ROANOKE TIMES
Copyright (c) 1997, Roanoke Times
DATE: Tuesday, February 18, 1997 TAG: 9702190038
SECTION: NATIONAL/INTERNATIONAL PAGE: A-4 EDITION: METRO
DATELINE: SEATTLE
SOURCE: Associated Press
An alien invasion threatens the United States, biologists warned Sunday, and they're calling for a government commission to investigate the menace.
So many small sea creatures from Asia, Europe and other distant shores are turning up on America's coasts that in some places, the native inhabitants can hardly be found.
The invaders - crabs, clams, worms, snails and mussels - travel in cargo holds, ship ballast tanks and even bait shipments, yet the public is largely unaware and the government is having a hard time stopping the onslaught.
The problem is so severe that biologists have asked the White House to do something about it. In a letter they plan to send to Vice President Al Gore next month, more than 200 scientists are calling for a presidential commission to study the threat.
``We are losing the war against invasive exotic species, and their economic impacts are soaring. We simply cannot allow this unacceptable degradation of our nation's public and agricultural lands to continue,'' the scientists wrote.
There are comparable problems in other environments. In the rivers and lakes of central and eastern North America, invading zebra mussels clog water intake pipes and push out native species. And on western rangelands, foreign weeds are crowding out thousands of acres of native grasses a day.
``A marine biologist returning to New England after an absence since 1970 would find a very different world today,'' said James Carlton, a professor of marine sciences at Williams College.
When an exotic invader settles in a new environment, it competes for resources with native species, often with undesirable consequences. European green crabs, for example, crowd out the tasty blue crabs that are caught from the mid-Atlantic to the Gulf of Mexico.
The overall impact of the invasion is unknown.
``We really only have a handful of studies,'' said Edwin Grosholz of the University of New Hampshire. ``We just really don't have any information about what they've done.''
At the symposium, held during the annual meeting of the American Association for the Advancement of Science, researchers shared vivid descriptions from the front lines of the war against exotic species.
Andrew Cohen of the University of California, Berkeley, said that in some parts of San Francisco Bay, rocks and piers are so covered with invading species that native species can no longer be found. The bay is thought to be the most invaded ecosystem in the world, with 234 non-native species known and a new one moving in every 12 weeks.
``We will never have a natural San Francisco Bay ecosystem again,'' Cohen said. ``We need to get very serious very quickly.''
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