A historic California species is in imminent danger of extinction. A huge effort just launched to save it

On a remote stretch of creek in California’s far north, a team of biologists dropped fishing nets into a cold pool of water Tuesday with high hopes: to save one of the state’s great salmon runs by bringing the fish into captivity. State and federal scientists, which began catching fish across the Sacramento River basin last week, believe the number of salmon that migrate to the region in spring has gotten so low that they need to take the extraordinary step of establishing a captive stock for safe keeping.