The Risk of Asian Carps to the Great Lakes: Results of A Major Bi-National Risk Assessment

Two species of Asian carp—Silver and Bighead—were imported into the United States into aquaculture facilities.  Through large flooding events in the 1980s and 1990s, these carps escaped into the Mississippi River, have reproduced successfully, and have expanded their range significantly.  In parts of the Mississippi River system (which includes the Illinois River), these carps have become dominant and disrupted the ecosystem, causing ecological, economic, and personal harm.  The Chicago Area Waterway system—a manmade canal that connects the Great Lakes to the Mississippi River system—is one pathway of concern for these carps to enter the Great Lakes.  Deep concern exists throughout the region that the carps could disrupt the Great Lakes in the same way they disrupted the Mississippi River system.  Officials from Canada and the United States must make decisions about prevention, rapid response, and control of Asian carps in light of uncertainty surrounding the likelihood of Asian carp arrival, survival, establishment, and spread into the Great Lakes ecosystem.  A binational risk assessment of Asian carps in the Great Lakes was identified as a need by Great Lakes fishery managers.  A risk assessment is a scientific process that structures best available information concerning invasive species, and addresses the uncertainty in a peer review setting, to provide defensible scientific advice.  The Asian carp risk assessment includes a large volume of scientific information and provides direction for prevention, response, and control activities. The paper presents the binational ecological risk assessment including a discussion of how the assessment was conducted, the elements of risk, and the overall level of risk these Asian carps pose to the Great Lakes.