Jackson County: New Zealand mud snails found in South Delaney Butte Reservoir

A picture named newzealandmudsnail

From the Summit County Voice (Bob Berwyn):

Wildlife experts discovered the mudsnails during a shoreline survey at the end of July. This is the fourth location where the invasive freshwater mollusks have been detected in Colorado.
“The New Zealand mudsnail competes with our native invertebrate species,” said Elizabeth Brown, the division’s invasive species coordinator. “So far, we haven’t seen huge impacts to our fisheries. But New Zealand mudsnails have the potential to seriously disrupt the aquatic communities that are the foundation of the food web. If mudsnails become numerous enough, they can reduce the availability of nutrients to their point where it harms fish populations.”

Native to New Zealand, New Zealand mudsnails were first detected in the United States in 1987 in Idaho’s Snake River. Since then, the species has spread rapidly throughout the West, infesting waters in Arizona, California, Colorado, Idaho, Montana, Nevada, Oregon, Utah, Washington, Wyoming and British Columbia.

State wildlife officials first discovered New Zealand mudsnails in South Boulder Creek in 2004. Subsequently, the DOW has confirmed infestations in the South Platte River between Eleven Mile and Spinney Mountain reservoirs and in the Green River near the Colorado/Utah border…

A major reason for DOW’s concern is the snail’s astounding reproductive capacity. New Zealand mudsnails reproduce asexually and the release of one snail can create a population with a density of between 100,000 to 700,000 snails per square meter. New Zealand mudsnails have no natural predators in outside their native range. Scientists have not yet found a way to contain or eliminate mudsnail infestations.
“Our primary goal at this point is to keep them from spreading, and for that we need anglers and boaters to take common-sense steps to prevent the transport of mudsnails to other locations,” said Brown.

The primary vector for spreading New Zealand mudsnails is human-assisted transport overland, on waders, fishing gear and boats. Unlike zebra and quagga mussels, New Zealand mudsnails cannot attach to hard surfaces. Instead, they “hitchhike” or hide in mud or plant materials embedded on dirty boats and fishing equipment. The mudsnails–only 1/8 inch in length when fully mature–can live out of water for days in mud or other moist environments…

For more information about New Zealand mudsnails and how to prevent their spread, please visit this link.

More invasive species coverage here.

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