Loss and degradation of fish and wildlife habitat is a long-standing issue in the Detroit River. The Detroit River Remedial Action Plan helped agencies and stakeholder groups reach agreement on impaired beneficial uses, including loss of fish and wildlife habitat, and helped mobilize all stakeholders to rehabilitate habitat. Many organizations played key roles, including the Detroit River Public Advisory Council, Detroit River Canadian Cleanup, State of the Strait Conferences, American and Canadian Heritage River Initiatives, Detroit River International Wildlife Refuge, and Western Lake Erie Watersheds Priority Natural Area. Accomplishments include: 14 habitat restoration projects on both the Canadian and U.S. side of the Detroit River; 53 soft shoreline engineering projects in the watershed; nine fish spawning reefs in the river, Common Tern habitat in four locations; and many wetland and green infrastructure projects. Based on Detroit River habitat restoration efforts over the last 32 years, the following advice is offered: reach agreement on severity and geographic extent of the problem; practice adaptive management; involve habitat experts up front in project design; establish quantitative targets for project success; ensure sound multidisciplinary technical support; start with demonstration projects; treat habitat projects as experiments; involve citizen scientists in monitoring; measure benefits; communicate and celebrate successes; promote education and outreach.
In 1985, 42 Great Lakes Areas of Concern (AOCs) were identified by the International Joint Commission’s Great Lakes Water Quality Board where Canada-U.S. Great Lakes Water Quality Agreement objectives or jurisdictional standards, criteria, or guidelines, established to protect beneficial uses, were exceeded and remedial actions were necessary to restore beneficial uses (International Joint Commission, 1985). A 43rd AOC was identified in 1991 (i.e. Presque Isle Bay, Erie, Pennsylvania, USA). To address these long-standing beneficial use impairments, the eight Great Lakes states and the Province of Ontario, in cooperation with the federal governments of Canada and the United States, committed in 1985 to developing and implementing a remedial action plan (RAP) to restore beneficial uses in each AOC within their political boundaries. Each RAP had to identify the specific measures necessary to control existing sources of pollution, abate existing contamination (e.g. contaminated sediments), and restore all impaired uses.
The Detroit River, a 45.3-km connecting channel through which the entire upper Great Lakes (i.e. Lakes Superior, Michigan, and Huron) flow to the lower Great Lakes (i.e. Lakes Erie and Ontario), was one of these AOCs (Figure 1). Following the political commitment, the RAP for the Detroit River was initiated in 1986 with the establishment of a team of representatives from the federal, state, and provincial governments (Michigan Department of Natural Resources and Ontario Ministry of the Environment, 1991). Loss of fish and wildlife habitat was one of 11 use impairments identified. The Detroit River RAP noted that a significant loss of fish and wildlife habitat, including a 97% loss in coastal wetlands, occurred as a result of human activities like diking, dredging, construction of bulkheads, and filling (Michigan Department of Natural Resources and Ontario Ministry of the Environment, 1991). This paper will review, from a management perspective, what has been achieved and learned from this 32-year effort to restore fish and wildlife habitat in the Detroit River AOC.
Major initiatives addressing habitat
Historically, habitat management has been a responsibility shared among many agencies and interests with no single oversight. This fragmented responsibility has been an obstacle to realizing ecological improvements and restoration. Through the Detroit River RAP, loss of fish and wildlife habitat was explicitly identified as an impaired beneficial use. This gave focus, clarity, and legitimacy to this issue, and opened up funding from federal, state, provincial, and private sources. There were eight key initiatives over the last 30 years that have championed restoration of fish and wildlife habitat in the Detroit River (Table 1). Early on, efforts focused on quantifying the severity and geographic extent of habitat loss and degradation. Later, scientific assessments were used to review and prioritize potential options and projects. It should be noted that resource management agencies, like Ontario Ministry of Natural Resources and Forestry, Michigan Department of Natural Resources, U.S. Fish and Wildlife Service, Fisheries and Oceans Canada, and Essex Region Conservation Authority (ERCA), and universities, have been actively involved in these initiatives and provided considerable expertise.
Habitat accomplishments and results
Early efforts focused on quantifying the severity and geographic extent of habitat loss and degradation, followed by efforts to set habitat restoration goals and objectives (Michigan Department of Natural Resources and Ontario Ministry of the Environment, 1991). This process took at least 12 years before the first habitat restoration projects were implemented in 1996. Initially, lack of a clear habitat problem definition and scientifically-sound restoration options, and lack of funding, were obstacles to realizing habitat restoration. Then in the late-1990s habitat rehabilitation projects started receiving funding. On the Canadian side, 14 projects were implemented by many DRCC partners, including Environment and Climate Change Canada through the Great Lakes Sustainability Fund, Ontario Ministry of Natural Resources and Forestry through the Canada-Ontario Agreement, ERCA, and others (Table 2). The DRCC is now finalizing a new habitat plan in the spirit of adaptive management, which will identify and prioritize target habitat sites for protection, restoration, and enhancement (Essex Region Conservation Authority, 2012, 2017). Delisting criteria have been identified under the following four categories for this use impairment: aquatic and riparian habitat; shoreline softening; terrestrial habitat; and coastal wetlands. A priority has been placed on creation of habitat historically lost in shallow coastal areas. A decision matrix is being used to rank proposed restoration sites using ecological, practical, and economic factors.
On the U.S. side, Michigan Department of Environmental Quality and its Detroit River Public Advisory Committee were going through a similar process of first reaching agreement on a habitat problem definition (Michigan Department of Natural Resources and Ontario Ministry of the Environment, 1991), including identifying geographic extent, evaluating habitat restoration options, and prioritizing projects (Manny, 2002, 2003; Esman, 2008). Initially, habitat work under the RAP was aspirational. To move beyond aspiration and become pragmatic within fiscal realities, the Detroit River Public Advisory Committee (2014) identified 14 projects that, when completed, would constitute removal of “loss of fish and wildlife habitat” as an impaired beneficial use (Table 3). These diverse projects involve restoration of shoals, nearshore, and wetland habitats, as well as reproductive habitats for birds and fishes. It is important to note that the Great Lakes Restoration Initiative, launched in the U.S. in 2010, has provided over $2 billion basin-wide to accelerate restoration efforts, particularly in AOCs. This clearly helped move from planning to action.
Completing these Detroit River AOC projects and achieving these administrative/management targets will clearly have a positive impact on habitat of the Detroit River. However, more habitat work after delisting will have to be undertaken to reach long-term, ecological goals. One good example of this need is highlighted in a comparison of the 1985 and 2015 georeferenced aerial imagery from the Detroit River that showed that even with the addition of 1.58 km of new soft shoreline and incidental habitat on the U.S. mainland of the Detroit River, there was an overall net loss of 0.74 km of soft shoreline over the 30-year timeframe (Hartig and Bennion, 2016). To reach the “good” state of at least 70% soft shoreline as defined by Pearsall et al. (2012), an additional 12.1 kilometers of soft shoreline will be required on the U.S. mainland of the river in the future. Such ecosystem-based targets will help measure ecological progress and are consistent with the U.S.-Canada Great Lakes Water Quality Agreement. Indeed, researchers have argued for inserting evidence-based management into conservation practice, including quantitative outcome-based monitoring toward clear measurable objectives (Legge, 2015).
Presented below are three examples habitat restoration projects in the Detroit River AOC. These projects illustrate varying degrees of evidence-based, management practice.
Soft shoreline engineering
The Greater Detroit American Heritage River Initiative and others have championed use of soft shoreline engineering – using vegetation and other materials to improve the land-water interface by improving ecological features without compromising the engineered integrity of the shoreline (Caulk et al., 2000; Hartig et al., 2011). Since 1998, a total of 53 soft shoreline engineering projects have been implemented in the Detroit River and western Lake Erie watershed (Hartig, 2014). Of these 53 projects, 49 were undertaken with multiple partners. All were undertaken as demonstration projects that helped attract partners that wanted to learn new techniques and helped demonstrate community benefits. Attracting new partners helped leverage funding.
Most of the soft shoreline engineering projects were undertaken opportunistically through a variety of management tools to enhance/improve riparian or aquatic habitat, including: erosion protection; protection of roads; nonpoint source control; Supplemental Environmental Projects (i.e. a U.S. regulatory tool that implements an environmental improvement project instead of paying fines and penalties to a general fund); contaminated sediment remediation; improvement of waterfront parks; enhancement of private developments; dam removal; “green infrastructure” projects; and greenway trail projects.
Based on the survey of 53 soft shoreline engineering projects, habitat restoration targets and measurable endpoints were lacking. Therefore, greater emphasis should be placed on ensuring a clear, measurable, ecological definition of project success that includes quantifying habitat/ecological targets and objectives that can be used to both evaluate and select appropriate habitat restoration and rehabilitation techniques, and to measure project success (Hartig et al., 2011).
The cost of 53 soft shoreline engineering projects on the U.S. and Canadian sides of the river – more than $24 million USD – underscores the need for adequate assessment of effectiveness. One way of accomplishing this is to incorporate pre- and post-project monitoring of effectiveness into all federal, state, and provincial permits for habitat modification (Hartig et al., 2014). One additional suggestion is to work through partnerships to establish pre- and post-project monitoring to measure project effectiveness (Hartig et al., 2011). This could be laid out in a Memorandum of Understanding or a partnership agreement. Greater effort should be made to involve university students in monitoring through independent studies, theses, and class projects, and to involve environmental and conservation organizations in citizen science to monitor effectiveness. Project leaders should reach out to universities and nongovernmental organizations and inform them of opportunities to participate via monitoring.
Only six of the 53 soft shoreline engineering projects surveyed had quantitative assessment of ecological effectiveness (Hartig et al., 2011). Furthermore, monitoring was only performed for one or two years. Experience has shown that there is a need to perform long-term monitoring to fully document ecological results and allow adjustments to management actions (Hartig et al., 2011). Finally, there is a need for stronger coupling of habitat modification, research, and monitoring. It would be wise to treat such projects as experiments that promote learning, where hypotheses are developed and tested.
Fish spawning reefs
From 1970s through the 1990s no lake sturgeon spawning was reported in the Detroit River (Roseman et al., 2011). Then in 2001, lake sturgeon spawning was documented on a coal cinder pile near Zug Island in the Detroit River for the first time in over 20 years (Caswell et al., 2004). Based on research and monitoring, fishery biologists and managers concluded that lake sturgeon reproduction in the 2000s was now more limited by habitat than environmental quality.
In response, nine fish spawning reefs were constructed in the Detroit River in suitable areas that provided proper conditions and were in close proximity to critical nursery habitats (Table 4). All were successful (Fischer et al., 2018). Two things that stand out in these reef projects are that fishery biologists were the primary champions for the reefs and that these reef projects were treated as experiments and included significant post-project assessment of effectiveness.
Common Tern habitat restoration
One good example of a species that benefits from wildlife habitat restoration is the Common Tern (Sterna hirundo) – a colonial waterbird that has been designated as threatened and a “Species of Greatest Conservation Concern” in Michigan (Eagle et al., 2005). Common Terns have declined in the last three decades across the Great Lakes (Norwood et al., 2011). In the Detroit River there has been a 96% decline over the last 50 years. In the last few decades, Common Tern management has focused on artificial sites, including dredge spoil islands, navigational piers, and breakwaters (Cuthbert et al., 2003).
Most recently, Common Tern nesting habitat was created on Stony Island (2017) and Belle Isle (2008 and 2010). Over 30 Common Terns showed an affinity for the Stoney Island habitat before construction was complete. In 2016, the Detroit Zoo and U.S. Fish and Wildlife Service observed 24 active nests at the Belle Isle habitat. In the late 2000s, Common Tern habitat was enhanced at the two bridges to Grosse Ile and the River Rouge Power Plant. Monitoring documented approximately 200 nesting pairs using the habitat at the Grosse Ile bridges, but none at the Rouge River Power Plant.
A U.S.-Canada roundtable was convened with Common Tern managers and experts to establish an appropriate interim, quantitative target for the number of breeding pairs and their productivity that considers the population ecology of the species (Norwood et al., 2011). Resource managers and researchers agreed that there should be expansion into new colony sites, including possibly Fighting Island, Boblo Island, and Sugar Island piers. The previous five-year mean for the number of breeding pairs was 361 across the region, with a 780 goal by 2020 (Norwood et al., 2011). The interim goal for productivity is to reach at least 1.0 chick per nest across all colonies four out of every five years or a five-year mean of at least 1.0 chick per nest across all colonies. Close coupling of monitoring and management will be required to achieve the Common Tern restoration target.
Conclusions and lessons learned
Over the past 32 years considerable soft shoreline, fish spawning reef, and Common Tern habitat restoration has occurred in and along the Detroit River. Despite this progress, more habitat restoration will be needed to meet long-term ecological goals. To sustain restoration efforts, continuous and vigorous public oversight of shoreline and riparian habitat, and development, will be needed. Key lessons learned include: ensure early involvement of habitat experts in project design; establish quantitative targets for project success; ensure sound multidisciplinary technical support; start with demonstration projects; treat habitat projects as experiments; involve citizen scientists in monitoring; conduct pre- and post-monitoring to measure benefits; communicate and celebrate successes; and promote education and outreach.
Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/uaem.