California Fire and Floods Turn a River to ‘Sludge,’ Killing Thousands of Fish

As a deadly fire continued to burn last week in the Klamath National Forest in Northern California, Kenneth Brink, a local fisherman, counted dead fish in a river that had turned to the consistency of “chocolate milk.”

Mr. Brink, 45, a member of the Karuk Tribe, lives in Happy Camp, a town of less than 900 people on the Klamath River, in Siskiyou County, Calif. The town is near the border with Oregon. On Friday, he drove about 20 miles upstream, where he made the grim discovery: thousands of dead suckerfish, salmon and trout, many floating belly up.

“It smells vile,” Mr. Brink said. “If it was in that river, it died.”

The McKinney fire began on July 29 and has exploded to more than 60,000 acres, killing four people and becoming California’s largest fire so far this year. According to local tribal leaders, the fire has also led to the mass fish kill in the Klamath River, which runs for more than 250 miles from southern Oregon, through Northern California and out to the Pacific Ocean.

Up to three inches of rain fell on areas burned by the fire on Tuesday, sending a debris flow of burned soil, rocks and downed timber into the river, said Mike Lindbery, a public information officer for the McKinney fire.

That debris turned into a plume of brown “sludge” that made its way downriver, according to tribal representatives. A water quality monitoring station on the river recorded the dissolved oxygen level in the water at zero for both Wednesday and Thursday, they added. Sea creatures usually survive in water that has about eight milligrams of oxygen per liter, but the oxygen level in that section of the river made it impossible for the fish to survive.

“It’s just sterilizing the entire river in that reach,” said Craig Tucker, a policy adviser for the tribe. Whether the debris flow would affect the Chinook salmon’s migration, which usually begins in the fall, was not known, he added.

On Sunday, the McKinney fire, which has prompted evacuations for thousands of people, was 40 percent contained, authorities said in a report on the fire. But Mr. Lindbery, the public information officer, cautioned that dangerous conditions in the coming days could reverse some of that progress.

Gusty winds, low humidity and a “very unstable atmosphere” over the fire, he said, could create circumstances whereby embers might fall well outside the fire line. There was also a possibility that a huge cloud known as a pyrocumulonimbus could develop and ultimately collapse, generating erratic winds, he said.

Development and dam building had already threatened the salmon population of the Klamath River, impacting local tribal groups.

Mr. Brink, the fisherman, noted that all of the fish that were killed hold cultural importance for the local tribes that live near the river. He said that he felt frustration over the region’s history of forest management, which had in the past prohibited local tribes from conducting cultural burns to tame the landscape.

“It’s chaos,” he said of the impact of the fire on his community of Happy Camp, which is within about 35 miles of two blazes: the deadly McKinney fire and the Yeti fire, which has grown to nearly 8,000 acres.

He added, “I’m about ready to cry.”