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Seasonal Loading and Concentration Patterns for Fecal Bacteroidales qPCR Markers and Relationships to Water Quality Parameters at Baseflow

Stallard, M. A., Winesett, S., Scopel, M., Bruce, M., Bailey, F. C.
Water, air, and soil pollution 2019 v.230 no.2 pp. 36
Bacteroidales, animals, base flow, dissolved oxygen, environmental factors, fecal bacteria, intestines, monitoring, pollution, quantitative polymerase chain reaction, ribosomal RNA, seasonal variation, spring, stakeholders, streams, summer, surface water, temperature, total suspended solids, water quality, watersheds, Tennessee
Bacteria belonging to the Order Bacteroidales predominate the intestines of warm-blooded animals, and monitoring of these bacteria can indicate fecal pollution impacts to a waterbody. Differences in seasonal concentrations and loadings for Bacteroidales and their relationship with physicochemical water parameters were investigated in temperate, inland streams. Seasonal samples (n = 321) were collected during baseflow in three central Tennessee, USA, watersheds. To estimate total fecal bacteria in receiving streams, general Bacteroidales 16S rRNA gene targets were analyzed by quantitative PCR and reported as concentration and loadings for individual and combined watersheds. In most cases, Bacteroidales marker concentrations were highest during spring/summer and loading values were highest in the spring. Bacteroidales concentrations were positively correlated with temperature and total suspended solids and negatively with dissolved oxygen, while no consistent correlations were found between loadings and abiotic factors. Temperature, total suspended solids, and dissolved oxygen are likely drivers influencing seasonal patterns for Bacteroidales concentrations. Researchers and water quality stakeholders should carefully consider measurement type (concentration versus loading), season, and water quality parameters as elements that could impact results when developing fecal monitoring projects.