The Rowley Shoals is a group of three

atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical parts of the oceans and seas where corals can develop. Most ...

-like

coral Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important Coral ...

reefs A reef is a ridge or shoal of rock, coral, or similar relatively stable material lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic (non-living) processes such as deposition of sand or wave eros ...

south of the

Timor Sea The Timor Sea (, , or ) is a relatively shallow sea in the Indian Ocean bounded to the north by the island of Timor with Timor-Leste to the north, Indonesia to the northwest, Arafura Sea to the east, and to the south by Australia. The Sunda Tr ...

, about west of Broome on the northwestern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

n coast, centred on , on the edge of one of the widest

continental shelves A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

in the world. Each atoll covers an area of around within the rim of the reef, including the

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

s, while the land areas are negligible. They belong to

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. They all rise steeply from the surrounding ocean floor. To the northeast lie the

Scott and Seringapatam Reefs Scott and Seringapatam Reefs is a group of atoll-like reefs in the Timor Sea more than northwest of Cape Leveque, Western Australia, on the edge of the continental shelf. There are three or four separate reef structures, depending on whether S ...

which are located on the same undersea platform.

Naming and history

The Rowley Shoals were so named by Captain Phillip Parker King in 1818 in honour of Captain Rowley who first sighted the ''Imperieuse Reef'' in 1800. It is believed that the Rowley Shoals reefs have been visited by fishermen from

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

, from at least the mid-18th century. The fishermen were also collecting or hunting for Trepang (holothurians or

sea cucumber Sea cucumbers are echinoderms from the class (biology), class Holothuroidea ( ). They are benthic marine animals found on the sea floor worldwide, and the number of known holothuroid species worldwide is about 1,786, with the greatest number be ...

s),

turtle Turtles are reptiles of the order (biology), order Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Crypt ...

shell, trochus shell and

shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

fin. These early visitors apparently knew the Rowley Shoals as ''Pulau Pulo Dhaoh''. In later years, fishermen from

Roti Island Rote Island (, also spelled ''Roti'') is an island of Indonesia, part of the East Nusa Tenggara province of the Lesser Sunda Islands. According to legend, this island got its name accidentally when a lost Portuguese sailor arrived and asked a fa ...

, south of

Timor Timor (, , ) is an island at the southern end of Maritime Southeast Asia, in the north of the Timor Sea. The island is Indonesia–Timor-Leste border, divided between the sovereign states of Timor-Leste in the eastern part and Indonesia in the ...

, also visited the Rowley Shoals, which they knew as ''Pulau Bawa Angin''. The individual reefs were also given names, Mermaid Reef being called ''Pulau Manjariti'', Clerke Reef was ''Pulau Tengah'' and Imperieuse Reef was ''Pulau Matsohor''.

Description

*Mermaid Reef, the northeastern one of the three reefs at , is an atoll with a large lagoon enclosed by a rim of coral, which falls dry. There are many drying patches in the lagoon. On the northeast side of the reef, there is a passage, about 60 m wide, leading into the lagoon. Mermaid Reef rises steeply from the surrounding ocean floor, which is 440 m deep. The atoll was named in 1818 by Captain Philip Parker King, who discovered the reef and named it after his ship . *Clerke Reef (also called Minstrel Shoal), at , lies about 23 km southwest of Mermaid Reef. The reef has a length of about 15 km north–south, and a width of about 6 km. Near the northern end of the reef lies Bedwell Islet, a bare sand cay about 2 m high. On the eastern and western sides of the reef there are a number of boulders which fall dry. A narrow passage leads to a lagoon, with many detached coral patches within the reef. Clerke Reef rises steeply from the surrounding ocean floor, which is 390 m deep. It was also named by Captain Philip Parker King, after Captain Clerke, who had reported it from a whaler between 1800 and 1809. *Imperieuse Reef, at , lies about 35 km southwest of Clerke Reef and is the southwesternmost of Rowley Shoals. It is about 16 km in length north-south and has a width of about 8 km. On the southeastern edge of the reef there are numerous coral boulders, which rise about 3 m above the water mark. Large areas of the reef fall dry at low water and there are two lagoons, which each contain many coral patches within. Cunningham Islet, a small sand cay 3.7 m high and devoid of vegetation, is located close within the northern extremity of the reef, and is surrounded by a small lagoon, 93 m wide. The islet is the location of a

lighthouse A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways. Ligh ...

, Imperieuse Reef Light. Imperieuse Reef rises steeply from the surrounding ocean floor, which is 230 m deep. The reef was named by Captain Phillip Parker King after the ship (HMS Imperieuse) from which it was sighted by Captain Rowley in 1800.

Geological history

The Rowley Shoals, along with

Ningaloo Reef The Ningaloo Coast is a World Heritage Site located in the north west coastal region of Western Australia. The heritage-listed area is located approximately north of Perth, along the East Indian Ocean. The distinctive Ningaloo Reef that frin ...

, the

Ashmore and Cartier Islands The Territory of Ashmore and Cartier Islands is an uninhabited Australian States and territories of Australia#External territories, external territory consisting of four low-lying tropical islands in two separate reefs (Ashmore and Cartier), ...

and the

, are the remnants of a

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

aged

barrier reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. C ...

system which during the Middle Miocene around 16 million years ago spanned over along the northwest Australian coast, but which was largely drowned due to

tectonic subsidence Tectonic subsidence is the Subsidence, sinking of the Earth's Crust (geology), crust on a large scale, relative to crustal-scale features or the geoid. The movement of Plate tectonics, crustal plates and accommodation spaces produced by Fault (geol ...

during the late Miocene around 10 million years ago, with the Rowley Shoals having existed as isolated mounds since that time. Originally a fourth shoal existed to the southwest of the three existing mounds, but this reef was drowned by the Early Pleistocene, approximately 2.4 million years ago.

Conservation

Mermaid Reef is listed on Australia's Commonwealth Heritage List and all three reefs of the Rowley Shoals were registered on the former Register of the National Estate. The Shoals are the only known origin and home of several unusual species, including the Western Australian sculpin, and so are of major ecological value. * The Rowley Shoals Marine Park covers the Clerke and Imperieuse Reefs. Declared in 1990 and extended in 2004, the marine park is managed by the Department of Environment and Conservation (DEC) of Western Australia. * The

Mermaid Reef Marine Park The Mermaid Reef Marine Park (previously known as the Mermaid Reef Marine National Nature Reserve) is an Australian marine park in the Rowley Shoals, located approximately north-west of Broome, Western Australia. The marine park covers an are ...

protects the northeastern Mermaid Reef, it is an

Australian marine park Australian marine parks (formerly Commonwealth marine reserves) are marine protected areas located within Australian waters and are managed by the Australian government. These waters generally extend from three nautical miles off the coast to the ...

managed by

Parks Australia Director of National Parks is a Commonwealth corporate entity responsible for the management of a portfolio of terrestrial and marine protected areas proclaimed under the ''Environment Protection and Biodiversity Conservation Act 1999'' (''EP ...

. * The

Argo-Rowley Terrace Marine Park The Argo-Rowley Terrace Marine Park (formerly known as the Argo-Rowley Terrace Commonwealth Marine Reserve) is an Australian marine park offshore of Western Australia. It encompasses the protected areas of the Rowley Shoals, about north-west ...

is adjacent to, and encompasses the Mermaid Reef and Rowley Shoals marine parks.

Tourism

Since about 1977 charter boats based from Broome began operating

deep sea The deep sea is broadly defined as the ocean depth where light begins to fade, at an approximate depth of or the point of transition from continental shelves to continental slopes. Conditions within the deep sea are a combination of low tempe ...

fishing and

diving Diving most often refers to: * Diving (sport), the sport of jumping into deep water * Underwater diving, human activity underwater for recreational or occupational purposes Diving or Dive may also refer to: Sports * Dive (American football), ...

expeditions to the reefs and seas around. Since this time interest in the area has grown considerably and the Rowley Shoals has achieved a reputation for offering some of the best diving in Australia.

References

External links

*
Rowley Shoals Marine ParkSailing Directions, Vol. 175Underwater Photos by Mick Tait
{{Authority control Indian Ocean atolls of Australia Reefs of the Indian Ocean Reefs of Australia Islands of the Kimberley (Western Australia)