Interactions between South American sea lions Otaria flavescens (Shaw) and salmon farms in southern Chile |
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Authors: | Maritza Sepú lveda,& Doris Oliva |
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Affiliation: | Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile |
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Abstract: | By means of surveys in 48 salmon farms in Chile, and the analysis of fish mortality in 23, the results showed that attacks by the South American sea lion, Otaria flavescens, were periodical at a daily and seasonal scale, and because of their natural nocturnal feeding behaviour, were more frequent at night and in fall–winter seasons. The attacks varied markedly between the farms studied. No relation was found between the intensity of attacks, the distance to the nearest colony of sea lions and the population in the colony. Differences found between farms could be because of the different protective devices used, namely anti‐predator nets, acoustic harassment devices (AHDs) and fibreglass models of killer whales, and the way in which they were used. Of these devices, only the anti‐predator net achieved a permanent reduction in sea lion attacks. Both AHDs and fibreglass killer whales were inefficient in the short term. |
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Keywords: | South American sea lion Otaria flavescens salmon farms protection devices acoustic harassment devices anti-predator net |
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