DENVER (KDVR) — Colorado Parks and Wildlife is working hard to eradicate a species of mussels native to Eastern Europe that’s currently making itself at home in Highline Lake.
Zebra mussels are an invasive species that have spread to 33 U.S. states after being introduced to the Great Lakes through discharged ballast water of ocean-going ships, according to CPW. Currently, only Highline Lake in Colorado has zebra mussels, and CPW wants to stop the spread.
To further this goal, CPW will apply EarthTec QZ, an EPA-registered copper-based molluscicide, to the lake. This is the same copper-based molluscicide applied to the lake in March.
Because of the potential for accumulation of copper in the edible portions of fish, effective Fri. Nov. 3, CPW will end the emergency salvage regulation that went into effect on Oct. 9. Also effective Nov. 3, fishing will be prohibited on Highline Lake.
The emergency fishing closure was approved by CPW Director Jeff Davis and only affects Highline Lake. All existing regulations on Mack Mesa, Mack Wash, and surrounding bodies of water remain in effect.
Zebra mussels cause ecological damage to areas they invade by filtering out algae needed to feed native species and incapacitating native mussels, according to the U.S. Geological Survey. The species can also cause issues for water infrastructure, such as power plants.
Any waterfowl hunters planning to hunt using blinds at Highline Lake are advised to leave their dogs at home. Since CPW is applying EarthTec, dogs should not enter or drink the water until further notice.
Zebra mussel eradication plans restarted Oct. 1
The renewed efforts to eradicate zebra mussels in Highline Lake were in response to five adult mussels found in the lake while removing buoys on Oct. 1. This was the second time CPW found adult zebra mussels in Highline Lake.
“We did not make this decision lightly or in haste,” said invasive species program manager Robert Walters in a release. “Over the past year we have had numerous discussions with CPW’s Northwest Region aquatic, regional, and state park staff, and we have come up with a plan that builds upon that work that was performed last spring.”
A second phase of the eradication plan will occur in 2024. Near the beginning of the year, CPW will begin to lower Highline Lake in anticipation of completely emptying the lake by the end of 2024.
This means all motorized boating on the lake will not be allowed in 2024.
CPW said in an Oct. 1 release that the fish in Highline Lake will not be moved due to a risk of moving viable mussels both inside or on any fish. To this end, bag and possession limits were reduced for anglers.
The emergency fish salvage was established Oct. 9 and all anglers were allowed to keep all fish they caught from the shoreline. All fish removed from the lake must be dead before leaving the lake area, and the emergency salvage ends Nov. 3.