TRANSCRIPT - Robert Devlin
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.
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.
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.
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
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?
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.
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.
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
In the wild they're not going to survive longer, could you speak
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.
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
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
Is it part of this institution's priority or your own that wild
salmon populations need to be protected?
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.
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
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
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.
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?
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?
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
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
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.
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?
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.