In a remarkable development for aquaculture, Smolt, a company based in Japan’s Miyazaki Prefecture, has successfully cultivated cherry salmon weighing 4 kilograms—an impressive achievement considering that farmed cherry salmon typically weigh between 1.5 to 2 kilograms at harvest.

Innovative Breeding Techniques

This milestone comes after three years of using a selectively bred strain that is heat-tolerant, alongside an all-female triploid system. The high-temperature-resistant juveniles of cherry salmon have been developed through six generations of careful selective breeding.

These specially bred juveniles thrive at approximately 20°C, while conventional salmon require water temperatures below 18°C. The all-female triploid technology further aids in suppressing sexual maturation, allowing the fish to redirect their energy from reproduction to growth. This leads to prolonged development periods and ultimately, larger sizes.

Addressing Climate Challenges

This groundbreaking advancement comes in the wake of critical challenges posed by climate change. Rising sea temperatures threaten salmon aquaculture globally, making Smolt’s innovations essential. According to the Japan Meteorological Agency, sea surface temperatures near Japan have risen by 1.33°C per century—nearly double the global average. This trend has drastically reduced suitable farming areas for cold-water salmon and increased the risk of heat-related mortality, especially during hotter months.

As a result, technologies that ensure consistent salmon production under warming conditions have become a top priority for farmers worldwide. Smolt’s advancements may serve as models for future climate-resilient aquaculture practices.

The Economic Impact

Cultivating larger sizes of cherry salmon not only has environmental benefits but economic implications as well. Enhanced sizes can bolster the competitiveness of Japan’s farmed salmon industry both domestically and internationally. Larger cherry salmon are more suited for high-end restaurants and specialty markets, offering greater opportunities.

“Cherry salmon are more difficult to grow to large sizes compared to other varieties commonly seen in the market, such as Atlantic salmon or trout. However, their flavor is exceptional. Our aim is to optimize the cultivation period for mass production, establishing cherry salmon as a globally recognized delicacy,” remarked Smolt CEO Ken Ueno.

Sustainability and Future Prospects

The impact of Smolt’s innovations stretches beyond mere size and market value; it touches on broader sustainability issues as well. With rising ocean temperatures presenting long-term challenges, the ability to cultivate salmon reliably in warmer waters lays the groundwork for future industry resilience.

Additionally, the technology enables efficient salmon roe production through an all-female population, facilitating large-scale roe harvesting.