Aliens invaders choking life from Nevada environs

Friday, March 31, 2000 | 11:26 a.m.

Foreign invaders such as killer bees and tamarisk, the salt-loving plant choking Las Vegas wetlands today, have traveled all over the world, biologist Harold Mooney said.

While it once took hundreds of years to change the landscape as alien seeds and animals hitchhiked in a ship's cargo, today with airmail and global commerce, the environment can change overnight, Mooney said Thursday before accepting the 13th Nevada Medal.

Along with a $10,000 prize, the Nevada Medal is an 8-ounce medallion of silver given annually to a national leader in science or engineering. The award is sponsored by the shareholders of Nevada Bell.

"It is the rate of change -- very dramatic -- that is causing the concern," he said Thursday during a lecture in Las Vegas at the Desert Research Institute, the research arm of the University of Nevada System.

While society is spreading star thistle and cheat grass all over the world and destroying grazing lands, some perceived threats both harm and help people and the environment, Mooney said.

Africanized bees, for example, escaped from a laboratory in Brazil during 1956. On Monday they stung a 77-year-old Las Vegas woman 500 times. She is in fair condition at University Medical Center, one of thousands of victims in South and Central America, Mexico and the United States to be attacked by the Africanized bees, popularly called killer bees because they are so aggressive.

The killer bees have lived up to their name, fatally stinging 1,000 people in their 44-year flight north.

Yet these bees saved parts of the Amazon rainforest, Mooney said. After Amazon forests were clearcut, the bees found individual plants surviving and pollinated them, reviving the devastated environment.

Mooney and other scientists like him are trying to educate corporations about the threat from such alien invasions, using science as a tool to find out what happens for either benefit or harm. He is heading up a global effort to deal with World Trade Organization members who believe scientists have to prove such rapid changes from industrial growth harm the environment.

"It's the other way around, they should prove there is no harm," Mooney said. "We are in a new world, but we have to know what is happening first."

The annual pricetag in damages from alien invaders to U.S. industries is $138 billion. In Southern Nevada hundreds of condos built on a couple of acres can wipe out up to 30 native species of plants, animals, insects and birds or their habitat, since deserts are more fragile than many other environments, he said.

While Southern Nevadans volunteer to help remove trash on April 8 in the Las Vegas Wash, removing tamarisks, those pesky salt cedars, one by one is expensive and time consuming, Mooney said.

Southern Nevada is not the only place on earth troubled by tamarisk. Australia has destroyed the plants by hand, just like the work in the local wash, said Mooney, a member of the National Academy of Sciences. It is worth the hard work for a healthy wildlife habitat and the benefits of a wetlands that filter out harmful pollutants, he said.

In addition to alien plants and animals, the largest threat to the planet is fragmenting habitats, Mooney said. That leads threatened species to extinction. The benefits lost from extinctions for future food sources or medical cures is incalculable.

Mary Manning covers environmental issues for the Sun. She can be reached by calling (702) 259-4065 or e-mail: manning@lasvegassun.com