Tidal Extremes: Ecological Insights From Australia’s Dynamic Montgomery Reef

Large tidal swings expose a plateau-shaped reef around Australia’s Yawajaba island at low tide.

The Kimberley coast of Western Australia has one of the largest tidal ranges in Australia and the world. At Montgomery Reef, in Collier Bay, water levels drop sharply at low tide, allowing the plateau-shaped reef to emerge several meters above the water level.

Tidal shifts are particularly noticeable in this area because of the flat, shelf-like terrain along the Kimberley coast. This pair of images shows the reef when the tide was high (left) and low (right) in 2024. The high tide image was captured by the OLI-2 (Operational Land Imager-2) on Landsat 9 on April 21; the OLI (Operational Land Imager) on Landsat 8 acquired the low tide image on April 29.