Chemical contaminants in water and sediment near fish nesting sites in the Potomac River basin: determining potential exposures to smallmouth bass (Micropterus dolomieu)

Science of the Total Environment
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Abstract

The Potomac River basin is an area where a high prevalence of abnormalities such as testicular oocytes (TO), skin lesions, and mortality has been observed in smallmouth bass (SMB, Micropterus dolomieu). Previous research documented a variety of chemicals in regional streams, implicating chemical exposure as one plausible explanation for these biological effects. Six stream sites in the Potomac basin (and one out-of-basin reference site) were sampled to provide an assessment of chemicals in these streams. Potential early life-stage exposure to chemicals detected was assessed by collecting samples in and around SMB nesting areas. Target chemicals included those known to be associated with important agricultural and municipal wastewater sources in the Potomac basin. The prevalence and severity of TO in SMB were also measured to determine potential relations between chemistry and biological effects. A total of 39 chemicals were detected at least once in the discrete-water samples, with atrazine, caffeine, deethylatrazine, simazine, and iso-chlorotetracycline being most frequently detected. Of the most frequently detected chemicals, only caffeine was detected in water from the reference site. No biogenic hormones/sterols were detected in the discrete-water samples. In contrast, 100 chemicals (including six biogenic hormones/sterols) were found in a least one passive-water sample, with 25 being detected at all such samples. In addition, 46 chemicals (including seven biogenic hormones/sterols) were found in the bed-sediment samples, with caffeine, cholesterol, indole, para-cresol, and sitosterol detected in all such samples. The number of herbicides detected in discrete-water samples per site had a significant positive relation to TOrank (a nonparametric indicator of TO), with significant positive relations between TOrank and atrazine concentrations in discrete-water samples and to total hormone/sterol concentration in bed-sediment samples. Such significant correlations do not necessarily imply causation, as these chemical compositions and concentrations likely do not adequately reflect total SMB exposure history, particularly during critical life stages.

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Publication type Article
Publication Subtype Journal Article
Title Chemical contaminants in water and sediment near fish nesting sites in the Potomac River basin: determining potential exposures to smallmouth bass (Micropterus dolomieu)
Series title Science of the Total Environment
DOI 10.1016/j.scitotenv.2012.09.063
Volume 443
Year Published 2013
Language English
Publisher Elsevier
Publisher location Amsterdam, Netherlands
Contributing office(s) Iowa Water Science Center, National Water Quality Laboratory
Description 17 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Science of the Total Environment
First page 700
Last page 716
Country United States
Other Geospatial Potomac River Basin
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