Pacific saury, or sanma, has long been a symbol of autumn in Japan, enjoyed by families and restaurants for its distinctive flavor. However, catches of the fish have dropped sharply in recent years—from approximately 355,000 tons in 2008 to about 20,000 tons in 2021. Experts attribute this decline to climate change and rising sea temperatures. As a result, prices have increased significantly, affecting communities that traditionally rely on sanma as part of their seasonal cuisine.
In response to these challenges, Maruha Nichiro has turned to aquaculture as a means to maintain sanma populations and safeguard this aspect of Japanese food culture. In October 2023, the company began experimental research with the Fukushima Marine Science Museum. The museum has experience breeding and displaying sanma since 2000 and contributed eggs and technical knowledge to the project.
Sanma are considered difficult to raise due to their sensitivity to environmental changes and physical fragility. Outdoor net pens can expose them to additional risks such as rough seas and strong currents. Drawing on decades of aquaculture experience with other species like bluefin tuna and yellowtail, Maruha Nichiro adopted a careful approach involving close observation and gradual experimentation.
The collaboration achieved notable progress by June 2024 when farmed sanma reached over 100 grams—the standard shipping size—at commercial-scale densities. In August 2024, artificial insemination techniques were successfully used, allowing researchers to select fish for traits like faster growth and disease resistance. Work continues toward developing an “egg-to-harvest” process that would enable a stable supply regardless of wild population changes.
Controlled aquaculture environments offer additional benefits beyond supply stability. Farmed sanma can be provided outside the usual autumn season. Rearing fish from eggs in sterilized seawater with contamination-free feed eliminates concerns about parasites such as Anisakis, making raw consumption safer. This method also allows for greater control over taste and nutritional content.
Maruha Nichiro’s initiative aims not only at technological advancement but also at preserving both natural resources and cultural traditions associated with sanma consumption in Japan. The ongoing partnership with the Fukushima Marine Science Museum focuses on refining feeding, rearing, and breeding methods with the goal of achieving full egg-to-harvest production.
By demonstrating that sanma can be raised from eggs through adulthood in captivity, Maruha Nichiro is working toward a reliable supply while supporting Japan’s seasonal culinary heritage.