Project title: The organic contribution to challenges in characterising the carbonate system in coastal waters
Researcher: Daniel Kerr
Increased release of anthropogenic CO2 to the environment has led to mounting concerns of drastic changes to seawater carbonate chemistry such as ocean acidification. This has spurred on the development and refinement of analytical methods used to determine the carbonate system parameters over the last few decades. Although analytical methods for carbonate system studies are well documented for pelagic waters, for heterogeneous coastal zones certain challenges to conventional analytical methods are introduced. Terrestrial discharges of freshwater carrying nutrients, organic and inorganic carbon present potential analytical interferences to conventionally measured parameters. Failure to account for or incorporate these interferences can lead to the propagation of errors in calculated carbonate chemistry data for coastal water bodies. This is of consequence as many littoral zones are susceptible to slight changes in carbonate chemistry, as well as being areas of aquacultural importance.
The purpose of this research is to characterise the main interferents to carbonate chemistry in coastal systems in order to minimise analytical errors and subsequent carbonate system calculation errors. This feeds directly into the underlying need to refine carbonate system calculation methods to accurately determine the status of carbonate chemistry in future climate scenarios. Organic molecules present in coastal waters can have significant inputs to total alkalinity (TA), which is one of the four main carbonate system parameters. Failure to account for this organic fraction of TA can lead to the propagation of errors in calculated carbonate system parameters as well as key descriptors of carbonate chemistry. If knowledge on the acid-base characteristics of the organic molecules is incorporated into TA analysis methods, the magnitude of the associated error is lessened. he objectives are to successfully establish a suite of carbonate system parameter analysis methods, as well as a modified TA analysis methods to characterise organic TA. This will be carried out alongside a suite of ancillary seawater chemistry analysis to investigate the drivers of carbonate chemistry in coastal waters.