Hundreds of thousands of young salmon have died in “a large mortality” event after being released into a California river, state officials reported Saturday.
The California Department of Fish and Wildlife (CDFW) released approximately 830,000 baby Chinook salmon into Fall Creek, a tributary of the Klamath River, on February 26 to restore the species to the area.
Soon after the agency’s first fish release from its new hatchery in Siskiyou County, officials said the salmon likely died of a “gas bubble disease” that may have occurred as the group migrated through the Iron Gate Dam tunnel, “old infrastructure that is targeted for removal.”
The $35 million Fall Creek Fish Hatchery’s mission to repopulate the river has been set back by the mysterious disease, caused by “an increase in the dissolved gas pressure above the ambient air pressure” according to the National Library of Medicine.
“Fish, especially fry, with the chronic form die slowly without symptoms,” the findings state, explaining how acute cases come with mental and physical symptoms before death.
The state’s wildlife department assured the public that “there is no indication the mortality is associated with other Klamath River water quality conditions” and said that other fish that came downstream of the dam appeared to be “healthy.”
“The problems associated with the Iron Gate Dam tunnel are temporary and yet another sad reminder of how the Klamath River dams have harmed salmon runs for generations,” the agency added. “CDFW will plan all future salmon releases below Iron Gate Dam until this infrastructure is removed.”
Democrat Gov. Gavin Newsom previously backed the “controversial proposal to remove four Klamath River hydroelectric dams,” the Post Millennial’s Katie Daviscourt reported. “Now, the same fish he swore to protect could be killed in the process.”