Demonstration of Next-Generation Land-Based Salmon Aquaculture Combining Breeding and Electrolytic Filtration, Achieving Zero Off-Flavor and High Growth
Smolt and Verde Aqua jointly announced the final results of a demonstration project for next-generation land-based salmon aquaculture, combining Smolt's high-temperature tolerant cherry salmon seedlings and Verde Aqua's electrolytic filtration system. This groundbreaking technology achieves both zero off-flavor and high growth, contributing to sustainable aquaculture under climate change.
📋 Article Processing Timeline
- 📰 Published: May 11, 2026 at 22:00
- 🔍 Collected: May 11, 2026 at 13:31
- 🤖 AI Analyzed: May 11, 2026 at 23:25 (9h 53m after Collected)
Smolt Co., Ltd. (Headquarters: Miyazaki City, Miyazaki Prefecture, Representative Director: Ken Ueno) and Verde Aqua Co., Ltd. (Headquarters: Ichinomiya City, Aichi Prefecture, Representative Director: Hiroji Takehiro) have compiled and announced the final results of a joint demonstration experiment that began in December 2024.
This experiment verified the effectiveness of a closed Recirculating Aquaculture System (RAS) combining Smolt's "high-temperature tolerant cherry salmon seedlings (*1)", developed through over six generations of selective breeding, and Verde Aqua's patented "VA Electrolytic Filtration System (*2)".
As a result of the experiment, complete suppression of off-flavor (moldy smell) without water exchange (only replenishment water) and good feed efficiency were confirmed, demonstrating the high feasibility of a next-generation salmon aquaculture model that transcends seasonal and regional constraints.
Cherry salmon sashimi made from cherry salmon experimental fish grown after 4 months from the start of the experiment.
*1 Unlike conventional salmon that require temperatures below 18℃, this variety can grow stably at around 20℃. It is an innovative variety developed through six generations of selective breeding, adapted to global warming, and can be farmed even in warm regions.
*2 Ammonia is removed by electrolysis of seawater, stabilizing water quality and simultaneously suppressing the occurrence of pathogens through sterilization. It does not require large-scale facilities or long periods of water preparation.
## Background and Challenges
Due to climate change, seawater temperatures are rising year by year (Japan's coastal waters have risen by +1.33℃ over the past 100 years, approximately double the global average) (Source: Japan Meteorological Agency "Long-term trend of sea surface temperature (near Japan)"). (Citation: https://www.data.jma.go.jp/kaiyou/data/shindan/a_1/japan_warm/japan_warm.html) Consequently, suitable areas and periods for salmon aquaculture are shrinking annually. Due to the impact of recent climate change-induced water temperature rise, marine aquaculture in Japan faces limitations in production areas and shipping times, and even in closed land-based aquaculture (RAS), challenges such as decreased biofiltration efficiency at low temperatures and increased facility size remain.
In particular, in RAS, off-flavor caused by geosmin and 2-methylisoborneol (2-MIB) has remained a quality issue and a significant bottleneck for commercialization.
This joint experiment aimed to simultaneously solve these two challenges—"elimination of seasonal and regional constraints on salmon aquaculture" and "elimination of off-flavor"—by combining breeding technology and innovative filtration technology.
## Experiment Outline
Implementation Period
December 2024 to April 2025 (approximately 4 months)
Experiment Location
Verde Aqua Co., Ltd. Ichinomiya Lab (Ichinomiya City, Aichi Prefecture)
Experimental Fish Species
High-temperature tolerant cherry salmon seedlings (Developed by Smolt Co., Ltd.・Over 6 generations of selective breeding)
Farming System
Closed Recirculating Aquaculture System (RAS) equipped with VA Electrolytic Filtration System
Evaluation Items
Growth rate・Feed Conversion Ratio (FCR)・Survival rate・Presence of off-flavor
## Demonstration Results
Evaluation Item
Demonstration Results (This Experiment)
Farming Water Temperature
15℃
Feed Conversion Ratio (FCR)
1.3
Off-flavor
Not detected (zero moldy smell)
Survival Rate
98% (only deaths due to jumping out)
Maximum initial fish weight
220g
Maximum fish weight
1480g
Cherry salmon during the experiment.
## Key Achievements
Even in an RAS environment, Smolt's high-temperature tolerant cherry salmon maintained good growth, confirming stable cultivation regardless of season.
Through the VA Electrolytic Filtration System, off-flavor (moldy smell) caused by geosmin and 2-MIB was not detected throughout the experimental period.
Due to the characteristics of electrolysis filtration not depending on bacteria, there is no waiting time for startup during low-temperature periods, confirming the possibility of expanding to compact RAS with reduced facility scale.
High quality in meat texture and flavor evaluation was also confirmed through taste tests by personnel from both companies and sushi chefs, acquiring knowledge for market development as a premium product.
View of Verde Aqua's tank cultivating cherry salmon.
## Comments from Each Company
Ken Ueno, Representative Director, Smolt Co., Ltd.
"It has been demonstrated that our high-temperature tolerant cherry salmon, cultivated over many years, combined with Verde Aqua's innovative water treatment technology, the VA Electrolytic Filtration System, can solve the major bottlenecks in land-based aquaculture growth. This achievement is a significant milestone for Japan's land-based aquaculture industry and pioneers a new standard for sustainable salmon aquaculture in the era of climate change. We have high expectations that this model will serve as a solution for aquaculture operators both domestically and internationally in the future."
Hiroji Takehiro, Representative Director, Verde Aqua Co., Ltd.
"This was the first attempt at farming salmonids with the VA Electrolytic Filtration System, but we were able to demonstrate excellent compatibility with the seedlings bred by Smolt Co., Ltd. In addition to high growth, off-flavor was completely suppressed.
This experiment verified the effectiveness of a closed Recirculating Aquaculture System (RAS) combining Smolt's "high-temperature tolerant cherry salmon seedlings (*1)", developed through over six generations of selective breeding, and Verde Aqua's patented "VA Electrolytic Filtration System (*2)".
As a result of the experiment, complete suppression of off-flavor (moldy smell) without water exchange (only replenishment water) and good feed efficiency were confirmed, demonstrating the high feasibility of a next-generation salmon aquaculture model that transcends seasonal and regional constraints.
Cherry salmon sashimi made from cherry salmon experimental fish grown after 4 months from the start of the experiment.
*1 Unlike conventional salmon that require temperatures below 18℃, this variety can grow stably at around 20℃. It is an innovative variety developed through six generations of selective breeding, adapted to global warming, and can be farmed even in warm regions.
*2 Ammonia is removed by electrolysis of seawater, stabilizing water quality and simultaneously suppressing the occurrence of pathogens through sterilization. It does not require large-scale facilities or long periods of water preparation.
## Background and Challenges
Due to climate change, seawater temperatures are rising year by year (Japan's coastal waters have risen by +1.33℃ over the past 100 years, approximately double the global average) (Source: Japan Meteorological Agency "Long-term trend of sea surface temperature (near Japan)"). (Citation: https://www.data.jma.go.jp/kaiyou/data/shindan/a_1/japan_warm/japan_warm.html) Consequently, suitable areas and periods for salmon aquaculture are shrinking annually. Due to the impact of recent climate change-induced water temperature rise, marine aquaculture in Japan faces limitations in production areas and shipping times, and even in closed land-based aquaculture (RAS), challenges such as decreased biofiltration efficiency at low temperatures and increased facility size remain.
In particular, in RAS, off-flavor caused by geosmin and 2-methylisoborneol (2-MIB) has remained a quality issue and a significant bottleneck for commercialization.
This joint experiment aimed to simultaneously solve these two challenges—"elimination of seasonal and regional constraints on salmon aquaculture" and "elimination of off-flavor"—by combining breeding technology and innovative filtration technology.
## Experiment Outline
Implementation Period
December 2024 to April 2025 (approximately 4 months)
Experiment Location
Verde Aqua Co., Ltd. Ichinomiya Lab (Ichinomiya City, Aichi Prefecture)
Experimental Fish Species
High-temperature tolerant cherry salmon seedlings (Developed by Smolt Co., Ltd.・Over 6 generations of selective breeding)
Farming System
Closed Recirculating Aquaculture System (RAS) equipped with VA Electrolytic Filtration System
Evaluation Items
Growth rate・Feed Conversion Ratio (FCR)・Survival rate・Presence of off-flavor
## Demonstration Results
Evaluation Item
Demonstration Results (This Experiment)
Farming Water Temperature
15℃
Feed Conversion Ratio (FCR)
1.3
Off-flavor
Not detected (zero moldy smell)
Survival Rate
98% (only deaths due to jumping out)
Maximum initial fish weight
220g
Maximum fish weight
1480g
Cherry salmon during the experiment.
## Key Achievements
Even in an RAS environment, Smolt's high-temperature tolerant cherry salmon maintained good growth, confirming stable cultivation regardless of season.
Through the VA Electrolytic Filtration System, off-flavor (moldy smell) caused by geosmin and 2-MIB was not detected throughout the experimental period.
Due to the characteristics of electrolysis filtration not depending on bacteria, there is no waiting time for startup during low-temperature periods, confirming the possibility of expanding to compact RAS with reduced facility scale.
High quality in meat texture and flavor evaluation was also confirmed through taste tests by personnel from both companies and sushi chefs, acquiring knowledge for market development as a premium product.
View of Verde Aqua's tank cultivating cherry salmon.
## Comments from Each Company
Ken Ueno, Representative Director, Smolt Co., Ltd.
"It has been demonstrated that our high-temperature tolerant cherry salmon, cultivated over many years, combined with Verde Aqua's innovative water treatment technology, the VA Electrolytic Filtration System, can solve the major bottlenecks in land-based aquaculture growth. This achievement is a significant milestone for Japan's land-based aquaculture industry and pioneers a new standard for sustainable salmon aquaculture in the era of climate change. We have high expectations that this model will serve as a solution for aquaculture operators both domestically and internationally in the future."
Hiroji Takehiro, Representative Director, Verde Aqua Co., Ltd.
"This was the first attempt at farming salmonids with the VA Electrolytic Filtration System, but we were able to demonstrate excellent compatibility with the seedlings bred by Smolt Co., Ltd. In addition to high growth, off-flavor was completely suppressed.