Using fish raceways to do controlled experiments, John Chick and Mark Pegg of the Illinois Natural History Survey are testing the potential effectiveness of the present electric barrier, as well as exploring additional barrier technologies as they relate to Asian carp. Two species of Asian carp, bighead and silver, are migrating closer to the actual barrier site, located near Romeoville, Illinois, and have been spotted as close as 25 miles from Lake Michigan.
Thus far in the study, there were 381 attempts by bighead carp to pass through the simulated barrier--379 times the fish turned around. Only one fish went through the barrier, and in fact, did it twice.
"This was a smaller carp, which was not surprising. Smaller fish are less susceptible to the electric current," said Pegg. These tests were done for six continuous hours per day for three days.
Asian carp, which have grown to 50 pounds in U.S. waters, were brought here for use in aquaculture in the 1970s, and escaped into the Upper Mississippi River System. The populations of these species have increased dramatically in some areas.
"Asian carp consume zooplankton, which all fishes typically feed on in their juvenile stages, so they have the potential to adversely affect every species of fish in the Mississippi River and Great Lakes," said Pegg.
The electric barrier was turned on in April in an effort to stop non-native
fish from moving between the Great Lakes and the Mississippi River basin. The idea is that as fish pass through the barrier, they feel
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Contact: Ben Sherman
sherman@nasw.org
202-662-7095
National Sea Grant College Program
22-Jul-2002