Investigation of Great Lakes Tributaries for Asian Carp Spawning and Egg-Transport Suitability
Two Lake Michigan tributaries (the Milwaukee and St. Joseph Rivers) and two Lake Erie tributaries (the Maumee and Sandusky Rivers) were investigated to determine if they possess the hydraulic (water velocity and turbulence) and water-quality characteristics to allow successful spawning of Asian carps. All four tributaries exhibited potential egg settling zones for Asian carp eggs within the lower 62 miles of the river; however, all four rivers also exhibited sufficient temperature and transport times outside of settling zones for successful suspension and development of Asian carp eggs to the hatching stage. Egg settling zones refer to areas where eggs fall to the river bottom and will likely die. These observed data indicate that these four Great Lakes tributaries have sufficient hydraulic and water-quality characteristics to support successful spawning and recruitment of Asian carps. The data indicate that river reaches as short as 16 miles may allow Asian carp eggs sufficient time to develop to hatching and that eggs settle at mean velocities in the range of 5.9-9.8 inches per second, a much lower value than is generally cited in the literature. The minimum transport velocity for the eggs in a river can be estimated by using mean flow depth and river substrate data using curves presented in the report. These findings expand the number of possible tributaries suitable for Asian carp spawning and contribute to the understanding of how hydraulic and water-quality information can be used to screen additional rivers in the future.
This is a GLRI/USGS funded project in the Asian Carp Control Strategy Framework (Action Item 2.5.11).