Saturday, June 26, 2010

Is it time to become a Luddite?

Fish. Today I'm thinking about fish and becoming a Luddite.

See if you might join me...

Genetically engineered farm-raised salmon. The engineer in me says "so what?" But the scientist in me is bothered by what they have engineered, rather than the mere fact of engineering itself.

They're making the salmon grow faster by switching a gene that normally slows down a salmon's feeding rate in cold water. We know that some fraction of these fish will escape from fish farms and some fraction of that fraction will survive to mate with wild salmon. Even if they "sterilize" the salmon, there will be some small fraction where the sterilization fails (failure is a statistically predictable occurrence in any industrial process). We know it's not a matter of "if" but "when" such engineered fish will mate with wild salmon

What we don't know is the effect on wild salmon populations.

I will be the first to admit that it is likely that this mutation would not survive in the long run; otherwise evolution would not have already selected for fish with a gene that reduces growth in cold water. But the evolutionary long run is measured in thousands or tens of thousands of generations. Since a salmon lives between 1 to 8 years from birth to spawning death, we don't know what evolution will do before the long run.

Here's a possible scenario: a few fish escape and breed with wild salmon, providing a new generation of which some fraction have the switched gene. These fish grow faster than the wild salmon and outcompete the wild salmon for mating, increasing their presence in the gene pool. This continues for some time with no noticeable effect on salmon populations. Eventually, the majority of the wild population carries the new gene and grow faster. Then the next environmental crisis arises and the salmon food sources are reduced. The wild salmon with the switch gene cannot get enough food because their hunger doesn't go dormant. The wild salmon population crashes. The only salmon surviving the crisis are those with the original gene; but they are a depleted population and may take centuries to come back. Or they may simply go extinct.

I wish they'd stick to genetically engineering cows, pigs and chickens. We've been genetically engineering these through selective breeding for the last 7000 or 8000 years, so all we're doing is switching our engineering tools. There's not much worry about cows, pigs and chickens escaping and causing problems in wild populations. And if they screw up cows, pigs and chickens, we can simply choose not to eat them.

This whole effort is another case of privatization of profit and socialization of loss. Do you think that the salmon farms will carry enough insurance to compensate the fisherman if the wild population crashes? It will be another, "Oops, sorry about that. I'm sure you don't mind picking up the tab Mr. and Ms. Taxpayer."

No comments: