Press Release

Great Lakes Need Protection from Ocean and Freshwater Ships

New study demonstrates boats that never leave the lakes are moving invaders

May 31, 2018

Chicago, IL (May 31, 2018) –  A new report released today by the Great Waters Research Collaborative has found that lakers — ships that transit solely within Great Lakes waterways — contribute to the spread of aquatic invasive species among the lakes.

Ocean-going cargo vessels have introduced numerous destructive aquatic invasive species, such as zebra mussels and round gobies, into the Great Lakes. Aquatic invasive species have irreparably harmed the Great Lakes ecosystem and cost the region billions of dollars since the late 1980s. Although lakers don’t play a role in bringing aquatic invasive species into the Great Lakes, advocates have long questioned their impact on the spread of these harmful critters. In February, researchers announced the discovery of bloody red shrimp in the Duluth-Superior harbor on Lake Superior. Bloody red shrimp were brought into the Great Lakes via the ballast tanks of ocean-going vessels and first discovered in 2006 in Lakes Michigan and Ontario but had not yet been detected in Lake Superior.

The study documented five non-native species not yet established in western Lake Superior, including “bloody red shrimp” (Hemimysis anomala), in laker ballast water discharged there. It also detected, in uptake water, a species of zooplankton (Paraleptastacus wilsoni) that had not previously been recorded in the Great Lakes. Some of the species found live in harbor sediment and may have escaped routine surveillance. The study did not examine whether or not the collected non-native species might be able to survive or become established in western Lake Superior.

In response to the study’s release, Alliance for the Great Lakes President and CEO Joel Brammeier made the following statement:

“Today’s report confirms a common sense assumption: lakers contribute to the spread of aquatic invasive species around the Great Lakes. As such, all ships operating on the Great Lakes – oceangoing and lakers – must be accountable and stop introducing and spreading the biological pollution that is invasive species.

Unfortunately, the shipping industry is united in its lobbying efforts to convince Congress to remove U.S. EPA’s authority to strengthen protections for the Great Lakes from invasive species. While the shipping industry plays a role in the region’s economy by creating jobs and moving goods, it also has a collective responsibility to operate in a way that protects the Great Lakes for all who share them.

We are grateful that the Great Waters Research Collaborative has brought the academic, business, and conservation community together to conduct this scientific study. We also appreciate that the Minnesota Pollution Control Agency required this research as part of its existing ballast water permitting authority under the U.S. Clean Water Act. Sound science is the basis for strong policy to protect our region’s greatest asset: the Great Lakes.

Elected and agency officials must pay attention to this research and ensure that rules are in place requiring the cleanup of ballast water tanks on ocean-going ships and lakers. Without them, the Great Lakes environment and regional economy will continue to be harmed by aquatic invasive species.”


Media Contact: Jennifer Caddick,, (312) 445-9760