The Tennessee Valley Authority Kingston coal ash spill in December 2008 deposited approximately 4.1 million m(3) of fly ash and bottom ash into the Emory and Clinch River system (Harriman, Tennessee, U.S.A.). The objective of this study was to investigate the impact of the ash on surface water and sediment quality over an eighteen month period after the spill, with a specific focus on mercury a...

Escherichia coli bacteria are commonly used as indicator organisms to designate of impaired surface waters and to guide the design of management practices to prevent fecal contamination of water. Stream sediments are known to serve as a reservoir and potential source of fecal bacteria (E. coli) for stream water. In agricultural watersheds, substantial numbers of E. coli may reach surface waters...

Large amounts of rubber particles are dispersed into the environment due to tire wear. The rubber contains a wide range of chemicals, including several of environmental concern. The purpose of this thesis, which is based on six papers [I–VI], was to assess the ecotoxicological hazard and risk associated with tire wear particles, with a main focus on the aquatic environment. A method was develop...

Coral reefs are globally important marine ecosystems as sites of high biotic diversity. Reef flat sediments are reasonably homogeneous in composition. This substratum is subject to gradients in water motion, grazing pressure and benthic productivity. This study used DNA fingerprinting techniques, automated rRNA intergenic spacer analysis (ARISA), and terminal restriction fragment length polymor...

Oxygen minimum zones (OMZs) that impinge on continental margins favor the release of phosphorus (P) from the sediments to the water column, enhancing primary productivity and the maintenance or expansion of low-oxygen waters. A comprehensive field program in the Peruvian OMZ was undertaken to identify the sources of benthic P at six stations, including the analysis of particles from the water c...

Experiments on the entrainment of surface sediments around polychaete tubes at natural and manipulated densities were conducted in a recirculating seawater flume. Intact cores with either 0 or 8 Diopatra cuprea tubes per 0.01 m* plus associated assemblages were collected in the field. Sediments which contained D. cuprea tubes had natural macrofaunal densities > 5 x those of sediments without tu...

Proteinaceous material usually accounts for much of the total nitrogen and organic carbon in marine sediments. Thus, decomposition of protein is frequently investigated as a measure of labile organic matter turnover. The fraction of protein that escapes remineralization to CO2 undergoes transformations that may reflect pathways of preservation in sedimentary environments. We analyzed the molecu...

Experiments were undertaken to examine the key variables affecting metal release and sequestration processes in marine sediments with metal concentrations in sediments reaching up to 86, 240, 700, and 3000 mg kg(-1) (dry weight) for Cd, Cu, Pb and Zn, respectively. The metal release and sequestration rates were affected to a much greater extent by changes in overlying water pH (5.5-8.0) and sed...