Using laboratory-cultured nonbiting midge larvae (Chironomus tepperi) to identify early metabolic changes following exposure to zinc

Measuring biological responses in resident biota is a commonly used approach for monitoring disturbed habitats. Ideally, these responses will be stressor-specific, so they can be used diagnostically, and sensitive, so they are early warning indicators of environmental stress. Previous studies have shown the capability of metabolomics approaches to detect changes in metabolite abundance in organisms exposed to low concentrations of pollutants. This study investigated the effects of 24-h exposure to zinc on the Australian aquatic invertebrate, Chironomis tepperi. A multiplatform metabolomics approach (gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS)) was used to identify potential biomarkers of zinc exposure. Exposure to zinc resulted in changes in the abundance of metabolites involved in energy metabolism and intermediates of the transsulfuration pathway. Further research is required to ascertain if these changes in metabolite abundance are specific to zinc. This study demonstrates the potential of using metabolomics alongside other measures of environmental conditions to assess ecosystem health.