Reducing the By-catch of Platypuses (Ornithorhynchus anatinus) in Commercial and Recreational Fishing Gear in New South Wales

摘要

The problem of platypus by-catch mortality in the eel, yabby and carp trap fisheries in New South Wales is reviewed, and the results of several experiments to determine the effectiveness of gear modifications to reduce platypus by-catch are presented. Entrance screens with 50-60 mm openings prevented the entry of platypuses into eel or yabby traps. Larger screens were not effective as a deterrent to platypuses entering traps. By-catch of platypuses in the eel fishery can be minimised by restricting traps to estuarine areas, where platypuses seldom occur, and by providing air spaces in the cod ends of traps used in impoundments and farm dams. Prohibiting the use of yabby traps in areas where platypuses are known to occur provides the most practical protection against by-catch of platypuses in this fishery. Platypuses were unable to exit from prototype carp traps, designed to permit escape of air-breathing species, but the provision of appropriately-sized openings at the base of the entrance funnels in these dram traps permitted platypuses to escape.