Perfect Plant for Smolt

The closed concrete fleet retrieves water from 20 meters depth, has filters on the intake water and self-produced oxygen is added as needed. Thus, the smolt will have almost ideal conditions for growth. The goal is to take the fish up to half a kilo in three months.

Managing Director of Engesund Fiskoppdrett, Svein Eivind Gilje and Project Manager for Engesund-merden, Gisle Andre Enstad ahead of the 1000 kbm large pool where about 100,000 fish will be fed up to 0.5 kg in three months. All photos: Pål Mugaas Jensen /

A new closed fish farm in the form of a concrete fleet is being transported from Stamneset in Bergen to the Ådnekvamme site in Masfjorden, north of Hordaland. In addition to modern equipment for water treatment, it has a 1000 cubic meter large pool for ingrowing of smolt. Here, the fish will meet ideal conditions for rapid growth without parasites and with stable water quality.
The goal of the company Engesund Fiskoppdrett is to take the fish from the smolt stage up to half a kilo in three months. Making use of large “postmolt” is an increasing practice and is something the company has experience with earlier. Already in 2012, they grew 70,000 fish of 400 grams.

Gisle Andre Enstad has been Engesund’s project manager and takes position as production manager when the fleet will be in operation.

“It went great and we could start slaughtering already after 11 months. That is why this concrete pen is something we have dreamed for a long time, “Gilje told

The fish from the new fleet will be scheduled every two years respectively in the locations of Duesund or Laberget. The fleet holds 1000 kbm, so with a density at the end of each production of around 50 kg / kbm, it indicates about 100 000 fish per cycle.
“We are excited about this. Experiences from others who have tried postmolt is that this is not always straightforward. This is a pioneering work. But we have good faith in our concept, he emphasizes.

Oxygen generator and storage tanks for oxygen
The concept of Engesundmerden is taken from Backe Bergen’s concrete fleets. Therefore, it is also built by the dry dock at Stamneset, now Backe Bergen is taken over by Bergen Group Sjøsterk. The fleet is funded by Innovation Norway and European Investment Found. The merd is built as a flow-through system.The water is collected from 20 meters, filtered for everything from jellyfish to lice larvae. The pump capacity is 1500 kbm / h. The water is added in one end and is collected in the other. Some of the water is oxygenated and reused, while the other is sent to 5 meters deep.

“We have no filter on the drain, but with the help of a washing robot that is cleaned daily, we get the most of the sludge. The robot will run automatically in the evening after the last feeding, says Enstad.

The merd will be supplied with land flow, but of course, have a unit on board for safety in case of a power failure. “We have counted on energy consumption. It will be about 1.35 kWh per kg of fish, which we believe is at the lower end of such production, he says.

Bernt Solheim shows the filter station for intake water.

To the project, Sterner supplies systems for pumping seawater, filtering of intake water, monitoring of water quality, oxygen production, and oxygen intake. Sterner also supplies automation and water quality control system as required, by pumping and oxygenation.

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