New model will show salmon farms’ impact

A consortium of research organisations in Scotland is developing what is hoped will be a more accurate way of predicting how salmon farms interact with their surrounding environment.

The new model is intended to help inform decisions on future farm locations and the development of existing farms, and to enhance the sector’s overall sustainability.

The Scottish Government has promised reform of the licensing system for salmon farms and a new “spatially-based risk assessment framework” for Scotland is currently being developed, so clarity regarding the impact of salmon farms will be critical.

The Scottish Association for Marine Science (SAMS), Scottish Salmon Producers Organisation (SSPO), Sustainable Aquaculture Innovation Centre (SAIC), and the University of Dundee are exploring how the model used to understand the interaction between fish farms and the seabed beneath them – known as NewDEPOMOD – can better reflect the physical and ecological conditions in different parts of Scotland.

The project builds on the work undertaken over the last two years by SAMS, SSPO, and SAIC – in consultation with SEPA, the Scottish environmental regulator – with the addition of expertise in environmental fluid mechanics and sediment transport dynamics from the University of Dundee.

Conducting a series of tests at their state-of-the-art laboratory facilities, researchers at the university will mimic the hydrodynamic conditions and sediment bed characteristics in different types of waters in Scotland – from sheltered sea lochs to more exposed coastal waters with rocky, sandy, or muddy seabeds. They will then model the settling, deposition, and resuspension of waste matter from fish farms to see how they will react within these environments.

Leading the way

Helena Reinardy, teaching fellow and researcher at SAMS, said: “Scotland is leading the way in developing NewDEPOMOD, creating a model that is more tailored to the conditions at sites across the country. The first phase of this project set the foundations for defining the parameters that inform decisions about fish farms locations, and this next phase will progress that even further with the addition of the University of Dundee. Ultimately, we want to create an interface between the sector and regulators that is not only useful for them both, but informed by the best science available too.”

Alan Cuthbertson, senior lecturer in environmental fluid mechanics at the University of Dundee, said: “We’re looking to help create a model that will deliver better predictions about the dispersal and settling patterns of waste materials from fish farms. We want everyone involved to have maximum confidence in the models used to locate fish farms and predict their environmental impact, minimise impact on the seabed, and ensure the sector is as sustainable as possible.

The SSPO is very supportive of the project. Iain Berrill, Head of Technical at the organisation, commented: “Being able to accurately predict how we interact with our environment is key, not only for the development of new and existing farms, but to our sector’s wider sustainability objectives, as presented in our Sustainability Charter.”