Does salmon farming have an impact on the seabed?
At Mowi, we have recently implemented a new biodiversity strategy which ensures our commitment to a healthy environment and farming the ocean responsibly. A healthy marine environment is critical to salmon farming to produce our salmon under optimal conditions for them to thrive and be healthy.
The aquaculture industry has some of the strongest regulations globally, particularly around environmental protection. Before a fish farm is consented to and developed, a significant amount of work goes into ensuring that that farm is unlikely to have any long-term impacts on the environment. Once the farm is consented to, there is an ongoing monitoring programme to ensure that the environment is protected.
Mowi adheres to ongoing rigorous operations to ensure no negative impacts. For example, once our salmon are harvested, their home also becomes fallow (or empty) for a while. Similarly to agriculture, where farmers let the soil rest between harvesting crops, we leave our pens empty, which gives the seabed time to break down organic matter naturally and gives our farmers a chance to make any necessary repairs and upgrades to the farms. It’s a simple concept, but it plays a significant role in keeping the seabed healthy and our fish thriving.
In recent years, Mowi Scotland conducted a three-year post-closure environmental study around the former Isle of Ewe fish farm on the northwest coast of Scotland. Through the operational life of fish farms, environmental effects are limited and managed by a robust regulatory framework underpinned by environmental standards that ensure the protection of the seabed and biodiversity. However, limited information was available on how the seabed responds following the cessation of fish farming operations.
The aim of the study, which was conducted alongside delivery partners Benthic Solutions and Applied Genomics, and supported by Salmon Scotland, was to assess the environmental condition and trajectory of seabed recovery following the closure of the Loch Ewe fish farm. The project included monitoring seabed samples, habitat mapping, and an eDNA analysis covering a much bigger biodiversity profile. Over three years, the project concluded that the seabed can and will recover quickly. In 2020, 67% of the samples met the conditions for ‘Good Ecological’ status. In 2021, this percentage increased to 80%; in 2022, it increased to 93%; and in 2023, 100% of the samples met the conditions for ‘Good Ecological’ status.
Reflecting on the results, Connie Fairburn, Senior Environmental Analyst at Mowi Scotland said: “There are many misconceptions about the environmental impact of the aquaculture industry. However, this project provides solid evidence that seabeds can recover upon cessation of fish farming operations.”
At Mowi, we prioritise protecting the environment where we grow our salmon and our dedicated employees live and work. By farming within the environment’s capacity, we know we leave no permanent impact.
