Premium
Interactions between South American sea lions Otaria flavescens (Shaw) and salmon farms in southern Chile
Author(s) -
Sepúlveda Maritza,
Oliva Doris
Publication year - 2005
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/j.1365-2109.2005.01320.x
Subject(s) - sea lion , biology , predator , fishery , population , predation , fish <actinopterygii> , ecology , demography , sociology
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.