Salmon Transport

摘要

At the turn of the 19th century, up to 16 million salmon and steelhead trout migrated up the waterways of the Columbia River Basin to spawn. Today, about one million salmon and an equal number of steelhead return, in large part because the rivers have been dammed. When fish swim from their hatching grounds to the ocean, they learn the route and return by the same course years later. If a dam blocks it, the run discontinues. To aid migration on the Deschutes River in Oregon, engineers working for Portland General Electric developed a facility to separate juvenile fish from adults. Since the $lO8-million facility began operating in December 2009, biologists there have sorted 600,000 fish to find the juveniles and transport them downstream by truck. Last year, scientists recorded the first fish to return to the river to spawn, an event that hadn't happened in 40 years.