Southern blues: the challenge of managing by consensus to sustain an international tuna fishery

PARMA, A.M.

Seattle, USA

Conferencia; The Bevan Series on Sustainable Fisheries; 2006

University of Washington

Management of southern bluefin tuna (SBT) epitomizes some of the worst difficulties faced by regional management organizations trying to regulate international high-seas fisheries. Based on a highly-priced, long-lived, late maturing, and widely distributed temperate tuna species, the fishery expanded rapidly during the late 1950s leading to a continued decline in spawning stock biomass, now estimated at 5-12% of its unfished level. Concerned by declining catch rates, the main fishing nations Australia, Japan and New Zealand voluntarily agreed to substantially reduce catches during the 1980s, an agreement that was later formalized with the creation of the Commission for the Conservation of Southern Bluefin (CCSBT) in 1993. Further stock declines were halted, but the spawning stock did not recover and CCSBT could not control the expansion of catches by nonmembers during the 1990s. A history of highly contentious assessments, widely diverging perceptions among member countries, and a dysfunctional scientific advisory process led to management paralysis and culminated in international litigation in 1999. Differences were fueled by the contrasting economic incentives of a profitable tuna farming operation in Australia and a subsidized Japanese longline fleet operating at a loss. Year 2000 brought about new hopes, with a restructuring of the stock assessment and scientific committees, including the appointment of independent chairs and a panel of experts endowed with strong arbitration powers, and a decision by CCSBT to embark in a 3-year plan to design a rebuilding strategy for SBT. The approach involved member scientists proposing and testing different management procedures using the same simulation software and pre-agreed rules. It moved attention away from arguments about abundance estimates towards discussion of the testing protocols and major axes of uncertainty to include as hypotheses about stock status and projections into the future. With active participation of all members, a set of decision rules with adequate performance was developed and realistic management goals and trade-offs were re-evaluated in the light of the alternative projection scenarios. Scientific consensus was reached on the need to cut catches substantially to reduce short-term risks to the stock, followed by adoption of a specific decision rule that would have a high probability of stock rebuilding in the longer-term. As the Commission struggles with the recommendations and new uncertainties have been brought by recent allegations of possibly significant underreporting of historic catches, the question remains as to whether concerted management action will be possible or the fishery will continue to decline to a point of bioeconomic equilibrium.