Bluefin tuna fishing: International regulations led to stock recovery

Strict fishing regulations have been shown to have led to steady recovery of stocks. Japan, as a major fishing nation, is expected to play a responsible role in international fisheries management.

The international conference on the management of Pacific bluefin tuna agreed to increase the annual catch limit in response to the recovery of stocks. Japan’s catch limit for large Pacific bluefin tuna weighing 30 kilograms or more will be increased by 50% to 8,421 tonnes. The catch limit for small fish has been increased by 10% to 4,407 tonnes.

The deal will be made official at a meeting of the Western and Central Pacific Fisheries Commission (WCPFC) later this year. The quota for large fish will be increased for the first time in three years, while the quota for small fish will be increased for the first time since restrictions were introduced in 2015. The increased quotas will be implemented in 2025 or later.

Bluefin tuna is popular as an ingredient in high-quality sushi and sashimi, and Japan is its largest consumer. Increased catches are also expected to lower prices for these products.

At the last conference, Japan asked for a 2.3-fold increase in the quota for large fish and a 30% increase for small fish. However, partly because some countries took a cautious stance, Japan’s requests were not approved as proposed. It is important for Japan to provide a comprehensive explanation to gain understanding from the countries concerned about the recovery of resources.

For Japan, a country surrounded by the sea, ensuring a balance between the use and conservation of fisheries resources is a serious concern.

First, the Pacific bluefin tuna population peaked at over 100,000 tonnes in the 1960s, but by 2010 it had fallen to around 10,000 tonnes. The main reason was overfishing by the Japanese.

To rebuild the population, the WCPFC — an organization founded by Japan, the United States, South Korea, Taiwan and other countries — introduced strict fishing regulations in 2015.

The results of these efforts have become evident. The organization set a goal of restoring the population to 130,000 tons by 2034, but achieved this goal ahead of schedule, reaching about 144,000 tons in 2022. This is notable as a successful example of international fisheries regulation.

On the other hand, it is worrying that there are many fish species in waters adjacent to Japan that have suffered record low catches in recent years. Total catches of all species in Japan, including farmed fish, fell to about 30% of their peak last year. Over the past 30 years, catches of Japanese squid, saury and surumeika, have fallen by more than 90%.

Various factors have been cited as causes for the decline in catches of each species, including rising sea temperatures and changing ocean currents, as well as overfishing, mainly by fishermen from different countries, which makes it difficult to manage the stock. The effects of international regulations on saury have not yet been clearly demonstrated.

It is important to continue to study the stock situation and discuss regulations based on scientific evidence. We hope that interested countries and regions will share knowledge and develop measures for species whose catches are still weak.

(From the Yomiuri Shimbun newspaper, July 24, 2024)