It has extensive fringing sedgeland typical of the Swan Coastal Plain, and is a major breeding site, migration stop-over and semi-permanent drought refuge area for waterbirds.

These dunes are the result of the accumulation and subsequent distribution of beach sands along successive shorelines from a series of marine incursions combined with the prevailing westerly winds.

Palaeobotanical studies show that the lake sediments are 30–40,000 years old, making them the oldest found in Western Australia.

The fringing zone around the edge is characterised by the introduced bulrush Typha orientalis and the sedge Baumea articulata.

It regularly supports more than 1% of the national population of four shorebirds: red-capped plover (with up to 1,000 counted), black-winged stilt (3,000), red-necked avocet (3,000), and curlew sandpiper (2,500).

The most numerous are Australian shelduck (with up to 1,600 counted), Pacific black duck (4,500), grey teal (6,000), Australasian shoveler (2,000), and Eurasian coot (7,000).