New tools to detect ecological effects of contaminants in estuaries

ARC Linkage project

Partners: Melbourne Water, CSIRO and Metabolomics Australia

Sara Long and Allyson O’Brien

Background

• Contaminants (usually in mixtures) can have major impacts on estuaries

• Current assessment methods are: – Do not accurately measure ecological responses – Identify the most severe threat – Expensive

• New molecular techniques may help with this

Aims

• Develop molecular tools (metabolomics and metabarcoding) for monitoring and assessing pollution stress in estuarine ecosystems

• Validation using field experiments

Estuaries • 81% of Australia’s population

live within 50 km of estuaries • Provide valuable ecosystem

services • Impacted by urban

development (metals & pesticides) and agricultural run off (fungicides, insecticides & herbicides)

Environmental Metabolomics • Small molecular weight molecules • Simultaneously measure 50-1000

metabolites • Holistic • A range of methodologies

• Sensitive • Effects observed at lower concentrations

than other endpoints

• Diagnostic for specific chemicals • Cost effective

Collaboration with Dr Dedreia Tull, Dr Con Kouremonos, David De Souza and Prof Malcolm McConville at Bio21 Institute

Research Questions • To what extent might

different taxa respond in the same way to chemicals?

• Are there any chemical-specific metabolites? Little River Estuary. Source: Georgia Sinclair

Approach

• Snail Nassarius burchardi and worm Simplisetia aequisetis

• Common and abundant in estuarine intertidal mudflats

• Easy to collect and maintain in the laboratory • Exposure to copper, zinc and boscalid • Metabolomics analysis

Comparing metabolite responses between species and metals

Trends in metabolite changes - Zinc

Decreased abundance – Tyrosine – Epinephrine – Normetanephrine – Phenylalanine – Tryptophan – Leucine

Photo : Georgia Sinclair

Conclusions • Two species responded

differently to the same chemicals – Worms more sensitive than snails – Family/traits

• Handful of metabolites responded to specifically to zinc

• Metabolomics promising tool to detect effects of metal exposure in estuarine organisms

Metabarcoding

• DNA metabarcoding OR eDNA • Less commonly used in ecological research • Estuarine sediments • Monitoring and diagnostic tool Collaboration with

Dr. Anthony Chariton and Sarah Stephenson

CSIRO Oceans and Atmosphere

Chariton et al. (2010) Frontiers in Ecology and Environment

Field survey

Mesocosms

Field experiments using mesocosms (experimental units)

O’Brien and Keough 2013

Field experiments Individual and community response measured using metabolomics and

metabarcoding 1. Two pesticides

– Diuron (herbicide) – Boscalid (fungicide)

2. Metal and pesticide – Copper in sediment – Pesticide applied by spraying

Outcomes

• Adaptable experimental approach using mesocosms

• Biologically relevant endpoints (individuals & communities)

• Cost-effective compared to traditional counting and identification approach

• Ecological relevant indicators of change

Future directions & opportunities

• Improving details of each approach. • “Community metabolomics &

metabarcoding”. • Test in estuaries along a pollution gradient. • Working with our industry partner, Melbourne

Water, to make these tools useable.

Acknowledgements CAPIM Georgia Sinclair Gigi Woods Rhianna Boyle Kathryn Hassell Ruther Lee Claudette Kellar Liz Morris Katy Jeppe Vin Pettigrove CAPIM team

Funding

• Australian Research Council

ARC LP project LP140100565 • Melbourne Water: Dr

Rhys Coleman & Dr Melita Stevens

• CSIRO

Metabolomics Australia (Bio21) Komal Kanoija Saravanan Dayalan Sean O’Callaghan