Fishers and seabirds competing for the same fish: Foraging strategies, interactions and consequences

Abstract

Using data from Vessel Monitoring System (VMS) and seabird electronic tracking, we analyze the interactions between the fishing activity and the foraging of breeding seabirds. We show that seabirds are able to cope with the competition with the fishery to a certain extent, foraging farther or longer. Still, breeding seabirds face at the same time high energetic demands to feed the chicks and limited foraging ranges in time and space because of the need to attend the nest. To optimize seabird breeding success, we recommend: (1) to estimate with trophic models, the adequate quantity of anchovy to reserve for seabirds; (2) to establish temporary closed areas to fishing around main breeding colonies. Maximum foraging ranges observed for guanay and booby suggest a radius of 50 to 100 km for those closed areas that would secure the foraging of those species when breeding, and then favor their population sustainability.