Different types of barrier methods and technologies are developed and used to modify or close canals and waterways to reduce the risk of AIS moving between watersheds.
- Natural and artificial connections between water bodies exist across the Great Lakes Basin to facilitate commercial and recreational transportation, flood control, and for other purposes.
- Connecting canals and waterways also present a risk for aquatic invasive species movement.
- Structural and non-structural barriers and other technologies can be used to modify or close canals and waterways, re-establishing natural separation of the Great Lakes from other watersheds and preventing species movement.
The extensive canal and waterway system in the Great Lakes region, while used beneficially for transportation, managing water levels, and other purposes, establishes connections between watersheds that provide a pathway for aquatic species movement. The Chicago Sanitary and Ship Canal, an engineered waterway that connects the Mississippi River and Great Lakes watersheds, has provided an inter-basin pathway for AIS such as the round goby. Now, a significant concern is the migration of silver, bighead and black carp through the Chicago waterway system and the Mississippi and Ohio river systems, toward the Great Lakes basin.
In addition, the process of repairing and/or replacing aging water infrastructure presents additional risk of AIS movement between and within watersheds. Many restoration efforts across the Great Lakes basin involve the removal or repair of dams and other water infrastructure which could inadvertently facilitate the spread of AIS by opening previously inaccessible waterway segments. Decision-support tools can help agencies consider AIS risk when developing these projects.
Dispersal barriers, flood control barriers, physical barriers and other separation mechanisms may be used to prevent AIS movement across basin boundaries through canals and waterways. Agencies and other partners are researching, developing and implementing these technologies and targeting high-risk locations across the Great Lakes Basin. Through the Great Lakes and Mississippi River Interbasin Study, the Army Corps of Engineers identified, evaluated and recommended actions to address 18 different connection points between the Great Lakes and Mississippi River watersheds. Several states have taken steps to close some of these pathways, such as Eagle Marsh in Indiana and Little Killbuck Creek in Ohio.