Salmon Roulette: Are we risking our Pacific Salmon for Atlantic Salmon Aquaculture?

By John Volpe

From: The Ring ( The University of Victoria's Community Newspaper)

OCTOBER 1, 1999 page 5

(http://web.uvic.ca/ucom/Ring/99oct01/viewpoint.html)

Not since the days of Juan de Fuca and Cook has the thought of invasion weighed so heavily on the collective conscience of people on our coast.

These current invasions are not ones of foreign cultures -- but of foreign plants and animals. There is almost daily media coverage of the latest species to land upon B.C. shores. If it's not mussel-devouring green crabs then it's the Asian longhorn beetle, or the honey bee-destroying varroa mite, or bullfrogs with a taste for ducklings. Movement of species beyond their natural borders has invariably resulted in negative consequences for native species in the target region. This is why the United Nations has declared the introduction of exotic species as the second greatest threat to global biodiversity after habitat destruction. The latest invasion story to grab front page ink in B.C. is that of Atlantic salmon. More than 32,700 ready-for-market adults escaped two weeks ago at a Vancouver Island fish farm. The depressed state of our native salmon populations and the commercial and sports fisheries that depend on them make this potential invasion particularly worrisome. In the public's eye this is one invasion story that should have and could have been avoided. Are we risking our native salmon heritage for Atlantic salmon aquaculture?

Answers are not so straightforward. Salmon aquaculture is big money in B.C., and with it comes persuasive lobbying power. On the surface it's an easy sell: stitch some nets together, fill your pens with young salmon, feed them to maturity, and harvest for a handsome profit. You provide employment for beleaguered coastal communities and reduce harvest pressure on over-exploited Pacific salmon stocks. The program sells itself.

However, the reality is not quite so cheery. To satisfy the need for fish meal, vast quantities of fish are being removed from southern oceans.

Three kilograms of wild fish (plus an unknown quantity of bycatch) are required to produce one kilogram of salmon. This is not a sustainable enterprise.

Most fish farms are owned by offshore multinational companies and are high-tech facilities geared towards minimizing on-site personnel. As technologies mature, the industry will no longer be a significant coastal employer. Further, to be profitable, fish farms are run feedlot-style and like similar land-based operations, rely on drugs to maintain a healthy population.

The inadvertent breeding of "superbugs" or drug-resistant bacteria is promoted in this way, and the potentially devastating long-term ramifications of such

practices are only now becoming fully appreciated. And the notion that salmon farming reduces harvest pressures on wild salmon is a fallacy. For years, there's been an oversupply of salmon on the world market due to aquaculture overproduction, and salmon prices have remained correspondingly low. As prices dropped, commercial fishermen have had to increase their harvests just to maintain their earning power.

The most immediate concern is the large number of fish being released from fish farms. In B.C., more than 80 per cent of production is of Atlantic salmon, which, as its name plainly states, is not native to the Pacific. An estimated 60,000 to 100,000 Atlantic salmon escape into B.C. coastal waters annually (in reality no one really knows how many escape). When escapes occur, the big question on everyone's mind is: What effect are the escapees going to have on our native stocks?

Unfortunately for the uninformed, there is a variety of answers being offered. Most are products of media-savvy organizations that have only thinly veiled their particular slant on the issue. Last summer, I confirmed the first natural spawning of escaped Atlantic salmon in a B.C. stream.

The response from the B.C. Fish Farmers Association was that this discovery meant nothing. A few fish here and there does not make an invasion, it claimed. Meanwhile, the federal Department of Fisheries and Oceans ignored its primary mandate of conservation and parroted the words of industry without a moment's hesitation, and provincial authorities cautiously sat on the fence. The most recent escape at Port McNeill has again provided fodder for the spin machines, resulting in a dog's breakfast of presentations to the public. What does it really mean though?

The short answer is we don't know. Industry continues to hold up the 1997 provincial salmon aquaculture review as evidence of the benign nature of fish farms. The outcome of the review was a set of volumes larger than the Toronto phone book and a vague "cautious yellow light" for industry expansion. Unfortunately, the review was just that -- a review. Data from the North Atlantic and local historical anecdotes were seamlessly applied to present-day B.C. without anyone questioning the soundness of the underlying logic. To think that the current escapees will share the same fate as those a continent away is hopelessly simplistic.For similar reasons, because Atlantic salmon failed to colonize 70 years ago bears no relevance to today. Lake Ontario was exposed to zebra mussels for a century before they "stuck" in the mid-1980s. Ten years of consistent releases were required to establish European starlings (in New York City's Central Park) in the early days of this century. The natural world is a dynamic place and in a constant state of flux. If a species is introduced often enough, chances are that conditions will eventually swing in its favour. What may seem like subtle changes to our eyes may result in significant biological effects. For instance, many Pacific salmonid populations are augmented with hatchery fish. Yet it's now well documented that hatchery fish can be deficient in a number of traits necessary for survival. Is it possible that in our zeal to artificially augment wild stocks we've created populations lacking the competitive ability to retard invaders such as Atlantic salmon? Only time will tell. Atlantic salmon have been reared in B.C. for nearly two decades, yet no one has wondered what might happen if some escaped. The assumption of the public is that someone, sometime must have addressed the ecological issues prior to the importation of Atlantic salmon to B.C. But this is not the case. With the exception of my work, there are no scientific investigations whatsoever, past or present. We urgently need more science to address these issues before it's too late.

My work has shown that escaped Atlantic salmon are capable of surviving in the Pacific, do successfully spawn, and produce young that appear to be every bit as capable of surviving as their native cousins. A few fish here or there may not be a problem, who knows? But ask yourself this: If an eight kilogram female Atlantic salmon can deposit 15,000 eggs, how many spawners do you need in a river before you have a "problem"?

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John Volpe is a PhD candidate in UVic's biology department. His work

focuses on the ecology of invading organisms, particularly Atlantic salmon.

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