Detroit River Research Articles

Occurrence, habitat, and movements of the endangered northern madtom (Noturus stigmosus) in the Detroit River, 2003–2011

The northern madtom (Noturus stigmosus or NOM) is a small catfish, native to North America. It is globally vulnerable and endangered in Canada, Ontario, and Michigan. In 1994 and 1996, it was found in the St. Clair River and in Lake St. Clair, respectively. However, it had not been found downstream in the Detroit River since 1978. We report catches of 304 NOM from 2003 to 2011 and describe their mud and sand habitats in the deep (10m), dark, Detroit River. We found adult NOM, including 3 ripe males (90–107mm SL) in head waters of the river near Belle Isle in Michigan waters, and both adult and 4 juvenile NOM (21–30mm SL) near Peche Island in Ontario waters. From 2009 to 2011, in the river's middle reach, we caught 7 adult NOM for the first time near Fighting Island in Ontario waters, but no NOM in the river's lower reach. Our mark–recapture results showed that within 6weeks, 2 adult NOM moved east 2.0km from Michigan waters near Belle Isle across the deep (10m) Fleming Channel of the Detroit River to Canadian waters near Peche Island. Analysis of annuli from pectoral spines of 7 dead NOM revealed that they live to at least 6years of age in the Detroit River. This is the first age data that we could find for a NOM population. Our findings extended our knowledge of habitat, reproductive ecology, age, and distribution of NOM in the Detroit River corridor.

A model to locate potential areas for lake sturgeon spawning habitat construction in the St. Clair–Detroit River System

In response to a need for objective scientific information that could be used to help remediate loss of fish spawning habitat in the St. Clair River and Detroit River International Areas of Concern, this paper summarizes a large-scale geographic mapping investigation. Our study integrates data on two variables that many riverine fishes respond to in selecting where to spawn in these waters (water flow velocity and water depth) with available maps of the St. Clair–Detroit River System (SC–DRS). Our objectives were to locate and map these two physical components of fish habitat in the St. Clair and Detroit rivers and Lake St. Clair using a geographic information system (GIS) and to identify where, theoretically, fish spawning habitat could be remediated in these rivers. The target fish species to which this model applies is lake sturgeon (Acipenser fulvescens), but spawning reefs constructed for lake sturgeon in this system have been used for spawning by 17 species of fish. Our analysis revealed areas in each river that possessed suitable water velocity and depth for fish spawning and therefore could theoretically be remediated by the addition of rock-rubble substrate like that used at two previously remediated sites in the Detroit River at Belle Isle and Fighting Island. Results of our analysis revealed that only 3% of the total area of the SC–DRS possesses the necessary combination of water depth and high flow velocity to be indicated by the model as potential spawning habitat for lake sturgeon.

A description of the nearshore fish communities in the Huron–Erie Corridor using multiple gear types

Great Lakes coastal wetlands provide a critical habitat for many fish species throughout their life cycles. Once home to one of the largest wetland complexes in the Great Lakes, coastal wetlands in the Huron–Erie Corridor (HEC) have decreased dramatically since the early 1900s. We characterized the nearshore fish communities at three different wetland complexes in the HEC using electrofishing, seines, and fyke nets. Species richness was highest in the Detroit River (63), followed by the St. Clair Delta (56), and Western Lake Erie (47). The nearshore fish communities in the Detroit River and St. Clair Delta consisted primarily of shiners, bluntnose minnow, centrarchids, and brook silverside, while the Western Lake Erie sites consisted of high proportions of non-native taxa including common carp, gizzard shad, goldfish, and white perch. Species richness estimates using individual-based rarefaction curves were higher when using electrofishing data compared to fyke nets or seine hauls at each wetland. Twelve fish species were captured exclusively during electrofishing assessments, while one species was captured exclusively in fyke nets, and none exclusively during seine hauls. Western Lake Erie wetlands were more indicative of degraded systems with lower species richness, lower proportion of turbidity intolerant species, and increased abundance of non-native taxa. This work highlights the importance of coastal wetlands in the HEC by capturing 69 different fish species utilizing these wetlands to fulfill life history requirements and provides insight when selecting gears to sample nearshore littoral areas.

An ecological basis for future fish habitat restoration efforts in the Huron-Erie Corridor

This perspective describes the major natural and anthropogenic forces driving change in the abundance and quality of fish habitats in the Huron-Erie Corridor (HEC), the Great Lakes connecting channel comprised of the St. Clair River, the Lake St. Clair, and the Detroit River. Channels connecting the Laurentian Great Lakes discharge large volumes of water equal to or greater than most other large rivers in the world that is of consistent high quality and volume, all year. Owing to creation of the St. Lawrence Seaway through the Great Lakes, the connecting channels have been modified by dredging over 200km of deep-draft shipping lanes with a maintained depth of no less than 8.2m. Combined with modification of their shorelines for housing and industries, use of the connecting channels for discharges of industrial and municipal wastes and shipping has resulted in numerous beneficial use impairments, such as restrictions on fish and wildlife consumption, degradation of fish and wildlife populations, and losses of fish and wildlife habitat. Various options for remediation of native fish populations and their habitats in the Great Lakes connecting channels, including construction of spawning habitat for threatened and high-value food fishes, such as lake sturgeon (Acipenser fulvescens), walleye (Sander vitreus), and lake whitefish (Coregonus clupeaformis), have been implemented successfully in two of the channels, and form the basis for further recommended research described in this article.

Synthesizing reference conditions for highly degraded areas through best professional judgment

Reference sites, comparable in physical and chemical characteristics to test sites with the exception of the effect of interest, provide a set of species to contrast against test site data and assign a condition to test sites in the Reference Condition Approach. However, what if disturbance is ubiquitous and comparable reference sites are absent? Here, we use the Detroit River as a case study where development and industrialization has rendered reference sites absent. In this paper, a novel application of best professional judgment was developed to generate a set of species characteristic of reference conditions. The synthesized assemblage functions as substitute to a sampled reference site and can be applied analogously towards determining condition and assessing recovery. Members of the Huron–Erie Corridor Steering Committee, comprised of agency partners that manage the corridor, were surveyed to produce a hypothetical data matrix of the fishes present in the river in the absence of anthropogenic disturbance. The synthesized assemblages were assessed using an Index of Biotic Integrity and subsequently integrated into a Principal Coordinates Analysis with test site fish assemblage data. Recovery and response to remediation was determined by the position of the test sites within confidence ellipses. The results indicated signs of recovery in upstream sites of the Detroit River, but no recovery at downstream sites. The application of the best professional judgment approach towards reference conditions provides a novel and versatile method to interpret species assemblage change and allows practitioners the ability to select specific assemblages coincident with restoration objectives.

A Landscape of Ruin and Repair: Parks, Potatoes, and Detroit's Environmental Past, 1879–1900

The Michigan Historical Review 40:1 (Spring 2014): 49-72©2014 Central Michigan University. ISSN 0890-1686 All Rights Reserved A Landscape of Ruin and Repair: Parks, Potatoes, and Detroit’s Environmental Past, 1879-1900 By Joseph Stanhope Cialdella During the last decades of the nineteenth century, Detroit was in a state of disarray. Air quality was poor, and the smells of the city were less than inviting. City reports and newspapers recorded numerous complaints, from the filthy conditions at the Eastern Market and the muddy streets, standing water, and sinkholes on the Eastside near Bloody Run Creek, to the unsanitary and abandoned buildings on Michigan Avenue and Fort Street.1 Most of the city’s effluence found its way to the Detroit River, because, as census worker J.C. Holmes noted in 1880, “The natural drainage of Detroit is not very good, and is by no means depended on for the drainage of the city.” 2 In addition to these environmental concerns, tensions between residents of the city festered as they tangled over issues of immigration, unemployment and population growth. In just ten years the city’s population nearly doubled from 116,000 in 1880 to 205,000 in 1890, with nearly a quarter of the residents (over 45,000) listed as “foreign-born.”3 Like many American cities during this period, Detroit was defined by the characteristic demographic, economic, and environmental transformations of a growing industrial center that created a landscape of seemingly perpetual ruin and repair.4 1 For example of complaints regarding environmental conditions in the city, see Journal of the Common Council of the City of Detroit, 1894-95 (Detroit: Allied Printing, 1895), 1300. The Detroit Evening News was dismayed to find abandoned and neglected buildings after a recent tour of the area. “Fort Street West,” Detroit Evening News, April 1, 1894. 2 U.S. Census Bureau, Tenth Census of the United States, 1880 (New York, NY: Norman Ross Publishing, 1991), 605-09. 3 Michigan Department of State, Census of the State of Michigan, 1894, Vol. I (Lansing, MI: R. Smith and Company, 1896), 216-227. 4 In his work, Another City (New Haven: Yale University Press, 2008), architectural historian Dell Upton refers to late eighteenth and nineteenth century American urban centers as “cities of perpetual ruin and repair” (pp. 19-40). In this essay, I use the terminology to think about the meaning of Detroit’s burgeoning industrial landscape. 50 The Michigan Historical Review Amidst this chaotic urban development, city leaders imagined ways they might transform Detroit into not just a manufacturing hub but also a place with the order and prestige of a great metropolis. There were many political, economic, and social ideas that individuals, civic organizations, and the municipal government employed to meet the challenges of reconciling human life with urban expansion. Among these choices, leaders in Detroit also wondered: Could parks and gardens serve as necessary tools to mend this broken landscape, achieve social cohesion, and meet their own expectations about Detroit’s future? Among the defining features of Detroit’s past, parks and gardens are generally not the first of these ideas that come to mind. Compelling histories of the automobile and other technological transformations, industrialization, race relations, and, more recently, a place and a people devastated by the policies of urban disinvestment, have instead come to define the city’s history. However, connected to these better-known stories of Detroit’s past is an urban environmental ethic where the role of parks and gardens helped make Detroit a modern city of national significance. The growing City Beautiful movement, with its ethos of visual order and neoclassical design, National Parks, and an environmentalism caught between notions of preservation and conservation, were spreading across the United States during this period; in Detroit, city and civic leaders, planners, and everyday residents increasingly recognized the value and power of the environment in which they lived. As they debated ways to reshape and reuse the city’s landscape, Detroiters developed strands of a nascent urban environmentalism, which they used to invent and test ideas about how human relationship with nature would function in an industrial setting. In particular, the development and construction of two...

“Muskrat French”: Origins of a Culture, a Language, and a People

“Muskrat French”: Origins of a Culture, a Language, and a People by James LaForest Nearly every year, usually in late winter or early spring, the media pick up on a story about a Detroit River region culinary tradition: the eating of muskrat as a Lenten custom. Generally the stories focus on the area of Monroe (part of an area known as Frenchtown) and other downriver Detroit communities that observe the custom. The tradition is explained in two ways: either that the early French Canadian trappers lived off muskrat, learning from the Indians that it was edible, or that Father Gabriel Richard, pastor of St. Anne’s parish in Detroit from 1802-1832, granted a special dispensation to the local habitants to eat muskrat during Lent. The media stories then continue with a description of the meal itself, the taste of the meat, and assurances that it is both safe and legal.1 Historians of the Detroit River region have provided more in-depth research on the topic. Ralph Naveaux, former director of the Monroe County Historical Museums and member of the Michigan Commission for the Bicentennial of the War of 1812, described the eating of muskrat in the context of a much broader regional French Canadian cuisine that emanated from the métis (mixed aboriginal American and European French) culture of the fur trade areas.2 Dennis Au, Historic Preservation Officer of the city of Evansville, Indiana, has also written extensively on Michigan’s French Canadian culture. According to Au, it was media coverage of the annual muskrat dinners in 1988 that precipitated a ban on the public sale of muskrat meat once it reached officials at the Archdiocese of Detroit and the Department of Agriculture. The Archbishop, appalled by the thought of muskrat as meat, declared the 1 John Holusha, “Wyandotte Journal; Where the Muskrat is a Delicacy for Lent,” New York Times, April 1, 1988; “What’s for Dinner? In Michigan, it’s Muskrat,” USA Today, March 1, 2013; “Muskrat Love: A Lenten Friday Night for Some Michiganders,” Catholic News Service, March 8, 2007; “You Haven’t Lived Here Until . . . You Eat Muskrat,” Detroit Free Press, November 25, 2012. 2 Ralph Naveaux, “Remnants of ‘Mushrat French’ Cuisine in Monroe County, Michigan,” Repast (Spring 2007): 3-6. THE MICHIGAN HISTORICAL REVIEW 40:2 (FALL 2014): 87-100 @ 2014 Central Michigan University. ISSN 0890-1686 All Rights Reserved 88 The Michigan Historical Review legendary dispensation void. What followed these actions was a groundswell of support for the local custom and ultimately a reversal of the decisions. 3 These Lenten muskrat dinners are part of a much broader regional culture, the “Muskrat French,” also known as “Mushrat French.” This term, as Marcel Beneteau notes, refers both to a living culture and to the French dialect that was widespread in the area from the eighteenth century onward and is still spoken in areas around Lake St. Clair.4 Though these accounts point to who the Muskrat French were (Detroit River region French Canadians), it is less established when this term came into being, and why, and how it has been used over time. They forged a unique regional culture better understood by its origins, development, and experience rather than by just one element of its cuisine, albeit unique. In order to better understand the development of the term “Muskrat French” and their culture, it is necessary to examine how the early French Canadians of Detroit and the Pays d’en Haut (Great Lakes Upper Country) were viewed by the British and Anglo American officials who began dominating the region in the late eighteenth century. In 1764 British General Thomas Gage referred to the French of Detroit as “a People . . . as wild as the Country they go in, or the (Indian) People they deal with, and are far more vicious and wicked.” He wrote that the French were “vagabonds” and “a terrible set of people who stick at nothing true or false . . . roving in the Desarts [sic] and seating themselves among the Indians,” living with “different Tribes, moving from one to another as fancy leads them.”5 Another opinion of Detroit’s French populace comes from the journals of Jonathan Carver, a Massachusetts...

Use of main channel and two backwater habitats by larval fishes in the Detroit River

Recent investigations in the Detroit River have revealed renewed spawning activity by several important fishes, but little is known about their early life history requirements. We surveyed two main channel and two backwater areas in the lower Detroit River weekly from May to July 2007 to assess habitat use by larval fishes. Backwater areas included a soft-sediment embayment (FI) and a hard-sediment area (HIW). Main channel sites were located adjacent to each backwater area. Water temperature, velocity and clarity measurements and zooplankton samples were collected weekly. A macrophyte assessment was conducted in July. Growth and diet of larval yellow perch (Perca flavescens), bluegill (Lepomis macrochirus) and round goby (Neogobius melanostomus) were used to assess habitat quality. Macrophyte diversity and percent cover were higher and velocity lower at FI than HIW. Although larval fish diversity was highest in the main channel, yellow perch and bluegill larvae only grew beyond the yolk stage at FI, where they preferentially selected copepods, while Daphnia were selected in the main channel. Round goby ate harpacticoid copepods and Daphnia and grew at similar rates in HIW and the main channel. These data indicate that FI was a valuable nursery area for yellow perch and bluegill, whereas HIW was better suited to round goby. We only assessed two backwater areas, thus a complete census of wetland areas in the Detroit River is needed to identify valuable habitats. Restoration of shallow backwater areas is essential for rehabilitating fish populations and should be a priority in the Detroit River.

Diet and habitat use by age-0 deepwater sculpins in northern Lake Huron, Michigan and the Detroit River

Deepwater sculpins (Myoxocephalus thompsonii) are an important link in deepwater benthic foodwebs of the Great Lakes. Little information exists about deepwater sculpin spawning habits and early life history ecology due to difficulty in sampling deep offshore habitats. Larval and age-0 deepwater sculpins collected in northern Lake Huron and the Detroit River during 2007 were used to improve our understanding of their habitat use, diet, age, and growth. Peak larval density reached 8.4/1000m3 in the Detroit River during April and was higher than that in Lake Huron. Offshore bottom trawls at DeTour and Hammond Bay first collected benthic age-0 deepwater sculpins in early September when fish were ≥25mm TL. Otolith analysis revealed that hatch dates for pelagic larvae occurred during late March and larvae remained pelagic for 40 to 60days. Diet of pelagic larvae (10–21mm TL) was dominated by calanoid copepods at all sample locations. Diets of benthic age-0 fish varied by location and depth: Mysis and chironomids were prevalent in fish from Hammond Bay and the 91m site at DeTour, but only chironomids were found in fish from the 37m DeTour site. This work showed that nearshore epilimnetic sites were important for pelagic larvae and an ontogenetic shift from pelagic planktivore to benthivore occurred at about 25mm TL in late summer. Age analysis showed that larvae remained pelagic long enough to be transported through the St. Clair–Detroit River system, Lake Erie, and the Niagara River, potentially contributing to populations in Lake Ontario.

Fate and mass balances of triclosan (TCS), tetrabromobisphenol A (TBBPA) and tribromobisphenol A (tri-BBPA) during the municipal wastewater treatment process

Municipal wastewater treatment plants (MWTPs) are impacted by down-the-drain influents of anthropogenic chemicals. These chemicals are in consumer products and include the flame retardant tetrabromobisphenol A (TBBPA) and antimicrobial triclosan (TCS). Characterization of the distribution of TBBPA, TCS and the TBBPA product tribromobisphenol A (tri-BBPA) was determined at five stages along the treatment process of a typical Canadian MWTP facility. Overall, the TCS concentrations for both liquid (influents, primary effluents and final effluents (FEs)) and solid samples (primary and waste activated sludges) were similar to reported ranges in the literature. In contrast to TCS, both TBBPA and tri-BBPA concentrations were scarcely available in the literature. The TBBPA concentrations were within literature ranges for both influents and sludges, while the tri-BBPA sludge concentrations were markedly higher than a single available previous study. Mass balances for TCS, TBBPA and tri-BBPA indicated 7, 9 and 42%, respectively, of each chemical remaining in the FEs. The resultant annual mass loadings into the Detroit River were estimated to be 3.3 kg, 6.57 g, and 21.5 g for TCS, TBBPA and tri-BBPA, respectively.

Assessment of decadal changes in sediment contamination in a large connecting channel (Detroit River, North America)

Concentrations of selected heavy metals (Cd, Cu, Hg, Pb, Zn) and organic contaminants (PCBs, PAHs) were investigated in samples from the Detroit River (Great Lakes, North America) in 1999 and 2008/09 collected using a stratified random sampling design. Getis–Ord geospatial analysis was used to further establish locations of areas demonstrating significantly high and low contaminant concentrations in the river. Based on the stratified random sampling design, a majority of the examined metals and organic contaminants demonstrated little or no trends with respect to regional sediment concentrations and river-wide mass balances over the investigated time interval. The Getis–Ord analysis revealed local scales of contaminated and clean areas which did not conform to the original strata used in the geostatistical sampling design. It is suggested that geospatial analyses such as Getis–Ord be used in the design of future sediment quality surveys to refine locations of strata that can simultaneously address sediment recovery over system-wide, regional and local spatial scales.

Effects of water clarity on the length and abundance of age-0 yellow perch in the Western Basin of Lake Erie

Water clarity is an important environmental variable that may affect fish populations by altering the visual environment. Effects can change feeding ability, as well as alter predation risk. The western basin of Lake Erie provides a valuable model system for studying the effects of transparency because the two main tributaries, the Maumee and Detroit rivers, differ substantially in clarity. We used Generalized Additive Models (GAMs) to quantify the relationship between transparency and the observed abundance and length of age-0 yellow perch (Perca flavescens) in August, based on surveys from 1986 to 2006. Secchi data from June to August were included in the models that best explained the variation in yellow perch abundance and length. August values for bottom oxygen and bottom temperature also increased model fit for abundance, whereas only bottom temperature improved model fit for length. Our models indicate that transparency was positively related to the August length while abundance of age-0 yellow perch was inversely related to transparency. Highest abundance was observed in areas with the lowest transparency, with peak abundances observed in areas with less than 1m of Secchi depth. This is in contrast to August length, which increased as transparency increased, to an asymptote at around 3m of Secchi depth. The split nature of water clarity conditions in the western basin of Lake Erie has resulted in areas with higher growth potential, versus areas with higher apparent survival.

On the Boundary: Local Authorities, Intergovernmental Relations and the Governance of Border Infrastructure in the Detroit–Windsor Region

A growing and diverse academic literature exists on the functional, cultural and political linkages between border communities. These examinations of borderland communities seek to explain why and how linkages develop and assess the strength and implications of these relationships. In North America, Detroit–Windsor is the quintessential metropolitan border region along the Canada–US border. It is a community that shares many problems and policy concerns as well as strong functional linkages. One of these concerns is the reform of the Detroit River border crossing. This is the busiest land border crossing in North America and it is central to the regional economy as well as the wider North American economy. Over the past decade, the senior governments have debated reform of border infrastructure and the access routes to planned and existing crossings. One of the central considerations in this set of reforms has been the construction of a new crossing to reduce waiting times and increase infrastructural redundancy at this key choke point. Any new crossing will have a major impact on the local communities and various local actors on both sides of the border have sought to participate in the policy debate and influence the decision-making process. This article examines the extent to which local actors in Detroit and Windsor have interacted and sought to co-ordinate their policy positions and strategies within the border reform debate. The article focuses on the extent of the interaction among municipal governments and community groups in an effort to map and understand functional and political relationships between local actors in this dynamic border space.

Distribution and abundance of freshwater polychaetes, Manayunkia speciosa (Polychaeta), in the Great Lakes with a 70-year case history for western Lake Erie

Manayunkia speciosa has been a taxonomic curiosity for 150years with little interest until 1977 when it was identified as an intermediate host of a fish parasite (Ceratomyxa shasta) responsible for fish mortalities (e.g., chinook salmon). Manayunkia was first reported in the Great Lakes in 1929. Since its discovery, the taxon has been reported in 50% (20 of 40 studies) of benthos studies published between 1960 and 2007. When found, Manayunkia comprised <1% of benthos in 70% of examined studies. In one extensive study, Manayunkia occurred in only 26% of 378 sampled events (1991–2009). The taxon was found at higher densities in one area of Lake Erie (mean=3658/m2) and Georgian Bay (1790/m2) than in five other areas (mean=60 to 553/m2) of the lakes. A 70-year history of Manayunkia in western Lake Erie indicates it was not found in 1930, was most abundant in 1961 (mean=8039, maximum=67,748/m2), and decreased in successive periods of 1982 (3529, 49,639/m2), 1993 (1876, 25,332/m2), and 2003 (79, 2583/m2). It occurred at 48% of stations in 1961, 58% in 1982, 52% in 1993, and 6% of stations in 2003. In all years, Manayunkia was distributed primarily near the mouth of the Detroit River. Causes for declines in distribution and abundance are unknown, but may be related to pollution-abatement programs that began in the 1970s, and invasion of dreissenid mussels in the late-1980s which contributed to de-eutrophication of western Lake Erie. At present, importance of the long-term decline of Manayunkia in Lake Erie is unknown.

Of Bridges and Borders: An APSA Congressional Fellow's North American Tale

I had seen once before, halfway around the world, what a new bridge could do to a border region. However, despite having worked in border towns and on border issues for more than a decade, I had never given much thought to the border in my own backyard. I remember crossing the Detroit River to visit the casinos in Windsor, Ontario, before Detroit had her own and seeing the lines of trucks waiting to cross the bridge and being unaware of the border's economic importance to the region and the country. I had studied the economic benefits of European integration, but never thought about how those lessons could be applied to the North American continent. However, last year as a 2011–2012 APSA congressional fellow working with my hometown congressman US Representative Gary Peters I had the opportunity to apply these overseas experiences to a border that mattered to my town, state, and country. The US-Canadian border is not only the world's longest nonmilitarized border, but is also the line separating my hometown Detroit, Michigan, from Windsor, Ontario; and it is the line preventing the region and the two countries from fully realizing their economic potential.

Effects of shoreline type, riparian zone and instream microhabitat on fish species richness and abundance in the Detroit River

Widespread development of shorelines has contributed to habitat loss and degradation, affecting aquatic taxa across a wide range of systems. The nearshore zone offers unique fish habitat, with terrestrial systems providing structure, cover and organic matter. My objective in this study was to examine relationships between shoreline types and fishes in the Detroit River, a large Laurentian Great Lakes connecting channel. I tested the hypothesis that fish species richness and abundance differed with shoreline and riparian zone type and explored the relative importance of instream microhabitat on these relationships. Fishes were sampled in three seasons using two sampling methods, and instream microhabitats were quantified at each sampling location. No differences were observed in fish species richness or abundance among riparian zone or shoreline types, though comparisons between developed and natural shorelines were constrained by a small number of samples at natural shorelines. The lack of differences among shoreline and riparian zone types was consistent across seasons and between sampling methods. Instream microhabitat explained the greatest variation in fish species richness and abundance, and only minor variation was explained jointly by microhabitat and shoreline type. Though local effects of shoreline development were not observed, widespread shoreline development may affect Detroit River fishes at the ecosystem scale, and future mechanistic studies of the ecological changes accompanying shoreline development are warranted. The importance of instream microhabitat variables demonstrates that shoreline restoration projects involving improvements to instream habitat, in addition to altering the shoreline itself, will provide the greatest benefits to large-river fishes.

Spatial distributions and temporal trends in polybrominated diphenyl ethers in Detroit River suspended sediments

Suspended sediments from the Detroit River were collected using sediment traps at sites ranging from western Lake Erie to southern Lake St. Clair to assess spatial distributions and temporal trends of polybrominated diphenyl ethers (PBDEs). The distribution of PBDEs in suspended sediments in the Detroit River appeared influenced by shoreline-based contemporary urban and industrial activities, which stood in contrast to PCBs that were associated with areas of historic industrial activity. Temporal trend data indicate that total PBDE concentrations decreased in the period after 2000 in response to cessation of production of the penta- and octa BDE formulations. Concentrations of total PBDEs ranged from roughly 7ngg−1 (4ngg−1 BDE 209) in southern Lake St. Clair to several hundred ngg−1 (60–180ngg−1 BDE 209) in the lower reaches of the Detroit River. The widespread occurrence of PBDEs in Detroit River suspended sediments suggests that large urban areas can act as diffuse sources of these chemicals that are used in modern industrial applications and consumer products.

Genetic connectivity and diversity of walleye (Sander vitreus) spawning groups in the Huron–Erie Corridor

The Huron–Erie Corridor (HEC) connects the upper and lower Great Lakes, providing key fish passage. A century of channelization, dredging, and pollution has led to habitat loss and declining fish numbers. Since 2004, the multi-agency HEC initiative augmented fish spawning habitat at Belle Isle and Fighting Island in the Detroit River, whose populations are examined here. We analyze genetic patterns among seven spawning groups (N=311) of walleye Sander vitreus, a key fishery species, using nine nuclear DNA microsatellite loci and mitochondrial DNA control region sequences. Results reveal that all spawning groups contained appreciable genetic diversity (microsatellites: HO=0.72; mtDNA: HD=0.73) and showed a mixture of connectivity and divergence. Genetic relationships did not fit an isolation by geographic distance hypothesis, with some closely spaced populations being very different. Notably, the Flint River–Lake Huron spawning group was the most divergent, showing no genetic exchange. The Belle Isle and Fighting Island populations markedly differed, with the latter showing some genetic exchange with the Grosse Ile (Detroit River) and the Huron River (northwest Lake Erie) populations to the south. Walleye spawning at Fighting Island experienced no significant change in overall genetic diversity pre- versus post-habitat augmentation, but the allelic frequency changed. Our results comprise an important baseline for future population analyses and habitat assessment of these habitat augmentation areas. Despite habitat degradation and pollution, it appears that historic walleye spawning groups have persisted along the HEC, meriting continued genetic monitoring and further restoration efforts to conserve and enhance this important and diverse fishery.

Genetic diversity and divergence of yellow perch spawning populations across the Huron–Erie Corridor, from Lake Huron through western Lake Erie

The yellow perch Perca flavescens supports one of the largest Great Lakes fisheries, whose populations have varied due to environmental changes, including exploitation and habitat degradation. The Huron–Erie Corridor (HEC) connects the upper and lower Great Lakes, running from Lake Huron through the St. Clair River, Lake St. Clair, and Detroit River to western Lake Erie; it serves as an essential fish migration corridor, and contains key spawning and nursery grounds. Its shipping importance led to its extensive channelization and dredging, destroying and degrading habitats. Since 2004, the HEC Initiative has restored some fish spawning and nursery grounds. Our objective is to assess the genetic diversity, connectivity, and divergence of yellow perch spawning populations along the HEC to provide a baseline for assessing future patterns, including responses to improved habitat. Genetic variation of seven spawning populations (N=248), four in the HEC, one in Lake Huron, and two in western Lake Erie, are analyzed at 15 nuclear microsatellite loci. Results showed appreciable genetic diversity of the seven spawning populations (mean observed heterozygosity=0.637±0.020, range 0.568–0.699), which significantly differed in genetic composition (θST=0.011–0.099, p<0.0001–0.0007), suggesting a history of genetic isolation; relationships did not follow a pattern of genetic isolation by geographic distance. Notably, some nearby spawning populations were very genetically distinctive, with high genetic diversity and high proportions of private alleles, as characterized by the Belle Isle restoration site in the Detroit River. Our study provides a genetic benchmark to assess ongoing and future habitat restoration efforts across the HEC and beyond.

African American and African Canadian Transnationalism along the Detroit River Borderland: The Example of Madison J. Lightfoot

African American and African Canadian Transnationalism along the Detroit River Borderland: The Example of Madison J. Lightfoot