Publications

To provide data for the Texas Source-Water Assessment and Protection Program, the U.S. Geological Survey conducted a synoptic survey of 48 public water-supply reservoirs and 174 public water-supply wells during 1999–2001. The surface-water samples were analyzed for volatile organic compounds and soluble pesticides. The ground-water samples were analyzed for volatile organic compounds and...

Peregrine falcons (Falco peregrinus) have been recorded nesting in Big Bend National Park, Texas, USA and other areas of the Chihuahuan Desert since the early 1900s. From 1993 to 1996, peregrine falcon productivity rates were very low and coincided with periods of low rainfall. However, low productivity also was suspected to be caused by environmental contaminants. To evaluate potential...

Dry Tortugas National Park, which includes Bush, Long, Loggerhead, Garden, and Bird Keys, is a cluster of islands and coral reefs approximately 112.9 km (70 miles) west of Key West, Florida (fig. 1). These islands were explored in 1513 by Ponce de León, who named them for the abundance of sea turtles, “tortugas,” and the lack of fresh water in the area. Historically, the Tortugas shoals...

The Neosho madtom, Noturus placidus, is a small catfish listed by the U. S. Fish and Wildlife Service as threatened. Little is known of its breeding biology and behavior because high turbidity and flow during its spawning season prevent direct observation in the field, and captive propagation has met with limited success. We held Neosho madtoms in laboratory aquaria in 1996 and 1998 to...

No abstract available at this time

The Upper Floridan aquifer is the principal source of water for domestic and agricultural use in the lower Apalachicola-Chattahoochee-Flint (ACF) River Basin. Recent drought and increased water use have made understanding surface- and ground-water relations a priority for water-resource managers in the region. From July 1999 through August 2000, less than normal precipitation reduced...

Polyhalogenated hydrocarbons have been implicated in the anomalous sexual differentiation of mammals and reptiles. Here, a temperature-sensitive turtle sex determination assay using the red-eared slider (Trachemys scripta elegans) was used to determine the estrogenic or antiestrogenic activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126)...

No abstract available.

In an effort to restore riverine wetlands along the Missouri River, the Missouri Department of Conservation constructed the 2,700-acre Eagle Bluffs Conservation Area. The primary water source for managing 1,200 wetland acres on the Eagle Bluffs Conservation Area is treated effluent received from a 91-acre constructed wastewater-treatment wetland operated by the city of Columbia, Missouri...

The U.S. Geological Survey developed a watershed model (Hydrological Simulation Program—FORTRAN) to simulate runoff and recharge and to estimate constituent loads in surface-water runoff in the Edwards aquifer recharge zone (outcrop) and catchment area in Bexar County, Texas. Rainfall and runoff data collected during 1970–98 from four gaged basins in the outcrop and catchment area were...

Cycling nutrient-enriched wastewater from holding ponds through natural, forested wetlands is a practice that municipal waste treatment managers are considering as a viable option for disposing of wastewater. In this wastewater cycling process, sewer effluent that has been circulated through aerated ponds is discharged into neighboring wetland systems. To understand how wastewater...

The Across Trophic Level System Simulation (ATLSS) Program of the U.S. Geological Survey has produced High-Resolution Hydrology and High-Resolution Topography models to provide high-resolution hydrologic data for the Greater Everglades landscape. Such hydrologic data is essential for describing the effect of hydrology on the important wildlife populations that are being modeled by the...