Marine aquaculture

A variety of fish species are grown in farms around the Scottish coast - salmon, trout, cod, halibut, and others - as well as farming of shellfish such as mussels, oysters and scallops. In addition, there are developing commercial interests in growing novel groups such as sea urchins and seaweeds.

Finfish aquaculture

In Scotland marine aquaculture is dominated by the production of salmon. Salmon farming, in common with the production of all marine fish species, takes place almost entirely in floating net cages. They are fed with specially formulated pelletized diets, of which a small proportion along with faeces from the fish, are released from the cages and into the water column, to be deposited on the seabed. These discharges of waste feed and faeces, along with residues of medicines used to treat the fish when they suffer from diseases or parasite infestations, may pose a risk to the environment. 

Regulation of fish farms

In common with any industry which makes discharges to the aquatic environment, operators wishing to establish a fish farm in the sea around Scotland must apply for and be granted a licence under the Water Environment (Controlled Activities) (Scotland) Regulations 2005 (CAR). These regulations provide SEPA with powers to ensure that activities which may pose a risk to the water environment are controlled. SEPA makes sure this is the case by setting limits on the amount of fish that can be held in the cages and thus the amount of food used. SEPA also protects the environment by limiting the amount of certain medicines that can be administered and discharged. In setting these limits, SEPA aims to ensure that the fish farm is operating within the capacity of the environment or in some sense is in harmony with the sea in the location in which it is sited.

Pre-consultation

The process of determining what the appropriate size of the farm is for a given location is quite complex. Prior to submitting an application, operators are recommended to discuss their proposals with SEPA. This pre-application consultation can avoid potentially costly difficulties and disappointment should SEPA determine that the proposals are inappropriate for the site concerned. SEPA offers the opportunity for pre-consultation without prejudicing the formal application process. Further details with respect to the required scientific supporting information can be found in the pre-application process document.

Licence applications and modelling

The process of applying for a CAR licence involves a number of steps and includes an advertising and consultation process. Details of the steps taken in the determination of a CAR licence for a fish farm are described in detail in the fish farm manual. For non-fish farm discharges, please refer to the guidance pages within the water regulation section.

Applicants must also submit information on the physical, chemical and biological condition of the seabed. They must also measure the currents in the area and conduct computer modelling simulations showing how waste will be dispersed from the site. Use the menu on the left to find out more.

Licence determination and site monitoring

Following submission and advertising of the application, SEPA will consider the proposals and either grant or refuse a licence. Where a licence is granted and a farm is developed, SEPA will undertake monitoring and inspections of the farm and the operator will also be required to commission regular studies of the impact of the farm on the seabed. SEPA recovers part of the cost of this monitoring regime through the levying of charges - see the CAR charging scheme for details. Fish farmers also make data returns to SEPA detailing the scale of the discharges from each of their farm premises. This data forms a large part of the publically available Scottish Pollutant Release Inventory (SPRI). 

Contact us

  • General enquiries regarding fish farm applications, inspections and the regulatory regime should be directed to the relevant local SEPA Office.

  • For enquiries regarding marine biology and chemistry and monitoring survey techniques contact Marine Science at the Dingwall Office or via e-mail at FFMarineScience@sepa.org.uk

  • For enquiries regarding modelling contact the OceanMet section at the Dingwall Office or via e-mail at FFModelling@sepa.org.uk

  • For queries regarding data returns contact Marine Science at the Dingwall office or via e-mail at FFBiomass@sepa.org.uk