Associate Professor Isaac Santos

Dr. Isaac Santos interview on ABC Radio Australia on 17 November 11

RESEARCH INTERESTS

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:

'Gas Leak', Four Corners, April 1 2013

'Research questions green credentials of CSG', ABC 730, November 14 2012

'Methane leaking from coal seam gas field, testing shows', Sydney Morning Herald, November 14 2012

'Newman concerned by CSG methane report', The Australian, November 15 2012

'Elevated atmospheric methane found on QLD gasfield', ABC World Today, November 15 2012

ABC North Coast Radio Interview

Radio National Interview-"The missing Emissions"

Radio National Breakfast Interview

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.

PERMEABLE SEDIMENTS

I am currently investigating nitrogen cycling in permeable sediments using a combination field and laboratory experiments. We suspect that high primary production in nutrient-starved coral reef environments is supported by rapid organic matter recycling in permeable sediments. Most previous studies on benthic nitrogen cycling have focused on muddy sediments. The key difference between muddy and sandy sediments is their permeability, which allows water to flow through pore spaces between the sand grains. Flushing of porewaters results in a greater transport of oxygen and organic matter into the sediment, leading to mineralisation rates as high, or higher, than muddy sediments.

SUBMARINE GROUNDWATER DISCHARGE

I use radionuclides as tracers of submarine groundwater discharge (SGD). SGD is an important, but overlooked and invisible global source of trace elements and nutrients into the coastal ocean. Radon and radium isotopes are excellent SGD tracers as they are highly enriched in groundwaters relative to surface waters and they are conservative in seawater. I am currently using radon to trace groundwater discharge into Australian estuaries surrounded by coastal acid sulphate soils.

SUBTERRANEAN ESTUARIES BIOGEOCHEMISTRY

I am also interested in carbon and nutrient cycling in subterranean estuaries. Nutrient cycling in subterranean estuaries can be fuelled by oxygen and organic matter inputs driven into the aquifer by tidal pumping. Nutrient and dissolved organic carbon production dominates in subterranean estuaries, while nutrient removal dominates in surface estuaries. After accounting for biogeochemical additions into subterranean estuaries, SGD-derived nutrient fluxes can be dramatically enhanced.

MAJOR RESEARCH GRANTS

ARC Discovery

-$260,000 (DP120101645) Are subterranean estuaries a source or sink of greenhouse gases?, Lead Chief Investigator, 2012-2014

- $310,000 (DP110103638 "Unravelling the synergistic effect of ocean acidification and pore water advection on carbonate sediment dissolution: a global sink for CO2?" 2011-2013. CI 2 of 3.

ARC Linkage

-$546,670 (LP110200975) Unravelling the cycling of nitrogen along a subtropical freshwater-marine continuum using a multi-isotope, multi-tracer and modelling approach 2011 to 2014. CI 2 of 4.

- $607,000 (LP100200732) "Resolving nitrogen and phosphorus transformations along subterranean estuary-sediment/water interface continuums in carbonate sands" 2010 to 2013. CI 2 of 3.

ARC LIEF

-$240,000 (LE130100153) "A liquid chromatography/ gas bench: isotope ratio mass spectrometer for new and novel carbon and nitrogen research in coastal systems" 2013. CI 2 of 5

-$250,000 (LIEF LE120100156) A high precision, automated system for studying greenhouse gas cycling in coastal environments, Lead Chief Investigator, 2012

- $170,000 (LE100100013) "Eddy Correlation Lander Array" 2010. CI 4 of 12.

Other Category 1 Grants

- $84,410 "Are groundwater inputs driving de-oxygenation, acidification and eutrophication." Herman Slade Foundation. 2009 to 2012. Project Leader.

Other

- $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? Australian Academy of Sciences W H Gladstone Fund. Lead CI.

- $18,080. "Is groundwater discharge a major source of nutrients and eutrophication to Brisbane Water?" - Gosford City Council. 2012-2014. CI 2 of 3.

- $12,000(NZ) "Unravelling submarine groundwater discharge in New Zealand estuaries" ISAT Fund - New Zealand Academy of Sciences" 2010.

PUBLICATIONS

2013

Tait, D.R.; Santos, I.R.; Maher, D.T.; Cyronak, T.; Davis, R. 2013. Enrichment of radon and carbon dioxide in the open atmosphere of an Australian coal seam gas field. Environmental Science and Technology, in press. ERA: A*; JIF: 5.23

Atkins, M.L.; 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, in press. ERA: A*; JIF: 2.66

Tait, D.R.; Santos, I.R.; Erler, D.V.; Befus, K.M.; Cardenas, M.B.; Eyre, B.D. 2013. Estimating submarine groundwater discharge in a South Pacific coral reef lagoon using different radioisotope and geophysical approaches. Marine Chemistry, in press. ERA: A; JIF: 3.01

Cyronak, T.; Santos, I.R.; Erler, D.; Eyre, B.D. 2013. Groundwater and porewater as a major source of alkalinity to a fringing coral reef lagoon (Muri Lagoon, Cook Islands). Biogeosciences. in press. ERA: A; JIF: 3.86

Eyre, B.D.; Santos, I.R.; Maher, D. Seasonal, daily and diel N2 effluxes in permeable carbonate sediments. Biogeosciences, in press. ERA: A; JIF: 3.86

Gleeson, J.; Santos, I.R.; Maher, D. T.; 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, in press. ERA: A; JIF: 3.01.

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., de Weys, J., Tait, D.; Eyre, B.D. 2013. The contribution of groundwater discharge to nutrient exports from a coastal catchment: Post flood seepage increases estuarine N:P ratios. Estuaries and Coasts, 36: 56-73. ERA: B; JIF: 2.11

Cyronak, T.; Santos, I.R.; MacMahon, A.; Eyre, B.D. 2013. Carbon cycling hysteresis in permeable carbonate sands over a diurnal cycle: Implications for ocean acidification. Limnology and Oceanography, 58(1): 131-143. ERA: A; JIF: 3.59

Peterson, R.N., Burnett, W.C.; Opsahl, S.P.; Santos, I.R.; Misra, S.; Froelich, P.N. 2013. Tracking suspended particle transport via radium isotopes (226Ra and 228Ra) through the Apalachicola-Chattahoochee-Flint River system. Journal of Environmental Radioactivity, 116: 65-75. ERA: C; JIF: 1.34

2012

Santos, I.R., Eyre, B.D. and Glud, R.N., 2012. Influence of porewater advection on denitrification in carbonate sands: Evidence from repacked sediment column experiments. Geochimica et Cosmochimica Acta, 96: 247-258.. ERA: A*; JIF: 4.38

Santos, I.R.; Maher, D.; Eyre, B.D. 2012. Coupling automated radon and carbon dioxide measurements in coastal waters. Environmental Science and Technology, 46: 7685-7691. ERA: A*; JIF: 5.41

Santos, I.R., Cook, P.L.M., Rogers, L., de Weys, J. and Eyre, B.D., 2012. The 'salt wedge pump': Convection-driven porewater exchange as a source of dissolved organic and inorganic carbon and nitrogen to an estuary. Limnology and Oceanography, 57: 1415-1426. ERA: A; JIF: 4.38

Sanders, C.J., Santos, I.R., Barcellos, R. and Silva Filho, E.V., 2012. Elevated concentrations of dissolved Ba, Fe and Mn in a mangrove subterranean estuary: Consequence of sea level rise? Continental Shelf Research, 43: 86-94. ERA: A; JIF: 1.61

Santos, I.R., Eyre, B.D., Huettel, M., 2012. The driving forces of porewater and groundwater flow in permeable coastal sediments: A review. Estuarine Coastal and Shelf Science, 98: 1-15. ERA: A; JIF: 1.97

Andrade, C.F.F.; Niencheski, L.F.H.; Santos, I.R.; Attisano, K.K.; Milani, I.C.; Milani, M.R. 2012. Nutrients fluxes from groundwater discharge into Mangueira Lagoon (Rio Grande do Sul, Brasil), Quimica Nova, 35(1): 5-11. ERA: C; JIF: 1.01

2011

Santos, I.R., de Weys, J., Eyre, B.D., 2011. Groundwater or floodwater? Assessing the pathways of metal exports from a coastal acid sulfate soil catchment. Environmental Science & Technology 45, 9641-9648. JIF = 4.363. (ERA Rank *A).

Santos, I.R.; Burnett, W.C.; Misra, S.; Suryaputra, I G.N.A.; Chanton, J.; Dittmar, T., Peterson, R.N.; Swarzenski, P.W. 2011. Uranium and barium cycling in a salt wedge subterranean estuary: The influence of tidal pumping. Chemical Geology, 287: 114-223. (ERA: A*)

Schmidt, A.; Santos, I.R.; Burnett, W.C.; Niencheski, F.; Knöller. K. 2011. Groundwater sources in a permeable coastal barrier: Evidence from stable isotopes. Journal of Hydrology, 406: 66-72. (ERA: A*)

Ivar do Sul, J.A.; Santos, I.R.; Friedrich, A.C.; Matthiensen, A.; Fillmann, G. 2011. Plastic Pollution at a sea turtle conservation area in NE Brazil: Contrasting developed and undeveloped beaches. Estuaries and Coasts, 34: 814-823. DOI: 10.1007/s12237-011-9392-8. (ERA: B)

de Weys, J., Santos, I. R. and Eyre, B. D. Linking groundwater discharge to severe estuarine acidification during a flood in a modified wetland. Environmental Science and Technology 45, 3310-3316. JIF = 4.363. (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)

Santos, I. R. and Eyre, B. D. 2011. Radon tracing of groundwater discharge into an Australian estuary surrounded by coastal acid sulphate soils. Journal of Hydrology 396, 246-257. JIF = 2.433. (ERA Rank *A)

Santos, I.R.; Lechuga-Deveze, C.; Peterson, R.N.; Burnett, W.C. Tracing submarine hydrothermal inputs into a coastal bay in Baja California using radon. Chemical Geology, 282: 1-10. JIF: 3.41. (ERA Rank A*).

2010

Santos, I.R.; Erler, D.; Tait, D.; Eyre, B.D. 2010. Breathing of a coral cay: Tracing tidally driven seawater recirculation in permeable coral reef sediments. Journal of Geophysical Research, 115: C12010. JIF=3.082. (ERA Rank A*)

Burnett, W.C.; Santos, I.R.; Hicks, R.W. 2010. Use of automated radon measurements for rapid assessment of groundwater flow into Florida streams. Journal of Hydrology, 380: 298-304. JIF = 2.433 (ERA Rank *A)

Santos, I.R., Peterson, R.N.; Eyre, B.D.; Burnett, W.C. 2010. Significant lateral inputs of fresh groundwater into a stratified tropical estuary: Evidence from radon and radium isotopes. Marine Chemistry, 121: 37-48 JIF =2.98 (ERA Rank A)

Peterson, R.N.; Santos, I.R.; Burnett, W.C. 2010. Evaluating groundwater discharge to tidal rivers based on a time series Rn-222 Approach. Estuarine Coastal and Shelf Science. 86:165-178. JIF = 2.07 (ERA Rank A)

Schmidt, A.; Gibson, J.J.; Santos, I.R.; Schubert, M.; Tattrie, K. 2010. The contribution of groundwater discharge to the overall water budget of two typical Boreal lakes in Alberta/Canada estimated from a radon mass balance. Hydrology and Earth System Sciences, 14: 79-89. (ERA Rank A)

Mwashote, B.M.; Burnett, W.C.; Chanton, J.; Santos, I.R.; Dimova, N.; Swarzenski, P. 2010. Calibration and use of continuous heat-type automated seepage meters for submarine groundwater discharge (SGD) measurements. Estuarine Coastal and Shelf Science, 87(1):1-10 JIF = 2.07 (ERA Rank A)

Sanders, C.J.; Santos, I.R.; Silva-Filho, E.V.; Patchineelam, S. R.; Schaefer, C. 2009. Recent 137Cs deposition in sediments of Admiralty Bay, Antarctica. Journal of Environmental Radioactivity, 101: 421-424. (ERA Rank C)

2009

Santos, I.R.; Burnett, W.C.; Dittmar, T.; Suryaputra, I.; Chanton, J. 2009. Tidal pumping drives nutrient and dissolved organic matter dynamics in a Gulf of Mexico subterranean estuary. Geochimica et Cosmochimica Acta, 73: 1325-1339.

Li, X.; Hu, B.X.; Burnett, W.C.; Santos, I.R.; Chanton, J.P. 2009. Submarine ground water discharge driven by tidal pumping in a heterogeneous Aquifer. Ground Water, 47(4): 558-568.

Santos, I.R.; Burnett, W.C.; Chanton, J.; Dimova, N.; Peterson, R.N. 2009. Land or ocean? Assessing the driving forces of submarine groundwater discharge at a coastal site in the Gulf of Mexico. Journal of Geophysical Research, 114, C04012.

Peterson, R.; Burnett, W.C.; Dimova, N.; Santos, I.R. 2009. A comparison of measurement methods for radium-226 on manganese fiber. Limnology and Oceanography: Methods, 7: 196-205.

Santos, I.R.; Burnett, W.C.; Chanton, J.; Dimova, N.; Mwashote, B; Peterson, R.N. 2009. Extended time series measurements of submarine groundwater discharge tracers (222Rn and CH4) at a coastal site in Florida. Marine Chemistry 113, 137â€"147

Ivar do Sul, J.A.; Rodrigues, O.; Santos, I.R.; Fillmann, G.; Matthiensen, A. 2009. Skin irritation and histopathologic alterations in rats exposed to lightstick contents, UV radiation and seawater. Ecotoxicology and Environmental Safety, 72: 2020:2024.

Santos, I.R.; Friedrich, A.C.; Sul, J.A. 2009. Marine debris contamination along undeveloped tropical beaches from northeast Brazil. Environmental Monitoring and Assessment, 148: 455-462.

2008

Santos, I.R.; Burnett, W.C.; Chanton, J. Mwashote, B; Suryaputra, I.; Dittmar, T. 2008. Nutrient biogeochemistry in a Gulf of Mexico subterranean estuary and groundwater-derived fluxes to the coastal ocean. Limnology and Oceanography, 53(2): 705-718.

Santos, I.R.; Niencheski, L.F.; Burnett, W.; Peterson, R.; Chanton, J.; Andrade, C.F.F. Milani, I.B.; Andrade, C.F.F.; Schmidt, A.; Knoeller, K. 2008. Tracing anthropogenically-driven groundwater discharge into a coastal lagoon from southern Brazil. Journal of Hydrology,353: 275-293.

Peterson, R.; Burnett, W.C.; Taniguchi, M.; Chen, J.; Santos, I.R.; Misra, S. 2008. Determination of transport rates in the Yellow Riverâ€"Bohai Sea mixing zone via natural geochemical tracers. Continental Shelf Research, 28(19), 2700-2707

Peterson, R.; Burnett, W.C.; Taniguchi, M.; Chen, J.; Santos, I.R.; Ishitobi, T. 2008. Radon and radium isotope assessment of submarine groundwater discharge in the Yellow River Delta, China. Journal of Geophysical Research. 113,

Santos, I.R.; Burnett, W.C.; Godoy, J.M. 2008. Radionuclides as tracers of coastal processes in Brazil: Review, synthesis, and perspectives. Brazilian Journal of Oceanography, 56(2): 115-131.

Santos, I.R.; Machado, M.I.; Niencheski, L.F.; Burnett, W.; Milani, I.B.; Andrade, C.F.F.; Peterson, R.; Chanton, J.; Baisch, P. 2008. Major ion chemistry in a freshwater coastal lagoon from Southern Brazil (Mangueira Lagoon): Influence of groundwater inputs. Aquatic Geochemistry,14: 133-146.

Sanders, C.J.; Santos, I.R.; Silva-Filho, E.V.; Patchineelam, S.R. 2008. Contrasting mercury and manganese deposition in a mangrove-dominated estuary (Guaratuba Bay, Brazil). Geo-marine Letters, 28: 239-244.

Santos, I.R.; Costa, R.C.; Freitas, U.; Fillmann, G. 2008. Influence of effluents from a wastewater treatment plant on nutrient distribution in a coastal creek from southern Brazil. Brazilian Archives of Biology and Technology, 51(1): 157-166.

2007

Santos, I.R.; Fávaro, D.I.T.; Schaefer, C.; Silva-Filho, E.V. 2007. Sediment geochemistry in coastal maritime Antarctica (Admiralty Bay, King George Island): Evidence from rare earths and other elements. Marine Chemistry, 107: 464-474.

2006

Silva-Filho, E.V.; Sella, S.M.; Spinola, E.; Santos, I. R.; Machado, W. ; Lacerda, L.D. 2006. Mercury, zinc, manganese, and iron accumulation in leachate pond sediments from a refuse tip in Southeastern Brazil. Microchemical Journal, 82: 196-200.

Sanders, C.J.; Santos, I.R.; Silva-Filho, E.V.; Patchineelam, S.R. 2006. Mercury flux to estuarine sediments, derived from Pb-210 and Cs-137 geochronologies (Guaratuba Bay, Brazil). Marine Pollution Bulletin, 52: 1085-1089.

Santos, I.R.; Silva-Filho, E.V; Schaefer, C.; Sella, S.; Silva, C.A.; Gomes, V.; Passos, M.J.A.C.R.; Ngan, P.V. 2006. Baseline mercury and zinc concentrations in terrestrial and coastal organisms of Admiralty Bay, Antarctica. Environmental Pollution, 140:304-311.

Friedrich, A.C.; Niencheski, L.F.; Santos, I.R. 2006. Dissolved and particulate metals in Mirim Lagoon, Brazil-Uruguayan border. Journal of Coastal Research, SI 39: 1036-1039.

2005

Santos, I.R.; Friedrich, A.C.; Wallner-Kersanach, M.; Fillmann, G. 2005. Influence of socio-economic characteristics of beach users on litter generation. Ocean and Coastal Management, 48: 742-752.

Santos, I.R.; Friedrich, A.C.; Barretto, F.P. 2005. Overseas garbage pollution on beaches of northeast Brazil. Marine Pollution Bulletin, 50(7): 782-786.

Santos, I.R.; Silva-Filho, E.V.; Schaefer, C.; Albuquerque-Filho, M.R.; Campos, L.S. 2005. Heavy metal contamination in coastal sediments and soils near the Brazilian Antarctic Station, King George Island. Marine Pollution Bulletin, 50: 185-194.

BOOK CHAPTERS

Milani, I.C.; Collares, G.L.; Akiyoshi, L.E.; Suzuki, S.; Tavares, V.E.; Niencheski, L.F.H.; Attisano, K.K.; Milani, M.R.; Andrade, C.F.F.; Santos, I.R. 2011. Groundwater resources and the coastal lagoons in southern Brazil. In: Bilibio, C.; Hensel, O.; Selback, J. (Eds), Sustainable water management in the tropics and subtropics ˆ case studies in Brazil. Fundação Universidade Federal do Pampa, Unikassel, PGCult/UFMA. ISBN 978-85-63337-20-7. 1211-1242.

2. Peterson, R.; Burnett, W.C.; Santos, I.R.; Taniguchi, M.; Ishitobi, T.; Chen, J. 2009. Boihai Sea coastal transport rates and their influence on coastline nutrient inputs. From Headwaters to the Ocean: Hydrological Changes and Watershed Management; Taniguchi et al. (eds) ; Taylor & Francis Group, London, ISBN 978-0-415-47279-1; pp. 659-664

1. Burnett, W.C., Santos, I.R., Weinstein, Y., Swarzenski, P.W. and Herut, B., 2007. Remaining uncertainties in the use of Rn-222 as a quantitative tracer of submarine groundwater discharge. In: W. Sanford, C. Langevin, M. Polemio and P. Povinec (Editors), A New focus on groundwater-seawater interactions. IAHS Publ. 312, Perugia, Italy, pp. 109-118.

UNREFEREED CONFERENCE PROCEEDINGS

Santos, I.R., Tait, D., Erler, D. and Eyre, B.D. 2009. Is submarine groundwater discharge an overlooked source of nutrients, acidity and anoxia to northern NSW estuaries? In: Proceedings of the 18th NSW Coastal Conference, Ballina. 11p.

TECHNICAL REPORTS

Burnett, W.C.; Peterson, R.N.; Santos, I.R. 2008. Groundwater flow estimates in streams and estuaries draining to the Indian River Lagoon, Florida. Prepared for Florida Environmental Protection Agency, 30p.

Updated: 30 April 2013