nerc.ac.uk

The impact of predation by marine mammals on Patagonian toothfish longline fisheries

Söffker, Marta; Trathan, Phil; Clark, James; Collins, Martin A.; Belchier, Mark; Scott, Robert. 2015 The impact of predation by marine mammals on Patagonian toothfish longline fisheries. PLOS ONE, 10 (3), e0118113. 10.1371/journal.pone.0118113

Before downloading, please read NORA policies.
[img]
Preview
Text
Marta.pdf - Published Version
Available under License Creative Commons Attribution.

Download (914kB) | Preview

Abstract/Summary

Predatory interaction of marine mammals with longline fisheries is observed globally, leading to partial or complete loss of the catch and in some parts of the world to considerable financial loss. Depredation can also create additional unrecorded fishing mortality of a stock and has the potential to introduce bias to stock assessments. Here we aim to characterise depredation in the Patagonian toothfish (Dissostichus eleginoides) fishery around South Georgia focusing on the spatio-temporal component of these interactions. Antarctic fur seals (Arctocephalus gazella), sperm whales (Physeter macrocephalus), and orcas (Orcinus orca) frequently feed on fish hooked on longlines around South Georgia. A third of longlines encounter sperm whales, but loss of catch due to sperm whales is insignificant when compared to that due to orcas, which interact with only 5% of longlines but can take more than half of the catch in some cases. Orca depredation around South Georgia is spatially limited and focused in areas of putative migration routes, and the impact is compounded as a result of the fishery also concentrating in those areas at those times. Understanding the seasonal behaviour of orcas and the spatial and temporal distribution of “depredation hot spots” can reduce marine mammal interactions, will improve assessment and management of the stock and contribute to increased operational efficiency of the fishery. Such information is valuable in the effort to resolve the human-mammal conflict for resources.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1371/journal.pone.0118113
Programmes: BAS Programmes > Polar Science for Planet Earth (2009 - ) > Ecosystems
ISSN: 1932-6203
Additional Keywords: sperm whales, seals, fisheries, Antarctica, killer whales
Date made live: 16 Mar 2015 10:47 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/510148

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...