A salmon farm off the West Coast of Scotland near Oban. Pictures by Bill Heaney
Investigation by Rob Edwards in The Ferret
Noise alarms used by the salmon farming industry to scare away seals could damage the hearing of whales, dolphins and porpoises, according to the Scottish Government’s wildlife agency.
Documents obtained under freedom of information law show that Scottish Natural Heritage has been pressing fish farms around the coast to reduce and phase out the use of “acoustic deterrent devices” (ADDs), to protect marine mammals.
Proposals to ban the use of ADDs are due to be considered at Holyrood when MSPs debate the final stage of an animals bill. There are fears that fish farms will deploy more of the devices because the shooting of seals is to be outlawed.
Campaigners claim ADDs are illegal under European environmental law, and should be immediately banned. Fish farm companies, however, insist that they need ADDs to help stop seals from killing half a million caged salmon a year.
The Ferret reported on 2 June that the Scottish Government was planning to ban seal shooting in order to save Scotland’s £180 million business exporting farmed salmon to the US. The number of seals being shot by salmon farms has doubled between 2019 and 2020.
Ministers have lodged amendments prohibiting shooting to the Animals and Wildlife Bill to be debated by the Scottish Parliament on 17 June. But the Scottish Greens have also tabled an amendment seeking to ban ADDs, which they describe as “sonic torture devices”.
Now Scottish Natural Heritage (SNH) has released 15 files containing 2,800 pages of internal reports and correspondence about ADDs. They show that SNH has repeatedly expressed concerns about the impact on cetaceans, including whales, dolphins and porpoises.
In 2017 SNH was asked for “formal statutory advice” on ADDs by the Scottish Government’s Marine Scotland agency. “There is sufficient evidence, both empirical and modelled, to show that ADDs can cause disturbance and displacement of cetaceans,” SNH said in response.
“There is sound scientific evidence to expect that hearing damage, stress and masking (hiding other sounds) may also occur but these are difficult to demonstrate empirically and would require further assessment. Accordingly we believe there is a strong case for managing ADD deployment and use.”
SNH listed 12 studies that had suggested that ADDs disturb harbour porpoises, minke whales, killer whales and white-sided dolphins. “ADDs emit frequencies within the hearing range of cetaceans,” SNH concluded.
The devices “have the potential to cause injury”, it added. “Current legislative protection requires a precautionary approach where a risk cannot be discounted beyond scientific doubt.”
In January 2020 SNH raised concerns about the use of ADDs at three salmon farms in Argyll. In November 2019 SNH warned Highland Council that ADDs at a proposed fish farm off the Isle of Skye were “likely to have a significant effect on harbour porpoises”.
The released documents show that SNH also repeatedly criticised the use of ADDs at fish farms in May, June, July, August and September 2019. In 2018 SNH described an online claim that it backed one particular acoustic device as “inaccurate and misleading” and demanded it be deleted.
Seal scarers ‘should be banned’
The Scottish Greens welcomed SNH’s moves. “This is clear confirmation from Scottish Natural Heritage that these devices cause considerable harm to marine life,” said the party’s environment spokesperson, Mark Ruskell MSP.
He pointed out that there were “far more humane alternatives” such as stronger nets designed to prevent seals from eating caged salmon. “I hope this revelation will convince MSPs to back my amendment to extend the seal culling ban to include these torture devices,” he told The Ferret.
“Otherwise it will be clear that market forces have driven the legislation, not real concerns over animal welfare.”
The SNH documents were obtained by the anti-fish farming campaigner, Don Staniford, from Scottish Salmon Watch. “Salmon farmers are caught between the devil of killing seals and the deep blue sea of noisy acoustic deterrent devices which harm cetaceans,” he said.
“Noisy ADDs need to be turned off completely not just turned down. Instead of protecting seals and cetaceans, Marine Scotland has been desperately trying to shield the salmon farming industry from the added costs of anti-predator nets.”
He added: “To comply with EU and US legislation, there must be an immediate and unconditional ban on the use of ADDs on salmon farms. If salmon farms cannot avoid harming marine life then they should move out of the way.”
David Ainsley, a marine biologist who runs wildlife watching boat trips near Oban, has started a petition to ban ADDs. To date it has been signed by over 25,000 people.
He said: “Just now seals, dolphins and porpoises are having babies, but they are being driven out of safe inshore nursery areas by acoustic deterrent devices, which are unnecessary because double nets stop seal predation without harming marine mammals.”
He described the noise from ADDs as “staggeringly high” and also criticised Marine Scotland. “Scottish law prohibits disturbance or injury to any porpoise, dolphin or whale but Marine Scotland, the regulators, are not enforcing the law,” he said.
Scottish Natural Heritage stood by its advice that ADDs could disturb cetaceans. “We note the proposed changes to the seal licensing system and understand and support the need to strengthen seal protection,” said the agency’s head of sustainable coasts and seas, Cathy Tilbrook.
“We would not wish the removal of seal licensing provisions to lead to an increase in use of ADDs as a response to seal predation risks, and we will continue to work closely with Marine Scotland and industry to seek effective regulation of use of ADDs and the development and implementation of alternative solutions which avoid risks to other marine wildlife.”
The Scottish Salmon Producers Organisation, which represents fish farm companies, highlighted the damage that seals could do. “Scotland’s salmon farmers lose more than 500,000 fish every year to seal attacks,” said the organisation’s spokesperson, Hamish Macdonnell.
“To prevent predation and protect the health and welfare of their fish they need to be able to access a broad range of measures, including acoustic devices.”
A Scottish Government spokesperson said: “We are giving all amendments lodged under the Animals and Wildlife Bill careful consideration, and we will outline our position at the stage three debate.”
The Scottish Greens have also introduced amendments for discussion by MSPs on 17 June to try to stop gamekeepers shooting mountain hares and farmers shooting beavers.