Photo Copyright by Michael Easton
The following is a small selection of the many articles written at the time of the release of Dr. Easton's paper on the contaminant levels in farmed salmon. This research subsequently had a profound effect on the marketing and production of farmed salmon.
Farmed salmon study raises cancer questions
by Frank Fuller
The Anchorage Press. July 26 - August 1, 2001 / Vol. 10, Ed. 30
When almost two million tons of salmon are caught and eaten in the world each year — over half from salmon farms — how can anyone generalize their condition from an analysis of 18 salmon?
These 18 salmon are the center of a controversy that began in England last winter and spread to Canada after two studies found that farm salmon had up to 10 times more polychlorinated biphenyls (PCBs) in their fat than wild salmon.
PCBs are chemical compounds that, although banned in the U.S. since 1979, do not break down easily and remain in the environment indefinitely. When eaten, they are generally stored in fatty tissue, can cause developmental abnormalities and are considered "probable human carcinogens."
Dr. Miriam Jacobs of the University of Surrey in England conducted the first look into farmed salmon in conjunction with the U.S. Environmental Protection Agency. Her study, published last year, analyzed 10 fish from Scottish fish farms and the wild. It found high levels of toxins, including PCBs, in all the fish, but she could not generalize a conclusion from the small number of fish sampled.
Dr. Michael Easton, president of International EcoGen, Inc. in British Columbia, did a second study using eight salmon, both wild and farmed. Easton found that farmed salmon contained up to 10 times more PCBs than wild salmon.
"The results of this study were so compelling that my funder was eager to get the material published," Easton said.
The study, commissioned by the David Suzuki Foundation — an environmental organization that has been highly critical of fish farming — will be published later this year in the journal Chemosphere.
The two studies were featured in a BBC documentary that was later shown on the CBC. The Canadian documentary led to a flurry of newspaper articles and letters to the editor in Europe and Canada. But the issue has been almost completely ignored in U.S. media.
"I think the primary problem is that these studies looked at very small samples, so the results should be characterized as preliminary," said Dr. Rebecca Goldburg, a senior scientist with Environmental Defense who studies food production issues. She did not dismiss the results as aberrations or as incorrect, however, and added that these results demonstrate the need for further, more detailed studies. "It is probably premature to draw sweeping conclusions," she said.
Dr. Easton admitted that the sample size was troublesome. "The only controversial issue might be the sample size," he said. "We used one of the world’s leading labs in determining the level of contaminants. So the analytical chemistry is above reproach. We actually used as many samples as the Canadian food inspection agency uses to determine whether samples of the fish are safe. So the sample size is no different from what the government itself uses."
He added that they are planning another study to look at this issue in more depth.
The president of the B.C. Salmon Farmers Association, however, has been leading the charge against these studies.
"The British documentary takes things up a notch when it asserts that consumers could be exposed to dangerous levels of toxins by eating farm salmon. The basis for this serious accusation is so thin as to be virtually non-existent, but is presented in a manner clearly designed to maximize public alarm," says Anne McMullin, a spokesperson for B.C. Salmon Farmers Association.
McMullin has been critical of the design of Easton’s study. In a letter to the editor of the Vancouver Sun, she wrote that the study has not been peer-reviewed or published and that Dr. Jacobs called claims of high levels of PCBs in farm fish "nonsense."
Those who stand by the studies report that salmon feed seems to be the main culprit behind the contaminated fish. "The European Union last November released a study in which [they] looked at dioxins and PCBs in feedstuff for animals — not just fish, all animals — and the feedstuff that was by far the most contaminated were fishmeal and fish oil, which are constituents of salmon feed," Dr. Goldburg said.
Salmon feed comes from fish high in oil, such as anchovies. Up to three pounds of such fish are needed for farm salmon to gain one pound. PCBs and other pollutants like pesticides and dioxins accumulate in fatty tissue and are passed on to animals that ingest that fat. A predator like salmon accumulates more PCBs in its fat than fish lower in the food chain.
"At least one rationale for believing that farmed salmon could have higher levels of toxins than wild salmon is that they are fed a diet very high in fish oil. The result is a fatty product and potentially one that could be somewhat higher in toxins than wild salmon, which still eat fish but maybe not with the same oil content as farmed salmon."
Adding to this controversy are studies that show farmed salmon to be up to four times fatter than wild salmon, which would enable them to store even more toxins. One, by Dr. Jacobs, will be published soon.
Different health agencies suggest various safety levels for toxins in food, so guidelines differ from country to country. The lowest levels are currently the World Health Organization’s guidelines.
"If we look at levels set recently, like the WHO levels, we discover that you couldn’t even eat one portion of the Scottish farmed salmon a week and not exceed the WHO levels," Dr. Easton said. "In Canada, you shouldn’t eat more than one portion a week of the farmed salmon." The PCBs found in these studies fall below FDA guidelines.
BC salmon farmers, however, insist that fish in general and salmon in particular remain nutritious, and that nutritionists continue to recommend two to three servings of fish a week in a healthy diet.
"Food experts around the world recognize salmon, farmed or wild, as a nutritious source of food protein, with a number of health benefits associated with high levels of omega-3 fatty acids. Regular consumption has been shown to reduce rates of heart disease, stroke, high blood pressure, depression, Alzheimer’s Disease, childhood asthma, among other conditions," she wrote.
Farmed salmon account for about 55 percent of the salmon consumed in the U.S. Most farmed salmon come from Canada and Chile, although European farms are an increasing source.
|Toxins, fat content higher in
farmed salmon, studies say
Yvonne Zacharias Vancouver Sun - July 21, 2001
That mouth-watering pink salmon you have been throwing on the barbecue on warm summer nights might not be as good for you as you thought.
Two researchers, one local and one in Britain, have been stirring up a storm of controversy with their conclusions that farmed salmon has more concentrated levels of toxins than its natural, wild cousin. Now the British researcher, Miriam Jacobs, a nutritionist at the University of Surrey in Guildford, England, has poured more oil on the fire with new claims that the fat content in farmed salmon is as high as 20 per cent.
Given that British Columbia produces four times as much farmed salmon as the wild type, chances are it's the former you are grilling, particularly if it has the telltale marbled look. With no requirements for labeling, you might never know.
Figures on fat content offered by Canadian authorities vary, but the B.C. Salmon Farmers Association says a three-ounce serving of its members' product contains 11 grams of fat, compared with seven grams in the wild variety. A British authority quoted in the Sunday Times of London placed the fat content of most farmed fish in Britain at around 14 per cent, which is roughly the same as the Canadian farmed salmon which would have a fat content by weight of about 13 per cent.
By comparison, a three-ounce serving of chicken contains eight grams and pork loin 10 grams.
Anne McMullin, executive-director of the salmon farmers' association, pointed out that salmon, including the farmed variety, contains a heart-healthy kind of fat known as Omega-3, but here again, the water gets murky.
McMullin says a three-ounce serving of farmed salmon contains 1.8 grams of Omega-3 fatty acids while an equal portion of the wild variety contains only 1.5 grams. But Christina Burridge, managing director of the B.C. Salmon Marketing Council, says there is some debate over how much of the fat content in farmed salmon is of the Omega-3 variety.
"There is no definitive research on that," she said. "In fact, there is a fair amount of contradictory research."
The fat-content controversy comes as no surprise to Peter Tyedmers. The ecological economist, who has just graduated with his PhD from the University of British Columbia and who now works as a consulting researcher for the university's fish centre, has been studying what is fed to farmed fish.
As a way of increasing profits, he says, the industry has been steadily increasing the amount of fish oil in pellets fed to farmed fish, which are plumped up in cages sunk into the sea. The amount of fishmeal or protein has been steadily decreasing. When the industry started up, the pellets were only between five and nine per cent fish oil; now, they are between 20 and 25 per cent, he said.
Because the local industrial sea fishing industry cannot meet the demand for these pellets, Tyedmers said, much of the supply is coming from the South Pacific, China, Peru and the U.S.
As the fat content increases, so do toxins like polychlorinated byphenyls, pesticides and other chemicals that have been blamed for causing everything from cancer to decreased fertility in humans.
As Tyedmers explained, fat is friendly ground for them.
As another way of reducing costs, the salmon farmers' association admits its producers feed fish an additive called astaxanthin, giving it the tantalizing pink look native to its wild cousin, which gets that healthy glow naturally by eating algae and plankton.
The local stakes in the debate are huge. The industry has grown by leaps and bounds in B.C. since it started up in the mid-1980s and is poised for a major expansion this fall. Last year, farmed salmon was B.C.'s largest agricultural export and 3,400 people were employed in the industry.
This isn't the first time Jacobs has waded into these choppy waters. Nor is she alone. B.C. geneticist Michael Easton, who operates a company in North Vancouver that specializes in studying the genetic impact of contaminants, has also questioned the nutritional safety of farmed salmon in a two-year study partly funded by the ultra-green David Suzuki Foundation. Independently, but almost simultaneously, Jacobs and Easton managed to come up with a comparative snapshot of farmed and wild salmon that is troubling for health-conscious consumers and for the fish-farming industry.
In her initial study, Jacobs looked at 10 Scottish farmed salmon and two wild fish. She found harmful dioxin levels significantly higher in the former variety. So high, in fact, that eating just one 3.5-ounce portion would exceed the weekly maximum acceptable dose of dioxins in Britain.
In his soon-to-be-published study, Easton studied four farmed and four wild salmon. He found the levels of polychlorinated byphenals, pesticides like DDT and other toxic substances in farmed salmon were 10 times higher than the levels in the wild salmon.
The levels are still well within Canadian safety standards, he said in an interview, but come close to exceeding the World Health Organization's recommendation for tolerable daily intake. He noted that the WHO standards were upgraded in 1998 and argues that Health Canada's guidelines are too low.
"Typically, we look at these contaminants at very low levels for their impact because the genetic level of damage occurs are much lower levels than current regulations consider."
The implications of genetic damage are quite significant, he said, adding they include cancer and all sorts of other diseases that are becoming more prevalent. He said he would not eat farmed salmon.
"I consume quite a bit of salmon and it would be foolish to eat salmon that is so close to the WHO tolerable daily intake levels."
Everyone agrees that the small samples don't provide definitive data, but they are hardly comforting and raise enough concern to warrant a closer look.
The B.C. Salmon Marketing Council, with its "go wild" motto, has been promoting wild salmon, but the research is so spotty, Burridge said, it is impossible to claim that wild salmon is nutritionally superior.
"I'm absolutely convinced that wild salmon tastes better than any farmed salmon," she said. "I encourage people to eat wild salmon."
Dietitians in B.C. still recommend two to three servings of fish a week, with no distinction made between wild and farmed varieties, and Canadian Food Inspection Agency spokesman Susan Schenkeveld said tests of both wild and farmed salmon have not turned up evidence of excessive levels of contaminants. The agency hasn't compared levels in the two types.
McMullin was quick to pour water on Jacobs' earlier findings, noting that the researcher herself was upset with the way the British Broadcasting Corporation used her earlier research in a documentary aired last January that caused waves on both sides of the ocean and caused shares in the fish-farming industry in Britain to plummet.
At one point, the BBC, mixing up her findings with those of Easton, falsely attributed to her a statement that farmed salmon contained 10 times more toxic polychlorinated byphenals than wild salmon. The mistake was quickly corrected. In a news release issued by the university, Jacobs maintained, however, that her main point regarding high levels of persistent organic pollutants in farmed salmon was confirmed in both her and Easton's studies.
The nutrition issue joins a litany of environmental concerns over the growing presence of farm-fish cages in the ocean. There are concerns that waste from the farmed fish are creating pools of pollution around the cages and that escaped farmed Atlantic salmon, which have already been spotted by B.C. fishermen, will displace weakened stocks of the wild variety and give rise to new hybrid Frankenfish. Reputable scientists call its accidental release an act of "biological pollution."
They warn that farmed Atlantics will introduce diseases into West Coast waters where native species have no natural immunity and that drugs used to keep farm fish healthy might spawn antibiotic-resistant supergerms in the ocean. McMullin's association couldn't pinpoint the level of antibiotics fed to farmed fish, although it claims the amount is small and that antibiotics are administered only when the health of the fish is threatened.
B.C. commercial fishermen are complaining that the glut of farmed salmon on the market is driving prices so low they no longer cover their costs.
Initially regarded as a huge step down the path of progress at sea, fish farming is a billion-dollar business stretching from Norway to Chile. Over 20 years, world production of farmed salmon has grown from 5,500 tons a year to more than 660,000 tons, according to the World Wildlife Federation. It more than doubled between 1995 and 2000.
In B.C., McMullin said new regulations governing the industry should be in place by September.
"Then we will look at the second stage, which will be growth."
|WEDNESDAY JANUARY 03 2001|
|Farmed salmon may be 'polluted'|
Farmed salmon can contain up to ten times the amounts of pollutants - including pesticides and chemicals - as are normally found in wild salmon, according to research.
Growing concern about the findings has prompted the World Health Organisation to cut its guidelines on the recommended intake of salmon to a tenth of the previous figure.
Details of the study, which will be disclosed in a BBC2 programme on Sunday evening, show that the farmed fish industry is the fastest growing food sector in the world, and that salmon farming is a production success story.
But the programme claims that the industry has had a catastrophic impact on populations of the wild salmon near the farms.
Apart from spreading parasites and poisoning local marine life, farmed salmon were escaping into the wild and upsetting the genetic make-up of the wild salmon.
Although farmed salmon contains health-enhancing fatty acids, the programme uncovers evidence that farmed salmon may themselves be contaminated with toxins which have implications for human health.
Of the 95 million tonnes of fish trawled worldwide, about one third is not for human consumption but used to make fish oil or meal for livestock.
Dr Michael Easton, who recently carried out a pilot study for Canada's David Suzuki Foundation, told the programme: “The results were very very clear - farmed fish appeared to have a much higher level of contamination and in wild fish the difference was extremely noticeable."
He said the problem lay in the food fed to captive salmon, which was made from species trawled from the world's oceans and concentrated into pellets. The minute traces of toxins are multiplied into a more significant dose.