MarWall at Bremnes Seashore: early results point the right way

Bremnes Seashore has taken MarWall into use at Gissøy site in Bømlo, Norway. The first weeks of data show low lice levels and low mortality in the MarWall pen.

Sea lice remain one of the biggest operational challenges in salmon farming. At Gissøy, Bremnes Seashore is testing a different approach. They are not only treating lice. They are changing and improving the water the fish live in.

How MarWall works

MarWall is ELDI's semi-closed pen solution. An 18 meter deep barrier, shields the salmon from the lice-rich surface water. At the same time, water from around 25 metres depth is pumped into the pen. Extra oxygen is automatically added to the water if needed. This deeper water is cooler, more stable and carries fewer lice larvae.

The result is a more controlled environment around the fish. The aim is to reduce lice exposure and give the salmon better conditions throughout production.

A systematic trial

Bremnes Seashore is running the project as a controlled comparison. Two of the pens at Gissøy are equipped with MarWall. The rest operate as before. This lets the team document the effect over time, under the same site conditions.

“It should result in fewer treatments, potentially no treatment at all, a lower feed conversion ratio, better growth, and lower mortality. ”

Eivind Sæverud - Head of Technical Operations and Projects, Bremnes Seashore.

The first months of operation show lower lice levels and lower mortality in the MarWall pen than in the conventional pens on the same site. So far, there has been no need for delousing at Gissøy.

The dataset is still limited, and both Bremnes Seashore and ELDI are clear on that point. Lasting improvements take time to prove, and they should be proven at full scale. The early signals are promising.

Built together

The best solutions come from farmers, suppliers and specialists working on the same problem. At Gissøy, operational staff from Bremnes Seashore and the ELDI team follow the trial closely, share what they learn and adjust along the way.

“We have to believe in this, because this is the future. ”

Martin Haldorsen, Operations Technician, Bremnes Seashore