The debris flows also caused massive fish die-offs in the Klamath River. A remote monitoring system managed by the Karuk Native American tribe recorded the oxygen saturation level in the Klamath River near Seiad Creek ( downstream of the debris flows) plunging to 0% for several hours on the night of August 3 and again on August 4. This caused the death of what may have been tens of thousands of fish along a of the Klamath River. The species affected included suckers, juvenile salmon, lamprey eels, crayfish, and steelhead trout. The Karuk and Yurok Native American tribes have been working for years to protect fragile salmon populations in the Klamath River, which may be further impacted as a result of the fire's aftereffects.
