Bioeconomic Losses from Overharvesting Tuna
The harvest from the world’s marine capture fisheries appears to have peaked, with substantial
overcapacity in many fisheries and ongoing creep in fishing effort that continues to erode profits.
Using a dynamic programming approach that explicitly accounts for nonlinear stock effects, we show
that in one of the world’s largest fisheries - tunas of the western and central Pacific - adopting a
biomass target maximising the discounted economic profits (BMEY) from fishing would result in a
larger biomass than current levels or traditional biological targets. The gains from stock rebuilding to
fishers alone are calculated to be in excess of $3 billion over a fifty year planning horizon. Adopting a
dynamic BMEY target coupled with incentives that would allow fishers to be the beneficiaries of stock
rebuilding offers the promise of a win-win - larger and sustainable fish stocks and more profitable
Grafton, Quentin. 2008. "Bioeconomic Losses from Overharvesting Tuna," Wellington Public Policy Seminar Series, November.
Motu code: WPS0811