Elizabeth & Middleton Reefs
Elizabeth Reef and Middleton Reef are a pair of isolated oceanic
platform reefs separated from one another by 45 km of deep oceanic waters. They are located in the northern Tasman
Sea, around 95 km north of Lord Howe Island and 555 km off the New South Wales coast,
due east from Coffs Harbour. They are unique in that they represent the southernmost platform reefs in the world.
Despite their high latitude both reefs display a rich and diverse marine flora and flora, brought about by their
location in an area where tropical and temperate ocean currents meet.
The two reefs of are of similar size and shape with Middleton Reef measuring 8.9 km by 6.3 km; Elizabeth Reef is slightly smaller at 8.2 by 5.5 km. The reefs are largely awash, with only two small sand cays being emergent at high tide. The largest cay, Elizabeth Island, found on Elizabeth Reef measures around 400 m in length and is up to 400 m in width. The smaller cay, known as The Sound, located on Middleton Reef, measures 100 m by 70 m. Both barely emerge 1 m above the high water level. At low tides much of the reef flat is exposed by the receding waters.
Middleton Reef takes the form of a distinctly kidney-shaped structure. On the north side is an entrance in to the interior lagoon which is protected by the hard algal ridge and extensive reef flat that forms the outer margin to the reef. Its shallow lagoon has a sandy to silty bottom that contains numerous patch reefs and areas of coral pavement.
The twin reefs sit atop a feature known as the Lord Howe Rise — a ridge of volcanic origins that runs from New Zealand northwest across the Tasman Sea. Nearby Lord Howe Island is the the only other emergent part of the ridge. They are protected by the Elizabeth and Middleton Reefs Marine National Nature Reserve, covering 1,880 km². The reserve was proclaimed in 1987 to protect these important and fragile marine ecosystems as well as with the aim of conserving the rare and endangered Black Cod (Epinephelus daemelli).
