Effects of whaling on the structure of the Southern Ocean food web: insights on the "krill surplus" from ecosystem modelling.
The aim of this study was to examine the ecological plausibility of the "krill surplus" hypothesis and the effects of whaling on the Southern Ocean food web using mass-balance ecosystem modelling. The depletion trajectory and unexploited biomass of each rorqual population in the Antarctic...
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ftdoajarticles:oai:doaj.org/article:23eff39330c443d7a9b27f1e75345fff 2023-05-15T13:34:19+02:00 Effects of whaling on the structure of the Southern Ocean food web: insights on the "krill surplus" from ecosystem modelling. Szymon Surma Evgeny A Pakhomov Tony J Pitcher 2014-01-01T00:00:00Z https://doi.org/10.1371/journal.pone.0114978 https://doaj.org/article/23eff39330c443d7a9b27f1e75345fff EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC4269391?pdf=render https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0114978 https://doaj.org/article/23eff39330c443d7a9b27f1e75345fff PLoS ONE, Vol 9, Iss 12, p e114978 (2014) Medicine R Science Q article 2014 ftdoajarticles https://doi.org/10.1371/journal.pone.0114978 2022-12-31T12:49:41Z The aim of this study was to examine the ecological plausibility of the "krill surplus" hypothesis and the effects of whaling on the Southern Ocean food web using mass-balance ecosystem modelling. The depletion trajectory and unexploited biomass of each rorqual population in the Antarctic was reconstructed using yearly catch records and a set of species-specific surplus production models. The resulting estimates of the unexploited biomass of Antarctic rorquals were used to construct an Ecopath model of the Southern Ocean food web existing in 1900. The rorqual depletion trajectory was then used in an Ecosim scenario to drive rorqual biomasses and examine the "krill surplus" phenomenon and whaling effects on the food web in the years 1900-2008. An additional suite of Ecosim scenarios reflecting several hypothetical trends in Southern Ocean primary productivity were employed to examine the effect of bottom-up forcing on the documented krill biomass trend. The output of the Ecosim scenarios indicated that while the "krill surplus" hypothesis is a plausible explanation of the biomass trends observed in some penguin and pinniped species in the mid-20th century, the excess krill biomass was most likely eliminated by a rapid decline in primary productivity in the years 1975-1995. Our findings suggest that changes in physical conditions in the Southern Ocean during this time period could have eliminated the ecological effects of rorqual depletion, although the mechanism responsible is currently unknown. Furthermore, a decline in iron bioavailability due to rorqual depletion may have contributed to the rapid decline in overall Southern Ocean productivity during the last quarter of the 20th century. The results of this study underscore the need for further research on historical changes in the roles of top-down and bottom-up forcing in structuring the Southern Ocean food web. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Directory of Open Access Journals: DOAJ Articles Antarctic Southern Ocean The Antarctic Rorqual ENVELOPE(-62.311,-62.311,-65.648,-65.648) PLoS ONE 9 12 e114978 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Medicine R Science Q |
spellingShingle |
Medicine R Science Q Szymon Surma Evgeny A Pakhomov Tony J Pitcher Effects of whaling on the structure of the Southern Ocean food web: insights on the "krill surplus" from ecosystem modelling. |
topic_facet |
Medicine R Science Q |
description |
The aim of this study was to examine the ecological plausibility of the "krill surplus" hypothesis and the effects of whaling on the Southern Ocean food web using mass-balance ecosystem modelling. The depletion trajectory and unexploited biomass of each rorqual population in the Antarctic was reconstructed using yearly catch records and a set of species-specific surplus production models. The resulting estimates of the unexploited biomass of Antarctic rorquals were used to construct an Ecopath model of the Southern Ocean food web existing in 1900. The rorqual depletion trajectory was then used in an Ecosim scenario to drive rorqual biomasses and examine the "krill surplus" phenomenon and whaling effects on the food web in the years 1900-2008. An additional suite of Ecosim scenarios reflecting several hypothetical trends in Southern Ocean primary productivity were employed to examine the effect of bottom-up forcing on the documented krill biomass trend. The output of the Ecosim scenarios indicated that while the "krill surplus" hypothesis is a plausible explanation of the biomass trends observed in some penguin and pinniped species in the mid-20th century, the excess krill biomass was most likely eliminated by a rapid decline in primary productivity in the years 1975-1995. Our findings suggest that changes in physical conditions in the Southern Ocean during this time period could have eliminated the ecological effects of rorqual depletion, although the mechanism responsible is currently unknown. Furthermore, a decline in iron bioavailability due to rorqual depletion may have contributed to the rapid decline in overall Southern Ocean productivity during the last quarter of the 20th century. The results of this study underscore the need for further research on historical changes in the roles of top-down and bottom-up forcing in structuring the Southern Ocean food web. |
format |
Article in Journal/Newspaper |
author |
Szymon Surma Evgeny A Pakhomov Tony J Pitcher |
author_facet |
Szymon Surma Evgeny A Pakhomov Tony J Pitcher |
author_sort |
Szymon Surma |
title |
Effects of whaling on the structure of the Southern Ocean food web: insights on the "krill surplus" from ecosystem modelling. |
title_short |
Effects of whaling on the structure of the Southern Ocean food web: insights on the "krill surplus" from ecosystem modelling. |
title_full |
Effects of whaling on the structure of the Southern Ocean food web: insights on the "krill surplus" from ecosystem modelling. |
title_fullStr |
Effects of whaling on the structure of the Southern Ocean food web: insights on the "krill surplus" from ecosystem modelling. |
title_full_unstemmed |
Effects of whaling on the structure of the Southern Ocean food web: insights on the "krill surplus" from ecosystem modelling. |
title_sort |
effects of whaling on the structure of the southern ocean food web: insights on the "krill surplus" from ecosystem modelling. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2014 |
url |
https://doi.org/10.1371/journal.pone.0114978 https://doaj.org/article/23eff39330c443d7a9b27f1e75345fff |
long_lat |
ENVELOPE(-62.311,-62.311,-65.648,-65.648) |
geographic |
Antarctic Southern Ocean The Antarctic Rorqual |
geographic_facet |
Antarctic Southern Ocean The Antarctic Rorqual |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
PLoS ONE, Vol 9, Iss 12, p e114978 (2014) |
op_relation |
http://europepmc.org/articles/PMC4269391?pdf=render https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0114978 https://doaj.org/article/23eff39330c443d7a9b27f1e75345fff |
op_doi |
https://doi.org/10.1371/journal.pone.0114978 |
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PLoS ONE |
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9 |
container_issue |
12 |
container_start_page |
e114978 |
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