New case study: testing jellyfish impacts on salmon health

Using lab-reared micro jellyfish, to assess the damage they cause to fish gills

Gill disease is one of the biggest health challenges for farmed salmon in marine environments. Tiny jellyfish and similar organisms (zooplankton) are believed to play a role, but little is know about how they interact with salmon gills.

This project set out to create a controlled lab-based ‘challenge model’ using jellyfish raised in the lab. The goal was to see if these organisms could reliably cause gill damage, allowing researchers to study the problem and test new treatments and feeds.

Over five months, the team proved that this approach is possible. They were able to produce jellyfish in the lab, transport them, and expose salmon to them under controlled conditions. While the fish showed minimal visible gill damage and no clear immune response, this is an important first step. It means the model works in principle but needs further refinement to mimic real-world conditions.

Once fully developed, this model could help scientists understand how jellyfish contribute to gill disease, test functional feeds, and evaluate new prevention methods, ultimately improving fish health and sustainability in aquaculture.

The project was led by SAC Commercial Ltd (SRUC) and the other partners were Moredun Scientific, the Marine Biological Association, University of Glasgow, and Life Diagnostics. It was funded by the UK Seafood Innovation Fund and supported by SAIC.

The full title of this project is ‘Developing a zooplankton challenge model for Atlantic salmon’.

Read the full case study