Determinacion de los factores que inciden en la captura incidental de aves marinas en la flota palangrera pelagica chilena

We analized the relationship between the variability in the rate of seabird bycatch in pelagic longline fishery for swordfish ( Xiphias gladius ), and several temporary, environmental, spatial and fisheries factors for the fishing period from 2007 to 2009. The results show that the fishing operations of this fleet mainly affect the albatross, group that accounts for 83.7% of the incidental catch of seabirds recorded in the period. This bycatch is due primarily to the presence of the South Pacific Subtropical Front, a system that causes the overlap between the activities of this fleet with the spatial distribution of these seabird species during the resident phase of the nonbreeding period. By the other hand, the variability in bycatch would be strongly linked to visual stimuli (measured by the percentage of chemical lights and percentage of squid) and the existing ambient lighting conditions during the set (measured by the lag time of sunset with respect to time start set and lunar phase).