Brief History: Invasive Species

Not since jaws has a piscine predator caused such a commotion. Asian carp--which grow up to four feet long, feast ravenously on other species' food and have a nasty habit of leaping from the water to wallop unsuspecting fishermen--are threatening to take a bite out of the Great Lakes' $7 billion fishing industry. To reassure jittery local governments, the White House held an Asian-carp summit Feb. 8 and pledged $78.5 million to help keep the fish--brought to the U.S. in the '70s to rid catfish farms of algae--at bay.

Until humans learned how to build ships, the problem of invasive species--nonnative flora and fauna that can quickly overrun an ecosystem--was virtually nonexistent. With the dawn of global trade, transporting critters to new continents was encouraged. Beginning in the 16th century, farmers in North America introduced wheat, rice, soybeans and cattle, among other imports, which today make up huge portions of U.S. food production.

But some arrivals have been devastating. Gypsy moths, brought to Massachusetts in 1869 by a would-be silk farmer, managed to escape and strip the leaves from millions of acres of forest. Descendants of some 100 starlings unleashed in New York City in 1890 now number 200 million, crowding out native birds from coast to coast. The Japanese vine kudzu was transplanted to the U.S. to prevent erosion; it has since run roughshod over 10 million acres (4 million hectares) in the Southeast. Beginning with the Plant Quarantine Act of 1912, the U.S. has implemented a series of laws to strengthen its eco-defenses, many seeking to prevent dangerous wild things from reaching American soil (a more realistic goal than controlling them once they arrive). Worldwide, invasive species cause an estimated $1.5 trillion in damage every year, nearly 5% of global GDP. Lake Michigan could be next.