Q&A: Salmon lice and pesticide use

BBC Scotland reporter Stephen Magee asked a Scottish government spokesman to explain its position on the use of chemicals in combating sea lice.

Here are the key points they discussed:

There is evidence from Sepa (Scottish Environment Protection Agency) of increased use of pesticides (and the use of an increased range of pesticides) on Scottish farms. Is this a matter of concern? What is the explanation for the increase?

• The reasons for increased use of sea lice medicines are quite complex and almost certainly due to a number of factors. In order to be certain of the reasons, much more information would be required on where, when and how use has been made of sea louse medicines but in general, increasing use is not in itself necessarily a matter for concern. Increasing use is linked to increased production and may also be associated with the development of more formal strategies of lice control in recent years such as that inspired by the signing of Area Management Agreements with wild fish bodies. It may also be associated with recognition by industry of the desirability of adopting integrated sea lice management practices, rotating medicine use to avoid or slow the development of resistance.

• The increased range of products arises because of the introduction of the new medicine AMX, containing Deltamethrin in 2008 and the reintroduction of Salmosan, containing azamethiphos, in 2007. The addition of these products allows vets more choice in the available medicines, again helping to avoid repetitive use of a small number of products which may promote the development of resistance. Comparisons of gross amounts of medicine aren't always informative as the amount of each product used to administer a dose to the fish varies significantly. For example, AMX and Salmosan are administered by bathing fish in contained water rather than through feeding. These treatments use more medicine than in-feed and, therefore, the increased overall use of medicines also partly reflects the method of treatment.

• The rise in use therefore is due to a range of issues but might be taken to indicate responsible use of medicinal products and a desire to control louse infestations. The most important point to note is that SEPA imposes limitations on the use of these substances derived to ensure environmental protection. Increased use of these medicines within these limits should not cause undue environmental concern.

Is there any more to say about the Sea Lice Audit?

The review of the audit methodology is now complete and the subsequent guidance has been updated. The regime for conducting enhanced inspections regarding sea lice will commence in January 2011. The inspection and audit process will be measured in their ability to deliver meaningful outcomes with regard to the control of parasites.

I interviewed a former government scientist, Andy Walker, about the use of scientific evidence. He feels that negative news about the fish farming industry - and sea lice - has been ignored by policy makers. How would you respond?

• This is unfair and does not stand up to scrutiny. Marine Scotland policy makers and scientists continue to work hard to better the understanding of the impact of aquaculture on wild salmonids at the population level.

• For example, let's consider this in the context of developments over the past couple of years, particularly since the publication of "A Fresh Start: The Renewed Strategic Framework for Scottish Aquaculture" in May 2009. The Scottish Government has taken considerable steps to protect wild salmon and continues to do so. These were set out in Roseanna Cunningham's (Minister for Environment and Climate Change) recent responses to the Scottish Parliament Public Petitions Committee and available on the Scottish Parliament website at:

• A number of Working groups flow from the Fresh Start. For example, the Healthier Fish and Shellfish Working Group was established to look specifically at the issues of fish health and sea lice. The group is chaired by Professor Randolph Richards, Institute of Aquaculture, Stirling University and includes representatives from:

• Industry (trout and salmon)

• Wild fish

• The Scottish Environment Protection Agency (SEPA)

• Scottish Government Veterinary Advisors

• Marine Scotland

• This group has been tasked with making recommendations for the conditions to be attached to finfish business authorisations under the Aquatic Animal Health (Scotland) Regulations 2009 to ensure delivery of single year class stocking of sites, sea lice treatment and fallowing of appropriate scale management areas.

• In addition the group has made recommendations on the form of a national system for the collection of sea lice and mortality data to underpin future effective control measures. Ministers are considering the recommendations which will be discussed at the next meeting of the Ministerial Group on Aquaculture in February 2011.

• We have also signed a Memorandum Of Understanding agreement with Norway to share best practice and expertise on containment and sea lice. The first meeting of this Joint Committee for Bilateral Co-operation on Aquaculture will be held in Edinburgh in March 2011.

• Finally, Marine Scotland Science itself has a strong research program in place, in relation to sea-lice and containment, one of the aims of which is to better understand the interactions between fish farms, sea lice and salmonids.

Wild fish groups seem increasingly negative about co-operation with the industry. They are now telling me they are actively investigating court action against producers over sea lice. How would you view this?

This is a matter for those groups. We would prefer all interested parties to work together towards common goals and there are arrangements in place for this to happen.

Campaigners have obtained Fish Health Inspectorate Reports from 2009 and some of 2010. They are still being analysed. But an initial look at them shows some farms do have levels of lice above the trigger levels, and some have reported resistance to SLICE (a chemical used to control lice numbers). Is this a matter of concern for the Scottish government?

The aquaculture industry should aim to reduce levels of sea lice that have breached the advised trigger levels for treatment within the industries Code of Good Practice, and should seek veterinary advice regarding their sea lice management strategies to enable them to do this. There is an obligation to report any suspected lack of expected efficacy to the Veterinary Medicines Directorate. The efficacy of an appropriately administered and managed integrated sea lice management strategy must be considered as a whole. As part of an integrated sea lice management strategy the industry should undertake bioassays to determine the sensitivity of sea lice to treatments. The results of these tests should be used to determine the most effective available treatment to be utilised during the production cycle.

The risk of resistance is an issue which creates a challenge for the control of sea lice in most countries where Atlantic salmon are farmed. Within Scotland this is being tackled through scientific research to inform best practice for controls and the adoption of these by fish farmers. As previously mentioned in answer to question 3, the Healthier Fish Working Group have reported recommendations around sea lice control. We are benefiting from the Memorandum of Understanding with Norway and the Multi-Nation Sea lice initiative through the sharing of best practise, expertise and scientific knowledge. Scotland is also collaborating with the Norwegian sea lice research centre.


The publishing proposals for the audit (now called enhanced inspection) include:

Reporting on the various sections separately - e.g. inspection of sea lice records; inspection of records relating to treatment; inspection of site stock etc. etc.

Results of the outcome of each section of the inspection will be reported as either: Meets the requirement of best practice; Minor issues raised - no further action required, or; Recommendations made for improvement

We will not be routinely collecting farm sea lice data and therefore such information will not be part of any publication.

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