APP2026-00001445 Mowi Scotland Limited: Mullach Mor MPFF, Cullin Sound - EASR Application

Overview

SEPA is one of a number of organisations regulating finfish aquaculture. Anyone who operates a fish farm must have an authorisation from SEPA, under The Environmental Authorisations (Scotland) Regulations 2018 (EASR). When we receive an application for a new fish farm or to modify the operation of an existing fish farm, as part of our determination we will consider the risks to the water environment (including potential impacts to species and habitats), and the interests of other users of the water environment.   

If we decide to grant or vary an authorisation it will include conditions to protect the water environment. The person authorised to carry on the activity must do so in accordance with the conditions of the authorisation. 

We may also review the conditions of an existing authorisation from time to time to make sure they are still effective in achieving these aims.

Who regulates what in Scotland

What SEPA regulates

• Discharges of organic matter, medicine residues, other chemicals and the interaction between sea lice from fish farms and wild Atlantic salmon.

What others regulate

• Fish Health Inspectorate - Fish escapes and farmed fish health.
• Animal and Plant Health Agency and the relevant local authority - Fish welfare and disposal of farmed fish mortalities.
• Marine Scotland Licensing - Moorings and navigation.
• Relevant local authority - Visual amenity, noise and sea lice interaction with sea trout.
• Health & Safety Executive and the relevant local authority - Workforce safety.

Application details

We received an application from Mowi Scotland Limited at Mullach Mor MPFF  to operae a marine pen fish farm (MPFF).

A summary of their application is available below:

Mowi Scotland Limited proposes the installation of a new marine pen fish farm site off the north-east coastline of the Isle of Rum to farm Atlantic Salmon. The proposed biomass for the site is 2,650t. Fish would be farmed in 8 pens measuring 160m circumference, arranged in a 1(2x4) configuration, and held in 100m square grids. The application also seeks permission to use in-feed and topical bath medicines as part of a range of medicinal and non medicinal management tools to support fish health. A feed barge will service the proposed development located at the southeastern end of the pen group. 

• Activity form
• Non-technical summary 
• Site plan
• Hydrographic data report: Deployment ID446
• Hydrographic data report: Deployment ID450
• Community engagement report
• Equilibrium Enhancement Calculations
• Local Waste Solids Deposition Modelling Report
• Other marine users
• Marine Modelling
• Environmental Baseline and Habitat Assessment Investigation
• Environmental Monitoring Plan (EMP)
• Hydrodynamic Model Report
• Hydrodynamic and Dispersion Modelling Method Statement

Why your views matter

This is your opportunity to let us know your views on the application. The consultation will be open for 28 days from date of publication. We will consider any comments received between 9 July 2026 and 6 August 2026 before issuing the final decision.

Your comments will not be published on our public register unless you request us to do so.