Can Similar Gear Modifications Developed to Reduce Sea Turtle Bycatch in Marine Fisheries Reduce Bycatch of At-Risk Turtles in Inland Fisheries?

Commercial fisheries bycatch, and the mortality associated with it, is of concern to conservation scientists. Much of this concern is focused on the marine realm, specifically on charismatic organisms such as sea turtles. However, freshwater fisheries also can generate bycatch, although less studied. In both the marine and freshwater realms, some fisheries have to contend with turtle bycatch issues involving at-risk species. To mitigate bycatch mortality, modifying fishing gears is a common practice in marine fisheries (e.g., bycatch reduction devices). As these modifications appear to reduce turtle bycatch, there is potential for similar modifications to be integrated into freshwater fishing gears. In an inland hoop net fishery in Ontario, freshwater turtles (including at-risk species) are encountered as bycatch and are prone to drowning. To increase survival, we tested three types of modifications that were initially developed for sea turtles; excluding turtles from entering nets, allowing turtles to escape nets, and allowing turtles the ability to reach the surface. All three modifications worked to some degree, however, the escape modification was the most successful in that it completely eliminated turtle bycatch while letting few target fish escape. Further study needs to look at the capability of the modification to work on a broad scale and with multiple turtle species. Modifications from the marine realm have the potential to be successfully implemented in freshwater fisheries to protect at-risk turtle species, but more research is needed to evaluate their efficacy.