Bob Devlin is a research scientist with Fisheries and Oceans Canada at the West Vancouver Laboratory.


Why are you, with public money, experimenting with accelerating the growth rate of salmon by genetic alteration.

The purpose of our research is to develop living model systems for genetically engineered animals that will allow us to do research and hopefully obtain meaningful scientific data that will help resolve many of the questions or some of the questions in this area.

The purpose of the research here is to develop genetically engineered fish to help us in risk assessments. This is a very complex question of course today, and there's very little scientific data available to help us break through some of the rhetoric and many of the questions that exist regarding the risk of these fish if they were to escape into the natural environment. So our program here is to develop genetically engineered animals, to use them in a contained facility to conduct experiments and to generate data and provide that data in an open and objective way to the public.

The research we've undertaken is to overexpress a gene that produces growth hormone. This is a hormone that controls growth in the fish. By producing an elevated level of growth hormone, from cells throughout the body, the fish respond quite dramatically and end up, uh, growing about two to three times faster per day than a regular fish.

The research that we're undertaking is to develop genetically engineered CoHo* salmon that contain growth hormone genes. The genes have been modified in the lab to allow them express higher levels of growth hormone. This hormone is very closely involved in regulating the growth of fish. The fish that have been genetically engineered end up growing about two to three times faster on a daily basis than normal, non transgenic fish.

What is the main reason that you are doing this?

The main reason for our research is to provide scientific data that will hopefully be able to break through much of the rhetoric and the speculation and questions that exist regarding the risks of genetically engineered fish for their potential effects on the natural environment.

What is the advantage to the industry to have a faster growing fish?

Genetic engineering does have a lot of potential to assist aquaculture and one of the major factors that influences the profitability or survivability of aquaculture production is the growth rate and feed conversion efficiency associated with production of fish in aquaculture.

Acceleration of growth by a number of different technologies can improve the efficiency of production by as much as ten to twenty percent and this could of course be very significant. Reducing the time required to produce a marketable fish, we realize that at least here in North America and in particular in British Columbia our aquaculture association has quite clearly stated that at this time they're not interested in transgenic technologies for aquaculture.

Are you creating Frankenfish?

No. Frankenfish is a term that I think serves essentially no purpose in this in this area of complex scientific debate. Really what is required I think for the benefit of the public is for us to generate as solid set of scientific data as we can,

To have that publicly available for scrutiny, have it peer reviewed in scientific journals, and to allow a logical assessment of the information rather than to prime the discussion with words such as Frankenfish which of course are inflammatory and are designed to execute a particular consequence to a discussion. I think we should look at things quite objectively, to try and let the scientific data drive the conclusions.

A lot of people think "Giant GM Fish, Little Natural Fish". Is that a misconception?

We are not producing large fish; we're producing fast-growing fish. This is also the case for the people that're involved in the commercial production of transgenic fish. We're accelerating growth rate but in our case with the model system that we've developed with Coho salmon, the salmon actually only reach normal adult size, they just do so in a shorter period of time, reaching sexual maturity in two years rather than three or four years in the laboratory environment. So we're not making big fish, we're making fast-growing fish. Nevertheless that fast growth has really profound potential implications for what those fish could do if they were to be present in the natural environment.

In the wild they're not going to survive longer, could you speak about that?

The potential survival of a transgenic fish in nature is really dependent on its fitness relative to a non-transgenic wild version. Fitness has two components: how well you survive to maturity; and if you do, how well you re- reproduce and pass your genetics on to the next generation. So we've looked at a number of aspects in this area to try and assess what the fitness of the animals might be. There are a whole suite of active factors. For example in survival, disease resistance has been looked at and seems to be suppressed in the transgenic fish. Foraging ability for food is enhanced in the transgenic fish this would potentially give them an advantage.

However, that foraging ability also pro-produces a tradeoff in that their predator awareness is much reduced. So this is the kind of information we're generating in terms of survival data. In terms of reproduction, we've done spawning trials. A graduate student Cindy Bessie has done a nice series of stu! dies to look at their reproductive performance in competition between transgenic and non-transgenic fish and found in most cases that the non-transgenic fish are far superior at spawning than are transgenic fish. So by taking this information in the area of fitness for survival and reproduction, we are starting to build up a body of information that is helping us understand the characteristics of the fish relative to wild fish.

Now the main difficulty with this risk assessment process is how well and in what level of confidence do we have in that laboratory information for translating it into a meaningful risk assessment conclusion for fish that might be in the natural environment. And at the moment my level of confidence is quite low actually. I think this is a major issue that we need to face both in the scientific arena and also the regulatory arena for producing control systems that are very robust and conservative.

One of the concerns that we have with the research that we're undertaking is how well do laboratory data that we generate; how would they apply to the situation in nature. And of course the two environments are very different so we suspect that results would also differ. At this point we don't know the answer to that question which has to leave us in a situation where we have to be conservative in terms of our conclusion about the risks.

In laboratory conditions, these fish weren't surviving. They weren't spawning as well, and they weren't surviving as long in terms of dealing with predators. What's the problem here?

The issue of whether or not the laboratory data is applicable to nature is an extremely complex one that exists in many fields. The question is what level of confidence do we have in that data? I can speculate based on the laboratory information about the consequences. But, from an ecological point of view, can we conclude from that information? I have not been able to do it with the strains that I have available. To me the natural ecosystem of the North Pacific Ocean is incredibly complex. I don't purport to be able to take my information and translate it into that complex ecosystem with certainty to come up with a conclusion on risk.

Is it fair for scientists who are employed by the industry to try to give the public the impression that these lab tests hold true in nature?

I cannot say that they don't hold true. That's where we're at a dilemma. We don't know the answer. That's where we have to decide which course of action to take. Because there's uncertainty, we have to think about alternative means of protecting the environment, and the clearest one for that approach is containment - either physical or biological containment approaches.

Is it part of this institution's priority or your own that wild salmon populations need to be protected?

Definitely, the Department of Fisheries and Oceans, one of its main mandates is to ensure the protection of wild stocks. The transgenic fish program is being allowed to occur at the Department of Fisheries and Oceans to allow us to generate data that potentially will protect the wild fish in the future. Now currently there are no requests for the use of the transgenic fish before our government for regulatory purposes, but we anticipate that this may well occur in the coming years. We want to be in a position where we actually have experience and scientific data to debate that question, and also really understand the uncertainties of the information that might be presented to us in terms of regulation.

We consider how solid that information is, what kind of variables might influence the types of data that might be presented to us and how, and how well does that will translate to what would happen in the natural environment. What we really need is risk assessment data from transgenic fish that have lived their entire life in nature. We don't want that to ever occur either from a commercial, natural situation, or from a research perspective. So, the fact that we have limitations associated with the laboratory data is just a necessary consequence of maintaining the fish in a contained environment. That's the best that we can do to obtain that kind of laboratory information.

Why is it a priority to protect wild salmon, in your opinion?

They're a very important part of our social structure and our heritage and the First Nations' heritage as well, so it's just critical to do that. They're also excellent beacons of the general health of our natural ecosystems. To protect groups of organisms like that is a social responsibility. From a commercial perspective, people argue that aquaculture is definitely the way to go and to relieve pressure on the natural stocks by allowing them to be available to First Nations, limbic commercial fishing, and sport fishing. But, those are very complex policy decisions that I'm not really involved in.

One of the strategies for containment would be sterility. How absolute are you that you can make these fish sterile?

One of the approaches for containment is sterilization of the animals. The most effective way of doing that currently is to induce triploidy. This is an animal that has three sets of chromosomes normally, rather than two. This occurs rarely in nature, but you can induce it to high frequencies in the laboratory and the fish end up being completely sterile. What the issue then becomes, from a risk-assessment point of view, is how effective is that induction process for triploidy. We have not been able to achieve 100% triploidy. In groups of up to fifteen thousand fish we see failure rates on the order of 0.1% to 0.2%. So there are low levels but still significant levels of failure of triploidy. These failed individuals are diploid and fully fertile animals that could grow up and reproduce in nature if they were to escape from a net pen situation.

It's such a tiny percentage. What's the problem with that?

The reason that even a low frequency of fertile individuals, being released into a natural situation may be a problem is that we really don't understand the fitness of those animals.If they have a fitness advantage in nature and there were even a low number of them introduced, they had an advantage and were able to breed, it would delay the impact that they may have. Ultimately, the population would experience very similar consequences.

The frequency affects time, until there is a consequence, rather than what the consequence is. There are some escaped fertile individuals in triploid populations, at least in our experience.This gets back to the laboratory studies that we do. We really need to have the best information available about those in terms of their spawning ability, survival, predation ability, and disease resistance. This gives us the best chance to predict their fitness in nature, even if there is a great deal of uncertainty associated with it.

Why is that a problem for wild salmon?

For example, if fifty thousand fish escape from a net pen and 0.1% are going to be fertile, there are fifty fertile animals that are going to be available in nature to interact with the natural stocks. This is still a significant number of animals that could potentially initiate an impact.

Are genetically modified fish the future of the industry?

Whether genetically engineered fish will be adopted by the aquaculture industry I think in the short term largely depends on society's acceptance of genetically engineered foods in general. That debate is still somewhat open, although we're seeing a gradual transition to the North American population being accustomed to consuming transgenic or genetically engineered foods. In the future, it's possible that transgenic fish will be adopted. This depends to a large degree on our ability to generate safe regulations, minimize or eliminate impacts on the environment, and seeing if the public will accept the technology.

To what degree does the biotech industry need to be regulated and monitored?

The biotech industry should be allowed to develop new technology. There's enormous potential in this area. A role for government research is to help alert them to potential issues that they need to face to make sure that the technology can be implemented in a safe way to protect the public interest. My objective really is to not only do risk assessment research, but to help come up with a solution so that we can adopt this kind of technology and other technologies in a safe manner, if that can be done.

So, it's not ready for prime time yet?

Yes, I can't say that for their fish but I can say it for our fish. The experience that we've had with our fish to date suggests there are a few problems that might be encountered regarding the commercial application of them. I want it emphatically stated that in no way are we involved in commercial development of transgenic strains but we're investigating the aspects and characteristics of the fish. One of the observations that we've seen are some abnormalities in the fish which in some cases have been quite profound.

Some strains are quite normal. But the other factor that we've noticed is that transgenic fish, while they grow very rapidly relative to their non-transgenic wild siblings they don't perform, in terms of growth, as dramatically better than the current existing domesticated strains that are used in aquaculture. The important criteria, that will determine whether or not an aquaculture industry would adopt a new technology independent of the social issues, is how effective is that technology relative to current strains that they have available.

In our case the domesticated strains of Coho salmon that are available already perform quite well, not as well as our transgenic strains, but when we induce sterility or triploidy in our transgenic strains, it actually reduces the growth performance of our transgenic strains. It reduces them down to the level of growth seen in the current domesticated strains used in aquaculture.

You said there have been some abnormalities. Can you give us some examples of those?

One of the most obvious abnormalities that we've observed are cranial deformities and this is something that actually occurs in all mammals when over-expression of growth hormone occurs. One can get excessive production of cartilage and bone. So the fish's head can actually develop quite bulbous growths of cartilage, over-growth of the gill cover and disruption of the fins. So these deformities can be quite significant.

Why are you doing it? We know what you're doing, but why?

The objective of our research is to generate objective scientific data that's publicly available to help in a risk-assessment process. There's really a great deal of rhetoric and speculation about the dangers and benefits of this technology, but precious little scientific data to help resolve the dilemma.