Wetlands deliver a range of critical ecosystem services, including water filtration and purification, providing vital food and habitat resources for numerous species of recreationally and commercially important fish species, and providing significant protective buffers from extreme weather events. Recent research has also highlighted the impressive role that coastal wetlands play in capturing and storing atmospheric carbon dioxide – often far in excess of their terrestrial counterparts. Much of the carbon stored in coastal wetlands is in the soil, which represents a challenge to account for it under the fledgling Carbon Farming Initiative (CFI).
Many coastal wetlands, particularly saltmarsh, occur along the intertidal estuarine fringe – a zone that unfortunately bears the brunt of significant and increasing pressures from numerous recreational and commercial uses. When coastal wetlands are lost or damaged, their ability to deliver critical ecosystem services, including that of carbon storage, are also lost. Wetland Care Australia, Australia’s leading non- government, non-profit wetland conservation organisation, has a number of projects currently underway that are improving the health of coastal and floodplain wetlands.
Restoring their natural ecosystem function restores the wetland’s ability to store carbon, however, the rate at which newly restored systems are able to do this is largely unquantified. Globally, it is estimated that 430 megatonnes(one megaton is equivalent to one million tonnes) of carbon is stored in the upper 50cm of tidal saltmarsh soils, with an estimated annual average storage rate of 210 g/ cm2/yr-1(Chmura et al., 2003). There has been minimal research done on Australian saltmarsh, but estuarine wetland carbon stores from one study done in the Hunter region of NSW, estimated that there was 0.7–1 megatonnes of carbon in the Hunter estuary (Howe et al 2009).
Wetland Care Australia’s Mid North Coast Saltmarsh Recovery project, funded by the NSW Environmental Trust, focuses on building the resilience of saltmarsh communities between Coffs Harbour and Port Macquarie, NSW. A large component of this project will be repairing the significant amount of vehicle damage that has occurred at these sites from unrestricted vehicle access, and repairing the critical upper 50cm layer that stores most of the carbon. Results from previous projects in the far north coast have shown that, once the original soil levels are restored, these systems can quickly regenerate if given the right conditions, thus reinstating their carbon storage potential as well as the numerous other ecosystem services they deliver.
Wetland Care Australia has undertaken twenty five saltmarsh site assessments in key areas, and mid-2014 will see the project move into the on ground works phase. The restoration work will be supported by a series of workshops targeting stakeholders, farmers and landowners to help them understand the benefits of repairing and protecting their saltmarsh areas.
Wetland Care Australia has also partnered with the Southern Rivers Local Land Services to run a series of workshops for farmers for the Realising the Potential: Connectivity and Carbon Storage in NSW Coastal Wetlands project, funded by the Australian Government’s Biodiversity Fund. This project will strengthen wetland habitat resilience and health through revegetation, establishing buffer zones, removing barriers to flow and controlling pests in32 priority catchments.
In addition, Wetland Care Australia’s keystone project, Delivering Biodiversity Dividends for the Barrata Creek Catchment is making significant headway into restoring carbon to wetland soils in North Qld via an integrated suite of on ground works. The Barratta Creek catchment forms the main artery of the Bowling Green Bay wetlands, the only Ramsar site in north Queensland. Barratta Creek is one of the most high integrity floodplain creek systems on the developed east coast of Queensland. Since the introduction of intensive irrigated agriculture, the creek and wetlands have suffered serious impacts through a lack of active management and understanding, including invasive aquatic and terrestrial weeds, hot frequent fire regimes and excessive nutrient rich tailwater flows. Now in its second year, the project, funded by the Australian Government’s Biodiversity Fund, has united multiple stakeholders in tackling some of the major threats facing this system and improving biodiversity outcomes and carbon storage through integrated catchment based management.
Find out more about the approach the project is taking by reading the extended story on the Rivers of Carbon website…