![]() Very similar biological effects of mining were found in two studies, one in the Maldives (Brown and Dunne, 1988 Dawson-Shepherd et al., 1992) and another in Tanzania (Dulvy et al., 1995). ![]() It is estimated that in the Maldives, up until 1988, at least 200 m 3 of coral rock had been removed from reefs in North Male Atoll for use in the construction industry (Brown and Dunne, 1988). The coral is then broken up into irregularly shaped coral nodules which are the directly incorporated into the building trade. Corals are broken up and transported to the destination and left for a period in the open for the action of sun and rain to clean the rock of its living inhabitants and leach out the salts (Figure 3). In the Maldives, the mining of coral rock is carried out by a specific group of islanders from Maamigili in Alifu Atoll working from local fishing craft or dhonis. Favored corals include the massive genera Porites, Platygyra, Goniastrea, Favia, and Favites as well as the branching genera Acropora and Pocillopora (Brown and Dunne, 1988). Throughout South Asia, the manner of harvesting coral rock is very similar, involving manual collection with iron bars (Figure 2). The actual choice of sites is dependent on several factors, which include the prevailing weather conditions dictated by the monsoon in the Indian Ocean and the proximity of the final destination of the coral. ![]() Generally, all living coral is extracted from shallow waters on leeward reef flats and reef edges and in the Maldives from the coral rims of faroes or ring reefs in depths of approximately 2 m of water. Conversely, in the Maldives coral rock was much more important in the construction industry in the mid-1990s (Figure 1) than coral fragments, while in Tanzania both fossilized limestone and live coral were used in building work. In India, the collection of coral fragments greatly exceeded the collection of coral ‘stones’ mainly because of its ease of collection and the reduced demand for the latter. In the mid-1990s, in Sri Lanka the greatest proportion of coral rock (42%) was derived from fossil reefs inshore, whereas live coral collection represented 12% and coral rubble (collected from the beach and reef flats) 30% of the total harvest. These differences are reflected in the total harvest of coral products and also in the site and method of exploitation. While the construction industry is a major user of corals in the above-mentioned countries, it is clear that there is wide variation in the exploitation of specific coral products by different countries. In the offshore islands, it is estimated that over 10–24 tons of shells and corals are collected from the reefs per year in an activity that involves ten people collecting once or twice a week (Tomascik et al., 1997). Similarly, in West Sumatra branching and massive corals are extracted to sell as decorative materials for house walls. Coral ‘stones’ extracted from areas such as the Gulf of Mannar, India, are used as building blocks or in road construction and as source material for house decorations. In India, corals (coral fragments or ‘challi’ rather than coral ‘stones’) are also used for the production of lime with lime kilns in the Tuticorin area of southern India, exporting lime all over the country to meet the demands of paper and sugar industries, leather tanning and bleaching, mortar production, and white wash paint. In Sri Lanka, corals are primarily used in the construction industry for production of mortar and plaster with subsidiary uses as lime in soil improvement and in the ceramic and cement industry. At Mafia Island, in Tanzania two forms of coral were extracted in the early to late twentieth century for both local and commercial construction (Dulvy et al., 1995) these were fossilized limestone and living reef coral. Early photographs taken by Agassiz in Malé in the Maldives in 1903 show houses constructed of coconut leaves and available timber, but by the mid-late tewntieth century construction of houses, boundary walls, groynes, and breakwaters with coral blocks was commonplace (Brown, 1997b). The use of coral rock as a construction material in many countries in the central Indian Ocean has had a long history, particularly in the building of mosques, temples, and shrines. ![]() Coral mining has caused extensive degradation of reefs in a number of countries, which include India, Maldives, Sri Lanka, Tanzania, and the Philippines (Brown, 1997a). ![]()
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