7 minute read
Containment
The threat of seal attacks has been a major headache for fish farmers
In January, salmon farmers in
Scotland sounded the alarm over predation attacks by seals, following a major incident at a Skye-based farm in which 52,000 juvenile salmon were lost.
The Scottish Salmon Producers Organisation (SSPO, now renamed Salmon Scotland) says that from May 2019 to May 2020 more than half a million farmed salmon in Scotland died as a result of seal attacks, either directly from a physical attack or indirectly from stress. New regulations have also limited the action farmers can take to control seal predation.
The Skye attack, on 31 December, was at a farm based at Portree and managed by The Scottish Salmon Company. The site was due to have new “seal proof” netting technology installed by the end of January.
A spokesperson for The Scottish Salmon Company said: “Our Portree site has recently been subject to persistent attacks from a large group of seals which, despite our best eff orts, caused signifi cant damage to one of our nets. Our staff moved quickly to repair this damage but unfortunately a number of fi sh escaped… we take these matters extremely seriously and have invested substantially in measures to ensure containment and deal with predators like seals.”
A change in regulations has meant that, as of the end of January 2021, farmers no longer have recourse to lethal controls to deal with seals. There are also restrictions coming in regarding what types of acoustic deterrent devices (ADDs) or “seal scarers” may be used. A review into the use of ADDs, announced in July last year, is ongoing.
Tavish Scott, Chief Executive of the SSPO said: “Salmon farms and seals
This page from top: Ace Aquatec’s RT1; sea lion eating salmon Opposite: Seals in salmon pen after biting through top bird protection netting
can co-exist quite happily in the marine environment. Seals can however infl ict vicious and widespread damage on salmon farms, killing signifi cant numbers of fi sh in each attack. That is what has happened to The Scottish Salmon Company farm in Skye. The seals ripped open the nets and killed many fi sh, with others escaping. “This distressing incident shows that our farmers need access to a range of eff ective tools and measures to deter seal attacks and protect their livestock. Our sector is continuing to make substantial investments in new technologies and management methods which follow government regulations. Our approach is consistent with the clear commitments our member companies have made.”
In the 12 months to May 2020, Scottish salmon farming sector investment into preventing predator attacks was £8.4m. Investment into new generation anti-predator nets accounted for £5.3m. In March, the SSPO/Salmon Scotland announced that none of its members was now using any form of ADD that had been shown to disturb protected marine mammals. Only acoustic deterrent devices (ADDs) that comply with both the requirements of Marine Scotland and US regulations were being used. Anne Anderson, then Director of Sustainability for the SSPO said: “Scottish salmon farmers are not using any acoustic deterrent devices that may have been considered to endanger cetaceans such as dolphins, porpoises and whales. All devices the sector does not have total confi dence in, with regards to the harming of protected species, have been turned off and removed from the marine environment.
“It is critical however that farmers have deterrents available to protect their livestock from seal predation. As such the Scottish salmon farming sector is committed to, where necessary, only using acoustic devices that have been scientifi cally proven to be compliant with the US Marine Mammals Protection Act (MMPA).” Later in the year, Salmon Scotland members went even further, agreeing to switch off all ADDs until Marine Scotland can clarify its position on licensing them – although Fish Farmer understands that a minority of members included the caveat that they would use them in extreme circumstances. Also in March, Fisheries Management Scotland (FMS) said that it estimated as many as 3,000 escaped salmon from Mowi’s Carradale farm site had found their way into rivers in Scotland and northern England. Carradale was hit hard by Storm Ellen in August 2020, and it is believed just over 48,000 fi sh escape. While FMS said the majority had not made it into freshwater, reports from anglers suggested that a minority had done so. Following the Carradale incident, FMS, Marine Scotland Science and
Mowi have been working together on a genetic monitoring project, to see what impact the escapes have had on the stock of wild salmon.
In August
we reported on a cull of sea lions in the US state of Oregon. The US Marine Mammal Protection Act normally forbids the killing of marine mammals – and because of the economic sanctions included in the act, it eff ectively applies to any country seeking to export seafood to the US – but a “take permit” can be granted under exceptional circumstances.
In this case, the cull was authorised in order to protect wild salmon in Oregon, since it is possible to grant a take permit in order to protect another endangered species.
This page from top: Mass salmon mortalities following seal attack; OTAQ’s SealFence
In November, Salmon Scotland estimated that more than one million farm-raised salmon in Scotland will have been killed by seals in the two years to the end of 2021.
Seal attacks cost salmon farmers an average of £12m a year in lost fi sh, the organisation said.
Tavish Scott, Chief Executive of Salmon Scotland, said seal predation was getting worse and he urged government ministers to sit down with sector leaders to discuss possible solutions. He said: “There is no easy fi x but we need a dialogue with ministers – and the leaders of other sectors affected – to fi nd ways of tackling what has become an increasingly serious issue for our members.” The fi gures released by Salmon Scotland show that in 2020, 516,443 fi sh were killed directly in seal attacks (with many hundreds of thousands more so stressed they died later).
In the eight months to the end of August 2021, a further 347,917 salmon were killed directly by seals, taking the total since January 2020 to 864,360. With four months left in 2021 and with seal attacks peaking traditionally in the winter, the total is due to pass one million well before Christmas.
The salmon killed by seals would have fetched a market price of £12,253,743 in 2020 and a further £8,436,987 in the eight months of 2021 to end of August, adding up to a total lost revenue of £20,690,730.
Scotland has 210 active salmon farms, of which about 70% will be stocked at any one time. This means that on average, 2,792 salmon were lost per farm (with a lost harvest revenue of £67,696) in 2020 and a further 1,955 fi sh (with an expected harvest revenue of £47,399) in the fi rst eight months of 2021.
Until the start of 2021, salmon farmers could shoot seals as a last resort and a small number, about 50, were shot every year to protect stocks. This power has since been removed by Scottish Government legislation.
Salmon Scotland argues that farmers have a statutory duty to protect their stock but many feel they are powerless to do anything about seals, which are a protected species, as they now can neither despatch the predators nor scare them away using ADDs.
