St. Louis River Estuary Restoration

At the mouth of the St. Louis River, on the border of Wisconsin and Minnesota, is the St. Louis River Estuary—a massive complex of wetlands that provide habitat for migrating waterfowl, shorebirds, and songbirds as well as declining species of breeding marsh birds. 

The St. Louis River Estuary and its surrounding region, has been identified by Audubon scientists as one of the 12 most important coastal wetland regions across the Great Lakes that are most important to conserve or restore for vulnerable marsh birds.

The Estuary has suffered from a legacy of industrial pollutants and was once one of the most polluted waterways in the United States. Despite this, much of the intact marshes remain in relatively high-quality condition, supporting exceptional bird diversity during migration and nesting seasons. 

More than 240 bird species have been recorded within this Audubon Important Bird Area and its numerous bays, islands, wetlands, barrier beaches, and forested areas. Many of these species are facing steep population declines. Black Terns, once common, have not bred in the estuary since the 1990s.

Marsh bird species including American Bittern, Least Bittern, Black Tern, and Yellow-headed Blackbird, all of which are Wisconsin Species of Greatest Conservation Need, depend on a unique habitat complex commonly referred to as hemi-marsh, which has disappeared across the Great Lakes region in parallel with population declines of these species. 

Drastically fluctuating lake levels have disrupted the delicate conditions that hemi-marsh habitat needs to thrive in the St. Louis River Estuary region.

Our work in the St. Louis River Estuary region is focused on restoring the highest-opportunity wetlands, such as Allouez Bay, where the growth of invasive cattails has made it difficult for wetlands birds to thrive, to revitalize marsh bird populations. Restoration strategies will protect sensitive areas from current and future impacts driven by a changing climate.