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FAQs on Sea Lice Regulatory Framework Implementation

Why is a sea lice framework needed?

Populations of wild Atlantic salmon have been in serious decline in recent decades and are now at crisis point. The pattern of decline is repeated across the salmon’s North Atlantic range and is likely caused, at least in part, by the effect of climate change on the survival of salmon during their time at sea.

To build resilience of Scotland’s salmon populations and help transform their fortunes, the Scottish wild salmon strategy is designed to ensure that the breadth of pressures acting on salmon within Scotland’s rivers and coastal waters are appropriately managed.

One of the pressures that wild salmon can face in coastal waters is sea lice. Salmon farms can substantially elevate levels of sea lice in coastal waters and have the potential to increase risks to wild salmon growth and mortality. The purpose of the new sea lice regulatory framework is to ensure effective management of this potential pressure.

Why is SEPA the lead regulator for sea lice and wild salmon and sea trout interactions?

Scottish Ministers set up the independent Salmon Interactions Working Group to examine the interactions between farmed salmon and wild salmon and sea trout populations and make recommendations on the management of those interactions.

The group acknowledged the potential hazard that fish farming presents to wild salmon and sea trout and agreed to look at how the potential risk could be minimised. After doing so, the Salmon Interactions Working Group report recommended:

  • A single lead body should be assigned responsibility for regulating wild and farmed fish interactions.
  • Robust conditions, based on an adaptive management approach, to safeguard wild salmon and sea trout should be contained within a licence rather than through planning consent.

In October 2021, in the Scottish Government Response to the recommendations of the Salmon Interactions Working Group, Scottish Ministers identified that SEPA would become the lead body responsible for managing the interaction between sea lice from fish farms and wild salmon and sea trout.

How have you developed the framework?

Between October 2021 and December 2023, SEPA engaged with and listened to a wide range of stakeholders to help it develop the framework, including fish farm businesses, wild fishery managers, environmental NGOs, other public bodies, coastal community groups and scientists specialising in sea lice and wild salmon interactions. The engagement included multiple meetings and workshops with stakeholders and two public consultations.

The result, which builds on the recommendations of the Salmon Interactions Working Group, is a spatially based and adaptive regulatory framework, which will underpin a risk targeted and evidence-led approach to protecting salmon and sea trout from sea lice from fish farms.

When does the sea lice framework start?

The framework for protecting:

  • wild salmon populations started on 1st February 2024; and
  • sea trout populations will start in March 2025.

The framework for protecting sea trout will be based on a different approach to that for wild salmon, reflecting the different lifecycles of the two fish species and current scientific understanding of risk. The sea trout framework will take the form of an adaptive approach under which regulatory action will be informed by targeted monitoring of wild sea trout populations to identify if sea lice infections are resulting in harm. This approach will build on the current approach used by local authorities.

How does the framework affect applications for new fish farms?

From 1st February 2024, all proposals for new farms or expansions of existing farms are being assessed by SEPA to determine whether they could pose a risk to wild salmon populations.

Where, based on this risk assessment, SEPA concludes that action is required to manage interactions to protect wild salmon, it will set permit conditions that limit the maximum number of sea lice on the farm when authorising the development; or, if necessary, refuse to authorise the development.

If SEPA concludes that the relative risk to wild salmon posed by a farm development is very low, no further action will be required.

How does SEPA assess the risk to wild salmon?

SEPA has developed a purpose-built screening model that allows it to assess the relative risk to wild salmon posed by existing farms and proposed farm developments.

The screening model is designed to be appropriately precautionary. This enables SEPA to use it to identify those farm development proposals and existing farms that it is confident are unlikely to pose a significant risk to wild salmon populations and, hence, do not require further assessment.

If further assessment is needed, this will be carried out using more refined models that have been validated against specially collected monitoring data. The more refined modelling will either be undertaken by SEPA or, if undertaken by a fish farm developer, audited by SEPA. The results will be used to decide on the action required to protect wild salmon.

How will SEPA develop its understanding of risk?

SEPA had to base its initial screening assessments on assumptions about the possible number of sea lice on existing farms. In March 2024, fish farm companies must provide SEPA with information on farmed fish numbers and average sea lice numbers per fish on their farms over the past six years. Once it receives this information, SEPA will use it to update its risk assessments. SEPA expects to complete this work by 2024.

How does the framework affect existing sites?

SEPA has used its screening models to assess:

  • the relative exposure to sea lice to which different wild salmon populations may be subject; and
  • the potential relative contribution of each existing farm to the sea lice exposures to which wild salmon may be subject.

This information will be used to target detailed studies. The studies will involve refined modelling and monitoring programmes to determine the actual risk to salmon populations. Where the studies conclude that sea lice from existing fish farms are affecting wild salmon, SEPA will take regulatory action to reduce sea lice numbers on the farms concerned so that salmon populations are protected. Any such action will be proportionate to the farms’ contributions to sea levels.

While the detailed studies are being undertaken, SEPA will take regulatory action to ensure that sea lice numbers on those farms with the potential to make an important contribution to the exposure of wild salmon to sea lice do not increase.

How many existing farms pose a risk to wild salmon?

SEPA has used the outputs of its screening model to rank the potential relative risk posed by existing farms to wild salmon populations.

The assessment ranked 164 farms on the West Coast and Western Isles, placing 19 in the highest relative risk category; another 19 in the next highest; 23 in the third highest; and the remaining 103 farms in the lowest relative risk category.

The principal purpose of the ranking is to enable SEPA to prioritise more detailed studies to understand whether sea lice from existing farms are causing harm to wild salmon populations. The identification of a farm in the highest potential relative risk category means that the farm has the potential to be a larger contributor than other farms to sea lice exposure in an area of sea in which wild salmon are likely to experience relatively high exposures to sea lice. It does not mean that there is evidence that wild salmon are being harmed.

The ranking of farms’ relative risk may change when SEPA updates its screening model using data from fish farm companies to improve on its current understanding of the potential number of sea lice on existing farms.

Will farms in the highest relative risk category be able to expand?

A proposal to expand a farm in the highest relative risk category will be considered in the same way as any development proposal.

SEPA will undertake a bespoke screening assessment using the best available information provided by fish farm companies on the total numbers of sea lice on existing farms in the sea area concerned.

If based on this assessment, SEPA still concludes that the development could pose a risk and further assessment is needed, the developer will have options of:

  • Working with SEPA to enable further assessment using a more refined model that is tested and validated against environmental monitoring data; or
  • Modifying their development plans to reduce the number of sea lice on the farm during April and May when salmon are migrating through coastal waters. For example, this might involve the developer proposing to shorten the time farmed fish will be held on the farm so that the farm is fallow or only recently stocked in April and May.

How will you measure the effectiveness of the framework?

SEPA is developing monitoring programmes with partners to allow it to track changes in the condition of wild salmonid populations linked to the implementation of the framework.

The monitoring programmes will require careful design and subsequent analysis of their results to enable the effects of the framework to be distinguished from changes to other pressures on wild salmon populations that may also be occurring.

How does this work fit into SEPA’s wider duties to protect wild salmonids?

SEPA is responsible for producing national plans of action that drive improvements in the water environment. These River Basin Management Plans include a wide range of actions to address pressures on rivers and coastal waters that can affect wild salmon and trout populations.

Under the plans, SEPA is responsible for regulating the following pressures; and, if necessary to improve the condition of the water environment, driving reductions in them:

  • discharge of pollutants from industry and urban wastewater treatment works;
  • diffuse inputs of pollutants into the water environment via rainfall runoff from farmland, forestry and urban areas;
  • effects of dams and weirs on fish migration;
  • abstraction of water; and
  • damage to river habitats resulting from building and engineering works.

SEPA will use the new sea lice regulatory framework alongside its regulation of the above pressures to help protect and improve the water environment and to contribute to achieving the goals of the Scottish Wild Salmon Strategy.