Amy Benson, USGS photo
LONG CREEK – A laboratory recently confirmed that a new foreign visitor – the European ear snail – has made its way into the John Day River system.
The North Fork John Day Watershed Council, announcing the find this month, said the snail was collected during regular monitoring work on the Middle Fork John Day River on Sept. 24.
Valeen Madden, the council’s project coordinator, found the snail in a drift net that had been set out near Bear Creek. Such nets are put in the current for six-hour periods to collect insects and crustaceans. The collected invertebrates are sent to a lab for identification and evaluation.
Rithron Laboratories of Missoula, Mont., provided positive identification of the snail.
Elaine Eisenbraun, executive director of the Long Creek-based watershed council, said the snail is an invasive species that has not been recorded in the John Day River system. Native to Europe and Asia, the snail gets its name from its ear-shaped shell.
Eisenbraun said the “invasive” tag means the snail, while exotic to North America, is increasing in population density on the continent.
However, it is not considered a “noxious” species, as it is not outcompeting or having any known detrimental impact on native species in the lakes and rivers where it is found.
The nearest prior discoveries of the snail were in Lake Billy Chinook, in Central Oregon, and Idaho’s Snake and Owyhee river drainages. In addition, significant populations have emerged in southwestern Oregon.
The Watershed Council will seek additional funding to search areas near the capture site to determine the level of prevalence of the population. Plans also call for the Oregon Department of Fish and Wildlife and Oregon Marine Board to look into ways the snail might have entered the basin.
“Rivers are such a dynamic element of our environment. It is important to keep an eye on the changes that take place naturally and as a result of human activity,” said Eisenbraun.
She credited the council monitoring staff for its “meticulous work” leading to the discovery of this change in the river system.
The council’s monitoring program, coordinated by Justin Rowell, is affiliated with the Intensively Monitored Watershed, a working group supported by the Oregon Watershed Enhancement Board,NOAA Fisheries and other funders. That work draws participants from universities, agencies, and nonprofits who are collecting information about the health of the Middle Fork and its response to restoration activities.