Scientists are divided over virus threat to Northwest salmon
Atlantic salmon in a net-pen.
By Kirk Johnson
Copyright 2013 New York Times News Service
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PORT ANGELES — In May 2012, a deadly fish virus known to affect wild salmon hit an American Gold Seafoods fish farm off the southern tip of Bainbridge Island.
The entire stock of farmed Atlantic salmon — more than a million pounds — was removed and killed.
The disease, an influenza-like virus called infectious hematopoietic necrosis, or IHN — triggered concerns that it might spread to American Gold's other saltwater fish farms off Port Angeles and near Cypress Island and Hope Island in Puget Sound.
But they were not affected.
IHN, which does not affect humans, occurs in wild sockeye salmon and can be carried by other fish, such as herring, that sometimes pass through fish net pens, affecting the farmed fish.
It was the first time the virus was detected in Atlantic salmon in Washington state.
It first appeared in two British Columbia fish farms earlier in 2012, forcing the destruction of almost 600,000 fish.
American Gold is affiliated with Icicle Seafoods of Seattle.
Its Port Angeles pens are in the harbor on the south side of Ediz Hook, near the Coast Guard station there.
In July 2006, a deadly “brown tide” swept through local waters, killing about 100,000 Atlantic salmon in the Port Angeles fish farm before dispersing.
The loss in Port Angeles and at the Cypress Island fish farm off Anacortes was estimated in the millions of dollars by American Gold Seafoods.
The brown tide was caused by a single-celled, brown-colored organism called Heterosigma.
Natural and not caused by pollution, Heterosigma blooms a few times each decade, usually in summer months when water conditions are just right.
After the Bainbridge Island salmon were killed and removed in 2012, the net pens were disinfected, and the fish farm was later put back in operation.
The IHN outbreak prompted Washington-based Wild Fish Conservancy to call for tougher testing rules and limits on net-pen salmon aquaculture.
There are nine saltwater fish farms in the state. The pens produce about 10 million to 12 millions pounds of salmon each year worth about $20 million.
Fish farms in Washington are regulated by the state Department of Ecology.
The Port Angeles fish pens have been in the harbor since the early 1980s and have gone through several ownership changes.
As many as three employees tend to the Port Angeles pens, and the salmon are processed in the Seattle area.
Proposed legislation that would allow coastal counties to forbid marine aquaculture net-pen facilities died in committee during this year's legislative session in Olympia.
The legislation was introduced by state Rep. Kevin Van De Wege, D-Sequim, and state Sen. Jim Hargrove, D-Hoquim, two of the three legislators who represent the the 24th District, which comprises Jefferson and Clallam counties and part of Grays Harbor County.
Phil Johnson, one of the three Jefferson County commissioners who has led the effort to ban the industry in that county because of fears of harm to native fish, said he was “extremely disappointed” that the legislation had died.
The commissioners are now trying to restrict the possibility of fish farms in Jefferson County waters by developing a tough conditional-use permit process for net-pen aquaculture — it would be used in the event that any such businesses ever apply to be sited within the county.
Farming Atlantic salmon began in Norway in the 1970s.
The fish are now raised across the globe in large floating open net-cage pens, usually located in sheltered bays.
Atlantic salmon are used because, on average, they are less aggressive and grow faster and more efficiently than wild Pacific salmon.
In addition to disease concerns, critics say farmed salmon often escape their nets and disrupt the spawning of wild salmon species in local rivers or compete for food.
American Gold and Washington state regulators say fish farming is safe and that disease and escapes are rare problems.
Most say there is no evidence.
But for years, a biologist in Canada named Alexandra Morton — regarded by some as a visionary Cassandra, by others as a misguided prophet of doom — has said definitively and unquestionably that they are wrong.
Infectious salmon anemia
Wild Pacific salmon, she has said, are testing positive for a European strain of the virus that causes the disease, infectious salmon anemia, or ISA
The virus, which has struck farmed salmon populations in Chile, among other places, is not harmful to humans who eat the fish, but could potentially pose grave threats in a part of the world where salmon plays a huge role in local economies and ecosystems.
If the virus, which is in the influenza family, mutates into a virulent Pacific strain in the crowded fish farms in British Columbia, where wild and farmed salmon are sometimes in proximity, fish populations on both sides of the farm/wild divide, Morton believes, could be devastated.
“It's an uncomfortable truth,” she said.
But scientists and government testing groups in Canada and the United States have said repeatedly over several years that Morton's findings were not sufficient to sound an alarm, and that the risks to wild salmon, even in the event of a fish-farm outbreak, are unclear.
After rounds of government hearings and millions of dollars spent on research, the two sides are in an increasingly bitter standoff.
“We're trying to re-create the situation that she's saying is out there, and to date we cannot re-create the results,” said Dr. Penny Greenwood, national manager of the domestic disease control program at Canadian Food Inspection Agency.
Now, Morton has new test results that she said are positive for the infectious salmon anemia virus — though not necessarily the disease — in farmed salmon she bought at a fish market in Vancouver late last year.
At the same time, the biggest effort ever on the American side of the border to find the virus is shifting into high gear, with fish samples arriving in labs in Idaho, Alaska and here in Washington State.
“I think we're probably pretty close to having a definitive answer,” said Martin Krkosek, an assistant professor of ecology and evolutionary biology at the University of Toronto.
Much at risk
The stakes are enormous, and not least for reputations.
Salmon, in all their varied and usually pink-hued glory, have been an ecological anchor from Alaska to Oregon, intertwined with the region's culture and economy since long before the arrival of Lewis and Clark.
The search for the virus raises questions that have swirled through commercial fishing and oceanography:
Has the growth of open-ocean fish farming over the last three decades and the vast netted pens of Atlantic salmon from Chile to Maine and Norway to Canada created a reliable source of sustainable, inexpensive protein?
Or, as critics contend, are the farms unsustainable because they pollute the seabed and because the close confinement of the fish raises the risk of disease?
Salmon farmers say that the broader controversy over aquatic farming has informed the narrower discussion of the salmon disease, and that Morton in particular has been out to get them, whether a virus is involved or not.
Adding further fuel — or at least, smoke — to the fire is a new documentary that accuses the Canadian government of deliberately covering up evidence that would support Morton's conclusions.
A Web site has since emerged that tries to debunk to the documentary.
“She says one thing, everybody else says something different, and therefore, in her view they're all in collusion, and not doing a good job,” Ian Roberts, a spokesman for Marine Harvest Canada, the biggest salmon farming operation in British Columbia, said of Morton.
He said his industry had sent upward of 8,000 samples for testing in recent years, without a single confirmed finding of the ISA.
And he said the survival rate at his company's salmon farms was better than 90 percent.
New outbreak recently
There is no doubt that the disease can wreak havoc.
First described in Norway in the mid-1980s, it has flared on fish farms from Maine and the eastern coast of Canada to Scotland and Chile, which reported a new outbreak last month.
The virus is also capable of mutating rapidly, which scientists on all sides of the issue say increases the need to keep an eye on it.
Its victims can be seen gasping at the surface, lethargic and often swollen with fluids; mortality can reach 90 percent.
The global seafood industry, meanwhile, has become harder than ever for researchers to monitor, with well-established problems of labeling and provenance.
A recent study, for example, of fish purchased in markets and restaurants around the nation by a nonprofit ocean protection group, Oceana, found that about a third of the samples tested were mislabeled.
Dr. Greenwood of the Canadian food agency said that research to determine where one of Morton's market-purchased samples came from produced conflicting accounts from people in the supply chain.
Without a clear chain of custody, she said, there was no point testing the fish at all.
She said there had been no attempt to cover up anything.
“We couldn't even verify that that fish was in fact Canadian in origin,” she said.
Wild fish coming into proximity with farmed fish is partly what raised disease concerns in British Columbia in the first place.
Some fish pens, notably near the Fraser River, straddle the very corridor through which millions of sockeye salmon pass each year, both during their juvenile outmigration to the ocean and upon their return as adults to breed.
Those anxieties skyrocketed in 2009, when the salmon run on the Fraser suddenly collapsed, leading to a government inquiry in which infectious salmon anemia was discussed but never definitively implicated as a factor.
(The Fraser's sockeye salmon bounced back in 2010 with one of the biggest runs ever recorded, and have hovered around their long-term averages since then.)
James Winton, chief of the Fish Health Section at the U.S. Geological Survey's Western Fisheries Research Center in Seattle, one of the labs involved in the new wave of tests, said that assessing disease risks to wild salmon went far beyond how close they get to their farmed cousins.
Climate change, habitat loss, contaminants, variability of food supplies and ocean acidification, among other factors, may also play roles in affecting the susceptibility of wild salmon to diseases, he said.
Wild salmon remains a popular choice among diners, in part for its omega-3 fatty acids, which studies have shown are important for heart and brain health.
The state Department of Health in Olympia sums up its advice in three succinct words and a bit of pro-wild caveat:
“Keep eating salmon!” the agency says in its Web site.
“Wild salmon is a great choice and farmed salmon is a good alternative.”
Last modified: May 04. 2013 6:47PM