06/25/2026
As we enjoy our Oregon water this summer, please be aware of potential invasive species.
A single dead adult quagga mussel was found out of water on the shoreline at Prineville Reservoir on June 6 during a routine survey for aquatic invasive species. This marks the first time that this highly invasive freshwater mussel species has been found in or near an Oregon waterbody.
Only the single quagga mussel was found. Additional intensive surveys by Portland State University (PSU) Center for Lakes and Reservoirs did not find any other mussels along the shoreline at Prineville Reservoir. Test results from water samples and environmental DNA (eDNA) tests by PSU that came back late last week also showed no sign of invasive mussels. It is unknown at this time how the quagga mussel ended up on the shore of the reservoir.
Recreational boats are known to be a major source of freshwater invasive mussel spread in the United States. Inspections have intercepted boats fouled by live invasive mussels prior to launching in Northwest waters a number of times in recent years.
Boaters are also reminded that they are required to stop at check stations for inspection. Check stations are currently located in Brookings, Ashland, Klamath Falls, Ontario and Umatilla. A roving check station will also be at boat ramps around Prineville Reservoir and central Oregon periodically in coming weeks to inspect watercraft for invasives.
To prevent potential dispersal of freshwater invasive mussels, boaters should: CLEAN all boats, trailers, and other equipment after leaving a lake or stream. DRAIN all water from vessels and allow them to DRY before launching into another waterbody.
More information is available below.
