When I entered the aquaculture industry in British Columbia in the late 80's, I was a veterinarian in private practice. I visited fish farms, looked at sick and dead fish, set up record-keeping systems and prescribed treatments. I did everything for the fish and the farmers that I did for my clients who raised cattle and pigs.

I was employing a system that has worked for generations for food animal production. I was applying science to manage the risks of rearing animals.

Soon, my work began taking me to various other countries around the world, where my knowledge and my company's products could be used to enhance production of food for domestic and export markets. The same system, the same science, helped support more and better food production around the world.

Somewhere along the way, however, life became increasingly difficult for my practice, my company and my clients in British Columbia, and the rest of Canada to some extent.

Salmon farming and aquaculture in general became a focus of controversy. Wild accusations were repeatedly thrown out. Fish farms were killing wild fish populations, killing whales, dumping antibiotics in the ocean, creating superbugs. Governments appeared to be listening to these diatribes! Where did all of this opposition come from? Why were governments passively or actively inhibiting aquaculture? Why has the aquaculture industry in BC been subjected to several inquiries over the past few years, including the Salmon Aquaculture Review: an environmental review of an entire industry?

In short, why has the growth of the aquaculture industry in Canada been severely restricted, when the system of managing risk, using the application of science, is accepted and works so well for other Canadian food animal production sectors and in most other countries?

That's why we're here for this conference, and I'd like to explore some of the issues in this presentation.

Our panels this afternoon will discuss science in aquaculture in the areas of Ecological Sustainability and Food Safety. I'll introduce some aspects of these topics, focusing on a few issues relating to health, diseases, treatments and veterinary science in aquaculture. My objective is to show you how science is being applied to manage risk and to safely and efficiently produce excellent food on fish farms in Canada and how, in spite of this, public policy, special interest groups, and abuse of science, inhibit or attack aquaculture.

ECOLOGICAL SUSTAINABILITY

Wild stock survival

There is no question that some stocks of wild fish in Canada are in trouble. Reduced catches and commercial fishing closures have hurt communities and individuals. There is increasing conflict among different fisheries sectors over access to remaining fish. In looking for reasons for the decline in fish numbers, it has been suggested that fish farming is responsible for some of the problem.

A recent examination of the role of aquaculture in the decline of Pacific salmon stocks notes that: "The most likely reasons for the decline in Pacific salmon stocks include a combination of climate change, overfishing, and freshwater habitat destruction." (Noakes et. al., 2000, On the decline of Pacific salmon and speculative links to salmon farming in British Columbia. Aquaculture 183, 363-386)

The survival rate in wild fish populations is extremely low compared with farmed fish populations. In wild Chinook salmon, estimates of survival several years ago were: 30% or less from egg to fingerling, 3% to 34% during freshwater residence and saltwater mortality rates were estimated to be in the range of 20% to 36% annually. (Healey, 1991, p 327, 340, 378) Coho salmon had smolt to adult survival rates estimated to be from 0.98% to a high of 19.1%. In one study, only 13% survived the first 6 months at sea and only 9% survived the first year. Of the survivors, half were killed in commercial and recreational fisheries, leaving 4% to return to spawn. (Sandercock, 1991, p 431)

The possible impacts on wild salmon by farmed salmon might include transfer of diseases or alteration of population genetics. Each of these will be discussed briefly.

Transfer of Diseases

Wild fish are not pristine - they get sick, have the same diseases as farmed fish (probably at higher rates) and are certainly exposed to a broader range of parasites.

A review of the pathogens known to affect wild salmon in BC emphasizes that "it's tough out there" for a wild fish. Surveys of pathogens in wild fish are not exhaustive but the known pathogens include:

Aeromonas salmonicida, Aeromonas hydrophila, Vibrio spp. and the human pathogens Vibrio vulnificus, Chromobacterium, Bacillus and Actinobacter spp. (Calderwood et al., 1988); Renibacterium salmoninarum, Myxobacteria, Motile Aeromonads, Fusiform bacteria, Yersinia ruckeri, Pseudomonas sp., Enterobacter sp., IHNV, VHSV, Acanthocephala, Anasakis, Costia, Eubothrium, Gyrodactylus, Hexamita, Trichodina, PKD agent, Phoma herarum, Caligus, Myxidium, Saprolegnia and others (Federal Fish Health Database – Fish Pathology Laboratory, Pacific Biological Station, January 1 to December 31, 1995).

The impact of disease caused by known pathogens can be estimated in farmed fish but is difficult to assess for wild fish. While the aquaculture industry spends considerable effort in monitoring fish and managing diseases, DFO as the lead agency for wild fish health and disease has suffered severe budgetary cutbacks to its science function. Our knowledge of wild fish diseases lags far behind what has been developed in farmed fish because our governments have not made the necessary commitments to programs that would investigate wild fish diseases.

There are significant barriers to the transfer of most pathogens between wild and farmed fish. These barriers are behavioural and physical. In order for disease to move from one population to another, there must be "effective" contact and the affected population must be influenced by the necessary factors that cause disease. It is important to note that infection is not the same as disease. Even if bacteria can manage to leave a farm fish, survive travel through the hostile aquatic environment and enter a wild fish, disease will not result unless the wild fish is impacted by other factors such as poor nutrition, predation, etc. Our experience in laboratory studies is that it is very difficult to induce disease in otherwise healthy fish just by infecting them with bacteria.

Genetic impacts

Just as wild fish are not pristine from a disease standpoint, wild populations are not genetically "pure" groups of animals. Indeed, it is genetic variation that is the key to survival of wild fish populations. Mixing of genetically different individuals is an essential component of stock and species survival, and salmon are very good at ensuring mixing and variation. The "straying" of stocks (returning to spawn in non-native streams), different life histories of families and individuals within families (freshwater residency, ocean migration), competition on the spawning grounds and production of a large number of progeny are examples of species strategies. The critical aspect of the risk of escaped farm fish on wild fish is the number of wild fish left in the stream. Escapees will not have a significant impact if the stream is filled with a genetically healthy population.(Peterson, 1999)

The genetic interaction of wild and farmed populations will be further discussed in other sessions. For now, it is interesting to note that the conjectures and fears regarding Atlantic salmon introductions into BC come at a time when Atlantic salmon are having great difficulty surviving in their home territories. It is a curious twist of logic to suggest that Atlantic salmon are in trouble in their home areas, Pacific salmon are not coping well with the environment in their home area, but that escaped Atlantic salmon in Pacific's territory will thrive. Atlantic salmon apparently left the Pacific thousands of years ago and, more recently, were wiped out in the Great Lakes. Pacific salmon, introduced into the Great Lakes, the largest watershed in Atlantic salmon territory, have thrived where Atlantics failed.

Indeed, it is more likely that: "Escaped farm Pacific salmon pose a greater potential risk given their ability to breed and interact with wild and hatchery salmon" and that: "Large-scale salmon enhancement projects have also resulted in significant ecological and genetic interactions with wild salmon, particularly for coho and chinook stocks." (Noakes et al, 2000) (Peterson, 1999)

In spite of the science and the actions by salmon farmers to manage these potential risks, aquaculture is still faced with negative press and lack of governmental support. For example, recent calls for utilization of closed or land-based fish farming systems represent an unworkable "solution" to problems that are not significant in the first place.

HUMAN HEALTH

Unlike other food sources, in which diseases or contaminants that can affect humans are an ongoing risk, farmed fish present very few risks. The major human health issues to consider in farmed fish are drug residues and antimicrobial resistant bacteria. On the other side of the equation are the health benefits we would obtain if we were to greatly increase our consumption of fish.

Antimicrobials in fish farming

No doubt, most have you have been exposed to controversies surrounding drugs in farmed fish, most them centred on antimicrobial use.

For about 50 years, antimicrobials have been available to treat bacterial infections in humans and animals. The lives of humans and the welfare of animals have been greatly enhanced by the use of these valuable disease management tools. Fish consume, absorb, metabolize and eliminate antimicrobial drugs similar to other animals and humans. Drugs are used for the same reasons and in the same ways as for any other animals, with the exception of growth-promoting antimicrobials which are not used in fish in Canada.

Human and animal welfare is profoundly affected, and improved, by the prudent use of a wide array of drugs. These are compounds that have a very limited range of activity, for the most part targeting one small aspect of what is going right or wrong in our bodies. We depend on these drugs to improve the quality of lives, treat deadly diseases or enhance productivity of food-producing animals.

Drug availability

We do, however, have a serious problem with drugs in fish culture in Canada. The problem is, we do not have access to enough drugs.

In Canadian fish farming, our range of available products is absurdly small. We have 4 antimicrobials, 2 anesthetics, a couple of fungicides and antiparasitics and that's about it. Contrast this situation with that described in Norway by Tor Horsberg. It is even worse when compared with other countries such as Japan.

How is that we have so few products available? The answer lies mainly with the Federal drug approval system. In 1992, a review of the Canadian drug approval system in Canada performed by Denis Gagnon observed that:

" ¼most other industrialized countries, such as Australia, Sweden, and members of the EEC have developed a more efficient model of drug review, that is becoming the world standard. It is time for us to come out of our traditional model, and adopt the more efficient one which will allow us to do the job, within the limits of our resources.

¼This approach has paid off: millions of Europeans have early access to new drugs, sometimes years before Canadian patients." (Denis Gagnon, Working in Partnerships¼Drug Review for the Future, Review of the Drug Approval System, July 1992)

Since Gagnon's report in 1992, the situation with veterinary drugs has deteriorated dramatically, even from the the bleak picture that Denis Gagnon reviewed. Recent data reviewing the performance of the Canadian veterinary drug regulatory agency, the Bureau of Veterinary Drugs (BVD), shows that the number of applications for new veterinary drug approvals has dropped from 43 in 1997 down to only 8 in the first half of 1999.

A few years ago, BVD, like many Federal agencies, instituted a fee for service approach to its work. Included in the changes were performance guarantees. Now, drug companies must pay fees to have their drug applications reviewed, but we were promised that the review would be completed within 180 days, and we could therefore service the industry and operate our companies more efficiently.

So what has developed under this new system? The fees are certainly in place! My company must pay 10's of thousands of dollars up front for reviews, or, if the product is expected to have low sales (as is the case for most fish products) we have the alternative option of paying the government 10% of our gross sales for 3 years. The performance part of the new system, however, has been dismal. In the first half of 1999, 100% of the drug reviews exceeded the 180 day performance promise. In 1999 it was taking an average of 926 days to accept a new product. Recent experiences put that figure well in excess of 1000 days. If I change the name of my company on the label, and nothing else, it now took an average of 278 days for BVD to process the change. On the vaccine side, the regulatory agency (CFIA) is also serious backlogged, with common approval times of 2 years instead of the 4 month service promise. In the human drug area, Canada is among the slowest in drug approvals, averaging 550 days.

The impact of this governmental dysfunction is that Canadian fish producers do not have access to new, safe and effective products that would enhance the industry and food production. Case studies prepared by the Canadian Animal Health Institute have shown examples of these impacts in other animal production sectors:

1. Approval of a cattle vaccine, submitted simultaneously in Canada and the USA, took 24 months in Canada and 3 months in the USA. In the time between US approval and Canadian approval, the sales in the US were $US 4 million. During this period, Canadian cattle producers continued to experience losses from a problem that the new vaccine was intended to solve, of just over $28 million annually.

2. A product for enhancement of growth in food animals took 6 years for approval in Canada, instead of the promised 180 days. The company lost in excess of 5 years of potential sales of the product, and the food animal producers lost the benefits that could have been provided during that time. An estimated 85% of the company's potential revenues for a 10 year product life were lost because of the delays.

Faced with these impossibly long delays in approvals, drugs that are critically needed by the industry are made available through provisional mechanisms. This process must be used for years, and has been the subject of recent criticism.

Clearly there is a strong incentive for Canadians to solve our drug regulatory problems.

Governments' role

Apart from the performance problems I have mentioned, the drug approval systems in Canada, the US and EU, for the most part, are accepted by the public as a means of protecting them. In fact, as discussed, the requirements are so onerous that very few new products are available. Antimicrobial drugs are chemicals that have a well understood and limited realm of activity, and are safe compounds. Essentially, people do not get sick from drug residues in fish or other Canadian animal food products.

However, special interest groups have taken advantage of Federal and Provincial governments' lack of expertise, commitment and responsibility toward the aquaculture industry to attack drug use in the industry. Aquaculture has lacked the proponent agencies who would have immediately debunked, or at least not listened to, the hysterical criticisms. The Bureau of Veterinary Drugs has no particular knowledge or expertise in fish, the food inspection agency, CFIA, has had a mixed and evolving mandate regarding fish products, and DFO has been in the impossible position of concurrently trying to regulate, conduct research and promote aquaculture along with "competitive" wild fish sectors. These internal conflicts render DFO an ineffective lead agency for the aquaculture industry. The BC NDP government has let aquaculture bounce around while it plays to its union supporters in the wild fish industry and attempts to deal with aboriginal rights issues (among others!).

In reality, antimicrobial use in fish in Canada is an exemplary model of responsible actions by farmers, veterinarians and pharmaceutical companies. Claims of human health dangers related to drug use in fish in Canada are seriously misplaced.

Antimicrobial resistance

The contribution by farmed fish to the problem of human infections by antimicrobial resistant bacteria is minimal. Fish are not significant sources of human pathogens. The important species of bacteria that are of most concern, the zoonoses, such as E. coli, Salmonella, and Campylobacter are not really found in fish, especially farmed salmon. Bacterial pathogens of humans like to grow at our body temperatures, and don't do well at the temperature ranges in which our salmon grow.

Antimicrobial treatments do not "create" resistant bacteria. Treatments on fish farms do not "create" fish pathogens that are resistant to drugs. Bacterial populations naturally contain individuals that are resistant to certain drugs and these individuals will remain when the drug is used. They have been selected, not created. The normal population make-up will return when the drug is no longer around to force selection of resistant bacteria.

A potentially significant source of contact with resistant pathogens is the feces or fecal bacteria of other people or animals. As much as 50% of the feces of mammals can be bacteria. Again, fish feces does not contain large numbers of zoonotic bacteria, and people are not likely to contact fish feces.

The major source of the risk must be addressed by the medical profession. "In general, there is little doubt that treatment problems in humans due to resistant bacteria are primarily related to the prescribing practices of health workers and to medication-taking practices of patients." (WHO, The Medical Impact of Antimicrobial use in Food Animals. WHO/EMC/ZOO/97.4)

In spite of this very low risk of contributing to the problem of antimicrobial resistant bacterial infections in humans, the fish farmers and veterinarians in Canada have adopted a range of measures to manage what risk there might be. The activities are directed toward ensuring the prudent use of antimicrobials.

Prudent use of antimicrobials

No other sector of our society using antimicrobial drugs acts as responsibly or is monitored as closely as fish farming in British Columbia. In BC, all veterinary prescriptions for drugs in fish feed are recorded, compiled and analyzed by the BC Ministry of Agriculture, Fisheries and Food. These data demonstrate the tight controls on antimicrobial use in farmed fish, imposed by government but also voluntarily by the farmers and the veterinarians. Here is the true situation in BC, in 1999:

• 100% of antibiotics in aquaculture feeds were prescribed by veterinarians
• 99.87% of the products used were licensed by BVD for use in food fish (the remainder were licensed for use in other species)
• 96.96% of the antimicrobials were used in fish less 2000 grams (that is, many months away from harvest, well beyond the mandatory withdrawal times)
• 96.04% of the use was oxytetracycline
• 9 grams of Ivermectin was used
• (no antimicrobials are used for growth promotion)

(data from Manager, Health Management & Regulation, Animal Health Branch, BC Ministry of Agriculture, Fisheries & Food, August 12, 2000)

These data compare favourably with the situation described in Norway. Information prepared by Mark Sheppard (Antibiotic Use in BC Aquaculture (1996-1998); Is the comparison with Norway realistic?, Presentation to Standing Committee, 2000) points out that Canadian fish farm infectious disease problems are mainly caused by bacteria, while Norway faces more problems from parasites and viruses, for which antimicrobial treatments are not used. In addition, bacterial problems in Pacific salmon generally occur later in their life, requiring a larger quantity of antimicrobial per treatment than for smaller fish. A final point of difference is that in Canada we use oxytetracycline commonly in place of the oxolinic acid more often used in Norway. Oxytetracycline is less potent by weight than oxolinic acid, so a single dose is 6 to 10 times higher. That is, we could cut our antimicrobial use by 1/6th to 1/10th just by using drugs that are not available in Canada but used elsewhere.

The true picture of drug use in farmed fish, as you can see, is quite different from what you may have gathered from media reports. Much of this responsible use is directed by the veterinary profession. Veterinary prescriptions represent a proven effective control point on drug use and protection of food safety. This system works well for all food-producing animal industries, including fish.

Veterinarians, and their regulating professional associations, approach antimicrobial use and effects cautiously and responsibly. Recent publications by the Canadian Veterinary Medical Association are indicative of this and make good reading for those interested:

CVMA Guidelines of the Prudent Use of Antimicrobial Drugs in Animals

Antimicrobial Resistance: the Canadian Perspective, Information for the Practising Veterinarian

Superbugs and Veterinary Drugs

Web Sites for information on antimicrobial resistance

Other practices also help to manage the risk associated with resistant pathogens, including:

treatments are based on cultures of the bacteria causing illness in the fish and tests for which antimicrobial is effective against the culture

veterinarians and farms try to rotate the drugs used, so that bacterial populations on a farm are exposed to different drugs and are less likely to be selected for resistance to a particular drug

oxytetracycline, the most commonly used antimicrobial in fish in Canada, is rendered inactive in seawater because of binding with minerals in the water and sediment; environmental bacteria are not exposed to low doses of oxytetracycline

food inspection procedures employed by CFIA, and compliant with USFDA HACCP guidelines, ensure that approved drugs are used in farmed fish and the prescribed withdrawal times before harvesting are observed so that bacteria in people are not exposed to low levels of antibiotics that might encourage resistance

when medicated feed is provided to fish, consumption is closely monitored, for example with underwater cameras, to ensure that it is all eaten by the fish

RESPONSIBILITY

I trust that this presentation has provided you with a glimpse of the aquaculture industry and the way that Canadian farmers and veterinarians have taken a cautious and responsible approach to managing risks. We have applied science to manage the risks, and are probably doing as well as, or better than, any animal production industry I know of anywhere.

Periodically, I step back from my day-to-day activities to monitor what I, and the industry, are doing and accomplishing. I ask myself if my activities are responsible and if I am helping to produce benefits for society. I would suggest that if other sectors of our society would conduct a similar exercise, there would be more support for aquaculture in Canada.

Some of the environmental special interest groups would recognize that their attacks on aquaculture are misplaced. Driving aquaculture out of Canada would lead to replacement of wholesome Canadian fish with less suitable protein sources or imported seafood over which we have far less control. I would certainly prefer that my family eat farmed salmon than an organic vegetable product fertilized with raw manure and handled by someone shedding Salmonella!

The news media would no doubt generate fewer negative or inflammatory pieces if they acted with a broader, balanced approach as Knowlton Nash suggests:

"The news media are not simply spectators at issues and events. We journalists are participants because we identify those issues and events for others. We choose the ones we consider significant and set others aside. We hold a mirror up to society, but we do so selectively. We have to recognize that the simple act of raising that mirror changes the character of the event or issue by intensifying, glamorizing, or denigrating it. We must be as sure as we can that we are giving a fair reflection of reality and truth when we raise that mirror.

We're not giving truth a fair chance if we are adversaries in our news stories, if we sensationalize, if we're lazy or careless or unscrupulous if we're shallow or simplistically looking only for good guys and bad guys. We must look not only for the obvious, but for the nuances and subtleties of complex situations." (Trivia Pursuit. McClelland and Stewart 1998)

In similar fashion, governments in Canada would, and should, recognize the value of the aquaculture industry. Aquaculture is a small, loosely organized industry and members of the industry are busy trying to build the industry. Governments have fallen prey to the messages from other, well-organized and funded groups that have agendas quite different from efficient food production and wealth-creation in Canada.

I hope that this conference and the following panel sessions capitalize on an opportunity to hear about the real benefits of aquaculture and how we are successfully managing risk through application of science. We can grow great fish and produce nutritious, safe food. Let us get on with it!