Mussel DNA, but no larvae or adults, found in Tiber

Samples taken last year from Tiber Reservoir bolstered older evidence for the presence of invasive mussels.

In a press release Thursday, Montana Fish, Wildlife and Parks announced that samples of environmental DNA (eDNA) taken by it and the U.S. Geological Survey during 2017 indicated invasive mussels’ presence in Tiber Reservoir.

In Fall 2016, the discovery of quagga mussel larvae and a shell fragment there triggered a massive effort to detect and contain the animals. Over the course of 2017, the press release states, “FWP and partner agencies collected more than 1,500 plankton samples from 240 waterbodies,” including 128 plankton tow samples from Tiber and 147 at Canyon Ferry, where their presence is suspected.

Through these tests, “no adult mussels or larvae were found.”

While mussel eDNA was found through separate tests in Tiber, the state cautions that this evidence is “not conclusive” about their presence, and says it plans to form a scientific advisory panel to guide eDNA’s use in mussel detection.

In 2018, Fish, Wildlife and Parks says it will maintain inspection and decontamination requirements for all boats exiting the Tiber and Canyon Ferry reservoirs, and continue mandating inspections for all watercraft entering the state and crossing the Continental Divide.

For more information on these requirements and the state’s response, visit, http://musselresponse.mt.gov/.

Reporter Patrick Reilly can be reached at preilly@dailyinterlake.com, or at 758-4407.