Utilisation of discards from small-scale fisheries by seabirds in coastal waters of Paraná State, Brazil

Abstract

Fishery discards support scavenging seabird populations in many parts of the world, but little is known of this relationship in Brazil. The present study of the coast of Paraná, southern Brazil conducted monthly surveys over twelve months. We observed nine species of scavenging seabirds taking discards, Magnificent Frigatebird Fregata magnificens and Brown Booby Sula leucogaster being the most abundant and frequent. The highest numbers of scavenging seabirds were observed during trawling activities, which provided far more discards at sea than driftnet fishing. During a fishing moratorium, when no use of trawl nets was permitted, numbers of scavenging seabirds at boats were lower. It seems likely that scavenging seabird populations of the Paraná coast benefit from this supplementary food supply, but the extent to which their numbers are affected is unknown.