The Rowley Shoals are a chain of coral atolls on the edge of one of the widest continental shelves in the world.
The three pear-shaped atolls have shallow lagoons inhabited by corals and abundant marine life. Each atoll
covers an area of around 80 to 90 square kilometres. The three shoals are strikingly similar in dimension,
shape, orientation and distance apart. Each atoll is north-south orientated, pear-shaped, with the narrow end
towards the north. The Shoals rise with nearly vertical sides from very deep water. Mermaid Reef, the most
northerly, rises from about 440 metres, Clerke from 390 metres and Imperieuse from about 230 metres.
The Rowley Shoals were named in 1818 by Captain Philip Parker King, who first
described their relative positions. He discovered and named the most
north-easterly of the trio Mermaid Reef, after his ship. He gave the middle shoal
the name Clerke Reef after Captain Clerke, who had reported it from a whaler
sometime between 1800 and 1809. The south-western shoal was dubbed
Imperieuse Reef after the vessel from which it was sighted by Captain Rowley in
1800.
According the Captain H.V. Howe, a former pearler on the north-west coast at the turn of the century, some of
the pearling luggers working out of Cossack from the mid-1800s to about 1930 regularly called at the Rowley
Shoals and Scott Reef, to the north, to collect beche-de-mer and fish, before returning their Indonesian pearl
divers to Kupang in Timor.
From about 1977 charter boats based from Broome began operating
deep sea fishing and diving expeditions to the area. Since this time
interest has expanded enormously and the Rowley Shoals is fast gaining
a reputation for offering some of the best diving in Australia. Today the
Shoals rank among the most remote and pristine marine areas in the
world. Lying on the very edge of Australia's continental shelf, they are
regarded as the most perfect examples of shelf atolls in Australian waters.
Clerke and Imperieuse Reefs form the
Rowley Shoals Marine Park, declared in
1990 and managed by the WA Department of Conservation and Land
Management (CALM). The nearby Mermaid Reef Marine National Nature
Reserve is managed by the Australian Nature Conservation Agency (ANCA) with
the assistance of CALM. Both Coastwatch and the WA Fisheries Department
also assist with management of the Shoals.
The coral atolls of the Rowley Shoals are famed for their almost untouched coral
gardens, giant clams and other shellfish. Giant potato cod and maori wrasse wait to
be hand fed and follow divers around, while colourful reef fish show little fear, and
trevally, mackerel and tuna hover in schools. An exceptional 233 species of coral and
688 species of fish inhabit the shoals--including many species not found on
nearshore coral reefs. There are at least 28 species of staghorn coral alone. As well
as being inhabited by a number of species found nowhere else, the coral and fish
communities of the Rowley Shoals are unique in their composition, and in the relative abundance of species.
The marine communities of the Rowley Shoals are more characteristic of south-east Asia than any other WA
reefs.
The outside walls of the shoals are alive with soft corals in every imaginable colour. At low tide the water
becomes ponded within the reef walls, the water gushing over them like waterfalls. At high tide, the reefs
disappear beneath the sea, with only the sandy islands of Clerke and Imperieuse visible.
