Saltwater intrusion - a natural process


Supervising Scientist Note series
Contact officer: M Saynor
Supervising Scientist, October 2004

About the note

Saltwater intrusion is a major coastal management problem confronting the conservation of freshwater wetlands, flora and fauna all over the world.

Over the last 50 years, tidal creeks in the Alligator Rivers Region in Northern Australia have rapidly extended inland to low-lying freshwater wetlands, turning them saline. This process, called saltwater intrusion, is natural and leads to significant ecological and morphological changes to coastal freshwater environments.

Saltwater intrusion leads to the loss of freshwater vegetation and the spread of saline mudflats into previously vegetated areas. This can lead to the destruction of crocodile breeding grounds and magpie geese habitat and can impact on the ability of the local Aboriginal people to hunt and gather food. Saltwater intrusion also affects the high conservation values of coastal freshwater wetlands, as it reduces the diversity of flora and fauna.