Highland Council Must not Permit Expansion of Polluting Fish Farms

A letter of objection from Salmon & Trout Conservation Scotland to the expansion of a fish farm which has been recommended for approval by Highland Council.

Dear Sirs,

Gob na Hoe Marine Cage Fish Farm, Loch Dunvegan, Skye

In this matter, I act for Salmon & Trout Conservation Scotland.
S&TCS objects strongly to the application to increase the permitted biomass from 2021 tonnes to 2215 tonnes at the above farm for the reasons set out below.

Benthic survey
The last benthic survey, dated 02/08/2017, is recorded on the Scotland’s Aquaculture website as “borderline”. SEPA categorises ‘borderline’ reports as requiring that “the responsible persons attention should be drawn to the clear indication that the performance of the site is close to having an unsustainable impact and the responsible person should at least be required to consider taking further action such as a review of the management of the site to improve efficiency of feed use or an extension to the fallowing period”1.

There is no indication in the application of any such consideration or review being undertaken.

The previous survey, dated 08/06/15, was “unsatisfactory”. An “unsatisfactory” classification is “an indication that the emissions arising from the site in question are of a scale that is beyond the assimilative capacity of the local environment. This classification may relate to impacts on benthic fauna or sediment chemistry, unacceptable infeed medicine residues concentrations, or a combination of these parameters”2. The earlier 2013 survey was also “borderline”.

Emamectin benzoate (Slice) remains one of the three main CAR-licenced chemicals that the applicant seeks to continue to use to control sea lice at Gob Na Hoe.

The site has treated with Slice in each of the last four production cycles and twice in each of the last two cycles.

Clearly, the site remains dependent upon Slice, at the currently permitted biomass of farmed fish, to control the lice on its fish.

Residue sampling undertaken on 8th June 2015, stated to have been undertaken 220 days after the last treatment shows a breach of cage EQS at one replicate sample. However, sampling undertaken 133 days after the 2014 treatments, March 2015, showed massive breaches, in one replicate an order of magnitude higher than the EQS, at the cage edge and one replicate breach at 100m:

Capture L blog

However, research by SAMS had shown that the negative effects of the use of emamectin has been underestimated and that cage edge and far-field EQS values are not sufficiently protective of crustaceans in the wider marine environment. The SAMS report from 20163 raised serious concerns that residues of Slice, excreted by farmed fish and spread into the wider sea loch environment, have had a far greater impact on wild crustaceans than was predicted when Slice was first licenced.

SAMS concluded that “the evidence indicates a wide scale cumulative impact and
incomplete recovery between successive emamectin benzoate treatments…..”,
the ecosystem consequences of the observed reduction in crustacea are not known, but crustacea include important fishery species such as crabs and lobsters…”
“the evidence suggests that benthic crustacean may not be adequately protected by the current regulation of EMB use in Scottish salmon farms”.
our results indicate that, even allowing for regional differences in the physical properties of the receiving environment, the use of EMB is associated with substantial, wide scale reductions in both the richness and abundance of non-target crustacea. Given the findings in this report we believe there is an urgent requirement to… consider the likely ecosystem consequences of large scale reductions in crustacean richness and abundance at the scale of sea lochs”.

SEPA should also note that small crustaceans are important prey species, forming part of the diet of sea trout.

Despite SEPA’s Agency Management Team (AMT) being asked in February 2016 to
approve appropriate regulatory action to effect a managed phase-out of the use and discharge of Slice on Scotland’s fish farms, reducing use immediately and setting “a date for the complete suspension of the relevant CAR licence conditions to prevent use of Slice at all fish farms in Scotland (at present we recommend a target of 2 years to achieve this phase-out, (in any event it should not exceed 3 years)”4, subsequently, the SAMS report was subject to peer review commissioned by SARF, but, astonishingly this was conducted by 5 out of 6 reviewers appointed by the manufacturer of Slice, Merck.

SEPA’s handling of the Slice issue led to public accusations of cover-up and undue pressure being brought to bear on SEPA to continue to allow Slice to be used, despite the SAMS’s conclusions5. Since then, there have been four Decisions from the Scottish Information Commissioner concerning SEPA’s failure to provide full information on Slice and the potential for a ban, all finding against SEPA6.

SEPA commissioned WRc7 to propose new EQS values for emamectin benzoate, which
then proposed new levels which would effectively have precluded the use of Slice for sea lice control. Under further pressure from the fish farmers, SEPA then issued a further call for information and UKTAG was initially expected to recommend a new EQS to Scottish Ministers at Easter 20188. The decision was then expected in June. It is now expected in August.

Despite the obvious bending-over backwards that SEPA has performed or been forced to perform for the industry since 2016, this exercise may yet effectively end the use of Slice completely. At the very least, even SEPA must expect that any revised EQS for emamectin benzoate will markedly reduce the quantity of Slice that can be used, making effective control of sea lice at the current permitted biomass at Gob Na Hoe even less likely.

SEPA’s own Fish Farm Manual, published in 2005, indicates that “in order to better protect wild salmonid stocks however, SEPA has adopted a Limiting Factor approach to consenting marine caged fish farms. SEPA may, in determining biomass limits for sites where proximity to important wild stocks is considered as a significant issue, impose a biomass limit equivalent to that biomass which can be effectively treated for sea lice infestations using an authorised sea lice medicine” and that, when setting consent limits, “in certain instances to protect important wild salmonid stocks, SEPA will limit the biomass to that which can be treated at the site using an authorised sea lice medicine.

Given this, SEPA should not consider permitting any increase in permitted biomass at Gob Na Hoe.


SEPA stated in 2005 that it sought “to prevent development of sites which will need to depend upon routine and prophylactic chemical use” to control sea lice.

However, the site at Gob Na Hoe is patently dependent upon azamethiphos to treat its sea lice.

In the last production cycle, it treated with azamethiphos for no fewer than 8 months, in August, September, November and December 2016, January, February, March, April and May 2017, as shown below:
Capture L 2

After use, azamethiphos remains dissolved until it is broken down into non-toxic derivatives, for which a decay half-life of 8.9 days has been determined. This means azamethiphos remains active for some time after treatments have finished on fish farms and treated water has been released into the wider sea loch. If repeat treatments then follow only a matter of a day or two after each other, depending on the tides, currents and water exchange at a site, azamethiphos may remain at ecotoxicologically significant levels outside the cages for some

SEPA has informed the ECCLR Committee that it is to undertake “an investigative survey on azamethiphos” this year9, but the ECCLR has already concluded that it “is not convinced SEPA (or any other agency) is effectively monitoring the environmental impact of salmon fisheries…” and that “the Committee is supportive of aquaculture, but further development and expansion must be on the basis of a precautionary approach…”.

SEPA should not now permit an increase in biomass that might result in greater use of azamethiphos at Gob Na Hoe, but should act in a precautionary manner and, at the very least, wait until the outcome of its work on azamethiphos, as already planned this year, is known.

Sea lice and damage to wild salmonid populations

Both emamectin and azamethiphos are still used very widely by the applicant to control sea lice on its fish farms at their currently permitted biomasses. However, there is clear evidence that fish farmers do not succeed in controlling sea lice on farms, to the detriment of wild salmon and sea-trout populations outside the cages.

The Gob Na Hoe fish farm is sited in the Skye and Small Islands South region for which aggregated sea lice data has been reported by the SSPO in three-monthly Fish Health Management Reports since 2013. The data on aggregated sea lice number of fish farms shows that there has been a serious sea lice issue in this region, in each of the last three production cycles.

Fish farms in both these regions have suffered from repeated inability to control sea lice numbers over the last three production cycles, as the graph below, drawn up using SSPO data demonstrates.

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Against the biomass at Gob Na Hoe only, there is a correlation between increasing biomass at Gob Na Hoe and regional sea lice levels, as shown below:

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Note that the ECCLR Committee has just concluded that it “considers there should be a mandatory requirement to keep sea lice levels within those identified in the Code of Good Practice”, in other words, lice levels should be below the green line on the graphs above.

This region is clearly some way away from achieving that requirement. SEPA should also note that Marine Scotland Science has repeatedly stated “that adherence to the suggested criteria for treatment of sea lice stipulated in the industry CoGP may not necessarily prevent release of substantial numbers of lice from aquaculture installations”.

The Fish Health Inspectorate has made a number if inspections of Gob Na Hoe over recent years10.

The FHI reported in December 2014 that “sea lice numbers increased above the suggestedcriteria for treatment in Sept 2014, treatments have reduced numbers but not below this level”.

In March 2015, the FHI recorded that “sea lice numbers have been elevated on site and increasing from September 2014 to a peak in December of 15 adult leps.
Numbers had been controlled with hydrogen peroxide bath treatments up to the end of February however numbers have been increasing through March to an average of 10.06 adult females on the 10 March.
With regards to parasites it was observed that sea lice numbers have been elevated since September 2014 with treatments on-going therefore the site has been recommended for an enhanced inspection and this will be conducted in due course”.

The FHI carried out that enhanced inspection in September 2016.

The FHI inspected the farm again in October 2016 and still recorded that “lice levels at site currently 1.78 average adult female”.

The FHI inspected again in May 2017 and noted:
Some targeted treatments carried out. Mixture of tarp and wellboat treatments
May 2017 – Combined Salmosan/H202 treatment site
March 2017 – AMX/H202 2 cages
March 2017 – Salmosan H202 2 cages
January 2017 Slice
February 2017 – Salmosan site
December 2016 – AMX/Salmosan 3 cages
November 2016 – Salmosan/site
September 2016 – Salmosan site
August 2016 – Slice
July 2016 – H202
February into March 2016 – Slice
Lice levels 1.25 AAF for site at last count 14/5/17
AAF peaking at 15.6 on 9/11/16 – levels had been above the reporting threshold after 25/10/16 but no reports until week 1 of 2017”

Added to this, the FHI has released some data concerning Gob Na Hoe, after being ordered to do so as a result of the Decision of the Scottish Information Commissioner in 2017 secured by S&TCS11. As the FHI implements the Scottish Government’s new sea lice management policy for Scottish salmon farming, it requires all salmon farmers to develop site specific escalation action plans to be implemented when sea lice levels rise above 3.0 average female lice per farmed fish. When levels exceeded 8.0 average female adult lice, the new policy was to result in enforcement action by Marine Scotland, including the potential to require reduction in biomass. This new policy was outlined to NASCO in June

Of course, as the levels at which action is indicated under the new policy are set so high, considerably in excess of those used in other salmon farming countries, or the CoGP thresholds, this policy does little to meet the international goal for NASCO members, that 100% of farms are to have effective sea lice management such that there is no increase in sea lice loads or lice-induced mortality of wild salmonids attributable to the farms.

Nevertheless, the FHI data has confirmed that, in 2017, the Gob Na Hoe fish farm breached the new 3 adult female lice per farmed fish trigger level for a staggering 24 consecutive weeks in 2016 into 2017, and then for a further period of 4 more weeks, exceeding 8 adult female lice on at least 5 separate occasions:

Capture L 5

Capture L 6

The sea lice produced by the Gob Na Hoe fish farm in the previous production cycles will have severely damaged wild salmon and sea trout populations. Together with more sea lice larvae produced by nearby farms, any lice produced by Gob Na Hoe would have been a major threat to wild salmonids near that farm, and indeed several tens of kilometres away.

Generally, sea lice larvae produced in huge numbers by fish farms damage wild salmonids. A 2018 review, commissioned by S&TCS from the Norwegian Institute for Nature Research(NINA)12, examined all available research on the impact of sea lice, and concluded that “the combined knowledge from scientific studies provides evidence of a general and pervasive negative effect of salmon lice on salmonid populations in intensively farmed areas of Ireland, Norway and Scotland. … Levels of additional mortality by salmon lice as indicated in several scientific studies may result in salmon stocks not achieving river specific conservation limits and, if sustained over time, could result in significant cumulative reductions in adult salmon recruitment.”

Worryingly, the SAMS Report for the ECCLR Committee, also published this year, has concluded that “the main treatment methods used in Scotland are experiencing reduced efficacy in dealing with sea lice on farms. New techniques are being applied, although the long-term success of these is uncertain. The legislative and voluntary frameworks that underpin the management of lice levels on farms are not transparent. They appear neither to be succeeding in controlling sea lice, nor capable of addressing the environmental effects of the lice.”13

The data is also now showing clearly that wild salmon in the ‘aquaculture zone’ of the Scottish west coast are in greater jeopardy than populations elsewhere. The percentage probability of Scottish rivers reaching salmon Conservation Limits (five-year average 2012-2016), shown using Marine Scotland Science data from the conservation assessments for 2018 by river and assessment group14, indicates a clear impact on the conservation of wild Atlantic salmon in the ‘aquaculture zone’ of the west coast of Scotland, with Atlantic salmon populations in rivers in the aquaculture zone far less likely to be reaching Conservation Limits, just as the NINA report above suggests.

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SEPA’s legal position on sea lice

Despite SEPA’s formal position that the control of sea lice does not fall under not their statutory functions, given the above, the impact outside of a fish farm of sea lice produced on a farm is not something that SEPA, nor any other relevant public authority, can lawfully ignore or ‘buck-pass’ away.

As the ECCLR Report noted, at paragraph 197 of its Report, “wild salmon and trout are PMFs and as such are considered to be marine nature conservation priorities in Scottish waters”. In his very recent letter to the Convenor of the ECCLR, the Chief Executive of SEPA has confirmed that “we are responsible for assessing the risk posed to PMFs, MPAs and SACs when considering proposals for new marine cage fish farms or proposal to change the operation of existing farms”15.

Pursuant to the Nature Conservation (Scotland) Act 2004, SEPA has a duty to further the conservation of biodiversity in exercising its functions. That must include furthering the conservation of PMFs such as wild salmon and sea trout.

SEPA’s own Fish Farm Manual, published in 2005, indicates that SEPA appreciates it has a role here, stating variously that “in order to better protect wild salmonid stocks however, SEPA has adopted a Limiting Factor approach to consenting marine caged fish farms. SEPA may, in determining biomass limits for sites where proximity to important wild stocks is considered as a significant issue, impose a biomass limit equivalent to that biomass which can be effectively treated for sea lice infestations using an authorised sea lice medicine” and that, when setting consent limits, “in certain instances to protect important wild salmonid stocks, SEPA will limit the biomass to that which can be treated at the site using an authorised sea lice medicine.”

SEPA also has duties with respect to the Water Framework Directive (WFD). Section 2 of the Water Environment and Water Services (Scotland) Act 2003 requires SEPA to exercise its functions under the relevant enactments so as to secure compliance with the requirements of WFD. The aim of WFD is to ensure all water bodies achieve ‘good ecological status’. That status is assessed as against various quality elements.

Annex V of WFD requires the assessment of the fish fauna quality element of water bodies considering the composition, abundance, and the presence and/or absence of disturbance-sensitive taxa for rivers and transitional waters. In short, the ecological status of rivers in Scotland is assessed against wild salmonid populations.

SEPA must therefore exercise their functions, including those relating to the permitting of fish farms, both to avoid the deterioration of, and to restore wild salmonids populations. Given that, it should be using its powers to regulate fish farms under CAR also to control the impact of fish farm-derived sea lice on wild salmonids.


SEPA will be well aware of the many other conclusions of the recent report of the ECCLR Committee, which calls into question the regulatory effort of all relevant Scottish public authorities, including SEPA, to control fish farm impacts.

The ECCLR Committee’s over-arching conclusion was that “further development and
expansion must be on the basis of a precautionary approach and must be based on
resolving the environmental problems. The status quo is not an option” [the ECCLR Committee’s own emphasis]. The ECCLR Report also says that “the current consenting and regulatory framework, including the approach to sanctions and enforcement, is inadequate to address the environmental issues. The Committee is not convinced the sector is being regulated sufficiently, or regulated sufficiently effectively. This needs to be addressed urgently because further expansion must be on an environmentally sustainable basis” and that “If the current issues are not addressed this expansion will be unsustainable and may cause irrecoverable damage to the environment”.

The ECCLR has therefore concluded that (1) further expansion must be sustainable and that(2) unless current issues are addressed, (3) any expansion will be unsustainable and may cause irrecoverable damage etc.

In conclusion, given the ECCLR Committee’s conclusions, SEPA’s legal position and the evidence on this particular farm, as presented above, S&TCS believes that SEPA cannot now permit an increase in the biomass at Gob Na Hoe.

On the contrary, given the appalling and prolonged record with respect to sea lice at this farm, SEPA should now use its powers under CAR to review and lower the current permitted biomass at this and potentially other farms in the Skye and Small Isles South region.

Yours sincerely

Guy Linley-Adams

1 SEPA (2011) Attachment XV Marine Cage Fish Farm CAR Licence Review published 1 April 2011 version 1.0
2 https://www.sepa.org.uk/media/114940/fish-farm-manual-attachment-15.pdf
3 Wilding TA and Black KD (2015) “A statistical analysis of sea-lice medicine use and benthic monitoring at Scottish marine salmon farms (2002 to 2014)” in SARF098 “Towards Understanding of the Environmental Impact of a Sea Lice Medicine – the PAMP suite”.
4 SEPA (2016) Recommendations to SEPA AMT from Andrew J Rosie, Head of Operations: North, Chair ASMG, Douglas Sinclair, Lead Aquaculture Specialist and Calum MacDonald, Executive Director, (Operations Portfolio) 12th February 2016
6 Decision 043/2018 SEPA Information relating to the use of sea lice medicine, 26 Mar 2018, Decision 013/2018
SEPA Correspondence with Marine Scotland, 31 Jan 2018, Decision 010/2018 SEPA Report on the
environmental impact of sea lice medicine 29 Jan 2018, Decision 199/2017 SEPA Information concerning sea
lice medicine 30 Nov 2017 https://www.itspublicknowledge.info/ApplicationsandDecisions/Decisions/Decision_Listing.aspx
9Letter from Terry A’Hearn to Graeme Dey MSP, Convenor, ECCLR Committee 28 March 2018
10 http://www.gov.scot/Topics/marine/Fish-Shellfish/FHI/CaseInformation
11 Decision 142/2017: Salmon and Trout Conservation Scotland and the Scottish Ministers Control and reduction of sea lice on fish farms Reference No: 201700453 and 201700777 Decision Date: 4 September 2017 https://www.itspublicknowledge.info/uploadedFiles/Decision142-2017.pdf
12 Thorstad, E.B. & Finstad, B. 2018. Impacts of salmon lice emanating from salmon farms on wild Atlantic salmon and sea trout. NINA Report 1449: 1-22. Trondheim, Norway, January 2018 at https://brage.bibsys.no/xmlui/handle/11250/2475746
13 Para 2.1.4 at page 15
14 An explanation of Conservation Limits, and the probability of rivers meeting them, is available here:
15 Letter, Terry A’Hearn CEO SEPA to Graeme Dey MSP Convenor ECCLR Committee, 28th March 2018



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