Advocacy groups want President Barack Obama to support further study of long-term measures to prevent Asian carp and other invasive species from migrating between the Great Lakes and Mississippi River watersheds.
A 30-member panel representing governments, businesses and environmentalists has sought region-wide agreement on how to close aquatic pathways in the Chicago area linking the two giant water systems without damaging shipping and recreation.
In a letter this week, the Chicago Area Waterway System Advisory Committee asked Obama for a study of "control points" such as specially designed locks that would let boats to move back and forth while stopping fish, mussels and other live organisms from doing likewise.
The study would be conducted by the U.S. Army Corps of Engineers, which would make recommendations to Congress and other officials.
Explore further: Efforts to close canal to Great Lakes