scholarly journals South American sea lion and spiny dogfish predation on artisanal catches of southern hake in fjords of Chilean Patagonia

2009 ◽  
Vol 67 (2) ◽  
pp. 294-303 ◽  
Author(s):  
Ana de la Torriente ◽  
Renato A. Quiñones ◽  
Diego A. Miranda-Urbina ◽  
Fidel Echevarría
Keyword(s):  
Significant Relationship ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
South American ◽  
Southern Chile ◽  
Sea Lion ◽  
South American Sea Lion ◽  
Chilean Patagonia ◽  
Hake Fishery ◽  
Made In

Abstract de la Torriente, A., Quiñones, R. A., Miranda-Urbina, D. A., and Echevarría, F. 2010. South American sea lion and spiny dogfish predation on artisanal catches of southern hake in fjords of Chilean Patagonia. – ICES Journal of Marine Science, 67: 294–303. The South American sea lion (Otaria flavescens) is a pinniped known to interact with fisheries, potentially damaging gear and lowering catches. Predation by O. flavescens and spiny dogfish (Squalus acanthias) on artisanal southern hake (Merluccius australis) catches in fjords of Chilean Patagonia is estimated and compared. Observations were made in the Gulf of Ancud and Comau Fjord in southern Chile from October 2005 to September 2006. Losses of southern hake catches to O. flavescens predation were 1.6% of the total catch of the species, and to spiny dogfish predation were slightly higher, at 3.3%. The predation of both species on southern hake catches varied throughout the year, but was lower in summer. Both predators showed a preference for adult southern hake over juveniles. There was no significant relationship between predation on southern hake catches by the sea lion and the availability of adult and juvenile southern hake on longlines (AHCL). However, there was a significant relationship (p < 0.05) between AHCL and spiny dogfish predation. Most O. flavescens interaction events (81.4%) were during longline retrieval. Our results showed minimal interactions between O. flavescens and the artisanal southern hake fishery in the area, so with the present abundance of O. flavescens, there is no justification for reducing the sea lion population by hunting.

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.

South American Sea Lion

2009 ◽  
pp. 1076-1079 ◽  
Author(s):  
Humberto Luis Cappozzo ◽  
William F. Perrin
Keyword(s):  
South American ◽  
Sea Lion ◽  
South American Sea Lion

Reference Intervals of Mineral Elements in Plasma of Anesthetized Free-Ranging Adult Females of South American Sea Lion, Otaria flavescens

2016 ◽  
Vol 174 (2) ◽  
pp. 325-327
Author(s):  
Paula S. Polizzi ◽  
L. N. Chiodi Boudet ◽  
A. Ponce de León ◽  
M. Quiroga ◽  
D. H. Rodríguez ◽  
...  
Keyword(s):  
Mineral Elements ◽  
Reference Intervals ◽  
South American ◽  
Sea Lion ◽  
Otaria Flavescens ◽  
South American Sea Lion ◽  
Adult Females ◽  
Free Ranging

Stable isotopes of oxygen reveal dispersal patterns of the South American sea lion in the southwestern Atlantic Ocean

2013 ◽  
Vol 291 (2) ◽  
pp. 119-126 ◽  
Author(s):  
L. Zenteno ◽  
E. Crespo ◽  
N. Goodall ◽  
A. Aguilar ◽  
L. de Oliveira ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Atlantic Ocean ◽  
South American ◽  
Southwestern Atlantic ◽  
The South ◽  
Sea Lion ◽  
Dispersal Patterns ◽  
South American Sea Lion ◽  
Southwestern Atlantic Ocean

Estimated population size of two South American sea lion male haulouts from the northern coast of Argentina

Mammalia ◽  
2017 ◽  
Vol 81 (2) ◽  
Author(s):  
Gisela Giardino ◽  
Julián Bastida ◽  
M. Agustina Mandiola ◽  
Ricardo Bastida ◽  
Diego Rodríguez
Keyword(s):  
Population Size ◽  
Wild Population ◽  
South American ◽  
Northern Coast ◽  
Sea Lion ◽  
South American Sea Lion ◽  
Conservation Measures ◽  
Real Size ◽  
Direct Counting ◽  
Management And Conservation

AbstractKnowledge of the real size of any wild population is an essential tool to take management and conservation measures and even more so when the population studied may have potential conflicts with humans. Because of this, the objective of this study was to estimate the population size of two South American sea lion male haul-outs using mark-resighting techniques. The results showed that on average, the estimated total number of animals tripled the number of animals recorded by direct counting. These findings demonstrate that it is necessary to continue researching population estimate methods to apply when taking conservation measures in the future.

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