The Tasmanian coastal landscape includes rocky reefs, sandy beaches, sea cliffs, headlands, lagoons, river estuaries, harbours and open coast. The diversity of landforms and temperate conditions support a rich variety of terrestrial, intertidal and marine communities and species, some common, some threatened and others only found in Tasmania (endemic).
The interplay of coastal processes, such as wind and waves, with the different rocky and sandy landforms, combined with tidal ranges, rainfall, river discharge and climate, has moulded the Tasmanian coast. Vegetation too has played a very significant role in shaping many of these landscapes, such as plants stabilising soft sediments on dunes and in seagrass beds.
The Tasmanian coastal environment is vulnerable to the impacts of climate change, with significant areas of coast at risk of erosion from exposure to sea level rise and storm surge inundation.
More than 1440km of Tasmania's coastline has been identified as being at risk of coastal flooding, and more than 975km of shoreline are at risk of erosion, sand dune mobility, rock falls and slumping as a result of sea level rise and storm surges (Sharples 2006), with consequent impacts on natural values. Impacts on Tasmania's coastal landforms will be complex and variable, reflecting the diversity of coastal systems (DPIPWE 2010).
Changes in rainfall and temperature will change vegetation communities which will in turn modify these landscapes further, and rainfall changes and the potential for decreased flow in some river systems will modify estuarine environments.
Managing unstable coastal landforms such as dunes and beaches is not easy and technical advice is essential. Vegetation management is critical as coastlines alter rapidly when vegetation is destroyed and sediments become re-mobilised.
Inappropriate coastal works can easily be destroyed by waves, tides, currents or winds. In addition they can also cause problems in nearby coastal areas, such as erosion and movement of sand to places where it is not wanted. Coastal works must be undertaken with great care: many works in the past have been ineffective or caused needless damage to coastal values through poor planning and inappropriate techniques (Page and Thorp 2010).
For more information on coastal dune systems, beaches, estuaries, rocky shores, soft-rock shores and offshore islands, please see Chapter 6
of the Tasmanian Coastal Works Manual.