Researchers play matchmaker to save fish population

Biologists are using new genetic techniques to reduce inbreeding among salmon, but some scientists question if natural methods would have worked just as well.

The new technique involves a team of specialists who use egg trays and a rubber mallet to kill fertile fish and then mix their eggs with male milt, or sperm, and raise the resulting offspring in containers or pools. But over time, scientists have come to believe that salmon raised in this manner can be inbred and less resilient in the wild.

Now scientists are analyzing each salmon’s DNA before breeding them to make sure that the fish they match have no genetic relationship to each other. Previously, biologists picked the largest fish without knowing if they were related.

“We’re trying to mimic what’s going on in nature,” said John Carlos Garza, who runs the molecular ecology and genetic analysis team for the National Oceanic and Atmospheric Administration — or what he calls a “salmon mating service.”

While many scientists swear by Garza’s counsel, others question if the method is effective or necessary.

“Anytime you get tech solutions to natural problems,” said Peter Moyle, a professor emeritus of biology at the University of California, Davis, “it seems to me you wind up in trouble in the long run” (Matt Richtel, New York Times, Jan. 15). — SP