‘Blue Carbon’ habitats (saltmarsh, mangroves, seagrass) are known to store significant quantities of carbon globally. The biogeochemical conditions in these habitats are conducive to long-term carbon retention, with carbon-rich sediments continuing to accrete over long periods of time, anoxic saline conditions slowing down the rate of decay of organic material and saline soil conditions minimising the release of methane to the atmosphere.
Whilst the area of coastal saltmarsh in Australia has been estimated at over 1.3 million hectares, relatively little is known of the quantity, character or spatial variability of carbon stocks in these wetlands. For example, it is not known to what extent carbon stored is autochthonous (resulting from primary production within the saltmarsh) or allochthonous (imported from adjacent ecosystems or elsewhere in the catchment). My project will combine field sampling and laboratory analyses to assess the contribution of such carbon sources at the local scale.
I will also compare results from saltmarsh ecosystems in different geomorphic settings within estuaries to improve our understanding of carbon dynamics at broader scales. By comparing results in distinct geomorphic settings (e.g. marine tidal delta versus fluvial delta) I hope to better characterise estuarine carbon stocks and improve our understanding of the broader carbon transportation processes in estuaries.
Improved understanding of the processes driving carbon sequestration in coastal saltmarshes as well as improved methodologies for measuring carbon dynamics within and between ecosystems will also help to inform regional and global carbon management and potential carbon offset schemes.
Kelleway, J., Williams, R. J., and Laegdsgaard, P (2009). 'Mapping, assessment and monitoring of saltmarshes' in Australian Saltmarsh Ecology. N. Saintilan, CSIRO Publishing, Collingwood, Victoria: 211-229. ISBN: 9780643093713
Kelleway, J. (2005). Ecological Impacts of Recreational Vehicle Use on Saltmarshes of the Georges River, Sydney. Wetlands (Australia) 22:2, 52-56.
Laegdsgaard, P., Kelleway, J., Williams, R. J., and Harty, C. (2009). 'Protection and management of coastal saltmarsh' in Australian Saltmarsh Ecology. N. Saintilan, CSIRO Publishing, Collingwood, Victoria: 179-210. ISBN: 9780643093713
Mazumder, D., Iles, J., Kelleway, J., Kobayashi, T., Knowles, L., Saintilan, N., and Hollins, S. (2010) Effect of acidification on elemental and isotopic compositions of sediment organic matter and macro-invertebrate muscle tissues in food web research. Rapid Communication in Mass Spectrometry 24: 2938-2942.
Williams, R. J., Allen, C. B., and Kelleway, J. (2011) Saltmarsh of the Parramatta River-Sydney Harbour: determination of cover and species composition including comparison of API and pedestrian survey. Cunninghamia 12(1): 29–43.
Stacey M Trevathan-Tackett, Jeffrey Kelleway, Peter Macreadie, John Beardall, Peter Ralph, Alecia Bellgrove Ecology (2015) Comparison of marine macrophytes for their contributions to blue carbon sequestration.
ABC Radio 702 interview Jeff Kelleway 702 2015JUN01.m4a
Study backs seaweed's carbon capturing potential UTS Newsroom