A Purdue University scientist is urging federal officials to decide favorably on allowing genetically engineered salmon into the food supply arguing that not doing so may set back scientific efforts to increase food production. The argument comes in direct contradiction to statements made by the same scientist who found that releasing a transgenic fish to the wild could damage native populations even to the point of extinction.
Research on GM trout in Canada found that while they grew faster and were many times larger than the wild species, they were likely to die before maturity and a number developed deformed heads and bloated bodies.
Genetic engineers at Aqua Bounty, a company based in Waltham, Massachusetts, have been manipulating fish growth hormone to make the GM salmon grow more quickly. This involves taking genes from the ocean pout and the chinook salmon, which trigger the release of growth hormone in the GM fish during their development.
William Muir, a professor of animal sciences, said that based on data made available by the U.S. Food and Drug Administration, AquAdvantage (AA) salmon poses little real risk to the environment or human health. AA salmon were given a gene from Chinook salmon that speeds growth and improves feed efficiency in farm-raised fish.
Developed by AquaBounty Technologies, the fish would be spawned in Canada and grown to full size in Panama, both of which are land-based, contained facilities.
Muir and Alison L. Van Eenennaam, an animal genomics and biotechnology Extension specialist at the University of California Davis, made the call for FDA approval in a peer-reviewed commentary in the early online version of the journal Nature Biotechnology.
The salmon would be the first genetically engineered animal used as a food in the United States, but it has been tied up in FDA regulatory proceedings since 1995. Muir said that becomes a disincentive for those working to increase food supplies for a growing world population.
"This tells us that no entrepreneur is going to invest in these new projects because they can't get them approved," Muir said.
Muir has not received any funding or support from AquaBounty Technologies, however his motives are questionable considering statements he made a decade ago which contradict his current position.
In early 2000,
Muir and biologist Rick Howard used minute Japanese fish called medaka to examine what would happen if male medakas genetically modified with growth hormone from Atlantic salmon were introduced to a population of unmodified fish. The research was conducted in banks of aquariums in a laboratory setting.
The results warned that transgenic fish could present a significant threat to native wildlife. "Transgenic fish are typically larger than the native stock, and that can confer an advantage in attracting mates" Muir says. "If, as in our experiments, the genetic change also reduces the offspring's ability to survive, a transgenic animal could bring a wild population to extinction in 40 generations."
Extinction results from a phenomenon that Muir and Howard call the "Trojan gene hypothesis." By basing their mate selection on size rather than fitness, medaka females choose the larger, genetically modified but genetically inferior medaka, thus inviting the hidden risk of extinction.
The viability of groups of modified and conventional fish were measured at three days of age, and 30 percent fewer transgenic fish survived to that age. The researchers calculated that large males had a four-fold mating advantage, based on observations of wild-type medaka. Computer models then were used to predict the consequences of the transgenic mating advantage combined with the reduced viability of the young.
Wildlife specialist Marcus Benefatto said "this would directly affect wildlife populations as a whole if such species where to be introduced into ecosystems." Benefatto's concern is that no long-term testing or species introduction has ever been studied. "The results could be extremely dangerous to wildlife, the environment and human health."
Benefatto claims that Muir was coached and coaxed by agribusiness to
change his earlier position which insisted that the introduction of genetically engineered salmon into the wild salmon population would cause its extinction. "He has been approached by other interests who do not have human health and the environment as a first priority and this is clear."