Trap reduced lice infestation by 44%

The technology has been tested in a controlled small-scale trial at the GIFAS aquaculture station in Gildeskål. Lice infestation was reduced by an average of 44% when the system was active. The results were statistically significant and consistent across analyses.

Attracting the lice with light

With this solution, lice are lured into traps at the cage edge using light. In the traps, the lice are killed by chlorine compounds formed through the electrolysis of seawater.

"These results show that it may be possible to reduce lice infestations with a gentle and preventative technology. At the same time, we emphasise that the findings are from small-scale trials, and that the effect needs to be further documented in commercial operations," says researcher Lars Qviller at the Norwegian Veterinary Institute.

The technology has a preventative effect by reducing the number of lice larvae in the water, without requiring handling of the fish. Analyses of selected blood parameters did not indicate increased stress or physiological strain in the fish under the tested conditions.

Must be tested in larger cages

The researchers point out that the technology needs to be tested on a larger scale, where cage spacing is greater and conditions are more variable. They also recommend more extensive investigations of physiological effects, as the analyses in this study were limited.

The Veterinary Institute has had primary responsibility for data analysis and experimental design, including design of controls and treatment setup. Idea, data collection, and laboratory work are handled by other project partners and personnel at GIFAS' research station. The product has been developed in a project funded by the Research Council of Norway as a business innovation project.