Summary
Cory's shearwater, Calonectris diomedea, is the main seabird species incidentally caught by the Spanish longline fleet in the western Mediterranean Sea. The authors used onboard observer data to model the longline bycatch of Cory's shearwaters as a function of time of the year, technical characteristics of the fishing operation, and geographical location. The most explanatory factor for bycatch was the geographical location and then the technical characteristics (number of hooks and fishing during non-working days). Seabirds are more likely to approach longline vessels when trawlers are not allowed to operate (non-working days), so the authors conclude that activity of longliners should be limited to working days.