New salmon pen concept launched to combat sea lice

Northern Lights Salmon and Sørrollnesfisk are launching together with AKVA group Egersund Net and Framo OptiCage, a new pen concept against salmon lice.

'We have adopted a special net from AKVA group Egersund Net on the pens. With a spaghetti net with a custom-made lice skirt, where the skirt is attached both at the top and bottom of the net, we can go down to a full 15 metres with a lice skirt without experiencing too much deformation,' says Christian Balteskard, Project Manager for Northern Lights Salmon and Sørrollnesfisk.

The battle against lice preoccupies most people in the fish farming industry. For the first time, the lice skirts can be lowered to 15 metres to block the lice out, while pumps bring up fresh, oxygen-rich seawater from the depths.

Utilises existing infrastructure
'It is important to look for solutions that are close at hand, and to utilise existing infrastructure for sustainable results. We have looked at how we can make "simple" changes to adapt and optimise the conditions for the fish. In OptiCage, we have assembled the most optimal solution,' says Mr Balteskard.

In the development, the fish farmers together with AKVA group Egersund Net and Framo have looked at how experience and expertise with almost standard products can be used to optimise pen conditions. The testing of the technology is supported by Innovation Norway's Environmental Technology Scheme.

'The project started in October 2021 and was completed in March 2022. This is an exciting product that means a lot to the concept of deep farming. OptiCage is helping to combat the biggest challenge the fishing industry faces, namely salmon lice. When fresh water is constantly pumped in, this gives the salmon better fish health and reduces mortality,' says Senior Sales Manager Net Products, Geir Kåre Tønnessen, in AKVA group Egersund Net.

Deeper conditions
OptiCage is to be used in six 160-metre pens from NOFI at the Ystevika site in Sør-Troms, Norway. There are already salmon in the first four, and the start-up has been very successful.

The goal of OptiCage is to use existing equipment to create a concept against salmon lice that can be used at many of today's food fish locations. In the design phase, much of the focus has been on finding practical solutions to ensure simple assembly and safe operation. In addition to protecting against salmon lice, the salmon must have good growth and living conditions throughout the cage.

98-minute change of seawater
Framo has used 50 years of pumping expertise from shipping and offshore to help produce sustainable salmon. Together with fish farmers, Framo has worked purposefully to optimise the flow conditions. The powerful water improver Framo AquaStream retrieves fresh seawater at the right temperature from deep below the lice belt. Within 98 minutes, Framo AquaStream has replaced all the water inside the skirt in the pens.

'We have adapted our Framo AquaStream system to verify the technology together with the form-fitting skirt. After successful installation and commissioning, the facility is now in operation with great success,' says Sales Manager Terje Ljones at Framo Innovation.

This ensures that the fish constantly get oxygen-rich water.

'The pumps from Framo create currents in the pen which help to recreate the natural conditions the fish experience out in the sea. The pumps can be run up and down in capacity, and the amount of water moved can thus be adapted to the biomass that is in the pen at any given time,' says Mr Ljones.

The Aquaculturists

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