contamination in estuaries: detecting ecological impacts allyson o’brien, gigi woods, liz morris...
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Contamination in estuaries: detecting ecological impacts
Allyson O’Brien, Gigi Woods, Liz Morris & Mick Keough
School of BioSciencesUniversity of Melbourne
Centre for Aquatic PollutionIdentification and Management
Cause-effect relationships• Fundamental to environmental guidelines• Reliable risk assessments• We know they are variable • We know less about:
• Levels of biological organisation• Ecological processes
253
1442
n = 13Linked individual responses to population or community changes
Marine experiments
O’Brien & Keough 2014 (Environmental Pollution)
Estuarine toxicity tests
Gammaropsis sp.
Simplesetia aequistis
Individual endpoints• Survival• Behaviour – Gigi Woods • Metabolomics – Sara Long (CAPIM,
Bio21 Institute)Population-level endpoints
• Population growth• Size-class structure
Community-level endpoints• Microbial functional diversity – Liz
Morris
Laboratory experiment – April 2015
• Cu-dosed estuarine sediment • O, 100, 200, 300 mg/kg • Amphipods and microbial
communities• 2 week experiment
Endpoints• Individual
– Survival ✔– Behaviour ✔– Metabolomics
• Population-level endpoints– Population growth– Size-class structure
• Community-level – Microbial functional diversity ✔
Results – survival & behaviourNumber of
amphipods/beaker (range)
Control 0 – 3
100 mg/kg 1 – 5
200 mg/kg 0 – 3
300 mg/kg 1 – 3
These were all from the largest size class
Different rates of burrowing
Microbial functional diversity• Biolog EcoplatesTM
• Measures metabolism of 31 carbon sources per assay
• Distinguishes spatial and temporal changes in microbial communities
• Used in Melbourne Water Western Treatment Plant monitoring program
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Tota
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Amino acids
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7Carbohydrates
Copper concentration (mg/kg)
Where to from here?
• Did the spiking work?• Improve survival in laboratory populations• Amphipod behaviour could be a sensitive indicator.
Also using polychaetes.• Microbial functional diversity (ecoplates) worth
pursuing• Metabolomics with Sara Long & Metabolomics
Australia (Bio21 Institute)
Field mesocosms• Aim: To develop an experimental approach that
could be used to detect causality
• Mesocosm = experimental unit
Easily transported deployed sampled
Field mesocosms
• Translocation experiments using whole sediments• Defaunated by freezing• Deployed in intertidal sediments• Multiple estuary experiments
✚
✚Watsons Creek
Lake Borrie
O’Brien & Keough 2013 (Environmental Pollution)
Where to from here? – field mesocosms
• Field dosing experiments• Incorporate DNA metabarcoding – ARC
Linkage project & collaboration with CSIRO
• Overcome study bias– Lab experiments = individual responses– Field experiments = community responses
• How do we link responses at the individual-level to populations and communities?
Where to from here? – more broadly
• Co-authors and collaborators:– Liz Morris– Gigi Woods– Sara Long– Anthony Chariton– Mick Keough
Acknowledgements