Tuesday, November 24, 2009

Voracious, invasive Asian carp may be closer to the Great Lakes than thought

Last year we reported that the U.S. Army Corps of Engineers was fighting to keep the Asian carp from the Great Lakes. The latest data show the fish may be closer to Lake Michigan than previously thought. To halt the carps' migration toward the lake, the Corps built an underwater electric fence across the Chicago Sanitary and Ship Canal two miles from the lake. David Lodge, director of the Center for Aquatic Conservation at the University of Notre Dame, recently performed "environmental DNA" tests that show the carp may be north of the barrier.

"You can think of this e-DNA as the equivalent for environmental protection of, say, using DNA in crime fighting to detect whether someone was at the crime scene," Lodge told Robert Seigel of National Public Radio's All Things Considered. "So, we don't actually have a body, but we have DNA." The fish were originally brought to the U.S. to control nuisance algae, but they escaped and migrated to the Mississippi River basin. The Chicago canal connects the system to the lake.

The carp are highly invasive, with huge appetites, and Lodge and other scientists fear they could overwhelm native Great Lakes species, NPR reports. Lodge told Seigel he doesn't know for sure what effect the carp would have on the Great Lakes, but "there's lots of reasons to think they would be highly damaging." Even though his data show carp may be closer to the lake than previously thought, Lodge says its important to go ahead with previous plans to poison a 5- to 6- mile area near the canal to reduce carp populations. (Read more)

UPDATE, Dec. 8: Mark Guarino of the Christian Science Monitor reported Dec. 4 on the Dec. 2 poisoning of the canal, the possibility of Michigan suing Illinois, and more drastic action, such as closing a lock on the canal or closing the canal permanently.

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