Using field-collected estuarine worms to identify early metabolic changes following exposure to zinc

The effects on estuarine biota of exposure to contaminants are not well understood. Furthermore, the immediate impact of chemical exposure on these organisms is poorly described. This study used metabolomics approaches to look at metabolite changes following zinc exposure. The estuarine worm Simplisetia aequisetis was collected from an intertidal mud flat, returned to the laboratory, and exposed to a sublethal concentration of zinc (approximately 10% LC50) for 2 weeks. Worms were sampled at six time points over the 2-week period. A multiplatform metabolomics approach was used to look at the changes in polar and amine-containing metabolites in the worms. Results showed that changes in metabolite abundance occurred from 24 h of exposure but that changes in abundance of some metabolites were observed at later time points. This demonstrates the usefulness of measuring metabolite abundance over time rather than at just one time point. Furthermore, as changes in metabolite abundance were observed before changes in physiological endpoints such as energy reserves and growth, metabolomics approaches show promise as part of the biomonitoring toolkit to assess ecosystem health.