Rising Sea Temperatures Impact Japan's Fisheries and Aquaculture
The surface ocean temperatures in waters near the Japanese archipelago reached a record high from June to February for the third consecutive year, negatively impacting the fisheries and aquaculture industries. This is the first time such high temperatures have been recorded since the Japan Meteorological Agency (JMA) began tracking surface sea temperatures in 1982.
In 2023, the average ocean surface temperature in waters near Japan was 1 degree higher between June and August than normal. The September-November period saw a 1.9 degree increase, and the December-February period saw a 1.1 degree increase.
The record-breaking temperatures are attributed to global warming and a shift in the direction of the Black Current, a warm current flowing from south to north. Since spring 2023, the Black Current has continued to flow along the coast of the northeastern Tohoku region, rather than traveling eastward. This unusual shift has brought a variety of fish to the Tohoku region that have not been previously caught.
The high sea temperatures are taking a toll on fisheries and aquaculture industries. Large hauls of yellowtail and blowfish have been reported in Hokkaido, while catches of cold water fish, such as salmon, have plunged in the sea off the Tohoku region. The higher water temperature is also affecting the growth of seaweed, which normally fares better in colder water.
The JMA expects the sea surface temperature to remain high this year, given the agency's forecast for this year's air temperature being as high or higher than in 2023. This could further exacerbate the challenges faced by the fisheries and aquaculture industries.