Massive Chinook Salmon Fry Die-Off Reported on the Klamath River

In a disheartening turn for salmon restoration efforts, the California Department of Fish and Wildlife (CDFW) reported a significant loss of newly released fall-run Chinook salmon fry in the Klamath River, attributed to gas bubble disease. This unfortunate incident occurred after the CDFW’s first release of approximately 830,000 salmon fry from the new Fall Creek Fish Hatchery in Siskiyou County on February 26.

These fry were released into Fall Creek, a tributary of the Klamath River, with high hopes as part of California’s ambitious $35 million initiative to restore Chinook and coho salmon populations along the undammed portions of the river. However, as these young salmon made their journey through the Iron Gate Dam tunnel, they encountered conditions leading to gas bubble disease—a fatal condition often resulting from rapid pressure changes.

Monitoring downstream revealed the mass mortality, pointing to the outdated Iron Gate Dam infrastructure as a significant factor. Notably, the water quality in the Klamath River, including turbidity and dissolved oxygen levels, appeared stable and suitable for salmon health, ruling out other potential causes for the die-off.

This incident underscores the detrimental impact of the Klamath River dams on salmon populations, a problem that has persisted for generations. In response, the CDFW has decided to conduct all future salmon releases below the Iron Gate Dam until the dam and its problematic tunnel are removed.

Despite this setback, the Fall Creek Fish Hatchery still houses over 3 million healthy fall-run Chinook salmon, with plans for additional releases later this month. The hatchery aims to raise and release 3.25 million fall-run Chinook annually, and the current stock exceeds this goal, providing a buffer to compensate for the recent losses.