Abstract

This work provides the first direct, at-sea monitoring of small cetacean interactions with Peruvian artisanal drift gillnet and longline vessels. A total of 253 small cetaceans were observed captured during 66 fishing trips (480 sets) monitored from March 2005-July 2007 in the port of Salaverry, northern Peru. Interactions consisted of 231 animals caught in gillnets, 1 in a longline and 21 direct takes by harpooning for use as bait. The most commonly captured species were long-beaked common dolphins Delphinus capensis, dusky dolphins Lagenorhynchus obscurus, common bottlenose dolphins Tursiops truncatus (offshore stock) and Burmeister’s porpoises Phocoena spinipinnis. Overall bycatch CPUE (catch per unit effort) was estimated to be 0.677 animals/set and 0.007 animals/set for gillnet and longline vessels, respectively. Based upon total fishing effort for the port, we estimated the average of small cetacean bycatch at 2,623 animals/year (CI 2,061-3,185) for 2002-2007. This work indicates that, in at least one Peruvian port, bycatch and harpooning of small cetaceans persist at high levels and on a regular basis, particularly in driftnet vessels. The formerly unknown practice of at-sea discarding of carcasses stands in sharp contrast with current, high small cetacean discard rates (49%) found in this study. That, combined with high prices/lack of availability of traditional bait fish suggest that small cetacean bycatch and harpooning could now potentially be reduced through the implementation of bycatch mitigation measures and greater accessibility to preferred bait.