CASPER, Wyo. — Montana Fish, Wildlife and Parks is recommending that the 60 acre Lake Elmo in the Billings Heights area be drained next year in order to eradicate invasive clams.
“Asian clams were found in Lake Elmo in 2019 by FWP employees training to search lakes for aquatic invasive species,” Montana FWP said on Tuesday, Oct. 20. “Subsequent searches of an irrigation storage reservoir and ditches and rivers upstream and downstream from the lake found no other Asian clams, suggesting that they are limited to Lake Elmo. The invasive clams are found nowhere else in Montana.”
“Asian clams can clog irrigation and other water system infrastructure, filter and remove important food sources needed by other species and promote the growth of bacteria and algae. Their shells are sharp, causing a safety hazard for people using the lake.”
Dealing with invasive aquatic species is something that occurs in Wyoming as well. The Wyoming Game and Fish Department reported in Aug. that technicians had intercepted multiple watercraft transporting invasive species.
Montana FWP said that public comments received in March 2020 “indicated strong support for FWP to address the presence of Asian clams in Lake Elmo and take the opportunity to improve fish habitat, access and park amenities.”
Montana FWP says that scientific evidence shows that the best way to kill Asian clams is by drying and freezing.
“FWP biologists believe that draining the lake to expose all Asian clams to winter weather provides the best opportunity to eradicate them,” the release adds. “This fall the lake level already has been drawn down by two to three feet to try to kill Asian clams in shallow water near the shore.”
“Most of the clams found to date in the lake have been in less than six feet of water. Lake Elmo State Park and the remaining water will remain available to the public during this winter’s partial drawdown. The lake will refill in April 2021.”
If the lake is drained next year, Montana FWP says they recommend that other improvements to fish habitat be conducted and that park amenities should be added which “would be more difficult and expensive if the lake was full of water.”
“Projects could include excavation to deepen the lake, handicap-accessible rock jetties, sunken structures for fish, a boardwalk between the lake shoreline and Lake Elmo Drive, fishing nodes along the boardwalk, work on the dog park shoreline and a sediment retention area,” Montana FWP adds. “All projects would depend on funding and completion of engineering and planning.”
Montana FWP fisheries biologists and managers have finished a draft environmental assessment on their plans to eradicate the invasive clams and improve the area.
“People are encouraged to comment on the draft environmental assessment and its recommendations by Nov. 18, 2020,” Montana FWP says. “The environmental assessment recommends that FWP drain the lake completely starting in the fall of 2021, leave it dry for the winter, then refill it in April 2022.”
“The draft environmental assessment discusses the process of draining the lake, precautions to keep Asian Clams from spreading during draining, disposition of fish and aquatic species now in the water, repopulating fish in the lake in 2022 and effects of the various projects.”
The assessment is available online.
“Comments are due by Nov. 18, 2020,” the release reiterates. “Phone questions may be directed to Mike Ruggles, FWP’s regional fisheries program manager, at 406-247-2961 during normal business hours. Comments may be emailed to fwpregion5pc@mt.gov or mailed to:
- Mike Ruggles
- Montana Fish Wildlife and Parks
- 2300 Lake Elmo Drive
- Billings, MT 59105
