Summary
The study tested the use of glass and plastic drink bottles as low-cost bycatch mitigation devices (mechanical pingers and acoustic reflectors, respectively) in gillnet fisheries across three regions/fisheries: surface-set driftnet fisheries in Zanzibar and Peru and bottom-set trammel net fisheries in Brazil. In Brazil, plastic bottles reduced dolphin bycatch while increasing fish catch, although further trials are needed. In Peru, glass bottles had no effect on dolphin, porpoise, or turtle bycatch but altered target elasmobranch and teleost catches; plastic bottles similarly had no effect on dolphin bycatch but increased shark catch. In Zanzibar, no dolphin bycatch was recorded in any sets, though plastic bottles increased tuna catch.