dFADs: fisher’s friend or foe ?

Posted on 01 August 2023

Drifting fish aggregating devices, or dFADs, are floating structures used to attract fish in the open ocean so that they can then be caught en masse. Used in conjunction with purse seine nets, these devices have revolutionized commercial fishing by allowing fleets to harvest more tuna in much less time, saving money while improving yield.

However, this innovation has come at a cost. Because dFADs are not selective, a vast number of juvenile fish are caught before they can spawn. The result: except for a brief period around 2010 when piracy drove industrial fishing vessels away, tuna populations in the Indian Ocean have been in a steady decline since dFADs were first introduced in the mid-1980s.

In 2015, the Indian Ocean Tuna Commission (IOTC) declared Indian Ocean yellowfin tuna overfished. Yet until February 2023, when the IOTC adopted Resolution 23/02, this declaration had not been matched by effective measures to curb overfishing.