Invasive, exotic species gaining ground, or water, and posing major threat to native U.S. wildlife

Those Asian carp we reported on a few weeks ago have finally invaded the Great Lakes, putting themselves at the top of a long list of invasive species posing a wide range of problems. Sam Hamilton, director of the U.S. Fish and Wildlife Service, told Juliet Eilperin of The Washington Post that exotic species are "probably the single greatest threat in our country to our native wildlife." Eilperin sums up the problem nicely:

"Which is worse? Closing two locks on a waterway that's used to ship millions of dollars' worth of goods from the Great Lakes to the Mississippi basin? Or allowing a voracious Asian carp to deplete the food supply of native fish sustaining a Midwestern fishing industry that nets $7 billion a year? And how do you put a price tag on the damage caused by the Burmese python and other constrictor snakes that are strangling the precious ecology of the Everglades?"

The U.S. Army Cops of Engineers has failed twice to stop the carp with electric barriers in the Chicago Sanitary and Ship Canal, but is hoping a third try will be charmed. "The barriers are not surefire," Eilperin reminds readers, "and experts say it's difficult to say how many Asian carp would have to make it through to establish a viable population." She notes that the carp were imported by Southern fish farmers to eat pond algae and escaped during floods, and "Now the fish so thoroughly dominate the Illinois River that communities have annual fishing tournaments targeting them." (Read more)