APG-Containing Product Reduces Water Quality and Food Availability to Primary Consumers in Freshwater Microcosms

Abstract

In response to loss and degradation of freshwater resources, the production volume and use of eco-friendly cleaners is rising. The active ingredients in these products, alkyl polyglucosides (APGs), are naturally-derived, low-toxicity surfactants that biodegrade rapidly. While direct contact may be non-toxic to most aquatic organisms, the potential for oxygen depletion during APG biodegradation and subsequent effects on aquatic communities have not been examined. We tested the effects of environmentally relevant concentrations of APG on water quality and phytoplankton and zooplankton abundance in freshwater microcosms. A decrease in dissolved oxygen (DO) of up to 2 mg L^-1 and an increase in conductivity occurred in the highest APG concentration tested (0.1%). Phytoplankton (Chlorella spp.) concentrations were also reduced in the 0.1% APG treatment at the end of the experiment. Although zooplankton abundance (Daphnia magna and Cypridopsis spp.) was not significantly affected by the presence of APG, there was a trend of fewer and smaller D. magna produced. The potential for APG degradation to reduce DO and microalgal concentrations demonstrates the need for additional research into the effects of APG on food web interactions in aquatic communities.