New S&TCS analysis shows how wild salmon rod catches in the main salmon farming region of the west Highlands and Islands lag far behind those of the East coast

“The only significant difference between the two coasts is the presence of aquaculture on the West”

Salmon & Trout Conservation Scotland (S&TCS) has today published a new analysis of official wild salmon rod catch statistics, which confirms that rivers in the salmon farming heartland of the West coast are lagging far behind those of the essentially aquaculture-free East coast.

The findings show that:

  • The five year average catch for the East coast rod fishery (from Tweed to Cape Wrath) increased by approximately 40% between 1970 and 2014.
  • The five year average catch for the West coast rod fishery (from Cape Wrath to Mull of Kintyre including the Hebrides) declined by 2014 to 76% of its 1970 value.
  • If the West coast catches had tracked the pattern of the East, rod catches would have been 80 per cent higher in 2014.
  • In the worst affected area of the West (the mainland from Ardnamurchan Point to Mull of Kintyre) the rod catch was by 2014 around 50% of its 1970 level. If this area had followed the East throughout, rod catches would be almost three times higher than those recorded today.

The analysis "Comparison of Scottish East and West coast salmon fisheries" is available here:

Andrew Graham-Stewart, Director of S&TCS, said:

"Rod catch statistics are the main measure used to assess the conservation status of salmon in Scottish rivers and this analysis underlines the stark contrast between the fortunes of wild salmon in the East and West coasts in the last 45 years. The vast majority of rivers on the West Coast and Islands are in the Scottish Government's category 3 – the most threatened – and the only significant difference between the two coasts is the presence of aquaculture on the West. The salmon farming industry in the West has grown inexorably since 1970.

"Our analysis fundamentally contradicts the misguided and disingenuous contention of representatives of the salmon farmers who maintain that there is no 'evidence' that their activities have an impact on wild fish numbers. Misleadingly they employ all-method figures (including net-caught) for salmon both East and West coasts to 'show' similar declines, thus 'proving' that salmon farming is not to blame in the West."

Mr Graham-Stewart continued:

"For any comparison to be meaningful, one must strip out the distorting factor of netting catches. Between 1970 and 2014, the coastal netting industry declined by a massive 95% in the East and 99% in the West. This reduction in netting of 380,000 fish would have led to increased rod catches if other factors were not involved. Clearly this is the case in the East but not in the West."

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

"The regional picture in the West coast masks just how serious the situation is in some rivers. It is surely no coincidence that the only recent extinctions or near-extinctions of wild salmon from entire river systems in Scotland have occurred in the salmon farming regions of the west Highlands and Islands. One notable example is the Lochaber's River Strontian, previously (before the advent of intensive salmon farming in the adjacent sea loch) a productive fishery, where the local fisheries trust was unable to find any adult salmon with which to initiate a restocking programme.

"Whilst our analysis excludes sea trout, it is also relevant to emphasise that all of the great west Highland loch fisheries (such as Loch Maree) are now virtually devoid of sizeable sea trout (1 lb and upwards) – on which such fisheries depend. Historically, these loch fisheries were very important to local economies, most of which have been severely damaged in recent years as sea trout stocks declined. Again it is no coincidence that these lochs all drain into salmon farming sea lochs. In contrast, whilst East coast sea trout populations have fluctuated in the last 40 years, there has been no collapse and there are still fair numbers of good-sized fish."

Mr Graham-Stewart elaborated:

"There will be no improvement in West coast salmon and sea trout numbers whilst salmon farms are permitted to pump out billions of sea lice parasites into the wider environment with absolute impunity. To date Scottish Government remains impervious to and dismissive of any pressure to regulate the industry in a way that gives any meaningful protection to wild fish."



1) Earlier this month S&TCS submitted a formal complaint to European Commission with a view to securing better protection for wild salmonids from harm caused by the salmon farming industry The full text of the complaint is available at

2) In December 2015, Salmon & Trout Conservation Scotland (S&TCS) published a detailed report (see into the control of sea lice on fish farms in Scotland over the last two years, brought into sharp focus the seriousness of the problem with sea lice and the need for urgent action from the Scottish Government to protect wild salmon and sea-trout populations that are already in trouble. The Report highlighted many regions of the Scottish Highlands and Islands where fish farms were collectively above, often very significantly above, the industry's own 'good practice' threshold (based on the number of adult female lice per farmed fish). At many of the fish-farms, despite repeated chemical treatments against sea lice, including using synthetic pyrethroid and organophosphate chemicals, the regional on-farm sea-lice levels remained stubbornly high. The Report made a number of recommendations for action from the Scottish Government, which the supermarkets are encouraged to support, 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;
– 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.

3) Just what is the problem with sea lice?
Adult wild salmon are perfectly adapted to coping with a few sea lice. Background levels of these parasites occur naturally in the sea. However the advent of salmon farming, particularly in fjordic sea lochs, has led to a fundamental change in the density and occurrence of sea lice in parts of the coastal waters of the west Highlands and Islands. Even one or two mature female sea lice per fish within a set of cages housing hundreds of thousands of farmed salmon amounts to a rampant breeding reservoir pumping huge numbers of mobile juvenile sea lice out into the local marine environment. The consequences when wild salmon and sea trout smolts, the metamorphosing fragile skin of which is not adapted to cope with more than the odd louse, migrate from local rivers into this "sea lice soup" can be devastating.
Carrying an unnaturally high burden of sea lice is known to compromise severely the survival of juvenile migratory salmonids. Lice feed by grazing on the surface of the fish and eating the mucous and skin. Large numbers of lice soon cause the loss of fins, severe scarring, secondary infections and, in time, death. Quite literally, the fish are eaten alive. Badly infested salmon smolts disappear out to sea, never to be seen again. In contrast afflicted sea trout smolts remain within the locality and they, together with the impact of the deadly burdens they carry, are more easily monitored through sweep net operations.

4) 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 with the number of sea trout returning to Scottish rivers in decline, with the 2013 rod catch being the lowest on record according to Marine Scotland Science. The west Highlands has in recent decades lost all of its formerly prolific loch fisheries for sea trout.
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 – see Annex 1 of the Complaint.

5) 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.

6) In 2015, 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