Loss and abandon of fishing gears in southern Brazil and risks of occurrence of ghost-fishing

Abstract

It was investigated the presence of lost or abandoned gears by fishing activity in the shallow waters in a region of Southern Brazil, discussing their causal agents and the type of fisheries implicated. Fishers pointed out 25 events in which gillnets were lost, attributing them to the fisheries as bottom trawling, "double†trawling and purse seining. From March to June 2008, five repeated surveys performed along six beaches found 160 netting fragments, their mesh size ranging from <5 cm (trawl net for shrimps) to 18 cm (gillnet for flatfish). All mesh sizes and twines (mono or multifilament) found at the beaches are currently used in the communities of small-scale fisheries inhabiting this region. Most of nets were linked to tree branches and other plant debris. Sometimes, nets had formed groups of different mesh sizes. It is proposed that plants can assemble lost gears, helping them to be carried out towards the beach. Registers of intact buoys show that they came from cut cables. In other events, buoys cut in linear sections as thick as a cable indicate that they were lost from operating nets. Technological and operational recommendations are presented in order to reduce both the risks of losing gears and the operational life of the lost gears.