Summary and Regional Overview
The Grand Traverse Bay (GTB) is located in Lake Michigan, which is part of the Great Lakes of North America, also referred to as the Laurentian Great Lakes (LGL). LGL is in the Eastern North America, spanning both Canada and the United States. The lakes of LGL form the largest freshwater ecosystem in the world, and contain an estimated 20% of global and 84% of North America’s total freshwater (NGS, 2022).
The majority of Michigan and the greater LGL system was molded by the last major glacial episode, known as the late Wisconsinian glacial period. This began roughly 26,000 years ago (26kya) and lasted about 12,000 years, until the period peaked at around 14.5kya and the cooling began to slow. Glaciers rapidly retreated into mountain cirques, until a later resurgence between 13kya-11kya reshaped much of the terrain around the LGL system and Michigan basin (Martin, 1957. Fidler, 2015. Pratt, 2022).
The subsurface geography of the LGL region is vast and complex, and many of the islands in the region are crests of underwater ridges carved by glacial movement. Much of the above-surface landforms are part of a continuous topography that extends underwater (NGDC, 1996). For example, the GTB area contains submerged river deltas that once carried glacial outflow, as well as hidden basins and terraces from ancient glacial lakes. During glacial movement, some areas of Devonian carbonate bedrock were carved in ways that expose softer shale and redbed deposits; these are common geological features in the GTB, and they are highly susceptible to erosion and chemical corrosion (Shoemaker, 1999).
The various water systems that feed into GTB are currently threatened and impacted by a multitude of stressors. Climate change exerts multiple impacts on GTB, with some of the most significant of these being warming of waters, erosion of shoreline, and watershed sediments and stronger winds that damage lake water quality and bring heavier storms (Geiger et al. 2022). Increasing rates of sedimentation due to climate change has led to increases (in severity and frequency) in damages to softer shale and rockbed deposits. Additionally, invasive species, such as phragmites, sea lamprey, carp and round goby impact ecosystem dynamics and threaten the biodiversity in the GTB region (Michigan-a, n.d.). Furthermore, agricultural development over the last few decades has had mounting impacts on water quality in surrounding freshwater systems, consequently harming the health of wildlife in and around GTB and resulting in pollutants in and disruptions to ecosystem functions (Hyndman, 2001; Wayland, 2001).
For further information about the GTB and efforts to improve the health of the local watershed, visit The Watershed Center of Grand Traverse Bay website (www.gtbay.org).
Indigenous history and agriculture
The GTB region is in the territory of the Indigenous peoples of the Three Fires Confederacy, consisting of the Odawa (Ottawa), the Ojibwa (Chippewa) and the Bodowadomi (Pottawatami) peoples. Oral histories explain how these peoples voyaged to find a place where food grows on water, and in GTB, they found wild rice growing afloat. After this journey (what is sometimes referred to as the Great Migration), the communities of the Anishinaabek Nation found home in the GTB region, living in the region for hundreds of years before Europeans encountered them (Hele, 2020).
Historically, Indigenous peoples settling around the great lakes areas had traded as far west as the rocky mountains for thousands of years. The traveling routes and cultural practices of the Three Fires Confederacy were quickly integrated, and Lake Michigan provided an excellent water highway thanks to canoes, allowing for transportation of greater quantities, and heavier items (Clifton et al. 1986). Traditional foods of the Three Fires Confederacy are classed as foods cultivated before the influence of Europeans and Americans, such as squash, beans, corn and the highly prized wild rice, and maple sugar. Cultural foods are classed as foods created later, after the introduction of ingredients from foreign cultures, like shortening and wheat-flour. These foods include Indian tacos and fry-bread, as well as canned goods, much of which contributed to the evolution of the reservation diet, which in turn many believe is the foundation of the epidemic of obesity and diabetes amongst many Indigenous peoples reserves (Mailer, 2013. Sander, 2016).
After European settlement, two wars were fought on Anishinaabek land: one between the English and French, and another between the English and the Americans. In 1837, following the second of these wars, the American government brought a treaty to the First Peoples, which resulted in the establishment of two thirds of the current state of Michigan. In 1855, the remaining third was claimed through another treaty. The treaty processes and outcomes have been problematic and highly impactful to the Indigenous communities, and through a series of political loopholes and unlawful measures, the First Peoples were forced to re-purchase their land and remain on small land reserves. In 1980, the tribe was re-recognized as the Grand Traverse Band of Ottawa and
Chippewa Indians, and granted rights of government (GTB & Anishinabek 2022). In 2022, the Anishinabek Nation Governance Agreement Act, which is a self-government agreement, received Royal Assent from Canada (UOI, & PoC 2022.)
Intercropping and agroforestry are agricultural management techniques practiced by Indigenous populations thousands of years ago. In the modern era, these techniques largely remain the foundation of agriculture, though the priority of permaculture has somewhat declined (Heim, 2020). Native food sovereignty is a pillar of health, cultural recognition and economic strength for the Three Fires Peoples. In 2016, the Ojibway Growers were granted funds to practice organic, traditional farming with native seeds to test for larger scale crop growth and re-establish Indigenous varieties of foods. The project was a success, with the cultivation of Jerusalem artichokes, heritage potato, squash and bean varieties, hog peanuts, juneberries, chokecherries, edible and medicinal herb varieties and bergamot, milkweed and pollinator habitats. As a result, food imports to Indigenous communities in reserve areas have decreased, lost food varieties have been reintroduced into diets, and economic strength has increased due to profits gained from excess harvest (Paige & Tieken, 2016).
GTB is in Michigan, located in the north-eastern region of Lake Michigan, and it covers an area of 277 mi2. Traverse City is situated on the southern coast of the bay, and the city is known as the cherry capital of the world. GTB is split into two arms, east and west, divided by the Old Mission Peninsula. Figure 1 presents a map of the GTB and the smaller bays and harbours it contains.
Figure 1: A Google Earth captured map of the study site, along with notable locations around GTB. There are 5 smaller bays, 4 on the west arm of the bay, and one on the right. The right arm also contains the deepest region of the bay, with a maximum depth of 590 ft. (TWC. & NOAA, 2022). Data sources: Google Earth, Image Landsat / Copernicus, NOAA.
GTB is bounded by 132 miles of shoreline, on which a multitude of waterfront communities are located. Local residents enjoy the natural scenery and beauty, and consider it to be a significant factor in their decisions to settle in GTB and call it home. Due to its natural beauty and aquatic environment, tourism and aquaculture are significant components of the local economy in the GTB region (Pijanowski et al., 2001; Hyndman, 2016; TWC, 2022).
GTB is one of the few oligotrophic bays in the LGL system, and it provides critical freshwater resources (Boutt, 1999). Management of groundwater, water storage, water and watershed quality, fishing, industrial water use and runoff, and water recreation are all closely monitored by both the local government, as well as the tribal councils of local Indigenous communities (Kelly, 1987). In a report from 2003, it was noted that water quality of the GTB area and tributaries is good, but with some habitat diversity threats due to sedimentation rates (U’ren, 2005).
Watersheds and Freshwater systems
GTB is comprised of nine watershed systems, collectively known as the Grand Traverse Bay (GTB) Watershed, with a total area of 976mi2. The two largest subwatersheds are the Elk River Chain of Lakes (ERCoL) with an area of 503mi2 and the Boardman River subwatershed with an area of 284mi2. The other subwatersheds (Figure 2) are The West Bay shoreline and tributaries (68mi2), the East Bay shoreline and tributaries (39mi2), the Old Mission Peninsula (31mi2), Mitchell Creek (16mi2), Ptobego Creek (14mi2), Acme Creek (13mi2), and Yuba Creek (8mi2) (U’Ren, 2005). The total watershed system collects 220 billion gallons of water annually. Approximately 60% of this volume is from tributary rivers, 35% from direct precipitation, and 5% from groundwater, with this latter source originating almost entirely from underground glacial deposits (Cummings et al. 1990. TWC, 2022).
Figure 2: Subwatersheds of the Grand Traverse Region (GTR). Political boundary lines are also noted for county differentiation; we can see that the shorelines of GTB lie in Leelanau county, Grand Traverse county and Antrim county. Image credit: Watershed Protection Plan (U’Ren, 2005).
The ERCoLis located east of GTB, mainly in Antrim county (see Figures 1 and 2). It is comparable but larger in area than the GTB, having 200 miles of shoreline and over 60mi2 of water surface area, and it provides roughly 60% of GTB’s surface water input (U’Ren, 2005). Reports show this watershed to have some of the nation’s highest water quality, but are facing the same threats as many other water bodies in the GTB region, that is, “land development pressures, invasive species, failing septic systems and barriers to hydrological connectivity” (Silver et al., 2016).
The main river draining the GTB Watershed is the Boardman River, which originates from the interior of Grand Traverse County (GTC) and drains Spider Lake and other water bodies located southeast from Traverse City. The Boardman river travels west and then north through Traverse City, flowing into the west arm of GTB and discharging an average 294ft3. The Boardman watershed drains around 183,000 acres of land into GTB, and provides roughly 30% of the bay’s surface water input (USGS, 2016. GTCD, 2022).
Potential and existing disruptions to water security
A warmer climate with a high moisture content results in increased precipitation and extreme precipitation events (EPA-b, 2021). This leads to flooding, which is exacerbated by inadequate storm water management systems, disruption of wetlands due to a higher water table, and increased erosion on inland sediment systems (Geiger et al., 2022). In addition, due to the size of the LGL system (and Lake Michigan in particular), warming waters have consistent year-round effects on the temperature of surrounding regions. Water has strong insulating properties, which means Michigan and the GTB region are experiencing hotter summers and milder winters, which has negative effects on native wildlife and plant species (EPA-a, 2021).
Finally, over-sedimentation issues are a serious threat, stemming from increased precipitation in GTB watersheds and turbidity in waterways and shorelines. The fragility of the system thanks to urban expansion means the sediments are vulnerable to erosion, leading to a higher density of sediments suspended in the water (Roush, 2012). Examples of suspended sediment threats are the suffocation of fish eggs as sediments settle on spawning zones, as well as the stunting of aquatic plant and bacteria growth due to cloudy waters blocking/reducing sunlight penetration into subsurface spaces (LJEA, 2018. GoC, 2022). Tourism and aquaculture (which are foundational for the area’s economy and linked to local ecosystem health) are also threatened by these types of climate change issues and watershed degradation (Pijanowski et al., 2001; Hyndman, 2016; TWC, 2022).
Damaging Land Use Re-Designations
The GTB area has seen rapid urban expansion in the southern peninsula since the 1970s. This has led to increased urbanization and human activity near the east and west bay shores (Pijanowski et al., 2001; Britannica, 2011). The local agricultural sector and agricultural expansion have also grown rapidly in the area.
Land use and land systems changes result in reshaping of surface and subsurface terrains, as well as changes in the permeability and erodibility of terrain. These changes have ecological impacts on areas of high biodiversity. Changing surface and groundwater hydrodynamics, in extreme cases, can result in drainage of slow-filling aquifers or (in other areas) flooding of soils and root systems. The effects of such changes include variations in temperature or moisture, food profusion and chemical balance from what normally occurs in the local habitats, and these ecological stressors are often compounded by other issues, such as fertilizer and pesticide pollution (Boutt, 1999; Pijanowski et al., 2001; Ganju et al., 2016; Stark et al., 2017). The majority of these effects have begun to make themselves apparent as of the last decade.
Agricultural development can exert significant effects on minerals and nutrients cycling in nearby water systems (McKague et al., 2005; Hess, 2019). With the rapid expansion of the agricultural industry in the GTC over the last few decades, nutrient pollutants (i.e., nitrogen and phosphorous) are being discharged into freshwater systems that feed the bay. Additionally, the runoff from urbanized zones and damaged sedimentary environments contains contaminants such as waste, toxic industrial and agricultural chemicals, and more (Goodwin & Smith, 2022). As a consequence, the GTB is suffering a reduction in water quality (Wayland, 2001).
Chemical overload in the water has long lasting damaging effects on waterborne wildlife such as fish, submerged flora and natural bacterium that help to reduce the presence of toxic plants (USGS, 2018). Additionally, high levels of nutrient pollutants can lead to eutrophication, algae blooms, and ultimately reductions in oxygen in aquatic ecosystems (hypoxia). The result is often ‘dead zones’ in water systems, and this issue is particularly a concern for oligotrophic lakes such as GTB (USGS, 2018. EPA 2022).
An algae bloom of cyanobacteria formed in Lake Erie in summer 2014. On August 2nd of that year, half a million people were told to avoid local drinking water due the presence of cyanobacteria toxins that cause rashes, respiratory issues and flu-like symptoms. Cyanobacteria blooms are mainly attributed to agricultural runoff entering and overloading water systems, combined with septic runoff and sewage and catalyzed by higher temperatures in summer. Climate change raising average water temperatures and the expansion of agriculture around north-eastern Lake Michigan is a recipe for the same issues that were faced in Lake Erie in 2014, and continue to cost residents of the area additional resources to manage (Frankel, 2014. Graham, 2022. Quirk, 2022).
Non-native species in GTB are abundant, but only a few of these species areconsidered invasive with respect to their ecological impacts. Pacific Salmon for instance is a prize catch, but they mainly feed on alewives, an invasive species that impacts native fish (Gillies, 2009). Other invasive waterborne wildlife species include round goby, sea lamprey, and various asian carp species. Round goby are bottom feeder fish that compete with other native fish, such as the culturally significant whitefish, and also target spawn as a food source. Impacts from the round goby activity include decline in sports fishing species, such as bass. Sea lamprey are a parasitic fish that target larger fish, notably predator fish species. Declines in predator species results in the exponential growth of less desirable small-fish populations, like round goby, which can overwhelm other aspects of the local ecosystem (Michigan-a, n.d.).
Asian carp species feed voraciously and can wreak havoc on delicate ecosystems. There is a risk of black and bighead carp being introduced into GTB from the Illinois River, which would pose a threat to Michigan’s native mussel population, many of which are endangered (Michigan-b, n.d.). Bighead carp can eat up to 40% of their body weight each day, and this feeding behaviour could significantly strain the plankton populations of Lake Michigan (Michigan-c, n.d).
Invasive landborne species include Phragmites, spotted knapweed and more. Phragmites are a prolifically-growing block-style plant, which can grow up to 14 feet high. The dense growth formation and height of the plant crowds out other flora, impacts natural scenery and aesthetics, and destroys habitats (GLPC, 2009). Spotted knapweed has been a dilemma for Michigan for over a century, growing prolifically due to its huge seed stores, up to 140,000 seeds per m2. The plant also releases chemicals that displace vegetation and hinder root growth, effectively claiming land as it creeps across the environment (NCC, N.D).
Current initiatives and efforts
An auditory carp deterrent device is being tested by the USGS to help protect native ecosystems from voracious asian carp species by providing areas of refuge for native aquaculture.
The International Joint Commission of the Great Lakes is looking for input on procedures to restore, maintain and protect the water quality of the combined freshwater systems.
Urban tree canopy restoration has been an ongoing project designed to reduce temperature buildup in the urban core, and provide mitigation of stormwater overflow via natural absorption.
Watershed and climate management plans lay the groundwork for sustainable projects such as:
- Conservation and restoration of wetlands to increase carbon
- Restore waterways and implement parks to connect habitats in remote and urban
- Consultation with tribal nations to produce sustainable environmental management practices, with recognition of treaty rights and
- Establishing a $5M Energy Efficiency and Green Revolving Fund to expand renewable energy and energy efficient projects at state facilities.
- Electrifying the state’s vehicle fleet, and providing widely accessible electric vehicle charging stations.
- Launching education campaigns and programs around sustainability, and providing funding for sustainability related post-secondary pursuits.
- Launching the nation’s first carbon sequestration and market program on forested land.
Imperatives for Grand Traverse Bay include maintaining good-to-exceptional water quality, and preparing for impending changes brought by climate change. In addition, management of agricultural expansion and non-native species populations will help protect the diversity of habitats in the GTB region. To that end, the state of Michigan, Grand Traverse county and related organizations have a series of strategies and plans:
Michigan’s Department of Environment, Great Lakes and Energy Healthy Climate Plan takes into account economic stability, environmental fortitude and social readiness for climate change. The objectives of the plan include a campaign for green energy production, addressing environmental injustices, protection of natural resources, wildlife and conservation efforts. An overarching goal to provide an example of safe, sustainable management is outlined with details of achieving carbon neutrality by 2050.
The Grand Traverse Band of Ottawa and Chippewa Indians seeks to remediate loss of food diversity, and protect the territories on which the Three Fires Confederacy of peoples settled. To this end, native farming practices rejuvenate lost species of crops, and with the assistance of the EPA, are working to integrate clean water acts that will control pollution of water systems. Additionally,
The Watershed Center 2021-2023 strategic plan was created to direct associations and organizations with assisting relevant government entities in management of the Grand Traverse Region Watershed. The goals of which are: maintaining water quality, biodiversity, health of soils and raising awareness of environmental issues through a sustainability campaign, provision of technical reports and advice, and education about agricultural and urban pollutants that can affect local water supplies.
The Watershed Center watershed protection plan was released in 2005, and updated in 2021, providing an evaluation of the region in every aspect. Water quality, biodiversity, critical systems, threats to stability, as well as recommendations for future protections, a plan for education and outreach, and finally a criterion for measuring maintenance of water quality. This framework provides a foundation on which to implement sustainable projects designed to fortify the environment of GTB.