The researchers behind the sea lice compendium have travelled all around Norway and gathered knowledge on best practices from farmers and suppliers. PHOTO: NOFIMA

Project Year 2017

Best practice against lice

 Production biology  

The best way to keep sea lice at bay is to use proven methods, avoid handling and allocate enough people and time.

Through the MEDFRI project, tips and advice have been collected in a compendium that is primarily aimed at fish farmers and suppliers of methods.

“The compendium facilitates choices that are good for the fish and the farmer alike and bad for the lice,” says project manager Åsa Espmark at Nofima.

Without medications

In the period January to April 2017, scientists reviewed the most widely used, non-medicinal methods of fighting sea lice. They gathered scientific evidence, and fish farmers and method suppliers shared their valuable experience. This knowledge has been now compiled into a “best practice compendium”. Best practice means effective methods that do not negatively impact salmon welfare. Cost has also been taken into account, where possible.

The scientists have assessed non-medicinal methods, both with and without handling, preventive technological and biological measures, and combinations of methods.

The main conclusion is that methods involving handling of fish are more likely to result in injury and poor welfare. Degree of documentation of the methods varies greatly. The compendium also provides relatively detailed advice about the use of the individual methods.

Enough people and time

Espmark wants the compendium to raise the users’ awareness about non-medicinal lice control:

“Breeders must use proven methods and be dedicated to the task. They have to learn how to use the methods properly and set aside enough people and time,” says Espmark.

Not least, the suppliers of mechanical lice control methods must provide neutral documentation of the methods.

“Non-medicinal sea lice control methods are in continuous development, and hopefully we will see further improvements now we have identified a number of shortcomings,” Espmark concludes.

The Norwegian Veterinary Institute, the University of Stirling

The Fishery and Aquaculture Industry Research Fund (FHF)

More useful research results