Effects of hardness and alkalinity in culture and test waters on reproduction of Ceriodaphnia dubia.

Ceriodaphnia dubia were cultured in four reconstituted water formulations with hardness and alkalinity concentrations ranging from soft to the moderately hard water that is required by whole-effluent toxicity (WET) testing methods for culturing test organisms. The effects of these culture formulations alone and in combination with two levels of Cl-, SO4(2-), and HCO3- on reproduction of C. dubia were evaluated with the standard three-brood test.

Potential impact of Dare County landfills on Alligator River National Wildlife Refuge.

Runoff of leachate from East Lake and Dare County Construction and Demolition Debris landfills has the potential to impact wildlife resources at Alligator River National Wildlife Refuge, Dare and Hyde Counties, North Carolina. Sediment quality of samples collected in August 2000 at 14 locations down-gradient from the landfills was assessed by measuring metal and organic contaminants in the sediments, chronic toxicity of solid-phase sediment (28-d static-renewal exposures; survival and growth as test endpoints) and acute toxicity of sediment porewater (96-h static exposures) to Hyalella azteca (Crustacea: Amphipoda). In addition, contaminant bioaccumulation from 4 sediments was determined using 28-d exposures of Lumbriculus variegatus (freshwater oligochaete).

Combined use of Rapid Bioassessment Protocols and Sediment Quality Triad to assess stream quality.

Physical, chemical and biological conditions at five stations on a small southeastern stream were evaluated using the Rapid Bioassessment Protocols (RBP) and the Sediment Quality Triad (SQT) to assess potential biological impacts of a municipal wastewater treatment facility (WWTF) on downstream resources. Physical habitat, benthic macroinvertebrates and fish assemblages were impaired at Stations 1 and 2 (upstream of the WWTF), suggesting that the degraded physical habitat was adversely impacting the fish and benthic populations. The SQT also demonstrated that Stations 1 and 2 were degraded, but the factors responsible for the impaired conditions were attributed to the elevated concentrations of polycylclic aromatic hydrocarbons (PAHs) and metals (Mn, Pb) in the sediments.

Atmospheric lead deposition to Okefenokee Swamp, Georgia, USA.

Contamination of the environment from atmospheric deposition during the twentieth century is pervasive even in areas ostensibly considered pristine or remote from point sources. In this study, Pb concentrations in a 210Pb-dated peat core collected from the Okefenokee Swamp, GA were used to assess historical contaminant input via atmospheric deposition. Lead isotope ratios were determined by dynamic reaction cell ICP-MS (DRC-ICP-MS).