Goyder Institute blue carbon research projects: synthesis report

Blue carbon refers to the carbon that is captured and stored in coastal vegetated ecosystems(Figure 1). This happens through two main pathways: 1)Carbon dioxide (CO2) is taken up (sequestered) directly from the atmosphere by coastal vegetated ecosystems during photosynthesis and converted into above and below ground plant material2)Organic matter is produced by plants and trapped and buried in the sediment/soil, where it can be stored for millennia (Lo Iacono et al. 2008).Mangrove, tidal saltmarsh and seagrass ecosystems are very effective carbon stores because they constantly accrete sediment. This prevents carbon saturation, which means they have the capacity to continually sequester carbon from the environment. In addition, the sediment in these tidal systems is waterlogged and anoxic, which decreases the breakdown and release of carbon back to the environment(Mcleod et al. 2011). Blue carbon ecosystems make a significant contribution to the global carbon cycle, with organic carbon (Corg) sequestration rates and storage periods orders of magnitude higher than in many terrestrial ecosystems (Mcleod et al. 2011). This makes them of significant interest for national and regional climate change mitigation strategies together with ongoing, high rates of global blue carbon ecosystem loss. Degradation and loss of blue carbon ecosystems decreases the carbon storage capacity of the coastal carbon sink and results in CO2emissions, while their conservation, restoration and creation have the potential to increase carbon capture and storage (Lovelock et al. 2017), mitigate climate change (Duarte et al. 2013), support carbon finance opportunities (Thomas 2014)and provide numerous other ecosystem services (also called co-benefits; Barbier et al. 2011).