Oral Presentation Society of Environmental Toxicology and Chemistry Australasia 2021

Using non-destructive sampling techniques to detect impacts of metals in the freshwater snail Physa acuta (#118)

SARA LONG 1 , Michela Di Giannantonio 1 2 , Jackie Myers 1 , Rhys Coleman 3 , Vincent Pettigrove 1
  1. A3P, RMIT University, Melbourne, Victoria, Australia
  2. Institute for the study of anthropogenic impacts and sustainability in the marine environment, National Research Council, Genova, Italy
  3. Applied Research, Melbourne Water Corporation, Melbourne, Victoria, Australia

Measuring biological responses in resident biota is a common approach for assessing environmental impacts. Ideally, these responses will be stressor-specific and sensitive, so they can be used diagnostically as early warning indicators of environmental stress. Traditionally, measuring biological responses in individuals involves destructive sampling of the organism which potentially limits the range of organisms to laboratory cultures or those collected from the field. Environmental metabolomics uses analytical techniques to detect and quantify small molecular weight metabolites (such as sugars, amino acids and products of biochemical pathways) produced in biota in response to their environment. Previous studies have shown the capability of metabolomic approaches to detect changes in metabolite abundance in organisms exposed to low concentrations of pollutants. The aim of the present study was to design a method for non-destructive collection, extraction and detection of metabolites from mucus from the freshwater snail Physa acuta. The second aim was to determine whether this approach can be used to detect responses in snails following exposure to heavy metals. Optimisation experiments were carried out to develop and validate the sampling, extraction and detection of metabolites in unexposed P. acuta mucus sampled from our in-house culture. Following this, snails were exposed to low doses of copper and zinc for 24 hours and thereafter mucus was collected on filter paper. Polar metabolites were detected and quantified using gas chromatography mass spectrometry (GC-MS) and identified using an in-house metabolite standard library. Results will be discussed in terms of suitability of using non-destructive sampling techniques in ecotoxicology experiments and for identifying candidate biomarkers of metal exposure. Further, results will be compared with previous studies to assess whether there are common metabolites that respond to metals irrespective of taxonomic group.