By Henry Brean
Posted: May 28, 2012 | 2:00 a.m.

The enemy is invisible to the naked eye and exists in numbers hard to comprehend - hundreds of trillions of them at every depth and in every cove.

In the five years since they were first discovered in Lake Mead, the population of invasive quagga mussels has grown tenfold.

UNLV researcher David Wong estimates that more than 1.5 trillion adult quaggas and 320 trillion microscopic mussel babies now populate the reservoir.

That's 80 to 160 quaggas for every gallon of water in the nation's largest man-made lake. If mussels were dollars, there would be enough of them to pay off the national debt 20 times over, with a few trillion bucks to spare.

Read More (Las Vegas Review Journal)