Promoting selective fisheries through certification? An analysis of the PNA unassociated-sets purse seine fishery

The certification by the Marine Stewardship Council of the unassociated-sets purse seine fishery of the Parties to the Nauru Agreement (PNA) has the potential to improve stocks of the fishery's main three tuna species, as well as to allow the PNA to extract more resource rents from the fishery. In this paper we analyze the economic and biological effects of this certification with a tractable bioeconomic model. We find that under plausible assumptions certification of tuna from the PNA unassociated-sets purse seine fishery can enhance stock size of skipjack tuna and bigeye tuna, but is likely to reduce stocks of yellowfin tuna due to the unassociated-sets fishery's high catch rate for this stock. The PNA's access fee declines in most scenarios considered.