The southern continental coastline of Central Asia, stretching from Pakistan to Bangladesh, has remarkably little reef development. There are no true reefs recorded off of Pakistan, while most of the western and eastern coastlines of India are dominated by high levels of sediments, preventing reef formation. In the far southeast of India there is some reef development and there are a few important reefs around Sri Lanka. In stark contrast to these continental shores, the oceanic waters to the south, and around the Andaman and Nicobar islands in the east, abound with reefs.

Biogeographically this is region of transition. India's Andaman and Nicobar islands lie on the edges of insular Southeast Asia, the region of highest reef biodiversity it the world . The fauna on these reefs includes many species restricted to Southeast Asia, or which have the Andaman and Nicobar islands as the westernmost edge of their range. It is considered that these reefs in the Central Indian Ocean could provide a critical link of biodiversity between the eastern and western margins of the Indian Ocean.

Human pressures on the reefs in the region vary considerably. The reefs of the Chagos and parts of the Andaman and Nicobar Islands are among the least impacted coral reefs worldwide.. Studies on the water quality in the Chagos Archipelago suggest that these may be some of the least polluted waters in the world. By contrast the coral reefs in Sri Lanka and parts of mainland India are under enormous pressure. It is probable that some reefs have already been lost from these areas. The importance of reefs to the social and economic well-being of the region's people is widely recognized , and there are a number of efforts at the national level to restrict damaging activities and set aside areas for conservation.

India, despite its vast size, has only a few coral reefs off its mainland coast, mostly concentrated around the Gulf of Kutch to the northeast, and the Gulf of Mannar near Sri Lanka in the southeast. Reefs are highly developed in the more remote archipelagos of Lakshadweep and the Andaman and Nicobar islands. The distribution and status of any reefs outside these areas remains largely unknown.

The reefs and coral communities of the Gulf of Kutch are predominately patchy structures built up of sandstone or outer banks or around the small islands on the southern side of the gulf. They have adapted to extreme environmental conditions of high temperatures, fluctuating and high salinities, large tidal ranges and heavy sediment loads. As a result diversity in this region is low, with only thirty-seven hard coral species recorded and no branching corals.

The best developed mainland reef structures are located in the southeast, with fringing reefs occurring of Palk Bay, and on the coasts and islands of the Gulf of Mannar, including Adams Bridge, a string of reefs stretching across towards Sri Lanka. Diversity is high in this area, with one hundred and seventeen  hard coral species recorded, as well as a number of ecosystems including seagrass and mangrove communities. Unfortunately reefs in this region were recorded as rapidly deteriorating as early as 1971, associated with high levels of siltation and the removal of coral rock combined with cyclone impacts. Coral mining still occurs in the region, and mining from sand from the beaches is ongoing. Fisheries is thought to have a considerable impact, with some forty-seven fishing villages and a population of 50,000 people. Apart from the overexploitation of reef fish stocks there are concerns about other fisheries including sea fans, sea cucumbers, spiny lobsters, seahorses and shells for mother-of-pearl. About 1,000 marine turtles are taken annually and dugongs are also hunted.

A large proportion of the reefs in both the Gulf of Kutch and the Gulf of Mannar now fall with legally protected areas but these suffer from both weak management and virtually no monitoring. There are concerns that the Gulf of Kutch Marine National Park will be rescinded to allow for industrial development. The Lakshadweep Islands (Laccadives) are located about three hundred kilometers west of the southernmost tip of India. They are true atolls and related reef structures, built up over a volcanic base. There are twelve coral atolls with about thirty-six islands, about a third of which are inhabited.

The Andaman and Nicobar group consists of some five hundred islands. The islands fall into two clear districts :Andaman to the north and Nicobar to the south, separated by the one hundred and sixty kilometer wide Ten Degree Channel. There are fringing reefs along the coastlines of many of these islands. Species diversity here is higher than at any other reefs in India, with some two hundred and nineteen coral species recorded and over five hundred and seventy species of reef fish. At the present time many of the reefs are free from human impacts, and pollution remains generally low although this may change as the population on the islands grow.

Pakistan is believed not to have any true coral reefs. However coral communities on hard substrates are suspected, particularly in the west. Any such communities may be very similar to those described for southern Arabia.

Bangladesh, as with much of the Indian coast of the Bay of Bengal, has high levels of turbidity and freshwater influx that prevent reef development. There is one small area of coral reefs off the coast of St. Martin's Island, where some sixty-six hard coral species from twenty-two genera have been recorded.. These small reef areas are considered seriously threatened by sedimentation, cyclone damage, over fishing and anchor damage.

OFFICIAL, SCIENTIFIC & GOVERNMENTAL SITES:
2 coral reefs of India by Vineeta Hoon
Article on Andaman and Nicobar Islands coral reefs
Reef Base: Bangladesh
Reef Base: India
Reef Base: Pakistan
World Resources Institute: Coral reefs of the Andaman and Nicobar Islands

Sri Lanka is a large continental island off the southeast coast of the Indian sub-continent. Much of the coastline is dominated by high wave energy, and the southern and western coasts are further affected by considerable turbidity associated with numerous river mouths. Largely as a consequence of this, coral reefs  are not abundant in the coastal waters.

It has been estimated that fringing reefs of varying quality occur about two percent of the coastline, mostly along northwestern and eastern coasts. This statistic includes many coral communities which have developed on non-coral, or fossil reef, platforms. Most reefs could be described as fringing-type formations. Marine diversity is not as high among the reefs of the oceanic areas of the Indian Ocean, and coral cover is relatively low.

Nearshore fisheries are a critical activity in Sri Lanka, providing food, employment and income. Although coral reefs are not widespread, one estimate has suggested that up to fifty percent of the nearshore capture fishery depends directly on reef ecosystems. One other important economic activity is the collection of live fish for the aquarium trade. This has grown considerably over the past two decades: some two hundred and fifty species of reef fish and fifty invertebrates have been exported.

The threats to Sri Lanka's reefs are numerous and it is likely that the total reef area of this nation may have once been much larger. Many of the remaining reefs are highly degraded. Principle causes of degradation include very high levels of sedimentation arising from erosion of deforested land, poor agricultural practices and construction. Historically, coral mining has led to almost complete destruction of many reef along the south and southwest coast and may have similar impacts in the east. Although officially banned in 1983, mining in the sea continues in many areas where it is a traditional activity providing relatively high income employment.  Coral rock, taken from living and fossil reefs, is used as a raw material in lime production. In addition to direct destruction, coral mining leads to increased erosion and high turbidity over wide areas of the coastline. Further threats include to the remaining reefs arise from destructive fishing practices, including dynamite Fishing, uncontrolled exploitation of resources, and pollution arising from sewage and industrial activities. Although some legislation is in place controlling such activities as coral mining, enforcement is clearly a problem. Only two protected areas (Bar Reef and Hikkaduwa) are specifically designated for the protection of coral reefs, and management is either weak or absent.

OFFICIAL, SCIENTIFIC & GOVERNMENTAL SITES:
Article on destruction of Sri Lanka's coral reefs by reef mining
Reef Base: Sri Lanka
Sri Lanka's National Aquatic Resources Agency report on coral reefs

The Maldives are a spectacular chain of twenty-two coral atolls which run for some eight hundred kilometers north to south in the Central Indian Ocean. These include the largest surface-level atolls in the world: the area of Thiladhunmathi and Miladhunmadulu Atolls (with two names but a single atoll structure) is some 3,680 square kilometers, while Huvadhoo Atoll in the south is over 3,200 square kilometers.

There are an estimated 1,200 coralline islands, one hundred and ninety-nine of which are inhabited. The atolls have typical rims, with a wide reef flat, typically bearing a number of islands and sand cays broken by deep channels. The atoll lagoons range from eighteen to fifty-five meters in depth, and within these are a number of patch reefs and knolls, but also some reef structures known as faros which are common in the Maldives, but are very unusual elsewhere. These have the appearance of miniature atolls, with a central lagoon, and often bear small islands on their rim.

In terms of biodiversity, the Maldivian atolls form part of the "Chagos stricture" and so are an important link or stepping stone between the reefs of the Eastern Indian Ocean and those of the East African region. Diversity is very high and at least two hundred and nine scleractinian corals are recorded, with maximum diversity reported in the south. Over 1,000 epipelagic and shore fishes are recorded from the Maldives, a large portion of which are reef associated.

More than any other nation outside the Western Pacific, the Maldives is dependant on coral reefs for the maintenance of land area, food, export earnings and foreign currency for tourism revenues. Tourism is restricted to particular resort islands (eighty-eight in 1999), which are usually distinct from the local population centers. In 1998 there were almost 400,000 visitors, and diving and snorkeling were a major attraction for all of them. The impacts of tourism are localized, but may be significant in certain sites. Impacts include direct diver and anchor damage, interruption of sand movements through the building of jetties, localized eutrophication from direct sewage discharge into the lagoons, and thermal pollution from desalination plants. Solid waste disposal is a problem in most areas. Undoubtedly the greatest concern for this entire nation is the impact of climate changed. Coral bleaching and mortality have already caused significant problems: in the future such events will be exacerbated by sea-level rise, and may be further compounded by reduced calcification rates on surviving corals.

OFFICIAL, SCIENTIFIC & GOVERNMENTAL SITES:
Global Coral Reef Alliance report on Maldives' coral reefs
Reef Base: Maldives


The British Indian Ocean Territory covers a very large area of reefs and islands, also known as the Chagos Archipelago. There are some fifty islands and islets, although the total land area is only sixty square kilometers, there is a vast area of reefs. These include five true atolls (Blenheim Reef, Diego Garcia, Egmont, Peros Banhos and Salomon), a mostly submerged atoll (Great Chagos Bank, the largest atoll structure in the world at some 13,000 square kilometers) and a number of submerged banks (including Speakers Bank, Pitt Bank and Centurion Bank).

The reefs and islands are highly isolated -the nearest reef structures are those of the Maldives, some five hundred kilometers to the north, which the nearest continental land mass is that of Sri Lanka, more than 1,500 kilometers away. With some two hundred and twenty scleractinian species, the reefs of the Chagos are among the most diverse known for hermatypic corals in the Indian Ocean. There are a number of species of coral that are found only here, and this is most certainly due to the isolation of the reefs.

A number of islands and their associated reefs have been declared protected areas. These cover substantial areas of reef and they are occasionally patrolled by military personnel. Overall, partly as a result of their history and continuing isolation, but further supported by current management measures, the reefs of the Chagos probably represent some of the most pristine and best protected in the Indian Ocean.
 

Extracted and adapted from The World Atlas of Coral Reefs, by Mark D. Spalding, Corinna Ravilious and Edmund P. Green, published by the University of California Press . For more complete and in-depth coverage of the topics presented in this webpage, I recommend highly purchasing a copy of this beautifully illustrated book. Just click on the University of California Press link above to do so.