Like Monty Python’s Flying Circus, the Scottish salmon farming industry always looks on the bright side of life. Being condemned by a devastating US study for producing salmon is so contaminated with toxic chemicals that it is dangerous to eat isn’t something that gets Scottish Quality Salmon (SQS) down. On the contrary, it seems to buoy it up.
Confronted for the first time last week with unassailable evidence that farmed salmon were far more contaminated than wild salmon, and that Scottish farmed salmon were the most contaminated of all, the body that represents most salmon farmers put on more than a brave face.
“Study confirms safety of Scottish salmon,” was the unashamed headline of its statement in response to journalists. Never mind the study’s conclusion that eating farmed salmon could detract from the health benefits of eating fish, or its suggestion that people should eat no more than three helpings of Scottish farmed salmon a year if they want to avoid an unacceptable risk of cancer.
Instead SQS zeroed in on one sentence from the study which said that the levels of individual contaminants in salmon were within the safety limits laid down by the US Food and Drug Administration. Therefore, said SQS’s technical consultant, Dr John Webster, “consumers should be reassured by this research”.
Within hours of the US research being published on Thursday, SQS was being strongly backed by the UK’s Food Standards Agency (FSA). The watchdog’s chairman, Sir John Krebs, insisted contamination of salmon was within World Health Organisation (WHO) safety limits, and reiterated the official advice to eat at least one portion of oily fish, such as salmon, a week.
Not surprisingly this exchange has left consumers confused as to whether farmed salmon is safe to eat. It has also highlighted concerns about the independence and credibility of the FSA – and the overwhelming need for the salmon farming industry to adapt if it is to survive.
Dr Richard Dixon, head of policy at the environmental group WWF Scotland, pointed out that the FSA had been set up to end the cosy relationship between government and the food industry. “But it now seems to be falling into the same trap,” he alleged. “The FSA has attacked organic food, sung the praises of genetically modified food and is now urging people to ignore scientific advice suggesting that farmed salmon may be unsafe. It looks more like a defender of big business than a champion of public health."
The first problem with the FSA and SQS’s insistence that pollutants in farmed salmon are within safety limits is that they may be wrong, as the Sunday Herald reveals today. Scientists from the government’s Central Science Laboratory in York calculate that most people eating a single portion of salmon a week would exceed the WHO safety limit of four picograms per kilogram of body weight a day (a picogram is one million millionth of a gram).
This has provoked angry criticisms of the FSA, and new calls for it to revise its advice. “The FSA should urgently set contaminant limits which protect human health, not industry profits,” said Dan Barlow, head of research at Friends of the Earth Scotland. “The FSA must demonstrate that it is willing to champion human health and informed consumer choice, rather than defending food industry practices.”
The regulator and the industry also brushed aside the new US study as irrelevant and flawed. But it is by far the biggest study ever done, was published in one of the world’s top academic journals, Science, and was heavily refereed before publication by independent experts.
Leading environmental scientists from universities in Indiana, Michigan and New York analysed 700 farmed and wild salmon from around the world for contamination by a range of industrial pollutants and agricultural pesticides, most of which are now banned. They found that average levels of PCBs, dioxins, dieldrin, toxaphene and other chemicals were around 10 times higher in farmed than in wild salmon.
The contamination of salmon farmed in Scotland and the Faroes was twice that of salmon farmed in Canada, four times that farmed in Chile, and over 30 times higher than that of wild Alaskan salmon. Because the scientists regarded the safety limits applied by the US Food and Drug Administration as inadequate, they used much stricter cancer risk estimates from the US Environment Protection Agency.
These suggested that people who want to keep their added risk of catching cancer to below one in 100,000 should eat no more than 55 grams of Scottish farmed salmon a month. That amounts to about a quarter of a serving, and implies that Scottish salmon should be eaten no more than three times a year. And, the scientists stressed, the research doesn’t take account of the damage that the toxins could do to immune and reproductive systems.
They acknowledged there were health benefits from eating fish like salmon, that contain high proportions of omega 3 fatty acids, known to reduce heart-attack risk. But they concluded: “Consumption of farmed Atlantic salmon may pose health risks that detract from the beneficial effects of fish consumption.”
“I and my family do not eat farmed salmon,” revealed Jeffrey Foran, a University of Michigan toxicologist and one of the authors of the US study. “My hope is that public health agencies will look at our study and issue advice encouraging people to eat less contaminated fish.”
He stressed that the solution was not to shut down the salmon farming industry, but for it to reform and cut contamination. “I hope the industry doesn’t shoot the messenger,” he commented.
Amongst the worst polluted marine areas are the North Sea and the North Atlantic, where the pollutants are eaten by fish which are captured and made into fish oils. These oils make up 30% or more of the manufactured food pellets fed to salmon reared in cages, causing them to accumulate high levels of the toxins in their fatty tissue.
Despite SQS’s sustained and forthright attack on the US research, it does recognise that the presence of PCBs and dioxins in farmed salmon is undesirable. “The long-term aim is to remove these contaminants,” said SQS chief executive Brian Simpson . Salmon-feed suppliers have been increasing the proportion of fish harvested from less polluted regions like the South Atlantic, though they couldn’t turn their back on North Atlantic and North Sea fish, he explained. While the industry has been introducing carbon filtration technology aimed at reducing contaminants in fish oils.
Simpson also pointed out that investigations were under way into using vegetable oils like oil-seed rape, which would be much less contaminated. But these oils are not rich in omega 3 fatty acids, and they can also, in the words of one observer, make salmon “smell like putty”.
“This is something we are juggling with,” said Simpson. The levels of contamination in farmed salmon were going down, and would continue to go down, though he accepted it would be impossible to reduce them to zero. He also agreed that all the publicity from the US study might damage sales.
“You would be hard-pushed to say that this is not harmful.”
The salmon sold by farmers in Scotland are valued at around £700 million a year and are worth more to the economy than the Highland beef and lamb industries combined. The industry employs 6000 people, mostly in the Highlands and Islands.
But in the wake of the US study it is facing one of the most serious crises in its short 30-year history. If it succeeds in cutting contamination levels, it could flourish. But if it ignores what the US scientists are saying, it could founder.
“If they choose to misread a serious scientific study, then they only have themselves to blame,” said Paul Johnston, principle scientist at the Greenpeace research laboratory at Exeter University. “It is a clear case of garbage in, garbage out. It they feed salmon garbage, they will be contaminated.”
Toxic contamination is not the only problem facing the industry. Environmentalists have long worried about the sustainability of a process that harvests four tonnes of fish for food to produce one tonne of salmon. There have also been complaints about the pollution from salmon cages, with some blaming them for wiping out wild salmon by spreading sea lice.
But nobody is seriously arguing that the industry should be closed down, just that it is in dire need of an overhaul. And that requires something more radical than just looking on the bright side of life.