viernes, 10 de septiembre de 2010

Super salmon growth fast and cost less

Chilean and Norwegian advantage in high risk

In a nation that loves big stuff--from cars and certain body parts--you'd think people would be pretty excited about a new line of fast-growing farmed fish.

A new salmon technology arises when a researcher in Newfoundland froze a tank of flounder. To his surprise, the fish survived, and further research led scientists to discover an "antifreeze gene" that is part of the DNA of cold-water fish.

Scientists initially hoped to use that gene to develop a strain of Atlantic salmon that could be farmed in icy Canadian waters. As gene-splicing techniques were developed, they learned that the same gene also controlled the rate of growth.

When injected into salmon eggs, the gene alters the way the fish's natural hormones work, allowing it to grow to market size in half the time of normal farm fish. That discovery was patented and now AquaBounty Technologies, of Waltham, Mass., could receive the FDA's go-ahead to start producing the transgenic fish, now using a gene from Chinook salmon and the antifreeze "promoter" from another cold-water fish, the ocean pout.

For genetic engineers, fish offer a number of advantages over most other animals. A spawning salmon produces thousands of eggs, which do not have to be carried by the mother. That greatly simplifies the task of implanting and cultivating fish in captivity.

So, when scientists implanted the antifreeze gene in Atlantic salmon back in the 1990s, they essentially created a new species. But the newly created fish is identical to normal salmon--with the exception of one gene out of approximately 40,000 that comprise the creature's DNA.

That single gene "allows the fish to reach market weight in half the time of traditional Atlantic salmon," says Dr. Ronald Stotish, the AquaBounty CEO.

That fast growth cuts the company's overhead costs by half, which gives them a huge economic advantage in a competitive market now dominated by Chilean and Norwegian salmon farms.

But the critics believe that the gene also creates a whole set of uncertainties and potential threats to human health or to the environment. Hauter, of Food & Water Watch, warns that the fish have not been adequately tested for allergies or toxicity.

She cites a recent study that claims transgenic salmon could have a greater effect on the environment. In particular, environmentalists warn that GM fish will inevitably escape into the open sea and compete with native fish.


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