IPCC = The Intergovernmental Panel on Climate Change reports that "rapid changes are occurring over a wide area of the atmosphere and oceans," and that food production such as fisheries is also adversely affected. Under these circumstances, Japan pointed out that the effects of global warming are one of the causes of the lack of fishing of saury, which is familiar to the dining table.
According to the National Sanma Stick Net Fisheries Cooperative, an industry group of sanma fishermen, 1,7910 tons of saury were landed at ports nationwide last year, the lowest since 1961, when records were kept, and only 2008% from the 34,3225 tons in 5, when there was a good catch.
At Choshi Fishing Port in Chiba Prefecture, which once recorded the number one landing in Japan, it was "zero" for the first time since 1.
Regarding this record lack of saury, the Fisheries Agency's study committee released a report stating that the "offshore of fishing grounds" is progressing due to the decrease in the number of saury themselves, the rise in seawater temperature due to global warming, and changes in tidal currents.
According to experts familiar with saury ecology, migratory saury prefers water temperatures of 1950 to 10 degrees Celsius, and has been traveling south along the Oyashio Current from August onwards to spawn and migrating along the coast of Japan from Hokkaido to Chiba Prefecture.
However, according to data from the Japan Meteorological Agency, the average sea surface temperature in the waters around Japan has risen by about 15.8 degrees Celsius in about 2022 years until 100, and since 1, warm seawater vortices called "warm water masses" have stagnated for a long time off the coast of Kushiro, causing the water temperature to rise. The route along which the saury migratory migratory route moved away from the coast of the Japan offshore.
In addition, there is a small amount of plankton that saury feeds on offshore, which makes it difficult to migrate to the coast of Japan due to the miniaturization of saury, and the increase in fishing by foreign vessels has led to a decrease in resources.
Professor Shinichi Ito of the Atmosphere and Ocean Research Institute at the University of Tokyo says, "When offshore saury occurs, spawning grounds move offshore and growth is delayed, making it difficult to migrate Japan, and saury gradually moves offshore. He points out.