July 1, 2014 — There are 52 commercial fish species in waters surrounding Japan, managed as 84 stocks. Of these, the resource levels of 12 (14 percent) were high, those of 36 (43 percent) were medium, and those of 36 were low. The Pacific Ocean mackerel fishery and the Tsushima Current sardine fishery, both of which had low resource levels in 2012, recovered to the medium level in 2013.
Japan manages most species using a Total Allowable Effort (TAE) system, in which the number, size and period of operation of fishing boats, and the types of gear allowed are regulated. In comparison with other countries, Japan has set a Total Allowable Catch (TAC) for only a few species: saury, Alaska pollock, sardines, mackerel, Southern mackerel, horse mackerel, squid and snow crab.
Japan faces a challenge in preventing foreign vessels from poaching in Japanese waters. Illegal fishers often set nets without buoys to avoid detection, which then entangle the gear of Japanese fishing vessels. They also use high-performance radar to detect approaching Japanese Coast Guard vessels. While the number of inspections has increased, seizures of gear have declined, indicating that it is becoming harder to catch poachers in the act. Korean, Chinese and Taiwanese vessels are most often involved.
In recent years, extreme weather such as local heavy rains and abnormally high summer temperatures has increased. The average temperature in West Japan from June to August 2013 was the highest ever recorded, and seawater temperatures were the highest since 1985.
This has caused fish preferring warmer waters, such as Spanish mackerel, to migrate north. Bluefin tuna and yellowtail are increasingly seen in Hokkaido. Meanwhile, fish that prefer cold water, such as saury, have delayed their fall migration to Japanese waters, resulting in a shorter season.
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