Japan Govt Eyes Catch Reviews as Seawater Temps Impact Fishery Operations

Yomiuri Shimbun file photo
The Forestry and Fisheries Ministry building in Chiyoda Ward, Tokyo.

The Fisheries Agency is mulling budgetary measures and systems to encourage fishery operators to review catch targets and shift their focus to aquaculture in light of environmental changes engendered by rising water temperatures in the seas around the nation.

The nation’s fish catch totals have declined. Hokkaido has registered the largest hauls in the past few years, in terms of pufferfish, which previously were caught mainly in the Seto Inland Sea and waters off western Japan.

According to an expert panel of the agency, water temperatures in the seas around Japan rose 1.24 C over the 100-year period to 2022, topping the global average of 0.6 C for the same period. The rise in seawater temperatures is believed to have had a significant impact on fish species that live near the water surface.

Domestic catches of hairtail, formerly landed mainly in the Seto Inland Sea, have dropped in recent years, too. However, hauls have grown in scope in the Tohoku region. Juvenile hairtail have been observed in Sendai Bay, and there are signs that the fish’s spawning area has expanded northward. Similarly, blue swimming crabs’ habitats also appear to be moving northward.

Japanese pilchard habitats — previously concentrated in waters off western Japan, including the Sanin region — have spread to the northern Pacific, and catches of the fish have increased on the Pacific side since 2010. Catches of yellowtail, too, have risen in Hokkaido and other areas since the 1990s. This is likely attributable to increased numbers of the fish overwintering in northern Japan as a result of rising seawater temperatures.

Meanwhile, Japan’s total fish catch for 2021 stood at 3.191 million tons, down 522,000 tons from 2014. In particular, catches of saury (sanma), Japanese flying squid and salmon have plummeted by about 80% to 108,000 tons from 548,000 tons in 2014.

In light of such circumstances, the agency’s expert panel drew up a set of proposals in June, which included calls for increasing the number of catch target species depending on the sea area and encouraging fishery operators to shift their business to aquaculture.

The agency panel has said that ports in many areas lack processing capacity to handle new fish varieties, and that strategies are needed to increase the market value of fish that can be caught.

In the future, the agency intends to consider specific measures, including one for human resource development.