South Korea and Japan fishing towns fight to survive as climate change heats seas

The warming oceanic climate has changed the distribution of fish, making some species difficult to catch, disrupting relevant industries that have long relied on them for a living: Fishing is a primary source of income for tens of millions across Asia.

Climate change has also been linked to some fish shrinking in size. Consequently, significant pressure is piling on those who supply the seafood that billions of people in Asia use for protein and nutrition. 

“It’s not normal for seawater temperature to change as much as air does, so a rise of 1 C impacts fish much more than it sounds,” said Tsuneo Ono of the Japan Fisheries Research and Education Agency.

Ulleung fisherman Kim, 65, wears the evidence of his vocation up and down his sinewy forearms. On his deeply tanned skin are scars from cuts he sustained from errant fishhooks and burn marks from the time a gas tank exploded on his boat.

Those wounds have healed, but the problem he now faces is potentially existential for people like him, who have depended on the now-vanishing squid for a living. South Korean fishermen hauled in 23,000 tons of squid from the country’s waters last year, well below half of the 59,000 tons caught in 2020 and just 14% of the 163,000 tons landed as recently as  2014, government data shows.

This not only leaves fishermen without an income. Ulleung, an island nearly three hours by passenger ferry from the east coast of the Korean Peninsula, faces serious questions over its viability and very identity, which has for more than a century revolved around the squid that were once abundant and still account for 94% of its seafood sales.

The Korea Institute of Ocean Science and Technology describes squid as the symbol of Ulleung and says catches serve as “a barometer” for the island’s population changes. The island is now home to about 9,000 people, just over half the 16,000 who resided there in 1990.

In the commercial areas around Ulleung's ports, walls are covered with murals depicting the squid trade. 

Clusters of businesses based on squid, such as restaurants, shops that sell dried squid and purveyors of fishing equipment, are scattered throughout the island’s small commercial center. Ulleung’s squid are consumed by local residents and tourists as a savory snack, often alongside beer and nuts, served raw and dipped in soy sauce and wasabi, or sliced into ribbons and stir-fried.

Kim Tae-soon was born on Ulleung and works at the harbor where boats come in, slicing up live catches and hanging the squid to dry on racks exposed to the sea air. She remembers her childhood as a vibrant time when the island was filled with large families. “Nowadays, there’s nothing here,” she said.  

The increasing scarcity of squid is driving up prices on the island, forcing merchants to charge more and deterring their main customers, budget-conscious holidaymakers. Dried squid on the island retail for 10,000 won (about $7.30) each. A meal of squid with rice and vegetables goes for 25,000 won, close to double what similar dishes cost elsewhere in the country. 

“They’re getting more and more expensive because they’re getting more difficult to catch,” said Park Chung-ja, the owner of a small store.

She and other small retailers throughout Ulleung have tried to diversify their wares, selling a broader range of items that also leverage the island’s reputation as a clean and isolated getaway. Many hawk taffy made from squash grown on the island, as well as seaweed and root vegetables.

Such measures provide little hope for fishermen like Kim who face dire financial prospects. Kim says it costs roughly 1 million won (close to $730) in fuel each time he goes out on a fishing trip, and the scarcity of squid means it is almost impossible to catch and sell enough to turn a profit.

Another fisherman who gave only his surname, Bang, said he has of late patroled the ocean catching conch, a shellfish that commands lower prices than squid. “Nowadays there are no squid around here, so we don’t have much choice,” he said.

Sukgeun Jung, a professor at the Department of Marine Life Science at Jeju National University who has studied environments around Ulleung, argues that the government ought to ease regulations to help fishermen adapt to the changing climate. “The government should quickly and boldly eliminate regulations such as total allowable catches ... fishing zones or minimum catch sizes, to give fishermen hope of surviving the climate crisis,” the scholar said.

Meanwhile, in Japan’s northeastern Miyagi Prefecture, home to Ishinomaki, hotter waters are dealing a death blow to hoya, or sea squirt, a unique summer seafood delicacy sometimes known as sea pineapples. Seabed cultivation of sea squirts is said to have originated in the region about 120 years ago, and the seafood has historically been a flagship product for the region.

Nearly 90% of the red, hard-skinned animals cultivated by fisherman Masao Atsumi died in the summer heat of 2023, when surface water temperatures topped 27 C, surpassing the upper survivable level of around 25 C to 26 C. 

“We don’t have anything to cultivate," Atsumi said. "It’s become extremely tough to rely on them for income.” Rising water temperatures are also impacting his current main source of income, scallops.

August sea surface temperature compared to normal year*

Atsumi and fellow fishers in the area are shifting to cultivating oysters, which can endure higher temperatures. But this comes with additional investment in equipment like ropes, which can cost over 5 million yen ($32,000) in just the first year.

“I didn’t think the situation would become this bad,” he told Nikkei Asia, "but shifting businesses can’t be helped if we want to keep making a living."

Another important change has emerged off the Miyagi coast in Sanriku Bay, one of the largest fishing grounds in the northern hemisphere – the arrival of species like the cutlass fish, which have fled from warmer habitats in southern Japanese waters.

Catches of the metallic-looking, eel-like fish in the prefecture rocketed to 506 tons in 2021, up from just one ton in 2011, according to the Miyagi Prefecture Fisheries Technology Institute. With a delicate skin, cutlass fish can be enjoyed as firm, raw sashimi or cooked into flaky yet moist, fatty meat served with lemon. 

Fisherman Seiji Abe, 41, was one of the local pioneers to adapt to the new trend, having previously cultivated the now-scarce sea squirt. The 17th generation of his family to become a fisherman, Abe sought out an acquaintance in the southern Japanese island of Kyushu to educate himself on the ways and tools to catch cutlass fish, and treat them so their appearance, taste and freshness are preserved to a standard that would allow him to command prices that match his time and effort. 

The procedures are now routine work that he carries out quietly on his vessel Eiryomaru, meaning “ship on which fishing flourishes.”

Occasionally puffing out plumes of white smoke from a cigarette, Abe drops a line and waits once he detects signs of the fish on his monitoring screen, before hauling the line back up and handing freshly caught fish to his sole crew member. The apprentice fisherman has learned to instantly stun and kill the fish with a sharp blow, while Abe then measures and packages the animal with care to retain its handsome, silvery appearance. 

“When I first started, they interested only one bidder and were sold at around 1,000 to 2,000 yen per kilogram,” Abe said. Now the fruit of 10-plus hours, as far as 24 kilometers out at sea, catches the eye of multiple bidders at Ishinomaki's fish market, selling for as much as around 6,000 yen per kilogram.

Climate change can also affect the size of fish, according to University of Tokyo professor Shin-ichi Ito. “Global warming is causing more competition for resources among fish, making them smaller,” he told Nikkei Asia.

A 2024 study Ito co-authored found that fish weight in the western North Pacific Ocean dipped in the 2010s as climate change’s warming of the ocean hindered cooler, nutrient-dense water from rising to the surface, leading to fish fighting over food. 

In Ishinomaki, generally higher water temperatures have forced farmers of coho salmon, one of five Pacific salmon species, to sacrifice fish size and ship their harvest earlier than usual to prevent them from being killed by even warmer oceans, according to Shigeki Sasaki, who oversees operations of the Ishinomaki fish market.

“The fish couldn’t be fed as much, and the average weight for coho salmon traded in the market this year shrunk to two-thirds versus usual levels. Many producers suffered a 30% to 40% loss in the value of their catch,” said the veteran who has worked in the market for about 40 years. “Everyone is thinking daily about how to respond to the changing environment and enhance the value of the catch that they have.”

Similar challenges plague the seafood processing industry of Ishinomaki.

With fish catches not being what they used to be, the merchants making products out of them are facing an identity crisis, according to Taichi Fuse, head of seafood processor Fuse Syouten in Ishinomaki.

“Fishery companies primarily brand themselves based on the type of fish they’re especially good at handling,” he told Nikkei Asia. His company, located a 15-minute walk from the fish market, takes pride in freshly processed cod, made possible due to the abundant volume of sales in the local market – before their catch declined and the company was forced to start sourcing some from Japan’s northern Hokkaido region around five years ago.

“One cannot resist the flow of nature," Fuse said, "so we must strive to make the best out of the fish we can catch, the ones in front of us. We need to be quick.” He is now developing customer channels in the hopes of profiting from cutlass fish, anticipating an increase in the years ahead.

Back at the port in Ishinomaki, in broad daylight after his long day at sea, Seiji Abe is embracing the challenge with resolve.

“I try to stay updated on information about southern fish and learn new fishing methods as much as possible so that I have alternatives to turn to whenever there’s a change in the catch,” he said.

Gloom has long since set in on Ulleung Island.

Fisherman Bang employs a crew of three workers from Sri Lanka, part of the growing numbers of migrants in South Korea filling jobs in fisheries, agriculture and manufacturing. “Nowadays no South Koreans want to do this work,” he said, speaking as his crew sat on his boat using knives to prise conches one by one from the nets used to catch them.

Late last year, the South Korean government approved up to 30 million won to individual squid fishermen as emergency assistance meant to stave off bankruptcy. Lawmakers acknowledged that the economics of squid fishing have worsened to the point where boat operators like Kim Hae-soo opt not to leave shore due to high fuel costs and meager catches.

“Nowadays most fishermen don’t bother going out to catch fish and are living off of loans,” Kim said. “We’re hungry.”