Influence of energy-related produced wastewaters on the microbial community of wetland sediment , water, and amphibian skin

To inform responsible energy development, it is important to understand the ecological effects of contamination events. Wastewaters from oil and gas extraction often contain high concentrations of sodium chloride (NaCl) and heavy metals (e.g., strontium and vanadium), but studies of their influence on microbial communities are limited. We sampled water, sediment, and larval amphibian skin (four species) microbiomes across a gradient of contamination (0.04 to 17500 mg/L Cl) in a large energy production area of North America. NaCl concentrations affected the similarity among microbiomes of water, sediment, and amphibian skin, but not the diversity or richness of water and skin microbiomes. Strontium concentrations were associated with lower diversity and richness of sediment microbial communities. Amphibian microbiomes were similar to those of water, but not sediment, and sediment microbiomes were similar to those of water. Species identity was the strongest predictor of amphibian microbiomes; frog microbiomes were similar but differed from that of the salamander, whose microbiome had the lowest richness and diversity. Understanding whether effects of wastewaters on microbial communities also influences their ecosystem function will be an important next step. Our study provides novel insight into associations among different wetland microbial communities and effects of wastewaters from energy production.