02 April 2020
This research and the associated synthesis brochures were undertaken by Hub researchers from Project 2.11: Establishment of the National Centre for Coasts and Climate – Phase 1
Australia is a coastal nation. We live, work and play on or near the coast, with coastal environments also providing a range of services for important Australian industries such as tourism, fisheries and aquaculture.
Climate change will affect our coastal environments through rising sea levels, changes in wave behaviour, extreme rainfall, storms and increasing ocean temperatures resulting in impacts such as coastal erosion, inundation and marine heatwaves.
Natural, created or restored habitats such as oyster reefs, mangroves and salt marshes have the potential to provide coastal protection as well as enhance biodiversity and other ecosystem services, including food provision and improved water quality. These ‘living shorelines’ also have the potential to play an important role in climate mitigation and adaptation due to their ability to sequester carbon and reduce the threats of coastal erosion and flooding. However, there are still many uncertainties regarding the use of natural habitats for coastal protection and carbon sequestration.
The National Centre for Coasts and Climate, through the Earth Systems and Climate Change Hub, has undertaken research to improve knowledge and resources on blue carbon ecosystems, coastal erosion and eco-engineering coastal defence solutions.
Three brochures have now been developed which synthesise this research:
Blue carbon ecosystems and climate change
Australia has large expanses of mangrove, salt marsh and seagrass habitats, collectively known as blue carbon ecosystems. Blue carbon ecosystems accumulate and store more carbon per unit area than tropical forests. They therefore have great potential to help mitigate climate change. However, uncertainties exist around what proportion of the carbon buried in blue carbon ecosystems originates from within the system (and can therefore count towards climate change mitigation) or have been transported from terrestrial ecosystems (where it has already been accounted for in the terrestrial carbon cycle).
What we’re doing
Our researchers are improving methods for measuring carbon stocks and accumulation rates and are developing methods for quantifying sources of carbon in blue carbon ecosystems. This includes developing and applying methods to better monitor root distribution and root turnover, using 3D mapping systems to track changes in above-ground carbon stocks over time, better understanding the impacts land management practises have on carbon stocks, and developing guidelines outlining steps to achieve accurate estimates of sediment carbon stock.
Why we’re doing it
Our research is helping to tackle the many challenges and uncertainties which need to be resolved before blue carbon ecosystems can be included in any emissions trading scheme. Our findings will assist coast mangers and policy makers to manage blue carbon ecosystems for ecosystem services, such as climate change mitigation, with greater confidence.
Read more: Climate change and blue carbon in Australia
Coastal erosion under a changing climate
Six percent of the open coast of Victoria has experienced some level of shoreline retreat over the past 30 years. Rising sea levels due to climate change are likely to cause accelerated erosion of many Australian coastlines, with consequences for coastal infrastructure, communities, ecosystems and coastal leisure activities. Knowledge gaps remain around the amount of long-term shoreline retreat that may occur under climate change. Greater understanding is therefore required of historical shoreline dynamics over decadal time frames and the influence of sediment supply, vegetation and human infrastructure on this process.
What we’re doing
Our researchers are working on improving understanding of the variability and underlying drivers of coastal erosion. We focused on the open-coast of Victoria to investigate the historic shoreline changes of the Victorian coastline; the changes in beach and dune morphology when eroded; and the role of vegetated systems (coastal dunes) in mitigating erosion.
Why we’re doing it
Our research will lead to improved predictions of future erosion, specifically in relation to climate change impacts, and will provide important information and data to inform coastal management activities. Improve understanding of the drivers of coastal change through developing an index of Victorian dune resilience to coastal erosion will also provide valuable information and data for coastal managers.
Read more: Coastal erosion under a changing climate
Eco-engineering and restoration of coastal habitats in Australia
Climate change is increasing the risk of erosion and flooding of the coastal environment. This, coupled with increases in population along the coast, is likely to lead to enhanced exposure of coastal communities to existing and future coastal hazards. Globally, coastal habitats that include salt marsh, mangroves, seagrass, shellfish and coral reefs have suffered significant declines, which have resulted in a loss of important ecosystem services, such as biodiversity provision, water purification, carbon filtration and coastal defence. Nature-based coastal defence is the creation or restoration of coastal habitats through hybrid and soft ecological engineering to recover shoreline protection services along with other ecosystem services.
What we’re doing
Our researchers are working on ways to develop more sustainable and adaptive methods to protect the coast through applying nature-based solutions to enhance the resilience of our coastal communities. We have undertaken research to investigate the role of different natural habitats in reducing wave energy at specific locations on the Victorian coastline; tested hybrid coastal protection solutions in Port Phillip Bay; and conducted a survey of Victorian coastal residents in an effort to assess the socio-economic cost-benefits of nature-based approaches compared to artificial coastal protection structures.
Why we’re doing it
We’re using this current information, and previous knowledge, on coastal defence solutions to develop guidelines for the wider application of nature-based coastal defence in Australia. The guidelines will assist policy makers and coastal managers in applying the best coastal protection solutions for their coastline to support resilient and adaptive coastal ecosystems and communities.
Climate change and coastal science to inform policies and decisions
Climate change and coastal science information is critical to help deal with the impacts of climate change on our coastal environments.
Research by the National Centre for Coasts and Climate, though the Earth Systems and Climate Change Hub, is improving knowledge and developing methodologies and approaches to better understand current and future coastal hazards and to trial nature-based coastal projection solutions to inform on-ground coastal management actions.
More research on blue carbon ecosystems, coastal erosion and eco-engineering solutions for coastal protection is continuing under the ESCC Hub through Project 5.9 Natural habitats for coastal protection and carbon sequestration – Phase 2 of the National Centre for Coasts and Climate.
For more information
Professor Stephen Swearer, National Centre for Coasts and Climate, University of Melbourne