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Biological invasions are a widespread and significant component of human-caused global environmental change. The extent of invasions of oceanic islands, and their consequences for native biological diversity, have long been recognized. However, invasions of continental regions also are substantial. For example, more than 2,000 species of alien plants are established...

The Long Term Resource Monitoring Program (LTRMP) completed 2,653 collections of fishes from stratified random and permanently fixed sampling locations in six study reaches of the Upper Mississippi River System during 1994. Collection methods included day and night electrofishing, hoop netting, fyke netting (two net sizes), gill netting, seining,...

Planar PCB congeners are embryotoxic and teratogenic to birds including American kestrels. The developmental toxicity of 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) was studied in the posthatching kestrel as a model for the eagle. Nestlings were dosed orally for 10 days with 5 μl/g body weight of corn oil (controls) or the planar...

Lesser scaup (Aythya affinis) winter in the Grand Calumet River—Indiana Harbor Canal (GCR-IHC) drainage into southern Lake Michigan, a polluted oasis in the highly urban and industrial corridor of northern Illinois and Indiana. The GCR-IHC is an important wintering area for...

Our current understanding of wetlands is insufficient to assess the effects of past and future wetland loss. While knowledge of wetland hydrology is crucial, groundwater flows are often neglected or uncertain. In this paper, groundwater inflows were estimated in wetlands in southwestern Wisconsin using traditional Darcy's law calculations and three...

The ability to assess quickly the potential for scour at a bridge site, to evaluate those bridges with the greatest potential for significant amounts of scour, and to then identify scour-critical structures is important for public protection and bridge maintenance planning. A bridge-scour assessment information form was developed for collecting...

The electrical output of electrofishing equipment is commonly standardized by using either constant voltage or constant amperage, However, simplified circuit and wave theories of electricity suggest that standardization of power (wattage) available for transfer from water to fish may be critical for effective standardization of electrofishing. Electrofishing with standardized power...

Populations of many North American land-birds, including forest-inhabiting species that winter in the Neotropics, seem to be declining (Robbins et al. 1989; Terborgh 1989). These declines have been identified through broad-scale, long-term survey programs that identify changes in abundance pf species, but provide little information about causes of changes in...

Efforts to restore lake trout (Salvelinus namaycush) in Lake Huron after their collapse in the 1940s were underway in the early 1970s with completion of the first round oflampricide applications in tributary streams and the stocking of several genotypes. We assess...

We incubated lake trout (Salvelinus namaycush) eggs over winter at shallow (10 m) and deep locations (20 m) on Gull Island Shoal, Lake Superior; at a shallow-water (10 m) site off the mainland (Bark Point); and in flowing Great Lakes water at two laboratories. Survival to hatch was significantly higher...

Much of the Edwards-Trinity aquifer system contains freshwater, but sizable parts contain marginally fresh or slightly saline water. The predominant water type in the aquifer system is calcium bicarbonate; however, one of seven other hydrochemical facies characterizes the water in places. The median dissolved-solids concentration of water samples from the...

In 1991 the Trinity River Basin National Water-Quality Assessment (NAWQA) will include assessments of surface-water and ground-water quality. Initial efforts have focused on identifying water-quality issues in the basin and on the environmental factors underlying those issues. Physical characteristics described include climate, geology, soils, vegetation, physiography, and hydrology. Cultural characteristics...

Ever since Gregory's work at the turn of the century, the extensional structures extending through central Kenya have been recognized as the classic example of a continental rift zone. Because of the scale and variety of rift features present, this locality has fascinated geologists and geophysicists since...

Field measurements to investigate the origin and growth of mesoscale gravel bed forms in deep flows were made in the North Fork Toutle River, Washington. Sonar observations of the gravel streambed at a stationary point were recorded during two storm flows in December 1989 and January 1990 with concurrent bed...

The otoliths of 676,000 sac fry of lake trout Salvelinus namaycush in 1986, and of 1,100,000 in 1987, were marked by daily manipulation of water temperature. The fish were stocked into Lake Huron in the spring. Otolith marks consisted of groups of daily growth rings accentuated into recognizable patterns by...

Corrosive groundwater, which has been linked to trace-metal leaching from plumbing materials in Europe and the United States , has been identified in the Coastal Plain of New Jersey. The corrosiveness of groundwater in the Kirkwood-Cohansey aquifer system in New Jersey has been estimated by calculating values for the Aggressive...

No abstract available. ...

A bioassay procedure to assess habitat quality was tested on Port Austin reef in southern Lake Huron, a spawning area of lake trout Salvelinus namaycush. In 1986, Plexiglas incubators filled with fertilized lake trout eggs were buried by scuba divers in rock rubble at two sites. The incubators then were attached...

During 1986 and 1987, migrating bed forms composed of coarse sand and fine gravel (d50=1.8 to 9.1 mm) were documented in the North Fork Toutle River at Kid Valley, Washington, at flow velocities ranging from 1.6 to 3.4 m s−1 and depths of 0.8 to 2.2 m. The bed forms (predominantly...

Geographic Information Systems (GIS) technologies are being used in three neutral resource management studies of Mobile Bay, AL. Each study is briefly discussed. In the first, the GIS was used to analyze wetland habitat changes in the bay over a 25-year period. In the second, cartographic modeling techniques are being...

Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of...

No abstract available....

No abstract available....

This preliminary map is the first product of the ground-water resources study of Towner County, which has an area of 1,049 mi2 (2,717 km2) in north-central North Dakota (see location map).  The study is part of a statewide program to determine the...