The invasive northern crayfish was first reported in Oregon last month, in an Ashland waterway that eventually empties into the Rogue River.
Native to the Midwest, they can outcompete local crayfish species and prey on endangered salmon and rainbow trout eggs.
Rick Boatner of the Oregon Department of Fish and Wildlife said his team conducted a survey last week to determine the extent of the damage.
“You know, I was disappointed,” says Boatner. “I was hoping they were still right in the Ashland area, but they’re outside of the Ashland area – in Bear Creek, which is part of this system. So they’re heading towards the Rogue.
Boatner says there’s not much to do now to contain the crayfish, but encourages people to report northern crayfish sightings to track their range.
“So maybe we’re at a point where we can’t do much,” he says. “Since they are everywhere.”
Boatner says control methods such as poison or trapping would either be ineffective or harmful to native species at this point.
It is still unclear how crayfish were introduced to the area. Boatner thinks the remains of a school science project might have been dumped in a nearby waterway; unaware that crayfish are invasive.
Importing non-native crayfish into Oregon requires a permit, and violators may be subject to penalties or civil fines.