Handbooks on crowding salmon launched by Nofima

The Norwegian food research institute Nofima and the Institute of Marine Research have released two handbooks focused on measuring and monitoring the welfare of salmon during crowding – one tailored for tanks and the other for marine net pens.

Nofima salmon handbooks

Crowding is one of the most critical steps in the successful handling of farmed salmon – typically occurring when fish are moved or treated and involving temporarily increasing fish density and reducing available water volume.

Nofima explained that the purpose of the handbooks is to support fish farmers in monitoring and hopefully improving the crowding process. The authors have updated existing frameworks and toolboxes to monitor and measure welfare before, during, and after crowding. They also provide schemes and metrics for monitoring crowding above and below water and introduce the first version of a novel underwater crowding intensity risk scale designed for use by ROV operators, based upon work led by the Institute of Marine Research.

The handbooks were developed as part of the CrowdMonitor project, funded by FHF – Norwegian Seafood Research Fund. Cermaq Norway AS and Grieg Seafood ASA have also contributed valuable practical experience to the project and the handbooks.

You find the handbooks first at fhf.nohttps://www.fhf.no/prosjekter/prosjektbasen/901595/.

While the recommendations in the handbooks do not guarantee positive outcomes during crowding, they are intended to serve as guidance and support for operators performing and monitoring such procedures.

“We have received many inquiries about this from the industry in Norway and abroad, so there is clearly a need for more information,” Nofima Project Manager Chris Noble said.

Noble also encourages fish farmers to visit the project (https://nofima.no/prosjekt/crowdmonitor/) where they can find recordings of the webinar where the handbooks were presented, and soon, the handbooks, practical posters and fact sheets. The handbooks are currently available in English and will be translated into Norwegian this winter.

Together with Lars Helge Stien from the Institute of Marine Research, Noble will host a new webinar in April 2026 to gather feedback on the handbooks and release a revised version if needed.