NMR-based metabolomics of dragonfly nymphs exposed to multiple stressors: An approach for field assessments to diagnose effects

The Athabasca River flows through northeastern Alberta, Canada, and this region contains one of the largest oil deposits in the world. The river receives heavy metals and polycyclic aromatic hydrocarbons from natural erosion of oil-containing sands, i.e., bitumen. In addition, spatial cooccurrence with oil sands (OS) development (surface mining) and discharge of treated municipal sewage effluent (MSE) into the Athabasca River further complicates ecological bioassessments. The objective of this in situ experiment was to use NMR-based metabolomics of caged, transplanted dragonfly (Ophiogomphus colubrinus) nymphs to investigate the multiple stressor effects of MSE and OS activities on the health of the Athabasca River. After 1-week exposure, we found a high survival of dragonfly nymphs among all four sites. The nymph metabolomes did not differ among exposure sites. We identify specific research steps to assess if longer exposure periods are necessary to ascertain if multiple sublethal stressors in this large river affect nymph metabolomes.