Houtman Abrolhos

The Houtman Abrolhos (often called the Abrolhos Islands) is a chain of 122 islands, and associated coral reefs, in the Indian Ocean off the west coast of Australia, about eighty kilometres (50 mi) west of Geraldton, Western Australia.

The Houtman Abrolhos (often called the Abrolhos Islands) is a chain of 122 islands, and associated coral reefs, in the Indian Ocean off the west coast of Australia, about eighty kilometres (50 mi) west of Geraldton, Western Australia. It is the southernmost true coral reef in the Indian Ocean, and one of the highest latitude reef systems in the world. It is one of the world's most important seabird breeding sites, and is the centre of Western Australia's largest single-species fishery, the western rock lobster fishery. It has a small seasonal population of fishermen, and a limited number of tourists are permitted for day trips, but most of the land area is off limits as conservation habitat. It is well known as the site of numerous shipwrecks, the most famous being the Dutch ships Batavia, which was wrecked in 1629, and Zeewijk, wrecked in 1727.

In July 2019, the Houtman Abrolhos was declared a national park by the Western Australian government. The islands are an unincorporated area with no municipal government, subject to direct administration of the government of Western Australia.

Aboriginal people visited the islands during the Holocene, as indicated by the discovery on Beacon Island of a flaked stone artefact made from Eocene fossiliferous chert.

According to the surviving historical record, the first sighting of the Houtman Abrolhos by Europeans was in 1619, by the Dutch VOC ships Dordrecht and Amsterdam, only three years after Dirk Hartog made the first authenticated sighting of what is now Western Australia, and only 13 years after the first authenticated European voyage to Australia by the Duyfken, in 1606. Discovery of the islands was credited to Frederick de Houtman, Captain-General of Dordrecht, as it was Houtman who later wrote about the discovery in a letter to the directors of the Dutch East India Company:

"On the 29th do. deeming ourselves to be in an open sea, we shaped our course north-by-east. At noon we were in 29° 32' S. Lat.; at night about three hours before daybreak, we again unexpectedly came upon a low-lying coast, a level, broken country with reefs all round it. We saw no high land or mainland, so that this shoal is to be carefully avoided as very dangerous to ships that wish to touch at this coast. It is fully ten miles in length, lying in 28° 46."

The word Abrolhos is Portuguese, making the Houtman Abrolhos one of only two Australian places with a Portuguese name, the other being Pedra Branca in Tasmania. The noun abrolhos means 'thorn', and originally designated the spiny fruit of the bindii plant (Tribulus terrestris). Etymologically it is a contraction of the Portuguese expression abre os olhos ("open your eyes", i.e. to protect yourself). As a technical term this phytonym was later applied to caltrops (chevaux de frise), i.e. "spiked obstructions", and Portuguese sailors used the word to refer to offshore reefs.

Houtman thus named the islands using a Portuguese loanword that was current in the Dutch marine terminology of the time. John Forsyth states that the islands are named after the Abrolhos Archipelago off the east coast of Brazil, which was discovered and named by Portuguese navigators early in the 16th century. That position is supported by the fact that Houtman was familiar with the Abrolhos Archipelago, having sailed through it in 1598. Others assert that abrolhos was a Portuguese lookout's cry which, like many other Portuguese maritime terms, was taken up by sailors of other nationalities, becoming, by Houtman's time, a Dutch loan word for offshore reefs. Additionally, Frederick De Houtman had at least some grasp of Portuguese, having been sent by Amsterdam merchants to Lisbon from 1592 - 1594 with his brother Cornelis to learn about the Portuguese route to the Indies. Frederick also appears to have been a keen linguist, having published the first-known Dutch-Malay and Dutch-Malagasy dictionaries in 1603. He appears to have been fluent-enough in Portuguese that he might have used an evocative Portuguese word if it described the area better than any Dutch word did.

It has been argued by proponents of the theory of Portuguese discovery of Australia that the Portuguese name is evidence that the islands were charted by Portuguese navigators in the 16th century. Kenneth McIntyre, for example, claimed that Houtman was in possession of Portuguese maps of the west coast of Australia, and that he named the islands "abrolhos" in accordance with the name on those maps. Charting of the islands was previously credited to Jorge de Menezes, but the notion that Menezes visited Australia is now thoroughly discredited, and no other candidate has been proffered.The primary piece of evidence used to support the claim of Portuguese priority is the 16th century Dieppe maps, some of which are alleged to show the west coast of Australia, including an island at the position of the Houtman Abrolhos. That island is unlabelled on most of the Dieppe maps but, on Pierre Desceliers' 1550 map, it is labelled Arenes. In 1895, George Collingridge suggested that Arenes was a corruption of Abrolhos, but that was mocked by J.E. Heeres in 1898, and, according to J. S. Battye, "this suggestion can scarcely be regarded seriously. It certainly does not in any way add to the merit of the Portuguese claim".

Setting aside the Portuguese claims, the Houtman Abrolhos first appear on a map in 1622, on a little-known portolan by Hessel Gerritsz. They are unlabelled, however, being marked merely as a group of small circles. They are first named in print in Gerritsz' 1627 map Caert van't Landt van d'Eendracht, where they bear the label Fr. Houtman's abrolhos. On a map produced by Gerritsz the following year, they are labelled Houtman's Abrolhos.On British Admiralty charts, the islands are labelled Houtman's Rocks.

In 1629, some of the islands were the scene of a spectacular shipwreck and mutiny. The Dutch ship Batavia, under the command of Francisco Pelsaert, ran aground on her maiden voyage, and Pelsaert and some men went in an open boat to the town of Batavia (now Jakarta) to get help. A group of the men who stayed on some of the islets decided to terrorise and massacre many others, including women and children. When Pelsaert returned, many of the culprits were executed.

The Zeewijk was the last of the four Dutch East Indiamen to be wrecked on the west coast of Australia. The Ship's Council having made the inexplicable decision to disregard sailing orders and actually seek out the west coast of Australia, the ship ran onto the Half Moon Reef at about 7:30 pm on 9 June 1727. It did not break up immediately, and the heavy swell made evacuation impossible until 18 June. The longboat was launched on that day, and the crew and stores were thereafter gradually transferred to nearby Gun Island. Later, the men landed ten chests of money, containing 315,836 guilders and weighing a total of three tons.The crew of Zeewijk would be marooned in the Pelsaert Group for ten months, during which time they lived off seals, seabirds, eggs, and victuals salvaged from the wreck. They obtained some water from rainfall, but were forced to explore throughout the group in search of further supplies. A great many men died on the islands, including two boys who were accused of sodomy and marooned on separate islands of the Mangrove Group.On 10 July the longboat, fitted for a voyage and crewed with eleven men, was sent to Batavia to obtain help. It never arrived there, and nothing is known of its fate. Four months later the castaways began building a 60-foot (18 m) boat, sufficient to carry all the men and the money chests. Completed in March 1728 and affectionately named Sloepie ("little sloop"), it was the first ocean-going vessel built in Australian history. On 26 March 1728, the surviving men set sail for Batavia, arriving in Sunda Strait late the following month.

During Admiralty surveys of the north west coast in 1840, crew from HMS Beagle discovered a brass gun of about three pounds calibre, an iron swivel on which paint still adhered as well as numerous other artefacts signifying European occupation, on the largest island in the Pelsart Group. The commander, John Clements Wickham, named the place Gun Island and the passage between the Easter and Pelsart Groups, Zeewijk Channel. Later during the 19th century many islets were used by men collecting guano.

A lease to mine rock phosphate on the islands was obtained by Charles Broadhurst in 1884. After surveying the area he constructed a plant, stone jetty and tramways on Rat Island, a number of buildings on Rat, Gun and Pelsaert Islands and had over 40 Malay workers mining and processing the phosphate for export. Over 48,000 tonnes was shipped between 1884 and 1896.

As of 2012, the Australian Bureau of Meteorology has not published climatic data for the Houtman Abrolhos. However, an automatic weather station has been installed on North Island since 1990, and hourly measures of precipitation, air temperature, wind speed, wind direction, relative humidity and atmospheric pressure have been publicly available since then. Based on this and other data, researchers have put together a picture of the Abrolhos' climate.

The islands have a Mediterranean climate (semi-arid climate, or Bsh, under Köppen climate classification) with warm dry summers and cooler, wet winters. Mean temperatures range from 9.3 °C to 19.5 °C in July, and from 19.1 °C to 32.4 °C in February. These temperatures have a substantially smaller range than on the mainland: the summer temperature is typically a degree cooler, while winter temperatures are a good deal warmer. This is due to the influence of the ocean, and to the Leeuwin Current.

86% of the rain falls between April and September; on average there are 89 raindays, resulting in 469 millimetres of rain. The wettest month is June, when over 100 millimetres typically falls. In contrast, only about 70 millimetres can be expected to fall between October and March.

It is nearly always windy. During summer a high pressure ridge lies to the south, causing persistent winds from the southeast or southwest, at speeds exceeding 17 knots (31 km/h) almost half the time. During autumn and winter, the ridge moves northwards, increasing the atmospheric pressure over the islands, resulting in highly variable winds. Winter tends to produce both the strongest gales and the most frequent periods of calm.

In addition to these winds, there is daily pattern of land breezes in the morning, followed by the onset of south-westerly sea breezes in the afternoon. This pattern is caused by temperature differences between the land and the ocean, and is not as strong in the Houtman Abrolhos as on the mainland, but is present nonetheless.

Three classes of storm have been identified for the region. Brief squalls may occur between December and April. A tropical cyclone occurs in the area about once in three years, between January and April; these may generate extremely high wind speeds that are potentially destructive. During winter, extra-tropical cyclones sometimes pass south of Geraldton, generating winter gales with gusts of up to 35 metres per second, the wind direction from the northwest initially, then gradually moving around to southerly.