Invasive crayfish as vectors of mercury in freshwater food webs of the Pacific Northwest

Environmental Toxicology and Chemistry
By: , and 

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Abstract

Invasive species are important drivers of environmental change in aquatic ecosystems and can alter habitat characteristics, community composition, and ecosystem energetics. Such changes have important implications for many ecosystem processes, including the bioaccumulation and biomagnification of contaminants through food webs. Mercury concentrations were measured in 2 nonnative and 1 native crayfish species from western Oregon (USA). Nonnative red swamp crayfish had mercury concentrations similar to those in native signal crayfish (0.29 ± 0.05 µg/g dry wt and 0.36 ± 0.06 µg/g dry wt, respectively), whereas the nonnative ringed crayfish had lower mercury concentrations (0.10 ± 0.02 µg/g dry wt) than either of the other species. The mean energy content of muscle was similar between the native signal crayfish and nonnative ringed crayfish but was significantly higher in the nonnative red swamp crayfish. Across species, mercury concentrations were negatively correlated with energy density. Such energetic differences could exacerbate changes in mercury transfer through trophic pathways of food webs, especially via alterations to the growth dynamics of consumers. Thus, it is important to consider the role of energy content in determining effective mercury exposure even when mercury concentrations on a per-unit mass basis do not differ between species.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Invasive crayfish as vectors of mercury in freshwater food webs of the Pacific Northwest
Series title Environmental Toxicology and Chemistry
DOI 10.1002/etc.2727
Volume 33
Issue 11
Year Published 2014
Language English
Publisher Elsevier
Contributing office(s) Forest and Rangeland Ecosystem Science Center, Contaminant Biology Program
Description 7 p.
First page 2639
Last page 2645
Country United States
State Oregon