Freshwater aquaculture

Freshwater Aquaculture Production in Scotland

Currently, Scotland is the largest producer of farmed salmon in the EU and is the third largest producer in the world  - 129,000 tonnes in 2007. To stock the salmon farms, juvenile salmon must first be produced. These fish are then transferred to sea cages once these fish reach the 'smolt' stage when they can survive in the sea. Currently, there are 135 freshwater production units in Scotland, producing 38.1 million smolts in 2007.

However, aquaculture in Scotland also includes farm production of brown trout, rainbow trout and Arctic charr for table and fishery purposes. The most significant of these is rainbow trout , producing 7,414 tonnes in 2007. At 298 tonnes and 4 tonnes respectively, the production levels of both brown/sea trout and Arctic charr are considerably lower. Some of these fish are destined for the table, but others (particularly brown trout) are used for fishery, or re-stocking, purposes.

Scottish Natural Heritage and Freshwater Aquaculture

Scottish Natural Heritage encourages the aquaculture industry to be sustainable in both environmental and socio-economic terms, and to maintain or enhance nature and landscapes. Thus, as a statutory consultee on freshwater aquaculture developments Scottish Natural Heritage will work with the aquaculture and fishery sectors, local authorities and others to ensure that concerns over Scotland's wild fish, pearl mussel populations and other fauna are reflected fully in the future development of freshwater aquaculture.

We are a member of the Tripartite Working Group  and play an active role in the commissioning of research used to underpin the industry in Scotland through the Scottish Aquaculture Research Forum  . We encourage the appropriate scale, location and design of aquaculture developments to minimise negative impacts on freshwater environments, landscape and recreation. We recognise that these impacts can be both localised and far-field, such as the impacts of escaped salmonids on wild fish stocks.

Issues associated with freshwater aquaculture

There are a number of issues of concern that are commonly associated with  freshwater and marine aquaculture.

Containment

Escaped fish may impact wild fish in a number of ways. For example, these fish may transfer disease; occupy valuable freshwater habitats to the exclusion of wild fish and interbreed with wild fish, leading to a loss of genetic integrity. Any escapes of fish from any registered fish farm or holding establishment must be reported to the Scottish Government  within 28 days.

Disease and Parasite Transfer

The transfer of disease to wild fish are covered by the Diseases of Fish Acts 1937 and 1983 which requires fish farmers, District Salmon Fishery Boards and Fishery Trusts, to report the symptoms of fish diseases to the Marine Scotland Fish Health Inspectorate as soon as they are detected. The EU has classified notifiable diseases    into three categories depending on their distribution within the EU and potential impact. In Scotland, the List I disease, Infectious Salmon Anemia  [ISA] and List III parasite Gyrodactylus salaris    (which is present in Europe but not yet the UK) have received the highest public and media interest.

Water Quality and Quantity

The Scottish Environment Protection Agency    is the lead body for regulating activities which impact on the water environment. These activities include a number of activities that may impact fish farm facilities, such as, discharges to surface water, abstractions, removal of sediments and the replacement of in-stream structures, such as weirs. To undertake any of these activities, all operators must have an appropriate Controlled Activities Regulations  licence.

Potential developers may also have to have regard to landscape  impacts. Local Scottish Natural Heritage staff will be best placed to advise on this aspect of any new development. For land-based production units, water abstraction and screening to ensure that wild fish are not allowed to enter the farm may also be issues of concern.