Publications

No abstract available.

The Red River of the North drainage basin (herein referred to as Red River Basin) within the United States is a study unit under the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) program. The overall goals of this program, initiated to better define the status and trends of the Nation’s water quality, are to address regional and national water-quality issues in a national

No abstract available.

Four month-long field experiments investigated movements of water and solutes through unsaturated sand plains near Princeton, Minnesota, and Oakes, North Dakota. Atrazine and bromide were applied to bare soils and soils planted with corn. The field plots were irrigated according to local farming practices. At the end of each experiment, unsaturated soils were analyzed for atrazine and bromide conc

Malachite green, an effective antifungal therapeutant used in fish culture, is a known teratogen. We developed a method to simultaneously detect both the chromatic and leuco forms of malachite green residues in the eggs, fry, and adult muscle tissue of rainbow trout (Oncorhynchus mykiss). Homogenates of these tissues were fortified with [14C] malachite green chloride and extracted with 1% (v/v) ac

Acute toxicity tests were conducted to determine (a) the individual and interactive effects of water temperature (7, 12, 17°C), pH (6 5, 7 5, 8 5, 9 5), and time on the toxicity of terbufos, trichlorfon, 4 nitrophenol, and 2,4-dinitrophenol to rainbow trout (Oncorhynchus mykiss) and the amphipod Gammarus pseudohmnaeus, and (b) the individual and interactive effects of water temperature and pH on c

A liquid chromatographic method is described for the determination of sarafloxacin hydrochloride residues in channel catfish (Ictalurus punctatus) fillets. Sarafloxacin was extracted from fillet tissue with acetonitrile–water (1+1). The extract was centrifuged and the supernatant was partitioned with hexane. The aqueous fraction was filtered through a 0.45 μm filter and evaporated to dryness. The

Toxicity tests (28-d early-life-stage) were conducted to determine the effects of nine combinations of salinity (15, 20, 25 ppt) and temperature (22, 27, 32°C) on the toxicity of 2,4-dinitrophenol (2,4-DNP) and 4-nitrophenol (4-NP) to sheepshead minnows (Cyprinodon variegatus). The highest tested concentration having no observed effect (NOEC) on mortality and growth was derived weekly. The NOECs a

Early-life-stage (ELS) toxicity tests were conducted to determine the effect of selected water temperatures on the toxicity of 4-nitrophenol and 2,4-dinitrophenol to rainbow trout (Oncorhynchus mykiss). NOECs were determined for growth and mortality at selected time intervals and water temperatures of 7, 12, and 17°C. As tests progressed, NOECs leveled to constant time-independent values that were

Lake Number, LN, values are shown to be quantitative indicators of deep mixing in lakes and reservoirs that can be used to estimate changes in deep water dissolved oxygen (DO) concentrations. LN is a dimensionless parameter defined as the ratio of the moments about the center of volume of the water body, of the stabilizing force of gravity associated with density stratification to the destabilizin

The toxicities of two industrial chemicals (4-nitrophenol and 2,4-dinitrophenol) and two organophosphate insecticides (terbufos and trichlorfon) to juvenile grass shrimp (Palaemonetes spp.) and sheepshead minnows (Cyprinodon vanegatus) were determined by static, 96-h toxicity tests in a factorial design with 12 combinations of salinity and temperature (15, 20, 25, 30ppt x 17, 22, 27°C). Concentrat

We examined sublethal responses of juvenile bluegills Lepomis macrochirus to aqueous cadmium in two 28-d tests (test I, 0.0-8.4 μg Cd per liter; test II, 0.0-32.3 μg Cd per liter) in an intermittent-flow diluter. The experimental design was completely randomized, with two replicates in each of eight treatments (seven Cd exposures and one water control with 25 fish per replicate). Cadmium did not a