APG-containing product reduces dissolved oxygen in freshwater pond mesocosms: Implications for benthic macroinvertebrate abundance

Widely-used household chemicals have the potential to enter aquatic systems, where organisms can be affected by direct toxicity through exposure or indirect toxicity through changes in water quality. Products marketed as being "naturally derived" often contain the surfactant alkyl polyglucoside (APG), which has been shown to have low toxicity in single species laboratory testing. However, little is known about how APG-containing products can affect communities of organisms in the field. A study was conducted in southeastern Georgia, USA, to determine whether the presence of a product containing APG changed water quality and the abundance and community diversity of benthic macroinvertebrates in a blackwater pond. A household cleaner containing APG was added to in situ mesocosms in concentrations of 0.1 % and 1 % of total mesocosm volume. Water quality parameters were measured every 4 days for two weeks, and the benthic macroinvertebrate community was sampled at the end of the experiment. We found that mesocosms with APG-containing product concentrations of 0.1 % and 1 % of total mesocosm volume had 75 ± 7 % and 80 ± 15 % decreases in water column DO, respectively. In addition, both APG treatments trended toward lower total abundances of macroinvertebrates, in particular Chironomidae and Oligochaeta, than the control treatment. Results suggest the presence of APG-containing chemicals in lentic systems increases biological oxygen demand and could influence community structure, which has important implications for community function of contaminated water bodies.