Killer lice

A parasite the size of a thumbtack is flourishing in B.C.'s fish farms - and wiping out the wild salmon, writes Taras Grescoe
Wild salmon are virtually extinct in the Atlantic Ocean, yet tens of millions of Atlantic salmon are being raised in farms in the Pacific; the U.S.-based Safeway supermarket chain has announced that it is curtailing purchases of disease-ridden farmed salmon from Chile; and returns of wild salmon on the British Columbia coast seem to be declining from year to year.

Choosing farmed salmon, some people will tell you, means consuming some of the most toxic chemicals known to humanity. Opting for wild-caught salmon, others insist, could make you complicit in driving already fragile salmon stocks to local extinction. No wonder so many people end up settling for chopped cucumber in their maki rolls at the sushi bar.

Yet there really is no need for confusion. Where you stand on the wild-or-farmed-salmon issue should come down to what you think about a thumbtack-sized crustacean that survives by eating the scales and skin off the same fish that we love to eat - an ugly, creeping, little beastie known as the sea louse.

I was first shown sea lice on salmon smolts by Alexandra Morton, an American-born marine biologist who has lived in a floathouse in Echo Bay, in the Broughton Archipelago, for more than 20 years. The Broughton, a jumbled jigsaw puzzle of islands scattered off B.C.'s mid-coast, is home to sea otters, great blue herons and, until recently, a resident population of killer whales. It is considered one of the richest pockets of biodiversity on the coast - or at least it was until the salmon farms came along.

Aboard her boat one afternoon, Ms. Morton told me how she had welcomed the first net cages when they were towed into local bays in the late 1980s: She hoped that they would provide employment for local people. But then the killer whales were driven away by the acoustic devices the farms used to discourage them and other predators, fishermen started pulling up prawn traps and clams dripping with rotting pellets and salmon feces, and the wild salmon began to disappear.

In the late 1990s, a Scottish tourist at a fishing lodge near Ms. Morton's floathouse asked, "Do you have the scourge of the sea lice yet?" The visitor explained that after the salmon-farming industry came to Scotland, sea lice started appearing in great quantities on wild fish; he had seen the same parasites on the salmon he had just caught in the Broughton.

Alarmed, Ms. Morton took out a dip net and pulled up dozens of wild juvenile pink salmon. They were bleeding from the eyeballs and the base of the fins. Most of them were covered with brown flecks - juvenile sea lice. As they grow, changing their body shape every few days, these parasitic copepods strip mucus, scales and skin from the growing fish. While a full-grown salmon has an armour coating of scales and can survive an infestation, the parasites exhaust the young fish and quickly kill them off.

Using hand seine nets to sample local waters, Ms. Morton established that the salmon farmers were raising millions of adult farmed Atlantic salmon along the migration routes of wild Pacific salmon - in exactly those inlets and estuaries where juvenile wild Pacific fattened up before going to sea. Suddenly, the decline of wild salmon populations did not seem like such a mystery: The 27 farms in the Broughton, had, by crowding normally nomadic fish into tightly packed nets, become ranches for sea lice, concentrating and fatally passing on parasites to wild salmon when they were at their most vulnerable.

In 2002, government scientists predicted that 3.6 million pink salmon would return to the Broughton. Fewer than 150,000 did - a 97-per cent-population crash.

Though the salmon farming industry has done its best to muddy the waters, Ms. Morton has science, as well as some of the leading fisheries scientists in the world, on her side. Analyzing data from Ireland, Scotland and Atlantic Canada, the late Ransom Myers of Dalhousie University showed that disease and parasites spread by farmed salmon reduced the survival of local populations of wild salmon and sea trout by more than 50 per cent per generation. In December, 2007, Ms. Morton and colleagues from the University of Alberta and Dalhousie published a paper in Science, one of the world's most prestigious peer-reviewed science journals, projecting the complete collapse of pink salmon in the Broughton by 2011 if the sea lice continue to infest fish.

The evidence is on their side: Everywhere salmon farms have appeared, from Norway to Chile, they have spread disease and parasites to local fish. This year, Ms. Morton told me, sea lice have for the first time shown up on juvenile herring and sockeye in the Strait of Georgia; she found large numbers of them near a fish farm in Clayoquot Sound (a UNESCO Biosphere Reserve where the multinational Mainstream, which is 45-per-cent owned by the Norwegian government, has been allowed to operate 14 salmon farms).

This spring, thousands of newborn pink salmon are leaving the Broughton Archipelago's Ahta River and schooling near the 600,000 adult Atlantic salmon awaiting harvest at the Glacier Falls farm. Employees have already treated fish in the farm with a pesticide called Slice, a potent neurotoxin that kills not only sea lice, but also affects lobsters and other sea creatures we eat. (Though Slice has never been officially approved in Canada, "emergency" permits are routinely granted to salmon farmers by veterinarians, and Health Canada now allows trace amounts of Slice in the flesh of farmed salmon in our supermarkets.) But even this heavy-duty poison has not killed off all the sea lice this year. Samples taken by Ms. Morton show that 17 per cent of the juvenile fish next to the Glacier Falls site are already infested with the parasites.

In March, she announced plans to "medevac" the fish to safety. Using a technique that is standard in hatcheries, she would net the juveniles, put them in a tank full of ocean water and ferry them past the Glacier Falls farm and back to their migration route. On the day of the proposed operation, a seaplane touched down beside her boat, and she was handed a letter, informing her that the federal Department of Fisheries and Oceans had refused to give her permission to transport the fry.

"The department rejected the idea," Ted Perry of the DFO's Pacific Biology Station in Nanaimo told CBC Radio, "because we think it's the best thing for the fish. There's a lot of handling that goes on with the proposed moving. ... It's a very stressful process for young fish."

For Ms. Morton, the DFO's contention that it rejected her plea purely in the interests of the fish is just so much spin. She points out that the department currently has a team in the Broughton netting and killing thousands of juvenile salmon for scientific purposes.

"The government is still trying to make this sound like it's a really complicated issue," she says. "It's not. It's simple: Industrial salmon farms in British Columbia are spreading sea lice to wild salmon. Where political will is behind the wild fish and the salmon farms have been banned, the fish are doing just fine."

She points out that Alaska, whose economy depends on the wild catch and where salmon farms are strictly prohibited, had two of its biggest harvests in history for pink and sockeye salmon last year.

The salmon farmers have accused Ms. Morton of engineering a publicity stunt, using photogenic baby fish to draw attention to their industry.

She and her colleagues counter that their concern is genuine: These may be among the last generations of pink salmon in the Broughton Archipelago. (Ms. Morton's funding comes in dribs and drabs from B.C. fishermen sympathetic to her cause. She is trying to raise money to challenge the government's decision at http://www.adopt-a-fry.org.)

Meanwhile, what is a consumer who is inclined to eat ethically to do? Oddly, the best way to save the wild salmon of the Pacific may be to eat them (in moderation, of course, and paying close attention to which species and stocks are abundant; pink salmon runs from other parts of B.C. are healthy, and Nass River sockeye and most Alaskan salmon stocks are in good shape).

Eating farmed salmon, in contrast, encourages an industry that is insidiously undermining wild stocks around the world. The industry could clean up its act by switching to land-based, closed-containment systems that don't spread parasites and pollutants to the wild. Until then, however, supporting well-managed sport and commercial fisheries, and subsidizing habitat restoration, is the only way to ensure that wild salmon will survive into the future. We need to look at salmon the way we used to: not as the cheap protein in a million in-flight meals, but an occasional luxury - one that is well worth paying more for.

When Robert Burns wrote To a Louse in 1785, the rivers of Scotland - and those of much of Europe - supported healthy populations of wild salmon. Generations of overfishing and habitat destruction in the fjords and firths effectively dug a mass grave for the wild fish; the disease, pollution and parasites that arrived with industrial salmon farms spread the final layer of quicklime on their corpses. In the Atlantic, wild salmon are now considered commercially extinct.

The salmon of the Pacific still stand a chance. Yet when Irish and Scottish scientists and fisheries managers came to B.C. last year to testify before the province's Special Committee on Sustainable Aquaculture about how sea lice had killed off their native salmon and sea trout populations, they were shocked. Why, they wondered, would Canadians risk endangering one of the planet's last great salmon populations to profit a few Norwegian companies?

I have been wondering the same thing myself. The great mystery is what we as Canadians stand to gain from salmon farming. Of the 149 sites in B.C., 130 are fully owned by Norwegian companies, while only 11 are wholly Canadian-owned. The profits go to bank accounts in Oslo, licensing fees are laughably low and companies are allowed to continue operating farms even after their leases have expired. Local employment is minimal and rarely long-term - as I witnessed on my visit to several farms, the staff is mostly college-aged - and as the industry becomes increasingly automated, the ratio of jobs to kilograms of fillet produced constantly decreases.

The province's marine sports fishery, which one day may disappear because of sea lice, employs 4,200 and brings $158-million of revenue to the province. Salmon farming provides only 1,800 full-time jobs and, according to B.C.'s Ministry of Environment, contributes just $61-million to the gross domestic product.

As Canadians, citizens of a country that once had a worldwide reputation for its forward-thinking environmental policies, we should be mortified by our elected officials' shortsightedness. (This month, the B.C. government announced a moratorium on new permits north of Klemtu - a village 275 kilometres south of the border with Alaska. Meanwhile, they quietly approved two new farm permits on the south coast.)

Like the most parochial banana republic of old, we've leased out our natural riches to a handful of distant head offices. They reap the profits, and we pay the environmental price - in the form of ever lousier and increasingly scarcer wild salmon.