Single invasive quagga mussel found at Prineville Reservoir; wider survey turns up negative
By Griffin Beach on Wednesday, June 24th, 2026 in More Top Stories Northeastern Oregon News
PRINEVILLE — Crews from Portland State University’s Center for Lakes and Reservoirs discovered a single dead adult quagga mussel on the shoreline of Prineville Reservoir, but an extensive survey showed it was the only example of the invasive species at the reservoir.
It is unknown how the mussel ended up on the shore of Prineville Reservoir. Quagga mussels are small non-native freshwater mollusks that caused issues in the United States since they were introduced in the 1980’s. They are known to reproduce quickly and can clog water intake systems, outcompete native species, and disrupt recreation along with aquatic habitats and infrastructure.
Since the mussel was found on June 6 federal, state, and local agencies have worked together under the Oregon Invasive Freshwater Mussel Rapid Response Plan. They have worked to coordinate continued surveillance and sampling, along with outreach efforts to boaters around the state.
“We are taking this finding extremely seriously, but also cautiously as we work to confirm what we’re seeing at Prineville Reservoir. said Keith DeHart, Oregon Department of Fish and Wildlife aquatic invasive species coordinator. “We are coordinating closely with our state, federal, tribal, and local partners, and preparing to move quickly based on the evidence we find.”
Surveys by the crews from PSU completed six dock inspections and 22 shorelines. They also performed 57 mussel larva tows filtering more than 296,000 liters of water. They said all results from the water samples were negative for quagga mussels.
Monitoring teams will continue routine intensive sampling efforts moving forward to ensure early detection and subsequent rapid response if quagga mussels are present.
Officials remind boaters to clean all boats, trailers, and associated equipment after leaving a lake or stream, and to drain all water from vessels and allow them to dry before entering another body of water.
