Situation
Mercury Island is situated 800 metres offshore in Spencer Bay, 110 kilometres north of Lüderitz. The island is only 750 metres long (North-South) and about 270 metres wide, reaching a height of 38 metres above the sea. Steep, rocky, without vegetation, covered in a thick layer of bird guano, and riddled with a number of caves (one of which completely bisects the island), Mercury Island's name comes from the shaking that reverberates through the island during westerly wave action. Its nearest neighbour and like bird habitat is Ichaboe Island, about 65 kilometres to the south. Ichaboe and Mercury are the two most important island seabird breeding sites along the Namibian coast. Today the island has a permanent population in the form of a two-person bird research station. The station sits on the remains of a bird guano mining dock on the northeast side of the island. [1]
Mercury Island's three hectares are home to 16000 penguins, 1200 gannets, and 5000 cormorants, [2] which range tens of kilometres out to sea, and return to the island to breed. [3]
History
An American sealing captain, Captain Benjamin Morrell, in 1832 wrote in his (ghost-written) memoirs, A Narrative of Four Voyages, that the guano deposits on Ichaboe Island were 25 feet deep. He averred that a $30,000 investment would produce in two years a profit of "from ten to fifteen hundred per cent." [6]
Liverpool businessman Andrew Livingston investigated the claim, with the result that a guano rush developed. Exploitation began in 1841, and between 1843 and 1845 some 450 boats lay off Ichiboe as their crews retrieved over 300,000 tons of guano. The rush extended to Mercury and other Namibian islands. The guano extraction destroyed the habitat that had drawn breeding seabirds that had created the deposits.
Captain Owen Owens and 19 crew members from SS Point Pleasant Park landed on Mercury on 2 March 1945 after a German submarine had sunk their vessel on 23 February. The fishing vessel Boy Russell rescued them, taking them to Luderitz, South West Africa.
Seabirds are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period, and modern seabird families emerged in the Paleogene.
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The Little Chalky Island, part of the Big Green Group within the Furneaux Group, is a 5-hectare (12-acre) unpopulated granite island, located in the Bass Strait, west of the Flinders Island and south of Chalky Island, in Tasmania, in south-eastern Australia. The island is part of the Chalky, Big Green and Badger Island Groups Important Bird Area.
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The Tasman Island, part of the Tasman Island Group, is an oval island with an area of 1.2 square kilometres (0.46 sq mi), lying close to the south-eastern coast of Tasmania, Australia. The island is located in the Tasman Sea, situated off the Tasman Peninsula and is contained within the Tasman National Park.
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The Sir Joseph Banks Group is an archipelago in the Australian state of South Australia located in Spencer Gulf about 20 kilometres (12 mi) off the eastern coast of the Eyre Peninsula. It consists of 21 islands of which eighteen are in the Sir Joseph Banks Group Conservation Park while the surrounding waters are in the Sir Joseph Banks Group Marine Park. It is considered to be an important seabird breeding site.
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Malgas Island is a small, 8.3 hectares, uninhabited island lying in the northern part of the entrance to Saldanha Bay, in the Western Cape province of South Africa. It lies about 800 metres (2,600 ft) from the mainland in the Benguela upwelling system. It is circular in shape and flat, with the highest point about 9 metres (30 ft) above sea level. It is known for its large breeding colony of Cape gannets.
Halifax Island is a small rocky island about 100 m (330 ft) from the mainland, near Lüderitz in Namibia. It is the third most important breeding site for African penguins in Namibia.
Ichaboe Island is a small rocky island off Namibia's Diamond Coast. It is recognised by BirdLife International as an Important Bird Area (IBAs) for its seabird breeding colonies.
