Armed with a new engineering report, the Minnesota Department of
Natural Resources is planning to ask lawmakers to fund a bubble
barrier at the Ford Dam on the Mississippi River to slow
invasive carp. The estimated cost of the project: $12 million to
$19 million. "The hope is this deterrent barrier, in conjunction
with the Coon Rapids Dam, would limit or slow the spread into
the Upper Mississippi River watershed," Steve Hirsch, the DNR's
ecological and water resources director, said Thursday, Jan. 3.
But nothing is simple when it comes to invasive species, and the
request is sure to force lawmakers to confront the uncertainties
-- and expense -- of trying to battle waterborne invaders. The
"acoustic/bubble/light system" is based on unproven technology
and "will not be 100 percent effective," according to Barr
Engineering, the Edina firm hired by the DNR to examine options
on how to stop or slow the advance of bighead and silver carp,
which have forced out native fish and animals in Illinois and
other points s