Aquaculture: Finfish

The majority of aquaculture in Scotland is focused on finfish production, with this almost entirely focused on Atlantic salmon farming. In 2023, Scotland produced 150,949 tonnes of Atlantic salmon (Salmo salar) (Scottish Government, 2024). Other farmed finfish species include rainbow trout (Oncorhynchus mykiss), brown/sea trout (Salmo trutta), and halibut (Hippoglossus hippoglossus) (Natural Scotland, n.d. b; n.d. c).

Salmon are hatched and reared in land-based hatcheries before being transferred into caged areas in freshwater lochs. The salmon stay at these freshwater sites until they become smolts at around 1 year old. At this age they are able to survive in seawater and are then transferred into marine fish farms (Natural Scotland, n.d. a). Marine fish farms are located around the West and North of Scotland's coasts as well as around the Western Isles, Orkney, and Shetland (fig. 1). In addition, there are a small number of land-based tanks for fish farming which are pumped with seawater (Natural Scotland, n.d. b).

There is a continued presumption against further development of marine finfish farming sites along the North and East coasts of Scotland in in order to protect migratory fish species such as Atlantic salmon (Scottish Government, 2020). There are a small number of salmon hatcheries and sites focused on research and development in operation along the East coast to try and boost wild fish numbers.