LAKE OROVILLE -- Winter flooding and copious spring snowmelt have brought frightening-looking creatures to Northern California waterways in a sight one observer called “the stuff nightmares are made of.”
They’re Pacific lampreys, a parasitic type of primitive fish, resembling eels, that latch onto to their prey with a round, sucker-like mouth. They're native to state waterways, but they aren't typically seen near Lake Oroville.
But they've showed up en masse at a state fish hatchery on the Feather River near the Oroville Dam, which was severely damaged in the wet winter. On Tuesday, dozens of lamprey could be seen – squiggling like tentacles – in the hatchery's viewing windows that allow visitors to watch salmon and steelhead ascend to their spawning grounds.
“Creepy, but so cool!” the Lake Oroville Visitors Center said in posting video of the lampreys on its Facebook page.
Tour guide Jana Frazier, who works for the California Department of Water Resources, took the video this week. The water is so high at the fish ladder that the lamprey are able to ascend, going into locations where they're not normally seen.
“This was literally the perfect storm,” she said of the conditions.
With their teeth-filled sucker mouths, the fish are scary-looking, but they're harmless to humans, Frazier said.
"You've got nothing to worry about if you go wading or swimming in the river," she told television station KCRC in Redding.
Lamprey are native to fresh waters of California, having a life cycle similar to salmon. Juveniles live in state rivers for several years, then head out to the Pacific Ocean to mature, attaching to host fish and feeding off them. They return to the rivers in spring, swimming upstream to spawn and then die.
The Feather River Fish Hatchery was built by the state to replace salmon and steelhead spawning areas that were lost when the dam was completed in 1967.
Frazier said she saw one steelhead take a look at lamprey and "split," swimming rapidly away.