Only six out of 19 major commercial tuna stocks are being managed to avoid overfishing and restore depleted fish populations because the majority of the stocks are not protected by well-defined RFMO harvest control rules (HCRs), according to a report published by the International Seafood Sustainability Foundation (ISSF).
An Evaluation of the Sustainability of Global Tuna Stocks Relative to Marine Stewardship Council Criteria finds that while there has been progress by RFMOs towards developing harvest strategies and implementing well-defined harvest control rules, failure to implement controls for stocks before rebuilding is required has led to an inability to meet the MSC standard’s minimum requirements on harvest control rules.
In the December 2016 version of the report, almost twice as many stocks, 11 of 19, were found to be well managed. This variance can be attributed in part to refinements made in 2017 regarding how the MSC standard assesses harvest control rules.
‘Scoring guideposts were changed and additional guidance was provided to interpret the scoring guidepost text. The objective of these changes was not to alter the standard, but to continue to improve consistency in its definition and application across the wide variety of fisheries that are seeking certification,’the report’s authors state.
The report scores the main commercial tuna stocks (bigeye, yellowfin, albacore and skipjack, but not bluefin) and each tuna RFMO (ICCAT, IATTC, WCPFC, and IOTC).
80 is a passing score, below 60 is a failing score and 60–79 would indicate a conditional pass, with the requirement that any deficiency is addressed within five years if a fishery were to become MSC-certified.
Of seven Atlantic tuna stocks, two received an overall principle-level passing score; yellowfin and& northern albacore, which ‘has recovered from biomass reductions several decades ago.’
Western Pacific skipjack, Eastern Pacific yellowfin, Eastern Pacific bigeye, and Indian Ocean skipjack all received principle-level passing scores.
In the Pacific, four stocks received overall principle-level failing scores; western yellowfin, northern albacore, southern albacore and western bigeye, which has been undergoing a steady decline since the 1970s.
In the Indian Ocean, yellowfin, bigeye and albacore all received overall principle-level failing
The report finds that yellowfin stocks in the Atlantic and Indian Oceans require rebuilding, as does Atlantic bigeye.
Mediterranean albacore and Indian Ocean yellowfin had the most failing scores on individual performance indicators, including on stock rebuilding, harvest strategies and harvest control rules and tools.
Two RFMOs, WCPFC and IATTC, received passing scores for all seven performance indicators under MSC Principle 3 which states that the fishery is subject to an effective management system that respects local, national and international laws and standards and incorporates institutional and operational frameworks that require use of the resource to be responsible and sustainable.
