Gillnet fisheries as a major mortality factor of Magellanic penguins in wintering areas

► Bycatch of diving seabirds in gillnets is an overlooked conservation problem. ► We recorded for the first time in Brazil incidental catches of Magellanic penguins. ► Capture rates occurred in both bottom and driftnet fisheries. ► A total of 68 penguins were killed in 16 sets. ► The impact of gillnets upon penguin populations is probably high.