A/Prof. Luke Mosley1, Jason Quinn2, Prof. Sabine Dittmann3
1University Of Adelaide, , , 2Department for Environment and Water, , , 3Flinders University, ,
Achieving carbon sequestration benefits during tidal wetland restoration is an emerging area of importance in relation to climate change mitigation and carbon market opportunities. Coastal (“blue”) carbon dynamics during a tidal restoration trial in a 38 ha pond at the Dry Creek salt field are described. The aim of the trial was to restore suitable geochemical conditions for recovery of coastal ecosystems, and assess carbon sequestration. Installation of four tidal pipes and gates reconnected the pond to the tidal creek in July 2017. During the trial, measurements of the organic carbon stock in soil and vegetation, and greenhouse gas fluxes, were undertaken for the purposes of carbon accounting using the Verified Carbon Standard (VM033). The investigations showed a net gain of soil organic carbon stock following tidal re-connection, which could be partly attributed to influx of seagrass wrack. Methane gas fluxes were negligible, and could be excluded from further carbon stock assessments. Sediment accumulation rates were highly variable across the strata and between the trial pond and reference areas. Saltmarsh vegetation rapidly colonised the pond following tidal re-connection. The organic carbon fraction for saltmarsh and above and below ground vegetation biomass showed that while greatest carbon capture will be in mangrove, saltmarsh can also be a further important contributor. The potential to generate carbon sequestration benefits and credits during larger-scale coastal restoration activities is discussed.
Associate Professor Luke Mosley is a researcher in the School of Biological Sciences at the University of Adelaide. Luke had a passion for the sea and coastlines from an early age and gained his PhD from the University of Otago (New Zealand) on the aquatic geochemistry of estuaries and catchments. Luke worked as principal scientist for South Australia’s Environment Protection Authority for over 10 years. Luke is also Deputy Director of the Acid Sulfate Soil Centre at the University of Adelaide, President of Soil Science Australia, and a long term member of the Scientific Advisory Group for the Coorong and Lower Lakes.