BOB HIRSHON (host):
How raising salmon can kill salmon. I’m Bob Hirshon and this is Science Update.
A salmon farm can indirectly kill young wild salmon within a thirty-five mile radius. This according to a study of over fourteen thousand fish, led by Ph. D. student Martin Krkosek at the University of Alberta in Canada. He explains that salmon farms are teeming with sea lice: a surface parasite that’s relatively harmless to adult salmon, but deadly to juveniles.
MARTIN KRKOSEK (University of Alberta):
These fish are only about an inch long. They don’t have any protective scales, and all it takes is one or two lice to kill them.
In the wild, juveniles rarely get sea lice, because they grow up far away from adult carriers. But Krkosek found that fish farms along juvenile migration routes can infect and kill up to 95 percent of the young fish that pass by. As a result, he says that farming appears to be depleting the wild salmon population, rather than saving it.
I’m Bob Hirshon for AAAS, the science society.