[2] The islands formed approximately 10,000 years ago after large fluctuations in sea levels caused erosion on large areas of the continental shelf during periods of glaciation.
[1][3] Well preserved Tamala limestone geological features can be found on all of the Turquoise Coast islands, with supra-tidal hard coral fossils being found on the Beagle Islands.
[1] The islands are home to the largest population of Australian sea lions in Western Australia, The breeding colony is estimated to be between 150 and 250 animals depending on the breeding cycle.
[4] East Beagle island is also home to the tree-like form of the Nitre Bush, an important habitat for sea lions when pupping.
[1] In 1905 a boat was reported as being wrecked near the islands[5] and in 1934 a fisherman drowned after being swept overboard.