Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage
We used the instantaneous growth rate method to determine the effects of food, temperature, krill length, sex, and maturity stage on in situ summer growth of krill across the southwest Atlantic sector of the Southern Ocean. The main aims were to examine the separate effects of each variable and to g...
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American Society of Limnology and Oceanography
2006
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Online Access: | http://nora.nerc.ac.uk/id/eprint/10/ https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2006.51.2.0973 |
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ftnerc:oai:nora.nerc.ac.uk:10 2024-06-09T07:39:21+00:00 Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage Atkinson, Angus Shreeve, Rachael S. Hirst, Andrew G. Rothery, Peter Tarling, Geraint A. Pond, David W. Korb, Rebecca E. Murphy, Eugene J. Watkins, Jonathon L. 2006-03 http://nora.nerc.ac.uk/id/eprint/10/ https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2006.51.2.0973 unknown American Society of Limnology and Oceanography Atkinson, Angus; Shreeve, Rachael S.; Hirst, Andrew G.; Rothery, Peter; Tarling, Geraint A. orcid:0000-0002-3753-5899 Pond, David W.; Korb, Rebecca E.; Murphy, Eugene J. orcid:0000-0002-7369-9196 Watkins, Jonathon L. 2006 Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage. Limnology and Oceanography, 51 (2). 973-987. https://doi.org/10.4319/lo.2006.51.2.0973 <https://doi.org/10.4319/lo.2006.51.2.0973> Marine Sciences Zoology Publication - Article PeerReviewed 2006 ftnerc https://doi.org/10.4319/lo.2006.51.2.0973 2024-05-15T08:39:04Z We used the instantaneous growth rate method to determine the effects of food, temperature, krill length, sex, and maturity stage on in situ summer growth of krill across the southwest Atlantic sector of the Southern Ocean. The main aims were to examine the separate effects of each variable and to generate a predictive model of growth based on satellite-derivable environmental data. Both growth increments in length on moulting (GIs) and daily growth rates (DGRs, mm d-1) ranged greatly among the 59 swarms, from 0.58–15% and 0.013–0.32 mm d-1. However, all swarms maintained positive mean growth, even those in the low chlorophyll a (Chl a) zone of the central Scotia Sea. Among a suite of indices of food quantity and quality, large-scale monthly Chl a values from SeaWiFS predicted krill growth the best. Across our study area, the great contrast between bloom and nonbloom regions was a major factor driving variation in growth rates, obscuring more subtle effects of food quality. GIs and DGRs decreased with increasing krill length and decreased above a temperature optimum of 0.5°C. This probably reflects the onset of thermal stress at the northern limit of krill’s range. Thus, growth rates were fastest in the ice edge blooms of the southern Scotia Sea and not at South Georgia as previously suggested. This reflects both the smaller size of the krill and the colder water in the south being optimum for growth. Males tended to have higher GIs than females but longer intermoult periods, leading to similar DGRs between sexes. DGRs of equivalent-size krill tended to decrease with maturity stage, suggesting the progressive allocation of energy toward reproduction rather than somatic growth. Our maximum DGRs are higher than most literature values, equating to a 5.7% increase in mass per day. This value fits within a realistic energy budget, suggesting a maximum carbon ration of ~20% d-1. Over the whole Scotia Sea/South Georgia area, the gross turnover of krill biomass was ~1% d-1. Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Euphausia superba Scotia Sea Southern Ocean Natural Environment Research Council: NERC Open Research Archive Antarctic Scotia Sea Southern Ocean Limnology and Oceanography 51 2 973 987 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Marine Sciences Zoology |
spellingShingle |
Marine Sciences Zoology Atkinson, Angus Shreeve, Rachael S. Hirst, Andrew G. Rothery, Peter Tarling, Geraint A. Pond, David W. Korb, Rebecca E. Murphy, Eugene J. Watkins, Jonathon L. Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage |
topic_facet |
Marine Sciences Zoology |
description |
We used the instantaneous growth rate method to determine the effects of food, temperature, krill length, sex, and maturity stage on in situ summer growth of krill across the southwest Atlantic sector of the Southern Ocean. The main aims were to examine the separate effects of each variable and to generate a predictive model of growth based on satellite-derivable environmental data. Both growth increments in length on moulting (GIs) and daily growth rates (DGRs, mm d-1) ranged greatly among the 59 swarms, from 0.58–15% and 0.013–0.32 mm d-1. However, all swarms maintained positive mean growth, even those in the low chlorophyll a (Chl a) zone of the central Scotia Sea. Among a suite of indices of food quantity and quality, large-scale monthly Chl a values from SeaWiFS predicted krill growth the best. Across our study area, the great contrast between bloom and nonbloom regions was a major factor driving variation in growth rates, obscuring more subtle effects of food quality. GIs and DGRs decreased with increasing krill length and decreased above a temperature optimum of 0.5°C. This probably reflects the onset of thermal stress at the northern limit of krill’s range. Thus, growth rates were fastest in the ice edge blooms of the southern Scotia Sea and not at South Georgia as previously suggested. This reflects both the smaller size of the krill and the colder water in the south being optimum for growth. Males tended to have higher GIs than females but longer intermoult periods, leading to similar DGRs between sexes. DGRs of equivalent-size krill tended to decrease with maturity stage, suggesting the progressive allocation of energy toward reproduction rather than somatic growth. Our maximum DGRs are higher than most literature values, equating to a 5.7% increase in mass per day. This value fits within a realistic energy budget, suggesting a maximum carbon ration of ~20% d-1. Over the whole Scotia Sea/South Georgia area, the gross turnover of krill biomass was ~1% d-1. |
format |
Article in Journal/Newspaper |
author |
Atkinson, Angus Shreeve, Rachael S. Hirst, Andrew G. Rothery, Peter Tarling, Geraint A. Pond, David W. Korb, Rebecca E. Murphy, Eugene J. Watkins, Jonathon L. |
author_facet |
Atkinson, Angus Shreeve, Rachael S. Hirst, Andrew G. Rothery, Peter Tarling, Geraint A. Pond, David W. Korb, Rebecca E. Murphy, Eugene J. Watkins, Jonathon L. |
author_sort |
Atkinson, Angus |
title |
Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage |
title_short |
Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage |
title_full |
Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage |
title_fullStr |
Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage |
title_full_unstemmed |
Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage |
title_sort |
natural growth rates in antarctic krill (euphausia superba): ii. predictive models based on food, temperature, body length, sex, and maturity stage |
publisher |
American Society of Limnology and Oceanography |
publishDate |
2006 |
url |
http://nora.nerc.ac.uk/id/eprint/10/ https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2006.51.2.0973 |
geographic |
Antarctic Scotia Sea Southern Ocean |
geographic_facet |
Antarctic Scotia Sea Southern Ocean |
genre |
Antarc* Antarctic Antarctic Krill Euphausia superba Scotia Sea Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Krill Euphausia superba Scotia Sea Southern Ocean |
op_relation |
Atkinson, Angus; Shreeve, Rachael S.; Hirst, Andrew G.; Rothery, Peter; Tarling, Geraint A. orcid:0000-0002-3753-5899 Pond, David W.; Korb, Rebecca E.; Murphy, Eugene J. orcid:0000-0002-7369-9196 Watkins, Jonathon L. 2006 Natural growth rates in Antarctic krill (Euphausia superba): II. Predictive models based on food, temperature, body length, sex, and maturity stage. Limnology and Oceanography, 51 (2). 973-987. https://doi.org/10.4319/lo.2006.51.2.0973 <https://doi.org/10.4319/lo.2006.51.2.0973> |
op_doi |
https://doi.org/10.4319/lo.2006.51.2.0973 |
container_title |
Limnology and Oceanography |
container_volume |
51 |
container_issue |
2 |
container_start_page |
973 |
op_container_end_page |
987 |
_version_ |
1801378852681809920 |