Dr Damien Maher
COAL SEAM GAS AND THE ENVIRONMENT
A massive growth of the coal seam gas industry has occurred in NSW and QLD in the last decade. Even faster growth rates are predicted for the next decade. However, our basic understanding about the influence of CSG mining on the environment remains very limited.
In addition, fugitive greenhouse gas emissions from CSG fields have not been investigated in Australia yet. We recently made a submission to the government reporting the first, but still very preliminary, observations of greenhouse gases in the atmosphere of an Australian CSG field. Our submission has generated intense debate in the media:
Our group has the expertise and cutting edge technology to assess greenhouse gases in water and the atmosphere of CSG fields. We recently obtained a large infrastructure grant from the Australian Research Council that puts us in an excellent position to fill some of the major emerging knowledge gaps. Our group is interested in addressing the following questions:
Will creek hydrology and chemistry be impacted by coal seam gas exploration? Many of our creeks are thought to be fed by groundwater seepage. We are investigating whether fracking and groundwater extraction by CSG mining will interfere with groundwater surface water exchange using natural geochemical tracers such as radon.
What is the baseline groundwater chemistry in coal seam gas exploration areas? It is unresolved whether aquifer connectivity will be disturbed by CSG exploration. We propose to determine the baseline chemical composition of groundwaters potentially (or currently) impacted by CSG exploration and to prepare regional maps of groundwater chemistry. We believe methane concentrations and isotopes are a priority chemical analysis in this context. SCU has all the analytical facilities and expertise to perform high precision measurements of all key chemical parameters.
What is the net input of greenhouse gases into the atmosphere associated with CSG mining? Fugitive emissions are unintended gas losses that may occur anytime from the early gas exploration stages all the way to the end users. Current estimates (from overseas) for methane fugitive emissions range from about 0.1 to 8% of the total gas produced. We currently assume the Australian CSG industry fugitive emissions to be at the low end of the spectrum. While this is clearly possible, it has not been verified by any independent studies in Australia.
SCU has cutting edge technology to detect leakages of gases from wells, pipelines, compression stations or ponds. We can map gases such as methane and carbon dioxide (concentrations and isotopes) with high precision and great spatial resolution. Our portable, high precision instrumentation can be deployed in a car or small aircraft to obtain real time results that can be used to determine the sources of methane and carbon dioxide to the atmosphere (e.g. natural wetland sources as opposed to leakage of gases from CSG industries). We plan to link our field observations to cutting edge physical models to quantify full cycle fugitive emissions from CSG activities.
THE "MISSING MANGROVE CARBON"
Mangroves are ecologically important, productive and extremely carbon rich habitats, that dominate the coastal zone in subtropical and tropical latitudes. In spite of the obvious importance of these habitats, there is still a paucity of data on many of the carbon cycling processes within these systems. One such information gap is evident by the unbalanced global mangrove carbon budget, with more than half of the carbon fixed through primary production unaccounted for. This is the stimulus for one component of the research that I have been carrying out, with initial results indicating that this "missing" carbon maybe dissolved inorganic carbon, derived from subsurface respiration, which is subsequently exported through the groundwater pathway (Maher et al, submitted Limnology and Oceanography).
AN INTEGRATED CARBON MONITORING SYSTEM
I am also working on an integrated dissolved carbon monitoring system that will autonomously monitor the various dissolved carbon pools including; dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and volatile organic carbon (VOC). This work stems from the need to better understand the pathways and cycling processes of carbon in the coastal zone, and follows on from the success we have had with a coupled radon/pCO2 system (Santos, Maher and Eyre, Accepted, Environmental Science and Technology) for investigating the role of groundwater in driving pCO2 dynamics in rivers and estuaries.
THE EXPORT OF TERRESTRIAL CARBON VIA GROUNDWATER
Rivers and estuaries are often supersaturated in CO2 and traditionally this has been linked to export of organic carbon from terrestrial environments, which is respired within the aquatic environment. However, groundwater is often enriched in dissolved carbon and 1 – 2 orders of magnitude higher in pCO2 than surface waters, therefore groundwater inputs can have a significant influence over surface water pCO2 and dissolved carbon concentrations. A portion of this groundwater carbon is derived from terrestrial subsurface respiration, which is not accounted for in terrestrial carbon budgets which are normally based on measurements of CO2 above the soil surface (e.g. eddy covariance and chamber incubations), and therefore tend to neglect subsurface pathways. I am currently working on a number of projects looking at the magnitude of the groundwater carbon input to aquatic systems, and how this pathway should be integrated into the global carbon cycle.
Traditional methods (e.g. benthic cores and chambers) have inherent artefacts that may lead to inaccuracies in benthic flux calculations. Eddy correlation is a relatively new method for measuring benthic fluxes, which eliminates many of the artefacts associated with traditional techniques. We have two eddy correlation systems, which we are currently using to investigate benthic oxygen fluxes in a range of complex coastal habitats.
Category 1 Grants
- $5400 AINSE Grant no. AINGRA07045 - "Sedimentation rates in three NSW estuaries."
-$30 000 ($15 000 NOROC, $15 000 SCU)" Preliminary assessment of groundwater and creek water chemistry in CSG exploration areas of the Northern Rivers Region"
- $24 000 "Do residential canal estate developments increase greenhouse gas emissions from Australian estuaries". CI 2 of 2 Funding agency: Australian Academy of Science WH Gladstone's Population and Environment Fund. 2 Years
- $18,080. "Is groundwater discharge a major source of nutrients and eutrophication to Brisbane Water?" - CI 1of 3. Gosford City Council. 2012-2014.
- $50000 - "Benthic habitat mapping and primary productivity measurements in the Hastings River and Camden haven estuaries. " Port Macquarie Hastings Council
In Press/Accepted/Revision Requested
Eyre, B. D., Santos, I. R. and Maher, D. T. 2013 Seasonal, daily and diel fluxes of N2 in permeable carbonate sediments. Biogeosciences JIF = 3.859 (ERA Rank A)
Atkins, M., Santos, I. R., Ruiz-Halpern, S., Maher, D. T. 2013. Carbon dioxide dynamics driven by groundwater discharge in a coastal floodplain creek. Journal of Hydrology JIF = 3.271 (ERA Rank A*)
Tait, D. R., Santos, I. R., Maher, D. T., Cyronak, T. J., and Davis, R. J. 2013. Enrichment of radon and carbon dioxide in the open atmosphere of an Australian coal seam gas field. Environmental Science & Technology JIF = 4.363 (ERA Rank A*)
Gleeson, J., Santos, I. R., Maher, D. T. and Golsby-Smith, L. 2013 Groundwater-surface water exchange in a mangrove tidal creek: Evidence from natural geochemical tracers and implications for nutrient budgets Marine Chemistry JIF 3.551 (ERA Rank A)
Maher, D.; Santos, I.R.; Gleeson, J.; Golsby-Smith, L.; Eyre, B.D. 2013. Groundwater-derived dissolved inorganic and organic carbon exports from a mangrove tidal creek: The missing mangrove carbon sink? Limnology and Oceanography, 58(2): 475-488. ERA: A; JIF: 3.59
Santos, I. R. Maher, D. and Eyre, B. D. 2012. Coupling automated radon and carbon dioxide measurements in coastal waters. Environmental Science and Technology 46, 7685-7691. JIF = 4.363. (ERA Rank *A).
Maher, D., and B. D. Eyre. 2012. Carbon budgets for three autotrophic Australian estuaries: Implications for global estimates of the coastal air-water CO2 flux. . Global Biogeochemical Cycles 26: GB1032. JIF=4.29 (ERA Rank A*)
Maher, D. and Eyre, B. D. Benthic metabolism in southeast Australian estuaries: habitat importance, driving forces, and application of artificial neural network models. Marine Ecology Progress Series 439, 97-115. doi:10.3354/meps09336. JIF = 2.63; (ERA Rank A).
Eyre, B. D., Maher, D., Oakes, J. M., Erler, D. V. and Glasby, T. Differences in benthic metabolism, nutrient fluxes and denitrification in Caulerpa taxifolia communities compared to uninvaded sediment and seagrass (Zostera capricorni). Limnology and Oceanography 56, 1737-1750. JIF = 3.66; (ERA Rank A).
Oakes, J. M., Bautista, M. D., Jones, W. B., Maher, D., and Eyre, B. D. Carbon self-utilisation may assist Caulerpa taxifolia invasion. Limnology and Oceanography 56, 1824-1831. JIF = 3.66; (ERA Rank A).
Santos, I. R., Glud, R. N., Maher, D. and Eyre, B. D. 2011. Diel coral reef acidification driven by pore water advection in permeable carbonate sands, Heron Island, Great Barrier Reef. Geophysical Research Letters 38, L03604, doi:10.1029/2010GL046053. JIF= 2.959; (ERA Rank *A)
Maher, D. and Eyre, B. D. 2011. Insights into estuarine benthic dissolved organic carbon (DOC) dynamics using 13C- DOC values, phospholipid fatty acids and dissolved organic nutrient fluxes. Geochimica et Cosmochimica Acta 75, 1889-1902. JIF= 4.33; (ERA Rank *A)
Eyre, B. D. and Maher, D. 2011. Mapping ecosystem processes and function across shallow seascapes. Continental Shelf Research (in press) doi:10.1016/j.csr.2010.01.013 JIF=2.14. (ERA Rank A).
Eyre, B. D., A. J. P. Ferguson, A. Webb, D. Maher and J. M. Oakes. 2011. Denitrification, N-fixation and nitrogen and phosphorus fluxes in different benthic habitats and their contribution to the nitrogen and phosphorus budgets of a shallow oligotrophic sub-tropical coastal system (southern Moreton Bay, Australia). Biogeochemistry 102, 111-133. doi: 10.1007/s10533-010-9425-6. JIF=2.96. (ERA Rank A).
Eyre, B. D., A. J. P. Ferguson, A. Webb, D. Maher and J. M. Oakes. 2011. Metabolism of different benthic habitats and their contribution to the carbon budget of a shallow oligotrophic sub-tropical coastal system (southern Moreton Bay, Australia). Biogeochemistry 102, 87-110. doi: 10.1007/s10533-010-9424-7. JIF=2.96. (ERA Rank A).
Maher, D. T., and B. D. Eyre. 2010. Benthic fluxes of dissolved organic carbon in three temperate Australian estuaries: Implications for global estimates of benthic DOC fluxes, Journal of Geophysical Research 115, G04039, doi:10.1029/2010JG001433. JIF=3.082. (*A).
Eyre, B. D. and Maher, D. 2010. Structure and function of warm temperate east Australian coastal lagoons: implications for natural and anthropogenic change. In: Kennish, M. J. and Paerl, H. W. (eds.). Coastal Lagoons: Critical habitats of environmental change. CRC Press. pp. 457-481.
Veuger, B., Eyre, B.D., Maher, D., and Middelburg, J. J. 2007. Nitrogen incorporation and retention by bacteria, algae, and fauna in a sub-tropical, intertidal sediment: An in-situ 15N-labeling approach. Limnology and Oceanography 52, 1930-1942.
Maher, D. T. and Eyre, B. D. 2012. Sediment oxygen demand of the Pine Rivers Estuary. Centre for Coastal Biogeochemistry Report No. 2012-01 for Healthy Waterways. 14p.
Eyre, B. D. and Maher, D. 2011. Sediment biogeochemistry in the Caboolture River estuary. Centre for Coastal Biogeochemistry Report No. 2011-01 for Moreton Bay Regional Council. 22 p.
Eyre, B. D., Reichelt-Brushett, A., Sharp, D. and Maher, D. 2008. Ecology and biogeochemistry. Macleay Estuary Processes Study. Centre for Coastal Biogeochemistry Report No. 2008-02 for Kempsey Shire Council
Maher, D. Eyre, B. D. and Squire, P. 2007. Benthic habitat mapping, primary productivity measurements and macrofauna surveys in the Camden Haven and Hastings River Estuaries. Report to Port Macquarie Hastings Council. Centre for Coastal Biogeochemistry Report No. 2007-05. 60p.
Ferguson, A. J. P., Eyre, B. D., Webb, A., Reichelt-Brushett, A. and Maher, D. 2004. Sediment Biogeochemistry - Pimpama River Estuary Ecological Study. Centre for Coastal Biogeochemistry Report No. 2004-01. 55 p
Alexander, I., Maher, D. and Eyre, B. D. 2004. Experimental Design and Data Report -Moreton Bay Dredging and Spoil Site Experiments. Centre for Coastal Biogeochemistry Report No. 2004-06. 6 p.
Updated: 30 April 2013