Making a home for fish and wildlife in the Detroit River’s ‘Conservation Crescent’

Grosse Ile resident Bert Urbani was looking out her window several years ago when she spotted 19 bald eagles fishing in the partially frozen-over Detroit River. “When you see a sight like that, it carries weight,” says Urbani, who also works as communications co-chair for the Grosse Ile Nature and Land Conservancy. 

Grosse Ile is nestled in the south end of the Detroit River between shorelines mixing industrial, residential, and natural environments. It’s one of an archipelago of islands, shoreline areas, and wildlife refuge units including Sugar Island, Calf Island, Humbug Marsh, Refuge Gateway, and Gibraltar Bay as well as Elizabeth Park, the first established county park in the state. Known as the Conservation Crescent, the region is home to an array of wildlife that takes advantage of diverse and rare habitats and unique geography. 

More than 3,000 acres are protected in the region. The White Sands Conservation Area is located on the southern end of Boblo Island in Canada, and Grosse Ile contains deed-restricted marshes and land. Nearby is Lake Erie Metropark. Overall, the Detroit River International Wildlife Refuge itself consists of almost 6,000 acres along 48 miles of the Detroit River and Lake Erie shorelines.  

The bald eagle, previously endangered, is now a regular feature of the Crescent, and just one example of the diverse wildlife coming back to the area thanks to local conservation efforts. 

But although preservation and conservation efforts aim to protect these islands, ongoing challenges, including legacy contamination from industry, climate change, and development pressure continue to threaten their ecological and recreational value. 

An unknown asset

This history of each of the individual islands in the crescent is varied—they have been used for farmland, industry, and even two amusement parks: one on Boblo and one on Sugar Island. Many metro Detroiters may not know about the islands because of the region’s history of racism and segregation and a historical lack of efforts to welcome Black people into natural spaces, Urbani says. 

Recently, the International Wildlife Refuge Alliance has been working on altering bus routes to include a stop at the Wildlife Refuge visitor center so that it will be more easily accessible to Metro Detroiters. The Outdoor Adventure Center in Detroit also helps to bridge this gap, Urbani says, by helping people become familiar with nature. 

Dr. John Hartig, a Fulbright scholar at the Great Lakes Institute for Environmental Research and previous manager for the Detroit International Wildlife Refuge for 14 years, says there will be “amazing opportunities for education and kids and families” once the Humbug Marsh visitor center is open. Students will be able to take a field trip to the Outdoor Center in the morning, and visit Humbug in the afternoon, he says. The visitor center and Refuge Gateway, they expect, will be as welcoming, diverse, and popular as the Detroit Riverwalk. 

A smattering of other initiatives to make the area more accessible includes the International Wildlife Refuge Alliance’s bus fund to offset transportation costs for schools to attend the Crescent, a mobile classroom (put on hold due to COVID-19) to teach in local parks, and Michigan Sea Grant’s sponsorship of students who want to attend the bi-national State of the Straight Conference. Connecting everything, the greenways, like the planned Joe Louis Greenway, and the blueways, like the Detroit River Heritage Trail, are an important part of making the Crescent accessible as well, Hartig says. 

An ‘unusual’ ecosystem

The Conservation Crescent was affectionately named in the early 2000s by the late Bruce Jones, co-founder of Grosse Ile Nature and Land Conservancy and founding member of the International Wildlife Refuge Alliance. 

“There’s so much wildlife in those areas,” says Mary Bohling, extension educator for Michigan Sea Grant and chair of the Detroit River Public Advisory Council. “Especially in an urban setting, it’s just so unusual.” 

That’s one reason why groups like the Friends of the Detroit River, Grosse Ile Conservancy, and the U.S. Fish and Wildlife Service are working to protect the Crescent. The area provides habitat for a number of species, including the endangered channel darter, 150-year-old oak trees, walleye, and even, for the first time in years, wild turkeys. 

The area was designated as an Important Birding Area (IBA) by Audubon; it’s a place where you can find 10 percent of the global population of canvasbacks as well as plenty of tundra swans, black ducks, mallards, and the previously endangered osprey. 

The Detroit River is at the intersection of two crucial pathways for migratory birds: the Atlantic and the Mississippi flyways. In their migration south, hawks head to the mouth of the Detroit River where the islands give off heat. The heat forms columns that rise up and the hawks use these thermals to “glide” from island to island. 

The small islands within the Crescent act as an essential link for surrounding ecosystems, according to Hartig. Fish use it as a spawning habitat. Deer swim over from Grosse Ile or Canada. And many birds, like turkeys or hawks, use the islands as a flyover spot. 

“Each of those islands provides unique stopover habitat for birds on migrations,” says Hartig. 

A legacy of challenges, and some new ones

The islands continue to be threatened by development and pollution. “We are the industrial heartland,” Hartig says. “We were the arsenal of democracy, and the legacy pollution from all of the industry is in the sediments.” 

One significant challenge includes remediating five million cubic meters of contaminated sediment throughout the Detroit River between the old Uniroyal site off East Jefferson Avenue downstream through Trenton. Pollutants such as PCBs, polycyclic aromatic hydrocarbons, metals, and oil can be found in this area, the result of decades of industrial pollution laid down in the 1950s and 60s. “More has to be done to restore and clean and make this ecosystem safe for fish, wildlife, and humans,” Hartig says. Current remediation efforts of the river focus upriver and have not yet reached the Crescent. 

This fall, the Detroit River Conservancy and the EPA started a $2.9 million remediation project to clean up one acre of sediment on the banks of the river west of the MacArthur Bridge at the former Uniroyal site. The two groups also signed a $2.5 million remediation agreement for the Ralph C. Wilson Jr., Centennial Park. 

In addition to legacy contaminants, Hartig says the waters around the islands receive a heavy burden of nonpoint source pollution in the form of stormwater runoff from the surrounding urban watershed. A recent University of Michigan study found that around 80 percent of the phosphorus pollution in the Detroit River comes from nonpoint source pollution. Phosphorus pollution contributes to Lake Erie’s toxic algal blooms that pose a risk to wildlife, recreational opportunities, and drinking water. 

As you circle Sugar Island, one of the larger undeveloped islands in the archipelago, the erosion from record-high Great Lakes water levels is evident. Multiple large trees, one still full with green leaves, lay in the water. What was once grassy land that extended into the water an additional 100 feet compared to the present shoreline is now a 10-15 foot bluff of soil and exposed tree roots. In addition to rising water levels, the increased frequency of severe weather events are affecting coastal wetlands, according to Hartig.

Protecting and connecting

Robert Burns, the Detroit River’s Riverkeeper, is involved with numerous projects aimed at preserving Sugar Island and the Crescent. Since 2003, Burns has been involved in more than 60 conservation projects, navigating the river by boat to help coordinate research projects, restore habitat, conduct maintenance, report pollution, and study fish spawning.

Burns and other conservationists plant to mitigate the effects of erosion on Sugar Island by constructing shoals — long stretches of limestone rock that break up the energy of the waves. Celeron Island and Stony Island already have constructed shoals. In addition to reducing the effects of high waters, the shoals provide other habitat services to the ecosystem. Terns, herring gulls, ring gulls, and even osprey can be found resting on them, and they provide important spawning habitat for fish. 

The fishery in the crescent is a valuable resource. “the western basin of Lake Erie is the Walleye Capital of the world,” says Chris Vandergoot, associate professor in the department of fisheries and wildlife at Michigan State University. The area where the Detroit River meets Lake Erie was a prime spawning habitat for “just about every fish species in Lake Erie” before the river was dredged to allow vessels to move through it.  Even so, he says, “There’s still no better place in North America for walleye to exist.” 

Fishing and hunting are “a huge part of the economy around here,” says Urbani. Detroit made the top 10 for metropolitan waterfowl hunting spots in a list produced by Ducks Unlimited. Thirty different species of waterfowl and 300,000 ducks stop there each year to rest and eat the wild celery. 

Walleye are usually found in deeper waters, and a new fishing pier completed this year at the Detroit River Refuge Gateway and John D. Dingell Jr. Visitor Center will allow fishers without boats to experience some of the great fishing found in these deeper waters. 

But conservation in the crescent is about more than wildlife. Sugar Island, located southeast of Grosse Ile, is also a recreational spot important to many birders, anglers, kayakers, swimmers, nature lovers, and hunters. “Besides Belle Isle, it’s the only sandy beach on the Detroit River,” Bohling points out. 

Reflecting on the past 15 years, Hartig is proud of how far the dream of the Conservation Crescent has come since its inception more than 15 years ago.

“If you look at it, it’s kind of amazing how much of it is protected now,” Hartig says.