Foraging behavior of lactating South American sea lions (Otaria flavescens) and spatial–temporal resource overlap with the Uruguayan fisheries

2013 ◽  
Vol 88-89 ◽  
pp. 106-119 ◽  
Author(s):  
Federico G. Riet-Sapriza ◽  
Daniel P. Costa ◽  
Valentina Franco-Trecu ◽  
Yamandú Marín ◽  
Julio Chocca ◽  
...  
Keyword(s):  
Foraging Behavior ◽  
South American ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Resource Overlap

scholarly journals The predation of farmed salmon by South American sea lions (Otaria flavescens) in southern Chile

2009 ◽  
Vol 67 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Juan Vilata ◽  
Doris Oliva ◽  
Maritza Sepúlveda
Keyword(s):  
Prey Size ◽  
South American ◽  
Southern Chile ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Farmed Salmon ◽  
South American Sea Lion ◽  
Autumn And Winter ◽  
Strong Suspicion

Abstract Vilata, J., Oliva, D., and Sepúlveda, M. 2010. The predation of farmed salmon by South American sea lions (Otaria flavescens) in southern Chile. – ICES Journal of Marine Science, 67: 475–482. The South American sea lion Otaria flavescens is abundant off southern Chile. Because Chilean salmon farming has experienced an explosive growth in the past two decades, interactions between O. flavescens and this industry have increased. Fieldwork, including in situ behavioural observations, was carried out at three salmon farms off southern Chile from May to July 2008. The aim was to analyse possible patterns in the interactions and to evaluate whether they were influenced by the endogenous circa-rhythms of the species, prey size, tidal flux, and the use of an acoustic harassment device (AHD). The results showed that the attacks by O. flavescens followed seasonal patterns, with salmon predated more in autumn and winter, and daily patterns, with more interactions at night. In addition, attacks were more frequent on larger salmon, suggesting the existence of a prey-size preference. More sea lions were sighted at the ebb and flow tide peaks, when currents are stronger, suggesting that currents linked to tidal flux might facilitate the access of the sea lions to the farmed salmon. Although the use of AHDs appeared positive at one site, there is a strong suspicion that their efficacy may be site-specific.

First observations of operational interactions between bottom-trawling fisheries and South American sea lion, Otaria flavescens in south-central Chile

2012 ◽  
Vol 93 (2) ◽  
pp. 489-494 ◽  
Author(s):  
Pablo Reyes ◽  
Rodrigo Hucke-Gaete ◽  
Juan Pablo Torres-Florez
Keyword(s):  
South American ◽  
The South ◽  
Sea Lion ◽  
Central Chile ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
South American Sea Lion ◽  
South Central ◽  
By Catch ◽  
Working Day

This paper presents results of a study conducted on the trawling industrial fishery fleet of Merluccius gayi in south-central Chile, and the resulting interactions with the South American sea lion (Otaria flavescens). This study is based on observations made during September 2004, when incidental sea lion catch in the trawls was 6.3 sea lions/working day (1.2 sea lions/trawl−1). A total of 82 animals were incidentally caught, of which 12 were found dead, and the 70 remaining suffered from internal bleeding and/or fractures as a result of their capture. 83.3% of the fatalities occurred during nocturnal trawls, which comprise 30% of all observed trawls. Possible mechanisms of sea lion take are discussed. This note presents the first records of sea lions incidental by-catch by the trawler fleet along the south-east Pacific coast of Chile.

Transmission of Corynosoma australe (Acanthocephala: Polymorphidae) from fishes to South American sea lions Otaria flavescens in Patagonia, Argentina

2019 ◽  
Vol 118 (2) ◽  
pp. 433-440 ◽  
Author(s):  
Jesús S. Hernández-Orts ◽  
Francisco E. Montero ◽  
Néstor A. García ◽  
Enrique A. Crespo ◽  
Juan A. Raga ◽  
...  
Keyword(s):  
South American ◽  
Otaria Flavescens ◽  
Sea Lions

scholarly journals Interactions between the South American sea lion (Otaria flavescens) and the artisanal fishery off Coquimbo, northern Chile

2008 ◽  
Vol 65 (9) ◽  
pp. 1739-1746 ◽  
Author(s):  
Sabine Goetz ◽  
Matthias Wolff ◽  
Wolfgang Stotz ◽  
Mario J. Villegas
Keyword(s):  
South American ◽  
Northern Chile ◽  
Artisanal Fishery ◽  
The South ◽  
Sea Lion ◽  
Management Options ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
South American Sea Lion ◽  
Fishing Vessels

Abstract Goetz, S., Wolff, M., Stotz, W., and Villegas, M. J. 2008. Interactions between the South American sea lion (Otaria flavescens) and the artisanal fishery off Coquimbo, northern Chile. – ICES Journal of Marine Science, 65: 1739–1746. The South American sea lion (Otaria flavescens) forages in coastal waters, where it interacts with fisheries and causes considerable economic loss by removing some catch and damaging gear. This study describes for the fishery region of Coquimbo (Chile) where, when, and with what type of gear interactions occur, characterizes the animals involved (group size, sex, and age), and derives some management recommendations. The study was based on 55 interviews with fishers and observations aboard fishing vessels in the main fishing sectors between October 2003 and March 2004. Interactions were primarily at night (88% of interviewees fished at night), in the bay (“Bahía”) of Coquimbo (81% of interviewees fished in this sector), where shoaling fish were abundant, and with purse-seines (100% of interviewees used this gear). Although some large groups of sea lions were seen, most comprised 1–10 animals. Most animals that interacted with the fishing gear were males (67%), probably because of the different feeding strategies of the two sexes. Management options discussed include the adjustment of fisheries to foraging behaviour of sea lions, and the controlled elimination of conflicting animals.

scholarly journals South American sea lions (Otaria flavescens) and killer whales (Orcinus orca) attending chub mackerel (Scomber japonicus) commercial trawl fisheries over the Patagonian Shelf: a first report

2015 ◽  
Vol 10 (1) ◽  
pp. 48-51
Author(s):  
Juan Pablo Seco Pon ◽  
Marco Favero
Keyword(s):  
Antipredator Behaviour ◽  
Commercial Fishing ◽  
South American ◽  
Killer Whales ◽  
Sea Lion ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Trawl Fishery ◽  
Fishing Vessels ◽  
Almost All

Killer whale-seal interactions have been reported for almost all pinniped species globally. However the literature on offshore interactions between killer whales and sea lions is rare for the South Atlantic, particularly in Argentine waters. Here we report for the first time the harassment of a South American sea lion (Otaria flavescens) by killer whales (Ornicus orca) while attending commercial fishing vessels in offshore national waters and describe a novel sea lion antipredator behaviour. These observations were made during an ongoing survey to assess seabird-fisheries interactions in the commercial trawl fishery off Argentina.

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