This project will double Norway's floating closed cage production

Steel cutting for the first six Aquatraz C2 cages for salmon farming heavyweights SalMar and Lerøy is under way at a fabrication yard in China. Both SalMar and Seafarming Systems were present at the yard for the steel cutting ceremony.

The ceremony marked the start of production of a new generation of closed steel cages, which developer Seafarming Systems says is an important step in the realisation of the company's industrial commitment to closed aquaculture technology. 

“This is a significant milestone for us. Seeing the steel being cut for Aquatraz C2 confirms that we are now in a new phase, from development to industrial delivery,” said Seafarming Systems general manager Alf Reidar Sandstad. 

How Aquatraz was improved over time

The first iteration of the Aquatraz cage was delivered to Norwegian salmon farmer Mid-Norsk Havbruk (MNH) in 2018-19 by Seafarming Systems after construction at Fosen Yard, Kvithylla, in Trøndelag, central Norway. It comprised an 8-metre deep steel wall and a net below it.

Later iterations offered more protection against sea lice and have resulted in the enclosed C2, which meets new Norwegian government requirements. SalMar acquired MNH assets in 2022 after a series of mergers and acquisitions in the Norwegian salmon industry.

Below: an early iteration of Aquatraz.

Will ensure good fish welfare

Aquatraz C2 is the fifth generation of the Aquatraz family and has been further developed in close collaboration with SalMar, based on experience from previous iterations of the Aquatraz, which have between them clocked up more than over 25 years in operation since the first cage was stocked in 2018.

The C2 cage has a solid steel wall down to a depth of 12 metres, and a closed bag under that. The cage has an enclosed volume of 70,000 cubic metres, double barrier, deep water intake, and integrated sludge collection. Good fish welfare is ensured through high water exchange with record low energy consumption.

“As a technology supplier, we are completely dependent on competent industrial partners. The collaboration with SalMar and Lerøy has been crucial for the development, they have been close and have helped to ensure a good end product. We greatly appreciate the trust they show us with these deliveries,” says Sandstad.

50 cages per year

The production is taking place in collaboration with Blue Ocean Wind (BOW), which has been selected as the shipyard partner for the construction of Aquatraz C2. BOW employs 8,000 people at six yards and is primarily engaged in fabrication of offshore wind farm structures, such as jackets, monopiles and floating wind foundations. According to Seafarming Systems, the ambition is to rig the company for larger scale deliveries in the future. 

“This is not a one-off project, but the start of a long-term industrial collaboration with the shipyard. Our goal is to deliver cost-effective closed cages that contribute to sustainable growth in the aquaculture industry,” said Sandstad. 

“We chose Blue Ocean Wind as a partner because it is a modern shipyard with the capacity to handle complex constructions on a large scale. This provides security for quality and delivery precision when we eventually scale up deliveries of Aquatraz C2. We expect to be able to deliver 50 cages annually over the next few years.

“We will also enter into cooperation with Norwegian shipyards that will complete the cages in this country. Which Norwegian shipyards will complete the first six cages will be decided in the coming months.”

When the six Aquatraz C2 cages are in operation, their output will approximately double the current production in closed cages in Norway.