Fish farming could drive some species of wild salmon to extinction, a new study says. Canadian researchers found a direct connection between the growth of such farms in British Columbia and a sharp drop in wild salmon nearby, the Washington Post reports. They attribute the problem to deadly sea lice that thrives in the farms, then spreads to wild salmon that swim by the netted cage.
"The wild population is dropping so fast that there isn't much time left to act," the study's lead author said. Sea lice breed by the billion in open-sea farms, then attack vulnerable young wild salmon migrating to rivers. The study, published in Science, found rivers normally full of salmon to be empty, with starving bears on their banks.