Fishy Discovery: Staggering Amount of 830,000 Young Salmon Released in California River Found Dead

Shortly after the release of approximately 830,000 fall-run Chinook salmon into the Klamath River by California wildlife officials, a staggering number of them were discovered dead.

Officials from the California Department of Fish and Wildlife (CDFW) suspect that the unusual mass deaths are attributed to gas bubble disease.

These salmon were introduced into the river near the California-Oregon border following the historic removal of the dam in November. The initiative aimed to restore the river's natural flow, enhancing the habitat crucial for the protected species.

Based on downstream monitoring data, it appears that the salmon fry experienced significant mortality.

CDFW officials stated in a news release that the likely cause of death is gas bubble disease, possibly occurring as the fry migrated through the Iron Gate Dam tunnel — a structure slated for removal along with the dam itself later in the year.

Gas bubble disease arises from environmental or physical trauma, often linked to drastic pressure changes. However, CDFW emphasized that there's no evidence linking the fish deaths to water quality issues in the Klamath River.

The fish were released recently, following normal oxygen level readings in the river. Monitoring equipment indicated the presence of healthy yearling coho and Chinook salmon downstream of the dam.

These fish were bred at the state-of-the-art Fall Creek Fish Hatchery, a $35 million project aimed at supporting and restoring Chinook and coho salmon runs on the undammed Klamath River.

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Acknowledging the temporary challenges posed by the Iron Gate Dam tunnel, CDFW stated that future salmon releases will be planned below the dam until its removal. The detrimental impact of the dams on salmon runs underscores the urgency of their removal.

Despite the losses in the river, the Fall Creek Fish Hatchery still houses around 3.27 million healthy fall-run Chinook salmon. Further releases are scheduled for later this month to meet the annual production goal of 3.25 million fish.