They look like pristine, unpolluted beauty spots – but in fact they are contaminated with toxic pesticides.
The sea lochs that line Scotland’s north west coast, famed for their natural splendour, are polluted by poisonous chemicals used by fish farms, surveys by the Scottish government’s green watchdog have revealed.
The sediments in nine sea lochs – all those surveyed by the Scottish Environment Protection Agency (Sepa) – have been found to contain detectable levels of pesticides widely used to kill the sea lice that eat caged salmon.
Although Sepa stresses that the levels are mostly low, environmentalists, anglers and creel fishers condemn the contamination as unacceptable. And they claim that the chemicals could be damaging marine wildlife.
Sepa has released the results of its latest surveys of sea lochs for four pesticides: teflubenzuron, diflubenzuron, emamectin and ivermectin. They are all chemical compounds for treating salmon infested with sea lice, though land managers can also use them.
Traces of emamectin were found in sediment at all nine lochs tested in 2008 and 2009, including Loch Linnhe, Loch Ewe, Loch Nevis, Loch Fyne and lochs around Skye, Mull and the Summer Isles. Teflubenzuron was found at six lochs, and diflubenzuron at four (see table below).
Sepa pointed out that although the chemicals were known to be used at fish farms, they could also be applied by foresters and land farmers trying to combat various pests. Further investigations were required to pinpoint the exact sources of the contamination, the watchdog argued.
Though a few of the samples breached environmental standards, there was a “low risk of possible impacts”, said Sepa’s fish farming expert, Douglas Sinclair. “These surveys have provided Sepa with important information on chemicals in the marine environment.”
He added: “Sepa has already instigated a programme of site visits to carry out sampling and inspections to check for chemical use in some of the areas covered by these studies. Future monitoring programmes may be designed in a different way to provide more definitive evidence of the source of any residues.”
Sepa was targeting 40 of Scotland’s most polluting fish farms in an effort to clean them up. “As well as tackling poor performers using this action plan approach, Sepa will undertake formal enforcement action where offences or significant environmental harm have occurred,” said Sinclair.
Others expressed more concern. “Scotland trades on its beautiful and pristine environment but the truth is we are still letting poisons contaminate our sea lochs,” said Dr Richard Dixon, the director of WWF Scotland.
“International agreements quite rightly require us to eliminate discharges of toxic chemicals to the sea over the next decade. Fish farmers, farmers and the forestry industry have made progress but they all need to do more.”
According to Guy Linley-Adams, a solicitor who works with the Salmon and Trout Association, representing anglers, most people would think that West Highland lochs are free from pollution. “The truth is somewhat different,” he told the Sunday Herald.
“Although Sepa suggests it cannot be sure where these residues come from, I would just observe that the sampling points they have chosen are all at or near to marine cage salmon fish farms.”
Linley-Adams pointed out that the chemicals were designed to kill crustacean sea lice on farmed salmon, and that they were released into the water and seabed around fish farms.
“Are we sure that these residues are having no effect on local populations of other crustaceans, such as prawns and lobsters, upon which many inshore fishermen rely for their livelihoods?” he asked.
The Scottish Salmon Producers’ Organisation, which represents the industry, argued that there was no problem. “We work within consent limits set by Sepa to ensure our unique marine environment is maintained and we are reassured that these reports confirm this is the case,” said Scott Landsburgh, the organisation’s chief executive.
On Friday the Scottish government released new figures showing that farmed salmon production increased by seven per cent between 2009 and 2010, from 144,000 to 154,164 tonnes. That’s the highest level in six years, officials said.
Farmed salmon is Scotland’s single largest food export, with most going to the US, France, Poland, Ireland and China. Last year the industry was worth £540 million, and was the third largest in the world after Norway and Chile.
‘Pesticides killed my business’
Donald Macleod knew he had a problem when he found dead prawns in his creels. “There’s something very wrong here,” he thought.
Since then, his 20-year-old fishing business has collapsed, and he’s sold his boat. Two months ago, he left his native Isle of Lewis to go and try and make a new life in Wales.
Macleod (43) used to fish prawns in Loch Shell on Lewis. But in 2009 he noticed that they were starting to die, and began asking questions.
Scientists from the Scottish Environment Protection Agency (Sepa) came to investigate, and detected traces of two fish farming pesticides in the loch sediments. At his suggestion, they also took away some dead prawns to analyse.
Unfortunately Sepa’s Stornoway office was unable to analyse them, and they were thrown away. In response to a request under freedom of information law in September, Sepa said that’s why it didn’t have any analysis results from the dead prawns.
“The worst thing is not knowing for sure, not being able to prove anything,” Macleod says. “But I’m convinced that the prawns were killed by the chemicals used by fish farmers to treat sea lice.”
There’s hardly any prawns to be found in Loch Shell any more unless you go some distance from the salmon cages, he claims. And prawns aren’t that different from the sea lice that the chemicals are designed to kill.
“It has become obvious that fish farmers can do almost anything they want and no-one has the ability to deal with the mess they can create,” Macleod says. “My income dropped by half because the prawns weren’t there, so I had to give up.”
Looking back, he feels sad and speaks with weary resignation. “What’s the point? What could I do about it?” he sighs. “What’s the point of anything these days?”
The lochs contaminated by pesticides
Loch Linnhe, Fort William: teflubenzuron and emamectin
Loch Ewe, Poolewe: diflubenzuron and emamectin
Loch Nevis, near Mallaig: diflubenzuron and emamectin
Loch Kanaird, near Ullapool: teflubenzuron, diflubenzuron and emamectin
Summer Isles, Achiltibuie: teflubenzuron, diflubenzuron and emamectin
Loch Fyne. Lochgilphead: emamectin
Portree Bay, Skye: teflubenzuron and emamectin
Loch Slapin, Skye: teflubenzuron and emamectin
Loch na Keal, Mull: teflubenzuron and emamectin