Detailed report of work done on the project

The Lakshadweep Archipelago (71˚-74˚ E longitude and 8˚-12˚30’ N latitude) consists of 12 coral atolls with 36 Islands, 3 reefs and 5 submerged banks situated at the northern end of the Laccadive-Chagos ridge, 225-450 km west off the Kerala coast (Fig.1). The coastline of Lakshadweep islands is 132km (Wafar, 1999). These islands vary in size from 0.1sq.km (Bitra) to 4.8sq.km (Androth) and are surrounded by 4,200 sq. km of lagoon, raised reefs and banks. The population on the 10 inhabited islands ranges from 100 on Bitra Island to 10,000 on Kavaratti. All inhabited Lakshadweep islands are protected by an outer reef which encloses a shallow lagoon with the exception of Androth, which is exposed on all sides (Jones and Kumaran, 1980).

The islands receive heavy southwest monsoonal rain ranging between 156 and 225 cm/year with most of it falling between June and September (Pillai, 1971) with air temperatures ranging between 20.1˚ to 32.9˚C. The lagoons have surface seawater temperatures of 22° to 28° C, salinities of 36 to 39.4 ppt, and oxygen levels between 1 and 15 ml/l (Girijavallaban et al., 1989). The reefs enclose the islands in extensive lagoons and protect them from storm and other disturbances of the sea. The island complexes around India, in contrast, show healthy reef growth and support high species diversities.

In contrast to the low terrestrial biodiversity, the marine biodiversity of Lakshadweep is abundant and spectacular with many characteristic species. The lagoons and sea around the islands support several species of endangered marine fauna. There are fundamental gaps in basic distribution and status information for most reef areas in the region. Although taxonomy, natural history and productivity of coral reefs in India have been studied, there is virtually no modern experimental ecological research (Bakus et al., 2000). The coral reef ecosystem of these islands is perhaps the least studied one and hence the necessity to take up studies related to coral fauna and associated organisms in Lakshadweep is vital.

CMFRI made a notable study on the marine fauna of Lakshadweep in 1989. Then in 1998, Department of Science and Technology (DST),, Lakshadweep in association with the Global Coral Reef Monitoring Network (GCRMN South Asia) undertook the first ever Reef Check survey in India at Kadmat island, Lakshadweep (Rajasuriya et al., 1999a; Koya, S.I. and Wafar, per. com.). Various other agencies and individuals (Arthur, 1999, Rajasuriya et al., 2000a, WWF, 2000, Gandhi & Mathew, 2000, Singh et al., 2000, DOD 2001, Callum, 2002, Anon. 1991) have conducted studies/ assessment of coral reefs from different perspectives from time to time. Despite several decades of coral reef research in India, the state of our present knowledge of these systems is still limited.

The other factors limiting the reef development being turbid waters stirred by monsoonal systems, and a heavy human population and development pressure along the entire coastline (Bakus et al., 2000). Coral reef conservation value is related to biodiversity of corals, invertebrates and fishes (Edgar et al., 1997), fisheries potential and habitat for rare or endangered species.

However, no benchmarks for the coral reef data from monitoring perspective exist and existing data is not comparable across the sites both in time and space. Also, no systematic institutional monitoring mechanism of reefs exists to analyse the changes in reef ecosystem over a period of time leading to fundamental gaps in the basic distribution and status information for most reef areas in this region. Hence, the present biophysical monitoring survey at Lakshadweep was taken as an immediate measure.