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Response of periphyton fatty acid composition to supplemental flows in the upper Esopus Creek, Catskill Mountains, New York

January 7, 2016

Fatty acid analysis of periphyton is an emerging tool for assessing the condition of a stream ecosystem on the basis of its water quality. The study presented in this report was designed to test the hypothesis that periphyton communities have a fatty acid profile that can detect excessive turbidity and suspended sediment. The fatty acid composition of periphyton was assessed during two seasons upstream and downstream from an underground aqueduct that provides supplemental flows, which are a potential source of turbidity and suspended sediment on the upper Esopus Creek, New York. These data were compared with measurements of periphyton standing crop, diatom community structure and integrity, and basic water-quality parameters. Periphyton standing crop and diatom community integrity indicated little evidence of impairment from the supplemental flows. The relative abundances of two physiologically important fatty acids, γ-linolenic acid (18:3ω6) and eicosapentaenoic acid (20:5ω3), were significantly lower downstream from the supplemental flows and multivariate analyses of fatty acid profiles identified significant differences between sites upstream and downstream from the supplemental flows. Individual fatty acids and summary metrics, however, were not significantly correlated with turbidity or suspended sediment. Together, these results indicate that the supplemental flows may cause some measurable effects but they do not constitute a major disturbance to the periphyton community on the upper Esopus Creek. Fatty acid analysis may have potential as a tool for monitoring changes in periphyton nutritional composition that may reflect water quality and ecosystem health but needs to be further evaluated around a more definitive source of water-quality impairment.

Publication Year 2016
Title Response of periphyton fatty acid composition to supplemental flows in the upper Esopus Creek, Catskill Mountains, New York
DOI 10.3133/sir20155161
Authors Scott D. George, Anne G. Ernst, Barry P. Baldigo, Dale C. Honeyfield
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Scientific Investigations Report
Series Number 2015-5161
Index ID sir20155161
Record Source USGS Publications Warehouse
USGS Organization New York Water Science Center