Additional reporting by Bonnie Waycott

Most seafood industry executives and Undercurrent News' own research identify Japan's Maruha Nichiro as the behemoth that sits atop the ranking of the world’s largest seafood companies. Outside of the seafood industry, the company is little known. 

The Tokyo-based Maruha Nichiro plans to change that, with farmed tuna. The company began experimenting with full egg-to-harvest in 1987 to evolve from a technique known as ranching, where young bluefin are captured in the wild and fed until they reach harvest weight. 

Maruha Nichiro has passed a number of milestones since then and has spent several years without achieving demonstrable results in farming the fish that can grow up to one meter in length and can sell for hundreds of thousands of dollars in Japanese fish markets.  

The company faces the long-term challenge of declining fish consumption in Japan, combined with a dramatic decline in the wild capture of all tuna stocks with highly prized bluefin chief among them. What started as a scientific experiment to save bluefin tuna from extinction could become a significant business unit for Maruha Nichiro in the coming years. 

“It may well become impossible to procure bluefin from the wild,” Takahisa Ookado, assistant manager of fresh fish sales for Maruha Nichiro’s aquaculture operations department, told Undercurrent News. “The closed-cycle concept is a necessity but addressing the various challenges it brings will take some time.” 

Bluefin tuna aquaculture is a rapidly growing industry, surging 70% to 59,000 metric tons in 2018, from 34,520t in 2003, according to Kindai University. Most of that was down to ranching techniques, with closed-cycle aquaculture only accounting for 6.5% for the farming total. 

Maruha Nichiro plans for a fifth of its bluefin sales to be from closed-cycle aquaculture by 2021, said company spokesman Hiroyuki Metoki. It has a longer-term ambition to be 100% closed cycle as it masters the techniques of egg-to-farm harvesting aquaculture, he said. The company sold 66,000 bluefin in 2017, of which 5,000 came from closed-cycle farming. That number fell in 2018 and 2019 because of typhoons. Maruha Nichiro, like other aquaculture firms in the Far East, is looking to use submersible cage technology to overcome the damage sustained by typhoons. 

Maruha Nichiro is also growing yellowtail in Japanese waters and more recently started to grow steelhead trout. With the latter, the company employed aquaculture tech startup Umitron to speed up grow-out periods and avoid excessively hot ocean temperatures during summer months for the cold-water species [...]