[3][1] The shallow waters within about 15 metres (49 ft)[3][1] of the edges of the lake are home to thrombolites, estimated to be about six million years old.
They were given preliminary protection under the Aboriginal Heritage Act and the Djeran Fish Festival was subsequently organised as a celebration.
[a] In the 1960s it was used as part of an urban drainage scheme; the Water Board constructed inlet and outlet drains.
[4] The lake is home to the Swan River goby (Pseudogobius olorum), eastern mosquitofish, sea mullet, goldfish and yabbies.
[6][7] The lake was used as a source of fresh water by the local indigenous Noongar people, as well as the settlers of the Swan River Colony.