Ichaboe Island

In the early 19th-century Ichaboe and other islands of the South African coast witnessed the guano rush, equivalent of the American gold rush.^[2] The island was once used for sealing and following a visit in 1828 by Captain Benjamin Morrell and the discovery of bird manure to depths of more than 7 m, the focus turned to the quarrying of guano.^[3] At one time more than 400 ships anchored off the island and shanty towns housed thousands of workers. Large-scale scraping and bagging of "white gold" began in 1843 and peaked two years later. The value was so great that competition was fierce; murder was committed over harvesting rights, and two British warships were dispatched to restore order over what became known as the "Great Guano War".^[3][2] Britain took possession of the island on 21 June 1861.^[5] Guano has been taken off the island regularly, and in 1880 and 1881, Ichaboe Guano was claimed to be the "richest and most fertilising guano imported into England" containing 12 to 13% ammonia and 27 to 30% guano phosphates.^[6] The island was administered by the Cape Provincial Administration of South Africa and became a nature reserve in 1987. The islands were returned to Namibia in 1994 and are managed by the Ministry of Fisheries and Marine Resources (MFMR). Ichaboe, along with Mercury and Possession Islands, have permanent residents who partake in research and conservation of the seabirds.^[1] Scraping of guano continues with concessions granted during the 1980s and in 2000 a wall was put up around the perimeter of the island. The wall was built to prevent winds blowing the guano into the sea and has a few entry points for penguins to access the breeding areas.^[3]

Ichaboe regularly supports over 50,000 seabirds of at least eight species and is consequently one of the most important and densely packed seabird breeding in the world. The island holds 65% of the world's endangered Cape cormorant (Phalacrocorax capensis), despite the global population falling from 9,000 to less than 5,000 pairs over twenty years. Namibia is home to 4,000 of those pairs. The island is the most important location in the world for the near-threatened, crowned cormorant (Phalacrocorax coronatus), having 4% of the world's breeding population. Ichaboe also has large numbers of endangered African penguin (Spheniscus demersus) and the bank cormorant (Phalacrocorax neglectus), as well as the vulnerable Cape gannet (Morus capensis). Smaller numbers of kelp gull (Larus dominicanus) and African oystercatcher (Haematopus moquini) also breed here. Thousands of common tern (Sterna hirundo) and black tern (Chlidonias niger) may roost on the island.^[4]

Whales sighted off the island include the humpback whale (Megaptera novaeangliae) and southern right whale (Eubalaena australis). The cetaceans include, dusky dolphin (Lagenorhynchus obscurus), common bottlenose dolphin (Tursiops truncatus) and the endemic, Heaviside's dolphin (Cephalorhynchus heavisidii).^[4]