Aerial view of the Marine Donut in Romsdal Fjord.
Bluegreen Group.
Bluegreen Group’s innovative closed fish farming facility, the Marine Donut, has successfully completed its first full-scale test, delivering promising results, the company has announced.
The facility, a floating closed containment system which was acquired by SalMar in September 2022, is currently deployed near Molde, in Møre og Romsdal, Norway.
The facility was tested with a 101-day trial, stocked with 195,000 salmon weighing an average of 3kg. Over the trial period, critical parameters such as water quality, fish health, and technical performance were closely monitored, and the facility achieved a very low fish mortality rate of 0.8%, Bluegreen reports.
According to Geir Andresen, Chief Commercial Officer at Bluegreen, the test confirms the Marine Donut’s potential as a commercially viable solution. “This full-scale test has provided valuable data and insights that will be crucial for further development of this groundbreaking technology,” he stated in a press release.
Bluegreen reports that key findings from the test included good water quality, with stable oxygen, pH, salinity and temperature levels, despite some minor issues with water clarity measurements. On fish health and welfare, the company reports that despite the presence of pancreas disease (PD) in the population, the salmon exhibited excellent health, with assessments indicating minimal stress, good gill health, and no significant deformities or injuries. Regarding the facility's technical performance, Bluegreen reports that the water exchange system functioned effectively, with some adjustments made to optimize current speeds.
The trial was concluded at the end of October, when the facility was emptied and the fish, amounting to approximately 1,000 tonnes, were harvested through a 24-hour operation designed to minimize stress, the company reports, with oxygen levels and water flow remaining stable throughout.
"It’s a major operation when approximately 1,000 tons of fish are being delivered for the first time, so of course, we were excited. We worked for just over 24 hours, including preparations, and filled two well boats," Andresen said.
"When emptying the Marine Donut, we raise the facility by about 20% and connect it to the well boat. Then, it’s tilted by 4 degrees. This ensures good water flow and optimal conditions for the fish throughout the process. At the same time, we gradually reduce the water volume to keep the fish’s environment stable for as long as possible," Andresen added. "We chose to be extra cautious since this was the first time with full biomass. Next time, we can probably complete the operation in half the time."
Bluegreen is now preparing for the second test under its development license from the Norwegian Directorate of Fisheries.
“The results from this full-scale test, along with the insights we have gained, prove that the Marine Donut is a commercially viable product. We anticipate that the upcoming launch of the environmental flexibility scheme will quickly fill our production capacity, and we are now accepting orders on an ongoing basis," the company stated.