Dividing up the pie: whales, fish, and humans as competitors
International audience Similarly structured food web models of four coastal ecosystems (Northern California Current, Central Gulf of Alaska, Georges Bank, southwestern Antarctic Peninsula) were used to investigate competition among whales, fishes, pinnipeds, and humans. Two analysis strategies simul...
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ftunivtoulon:oai:HAL:hal-00950119v1 2023-12-31T09:59:43+01:00 Dividing up the pie: whales, fish, and humans as competitors Ruzicka, James J. Steele, John H. Ballerini, Tosca Gaichas, Sarah K. Ainley, David G. 5 Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS) 2013 https://hal.science/hal-00950119 en eng HAL CCSD Elsevier hal-00950119 https://hal.science/hal-00950119 ISSN: 0079-6611 Progress in Oceanography https://hal.science/hal-00950119 Progress in Oceanography, 2013, 116, pp.207-219 [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDV.EE.ECO]Life Sciences [q-bio]/Ecology environment/Ecosystems info:eu-repo/semantics/article Journal articles 2013 ftunivtoulon 2023-12-05T23:34:31Z International audience Similarly structured food web models of four coastal ecosystems (Northern California Current, Central Gulf of Alaska, Georges Bank, southwestern Antarctic Peninsula) were used to investigate competition among whales, fishes, pinnipeds, and humans. Two analysis strategies simulated the effects of historic baleen and odontocete whale abundances across all trophic levels: food web structure scenarios and time-dynamic scenarios. Direct competition between whales and commercial fisheries is small at current whale abundances; whales and fisheries each take similar proportions of annual pelagic fish production (4-7%). Scenarios show that as whale populations grow, indirect competition between whales and fish for zooplankton would more likely impact fishery production than would direct competition for fish between whales and commercial fisheries. Increased baleen whale abundance would have greater and broader indirect effects on upper trophic levels and fisheries than a similar increase in odontocete abundance. Time-dynamic scenarios, which allow for the evolution of compensatory mechanisms, showed more modest impacts than structural scenarios, which show the immediate impacts of altered energy pathways. Structural scenarios show that in terms of energy availability, there is potential for large increases in whale abundance without major changes to existing food web structures and without substantial reduction of fishery production. For each ecosystem, a five-fold increase in baleen whale abundance could be supported with minor disruptions to existing energy flow pathways. However, such an increase would remain below historical population levels for many cetaceans. A larger expansion (20X) could be accommodated only with large reductions in energy flow to competitor groups. The scope for odontocete expansion varies between ecosystems but may be more restricted than the scope for baleen expansion because they feed at higher, less productive trophic levels. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula baleen whale Alaska Université de Toulon: HAL |
institution |
Open Polar |
collection |
Université de Toulon: HAL |
op_collection_id |
ftunivtoulon |
language |
English |
topic |
[SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDV.EE.ECO]Life Sciences [q-bio]/Ecology environment/Ecosystems |
spellingShingle |
[SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDV.EE.ECO]Life Sciences [q-bio]/Ecology environment/Ecosystems Ruzicka, James J. Steele, John H. Ballerini, Tosca Gaichas, Sarah K. Ainley, David G. Dividing up the pie: whales, fish, and humans as competitors |
topic_facet |
[SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDV.EE.ECO]Life Sciences [q-bio]/Ecology environment/Ecosystems |
description |
International audience Similarly structured food web models of four coastal ecosystems (Northern California Current, Central Gulf of Alaska, Georges Bank, southwestern Antarctic Peninsula) were used to investigate competition among whales, fishes, pinnipeds, and humans. Two analysis strategies simulated the effects of historic baleen and odontocete whale abundances across all trophic levels: food web structure scenarios and time-dynamic scenarios. Direct competition between whales and commercial fisheries is small at current whale abundances; whales and fisheries each take similar proportions of annual pelagic fish production (4-7%). Scenarios show that as whale populations grow, indirect competition between whales and fish for zooplankton would more likely impact fishery production than would direct competition for fish between whales and commercial fisheries. Increased baleen whale abundance would have greater and broader indirect effects on upper trophic levels and fisheries than a similar increase in odontocete abundance. Time-dynamic scenarios, which allow for the evolution of compensatory mechanisms, showed more modest impacts than structural scenarios, which show the immediate impacts of altered energy pathways. Structural scenarios show that in terms of energy availability, there is potential for large increases in whale abundance without major changes to existing food web structures and without substantial reduction of fishery production. For each ecosystem, a five-fold increase in baleen whale abundance could be supported with minor disruptions to existing energy flow pathways. However, such an increase would remain below historical population levels for many cetaceans. A larger expansion (20X) could be accommodated only with large reductions in energy flow to competitor groups. The scope for odontocete expansion varies between ecosystems but may be more restricted than the scope for baleen expansion because they feed at higher, less productive trophic levels. |
author2 |
5 Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Ruzicka, James J. Steele, John H. Ballerini, Tosca Gaichas, Sarah K. Ainley, David G. |
author_facet |
Ruzicka, James J. Steele, John H. Ballerini, Tosca Gaichas, Sarah K. Ainley, David G. |
author_sort |
Ruzicka, James J. |
title |
Dividing up the pie: whales, fish, and humans as competitors |
title_short |
Dividing up the pie: whales, fish, and humans as competitors |
title_full |
Dividing up the pie: whales, fish, and humans as competitors |
title_fullStr |
Dividing up the pie: whales, fish, and humans as competitors |
title_full_unstemmed |
Dividing up the pie: whales, fish, and humans as competitors |
title_sort |
dividing up the pie: whales, fish, and humans as competitors |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://hal.science/hal-00950119 |
genre |
Antarc* Antarctic Antarctic Peninsula baleen whale Alaska |
genre_facet |
Antarc* Antarctic Antarctic Peninsula baleen whale Alaska |
op_source |
ISSN: 0079-6611 Progress in Oceanography https://hal.science/hal-00950119 Progress in Oceanography, 2013, 116, pp.207-219 |
op_relation |
hal-00950119 https://hal.science/hal-00950119 |
_version_ |
1786841452070830080 |