Illustration of what the concrete structure would look like. Drone photo: Baard Selfors. Source: Salten Aqua.

A concrete plan for salmon farming’s future

A floating, concrete salmon pen with an integrated processing facility is being developed in a joint venture between fish farmers and oil and gas industry experts in Norway.

Wenberg Fisheries and Edelfarm plan to develop a concrete structure suitable for farming in both a fjord / loch environment and the open sea. The pen would allow post-smolts to grow into fish weighing 5kg.

The companies have entered into a partnership with BioVio technologic in Bodø, and the international oil and gas technology company TechnipFMC, to tap into expertise in offshore engineering.

Geir Wenberg: Making use of offshore industry expertise. Photo: Salten Salmon

Geir Wenberg, chief executive of Salten Aqua, which is jointly owned by Wenberg, Edelfarm and aquaculture research institution Gifas, said that the cooperation was first and foremost about taking advantage of the academic resources the partner companies are sitting on.

Concrete wall and base

“Here we have both people and expertise from offshore that have not been available to aquaculture previously. They think in a slightly different way, and have a good understanding of the marine industry,” he said.

Although described as “semi-closed”, the floating, circular cage will have a concrete wall and base. The top will have an integrated a processing facility with additional features. The concept will allow full control of the water going in and out of the structure.

The construction is planned to have a capacity of 3,000 square meters, but Wenberg says that concept in this sense is modular, and the cage can be as large as required and scaled to conditions.

No lice

“The concept covers everything in relation to fish health, operations, and makes sorting and delivery to a wellboat easier than before,” he says.

The fish farmers envisage putting out smolt sized between 100 to 200 grams, where they can grow to be up to 5kg.

“The fish should be in the cage the rest of their lives and should not be out in the open cages,” says Wenberg.


He points out that in this way they will not have lice, and that concept is escape-proof.

The system has intake of seawater from different depths and temperatures. Byproduct from the device will also be separated out and used as the resource as part of the concept.

Wenberg adds that one of the aims of the project is that such a floating pen can be placed anywhere.

“It will be part of the testing we are doing now, but we think that it may be appropriate to place such a device in both fjords and unprotected waters. It is designed for harsh conditions,” he said.  

Sub-projects started

The fish farmers have applied to Norway’s Directorate of Fisheries for ten development permits – intended to allow developers to grow enough extra salmon to justify investments in new growing technology – and a biomass of 7,800 tonnes. But the queue for processing development applications is still long, with 68 applications pending at the turn of the year.

Wenberg says that they are not sitting and waiting for a response.

“We have started with several things and started several sub-projects that are appropriate for the concept,” he said.

Among other things this winter they will try out a test rig in a land-based tank in a hatchery.

“The device is very small, but it contains all the features that will be in a full-scale unit,” he said.

Published: 12/01/2018 at 9:13 am

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