The Western and Central Pacific Fisheries Commission (WCPFC) and the Inter-American Tropical Tuna Commission (IATTC) – two regional fishery management organizations (RFMOs) that set rules for tuna fishing in the Pacific Ocean – have rejected a Japanese proposal to speed up catch limit increases of Pacific bluefin tuna.
The Japanese delegation that attended a meeting of the Joint Working Group on Pacific Bluefin Tuna from 3 to 5 July in Fukuoka, Japan requested hastened catch limit increases in response to the species’ rapidly growing stock, referencing data that buttresses their claim.
A report by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean states that the initial target – jointly adopted by the WCPFC and the IATTC – of rebuilding Pacific bluefin tuna stock back up from its historically low spawning stock biomass (SSB) in 2010 was achieved in 2019 – five years earlier than expected.
A second target of limiting fishing mortality to 20 percent of the potential SSB has a 60 percent probability of success in 2023 – six years earlier than originally estimated.
“[The] WCPFC and IATTC increased the catch limits of large Pacific bluefin (30 kilograms or larger) by 15 percent since 2022, but this increase has apparently fallen behind the rapid increase of the PBF stock,” the delegation’s proposal states.
The delegation attributed the rapid increase in the population of bluefin to stricter limits imposed on retaining juveniles, which allows more fish to reach spawning size.
It also noted that as bluefin populations increase, the requirement to release bycatch bluefin from nets before hauling them in results in the escape of target fish, placing a heavy burden on fishermen – particularly those operating set-nets.
“In usual cases, fishermen release Pacific bluefin by sagging or opening a part of [their] set-net, which results in the escape of other fish species, causing great economic losses,” the report said. “Such releases are becoming more frequent all over Japan due to the significant gap between the growing stock level and the fixed catch limits. In some set net sites in Japan, fishermen released Pacific bluefin from their nets in more than half of their annual operations.”
Both longline and artisanal troll fishery vessels must shift target species after reaching their Pacific bluefin catch limit, according to the proposal’s outline of the issue. Pacific bluefin is, thus, a “choke species” that prevents fishing for other species for fear of exceeding catch limits through accidental bycatch.
Some experts said that, although the RFMOs rejected the proposal this time, there may be ...
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