The U.S. Army Corps of Engineers released a study looking at how to
prevent invasive species like the Asian carp from entering the Great
Lakes. None of the solutions is foolproof, it said.
By Mark Guarino
CHICAGO — To keep Asian carp and other invasive species out of the
Great Lakes will require at least 25 years and billions of dollars,
according to a study released Monday by the U.S. Army Corps of
The report, commissioned by Congress in July 2012, offered eight
strategies for protecting the Great Lakes ecosystem from an
infiltration of at least 13 invasive species moving upstream from the
Mississippi River. Six of the options include permanent barriers,
which independent authorities say is most foolproof, but which
threatens barging interests.
The corps did not recommend which option it considers most effective,
but Dave Wethington, Chicago-area waterway system project manager for
the U.S. Army Corps of Engineers, told reporters Monday that physical
separation has the greatest “ability to buy down risk.” None of the
options are guaranteed to fully prevent invasive species from reaching
the Great Lakes, he added, because the carp will still have the
potential to bypass the barriers via intentional or accidental bird or
human transfer. Other forms of invasive species, like red algae or
reed sweetgrass, may have greater success in breaching the barriers.
“There is a residual risk for all of these [options],” Mr. Wethington
said. “The ultimate decision is up to the collaborative group of
The study focuses on the Chicago Area Waterway System (CAWS), a
128-mile stretch of canals and rivers in metropolitan Chicago
connecting Lake Michigan and the Mississippi River. Environmental DNA
evidence of live Asian carp has been discovered in and around CAWS for
several years, triggering an outcry from officials in all the Great
Lakes states for more federal action. Carp would threaten a $7 billion
annual recreational and commercial fishing industry.
Congress will need to authorize any new plan. Wethington emphasized
that the cost will be shared among federal, state, and local agencies.
The “best possible scenario” for a start date is 2017, but that
depends on speed: how fast Congress authorizes a plan, as well as how
fast subsequent local permitting and environmental review periods
take. The 25-year estimate includes both design and construction
The eight plans include a combination of structural controls (such as
screened gates, locks, electric and physical barriers), nonstructural
controls (such as pesticide use, education, and mechanical removal),
and a buffer zone (such as waterways created to control
up-and-downstream water flow). Wethington said that cost estimates of
each plan include the construction of reservoirs, sediment
remediation, and other methods needed to protect the surrounding
communities from floods or drinking-water contamination.
“We wanted to make sure [any plan] did not have an adverse impact on
the way the system operates today,” he said.
The corps is soliciting public input through a series of public
meetings throughout the Midwest. The first is Thursday in Chicago, the
last is Jan. 30 in St. Louis. Some of the meetings will be streamed
online. Comments will be accepted through March 3 via the agency’s
A coalition of conservation leaders from the Great Lakes that is
advocating for a permanent barrier says it will comment further on the
report Tuesday. In the meantime, the organization released a statement
saying, “actions that do not move [toward a barrier] are a distraction
that further delays the permanent solution so desperately needed
The Asian carp is a bottom-feeder fish that was introduced to catfish
farms in Mississippi and Arkansas in the 1970s to help control algae
growth. The fish is presumed to have traveled to Chicago through the
Mississippi River, which connects to Lake Michigan through the Chicago
Sanitary and Ship Canal.