By Pita Ligaiula in Manila, Philippines
The Western and Central Pacific Fisheries Commission (WCPFC) is heading into a final phase on bigeye tuna, with scientists warning that major choices must be made this week to keep the region’s harvest strategy work on track.
A detailed paper from the Pacific Community’s Oceanic Fisheries Programme (SPC-OFP) laid out the critical decisions WCPFC22 must take to advance a Management Procedure (MP) for bigeye tuna — a commitment the Commission is expected to deliver by 2026.
The paper summarises several years of technical work and stresses that the Commission now needs to provide “further input… to guide future work.” It highlights six areas where WCPFC22 must make clear decisions, including the target reference point, FAD closure assumptions, output metrics, and how to handle the large share of bigeye catch taken by fisheries outside the MP’s control.
WCPFC21 previously identified three candidate target reference points (TRPs) for bigeye, all based on the 2012–2015 spawning biomass level. SPC says Commission members must now consider whether these TRPs reflect their actual management objectives — and whether they should be treated as targets or thresholds, each requiring different probabilities of achievement.
The paper also warns that bigeye tuna is a genuinely mixed fishery challenge. Only about 27 percent of total bigeye catch is taken by the tropical longline fleet — the part controlled by the MP. About 17 percent is caught in Indonesia, Philippines and Vietnam archipelagic waters, where reporting is uncertain, and catches have been increasing.
SPC is proposing “sensitivity scenarios” that test the MP’s performance under both current conditions and potential increases in catch outside the MP’s reach — including recent shifts in Indonesia’s domestic fisheries.
Another major issue is the purse-seine fishery and the role of fish aggregating device (FAD) closures. SPC’s interim analyses assume the current closure system continues, but some members want MPs tested without a FAD closure baseline. Others argue the closure period should be part of the MP itself. SPC says this is now a political decision that must be clarified by the Commission.
The Scientific Committee (SC21) earlier endorsed much of the technical approach and noted the need to integrate bigeye work with harvest strategies for yellowfin, skipjack, and South Pacific albacore. SC21 also stressed that performance indicators used for bigeye should be aligned with those for yellowfin.
But time pressure is building. The harvest strategy workplan already requires a bigeye MP in 2026, and SPC warns that the annual meeting–SC cycle leaves “limited opportunities for substantive discussion” next year.
The paper suggests WCPFC consider additional mechanisms for strategic guidance during 2026 — a point echoed strongly by WWF Japan.
Intervening for WWF, Uematsu Shuhei warned that delays on bigeye and yellowfin would have consequences.
“If Harvest Strategy with Management Procedure and Harvest Control Rules for both species agreement delay, not only it will sustainable fisheries become more distant, but also it could have negative impact on fisheries and markets in the future,” he said.
