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The Vancouver Sun
Wed 22 Mar 2000
Scientists put extra genes in salmon for growth:
Researchers say they
can grow fish to maturity in half the normal time, but add that many questions
remain to be answered.
The young coho salmon swimming in the vat look pretty much like any other
of
their species, Oncorhyncus kisutch. They have the same bluish sheen, the
same
black spots scattered along their backs, the same white-gummed grimaces.
But
these fish are definitely different.
For one thing, they're about three times longer than the average one-year-old
coho and about 30 times heavier.
These particular young coho are some of the thousands of ** genetically
modified fish at the department of fisheries and ** oceans' West Vancouver
Research Laboratory. They differ from their unaltered, wild brethren in
that
they have extra genes, genes put ** there by scientist Bob Devlin and
his
colleagues.
The genes, which regulate growth, came from other salmon. They were injected
into a batch of coho eggs. As the new fish grew, their genes incorporated
the
introduced DNA.
(At maturity, both kinds of salmon will be about the same size -- between
2.5
and 5.5 kilograms. But the normal coho will have taken four years to get
there,
the transgenics only two. Some of the earlier generations of transgenics
also
had misshapen heads, their gills lumpy and distorted, their usually
streamlined
profiles humped with excess cartilage.)
Devlin began his research into transgenics in 1989. He was looking at
the
potential of genetic engineering for application to ** fisheries science.
Then
companies worldwide began looking at
producing genetically modified fish on a commercial basis. In the **
early
stages, DFO officials considered a collaboration with industry. But after
much
discussion, the decision was made to focus the research solely on risk
assessment.
``The department decided that receiving money from licensing and
commercialization would complicate the research,'' says Devlin. ``By doing
it
totally within the government we're able to keep it totally objective.''
(The only Canadian company involved in commercial transgenic research
is A/F
Protein Canada Inc. of Newfoundland. Their experimental hatchery on Prince
Edward Island is working on producing faster-growing Atlantic salmon,
trout
and
Arctic char.
These days Devlin and associates work with two species: coho salmon and
rainbow
trout. Their aim is to understand as much as possible about the fish that
result from the transgenic process.
The idea is not just to increase scientific knowledge but also to establish
regulations for the inevitable commercial applications.
``Once you have actually grown the fish and seen them you realize that
there
are quite a lot of questions to be asked,'' says Devlin.
There is increasing public anxiety about genetically modified foodstuffs
--
both plant and animal. Those for and against are waging a war of words
in
newspapers, magazines and on Web sites.
Others, more radical, have vandalized crops and projects that they believe
to
be genetically modified.
Earlier this month, a New Zealand company suspended its attempt to grow
bigger
chinook salmon. Opponents of the project had fought for more than a year
to
shut it down, after leaked reports of deformed heads and other
abnormalities in
the transgenic fish. (All the fish were destroyed, but the company has
frozen
the genetically modified sperm for possible future projects.)
And in January, 138 countries signed a United Nations-sponsored Biosafety
Protocol in response to consumer concerns about health, safety and ecological
impacts posed by genetically modified organisms. The protocol now forces
exporters to label shipments that may contain added genetic material.
The
protocol applies only to agricultural products such as corn, soybeans,
cotton
and wheat.
Devlin says there is still much more to be learned about transgenic fish.
His
particular concerns focus on two areas: human food safety and environmental
concerns.
He's pretty confident that food safety issues can be adequately addressed.
Research so far on transgenic salmon shows no problems. But, he adds,
there
are
still questions to be answered.
Then there's the issue of environmental impact, namely what effect would
transgenic salmon have on B.C.'s marine ecosystem should they escape into
the
wild?
``When you see this kind of size difference after one year,'' says Devlin,
``you've got to start to think that this might have some impact.''
Research shows that genetically modified fish don't swim as well as normal
fish. On the other hand, transgenics have voracious appetites -- they
eat
about
10 times more than normal fish the same age, three times more even than
normal
fish the same size.
Scientists know that transgenic and wild salmon can interbreed -- at
least in
the lab. But they don't know if transgenics can survive the rigours of
spawning
in the wild.
It's also known that transgenic fish hatch sooner than normal fish. But
the
salmon's life cycle is timed to other cycles in nature -- the hatch of
insects,
for example. So it's not known if such a trait would be an advantage or
a
disadvantage.
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