The Salmon and Trout Association (Scotland) (S&TA(S)) is asking major supermarket chain Asda to take a stand for wild salmon conservation by ending its relationship with Wester Ross Fisheries Limited, a company showcased in Asda’s magazine in July this year, because of its appalling sea-lice record and the threat that poses to wild salmon and sea trout.

The very latest quarterly sea lice report (for July to September 2013) published by the salmon farming industry reveals that in the ‘Kennart to Gruinard’ region of the north-west Highlands, where there are seven farms operated by two companies, Wester Ross Fisheries Limited and Scottish Sea Farms Limited, adult female sea-lice numbers were way over the industry’s own threshold for all three months. In September, the monthly lice count on farms in this area was over nine times the threshold. Those levels have been over that threshold for each of the nine months to September.

The production of huge number of juvenile sea lice by these farms presents an unacceptable threat to the conservation of wild salmon and sea-trout (see Note 1).

Hugh Campbell Adamson, Chairman of S&TA(S), said:

“The sea-lice numbers in the region where Wester Ross Fisheries have all their marine farms are shocking and the salmon farmers in these areas have lost all control. We call on Asda to make a stand and end its relationship with Wester Ross Fisheries Limited in the interests of the conservation of Scotland’s iconic wild salmon and sea trout.  Nor is this message just for Asda. All supermarkets must stop hiding behind opaque certification schemes that mean little in practice. They need to take an honest look at their producers and where they are found wanting, where they are causing damage to wild fish conservation, those producers should be dropped”.

The poor record just goes on

The poor record of on-farm sea-lice control on Wester Ross Fisheries farms is not something new. Prior to 2013, Fish Health Inspectorate (FHI) reports of inspections conducted at Wester Ross Fisheries’ farms have shown poor lice control on very many occasions. FHI inspections at Ardmair in Loch Kanaird on 10th November 2009, 15th June 2011, 2nd August 2011 and 25th July 2012, at Corry in Loch Broom on 21st March 2011 and 6th June 2011 and in Little Loch Broom, at Ardessie on 7th June 2011, 2nd August 2011 and 16th May 2013 all recorded that sea-lice levels of the farmed fish breached the suggested adult female sea lice threshold in the industry’s own Code of Good Practice during the period that records were inspected.

Why are sea lice on fish-farms such a threat to wild salmon and sea trout?

The negative impact of sea lice (see Note 2), 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 Notes 4 and 5).

Most recently, a new 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 salmonid rivers (see Note 6).

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 Note 7).



1) 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 literally billions 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” are devastating.  A burden in excess of 13 pre-adult 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.

2) Asda magazine from July 2013 ran an article suggesting that Asda sources at least some of its farmed salmon from farms operated by Wester Ross Fisheries Limited in Loch Broom and Little Loch Broom in Wester Ross. While the Asda magazine article, “Premium Salmon”, presents a rosy picture of the operations of Wester Ross Fisheries, data obtained by the S&TA(S) from the Government’s own Fish Health Inspectorate, the local Wester Ross Fisheries Trust and the Wester Ross Area Salmon Fishery Board suggests a slightly different picture, particularly in relation to parasitic sea-lice released from the farms in huge numbers. The S&TA wrote to Asda in September asking for an urgent meeting, but has received no reply.

3) The SSPO report giving aggregated sea lice data from fish farms from July to September 2013 and earlier reports are available for download via this link: http://www.scottishsalmon.co..uk/science/sea_lice/regional_reports(1).aspx

4) 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 www.standupforwildsalmon.org. Note that Marine Scotland Science acknowledges that compliance with the thresholds within the Code of Good Practice is not necessarily sufficient to ensure that juvenile sea lice emanating from the fish farms do not damage wild fish.

5) See also S&TA (2013) Recent research and findings on the impact of salmon aquaculture on wild salmonids – see www.standupforwildsalmon.org

6 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.

7) http://www.rafts.org.uk/wp-content/uploads/2011/10/East-v-West-final-RWB.pdf

8) For further information on the work of the S&TA (Scotland) see www.salmon-troutscotland.org