DETROIT (AP) - Schools of small fish are capable of crossing an electrical
barrier designed to keep Asian carp from using the Chicago ship canal to
enter the Great Lakes, according to a new research report from the U.S.
Army Corps of Engineers.
There is no evidence that Asian carp are bypassing the barriers, which
were established to prevent billions of dollars in potential damage to the
Great Lakes fisheries, according to the report released by the Army Corps’
But the research shows that passing vessels can pull the fish past the
barriers while also causing fluctuations in the electrical field, the
report said. It was released Friday.
“Initial findings indicate that vessel-induced residual flows can trap
fish and transport them beyond the electrical barriers, and that certain
barge configurations may impact barrier electric field strength,” the
report said. “Additionally, the preliminary ... findings identified the
potential for small fish (between 2-4 inches in length) to pass the
barrier array in large groups, or schools.”
The Army Corps of Engineers and the U.S. Fish and Wildlife Service have
conducted both laboratory and field experiments to “assess the potential
impacts of barge tows traversing the electrical dispersal barrier system”
in the canal.
The report said there is no sign of an immediate threat of Asian carp
traveling through the canal, which links the Mississippi River watershed
to the Great Lakes.
“There is no evidence that Asian carp are bypassing the barriers. Nor is
there any indication that Asian carp are in the vicinity of the barriers,”
it said. “The closest adult Asian carp found in the Illinois River are
about 55 miles from Lake Michigan, and no small Asian carp have been
observed closer than 131 miles from Lake Michigan.”
More study is needed to learn more about how well the electrical barrier
is functioning, the report said.
“Future research will include a variety of simulations to further evaluate
fish behavior, effects of the electrical field on groups of fish and how
these may relate to operational protocols of the barriers and navigation
within” the Chicago Sanitary and Ship Canal, it said.
The electrical barrier is meant to block Asian carp’s path toward Lake
Michigan. Just one live Asian carp has been found beyond that point,
although numerous DNA samples have turned up past the barrier and in Lake
Asian carp website: