Fisheries Managers Should Reject Bid to Hike Quota of Pacific Bluefin Tuna
Severely depleted species needs long-term recovery strategy
When fisheries managers from across the Pacific meet in October, they should reject a proposal to increase quotas on Pacific bluefin tuna, a species that remains at risk at just 4.5% of its historic population size. The stock is still overfished and experiencing overfishing, according to the 2020 stock assessment, and this year’s advice from scientists recommends that managers take a precautionary approach to setting catch limits. Despite this, Japan has made a formal proposal to increase the quota by 20%.
The future of Pacific bluefin will be at stake at a virtual meeting of the Inter-American Tropical Tuna Commission and the Western and Central Pacific Fisheries Commission—the two bodies that share management of the stock—that begins Oct. 6. Instead of considering increases to catch limits, managers should give their full attention to upholding their 2017 commitment to develop a long-term plan that would restore the population and secure a profitable and healthy fishery into the future.
Raising quotas now would be highly premature. Separate from the commitment mentioned above, the commission agreed to a rebuilding plan in 2017 that has led to a small increase in stock size, which hit its low point of 1.7% of historic levels in 2010. However, in that plan, managers agreed to return the species to 20% of its historic size by 2034. And, although the rebuilding plan was much needed, it is only the bare minimum required to help this species.
In addition, scientists’ forecasts for Pacific bluefin’s recovery rely heavily on the hopeful assumption that the number of new bluefin entering the population each year—known as recruitment—will increase. But in the two most recent years of data, 2017-2018, signs point to a decrease in recruitment to levels that are among the lowest seen in nearly seven decades. Further, this year’s assessment is the first that does not analyze the stock trajectory if recruitment stays at current levels. For comparison, the 2018 assessment found that if current recruitment assumptions continue, there’s only a 3% chance of timely recovery. Clearly, increasing the catch limit now would undo the small gains that have been made and delay or derail any chance of Pacific bluefin’s recovery.
These shortsighted annual negotiations over quotas take time away from development of a long-term harvest strategy for this species, which managers committed to do in 2017. Last year and the year before, managers rejected other proposals to increase catches, but now they need to make good on their promise to move to more scientifically sound management.
The harvest strategy would be the way out of this cycle: Within this modern, science-based management approach, scientists and managers use a sophisticated tool called management strategy evaluation (MSE) to predict which of a suite of management scenarios would best meet managers’ short-, medium-, and long-term objectives for a species, while accounting for a range of uncertainties about the stock and fishery. Setting quotas using a harvest strategy makes management more efficient, transparent, and predictable and ultimately more effective at securing a species’ recovery.
At this year’s meeting, managers must honor their 2017 commitment by agreeing to dedicate funding and political support to the MSE and directing that initial results and an MSE workplan be presented next year to enable adoption of a harvest strategy by 2024 as agreed.
Year after year, proposals to raise the quota for Pacific bluefin threaten its recovery. With the stock on a precarious upswing, now is not the time to backtrack. Implementing a harvest strategy is the only way to ensure effective science-based management for years to come.
Grantly Galland is an officer with The Pew Charitable Trusts’ international fisheries team.