, V.; Watkins, J. 2004 Krill demography and large-scale distribution in the southwest Atlantic during January/February 2000. Deep-Sea Research Part II, 51 (12-13). 1253-1273. https://doi.org/10.1016/j.dsr2.2004.06.013 <https://doi.org/10.1016/j.dsr2.2004.06.013> |
op_doi |
https://doi.org/10.1016/j.dsr2.2004.06.013 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
51 |
container_issue |
12-13 |
container_start_page |
1253 |
op_container_end_page |
1273 |
_version_ |
1766215081575579648 |