Gaia Series 100: Solve the seafood puzzle!

Climate change upends Japan’s seafood industry, but innovation from ocean to table offers new hope.

As the planet heats up, the icy front lines of the Arctic reveal troubling changes with global consequences. In early August 2024, beneath the unsetting sun of Spitsbergen, a Norwegian island in the Arctic Circle, scientists from 11 countries, including Japan, gather at an observation village built in 1991. Here, warming is progressing three to four times faster than the global average.

Associate Professor Jun Uetake from Hokkaido University, returning after eight years, is visibly taken aback by the rapid transformation of the Austre Broggerbreen glacier. “This wasn't here eight years ago,” he observes, pointing at a newly exposed mountainside that was once hidden beneath ice. Meltwater streams block paths that used to be passable, their reddish hue a result of iron content from the glaciers. As Associate Professor Masaki Uchida of the National Institute of Polar Research explains, the changes not only affect ice and temperature but also shift ocean currents, influencing marine ecosystems far beyond the Arctic.

Those shifts are already impacting Japan. In Toyama Prefecture's Uozu City, November's yellowtail catch, an annual hallmark of the winter season, has failed to appear. Instead, tropical species such as pinecone fish, opaleye and dolphinfish now fill nets. “All we’re seeing now are fish that prefer warm seas,” notes a local fisher. Over the past decade, seawater temperatures around Japan have risen by 1.7 degrees Celsius, a seemingly modest change with outsized effects. “For fish, a 1-degree Celsius change is like a 10-degree Celsius shift for humans,” the narrator explains.

Local knowledge, long embedded in fish names bearing seasonal kanji like “spring” for Spanish mackerel or “snow” for cod, no longer offers reliable guidance. These strange changes, as one observer puts it, “are happening across Japan’s coasts.”

In Sanriku, Nagasaki, and Hokkaido, unexpected species have displaced traditional ones. In one fishing port in Unzen City, Nagasaki Prefecture, crews return with boatloads of Japanese sardinella — unwanted fish with no ready buyers. “We’ve got nowhere to sell, so it’s been tough,” says Chiyota Takeshita, a local fisherman. Formerly prized anchovies are scarce, rendering traditional dried niboshi production unfeasible.

Enter Nayuta Hagino, a buyer from Tokyo-based seafood innovator Foodison. Recognising the potential of the overlooked sardinella, he initiates a pilot to repurpose it into niboshi. After experimenting with broth comparisons, sardinella versus anchovy, the team finds the new variant “cleaner, more refined.” Six tonnes of sardinella are processed into dried fish, and Foodison agrees to purchase them at 500 yen per kilo, which is about eight times what the local fishery co-op offers for feed use.

Restaurants respond. At Kaibushi Noodles in Tokyo, owner Kazunari Koriyama features a limited-edition cold noodle dish using sardinella broth. “Even when chilled, there’s no bitterness or harshness. Only pure umami,” he declares. Customers are intrigued, many hearing the word “sardinella” for the first time.

Meanwhile, Kenichiro Hoshino, Foodison’s headband-wearing buyer team leader, tackles another surplus: red snow crab. When rough seas cut supplies in Hyogo’s Kami Town, Hoshino reroutes crabs from Hokkaido to underutilised processors in the region. “There is no need for new equipment,” says one plant manager. The collaboration yields a popular new product: a stuffed crab shell dish sold through Foodison’s retail arm Sakana Bacca and its e-commerce site UoPochi.

Another puzzling arrival: red trumpetfish. Once rare in Sanriku, they are now appearing regularly, though their edible portion is small at just 200 grams. Most locals had never seen them before. Enter Hidemitsu Yamamoto, affectionately known as Mr Hide, another Foodison buyer. Originally from Miyako City in Iwate Prefecture, Mr Hide lost over 10 relatives in the 2011 Great East Japan Earthquake. Now, he returns to help rebuild his hometown through seafood innovation.

Working with a Tokyo restaurant, Mr Hide helps develop grilled skewers and a trumpetfish hotpot. “It has a gentle flavour,” a customer says. The fish also finds its way into niboshi production and onto the menus of restaurants and fish classes for children. “Why are they here?” a child asks during a lesson. “Because it’s warmer,” replies the instructor.

Foodison’s work underscores a key message: the ocean is changing, but those who live by it can adapt. As President Toru Yamamoto explains, “We don’t think we just have to accept it. But within those changes, we need to find ways to create value from things we’ve overlooked.” The company's efforts reflect a broader hope, that creativity, cooperation and respect for nature can piece together the puzzle of a warming sea.

Back in Spitsbergen, Associate Professor Uchida investigates how plant life is being damaged by the earlier arrival of barnacle geese from Scotland. Due to rising temperatures, spring comes sooner in the Arctic, prompting earlier plant growth. But the geese's migration timing has not kept pace. “They notice they came too late... the ecosystem has to react,” explains Dr Maarten Loonen, a Dutch researcher who has studied the birds for 35 years. With plants already past their peak nutritional value by the time the birds arrive, both the geese and their predators, such as arctic foxes and polar bears, face cascading disruptions. 

The imbalance echoes what Japan is experiencing: climate change is not theoretical. It is transforming life and livelihoods today. Amid shifting currents, melting glaciers, and elusive yellowtail, this episode of Japan Hour offers a poignant reminder: adaptation is not just possible given the changing climate, it is imperative.