Operational interaction between South American sea lions Otaria flavescens and artisanal (small-scale) fishing in Chile: Results from interview surveys and on-board observations

A longstanding competition for fishery resources has existed in Chile between the South American sea lion (Otaria flavescens) and artisanal (small-scale) fisheries. This competition is viewed as a conflict by the fishermen because sea lions prey on fish caught in their fishing gear, often causing its damage. The objective of the study was to describe the interaction between sea lions and fishermen, and to evaluate the effects of operational interference caused by sea lions on their artisanal fishery. Descriptions of the interactions cited were made during 69 observational trips on fishing vessels plus interviews of 384 fishermen. Evaluation of the interactions was based on minimum and maximum scenarios. Almost all the artisanal fishermen complained of frequent problems with sea lions, however, such interactions were observed in 14.5% of the observer trips on fishing vessels. The results showed that loss of catch due to sea lions, varied between 1.83 and 21.1% of the CPUE (under minimal) and from 1.98 to 33.8% (under maximal) interactive scenarios. Although proportions of interactive fishing events and number of sea lions were different between the locations studied, CPUE per fishing gear did not differ significantly between interactive and non-interactive fishing trips among the areas. Also, no significant relation was found between the numbers of sea lions interacting during the fishing trip and the CPUE. Our results suggest that sea lions do not produce a significant effect on variations in the CPUE obtained by artisanal fishermen. Nevertheless, these findings must be confirmed with more intensive monitoring. A cooperative design of a co-management plan, which considers biological, social, and economical features will contribute to make consensus within the stakeholders looking for management options with the aim of reducing the conflicts.