Fishery Trusts in the aquaculture zone (along the West Coast of Scotland) undertake an annual programme of monitoring juvenile sea trout in order to assess the infestation pressure of sea lice. This work (previously coordinated by RAFTS) has been going on for many years and is funded by Marine Scotland and Crown Estate Scotland, and we are grateful for their continuing support. 

The purpose of these projects is to support our members in their efforts to monitor wild sea trout for impacts arising from sea lice. The results are analysed by Marine Scotland Science and feed directly into discussions with planners, regulators and fish farming companies.

Techniques Used
A strategic programme of sweep netting has been delivered in Scotland for many years. Sweep netting is a widely used and well practised technique that enables assessment of the condition of fish caught at a defined location. The specific process of sweep netting is dependent on the characteristics of the site being fished, but involves drawing a net out from the shore using a boat. Once the net is paid out, the boat returns towards the shore and both ends of the net are drawn in so that any fish encircled by the net can be sampled.

In parallel with the established programme of sweep netting, we have also worked with Crown Estate Scotland and Marine Scotland to develop and refine techniques to monitor wild fish in an agreed and objective manner, ultimately with the objective of providing an appropriate feedback loop to fish farm management.

Fixed nets have the potential advantage of capturing a more representative sample of the local population of fish, including juvenile salmon. Wild fish swim freely in the net until released, following sampling for sea lice by researchers. The first phase of the project delivered a report on the preliminary results and a Standard Operating Procedure for the preparation and deployment of a fixed coastal fyke net for use by wild fisheries managers and other finfish farming companies. The current phase of this project is to roll out fyke net sampling across the aquaculture zone.

Grant Funding Received
These projects are funded by Marine Scotland and Crown Estate Scotland.
Sweep netting: £45,000
Fyke netting: £25,000