Description of the study areas

The Lakshadweep islands is densely populated with 60,595 people (2001 census, Source: Department of Information Publicity and Tourism, Lakshadweep) living on 32 km2 of land (Elliot, 1976). The Lakshadweep islands consist of the northern inhabited Amindivi (or South Kanara) islands, including Ameni, Kadmat, Chetlat, Kiltan, Bitra and Agatti (Fig. 1). The southern or Malabar islands include Minicoy, Kavaratti (the capital), Kalpeni and Androth.

The Lakshadweep islands have about 3000 artisanal fishermen (Bakus et al., 1994). The chief occupation of the islanders is fishing and the locals are highly dependent on bait fish (such as sprats, pomacentrids and apogonids) which they use for pole and line tuna fishery (Bakus, et al 2000). Species like Spratelloides delicates and S. japonicus are much sought after for live bait (Kumaran, et al., 1989). The annual fish catch is 2000 to 5000 metric tons (mostly tuna 70% and shark) (Jones 1986). Smoking and sun-drying of fish is common. The reef also serves as a food source (rays, perches, carangids, belonids, halfbeaks) when tuna fish catches are low, and there is a shell-craft industry (Wells and Sheppard, 1988).

Tourism is strictly restricted to Kadmat, Agatti and Bangaram, with the latter having a tourist resort open to foreign tourists. Indian tourists are allowed to have only limited access to the Lakshadweep islands.

The islanders are dependent on the mainland for all essential supplies including fuel, vegetables and packaged foods and infrastructure. In the absence of sufficient subsidies on conventional construction materials, the islanders find it a simpler option to harvest the lagoons for coral which they use for housing, roads, and other construction (Wells and Sheppard, 1988; Koya, S.I., Per.Com.). Though the collection of coral from lagoons has been largely regulated, the collection of coral shingle from the shore continues unabated, resulting in an ever-weakening beachfront (Pillai, 1996).

Dredging activities in lagoons around many inhabited islands has created severe disturbances in the past, the removal of the reef front in some areas to allow the passage of large boats has permanently affected current flows in and out of the lagoon (Pillai, 1983; Pillai 1996). This activity has damaged large areas where healthy reefs once thrived.

Kavaratti
Kavaratti (Fig 2), the capital Island situated at 10°-33’ North Latitude and 72°-38’ East Longitude and 404 kms from Cochin has a land area of 3.63 sq.km. At the northern end, the lagoon is shallow and the coral growth is found to be healthier. Kavaratti is the most centrally located island in this archipelago.

At Kavaratti the southwestern atoll, shows excessive deposits of silt at some areas which lead to dead colonies at the top portion of the lagoon reef. The three spots selected at Kavaratti are Dolphin centre (Northwest), West entrance and Wind mill (South). During survey at Kavaratti, the tide and visibility was good (16-19m).

Kadmat
Kadmat (Fig. 3) located at 11°-13’ Latitude and 72°- 47’ East Longitude and 407 kms from Cochin. It has a land area of 3.12sq.km with 8kms long and 550m wide at the broadest point. It is the longest island and has a very large lagoon on the western side with abundant coral growth. The three spots selected were: Ship wreck (Northwest), Main entrance (West) and Tourist hut (South). Mostly the sea was calm with good visibility to 18m during diving at Kadmat.

Agatti
Agatti (Fig.4) is located at 10°-51’ North Latitude 72°-11’ East Longitude and 459kms from Cochin. It has a land area of 2.7sq.km with 6kms long and 1000m wide. Three spots selected were: Main entrance (Northwest), West entrance, and Japanese garden (Southeast). The weather was windy and cloudy during the survey at Agatti. Visibility was observed to 20m.