My research topics include carbon and nitrogen biogeochemistry in coastal ecosystems with a special interest in understanding how anthropogenic disturbances affect ecosystems functioning. Most of my work involves the use of stable isotopes at both natural abundance and artificially enriched levels for investigating the sources and transformation pathways of carbon and nitrogen in ecosystems, as well as for understanding trophic relationships and food web structure.After completing a PhD examining the biogeochemical and ecological consequences of sewage discharge on mangrove environments, I recently joined the Centre for Coastal Biogeochemistry where I'm currently involved in an ARC linkage project studying nitrogen cycling in the Caboolture River catchment and estuary. My contribution to this project focuses on two main objectives:
To develop a multi-isotope tracer approach in order to trace nitrogen sources along the freshwater-marine continuum.
Nitrogen stable isotopes (δ15N) have been efficiently used for many decades to identify sewage pollution in groundwater, catchment and estuaries but cannot solely be used to distinguish N derived from synthetic fertilisers and atmospheric deposits A combination of stable isotopes (δ15N-NO3, δ18O-NO3, δ17O-NO3, δ11B) to distinguish the 4 major N sources: (1) atmospheric, (2) fertilisers, (3) soil and (4) sewage..This work involves method development work and validation on the Isotope Ratios Mass Spectrometer and will be applied in the Caboolture River catchment and estuary.
To assess the contribution of denitrification to nitrogen removal in the Caboolture catchment.
The large amounts of nitrogen (N) inputs delivered from catchments to coastal waters represent a major threat to coastal ecosystems worldwide. Luckily, almost 80% of this catchment nitrogen doesn't make it to the coast, part of it being permanently removed via denitrification. Denitrification therefore regulates the downstream transport of N from freshwater to marine environments. While it has been extensively studied in terrestrial, freshwater, and marine systems, only a limited number of studies integrate denitrification measurements along the entire freshwater marine continuum. Effective management of nitrogen over-enrichment of coastal systems thus requires a thorough understanding of denitrification across the entire catchment. This work will thus aim at assessing where within the Caboolture River catchment and estuary denitrification occurs and will help quantifying the contribution of denitrification to N-removal in the system.
MAJOR RESEARCH GRANTS
-$240,000 (LE130100153) "A liquid chromatography/ gas bench: isotope ratio mass spectrometer for new and novel carbon and nitrogen research in coastal systems" 2013. Project Leader.
Updated: 08 November 2012