Local officials concerned about invasive mussels

A potentially destructive invasive mussel larvae was detected October 2016 for the first time in Montana, and should the larvae spread, local officials said, it could cause major problems such as clogging the intake to the Havre water treatment plant.

"The city's pipe is 24 inches - they can clog that in a year," Hill County Commissioner Mark Peterson said.

Montana Fish, Wildlife and Parks says in a news release the mussel larvae, a freshwater mussel about the size of a fingernail, was detected in Tiber Reservoir in Liberty County, and "suspect" detections have turned up in Canyon Ferry Reservoir, the Missouri River below Toston Dam and the Milk River.

"This thing is a big issue," Peterson said. "If we can stop it now, it'll be beneficial."

Hill County Sanitarian Clay Vincent also said the earlier the better - and cheaper - to stop the spread, adding that a comparable example is other invasive biological species.

"You can compare the mussel to our invasive species in the weed department, the spotted knapweed, Canadian thistle, all of that. They just tend to take over," he said.

Keeping an eye out is one of the best things to do to keep it from spreading, Vincent said.

"People need to pay attention when they're bringing hay from different areas, boats from different streams or lakes, that they are not passing these things from one area to another. That's the way it gets around," Vincent said. "If you're going to be in one lake, you look at the motors, you look at the underside of the boats, make sure you're not bringing some of that stuff in."

The discovery of the mussels led to the creation of a Montana Mussel Response Team and to FWP creating the Aquatic Invasive Species Bureau which will be housed in FWP's Fisheries Division.

The department is proposing changing some regulations in response to what it is calling a natural resource emergency to manage the threat of invasive mussels spreading to other areas. A public hearing on proposed rule amendments is scheduled March 14 in Helena at FWP Headquarters, 1420 E. 6th Ave. The hearing will begin at 6 p.m.

See related story on Outdoors, Page B2.

Among the proposed amendments would be mandatory inspections of all out-of-state watercrafts prior to launching on any Montana waterbody; mandatory inspections of all watercraft traveling across the Continental Divide into the Columbia River Basin within Montana; mandatory inspections of all watercraft coming off Tiber and Canyon Ferry reservoirs including decontamination if necessary; drain plugs would be required to be removed, and if the watercraft doesn't have drain plugs, reasonable measures must be taken to dry or drain all compartments, including bilges; transporting lake and river water would be prohibited; live bait and fish would be required to be transported in clean domestic water where allowed in current fishing regulations. Upon leaving Tiber and Canyon Ferry reservoirs, bait and fish must be transported without water.