Australia is beginning to see the impact of the pressures of climate change on our coasts, and pressures are expected to grow substantially in coming decades. These will add stress to systems that are already stressed by a range of human activities. Recent climate-related stress resulted in a major dieback of mangroves in the north.

When multiple pressures occur at the same place and time, there is potential for them to interact and exacerbate impacts. Such is the case in areas of the coast with dense human settlement, agriculture or industry.

Nationally, there are currently 1257 floral and 425 faunal species listed as threatened under the Environment Protection and Biodiversity Conservation Act 1999, many of which occur on the coast. Several protected species are now stable or improving, demonstrating the benefits of good management. Crocodiles, for example, are increasing everywhere within their natural range, and mangroves have been increasing in extent in most parts of Australia. In contrast, migratory shorebirds are deteriorating, despite protection in Australia, likely because of the destruction of critical habitat in other countries along their migratory route. Continued decline of saltmarsh and seagrass habitats is a significant concern, given their role in coastal productivity, biodiversity maintenance, sediment stabilisation and carbon sequestration.

Although there are many experts on the Australian coastal environment, almost none are confident to make assessments for the entire coast. This reflects the absence of nationally consistent, or coordinated, environmental health assessments for the coast. It also speaks to the diversity of Australia’s coast, and the inherent differences between processes operating in tropical and temperate regions.

Satellite data have been used for the first time to assess trajectories of estuarine water quality and coastal vegetation change across the entire coast of Australia. These approaches use the newly developed Australian Geoscience Data Cube (a national collation of Landsat imagery) to assess trends in coastal environments across multiple decades.