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On December 22, 2008 a dike containing coal fly ash from the Tennessee Valley Authority Kingston Fossil Plant near Kingston Tennessee USA failed and resulted in the largest coal ash spill in U.S. history. Coal ash, a by-product of coal combustion, is known to contain multiple contaminants of concern, including arsenic and selenium. The purpose of this study was to investigate species differences in the bioaccumulation of arsenic and selenium and potential factors contributing to these differences (i.e., trophic dynamics and gut pH) in the vicinity of the Kingston coal ash spill. Elevated levels of arsenic and selenium were observed in various tissues of largemouth bass, white crappie, bluegill and redear sunfish from sites associated with the Kingston coal ash spill. Highest concentrations of selenium were found in redear sunfish with liver concentrations as high as 24.83mg/kg dry weight and ovary concentrations up to 10.40mg/kg dry weight at coal ash-associated sites. Investigations into the gut pH and trophic dynamics of redear sunfish and bluegill demonstrated a large difference in the gut physiology between these two species. Redear sunfish stomach and intestinal pH was found to be 1.1 and 0.16 pH units higher than in bluegill, respectively. In addition, fish from coal ash-associated sites showed enrichment differences (15N and 13C) compared to no ash sites, indicating differences in food web dynamics between sites. These results imply the incorporation of coal ash-associated compounds into local food webs and/or a shift in diet at ash sites compared to the no ash reference sites. Based on these results, further investigation into a broader food web at ash-associated sites is warranted. [Copyright &y& Elsevier]

Urbanization has been linked to increased concentrations of polycyclic aromatic hydrocarbons in natural waterways. This study was designed to examine the impact of urbanization and a wastewater treatment plant by investigating the impact on field-collected bluegill (Lepomis macrochirus). Results show a significant increase in DNA strand breaks in blood cells (comet assay) linked to urbanization and a reduction in DNA strand breaks downstream of the WWTP, likely the result of dilution. A laboratory study exposing L. macrochirus to the known mutagen, methyl methanesulfonate, was performed to validate the comet assay endpoints in this species. Results of the laboratory study showed that the comet assay endpoints of tail length and tail extent moment responded in a dose- and time-dependent manner. Habitat quality assessments, along with chemical concentrations of polycyclic hydrocarbons in sediments showed that habitat quality between all sites were similar and that hydrocarbons likely contributed to the DNA strand breaks observed. [Copyright &y& Elsevier]

The article presents a stream subsidy research which looks into the relationships between the aquatic resource utilization and the contaminant exposure of the riparian predators, like spiders and herptiles, in a polychlorinated biphenyls contaminated stream in the U.S. According to the study, the energy subsidy of the riparian has a huge impact on the behavior, production, as well as diversity of the species. With this, identifying and validating the ecological tracers of the stream subsidy relevant to the stream conditions are believed necessary.