Publications

Boron (B), molybdenum (Mo), and selenium (Se) were measured in water, sediment, particulate organic detritus, and in various biota—filamentous algae, net plankton, macroinvertebrates, and fishes—to determine if concentrations were elevated from exposure to agricultural subsurface (tile) drainage during the spring and fall 1987, in the San Joaquin River, California. Concentrations of B...

No abstract available.

The acute toxicities of technical-grade bromoxynil octanoate (BO) and two commercial formulations, Buctril® and Bronate®, to 24-h-old neonate Daphnia magna (Straus) were determined in soft, hard, and oligosaline water. In addition, effects of life stage, feeding, aging the herbicide, and exposure duration on BO toxicity to daphnids were investigated. Regardless of formulation, life stage...

The environment has become contaminated with complex mixtures of planar, chlorinated hydrocarbons (PCHs) such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and structurally similar compounds. Because the potencies of individual congeners to cause the same adverse effects vary greatly and the relative as well as...

The use of dilutions has been the foundation of our approach for assessing contaminated water, and accordingly, it may be important to establish similar or parallel approaches for sediment dilutions. Test organism responses to dilution gradients can identify the degree of necessary sediment alteration to reduce the toxicity. Using whole sediment dilutions to represent the complex...

A chlor-alkali plant in Brunswick, Georgia, USA, discharged >2 kg mercury/d into a tributary of the Turtle River-Brunswick Estuary from 1966 to 1971. Mercury concentrations in sediments collected in 1989 along the tributary near the chlor-alkali plant ranged from 1 to 27 μg/g (dry weight), with the highest concentrations found in surface (0–8 cm) sediments of subtidal zones in the...

Aquatic mesocosm studies are being used to refute a presumption of risk derived from laboratory toxicity tests conducted under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Mesocosm studies incorporate many biological, chemical and physical characteristics of natural ecosystems. Hence, they serve as realistic surrogates of natural ecosystems and allow tests of...

No abstract available.

Data from several sources were collated and analyzed by correlation, regression, and principal components analysis to define surrrogate variables for use in the brook trout (Salvelinus fontinalis) habitat suitability index (HSI) model, and to evaluate the applicability of the model for assessing habitat in high elevation streams of the southern Blue Ridge Province (SBRP). In all data...

Juvenile bluegill (Lepomis macrochirus) were exposed to waterborne selenium as a 6:1 mixture of selenate to selenite (as Se) for 60 d and to dietary seleno-l-methionine for 90 d. Measured concentrations of total selenium in the waterborne exposure ranged from 0.16 to 2.8 mg/l, and concentrations of seleno-l-methionine in the test diet ranged from 2.3 to 25.0 mg/kg wet weight. Mortality...

In the 2 years that followed the 100-year flood incident of September 1986 in the Saginaw River/Bay ecosystem, the reproduction of Caspian terns collapsed and then slowly recovered. Egg viability and fledging rates of hatched chicks were drastically depressed in 1987 and 1988. Eggs from clutches laid later in the year were less viable and chicks hatched from these eggs displayed wasting...

The activity of the enzyme δ-aminolevulinic acid dehydratase (ALA-D) in erythrocytes has long been used as a biomarker of lead exposure in humans and waterfowl and, more recently, in fishes. The assay was tested for ALA-D activity in fishes from streams affected by lead in combination with other metals from lead-zinc mining and related activities. Fishes (mostly catostomids) were...