Tidal reconnection of a salt pond that has been isolated from the salt field has commenced and investigations on carbon sequestration through ecological restoration are now well underway. Blue Carbon has been identified as a key carbon offset opportunity for South Australia’s policy of transition to a carbon neutral economy. The significance of this project lies in a market-ready approach to obtain carbon credits from the restoration of salt fields. The outcomes from this Goyder Institute for Water Research project will document whether salt field restoration can contribute to carbon neutrality and net zero emissions through bio-sequestration.
Using an interdisciplinary approach, the team is studying the carbon stocks and sequestration, reduction of greenhouse gas emissions, revegetation and co-benefits of salt field restoration. The project will generate data through a range of field studies that will allow a high certainty and accuracy of the carbon stock inventory, enabling a Tier 3 assessment according to the Intergovernmental Panel on Climate Change (IPCC). The data obtained from the pond and adjacent reference area will feed into development of accredited carbon accounting methods. The project is thus not only establishing a proof of concept, but also the data base for registration of the salt field to obtain credits under the verified carbon standards and assist achieving the carbon neutral policies of South Australia.
“It is extremely exciting to see the first saltmarsh and mangrove plants growing inside the tidally reconnected pond,” researcher Jason Quinn from DEWNR said, adding, "We are hoping that the project will demonstrate that reconnecting salt fields to tidal flow will lead to a re-establishment of saltmarsh and mangrove vegetation and with it, carbon abatement and other co-benefits."
Samples have been collected to characterise the baseline condition of carbon concentrations, which were quite variable between different sites and depth layers. Surface elevation tables have been set up inside the pond and deeper sediment samples taken for assessment of sediment accumulation rates over short and long (decadal) time periods. Measurements are undertaken for saltmarsh and mangrove above and below ground biomass in defined elevation strata. Preliminary results for greenhouse gas emissions indicate lower methane emission in the re-connected pond compared to an adjacent salt pond.
“We are looking forward to the further analysis and calculating the carbon sequestration,” Project Leader Professor Sabine Dittmann from Flinders University said. “This project is ground-breaking in providing knowledge on the best mechanism and processes of salt field restoration that will have implications for carbon capture and other ecosystem services of tidal wetlands for South Australia and elsewhere.”