in Sri Lanka - Ministry of Environment

Extensive coral growth is limited to a depth of about 12 meters in Sri Lanka due to the turbiditythat exist in coastal waters. The Gulf of Mannar has the most extensive shallow coral reefsin Sri Lanka (Swan 1983; Rajasuriya & De Silva, 1988). Fringing coral reefs are common inthe northern, eastern and southern coastal waters. A few offshore patch reefs are found inthe western coast between Chilaw and Colombo that are located ca. 10 to 20 kilometers fromthe shore line and at an average depth of 20 meters. Sandstone and rock reef habitats arewidespread on the continental shelf. Generally, the hard coral cover is low on these substratescompared to extensive coral habitats (Rajasuriya & De Silva, 1988; Rajasuriya, Ohman &Johnstone, 1998; Rajasuriya, Ohman & Svensson, 1998). However, in some areas the diversityof hard corals is higher on sandstone reef habitats than on extensive coral habitats. Extensivehard coral reefs tend to be dominated by a few species belonging to branching and tabulateAcropora species, Echinopora lamellosa or foliose Montipora species and massive corals ofthe families, Faviidae and Poritidae.ThreatsThe major widespread threat to corals is from climate change. In 1998 large extents of shallowwater corals became bleached and many reefs were damaged extensively. Their recoveryis variable and even within a single reef area such as the Bar Reef individual patch reefshas shown different levels of recovery (Rajasuriya 2005, 2008). Coral bleaching with someregularity has been observed recently, especially on reefs in the east and north. In 2010 therewas severe bleaching of the coral reefs in the Pigeon Island National Park and Dutch Bay inTrincomalee. These reefs are heavily degraded and have not shown good signs of recovery.However such bleaching events appear to be localized as some fringing reefs at Kutchchavelilocated north of Trincomalee was not bleached during the same period. Crown of Thornsstarfish populations dwindled after the 1998 large scale coral bleaching, but an increase intheir numbers has been observed recently in Trincomalee.The 2004 Tsunami caused serious damage to some coral reefs mainly in the eastern andsouthern region. This physical damage still remains and combined with other forms of impactsincluding coral bleaching and human induced damage continue to degrade the quality ofcoral reefs. The use of destructive fishing methods including blast fishing is still widespread,especially in the eastern and northwestern coastal waters. Over harvesting of species suchas herbivorous reef fish, the Humphead wrasse (Cheilinus undulatus) that feed on juvenileCrown of Thorns starfish and many other species that are important for the maintenance of theecological balance of coral reefs continue to take place. Pollution from coastal developmentand industries has affected all near shore reefs in Colombo and reefs in the vicinity of majorcities in the southern coast. Unplanned development of tourist facilities along the coast hascaused beach pollution and contributed to the damage of near shore reefs due to expansionof tourism related activities beyond the carrying capacity of an area and through direct impactssuch as trampling of corals by visitors. Most of the damage is caused by Sri Lankan visitorswho disregard the advice given to them by local authorities.377