An outbreak of a parasitic disease in small parts of the Klamath River could reach dangerous levels as it continues to infect more salmon, the Yurok Tribe announced on Friday.

Ichthyophthirius multifillis — also known simply as “ich” — has been found in fish near the mouth of Blue Creek on the Yurok Reservation. This is the third time ich was detected on fish in the Klamath River since the 2002 outbreak, which led to the deaths of 35,000 adult Chinook salmon and steelhead fish along the Klamath.

Low levels of ich were found last year in the Klamath River, but they were not significant enough to spark concern. This year, ich is back and it could be devastating. Yurok Tribal Chairman Thomas P. O’Rourke said the Yurok Tribe will do anything possible to avoid another huge outbreak.

“We take this threat to our fish very seriously, and we’re looking at every option to protect our fish. We don’t want to go through another catastrophe like the fish kill in 2002,” O’Rourke said.

Warmer temperatures throughout the summer and the continuing California drought, which is going on five years, also contributed to the spread of the pathogen.

According to Michael Belchik, senior fisheries biologist for the Yurok Tribal Fisheries Program, a small number of adult salmon migrated upriver in extremely warm water temperatures and then, because of portions of the river drying up, became stuck in a relatively small thermal refuge where the disease had the opportunity to spread.

He also concluded that lower temperatures and increased water flow reduces the ability of diseased organisms to find and infect other fish.

“Well, it’s definitely not good news,” Belchik said, “Right now we’re trying to figure out the geographic extent of the outbreak.”

The infected fish were found near the mouth of Blue Creek, which is located on the Yurok Reservation about 15 miles from the Klamath River.

Whether or not the disease has spread to more than just the Klamath River is still under investigation as federal, state and tribal co-managers continue to test and sample fish in various parts of the region.

“We’ve sent out crews that are (conducting) additional sampling of the fish,” Belchik said, “and we’re working with (our) co-managers to figure out what our next step will be.”

Natalya Estrada can be reached at 707-441-0510