Project Abstract

The biophysical assessment of coral reefs along the Lakshadweep covering three islands, Kavaratti, Kadmat and Agatti, was done during February 2005 using Line Intercept Transect method mainly to set up a baseline on biophysical reef monitoring by generating database. Also the abundance and distribution of corals and associated biota was recorded along with the characterization of the benthic communities at these sites. Information on the current damage and potential threat to the reef colonies was also collected from published works and reported.

Three spots were selected in each island and the coral percentage coverage and diversity were surveyed using SCUBA on reefs at depths ranging from 4 to 10 m. Total coral cover was reported to be 80.8%. Acropora spp. (47.3%) dominated in all the three islands followed by the non Acropora species (33.5%) and a total algal cover of 16.1% is recorded. Twenty one genera of corals are reported with the major corals like Fungia spp. Porites spp., Montipora spp., Pavona spp., Goniopora spp., Favites spp., Favia spp., Astreopora spp., Pocillopora spp., Stylophora spp., Psammocora spp. and Goniastrea spp. In addition to these Siderastrea sp. is a new record from Kavaratti and Kadmat while Seriatopora sp. is new from Kavaratti island. Stress tolerant species Porites are common in all the islands. Encrusting corals are healthy and largely unaffected tabular is seen. The major benthic animals other than the corals observed were algae, polychaetes, clams, barnacles, starfishes, sea cucumbers, sponges, octocorals (dominated by Alcyonians and Nephthids more than gorgonids) and black corals. Butterfly fishes, surgeon fishes, damselfishes, parrot fishes, wrasses, emperors, snappers, groupers, eels, barracudas, triggers and rays were recorded in abundance.

No apparent bleaching and COT related mortality of coral was observed in the three islands, though major threats are reported from available literatures. Degradation of dead coral through bio-erosion and wave action has led to increased sand and rubble formation, increasing stress through abrasion and suffocation which was observed in most of the survey. The database includes benthic survey details, bibliographic and historical information.

The overall state of coral growth was found to be good in all the three islands and the need for strict and sustained reef monitoring is stressed to keep the tract of any mortality, recovery and to detect the changes in the functioning of reef and associated biota especially fishes.