Hundreds of thousands of salmon dead from ‘gas bubble disease’ in US river

Mass die-off in Klamath River caused by extreme changes in water pressure amid largest dam removal project in US history

As many as hundreds of thousands of newly hatched Chinook salmon released into the Klamath River have died due to gas bubble disease" caused by extreme changes in water pressure.

The young salmon fry were released amid the largest dam removal project in US history along the 257-mile-long river, which flows across Oregon and California. Four hydropower dams are being removed, reconnecting the lower and upper portions of the Klamath River for the first time in a century and allowing fish free passage along the river.