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Trophic effects of fishing southern rock lobster Jasus edwardsii shown by combined fatty acid and stable isotope analyses

Citation

Guest, MA and Frusher, SD and Nichols, PD and Johnson, CR and Wheatley, KE, Trophic effects of fishing southern rock lobster Jasus edwardsii shown by combined fatty acid and stable isotope analyses, Marine Ecology Progress Series, 388, (August) pp. 169-184. ISSN 0171-8630 (2009) [Refereed Article]


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Copyright Statement

Copyright Inter-Research 2009

Official URL: http://www.int-res.com/abstracts/meps/v388/p169-18...

DOI: doi:10.3354/meps08096

Abstract

The southern rock lobster Jasus edwardsii is a commercial species that has benefited from the complete protection offered by no-take reserves, with higher abundances and larger animals recorded in reserves than in adjacent fished areas. What remains unclear is whether there is any change in the diet of lobsters in reserves, for example, as a result of increased intraspecific competition for food. We used combined chemical tracers to examine the diet of lobsters in fished and reserve areas in 2 bioregions in eastern Tasmania. 15N values of lobsters were richer in fished than in reserve areas, indicating that lobsters eat a greater proportion of food items from higher trophic levels in fished areas. Mixing models suggest that ascidians, sea urchins and the turbinid gastropod were all important food sources for lobsters, but the importance of these food items differed between bioregions. This spatial variability may suggest that the small size of the reserve in one bioregion is inadequate at ensuring the diet of lobsters is protected from fishing pressure. Fatty acid profiles of lobsters supported the importance of these food sources to lobsters. Differences between bioregions, or inside and outside of reserves, were not apparent using fatty acids. The present study highlights that lobster fishing has the capacity to alter the trophic status of prey for generalist predators and suggests that fatty acid analyses may be limited in detecting changes in the dietary composition of such generalist feeders

Item Details

Item Type:Refereed Article
Keywords:effects of fishing, food webs, marine protected areas, stable isotopes, fatty acids
Research Division:Agricultural and Veterinary Sciences
Research Group:Animal Production
Research Field:Animal Management
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - Aquaculture
Objective Field:Aquaculture Rock Lobster
Author:Guest, MA (Dr Michaela Guest)
Author:Frusher, SD (Professor Stewart Frusher)
Author:Nichols, PD (Dr Peter Nichols)
Author:Johnson, CR (Professor Craig Johnson)
Author:Wheatley, KE (Dr Kathryn Wheatley)
ID Code:58640
Year Published:2009
Web of Science® Times Cited:18
Deposited By:Zoology
Deposited On:2009-10-16
Last Modified:2013-01-02
Downloads:760 View Download Statistics

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