Environment Climate change decimates Japanese salmon populations

[thomas]

Researchers have stated that global warming disrupts fishing conditions and threatens salmon, Japan's seafood staple. They have cautioned that climate change is pushing Hokkaido 's chum salmon, which account for most of Japan's salmon catch, into fierce competition with a related species for food, making it harder for them to return to their spawning rivers.

Kaeriyama Masahide, a salmon ecology specialist and professor emeritus at Hokkaido University, warned that if this pattern persists, Japan may lose its salmon population within the next century. Data from the Hokkaido government shows salmon numbers peaked at 56.47 million in 2003 but have since plunged to 15.62 million in 2024 — the second-lowest figure since 1989. This sustained drop has forced seafood seller Maruichi Suisan to raise the price of its "Sake Toba" salmon jerky by 20% this winter. Shop manager Numahata Kei at Sapporo's Nijo Fish Market, a lively hub for tourists and locals alike, lamented that they held prices steady for over a decade, but with dwindling catches, they had no other option.

Japan's salmon fishing industry, a key driver of the country's food culture, peaked in the 1990s and 2000s as artificial hatching and release programs expanded. Juvenile salmon, or fry, released in Hokkaido and the northeastern Tohoku region head out to sea in spring, staying in coastal waters until summer. In fall, they migrate north through the Sea of Okhotsk, the Bering Sea and the Gulf of Alaska, where they grow and migrate seasonally before returning to Japan after about four years. But a crack has emerged in this cycle. According to Kaeriyama, pink salmon, which thrive in colder waters, are rapidly increasing in the Bering Sea in the northern Pacific Ocean due to rising sea temperatures caused by global warming. Because pink salmon feed on the same nutrient-rich zooplankton as chum salmon, intense competition has ensued, with chum salmon losing the battle for food and struggling to grow, leading to their decline, he said. With fewer salmon returning to Japan, securing eggs for artificial hatching has been difficult. An association to promote the breeding of salmon and freshwater trout in Iwate Prefecture in northeastern Japan had received about 40 million of the 60 million eggs hatched in fiscal 2023 from Hokkaido, but due to a shortage of eggs in Hokkaido, the association said it had received none this fiscal year.

https://english.kyodonews.net/news/2025/02/9a00e88dc972-feature-japanese-salmon-catches-plummet-in-losing-battle-to-climate-change.html


Meanwhile, Japan is looking increasingly at releasing artificially bred salmon into local rivers:

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人工ふ化のサケ稚魚放流はじまる「一匹でも多く帰ってきて」不漁で稚魚は昨シーズンの2割に　宮城・気仙沼市（tbc東北放送） - Yahoo!ニュース

気仙沼市本吉町のサケのふ化場では、2024年の秋に捕獲したサケの卵から人工ふ化した稚魚が体長6センチほどに育っています。25日は、生産組合の人たちが稚魚をトラックのいけすに移しました。そして南気仙沼

news.yahoo.co.jp

「大不漁で大変苦戦」サケの稚魚 放流始まる、昨シーズンの2割に減（宮城・気仙沼市の大川）（2025年2月25日掲載）｜ミヤテレNEWS NNN

宮城・気仙沼市の大川では、今シーズンのサケの稚魚の放流が始まりました。 不漁により、放流は昨シーズンの2割程度になるということです。

news.ntv.co.jp