Contaminant subsidies to riparian food webs in Appalachian streams impacted by mountaintop removal coal mining

Environmental Science & Technology
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Abstract

Selenium is highly elevated in Appalachian streams and stream organisms that receive alkaline mine drainage from mountaintop removal coal mining compared to unimpacted streams in the region. Adult aquatic insects can be important vectors of waterborne contaminants to riparian food webs, yet pathways of Se transport and exposure of riparian organisms are poorly characterized. We investigated Se concentrations in stream and riparian organisms to determine whether mining extent increased Se uptake in stream biofilms and insects and if these insects were effective Se biovectors to riparian spiders. Biofilm Se concentration increased (p = 0.006) with mining extent, reaching a maximum value of 16.5 μg/g of dw. Insect and spider Se increased with biofilm Se (p = 0.004, p = 0.003), reaching 95 and 26 μg/g of dw, respectively, in mining-impacted streams. Adult insect biomass was not related to mining extent or Se concentrations in biofilm. Even though Se concentrations in aquatic insects were significantly and positively related to mining extent, aquatic insect Se flux was not associated with mining extent because the mass of emerging insects did not change appreciably over the mining gradient. Insect and spider Se concentrations were among the highest reported in the literature, regularly exceeding the bird Se dietary risk threshold of 5 μg/g of dw. Risks of Se exposure and toxicity related to mining are thus not constrained to aquatic systems but extend to terrestrial habitats and food webs.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Contaminant subsidies to riparian food webs in Appalachian streams impacted by mountaintop removal coal mining
Series title Environmental Science & Technology
DOI 10.1021/acs.est.9b05907
Volume 54
Issue 7
Year Published 2020
Language English
Publisher American Chemical Society
Contributing office(s) Columbia Environmental Research Center
Description 9 p.
First page 3951
Last page 3959
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