Great Lakes Article:

Dangerous zebra mussel migrates its way to West
By Launce Rake
Las Vegas Sun
Published January 12th, 2007

LAS VEGAS – Twenty years ago, the tiny zebra mussel was unknown in North America. But somewhere the tenacious invader hitched a ride on a boat from Europe and settled in the Great Lakes.

Within a decade, zebra mussels were fouling the water intakes for nuclear power plants, ruining pleasure boats and wiping out freshwater ecologies throughout the Eastern United States and Canada. Federal, state and local agencies worked unsuccessfully to contain the invasion to the Great Lakes, then to the Mississippi River and its tributaries.

Until last Friday, the invader hadn’t been seen west of the Continental Divide. Now it’s been found in Las Vegas’ back yard.

The zebra mussel or a close relative – scientists are working on a final identification – has been found in Lake Mead. The discovery has officials from federal, state and local agencies reeling, attempting to ascertain the level of threat to their operations – and the future of Lake Mead as a fish habitat.

“This is almost heartbreaking news that the mussels are here,” said Kent Turner, resource management chief for the National Park Service’s Lake Mead National Recreation Area. The implications of the discovery are huge not just for the lake, but for all the downstream users on the Colorado River, because the larva from the mussel can float freely in the water.

Other Western states, too, could face the invasion as the mussel travels with boats from lake to lake.

Any boat that uses Lake Mead – the most popular in the West – could advance the invasion, just as a boat was probably responsible for bringing the animal into Lake Mead.

Officials of Western states are scheduled to meet Jan. 31 in Las Vegas to discuss the threat. The discovery three weeks before the meeting of the 100th Meridian Initiative, the unsuccessful cross-agency effort to contain the mussel, brings new urgency to the gathering, he said.

Although the mussel is just an inch long, densities as high as 700,000 per square yard have been found at water intakes on the Great Lakes, according to the U.S. Geological Survey.