There are approximately 650km of mostly pristine coastlines and beaches in the region that provide critical habitat for a variety of marine and terrestrial species, essential ecosystem services, natural resources, and immense amenity and cultural value to the region’s communities. Torres Strait coastlines and beaches are increasingly subject to frequent tidal inundation, coastal erosion and extreme weather events associated with climate change.
These thin strips where the land meets the sea are a critical interface of significant environmental and cultural value in the region (e.g., intertidal fringing reefs and sea grass beds, nesting coastal birds and marine turtles, subsistence fishing, plant and animal resources). Rocky coastlines are home to a range of birds, plants and marine organisms which are typically only found in these environments. Beaches of the central coral cays formed from ground-up coral fragments and other marine organisms are especially vulnerable to ocean acidification.
Extensive research has been conducted into understanding coastal erosion and tidal inundation impacts across the region over the past decade. Knowledge of coastal vegetation cover and species assemblages has also been improved through ongoing biodiversity surveys on inhabited and uninhabited islands.
What is already happening?
Many beaches across the region are experiencing increased erosion as sea level increases. This includes loss of mature littoral forests and strand shorelines on coral cay islands. Coastal infrastructure such as barge ramps and channels has altered natural sand movement with impacts on adjacent beaches.
Coastal protection engineering infrastructure is being installed on six islands most exposed to tidal flooding and erosion. These structures provide increased protection for coastal communities but have flow-on impacts on adjoining coastal processes and loss of amenity and habitat value.
High resolution aerial mapping of priority beach areas is being undertaken by TSRA, and rangers in some communities are monitoring changes in beach profiles.
What could happen?
Engineered coastal defences buy communities some time but are not a long-term solution to sea level rise impacts. Longer term strategies will involve migrating people and infrastructure out of the coastal hazard zone, and strategic revegetation efforts.
Coral cays have some capacity to grow with increasing sea levels, but this depends on the rate of rise and the health of the corals needed to supply the coralline sand.
Coastal ecosystems are likely to be severely impacted by tidal flooding and increased storm driven erosion. Sites of cultural significance may be lost, along with vegetation cover, shade trees, fauna habitat and important cultural resources.