High Anthropogenic Organic Matter Inputs during a Festival Increase River Heterotrophy and Refractory Carbon Load

Abstract

Streams and rivers metabolize dissolved organic matter (DOM). Although most DOM compounds originate from natural sources, recreational use of rivers increasingly introduces chemically distinct anthropogenic DOM. So far, the ecological impact of this DOM source is not well understood. Here, we show that a large music festival held adjacent to the Traisen River in Austria increased the river’s dissolved organic carbon (DOC) concentration from 1.6 to 2.1 mg L –1 and stream ecosystem respiration from −3.2 to −4.5 mg L –1 . The DOC increase was not detected by sensors continuously logging absorbance spectra, thereby challenging their applicability for monitoring. However, the fluorescence intensity doubled during the festival. Using parallel factor analysis, we were able to assign the increase in fluorescence intensity to the chemically stable UV-B filter phenylbenzimidazole sulfonic acid, indicating organic compounds in sunscreen and other personal care products as sources of elevated DOC. This observation was confirmed by liquid chromatography coupled with mass spectrometry. The elevated respiration is probably fueled by anthropogenic DOM contained in beer and/or urine. We conclude that intense recreational use of running waters transiently increases the anthropogenic DOM load into stream ecosystems and alters the fluvial metabolism. We further propose that chemically distinct, manmade DOM extends the natural range of DOM decomposition rates in fluvial ecosystems.

Synthetic and biological surfactant effects on freshwater biofilm community composition and metabolic activity

“…There is a growing body of evidence that anthropogenic trace contaminants, and contaminants of emerging concern (CECs), such as pharmaceuticals, herbicides, and antimicrobial agents can have major impacts upon the composition and functioning of aquatic microbial communities (Rosi-Marshall et al 2013;Argudo et al 2020;Harjung et al 2020;McClean and Hunter 2020;Ke et al 2020;Kusi et al 2020). Exposure to contaminants such as the antibacterial agent Triclosan (Hay et al 2001;Drury et al 2013) and the herbicide Diuron (Sumpono et al 2003;Seghers et al 2003) has been observed to place microbial communities under a selective pressure that favors microorganisms that can use these contaminants as an additional carbon source.…”

Application of the D-A-(C) index as a simple tool for microbial-ecological characterization and assessment of groundwater ecosystems—a case study of the Mur River Valley, Austria

“…Furthermore, we explored the usefulness of DOM quality indices derived from fluorescence spectroscopy as promising additional parameters to be included in the D-A-(C) index. Fluorescence spectroscopy of DOM has previously been used mainly to examine shifts in DOM composition in surface water systems with season, changing environmental conditions, or in response to anthropogenic impacts, (Benk et al 2019;Coble et al 2014;Harjung et al 2020). Moreover, it has been used to study risks of fecal contamination in groundwater and drinking water systems (Frank et al 2018;Nowicki et al 2019;Sorensen et al , 2020.…”

Synthetic and biological surfactant effects on freshwater biofilm community composition and metabolic activity

“…There is a growing body of evidence that anthropogenic trace contaminants, and contaminants of emerging concern (CECs), such as pharmaceuticals, herbicides, and antimicrobial agents can have major impacts upon the composition and functioning of aquatic microbial communities (Rosi-Marshall et al 2013;Argudo et al 2020;Harjung et al 2020;McClean and Hunter 2020;Ke et al 2020;Kusi et al 2020). Exposure to contaminants such as the antibacterial agent Triclosan (Hay et al 2001;Drury et al 2013) and the herbicide Diuron (Sumpono et al 2003;Seghers et al 2003) have been observed to place microbial communities under a selective pressure that favors microorganisms that can use these contaminants as an additional carbon source.…”