Seabird breeding population size on the Antarctic Peninsula related to fisheries activities in non-breeding ranges off South America

Abstract

AbstractPopulation growth of the southern giant petrelMacronectes giganteusfrom South America has been linked with an increase in fishing activities. It was demonstrated recently that a population from Elephant Island, Antarctic Peninsula, largely overlaps its non-breeding distribution with zones of high fishing intensity off South America. This study investigated the assumption that the increase in this population since the 1980s is related to an increase in fisheries off South America. Our results show that the population size is proportional to the increase in demersal and squid fisheries. These fisheries produce a considerable amount of discards, which can be used by non-breeding southern giant petrels as a food source during unfavourable conditions in winter. This may enhance the adult survival rates with potential carry-over effects on population size. Our study shows that we need to further understand the effects of fishery discards/offal on scavenging seabirds of the Southern Ocean, and highlights the importance of understanding the carry-over effects of seabird–fisheries interactions during the non-breeding phase in population dynamics.