Organochlorine Contaminant Residues in Young-of-the-Year Spottail Shiners from Lakes Ontario,Erie, and St. Clair

The spottail shiner (Notropis hudsonius) was found to be a useful biological integrator of organochlorine contaminants in near-shore habitats. During the fall of 1975 spottail shiners were collected from nine sampling sites on Lakes Ontario, Erie and St. Clair. The restricted home range of the young-of-the-year spottail and its relatively short exposure to contaminants facilitated localized residue level assesment and reflected on recent contaminant loadings. Contaminant types and residue levels in fish generally reflected the regional land-practices. All samples analyzed contained PCB and DDT residues, while some also contained heptachlor epoxide, dieldrin, endrin and chlordane. Mean PCB concentrations for theyoung-of-the-year spottails ranged from 59 ng/g - 844 ng/g wet weight, while total DDT residues ranged from 32 ng/g - 244 ng/g. The mean PCB residue concentrations in seven of the nine fish collections tested exceeded the 100 ng/g body burden level recommended for protection of wildlife by the I.J.C.     

Organochlorine Contaminant Residues in Spottail Shiners (Notropis Hudsonius) from the Niagara River

Collections of young-of-the-year spottail shiners (Notropis hudsonius) were used to determine spatial distribution (1981) of organochlorine residues and their temporal trends in the Niagara River. PCB and mirex residues in spottail shiners ranged from 164 to 573 ng/g and ND-18 ng/g, respectively. PCB and mirex residues exceeded the aquatic life objectives (Great Lakes Water Quality Agreement of 1978) at all sites except Frenchman's Creek, where mirex was non-detectable. Residues for heptachlor, heptachlor epoxide, aldrin, endrin, chlordane, thiodan, dieldrin, BHC, and DDT were low or non-detectable in Niagara River spottail shiners. Chlorinated benzene and octachlorostyrene residues were also present in most Niagara River spottail shiner samples analyzed. Dioxin (2,3,7,8- TCDD) was present in all Niagara River spottail shiner collections and ranged from 4 to 60 pg/g. The highest dioxin residues were found at Cayuga Creek, N. Y. PCB residues have declined significantly since 1975 in Niagara-on-the-Lake spottail shiners; however, residues increased in 1980 and 1981, although they were below the 1975 concentrations. Mirex residues in spottail shiners from Niagara-on-the-Lake have also declined significantly since 1978, suggesting reduced mirex inputs to Lake Ontario.     

Butyltin Species and Inorganic Tin in Water and Sediment of the Detroit and St. Clair Rivers

Water and sediment samples from 29 locations in the Detroit and St. Clair rivers were analyzed for the highly toxic tri-n-butyltin (Bu₃Sn⁺) species and for the less toxic di-n-butyltin (Bu₂Sn²⁺) and n-butyltin (BuSn³⁺) species and inorganic tin. In general, locations sampled in the St. Clair River were less contaminated with butyltin species than those in the Detroit River. Inorganic tin and BuSn³⁺ were detected in over 90% of all subsurface water samples, while Bu₂Sn²⁺ and Bu₃Sn⁺ were detected in 45 and 28% of the same samples, respectively. The highest concentration ofBu₃Sn⁺ in subsurface water, 5.9 × 10^?10 mol Sn/L, was at the mouth of the Ecorse River, a tributary of the Detroit River. The three butyltin species and inorganic tin were also detected in 23–46% of all sediment samples. The highest concentrations of Bu₃Sn⁺ in sediment were found close to the mouths of the River Rouge, another tributary of the Detroit River, and the Ecorse River, and were 6.2 × I0^–7 and 1.7 × I0^–7 mol Sn/kg dry weight, respectively, for the top 2 cm of sediment.     

Occurrence of Alkyllead Compounds in the Detroit and St. Clair Rivers

Environmental occurrence of alkyllead compounds, both of molecular species, e.g., tetraalkyllead, and ionic species, e.g., dialkyllead and trialkyllead, is believed to be derived mainly from anthropogenic sources such as effluents of alkyllead production plants and from slow degradation of tetraalkyllead in the environment. The present study describes a survey for the occurrence of tetraalkyllead, trialkyllead, dialkyllead, and Pb(II) (R = Me, Et) in water, surface microlayer, fish, and sediments from 29 stations in the St. Clair and Detroit rivers, including the western basin of Lake Erie. Results indicated that triethyllead and diethlylead compounds have been found for the first time in fish and surface microlayer in St. Clair River near Corunna where a production plant is located. About 48% of the surface microlayer samples contained various alkyllead compounds whereas only one water sample taken from the St. Clair River was found to contain alkyllead. Alkyllead compounds were found in several species of fish caught in the St. Clair River, with northern pike containing the highest concentration of alkyllead (0.173 μg/g) followed by white sucker, carp, and walleye. The concentrations of alkyllead in some individual fish reached the p.p.m. level which is considered highly hazardous for consumption although health criteria for alkyllead are not yet available. The ratios of alkyllead to total lead ranged from 0% for yellow perch and brown trout to 56% for carp.     

Chlorinated Contaminants in Surficial Sediments of Lakes Huron,St. Clair,and Erie: Implications Regarding Sources Along the St. Clair and Detroit Rivers

Surficial sediments from southern Lake Huron, Lake St. Clair, and Lake Erie have been analyzed for a broad spectrum of chlorinated organics including PCBs, chlorobenzenes, and several pesticides. The differences between sediment contaminant concentrations in Lake Huron and Lake St. Clair indicated sources of hexachlorobenzene, hexachlorobutadiene, octachlorostyrene, and several other chlorinated benzenes along the St. Clair River. Similar differences between sediment PCB concentrations in Lakes Huron/St. Clair and Lake Erie indicated major PCB sources along the Detroit River. Specific PCB congener analysis revealed that PCBs discharged to the Detroit River contained especially high concentrations of highly chlorinated hexa-, hepta-, and octachloro-biphenyls which are major constituents of the industrial mixture Aroclor 1260. The analysis of individual PCB congeners made it possible to trace PCBs of Detroit River origin to the central and eastern basins of Lake Erie, and to estimate the contribution of the Detroit River to the PCB burden in sediments of these basins.     

Surface Deposition of Lead and Cadmium from the Atmosphere in the Detroit River—Lake St. Clair Region

The research reported here forms part of a large multidisciplinary study of four toxic contaminants — lead, cadmium, PCBs, and octachlorostyrene in the Essex region of southwestern Ontario. The purpose of this part of the project is to quantify the atmospheric loading of the metallic contaminants. A bulk precipitation sampler, wet-only precipitation sampler, and recording rain gauge were installed at an urban and rural site. Results from 2 years of data indicate that atmospheric loading of lead is 40–50 times that of cadmium in the city and 16–40 times that of cadmium in the rural areas. Lead loadings in the city were found to be 2–4 times higher than in the rural areas, while cadmium loadings appeared to be similar in both areas. Concentrations of the metals are higher in winter than in summer, but because of higher summer precipitation surface loadings are similar in both seasons. Preliminary statistical analysis indicates that concentrations of the metals are related to intensity and amount of precipitation but not usually to wind direction.     

Geochemical Availability of Some Trace and Major Elements in Surficial Sediments of the Detroit River and Western Lake Erie

Surficial bottom sediment from twenty locations in the Detroit River and western Lake Erie has been analyzed for potentially available Ba, Be, Cd, Cr, Co, Cu, Pb, Mn, Mo, Ni, P, V, and Zn. The highest concentrations of all but one of these elements were found at a station at the river-lake interface very close to a dumping ground. The environmental mobility of Cd, Zn, Co, Pb, Cr, Ni, and P is controlled by hydrous iron oxides, whereas V and Mo is controlled by aluminosilicates. The iron oxide phase exhibits a very high sorption capacity for phosphorus (molar adsorption coefficient = .361) which is attributed to the high loadings of Fe and P at the confluence of the Rouge and Detroit rivers as well as continuous inputs along the length of the Detroit River. It is suggested that phosphorus controls instituted in the 1970s will probably result in the iron oxide phase having greater sorption capacity for toxic metals because of the decreasing competition from phosphorus for binding sites.     

Organochlorine Pesticides,PBBs, And Mercury in Round Whitefish Fillets from Saginaw Bay,Lake Huron, 1977–1978

Successful development of a commercial, small-mesh trap net fishery for round whitefish (Prosopium cylindraceum) in Saginaw Bay, Lake Huron, prompted analysis of round whitefish fillets for selected contaminants [dieldrin, dichlorodiphenyl trichloroethane and metabolites (DDT), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), chlordane, methyl mercury, and total mercury] to determine the fish's suitability for human consumption. Concentrations of all contaminants measured in 1977–1978 were below U. S. Food and Drug Administration action guidelines for fish; PBBs were below detection limits (0.001 mg/kg) for all fillets analyzed. Only PCBs and total DDT residues displayed a strong direct relationship with fish length. Fillets from males consistently exhibited higher mean concentrations of contaminants than did females. No changes in contaminant levels with season were observed.     

Relationships between wind-driven and hydraulic flow in Lake St. Clair and the St. Clair River Delta

A three-dimensional hydrodynamic forecasting model of the Great Lakes Huron-Erie Corridor is used to investigate mixing and the relationship between hydraulic and wind-induced currents in a shallow lake system in which lake inflows come through several channels of a river delta. The hydrodynamics in Lake St. Clair and the channels of the St. Clair River Delta are evaluated for (1) a one-year simulation from 1985 including water age calculation, (2) 8 different wind direction scenarios, and (3) a storm event. Observations and model simulations show distinct regions in the lake in which currents are forced by either hydraulic flow from the river system or from wind stress over the lake. However, during severe storm events, these regions are found to shift or even disappear due to changes in the delta channel inputs into the lake. These changes underscore the need for realistic, unsteady river flow boundary conditions at interfaces between a shallow lake and river delta. Steady inflow conditions will not allow for potential shifting of these current zones, and will also fail to resolve flow retardation or reversals during storm events.     

Finite Element Circulation Model for Lake St. Clair

In the numerical modeling of a toxic chemical in a lake, it is necessary to solve the hydrodynamics of the transporting flow as well as the transformation processes of the pollutant in the lake. It is important to calibrate and verify the model before predictive applications. A simple numerical hydrodynamic model which includes wind stress, bottom friction, Coriolis force, inflow, outflow, and the bottom topography of the lake has been developed and verified with field data for Lake St. Clair. The overall root mean square differences between predicted and measured current magnitudes and directions were 1.30 cm s^-1 and 22.5°, respectively, while the correlation coefficients were 0.99 and 0.95, respectively. The hydrodynamic model was tested for stability, convergence, and sensitivity to parameters such as wind shear, wind direction, and vertical eddy viscosity effects. This model is used to generate the typical lake circulation patterns for different steady state wind and ice conditions that are required for the long-term pollutant simulation models such as the EPA (TOXIWASP) model. The depth average velocities were also used in a finite element pollutant transport model. An upwind finite element formulation was used to obtain a stable solution for the convective transport phenomena. The predicted pollutant (chloride ion) concentration pattern was compared with observed field data and fairly good agreement was obtained.     

Aromatic Hydrocarbons in Biota from the Detroit River and Western Lake Erie

Polynuclear aromatic hydrocarbons (PAHs) and PCBs in zebra mussels were elevated to concentrations greater than 5,000 ng/g lipid and 15,000 ng/g lipid, respectively, at the Ambassador Bridge in the Detroit River and concentrations gradually declined at downstream locations, which included three stations in the western basin of Lake Erie (Middle Sister Island, East Sister Island, Pelee Island). PCB concentrations in zebra mussels collected at the stations in western Lake Erie were elevated relative to the concentrations in mussels at the upstream end of the Detroit River (Stoney Point). There is no evidence that PAH contamination in the Detroit River elevated PAH concentrations in zebra mussels in western Lake Erie relative to mussels at Stoney Point. Fluorescent aromatic compounds (FACs) representing metabolites of PAHs were analyzed in the bile of gizzard shad (Dorosoma cepedianum) and freshwater drum (Aplodinotus grunniens) collected from several sites in the Detroit River and western Lake Erie. Mean FAC concentrations were >l,000 ng BaP equivalents per mL of bile in fish from the Trenton Channel and Boblo Island in the Detroit River, but FAC data provided no evidence that fish captured at two sites in western Lake Erie (East Sister Island, Pelee Island) were exposed to elevated concentrations of PAHs through ingestion of contaminated biota or exposure to contaminated sediments.     

Temporal and spatial trends of organochlorines and mercury in fishes from the St. Clair River/Lake St. Clair corridor,Canada

The temporal and spatial relationships of a suite of organochlorine contaminants and mercury were examined in various fish species of the St. Clair River/Lake St. Clair corridor, Canada, in order to evaluate the effectiveness of remediation efforts and to assess the risk to human and wildlife fish consumers. In Lake St. Clair, fish tissue concentrations of mercury, polychlorinated biphenyls (PCBs), octachlorostyrene (OCS), hexachlorobenzene (HCB), and dichlorodiphenyltrichloroethane (DDT) decreased consistently from the 1970s until the 1980s and 1990s, after which the rate of contaminant decline slowed or concentrations stabilized. This trend was consistent in up to 13 species (both young-of-the-year and adult fishes) comprising different trophic positions and dietary habits, suggesting that the changes were reflective of ambient conditions rather than food web processes. Elevated concentrations of mercury, PCBs, OCS, HCB, and DDT were detected in St. Clair River young-of-the-year spottail shiner compared with fish from Lake Huron, indicating that non-atmospheric inputs of these chemicals, likely originating from sediment, remain in the St. Clair River. Current concentrations of mercury and PCBs, and mercury, PCBs, and DDT remain of concern to human and wildlife fish consumers, respectively. Given that contaminant decreases have generally stabilized in fish, we suggest that further natural recovery of contaminants in St. Clair corridor fishes will be slow since contaminants will likely continue to be influenced by sediment levels.     

Temporal Effects of St. Clair River Dredging on Lakes St. Clair and Erie Water Levels and Connecting Channel Flow

A Great Lakes hydrologic response model was used to study the temporal effects of St. Clair River dredging on Lakes St. Clair and Erie water levels and connecting channel flows. The dredging has had a significant effect on Great Lakes water levels since the mid-1980s. Uncompensated dredging permanently lowers the water levels of Lakes Michigan and Huron and causes a transitory rise in the water levels of Lakes St. Clair and Erie. Two hypothetical dredging projects, each equivalent to a 10 cm lowering of Lakes Michigan and Huron, were investigated. This lowering is approximately half the effect of the 7.6 and 8.2 meter dredging projects. In the first case the dredging was assumed to occur over a single year while in the second it was spread over a 2-year period. The dredging resulted in a maximum rise of 6 cm in the downstream levels of Lakes St. Clair and Erie. The corresponding increase in connecting channel flows was about 150 m³s^?1. The effects were found to decrease over a 10-year period with a half-life of approximately 3 years. The maximum effects on Lake Erie lagged Lake St. Clair by about 1 year.     

Water Currents in the St. Clair and Detroit Rivers

A 2-D hydrodynamic finite element model (RMA-2V) with mesh generation tools (Fast-TABS) is used to simulate the current velocities in the St. Clair and Detroit rivers. The required shorelines and spot depths were digitized from the bathymetric charts and the NOS (National Ocean Service) hydrographic database using Geographic Information Systems technology. The field data obtained from the tracking of drogues via aerial time-lapse photography were used to calibrate the model. A statistical comparison between field and simulated data revealed a very good agreement between the simulated and observed currents.     

Application of distance sampling techniques for diving ducks on Lake St. Clair and western Lake Erie

Lake St. Clair and western Lake Erie are important migration staging areas for diving ducks including canvasbacks (Aythya valisineria), redheads (Aythya americana), and lesser and greater scaup (Aythya affinis and Aythya marila). Starting in 1983, the Michigan Department of Natural Resources (MDNR) attempted to census diving ducks on the United States portion of Lake St. Clair throughout autumn migration; however, in 2010 the MDNR expanded the traditionally surveyed area to include all of Lake St. Clair and a portion of western Lake Erie. The idea of achieving a census over the expanded study area was unrealistic, and instead distance sampling techniques were adopted in an effort to generate statistically valid estimates of detection probabilities and abundances for diving ducks during spring and autumn migration. We found distance sampling techniques to be a viable option for estimating diving duck abundance as long as flock size is accounted for as a covariate affecting the detection function. Diving ducks were generally more abundant on our study area during autumn migration with a mean of 306,327 ducks/survey (SE = 40,729) compared to an average spring abundance of 91,053 ducks/survey (SE = 19,175). Peak abundance occurred on 20 November 2012 with an estimated 596,335 diving ducks on Lake St. Clair and western Lake Erie. Ultimately, our methodology could be used to establish long-term, standardized data collection techniques and applied to conservation planning for waterfowl in the Great Lakes region.     

Distribution of Hydrocarbons and Chlorinated Hydrocarbons in Various Phases of the Detroit River

Concentrations of several chlorohydrocarbons, polychlorinated biphenyls, and polynuclear aromatic hydrocarbons in the Detroit River were measured. For purposes of this study, the river ecosystem was divided into six phases or compartments: sediments, pore water in the sediments, suspended solids, subsurface water, surface microlayer, and air. Significant amounts of the above mentioned compounds occur in all of these compartments except air (for which our detection was relatively insensitive). The sediments contained over 99% of the chlorinated compounds. The polynuclear aromatic hydrocarbons were distributed between the subsurface water and the sediments.     

Biological Monitoring of Organochlorine Contaminants in the St. Clair and Detroit Rivers Using Introduced Clams, Elliptio Complanatus

Introduced clams (in cages) were effective biomonitors in determining the distribution, biological availability, and source areas of a number of chlorinated organic contaminants in the St. Clair River-Detroit River corridor during 1982 and 1983. In the St. Clair River, hexachlorobenzene (HCB), octachlorostyrene (OCS), pentachlorobenzene (QCB), hexachlorobutadiene (HCBD), 2,3,6-trichlorotoluene (TCT), and alpha-BHC were most frequently identified in tissues after 3 weeks’ exposure. When compared to other locations in the St. Clair and Detroit rivers, significantly (p<0.05) higher levels of QCB, HCB, OCS, and HCBD were found in clams exposed along the Sarnia to Corunna, Ontario, shoreline. Elevated concentrations of HCB and OCS were also detected in water samples from this section of the river. TCT was found in clams from most locations, at low levels, with no obvious source area. Low levels of polychlorinated biphenyls (PCBs) were restricted to clams from the Sarnia area. In the Detroit River, PCBs, HCB, and OCS were most frequently detected in clams. PCB levels were significantly (p<0.05) higher along the Michigan shore and the highest concentrations were found in the Rouge River area. PCBs were also detected in some water samples from urbanized areas of the river. HCB and OCS were found at near-detection levels in clams from most stations. Contaminant levels in clams from around Fighting Island were low or non-detectable, indicating an absence of biologically available organochlorine contaminants in this area of the river. In the St. Clair River, p,p-DDE was only detected in the Sarnia area, whereas it was found in clams from both sides of the Detroit River, also at low levels. Aldrin, chlordane, and DDT were only sporadically detected in both rivers.     

An ecosystem health assessment of the Detroit River and western Lake Erie

The Canada-U.S. State of the Strait Conference is a biennial forum with a 22-year history of assessing ecosystem status and providing advice to improve research, monitoring, and management of the Detroit River and western Lake Erie. The 2019 conference focused on assessing ecosystem health based on 61 indicators. Although there has been considerable improvement in the Detroit River since the 1960s, much additional cleanup is needed to restore ecosystem health. Western Lake Erie is now at risk of crossing several potential tipping points caused by the interactions of a variety of drivers and their stresses. This assessment identified eight environmental and natural resource challenges: climate change; population growth/transportation expansion/land use changes; chemicals of concern; human health/environmental justice; aquatic invasive species; habitat loss/degradation; nonpoint source pollution; and eutrophication/harmful algal blooms. Specific recommendations for addressing each challenge were also made. Climate change is the most pressing environmental challenge of our time and considered a “threat multiplier” whereby warmer, wetter, and more extreme climatic conditions amplify other threats such as poor air quality effects on vulnerable residents, species changes, and nonpoint source runoff and combined sewer overflow events that contribute to eutrophication and can manifest as harmful algal blooms. Our assessment found that investments in monitoring and evaluation are insufficient and that the region's intellectual and environmental capital is not being leveraged sufficiently to address current challenges. Continued investment in this transnational network is essential to support ecosystem-based management.     

Distribution of Mercury,Trace Organics,and Other Heavy Metals in Detroit River Sediments

In 1980 the Ontario Ministry of the Environment carried out a surficial bottom sediment survey of the Detroit River. The survey was designed to update changes in sediment mercury levels from a 1970 study, and to determine the spatial distribution of trace organics and other heavy metals as a baseline for future investigations. The contamination of sediments along the Ontario shoreline of the river was localized near known inputs such as Little River, the West Windsor sewage treatment plant, Turkey Creek, and Riviere aux Canards. Almost the entire U.S. shoreline sediments exhibited elevated levels (above provincial dredging guidelines) of contaminants such as heavy metals and PCBs. Levels of one order of magnitude higher than those on the Canadian shore were prevalent along the U.S. shore. Mercury levels exhibited a substantial decline during the period 1970–1980. Increases in chromium, copper, lead, and zinc in the vicinity of the mouth of the Rouge River along the U.S. shoreline during the same period suggest both recent and continuing inputs from industrial and municipal sources.     

An Introduction to the Niagara River/Lake Ontario Pollution Problem

Considerable public concern about contamination of Lake Ontario has been generated by suspected leakage of toxic chemicals from a multitude of hazardous waste dumps and by the several major chemical outfalls along the United States side of the upstream Niagara River. A cooperative effort by Canadian and United States research scientists has begun to provide the basic information which may be required to enforce controls of loadings of toxic chemicals to this river/lake system. A holistic ecosystem approach, involving analyses of many contaminants in a variety of aquatic media, is necessary to properly manage the problem and assist in setting priorities.