THE welfare standards in salmon farming in Scotland are currently very high and there is no reason to believe these will slip if the industry expands, a committee in Holyrood heard this morning.
Dr Adam Hughes, from the Oban based Scottish Association for Marine Science (SAMS), was part of a panel answering questions on the environmental impact of salmon farming.
They were asked by Mark Ruskell, the Green MSP, about the high level of mortalities in the past year and how the proposed expansion of the industry would affect fish welfare.
Hughes said the recent mortalities were a one in five or even a one in ten-year high, and that there are environmental impacts in any form of food production; it is up to society to decide what is acceptable and what is not.
The Environment, Climate Change and Land Reform (ECCLR) Committee had earlier commissioned a report by SAMS to review the literature on the environmental impacts of salmon farming in Scotland, the scale of the impacts and approaches to mitigating the impacts.
Today it took evidence from SAMS personnel, including Dr Hughes, Professor Paul Tett and Professor Nick Owens. Also on the panel was Professor Eric Verspoor from the Rivers and Lochs Institute and the University of the Highlands and Islands.
The ECCLR committee’s inquiry was undertaken in advance of the Rural Economy and Connectivity (REC) Committee’s forthcoming inquiry into aquaculture in Scotland, expected to take place after Easter.
The committee, chaired by the SNP MSP for Angus South, Graeme Dey, heard views on alternative production methods, such as closed containment, which may afford greater control over biosecurity.
However, the MSPS were told that while there had long been a focus on research into recirculating aquaculture systems (RAS), and the technology had advanced, the costs are much higher than in conventional net pen farming.
Also, societal perception surveys suggest that consumers believe open sea pens are more natural and environmentally friendly, said Hughes. There were also welfare implications because of the likely increase in stocking densities in closed containment production.
Looking at the impact of sea lice on wild salmon, Professor Verspoor said an excessive sea lice burden on wild stocks can have a negative effect on their survival.
However, whether this is a concern in any given location is another question; ‘not all salmon have the same journey’, with some rivers near salmon farms reporting historically high stocks levels.
Claudia Beamish, the Labour list MSP for South Scotland, questioned the accessibility of data from farms.
Professor Verspoor agreed that, in principle, transparency was desirable but warned that ‘there is misuse of this information on both sides of the debate’ and that ‘science takes a long time to crunch the numbers’.
On the subject of the discharge of waste nutrients, John Scott, the Conservative MSP for Ayr, asked what effect the breakdown of emamectin benzoate, used in some sea lice treatments, had on other species.
Professor Tett said it was very difficult to get evidence from the seabed as most monitoring is not sensitive enough. He suggested that a longer-term investigation of sea lochs was needed.
‘One conclusion that I’ve come to is that there is no standard sea loch,’ he said, adding that each farmer should understand the local conditions of their farms.
As far as other chemicals go, he said there is comparatively little use of antibiotics in Scotland now as vaccines seem to have done their job.
And anti-fouling chemicals, such as those used on nets (as well as by other marine users, inclduing sailing boats), had undergone a big change following the discovery of the harmful effects of Tributyltin (TBT) on molluscs. Less harmful chemicals, such as copper and zinc, are now used.
The committee also questioned the panel on a review by the Scottish Environment Protection Agency (Sepa) into biomass consenting, and the advantages of ‘adaptive management’.
The committee will next take evidence, on February 6, from the Scottish Salmon Producers Organisation, Scottish Environment Link, Friends of the Sound of Jura, Loch Duart, Sepa, the Scottish government and Highland Council.
Picture: Dr Adam Hughes from SAMS