By-catch of Cory’s shearwater in the commercial longline fisheries based on the Mediterranean coast and operating in East Atlantic waters: First approach to incidental catches of seabird in the area

Cory’s shearwater Calonectris diomedea is an important non target seabird species caught by the longline fleets operating in the Mediterranean Sea. At the moment no data have been published about the incidence of Spanish longline fishery in the Atlantic Ocean. In this context, the analysis of data coming from the Mediterranean based long-line fleet is a new, and important information for the conservation of Cory´s shearwater in the wintering areas of the species. The main aim of this paper was to describe the incidence of this Spanish fleet operating in the Gulf of Cadiz and Macaroneasian area on Cory’s shearwater populations. We used data recorded by an onboard observer program monitoring commercial longline fisheries. A total of 152 fishing sets were observed, and the number of seabird by-catches was only 1 birds. According to our results, the longline fishery does not represent an important threat for the conservation of Cory’s shearwater in the area, possibly because the spatial distribution of the effort do not overlap with the migratory routes and foraging areas described for the species in the literature.