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Invasive Mussel Larvae Found In Four Colorado Reservoirs
Colorado Division of Wildlife press release
A Federal and State initiative to gather more information on the presence of aquatic invasive species in Colorado confirmed the presence of invasive mussel larvae in Grand Lake, Shadow Mountain and Willow Creek Reservoirs in Grand County. These waters are physically connected to Lake Granby. Quagga mussel larvae were discovered in Lake Granby earlier this summer.

Veligers, the larval stage of quagga and zebra mussels, were initially identified by a microscopic analysis of water samples and subsequently confirmed as invasive mussels by DNA testing. Results from an independent laboratory confirm that both zebra and quagga mussels are present in Grand Lake, while only quagga mussels have been found at Willow Creek, Shadow Mountain and Lake Granby.

The Colorado Division of Wildlife (DOW), Bureau of Reclamation, U.S. Forest Service (USFS) and the Northern Colorado Water Conservancy District are cooperating with local partners on the development of an appropriate plan for each of the Colorado-Big Thompson (CBT) reservoirs. Zebra and quagga mussels are closely related species that have similar biology, impacts and mechanisms for spread, which result in the same response practices.

Boaters from all CBT lakes are encouraged to participate in DOW’s special watercraft inspections and decontamination day on Saturday, September 27th. These inspections are designed to provide local homeowners and marina operators a convenient way to have their vessels checked for mussels or other invasive species. The inspections are scheduled from 9 a.m. to 12 p.m. at the East boat ramp at Grand Lake, and from 1 p.m. to 4 p.m. at the Sunset Point boat ramp on Lake Granby. Representatives from DOW, USFS and Reclamation will be on site to distribute educational materials and answer questions.

Monitoring also confirmed the presence of both zebra and quagga mussel veligers in Lake Pueblo. Zebra mussels were first identified last January. Sampling efforts were expanded this past summer to include 6 new sampling sites, which resulted in the find. Quagga and zebra mussels are known to coexist in many places in the eastern USA. State Parks has an inspection and decontamination program in place to prevent the spread of these mussels to new waters.

Public awareness and participation is the best weapon in the containment of invasive species. Invasive mussels endanger water quality and natural resources. Boaters are reminded to take the simple precaution of making sure that they Clean, Drain, and Dry their boat when they leave the lake. All boaters should remember to follow these steps to ensure they are not spreading the mussels to clean waters:

· DRAIN the water from the vessel, live well and the lower unit of the engine.

· CLEAN the hull of the vessel.

· DRY the vessel, fishing gear and other equipment.

· INSPECT all exposed surfaces.

· REMOVE all plant and animal material.

Zebra and quagga mussels spread from Eurasia to the Northeast and Great Lakes in contaminated ballast water of boats, on anchors and anchor lines. They quickly spread to the Mississippi River, its tributaries and inland lakes and have now established a presence in the Western States.

Zebra and quagga mussels are small barnacle-like mollusks with dark and light colored stripes. They smother aquatic organisms, such as crayfish and native clams and out compete native species for food and aquatic habitat. They damage equipment by attaching to boat motors or hard surfaces and clog water treatment facilities.

|For more information about zebra and quagga mussels visit