Mitigation of freshwater turtle bycatch and mortality associated with inland commercial fyke-net fisheries.

摘要

Accidental capture and drowning in entrapment-style fishing gear is a known source of mortality for freshwater turtles. Bycatch reduction devices (BRDs) reduce accidental capture by using size, shape and behavioural differences between target and bycatch species to increase gear selectivity. Behavioural observations from arena and field trials were used to inform the development of BRDs for fyke nets. Trials were conducted in the context of a fishery with a diverse target and bycatch community that complicates BRD development. To compensate, several devices were developed. A 5 cm exclusion ring reduced captures of three turtle species by > 90% but also reduced target fish captures by > 20%. An internal escape grid reliably released smaller turtles and had no major effect on target fish retention. These BRDs can be used individually or together, depending on the community and conditions, and the development method presented can be modified for other diverse fisheries.