Major Salmonid Mortality Feared Due to Gas-bubble Disease in Connection With Klamath Dam Removal
https://www.theguardian.com/environment/2024/mar/05/salmon-klamath-river-dam-removal-project
It seems incredible to me that this release seems to have been done with seemingly little anticipation of this outcome. Perhaps with millions more fry still to be released, this might have been considered a ghastly, morbid experiment.
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.
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Last week, the California department of fish and wildlife (CDFW) released 830,000 hatchery-raised fall-run Chinook, only to discover days later that they were dying downstream of the 173ft Iron Gate dam, which is scheduled to be demolished soon. A tunnel at the dams base had been opened to allow the river to pass freely across it for the first time in a century, a step before the structure could be fully removed.
Many of the young fish, which were only 1-2in long, appear to have died passing through that tunnel, because the water pressure inside was too great for them. Officials do not know exactly how many of the fry have died, but expect a very high mortality rate, according to Jordan Traverso, deputy director of communications for the CDFW.