Coasts and Coastal Wetlands
Sea level rise will impact the region’s coastline through increasing inundation and erosion as well as direct impacts on specific coastal habitats and biodiversity. Coastal wetlands are very vulnerable to climate change. Increased drought frequency and intensity, decreases in freshwater inputs, rising sea levels and increases in coastal storm surges may all impact these important ecosystems. These conditions may also change the character of coastal wetlands through a reduction in size, conversion to dryland or a shift from one wetland type to another (e.g. brackish to saline). Under hotter and drier conditions and reduced inflows, acid sulphate soils in coastal wetlands will face an increased risk of being exposed. The retention of coastal wetlands will require planning approaches which allow for the migration of wetland communities in order to avoid significant loss in both extent and character.
The Corangamite region includes 175 kilometres of Victoria’s coastal fringe and approximately 450 square kilometres of in-shore coastal waters (Corangamite CMA, 2009). The region’s coastal extremities are Point Wilson on the north-west shores of Port Phillip Bay and Peterborough in the south west.
The Corangamite region has a diverse range of natural assets that are features of the area’s coastline. The marine and coastal environments of the region include rocky reefs, pelagic waters, sand beaches, intertidal mudflats and coastal wetlands (with a connection to the sea). Equally diverse habitats include kelp forests on shallow rocky reefs, seagrass communities and mangroves.
The condition of the region’s coastal environment is generally healthy due to low levels of nutrients, turbidity and bio-contaminants. Some larger areas of coastline within public land have been actively managed for conservation purposes over many years and are considered to be nearly intact. Threats to the region’s coasts are largely attributed to activities in adjacent landscapes and catchments.
The Victorian Government, Corangamite CMA and local coastal Committees of Management are working closely with the City of Greater Geelong and Borough of Queenscliffe to undertake more detailed local coastal hazard assessments at several priority locations along the coast on the Bellarine Peninsula and within Corio Bay.
This assessment will test a range of methods to analyse the impacts of sea level rise as well as provide practical information for planners and coastal asset managers to make decisions at a local scale. It is hoped that this work, once completed, will continue to be developed for other areas within the region.
Coastal wetlands will be very vulnerable to climate change. Increased drought frequency and intensity, decreases in freshwater inputs, rising sea levels and increases in coastal storm surges may impact these important ecosystems. These conditions may also change the character of coastal wetlands through a reduction in size, conversion to dryland or a shift from one wetland type to another e.g. brackish to saline. Under hotter and drier conditions, as well as reduced inflows, acid sulphate soils in coastal wetlands have increased risk of exposure.
Coastal wetlands highly vulnerable to climate change include those found in the Lower Barwon, Gellibrand and Aire rivers. These wetlands occur in low lying areas and are more susceptible to sea level rise and storm surges.