July 17, 2023

 

SalMar's 'Marine Donut' for enclosed salmon farming heads to sea

Norwegian aquaculture company SalMar has taken delivery of a revolutionary enclosed aquaculture system known as the "Marine Donut," developed Norwegian aquaculture technology firm Bluegreen, which aims to transform salmon farming, SeafoodSource reported.

 

The donut-shaped fish farm is constructed using a 600-metric-tonne thermoplastics structure, making it the largest of its kind in the world. The innovative design is intended to address various challenges in salmon farming, including the prevention of salmon escapes, minimising the risk of diseases, algae, and sea lice, and reducing the need for antibiotics and medications.

 

The Marine Donut is made of high-density polyethylene and features a torus shape, serving as a protective barrier against the surrounding ocean environment. Floating pipes act as ballast to maintain the system's stability and allow for raising or submerging the cage as necessary. Inside the donut, a flow system resembling a river environment is utilized, providing exercise for the fish and ensuring optimal fish density throughout the facility.

 

Nils-Johan Tufte, chief executive officer of Bluegreem, said that while the initial production costs of the Marine Donut are higher compared to traditional net-pens, the farming efficiency of the enclosed system compensates for these costs.

 

Tufte said that the production cost per kg of salmon will be competitive due to the elimination of delousing treatments, higher fish density, reduced downtime, lower mortality, and improved feed-conversion ratio. The Marine Donut presents an exciting opportunity to validate these hypotheses.

 

The concept for the salmon farming donut originated in 2015, with Mowi, a leading Norwegian salmon farmer, initially exploring the idea. Mowi's development licenses for composite-based, closed-containment aquaculture units, including the "Egg" salmon farm, were later acquired by Bluegreen.

 

SalMar, known for its innovation in the industry, commissioned Bluegreen to bring the Marine Donut project to life in September 2022.

 

The Marine Donut has now completed its 510-nautical-mile journey from Bamble, Norway, to the Romsdal Fjord, where SalMar will introduce 200,000 salmon weighing 2.5kg each into the 22,000-cubic-meter interior of the donut. The fish will be nurtured within the enclosed system until they reach a harvest size of 5.5kg.

 

This milestone marks the beginning of the verification process to assess the Marine Donut's ability to promote fish health, deliver high-quality fish, and ensure profitability for fish farmers.

 

SalMar COO Farming Roger Bekken expressed excitement about the Marine Donut and the company's collaboration with Bluegreen, emphasising SalMar's commitment to innovation in the industry.

 

-      SeafoodSource