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Research about Canada, United States

Source-linked reports with geographic coverage including Canada, United States.

At least 1,045 records · Page 58Linked to original sources
USGS2002

Metal concentrations in zebra mussels and sediments from embayments and riverine environments of eastern Lake Erie, southern Lake Ontario, and the Niagara River

Concentrations of 14 metals were studied in the soft tissues of zebra mussels ( Dreissena polymorpha ) and sediments from 16 Great Lakes embayments and riverine environments. Samples were collected in 1993 and 1994 during the early and late autumn period when the body mass of mussels is least affected by reproductive activities. There was a significant difference in geometric mean concentrations of all metals except Cu in mussels sampled from different sites, and there was a significant difference in the geometric mean concentrations of all metals but Cd, Mn, and Zn between years. The higher metal concentrations in mussels from this study were generally similar to those in mussels from contaminated European and U.S. locations, and those with lower concentrations were similar to those from uncontaminated European and U.S. locations. Geometric mean sediment concentrations of all metals differed significantly among sites. Sediment concentrations of metals from some sites were above EPA guidelines for moderately polluted harbor sediments. Sites where zebra mussels had higher concentrations of Al, Cr, and V tended to be the same sites as those where sediment concentrations of these metals were also higher. However, there was not a significant statistical relationship between concentrations of metals in zebra mussels and sediments, except for Mg.

Lake Erie, Lake Ontario, Niagara River↗
USGS2002

The relationship between the abundance of smallmouth bass and double-crested cormorants in the eastern basin of Lake Ontario

Available population and diet data on double-crested cormorant ( Phalacrocorax auritus ) and smallmouth bass ( Micropterus dolomieui ) numbers, demographics, and exploitation rates were synthesized to examine the relationship between cormorant and smallmouth bass abundance in the U.S. waters of the eastern basin of Lake Ontario. It was found that after the number of cormorants nesting on Little Galloo Island in New York exceeded 3,500 pairs in 1989, survival of young smallmouth bass, not yet of legal size for the sport harvest (< 305 mm), began to decline. Despite production of strong year classes in 1987 and 1988, abundance of smallmouth bass measured from gill net surveys declined to its lowest level by 1995 and remained there through 1998. Stable or increasing catch and harvest rates in other local fisheries along the U.S. shore suggested that declines in smallmouth bass abundance in the eastern basin were not related to water quality. Stable or increasing growth rates for smallmouth bass age 2 and older since the 1980s further indicated that food resource limitation was also not the cause for declines in abundance. Comparisons of estimates of size and age-specific predation on smallmouth bass by cormorants with projected smallmouth bass population size indicated that much of the increased mortality on young smallmouth bass, could be explained by cormorant predation.

Lake Ontario↗
USGS2002

Flow distribution in selected branches of St. Clair and Detroit rivers

St. Clair and Detroit rivers, which are connecting channels between Lake Huron and Lake Erie in the Great Lakes basin, form part of the boundary between the state of Michigan and the province of Ontario. In 13 reaches, this flow divides locally around islands and dikes to form 31 branches. This study develops a set of simple linear regression equations for computing expected flow proportions in branches, generally as a function of the total flow within the reach. The equations are based on 533 acoustic Doppler current profiler measurements of flow obtained between 1996 and 2000. Root-mean-square errors of these regressions range from 0.00323 to 0.0895. In seven upstream reaches where flow is known because of flow specifications at the boundaries of the waterway and continuity constraints, the uncertainties of the flow proportions can be used to directly infer the uncertainties of the corresponding flows. In six downstream reaches, the uncertainties of flows are determined by both the uncertainties of the flow proportions and the uncertainties of the total flow in the reach. For these reaches, Monte Carlo simulations quantify the ratios of total uncertainty to flow proportion uncertainty, which range from 1.0026 to 13.984. To facilitate routine calculation, polynomial regression equations are developed to approximate these ratios as a function of flow. Results provide a mechanism for computing the magnitudes and uncertainties of steady-state flows within selected branches of the connecting channels by specifying inflows at the headwaters of St. Clair River, seven intervening tributaries, and Lake St. Clair.

Michigan, Ontario↗
USGS2002

Evaluation of potential impacts on Great Lakes water resources based on climate scenarios of two GCMs

The results of general circulation model predictions of the effects of climate change from the Canadian Centre for Climate Modeling and Analysis (model CGCM1) and the United Kingdom Meteorological Office's Hadley Centre (model HadCM2) have been used to derive potential impacts on the water resources of the Great Lakes basin. These impacts can influence the levels of the Great Lakes and the volumes of channel flow among them, thus affecting their value for interests such as riparians, shippers, recreational boaters, and natural ecosystems. On one hand, a hydrological modeling suite using input data from the CGCM1 predicts large drops in lake levels, up to a maximum of 1.38 m on Lakes Michigan and Huron by 2090. This is due to a combination of a decrease in precipitation and an increase in air temperature that leads to an increase in evaporation. On the other hand, using input from HadCM2, rises in lake levels are predicted, up to a maximum of 0.35 m on Lakes Michigan and Huron by 2090, due to increased precipitation and a reduced increase in air temperature. An interest satisfaction model shows sharp decreases in the satisfaction of the interests of commercial navigation, recreational boating, riparians, and hydropower due to lake level decreases. Most interest satisfaction scores are also reduced by lake level increases. Drastic reductions in ice cover also result from the temperature increases such that under the CGCM1 predictions, most of Lake Erie has 96% of its winters ice-free by 2090. Assessment is also made of impacts on the groundwater-dependent region of Lansing, Michigan.

Great Lakes basin↗
USGS2002

Palynology of Eocene strata in the Sagavanirktok and Canning Formations on the North Slope of Alaska

This paper describes, illustrates, and interprets Eocene palynomorph assemblages from the North Slope of Alaska, mainly from 31 outcrop samples from seven stratigraphic sections at Franklin Bluffs on the Sagavanirktok River. The top of the Sagwon Member of the Sagavanirktok Formation is shown to be a thin, coaly, apparently nonmarine sequence almost certainly of early Eocene age; the remainder of the member has long been known to be Paleocene in age. The remaining six sections at Franklin Bluffs contain silty, sandy, and clayey strata and are in the Franklin Bluffs Member of the Sagavanirktok Formation in the type area of this member. Dinocyst and pollen data from the Franklin Bluffs Member suggest mainly an early Eocene age, but some strata might be middle Eocene. In all samples from the type Franklin Bluffs Member that contained reasonably well preserved dinocyst assemblages, the environment of deposition was nearshore marine or estuarine. The Franklin Bluffs Member is the temporal equivalent of the marine Mikkelsen Tongue of the Canning Formation, whose type locality is approximately 90 km to the east–northeast. Previous pollen and plant megafossil data from the Arctic showed that the early to middle Eocene climate of the North Slope of Alaska was warm temperate, perhaps nearly subtropical. At least 20 pollen taxa present in the Eocene of the North Slope also occurred as far south in North America as the Gulf Coast and therefore had enormous latitudinal ranges. Several of these taxa appear to have migrated north to the Arctic Coast, probably mainly in the latest Paleocene, at the beginning of the climatic thermal maximum for the Tertiary. However, there is also evidence that plants producing modern-looking grains of Carya, Juglans, and Liquidambar migrated southward from the Arctic to the Gulf Coast after the early Eocene.

Alaska, Northwest Territories↗
USGS2002

Geographic variation in the black bear (Ursus americanus) in the eastern United States and Canada

The pattern of geographic variation in morphologic characters of the black bear ( Ursus americanus ) was assessed at 13 sites in the eastern United States and Canada. Thirty measurements from 206 males and 207 females were recorded to the nearest 0.01 mm using digital calipers and subjected to principal components analysis. A matrix of correlations among skull characters was computed, and the first 3 principal components were extracted. These accounted for 90.5% of the variation in the character set for males and 87.1% for females. Three-dimensional projection of localities onto principal components showed that, for males and females, largest individuals occurred in the more southern localities (e.g., males--Louisiana-Mississippi, eastern Texas; females--Louisiana-eastern Texas) and the smallest animals occurred in the northernmost locality (Quebec). Generally, bears were similar morphologically to those in nearby geographic areas. For males, correlations between morphologic variation and environmental factors indicated a significant relationship between size variation and mean January temperature, mean July temperature, mean annual precipitation, latitude, and actual evapotranspiration; for females, a significant relationship was observed between morphologic variation and mean annual temperature, mean January temperature, mean July temperature, latitude, and actual evapotranspiration. There was no significant correlation for either sex between environmental factors and projections onto components II and III.

Southwestern Naturalist↗
USGS2002

USGS capabilities for interdisciplinary investigations in coastal and nearshore ecosystems of the Great Lakes

People choose to reside, work, and vacation in coastal areas of the Great Lakes because of the lakes' scenic beauty and their historic and cultural features. Great Lakes nearshore areas also constitute a valuable economic resource. Two million anglers added \$1 billion to the region's economy in 1996. More than 300 million tons of goods were transported out of major Great Lakes ports at a value of \$3 billion in 1996. A 1998 survey of Lake Erie beaches estimated contributions of $5 million per year to each local economy with a public beach. More than 70 million people yearly visit national, state and provincial parks in the Great Lakes area. Uncontrolled land development, recreational development, invasive species, climate change, water availability, and water-level changes and fluctuations lead a long list of current and potential issues in coastal and nearshore areas. To be effectively addressed, these complex issues require an interdisciplinary approach.

Great Lakes↗
USGS2002

Visualization of drifting buoy deployments on upper Detroit River within the Great Lakes Waterway from August 28-30, 2001

Detroit River is a connecting channel on the Great Lakes waterway that joins Lake St. Clair with Lake Erie. The river forms part of the international boundary between the United States and Canada in southeastern Michigan and southern Ontario. Drifting buoys were deployed on Detroit River to help investigate flow characteristics of four selected reaches as part of a source water assessment study of public water intakes. The drifting buoys contained global positioning system (GPS) receivers to help track their movements following their deployment. In some deployments, buoys were released across a transect at approximately uniform intervals to better understand flow patterns. In other deployments, buoys were released in clusters to investigate turbulent dispersion characteristics. Computer animations of buoy movements, which can be viewed through the Internet, are developed to help visualize the results of the buoy deployments.

Detroit River↗
USGS2002

Strategic vision for the U. S. Geological Survey in the Great Lakes-St. Lawrence Region, 2001-2010

The U.S. Geological Survey's (USGS) strategic vision for the Great Lakes-St. Lawrence Region is that of a healthy ecosystem, whose ecological integrity and economic health are nurtured and sustained through sound resource-management decisions based on reliable, timely, and objective scientific information and data. The USGS is a leader in providing reliable, relevant, timely, and objective scientific data and information at local, statewide, regional, national, and international scales to assist in the management and restoration of the natural resources in the Great Lakes-St. Lawrence Region. The mission of the USGS in the Great Lakes-St. Lawrence Region is to provide natural science information to the broad community of policymakers, resource managers, regulators, scientists, and private citizens who contribute to informed decisions concerning natural-resource management practices and ecosystem quality and integrity. The strategic vision for the USGS in the Great Lakes-St. Lawrence Region is a plan to address complex issues that require integrated natural-science information. The strategic vision describes how the USGS will coordinate existing programs and draw upon the strengths of the entire organization. It provides the framework for long-term coordination and integration of USGS Programs and activities over the next decade (2001-10). The strategic vision describes the role of the USGS in the Great Lakes-St. Lawrence Region, the coordination of activities within and outside the Bureau and Department of Interior, and interactions between the USGS and its cooperators, partners, and stakeholders in the Region.

Great Lakes-St. Lawrence region↗
USGS2002

Visualization of a drifting buoy deployment on Lake St. Clair within the Great Lakes Waterway from August 12-15, 2002

Lake St. Clair is a 430 square mile lake between the state of Michigan and the province of Ontario, which forms part of the international boundary between the United States and Canada in the Great Lakes Basin. Lake St. Clair receives most of its inflow from Lake Huron through St. Clair River, which has an average flow of 182,000 cubic feet per second. The lake discharges to Detroit River, where it flows 32 miles to Lake Erie. Twelve drifting buoys were deployed on Lake St. Clair for 74 hours between August 12-15, 2002 to help investigate flow circulation patterns as part of a source water assessment study of the susceptibility of public water intakes. The buoys contained global positioning system (GPS) receivers to track their movements. Buoys were released in a transect between tethered buoys marking an 800-foot wide navigational channel in the north-central part of the lake just downstream of St. Clair River, and about 15.5 miles northeast of Detroit River. In addition, an acoustic Doppler current profiler (ADCP) was used to measure velocity profiles in a grid of 41 points that spanned the area through which the buoys drifted. Computer animations, which can be viewed through the Internet, were developed to help visualize the results of the buoy deployments and ADCP measurements.

Michigan↗
USGS2002

A two-dimensional hydrodynamic model of the St. Clair-Detroit River waterway in the Great Lakes basin

The St. Clair-Detroit River waterway connects Lake Huron with Lake Erie in the Great Lakes basin to form part of the international boundary between the United States and Canada. A two-dimensional hydrodynamic model is developed to compute flow velocities and water levels as part of a source water assessment of public water intakes. The model, which uses the generalized finite-element code RMA2, discretizes the waterway into a mesh formed by 13,783 quadratic elements defined by 42,936 nodes. Seven steady-state scenarios are used to calibrate the model by adjusting parameters associated with channel roughness in 25 material zones. An inverse modeling code is used to systematically adjust model parameters and to determine their associated uncertainty by use of nonlinear regression. Calibration results show close agreement between simulated and expected flows in major channels and water levels at gaging stations. Sensitivity analyses describe the amount of information available to estimate individual model parameters, and quantify the utility of flow measurements at selected cross sections and water-level measurements at gaging stations. Further data collection, model calibration analysis, and grid refinements are planned to assess and enhance two-dimensional flow simulation capabilities describing the horizontal flow distributions in St. Clair and Detroit Rivers and circulation patterns in Lake St. Clair.

St. Clair-Detroit River waterway↗
USGS2002

Polar Bears

Polar bears ( Ursus maritimus ) are hunted throughout most of their range. In addition to hunting polar bears of the Beaufort Sea region are exposed to mineral and petroleum extraction and related human activities such as shipping road-building, and seismic testing (Stirling 1990). Little was known at the start of this project about how polar bears move about in their environment, and although it was understood that many bears travel across political borders, the boundaries of populations had not been delineated (Amstrup 1986, Amstrup et al. 1986, Amstrup and DeMaster 1988, Garner et al. 1994, Amstrup 1995, Amstrup et al. 1995, Amstrup 2000). As human populations increase and demands for polar bears and other arctic resources escalate, managers must know the sizes and distributions of the polar bear populations. Resource managers also need reliable estimates of breeding rates, reproductive intervals, litter sizes, and survival of young and adults. Our objectives for this research were 1) to determine the seasonal and annual movements of polar bears in the Beaufort Sea, 2) to define the boundaries of the population(s) using this region, 3) to determine the size and status of the Beaufort Sea polar bear population, and 4) to establish reproduction and survival rates (Amstrup 2000).

Alaska, Northwest Territories, Yukon Territory↗
USGS2002

Snow geese

Part of the coastal plain of the Arctic National Wildlife Refuge, Alaska, is used as an autumn staging area by lesser snow geese ( Chen caerulescens caerulescens ) from the Western Canadian Arctic population (hereafter called the Western Arctic population). There were approximately 200,000 breeding adults in the Western Arctic population through the mid-1980s (Johnson and Herter 1989), but the population has recently increased to about 500,000 breeding adults (Kerbes et al. 1999). Early in their autumn migration, adult and juvenile snow geese from the Western Arctic population feed intensively while staging on the Beaufort Sea coastal plain in Canada and Alaska to build fat reserves needed for migration. Aerial censuses from 1973 to 1985 indicated that up to 600,000 adult and juvenile snow geese used the coastal plain for 2-4 weeks in late August until mid-September (Oates et al. 1987). We studied annual variation in numbers and spatial distribution of snow geese that staged on the coastal plain of the Arctic Refuge.

Alaska, Northwest Territories, Yukon Territory↗
USGS2002

Forage quantity and quality

The Porcupine caribou herd has traditionally used the coastal plain of the Arctic National Wildlife Refuge, Alaska, for calving. Availability of nutritious forage has been hypothesized as one of the reasons the Porcupine caribou herd migrates hundreds of kilometers to reach the coastal plain for calving (Kuropat and Bryant 1980, Russell et al. 1993). Forage quantity and quality and the chronology of snowmelt (which determines availability and phenological stages of forage) have been suggested as important habitat attributes that lead calving caribou to select one area over another (Lent 1980, White and Trudell 1980, Eastland et al. 1989). A major question when considering the impact of petroleum development is whether potential displacement of the caribou from the 1002 Area to alternate calving habitat will limit access to high quantity and quality forage. Our study had the following objectives: 1) quantify snowmelt patterns by area; 2) quantify relationships among phenology, biomass, and nutrient content of principal forage species by vegetation type; and 3) determine if traditional concentrated calving areas differ from adjacent areas with lower calving densities in terms of vegetation characteristics.

Alaska, Northwest Territories, Yukon Territory↗
USGS2002

Predators

Calving caribou ( Rangifer tarandus ) of the Central Arctic herd, Alaska, have avoided the infrastructure associated with the complex of petroleum development areas from Prudhoe Bay to Kuparuk (Cameron et al. 1992, Nellemann and Cameron 1998, and Section 4 of this document). Calving females of the Porcupine caribou herd may similarly avoid any oil field roads and pipelines developed in areas traditionally used during the calving and post-calving periods. This may displace the caribou females and calves to areas east and south of the 1002 Area of the Arctic National Wildlife Refuge. Increased calf mortality could occur if calving caribou are displaced into areas that have a higher density of predators, higher rates of predation, or where a higher proportion of the predators regularly use caribou as a food source (Whitten et al. 1992). Our study assessed predation risks to caribou calving in the 1002 Area versus calving in potential displacement areas. Due to funding constraints, our research focused on grizzly bears ( Ursus arctos ), with wolves (Camus lupus) and golden eagles ( Aquila chrysaetos ) receiving only cursory attention. Our research objectives were 1) to compare relative abundance of predators within the 1002 Area with that in adjacent peripheral areas, 2) to determine factors affecting predator abundance on the calving grounds, and 3) to quantify the use of caribou as a food source for predators and the importance of caribou to the productivity of predator populations using the coastal plain of the Arctic National Wildlife Refuge.

Alaska, Northwest Territories, Yukon Territory↗
USGS2002

Introduction

The Arctic National Wildlife Refuge in northeastern Alaska is one of 16 refuges in Alaska and 539 refuges nationwide within the National Wildlife Refuge System administered by the U.S. Fish and Wildlife Service. First established as the Arctic National Wildlife Range in 1960 by Public Land Order 2214, it initially had a three-fold purpose to preserve unique wildlife, wilderness, and recreation values on 8.9 million acres. In 1980, the Arctic National Wildlife Range was expanded to the southwest and renamed the Arctic National Wildlife Refuge (also called the Arctic Refuge in this report) when the U.S. Congress passed the Alaska National Interest Lands Conservation Act (ANILCA), Public Law 96-487 (94 Stat. 2371). This legislation also designated almost all of the original Arctic National Wildlife Range as wilderness, and it directed the Secretary of the Interior to conduct studies evaluating both the biological resources and the potential petroleum reserves of 1.5 million acres (titled the 1002 Area) on the coastal plain of the Arctic Refuge. In April 1982, the Arctic Refuge staff completed a report summarizing the then current state of knowledge on the fish, wildlife, and their habitats present on the coastal plain of the Arctic Refuge (U.S. Fish and Wildlife Service 1982). From 1982 to 1985, field investigations of biological resources of the 1002 Area were carried out by a number of investigators, and annual reports summarized the results (Garner and Reynolds 1983, 1984, 1985, 1986, 1987). These reports and other resources were used to prepare a Department of the Interior report to Congress: Arctic National Wildlife Refuge, Alaska Coastal Plain Resource Assessment - Report and Recommendation to the Congress of the United States and Final Environmental Impact Satement (Clough et al., 1987).

Alaska, Northwest Territories, Yukon Territory↗