Field Notes
U.S. Fish & Wildlife Service
Field Notes Entry   
Fish and Wildlife Populations and Habitat Impairments Removed in the U.S. side of the St. Marys River Area of Concern
Midwest Region, September 25, 2019
Print Friendly Version
The St. Marys Lower Rapids and fish flow freely under the newly constructed bridge that replaced an earthen berm.
The St. Marys Lower Rapids and fish flow freely under the newly constructed bridge that replaced an earthen berm. - Photo Credit: John Riley, Michigan Department of Environment, Great Lakes, and Energy

The St. Marys Little Rapids and spawning fish are back! Rapids restoration efforts in 2015-2016 removed an earthen causeway between Sugar Island and a small island with ferry docks (a.k.a. Island Number One), which had resulted in the loss of rapids conditions and fish spawning habitat. A bridge spanning approximately 600 feet replaced the causeway, allowing water to once again freely flow and create rapids conditions, improving fish and wildlife habitat in at least 50 acres. Habitat monitoring for two years before and two years after restoration showed that water velocity increased and scoured silt from the river bottom, exposing a rocky substrate once again. The return of fast-moving waters and a rocky bottom led to fish spawning and increases in larval and adult fish numbers of desirable native and sport fish including walleye, salmon, and sturgeon. The post-restoration return of aquatic insects indicative of highly oxygenated, good water quality also indicated improved ecosystem health. These insects also can provide a high-quality food source for fish that have returned to the Little Rapids.


These multiple lines of evidence of improved fish and wildlife habitat and populations supported the removal of two wildlife Beneficial Use Impairments (BUIs) from the U.S. side of the St. Marys River binational Area of Concern (AOC) in fall 2019. Based on the overall ecosystem uplift demonstrated during monitoring, the U.S. Fish and Wildlife Service supported the removal of the Degradation of Fish and Wildlife Populations and the Loss of Fish and Wildlife Habitat BUIs. The removal of these two wildlife BUIs leaves only three of the original ten BUIs in U.S. waters to be removed before this AOC is delisted entirely and marks a major step in restoring ecological function to the St. Marys River.

Contact Info: Carly Eakin, 517-351-5293, carly_eakin@fws.gov
Find a Field Notes Entry

Search by keyword

Search by State

Search by Region

US Fish and Wildlife Service footer