GRAND JUNCTION, CO — In a decisive move aimed at the preservation of Highline Lake State Park’s aquatic ecosystem, Colorado Parks and Wildlife (CPW) has unveiled a new strategy to eradicate zebra mussels. The invasive species, notorious for reproducing rapidly and severely disrupting native habitats, was found in the lake on October 1 during a routine buoy removal.
Invasive Species Program Manager Robert Walters emphasized the careful thought process behind the updated plan, stating, “We did not make this decision lightly or in haste.” He noted that the new action plan is the result of extensive conversations involving multiple departments within CPW.
This newly devised plan will be rolled out in phases. The initial stage, scheduled for late 2023, will involve treating the lake with a higher concentration of EarthTec QZ, an EPA-registered copper-based molluscicide. It is the same chemical used earlier this year but failed to achieve complete eradication. The objective is to control the zebra mussel population and severely limit its reproductive capabilities in 2024.
Walters explained the urgency, saying, “A single female zebra mussel can produce more than 30,000 eggs per reproductive cycle. Any mussel we can prevent from reproducing increases the probability of our success next fall.”
As a more drastic measure, the second phase will begin in early 2024 with a gradual emptying of Highline Lake, expected to be complete by the year’s end. This action comes with significant repercussions for outdoor recreation. Highline Lake will be closed to all motorized boating for the entire 2024 season.
Highline Lake State Park Manager Alan Martinez addressed the inconvenience this will cause, saying, “We understand this isn’t ideal for our boating and angling community. But we hope people recognize the severity of this issue and take personal responsibility for preventing future occurrences.”
One of the unfortunate fallouts of the plan is the impossibility of transferring fish from Highline Lake to other bodies of water, due to the risk of also transferring viable mussels. Therefore, CPW is implementing an emergency fish salvage, effective October 9, removing all bag and possession limits for the reservoir. Anglers are encouraged to catch as many fish as possible using lawful methods, although all fish must be dead prior to transport.
“Eradication of zebra mussels has been, and will continue to be, our goal at Highline Lake,” assured Ben Felt, Northwest Region Senior Aquatic Biologist. “CPW is committed to rebuilding the Highline Lake fishery once the eradication project is complete.”
As the state makes strides to tackle this environmental issue, individuals can play their part in preventing similar future incidents by adhering to Leave No Trace principles. The most immediate way to help is by cleaning, draining, and drying boats and equipment that come in contact with water bodies. Through collective action and public responsibility, the hope is to safeguard Colorado’s cherished natural resources for generations to come.