Progress on the adoption of non-entangling drifting fish aggregating devices in tuna purse seine fleets

Up to recently drifting fish aggregation device (DFAD) designs usually had a structure built with a floating component covered with net and an underwater appendage with open net panels. Unintentional mortality though entanglement in DFADs has been observed mainly for oceanic silky sharks (Carcharhinus falciformis), and to a lower degree turtles. In recent years, scientists and fishers from key tuna purse seiner fleets have been collaborating to design DFADs minimizing entanglement. In addition, all except one tuna regional marine fisheries organization (RMFO) have guidelines for non-entangling (NE) DFADs. This paper describes the adoption of entanglement-reducing DFADs by several key fleets through skipper workshops sponsored by ISSF. At present, progress with DFADs that prevent entanglement appears to be highest in the Indian and Atlantic Ocean, medium in the Eastern Pacific and lowest in the Western and Central Pacific. The acceptance degree of NE FADs by fishers and ship-owners has been gradually increasing since 2010 and especially after learning how some fleets (e.g. European Union) have moved almost entirely to 100% NE FADs without adverse effects on their catches of tuna.