Detroit River AOC - Sugar Island Habitat Restoration
Funding Agency: NOAA
Project Budget: $260,000
Start Date: August 2017
End Date: December 2018
Sugar Island is an uninhabited, 30-acre island at the mouth of the Detroit River near Lake Erie. It is entirely owned by the U.S. Fish and Wildlife Service (USFWS) as part of the Detroit River International Wildlife Refuge. This area of the Detroit River serves as one of the most important spawning areas for western Lake Erie. Significant positive recreational and economic impacts are anticipated as a result of this project that will enhance quality of life for southeast Michigan and northwest Ohio and further strengthen the Great Lakes fishery, worth $4-7 billion annually.
In the early part of the 20th century, Sugar Island hosted a resort park that included a large roller coaster, merry-go-round, bathing beach and large dance pavilion. Access to the island was by steam ferry, such as the SS Tashmoo. By the 1940s, the park fell into disrepair and various plans for revitalization never advanced. In 1954, the dance pavilion burned to the ground and a visible connection to an illustrious past was lost. Until recently, as was done 130 years ago, small watercraft would beach or drop anchor to picnic and explore the island. In 2012, Sugar Island was purchased by the USFWS with Great Lakes Restoration Initiative (GLRI) funding for inclusion in the Detroit River International Wildlife Refuge.
The island has reverted to a natural state that contains remnants of valuable upland and aquatic, shoreline habitat. The Detroit River is a known migration corridor for many birds and insects, thus Sugar Island is a stopover site during migration for a wide range of species. Forests, like that on Sugar Island, are especially important for dozens of species of neotropical migrant passerines. Heavy use of the island in spring and fall by sparrows, kinglets, warblers, vireos, orioles, and tanagers is frequently observed. Hundreds of thousands of blue jays annually travel over this area around western Lake Erie. As a result, the migration of raptors is monitored and well-documented to utilize this concentration of migrant songbirds as prey. These raptors include: sharp-shinned hawk, Cooper's hawk, northern goshawk, broad-winged hawk, and red-shouldered hawk. The sand beaches are used for hunting by merlin, red-tailed hawk, bald eagle, and northern harrier.
Fish in the shallow waters around Sugar Island are diverse, including largemouth, smallmouth, and white bass, bowfin, bullhead, gar, pike, rock bass, blue gill, pumpkinseed, emerald shiner, and yellow perch. Of note is the presence of the channel darter, a Michigan endangered species.
Project Scope: Because the southern end of Sugar Island faces western Lake Erie, it is exposed to high wind and wave action. As a result, approximately 10% of the island has been lost to erosion in recent decades. This project explores the ecological value and feasibility of controlling shoreline erosion while enhancing fish and wildlife habitat. A science-based feasibility study is underway with assistance from SmithGroupJJR and input from fisheries and wildlife scientists from the United States Geological Survey (USGS), Michigan Office of the Great Lakes (OGL) and the USFWS.
Construction of protective shoals around the island's south end is one idea to control shoreline erosion and protect the coastal wetland. However, this strategy has not been scientifically verified to be viable.
Projects of this magnitude and importance need to be formulated by considering the subsurface riverbed from both structural (load bearing) and sediment character (potential contaminants and sediment transport) standpoints. This project includes a comprehensive evaluation of sediments in the vicinity of Sugar Island. Furthermore, analysis of the island's shoreline geology, river flow characteristics surrounding the island and existing vegetation on the island and in the nearshore are under consideration to formulate potential design alternatives.
Regarding the hydrology around the island, it is critical to understand how the cross dike from the Livingstone Channel has influenced flow. One hypothesis is that the island has eroded from accelerated flow wrapping around the isle's southern tip, now 120 years since the cross-dike was constructed. Once a cliff-face forms, other erosive forces like precipitation, wind and tree fall act on that face, and the river may be a secondary force causing the island's erosion. In this case, stabilization may require regrading to take away the cliff face. Conversely, the face of this cliff may be excellent habitat for bank swallows and kingfishers, which would warrant stabilizing the cliff as it is, in some manner, without regrading.
This investigation includes mathematical modeling to understand how this ecosystem functions and to predict changes in flow, nearshore dynamics, sediment transport, erosion rates, etc. that may result from proposed habitat restoration actions. Findings from this investigation and feasibility study will be used to select habitat restoration actions if warranted. Such sound scientific investigation is the foundation of restoration efforts.
Project Outputs/Outcomes: This project will establish practical limits of upland, wetland and submergent habitat that can be restored within the degraded and eroded areas on and adjacent to Sugar Island. Preliminary discussions suggest that over 1,000 linear feet of coastal shoreline and approximately 5 acres of marsh and submergent habitat can be created and/or protected from further degradation. Up to 30 acres of upland habitat can be enhanced. A final determination of the project outputs will be published upon completion of this project.
Sugar Island Location Map
The Island has transitioned from an amusement park to an uninhabited forest.
The island's south end is an eroding cliff-face losing sediment into the adjacent nearshore.
Sugar Island Erosion Since1937
The cross-dike east of the island accelerates flow along the isle's southeast side.