Fwd: Research on gene-altered fish

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" News Update from The Campaign "

Research on gene-altered fish

Wed, 16 Jun 2004 05:18:49 -0500

 

News Update From The Campaign to Label Genetically Engineered Foods

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Dear News Update Subscribers,

 

Last week, the Proceedings of the National Academy of Sciences featured an

article titled " Population effects of growth hormone transgenic coho salmon

depend on food availability and genotype by environment interactions. " In

other words, a new report was released on genetically engineered salmon.

 

The Seattle Times has written an article on the findings of this disturbing

report that has been picked up by other newspapers across the country.

 

Posted below is the Seattle Times article titled " Research fuels fear of

gene-altered fish. " It explains the threat that these " frankenfish " could

pose to other fish if the Food and Drug Administration (FDA) approves them

for commercial production.

 

Also posted below is the scientific abstract about the report from the web

site of the Proceedings of the National Academy of Sciences

 

Craig Winters

Executive Director

The Campaign to Label Genetically Engineered Foods

 

The Campaign

PO Box 55699

Seattle, WA 98155

Tel: 425-771-4049

Fax: 603-825-5841

E-mail: label

Web Site: http://www.thecampaign.org

 

Mission Statement: " To create a national grassroots consumer campaign for

the purpose of lobbying Congress and the President to pass legislation that

will require the labeling of genetically engineered foods in the United

States. "

 

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Research fuels fear of gene-altered fish

 

By Sandi Doughton

Seattle Times staff reporter

 

In a head-to-head battle for food, normal coho salmon lose out to their

genetically engineered cousins, says a new study that adds to the

controversy over what critics call " frankenfish. "

 

Not only did the aggressive, gene-modified salmon gobble up most of the feed

when raised in tanks with ordinary salmon, but they also gobbled up their

weaker competitors — including their own type, British Columbia scientists

reported in yesterday's online edition of the Proceedings of the National

Academy of Sciences.

 

The results were often dramatic population crashes, with only one or two of

the genetically modified fish surviving in tanks that originally held 50

animals, said lead author Robert Devlin of Fisheries and Oceans Canada.

 

" When food supplies are low, transgenic (genetically modified) fish have a

very significant effect on the population, " he said, adding the caveat that

laboratory experiments may not predict what would happen if bioengineered

salmon escaped into the environment.

 

But that's a question that needs to be answered soon.

 

Massachusetts-based Aqua Bounty Farms has asked the U.S. Food and Drug

Administration for approval to market what could be the first transgenic

food fish: Atlantic salmon that grow twice as fast as normal fish. Aqua

Bounty hopes to raise its transgenic salmon in coastal net pens in the

United States and market the eggs around the world, said Joseph McGonigle,

vice president for external affairs. " We are constantly hearing from

companies that are interested in it, " he said.

 

Faster-growing salmon would cut costs dramatically for fish farmers and lead

to lower prices in the supermarket, McGonigle said.

 

Consumer groups, commercial fishermen and some scientists say studies such

as Devlin's show the potential ecological consequences of unleashing

man-made breeds of fish.

 

" We should not be taking a risk like this at a time when native salmon

stocks are already in trouble, " said Doug Gurian-Sherman, senior scientist

at the Center for Food Safety, a consumer group based in Washington, D.C.

 

A 2002 National Academy of Sciences report expressed moderate concern that

genetically engineered fish might pose risks to consumers if, for example, a

person who was allergic to scallops ate fish with a scallop gene spliced

into its DNA. But experts agreed that the biggest danger is that some of the

gene-modified fish would inevitably escape into the environment.

 

Hundreds of thousands of Atlantic salmon have escaped into Northwest waters

from salmon farms over the past several years when floating pens were ripped

apart by storms or marauding sea lions.

 

The worst-case scenario involving transgenic fish is the " Trojan gene "

hypothesis proposed by Purdue University geneticist William Muir:

Genetically engineered salmon outcompete normal fish for food and mates,

leading to less-hardy hybrids and the eventual extinction of the entire wild

population.

 

McGonigle says the net pens would hold only sterile females, eliminating the

possibility that escapees could breed in the wild. Several other studies,

including some in Devlin's lab, have shown that the genetically engineered

fish aren't likely to survive well outside of captivity because they're more

susceptible to disease and oblivious to predators.

 

" We realize we have no chance of getting approval unless we can clearly

demonstrate these fish are completely sterile, and they represent no genetic

threat and no behavioral threat, in terms of competition for resources, " he

said.

 

Washington's Fish and Wildlife Commission banned genetically engineered fish

from marine net pens, but the state has no rules that bar them from

land-based tanks or fresh water, said John Kerwin, who manages the state's

hatchery program. Oregon has similar restrictions, while California bans the

creatures entirely — including the fluorescent Glo Fish, a genetically

engineered aquarium fish that went on sale last year.

 

Devlin's research for the Canadian government is attempting to unravel the

possible impacts of genetically engineered food fish before they're

approved.

 

" We're just starting to gather the kinds of laboratory information which we

hope will provide us with understanding about these animals, " he said.

 

He works with coho salmon that overproduce growth hormone as a result of

genetic tinkering. Aqua Bounty's Atlantic salmon were engineered in a

similar way, using genes from chinook salmon and a species called ocean

pout.

 

In both cases, the genetically engineered fish grow much faster than

ordinary fish but don't get much bigger at maturity.

 

At 1 year of age, Devlin's gene-engineered fish are 10 times the size of

ordinary coho.

 

For the study reported yesterday, Devlin and his colleagues manipulated the

amount of food available to the fish. When food was abundant, normal and

genetically modified fish coexisted well. It was only when food was scarce

that competition turned deadly for the normal fish.

 

While populations made up only of normal fish were able to ride out food

shortages, mixed populations invariably crashed.

 

But the experiments also revealed another wrinkle: Populations made up of

only genetically engineered fish also crashed when food supplies were low.

 

Does that mean transgenic fish might pose little risk if they escaped into

the environment because they would die out when food supplies drop?

 

It's possible, Devlin said.

 

" If you had a small population, where the fish couldn't migrate out of the

area, transgenic fish might eat themselves out of house and home and there

would be no risks, " he said.

 

But on the other hand, if numbers boomed when food was plentiful, the

bioengineered fish could devastate normal fish in the cutthroat competition

that would ensue.

 

McGonigle says he hopes to have an FDA ruling within the next two years, but

the target date has been pushed back repeatedly.

 

Because of regulations to protect businesses, the agency's evaluation

process is largely secret, leading critics to call for a new system that is

open and gives more authority to environmental and wildlife agencies.

 

" FDA has absolutely no experience with these kinds of issues, " said

Gurian-Sherman, the Center for Food Safety scientist. " And we know nothing

about what they're doing. "

 

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Published online before print June 10, 2004

Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0400023101

www.pnas.org/cgi/doi/10.1073/pnas.0400023101

 

Ecology

Population effects of growth hormone transgenic coho salmon depend on food

availability and genotype by environment interactions

 

Robert H. Devlin *, Mark D'Andrade, Mitchell Uh, and Carlo A. Biagi

Fisheries and Oceans Canada, 4160 Marine Drive, West Vancouver, BC, Canada

V7V 1N6

 

Edited by Wyatt W. Anderson, University of Georgia, Athens, GA, and approved

May 5, 2004 (received for review January 2, 2004)

 

Environmental risk assessment of genetically modified organisms requires

determination of their fitness and invasiveness relative to conspecifics and

other ecosystem members. Cultured growth hormone transgenic coho salmon

(Oncorhynchus kisutch) have enhanced feeding capacity and growth, which can

result in large enhancements in body size (>7-fold) relative to

nontransgenic salmon, but in nature, the ability to compete for available

food is a key factor determining survival fitness and invasiveness of a

genotype. When transgenic and nontransgenic salmon were cohabitated and

competed for different levels of food, transgenic salmon consistently

outgrew nontransgenic fish and could affect the growth of nontransgenic

cohorts except when food availability was high. When food abundance was low,

dominant individuals emerged, invariably transgenic, that directed strong

agonistic and cannibalistic behavior to cohorts and dominated the

acquisition of limited food resources. When food availability was low, all

groups containing transgenic salmon experienced population crashes or

complete extinctions, whereas groups containing only nontransgenic salmon

had good (72.0 ± 4.3% SE) survival, and their population biomass continued

to increase. Thus, effects of growth hormone transgenic salmon on

experimental populations were primarily mediated by an interaction between

food availability and population structure. These data, while indicative of

forces which may act on natural populations, also underscore the importance

of genotype by environment interactions in influencing risk assessment data

for genetically modified organisms and suggest that, for species such as

salmon which are derived from large complex ecosystems, considerable caution

is warranted in applying data from individual studies.

 

*To whom correspondence should be addressed.

Robert H. Devlin, E-mail: devlinr

 

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