Australia’s coastal zone holds tremendous national significance. It contains many of the country’s most prized environmental and ecological assets, some of which are World Heritage listed, and accommodate habitats and species found nowhere else on Earth. The biological and landscape diversity of the coast is immense, encompassing a wide range of climatic, geological and oceanographic regions that contain interacting terrestrial, estuarine and marine ecosystems. Australia’s Indigenous history and culture are closely tied to the coast, which hosts invaluable heritage sites, and is fundamental to past and contemporary Indigenous practices.
In addition to its environmental and heritage values, the coast is central to our economy, lifestyle and cultural identity. Most Australians choose to live near the coast for its recreational amenities and economic opportunities—a trend that shows no sign of slowing. With this population density comes environmental pressures, and the danger of ‘loving our coast to death’. Major pressures include habitat loss for urban development, pollution, resource extraction, invasive species and unsustainable fishing. Mitigating the effects of these pressures through proper management is essential to ensure the ecologically sustainable use and development of the coastal zone.
The coastal zone of Australia is notoriously difficult to define, as its boundaries depend on the biological or environmental components in question. Urban centres can extend tens of kilometres inland and still be considered coastal, while some areas of vegetation diminish in coastal characteristics within a few kilometres of the shoreline. There is also difficulty in defining the shoreline for some parts of Australia, particularly in the north-west of the country, where high tides and low-lying land cause the intertidal zone to extend many kilometres inshore.
For this report, we will follow the definition used in SoE 2011, which considered the coast to be the zone of interface between terrestrial, aquatic and marine environments, while acknowledging that the size of that interface differs between components. For analyses that track quantitative trends on coastal land, we use a 50 kilometre buffer inland from the shore, noting that the strength of maritime influence will vary between places, and between biota and environmental components. Subtidal waters seawards of bays and estuaries are covered in the Marine environment report.