Salmon & Trout Conservation Scotland launches parliamentary petition calling for tighter regulation of salmon farms to protect wild fish

The current regulatory regime for fish farms gives very little protection to wild salmon and sea trout and is untenable

Salmon & Trout Conservation Scotland (S&TCS) has today launched an online petition calling for statutory tighter regulation of salmon farms to protect wild salmon and sea trout.

The public petition "Protecting wild salmonids from sea lice from Scottish salmon farms", which is hosted on the Scottish Parliament's website, requests the Scottish Parliament to urge the Scottish Government to strengthen the legislative and regulatory control of marine fish farms in order to protect wild salmon and sea trout.

The petition is online at

The petition follows S&TCS's recent publication of a detailed report (Note 1) into the control of sea lice on fish farms in Scotland over the last two years. This highlights the gravity of the problem with sea lice and the need for urgent action from the Scottish Government to protect wild salmon and sea trout populations in the west Highlands and Islands that are already in trouble.

Andrew Graham-Stewart, Director of S&TCS, commented: "Scottish Government's lack of regulation has clearly been a major contributory factor in the industry's failure to keep sea lice numbers below acceptable levels.

"Our analysis shows that, between 2013 and 2015, the number of fish-farming regions failing to keep adult female sea lice numbers below the industry's voluntary Code of Good Practice threshold has been on an upward trend. Indeed the industry-wide problem with sea lice appears to be increasing and is certainly not under control."

Paul Knight, CEO of S&TC UK and Co-Chair of the NGOs at the North Atlantic Salmon Conservation Organisation (NASCO), said, "The current regulatory regime for fish farms in Scotland gives very little protection to wild salmon and sea trout and is untenable. If Scottish Government is to live up to its international obligations to protect wild fish, it must now bolster the regulatory control of salmon farming to limit any potential damage. Measures must include provision for proper sanctions against farms that transgress – including early culling or harvest. It is inexcusable that Scotland lags so far behind Norway in this respect." (Note 4)

Fisheries scientists are increasingly firm in their conclusions that sea lice produced on fish-farms harm wild salmonids, both at an individual and at a population level. (Note 3)

Official wild salmon catch statistics, the most commonly used measure of abundance, show that for the main aquaculture zone – the west Highlands (from Cape Wrath down to the Mull of Kintyre) and the Hebrides – the average annual salmon rod catch in the last ten years is 22% lower than that of the 1960s (commercial marine salmon farming began in 1970). In some smaller west coast rivers (such as the River Strontian) wild salmon are close to extinction.

In contrast for east and north coast rivers between the Tweed and Cape Wrath (an area that is virtually free of direct salmon farm influence) the average annual salmon rod catch in the last ten years is actually 29% higher than that of the 1960s. Furthermore all of the great west coast sea trout loch fisheries have collapsed.

S&TCS is adamant that Scottish Government now needs to adopt a range of measures, including:

  • requiring the immediate publication of farm-specific sea-lice data;
  • tougher regulation and inspection of fish farms;
  • a Government-led review of the current voluntary code of practice, replacing it with a statutory code, as provided for in the Aquaculture Act 2007;
  • introducing an 'upper-tier' sea lice threshold above which an immediate cull or harvest of farmed fish is required by law;
  • amending Scottish legislation to protect wild fish from potential damage caused by fish-farms, with inspectors given a legal duty to control sea lice on fish-farms in order to protect wild fish populations;
  • ordering the closure and / or relocation or persistently poorly-performing fish farms; and
  • signalling that the fish farming industry will be required eventually to move to full closed containment, to ensure a complete 'biological separation' of wild and farmed fish.

Hughie Campbell Adamson, Chairman of S&TCS, concluded:

"We urge all those wishing to see a recovery in depleted wild salmon and sea trout populations in the west Highlands and Islands to sign our petition. We are not advocating draconian measures such as the closing down of all salmon farms. All we are asking for is proper regulatory control when sea lice parasites multiply significantly to the detriment of wild fish."


1) The report – The Control of Sea Lice on Fish Farms in Scotland 2013-2015: a report for Salmon & Trout Conservation Scotland – is available via

As the graph below illustrates, the proportion of the total Scottish farmed salmon production in regions over CoGP thresholds shows an upward trend, with regions representing almost 60% of Scottish production being over the CoGP threshold of 0.5 adult female lice per fish in May 2015, at the peak of the wild smolt migration run, when wild fish are at their most vulnerable to infestation with sea lice emanating from fish-farms.

2) In 2015, the Scottish Government published its classification of the country's rivers' salmon populations. This places all the rivers in the west Highlands and inner Hebrides in the worst-performing category, with wild salmon stocks not reaching their conservation limits, which are a measure of the overall health of the population. No river within salmon farming's heartland of the west Highlands and inner Hebrides has, according to the Scottish Government's own scientists, a sufficient stock of wild salmon.

Sea trout populations too are under considerable threat. The west Highlands has in recent decades lost all of its formerly prolific loch fisheries for sea trout.

3) The negative impact of sea lice, produced in huge numbers by fish farms, on wild salmonids (salmon and sea trout) is widely accepted by fisheries scientists including the Scottish Government's own Marine Scotland Science.

See Marine Scotland Science (2013) Summary of information relating to impacts of sea lice from fish farms on Scottish sea trout and salmon – 4th April 2013 – available at

A paper published in 2013 by a group of fisheries experts from Norway, Canada and Scotland re-analyses data from various Irish studies and shows that the impact of sea lice on wild salmon causes a very high loss (34%) of those returning to Irish rivers – see M Krkosek, C W Revie, B Finstad and C D Todd (2013) Comment on Jackson et al. Impact of Lepeophtheirus salmonis infestations on migrating Atlantic salmon, Salmo salar L., smolts at eight locations in Ireland with an analysis of lice-induced marine mortality – Journal of Fish Diseases.

Most importantly, there is clear evidence that both wild salmon and sea trout are in decline in Scotland's 'aquaculture zone', whereas, generally, populations have stabilized on the east and north coasts where there is no fish-farming see

This year, fisheries scientists from Norway, Scotland and Ireland reviewed over 300 scientific publications on the damaging effects of sea lice on sea trout stocks in salmon farming areas, and examined the effect of sea lice on salmon, concluding that sea lice have a potential significant and detrimental effect on marine survival of Atlantic salmon with potentially 12-29% fewer salmon spawning in salmon farming areas.

The researchers concluded that:

"Salmon lice in intensively farmed areas have negatively impacted wild sea trout populations by reducing growth and increasing marine mortality. Quantification of these impacts remains a challenge, although population-level effects have been quantified in Atlantic salmon by comparing the survival of chemically protected fish with control groups, which are relevant also for sea trout. Mortality attributable to salmon lice can lead to an average of 12?29% fewer salmon spawners.

Reduced growth and increased mortality will reduce the benefits of marine migration for sea trout, and may also result in selection against anadromy in areas with high lice levels. Salmon lice-induced effects on sea trout populations may also extend to altered genetic composition and reduced diversity, and possibly to the local loss of sea trout, and establishment of exclusively freshwater resident populations."

See Thorstad , E , Todd , C D , Uglem , I , Bjorn , P A , Gargan , P , Vollset , K , Halttunen , E , Kalas , S , Berg , M & Finstad , B 2015 , ' Effects of salmon lice Lepeophtheirus salmonis on wild sea trout Salmo trutta – a literature review ' Aquaculture Environment Interactions , vol 7 , no. 2 , pp. 91-113 . (at

4) The sea lice regulatory position in Norway is explained here: