Interaction between southern sea lions Otaria flavescens and jack mackerel Trachurus symmetricus commercial fishery off Central Chile: a geostatistical approach

• Published in: Marine ecology. Progress series (Halstenbek) 2004-11, Vol.282, p.285-294
• Main Authors: HÜCKSTÄDT, Luis A, KRAUTZ, M. Cristina
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Fundamental and applied biological sciences. Psychology; Marine; Otaria flavescens; Sea water ecosystems; Synecology; Trachurus symmetricus
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps282285

A spatial description of the operational interaction between southern sea lions and jack mackerel fishing fleet off Central Chile is presented. The descriptive analysis showed a similar spatial trend for the number of sea lions per haul and catch per haul, both increasing in the SE direction, and decreasing in the NW direction. The number of sea lions was positively correlated with catches at intermediate distances from land, while negatively correlated with the number of fishing vessels at the greatest distance from the land. The geostatistical analyses corroborate the trends found during the descriptive analysis: 2 nuclei of high abundance of sea lions were found, which spatially overlapped 2 nuclei of high jack mackerel catches; nuclei that we proposed here as hot-spots for this interaction. Both hot-spots were located on the continental slope and over the deep ocean bed. No spatial relation was found between the number of sea lions and the number of fishing vessels. Thus, it is proposed that the area enclosed between 38-40 degree S and 74-75 degree 30'W constitutes the sector of higher interaction between the southern sea lions and jack mackerel industrial fishing fleet.