New evidence fuels Salmon & Trout Association demand for Scottish Salmon Producers to retract dismissal of sea lice impact on wild salmon

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The Salmon and Trout Association Scotland is demanding that the Scottish Salmon Producers’ Organisation [SSPO] retract its February 2013 statement dismissing the impact of sea lice on wild salmon.

The basis for the demand is a new scientific paper which shows that SSPO relied on a study that was fundamentally flawed. A summary of the paper is available at the foot of this article.

Back in February this year the Scottish Salmon Producers’ Organisation issued a triumphant announcement that ‘the average mortality in wild salmon due to sea lice is tiny, less than 1%’.

The scientific study in Ireland, which SSPO used to justify its controversial position, has now been exposed as fundamentally flawed.

In January Dr Dave Jackson of the Marine Institute in Ireland had a paper published in the Journal of Fish Diseases, concluding that there was a negligible risk (1%) to migrating salmon from sea lice.

The paper apparently examined 350,000 fish, released into eight different rivers in 28 separate experiments over nine years.

This paper was seized on by SSPO as a silver bullet dismissing once and for all that sea lice emanating from salmon farms have any meaningful impact on wild salmon numbers.

SSPO issued a news release on 1st February 2013  entitled Sea lice threat to wild salmon ‘no basis in scientific fact’, finds new study, in which Professor Phil Thomas, Chairman of SSPO, trumpeted: ‘I welcome the findings which are rigorous, definitive and unequivocal…..’

The findings in question were certainly unequivocal but due scrutiny has demonstrated that ‘rigorous’ and ‘definitive’ are, shall we say, rather over enthusiastic.

Last week the very same Journal of Fish Diseases published another paper [summary attached] by Krkošek et al – international experts on sea lice and methodology from Scotland, Norway and Canada.

This paper demolished the Jackson paper and in particular pointed to fundamental errors in Jackson’s methodology:

  • Data differences from year to year were not treated appropriately.
  • Averages regarding the survival of fish were used incorrectly.
  • Grave mistakes in measuring control and treatment groups, leading to wide inaccuracies.

The new paper re-analyses the original data and shows that the impact of sea lice on wild salmon causes a far higher loss (34%) of those returning to Irish rivers than the 1% loss deduced in the Jackson paper.

This is no minor discrepancy.

Hughie Campbell Adamson, Chairman of S&TA(S), says: ‘In light of what has now been clarified by Krkošek and his fellow experts in this field, one would hope that SSPO, if it is to retain any credibility as the representative trade body for the salmon farming industry in Scotland, will have the integrity to withdraw formally the press release it issued in February in which the SSPO Chairman Professor Phil Thomas made his inflammatory and ill-considered statement.

‘It is now clear that the paper SSPO and Professor Thomas relied on to justify their position is simply a travesty and indeed, given the flaws which have now been exposed, should never have been published.’

Guy Linley-Adams, Solicitor to the S&TA Aquaculture Campaign, says: ‘It is now time for SSPO to stop hiding behind a smokescreen of dubious science and acknowledge that sea lice spreading out from salmon farms can have a devastating impact on the marine survival of both salmon and sea trout. In the short term, those farms sited in the mouths of salmonid river systems must be relocated away.

‘The only long-term solution is, of course, for all salmon farm production to move to closed containment units, thus creating a biological barrier to prevent the transfer of parasites from farmed fish to wild fish.’

It is time now to hear from Fisheries Secretary, Richard Lochhead and from Environment Minister Paul Wheelhouse on this matter.

The shelter Scottish Ministers have offered to the Scottish Salmon Producers Organisation in flagrant defiance of the evidence of a spectrum of unacceptable practices within the industry is a matter of profound concern.