Is FAD fishing an ‘economic trap’? Effects of a seasonal closure on the IO purse-seine tuna fishery

NOTE: Manuscript has been withheld by request of the authors as it has been submitted to a peer review journal. 

The management of drifting Fish Aggregating Devices (dFADs) creates heated debates in tuna fishery management organizations striving to reduce the number of deployed floating objects. Through several econometric models and a machine learning approach, we first evaluate the consequences of three management scenarios on the catch and profit of the French purse-seine fleet operating in the Indian Ocean: 1) a half reduction in the number of authorized buoys per vessel, 2) a 72-day closure of dFAD fishing with re-allocation of effort on free schools and 3) a 72-day closure of dFAD fishing without re-allocation of effort on free schools. The results show a significant decrease of fleet profits by 7%, 10% and 18%, respectively. We hypothesize an “economic trap” of dFAD fishing caused by the dilemma between using dFADs increasingly to avoid the large yellowfin caught on free schools and, in case of reallocation towardsfree-school fishing, the catch limitation of yellowfin and bigeye tunas in the Indian Ocean. The small tuna-dependent economies are also trapped into the “dFAD system” by the macroeconomic spillover effects of a supply shortage in case of a 72-day closure. The case of Seychelles illustrates the economic loss (1% decrease in fish exports resulting in -8.8% of real GDP deviation after 7 years) incurred if the management measure is repeated from year to year.

Therefore, we invite the IOTC to:

Note the complexity of socioeconomic consequences of dFAD management measures affecting CPCs in different ways. A systematic evaluation of these consequences would help to make CMM more acceptable for all member states and converge towards a consensus.