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

Published source details Vilata J., Olivia D. & Sepulveda 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.
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This study is summarised as evidence for the following.

	Action	Category
	Use acoustic devices at aquaculture systems Action Link

Use acoustic devices at aquaculture systems

A before-and-after, site comparison study in 2007–2008 at two salmon farms in the Reloncaví fjord, Chile (Vilata et al. 2010) found that installing an acoustic device reduced the amount of Atlantic salmon Salmo salar predated by South American sea lions Otaria flavescens, and fewer salmon were predated overall compared to at a farm without a device. At one farm, lower amounts of salmon were predated by sea lions in April–June 2008 after the acoustic device was installed (total 8 tons) compared to April–June 2007 before the device was installed (total 13 tons). During April–June 2008, lower amounts of salmon were also predated at the farm with the acoustic device than at a second farm without a device (total 68 tons), where amounts of predated salmon increased during this time (from 8 to 42 tons/month). The amount of predated salmon at the two farms did not differ significantly in January–March 2008 before the device was installed (8 vs 13 tons). An acoustic device (Airmar dB Plus II with eight sound projectors) was installed at one of two salmon farms in March 2008. The device emitted 1.4 ms sounds at intervals of 40 ms and a frequency of 10.3 kHz. Data on salmon predated by sea lions in 2007–2008 were taken from each of the two farms’ logbooks.

(Summarised by: Anna Berthinussen)