State officials will survey areas of the canal from Emigrant Lake to Lithia Park
By Lee Juillerat for Ashland.news
Northern crayfish, which can negatively impact other fish population, were found in the Ashland canal, according to the Oregon Department of Fish and Wildlife.
The finding is the first documented existence of the northern crayfish, a non-native species, in Oregon. ODFW spokesmen said the species is native to the Midwest and said invasive populations exist in California and Washington.
“This discovery could be bad news for Oregon’s native signal crayfish — northern crayfish are much more aggressive,” Rick Boatner, ODFW’s invasive species coordinator said in a news release. “And, as omnivores, they can prey on signal crayfish, the eggs of salmon and steelhead, and consume native vegetation.”
Because Ashland Canal leads to Bear Creek and the Rogue River, Boatner said Northern crayfish have the potential to duplicate what rusty crawfish did in the John Day River Basin. Forty-two years ago, it’s believed rusty crayfish were released in the John Day River near Mitchell by a school group. The crayfish have since taken over most of the river from native signal crayfish and are predicted to enter the Columbia River by 2025. Signal crayfish are now displaced and rarely seen today.
Although the Ashland Canal can have low stormwater levels, crayfish can burrow in mud and wait for higher water. They can also travel over land to other water bodies.
Boatner said he and his team will begin surveying selected areas of the canal starting above Emigrant Reservoir to Lithia Park and trapping any northern crayfish found. If the species is established, Boatner says they are most likely here to stay and will continue to spread in the Rogue River basin.
Anyone with information of a crayfish release in the Ashland area is asked to contact Boatner at 503-947-6308. Reports of invasive fish and wildlife can be made online at oregoninvasiveshotline.org.
Schools are reminded that classroom specimens cannot be released into the wild; a permit is required to import non-native crayfish into Oregon. Aquarium fish and other pets are also not allowed to be released. These actions can cause significant harm to Oregon’s native fish and wildlife species.
Crayfish have also been a problem near Crater Lake National Park, where they have seen a rapidly growing population along shorelines in the caldera. The crayfish have an acquired taste for the Mazama newt, an endemic species found only at the park.
Recent studies done at Crater Lake have indicated there is no way to eradicate the crayfish, which are regarded as resilient and have been found deep in the lake. Crater Lake officials previously said the invasive species found there “will likely result in the fallout of the native Mazama newt populations of the lake. Our researchers are continually monitoring their populations and are considering possible solutions.”
Email freelance writer Lee Juillerat at firstname.lastname@example.org.