Bringing cherry salmon to the masses

J-STORIES - A Japanese startup is utilizing disused fish farms to sustainably nurture a prized species of salmon whose succulent flesh makes it a gastronome's delight.

Cherry salmon, or "sakura masu" as it is known in Japan, can be found in the waters of the North Pacific, and can grow to around 70 cm in length, or more than twice the size of regular river masu, making it a commercially sought-after species.

While it is usually served either broiled or baked, cherry salmon is difficult to prepare raw for sashimi or sushi as, in the wild, it feeds on small crustaceans called krill, which contain parasitic worms. This led Ken Ueno, CEO of the Miyazaki-based aquaculture startup, Smolt, to find a solution by farming the fish in disused tanks on land and pens in the ocean where feed can be controlled.

Ueno, who is also studying for a doctorate at the University of Miyazaki, says that he started the company in 2019 to undertake research that would benefit society, and to popularize cherry salmon, which is often associated with "posh" high-end restaurants.

The company is named after a term for young silver-colored salmon making their way to the sea.     Source: Smolt <br> — The company is named after a term for young silver-colored salmon making their way to the sea. Source: Smolt

Using a “circular” aquaculture method, fry are hatched in freshwater tanks on land, and when they reach 20 centimeters in length are transferred to ocean pens. Then, after being raised there for several months they are returned to their tanks — a process that mirrors that found in the wild, where the life cycle of salmon is divided into marine and freshwater developmental stages.

Miyazaki, a prefecture in the southern Japanese island of Kyushu, once had a thriving trout farming industry. A decline In recent years, however, has meant some freshwater farms have fallen into disuse. And while ocean pens are still employed for farming fish such as amberjack, they are empty in winter. It is these vacant farms and pens that Smolt has been using to farm its cherry salmon.

It has been widely applauded for its forward-looking approach. In 2021, the sustainability of the project was recognized with a Japan Science and Technology Agency sponsored STI for SDGs award.

Ocean sea pens for raising "sakura masu," more commonly known as cherry salmon.     Source: Smolt<br> — Ocean sea pens for raising "sakura masu," more commonly known as cherry salmon. Source: Smolt

The company's farmed salmon has been given the brand-name “Honsakuramasu” ("genuine cherry salmon") and because they are free of parasitic worms, they can be served raw as sashimi, or sushi.

Furthermore, the salmon’s krill-free diet also leads them to produce roe that is a yellowy golden color, rather than the usual red. This has been branded “Tsukimi Ikura” (moon-viewing salmon roe).

The fish and roe are sold on Smolt’s official website, as well as in department stores and from gift catalogs. The company now has its sights set on exporting to overseas markets, especially to Asian countries such as China where gold-colored products have a special cachet.

The cherry salmon roe is a yellowy golden color, rather than the usual red.     Source: Smolt. — The cherry salmon roe is a yellowy golden color, rather than the usual red. Source: Smolt.

In September, the company successfully raised funds for its future expansion, Ueno told J-Stories.

“We want to establish these products as brands, systemize our aquaculture technology, and create a company that can support producers for the future of the fishing industry.”