Scotland's 10 Year Farmed Fish Health: strategic framework

Framework document produced by the Farmed Fish Health Working Group.

Areas of Action

Delivery of this Farmed Fish Health Framework will require commitment and resource from all of its partners. Interaction with a number of related activities, including farmed-wild fish interactions, will help to inform the future development of the framework and its working activities. Central to the success of this Framework is the consideration of a number of core cross-cutting work streams, namely:

  • Information Flow and Transparency
  • Gill Health
  • Sea Lice
  • Cleanerfish
  • Production Cycle and on-Farm Management
  • Licensing Regime and Medicine Use
  • Climate Change and Ocean Acidification

For each key work stream, a Sub-Group will be established within three months of publication of this Framework to take forward the key initial priority objectives, determining milestones and long term work streams to help meet the objectives of this Framework. Membership of each the Sub-Groups will be adaptable and able to reflect the areas of work. The role of Chair for each Sub-Group will interchange between industry and Scottish Government, with a regular reporting mechanism to the overarching Framework Working Group. This will allow for progress to be assessed and the impact of developments to be incorporated into the thinking of the Framework Working Group and thus the creation of new, or the revision of current, milestones.

The Framework Working Group will be tasked to produce an annual update to the Scottish Government and the Scottish Parliament against progress made against the Farmed Fish Health Framework. The group will also identify appropriate vehicles and opportunities for the publication and sharing of best-practice that emerges as the result of the Sub-Group for the various work streams.

Further work will need to be progressed around the availability and need for focussed training/ professional development structures in light of the many activities outlined within this framework document. That may well necessitate a further work stream once the other areas of work have started to deliver.

The priorities identified for the work streams to date are;

Work Stream 1: Information Flow and Transparency

Mortality in farmed salmonids has many causes and is a primary area of focus for fish farming businesses. There has been a recognised deterioration (in the years to and including 2017) in farmed fish survival in Scotland.

Although this marine survival data has historically been collected in Scotland, the information has never been pulled together into one single reference point of mortality across the entire sector. The Farmed Fish Health Working Group ( FFHWG) aims to work towards presenting the annual mortality rates in the fish farming industry by cause. This will require standardised data collection. The FFHWG will set out clear ambitions to reduce mortality.

The FFHWG will work to ensure that the industry, Government and principal regulators agree ambitious targets to achieve a significant and evidenced reduction in mortality for salmon and trout, which will be world-leading and based on international comparisons of major farmed salmonid producing nations.


  • Develop a consistent reporting methodology for collection of information on the causes of farmed fish mortality over recent years.

  • Analysis of losses to inform priorities of the Farmed Fish Health Framework to ensure work is evidence based and focused.

  • Develop an action plan to tackle the underlying causes of mortality.

  • Provide survival data for marine rainbow trout and marine salmon and ensure that the Farmed Fish Health Framework activities remain appropriate.

  • Move to pro-active open site-level reporting of key statistics concerning fish health, including sea lice and mortality.

  • Develop a national approach to data-sharing and evidence-gathering that can enable evidence based decision making, best practice and promote openness and transparency within the Scottish industry.

Work Stream 2: Gill Health

Gill health has emerged as the key challenge to the farmed fish industry in the marine environment and is the most significant contributor to increasing marine mortality.


  • Establish a clearer understanding of the underlying environmental factors and increase awareness of key factors which contribute to gill health challenges.

  • Support research to better define interactions between farms environmental characteristics, gill health and risk of losses.

  • Better define best gill health surveillance practice and establish good practice on gill health for Scottish fin fish aquaculture.

  • Formulate a long-term approach to minimise losses from gill diseases

  • Convene appropriate best-practice events and workshops ( e.g. on availability and use of anti-fouling solutions to reduce net cleaning requirements).

Work Stream 3: Sea Lice

Sea lice treatment strategies have evolved from one which was based predominantly on medicinal control to a more balanced strategy, including the use of cleaner fish and physical removal, alongside the use of licensed medicines. This transition has brought with it a number of challenges related to biosecurity and welfare, primarily because it has increased the need for fish to be handled, which is a contributory factor in mortality. The activities of this work stream aim to continue improving control of sea lice on Scottish fish farms, building on and recognising current good practice and the wider environmental benefits, including a potential reduction in farmed – wild fish interactions.


  • Review Scotland's voluntary farmed fish sea lice compliance policy, including reporting requirements and intervention thresholds, and make recommendations to ensure that it remains fit for purpose.

  • Industry to further evolve its sea lice strategy from primarily a medicinal one to a balanced combination strategy (medicinal, physical and cleaner fish) through development of new best practice guidance. Treatment strategies will be site and area specific.

  • Develop and introduce a desk based pilot study (funded through members of the FFHWG) to look at the potential fish health and environmental benefits of consolidation of existing fish farms and identify how this could be made achievable through the current regulatory framework.

  • Create a sea lice modelling and farm connectivity action plan, identifying required resources and responsible parties. The plan should explore the use of hydrodynamic and other modelling types to manage sea lice infection pressure over larger areas and be complimentary to other environmental models used to support optimal site identification.

  • Based on the findings of the pilot study and sea lice connectivity action plan - review current Farm Management Area ( FMA) boundaries and their operation based on the latest scientific evidence and advice.

  • Develop an easily accessible information source which outlines the sea lice management 'tool box' available to the Scottish fish farming industry.

  • Develop and disseminate guidance on operational best practice for physical sea lice treatments

Work Stream 4: Cleanerfish

Cleanerfish offer a sustainable and environmentally positive method for reducing the impact of sea lice on salmonid growth, and assessment of the potential contribution of wild caught and hatchery cultivated supplies relative to future demand is essential.


  • Building on agreed management measures with the Scottish Government, define industry demand for farmed cleaner fish (wrasse and lumpfish) and the barriers to delivery.

  • Map out required research and development, investment and timescale to deliver total industry demand.

  • Review and assess the potential for cleanerfish use in rainbow trout cultivation.

  • Assess whether management measures are appropriate and proportionate to the current and anticipated future levels of sustainable wild wrasse fishing in Scotland.

  • Establish an international forum or platform in order to share cleaner fish husbandry best practice and establish best practice husbandry measures for the Scottish industry.

Work Stream 5: Production Cycle and on-Farm Management

Industry and research have improved fish farming cycles to allow for growth to an acceptable harvest weight and include good fish health and husbandry techniques such as fallowing. The increased ability to grow larger smolts provides the opportunity to reduce the marine grow out phase of farmed salmon, thus reducing the time spent in sea and the length of exposure to marine challenges such as sea lice. Reduction in time spent at sea may also in turn reduce treatment requirement, thereby extending the shelf life of sea lice medicines and slow down the build-up of chemical resistance within sea lice. Reduced time spent in the sea also has corresponding benefits in reducing environmental impacts, including those in the water column and sea bed.

Fallowing allows for a break in sea lice and other pathogen biological life cycles and could be done more frequently under shorter farming cycles. Contiguous area fallowing would also provide benefit for rainbow trout fish health and welfare, a concept which is yet to be explored fully.

The activities under this work stream aim to explore the potential mechanisms to optimise farmed salmonid health and welfare. This includes supporting the use appropriate and effective use of Acoustic Deterrent Devices on Scottish fish farms.


  • Review evidence to support the potential environmental and health benefits arising from input of larger smolts (and associated decrease in marine phase) and increased fallow frequency

  • Recommend best-practice to maximise smolt survival in the first 30 days at sea and the ability to shorten the marine phase of the production cycle.

  • Review rainbow trout production methods (inc. continuous stocking) and identify areas where the industry could support the move to contiguous fallowing if evidentially justified

  • Review how the regulatory framework can better encourage deployment of larger smolts, increased fallowing and improved health for salmon and rainbow trout.

  • Develop standards for the use of Acoustic Deterrent Devices ( ADDs) or alternatives on marine salmon farms.

  • Identify where support to fish farming companies is necessary and assist industry to prioritise robust ova selected for disease resistance to maintain and enhance Scotland's good health status.

  • Revise the recommendations of the Code of Good Practice with regards to ova selection.

Work Stream 6: Licensing Regime and Medicine Use

Ensure that the licensing regime remains fit for purpose and supports the innovation and adaptation of new fish treatment methods.


  • Revisit the conclusions of the Wellboat Working Group and progress to date, including;
    • the industry's current capacity for sea lice/particulate matter filtration and treatment of wellboat discharge, providing a timeline for industry-wide implementation and updating best practice standards for wellboat discharge within Scotland's regulatory regime.
    • explore new treatment technologies, including alternatives to wellboat treatment, which offer treatment containment and environmental benefits
    • exploration of assigned wellboat discharge zones where wellboat residues could be discharged following movement or treatment allowing for greater dilution of discharges.
  • Explore and progress ability to treat fish with medicines using well boats in addition to Controlled Activity Regulation consents which permit in cage bath treatments on farms.
  • Progress hydrodynamic modeling to demonstrate cumulative water body impacts in order to deliver the capability to identify optimum locations for organic deposition and water column measures
  • Encourage development of new medicines with the aim of increasing treatment flexibility and allowing the potential to explore treatment rotation in Scotland, within environmentally sustainable limits, appropriate use of veterinary medicines through 'cascade', and treatment residue containment and neutralization.

Work Stream 7: Climate Change and Ocean Acidification

Monitor, review and assess the impact of climate change and ocean acidification on Scottish waters and the implications for the marine aquaculture industry.


  • Consider the creation of real time monitoring of plankton in and alert of the occurrence of potentially harmful phytoplankton species.

  • Determine how best to measure changing climatic conditions in Scotland particular to aquaculture leading to an annual mapping exercise. This should include an assessment of currently available environmental data from around fish farms, for example real-time temperature data.


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