Southern sea lions and artisanal fisheries in Piriápolis, Uruguay: Interactions in 1997, 2001, and 2002

Southern sea lions and artisanal fisheries in Piriápolis, Uruguay: Interactions in 1997, 2001, and 2002

D. Szteren, and C. Lezama

Southern sea lions and artisanal fisheries in Piriápolis, Uruguay: Interactions in 1997, 2001, and 2002This is part of Sea Lions of the World
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Description

Interactions between marine mammals and fisheries are a worldwide problem that occur whenever fishing activities coincide spatially with marine mammals feeding grounds. In Uruguay this topic was first studied in 1997, and continued in 2001 and 2002. Here we compare the interactions over 3 years at Piriápolis fishing port. Onboard observations during fishing operations were done between July and January, totaling 16 samplings in 1997, 15 in 2001, and 9 in 2002.

The frequency of sea lion sightings decreased over time (56.3%,
46.7%, and 22.2%), as did the mean number of sea lions (1.13, 0.80, 0.44), but not significantly. Sea lion interactions also decreased with time from 75% in 1997 to 33.3% in 2002. CPUEs with longlines diminished with time, but with gillnets were higher in 2001. The frequency of interactions diminished with time (from 75% to 33%), but this was not clearly reflected in an increase of CPUE, because in most cases they were not significantly related to the presence of interactions. Since interactions or the record
of predation during fishing operations were not reflected in lower CPUE, we conclude that sea lions were not the only cause of the low and variable catches.

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