Environmental Deterioration in Lakshadweep and Need for Conservation of Living Resources
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Geol. Surv. Ind. Sp/. Pub. No. 56 2001 : pp 171-1 74 ENVIRONMENTAL DETERIORATION IN LAKSHADWEEP AND NEED FOR CONSERVATION OF LIVING RESOURCES C.S. GOPINADHA PILLAI AND P.A. THOMAS Central.Marine Fisheries Research Institute Kochi INTRODUcnON Calophyllum inophyllum and Thespesia. The The Lakshadweep Archipelago is located on the ground vegetation is seasonaL Casuarina is intro Laccadive - Chagos ridge, believed to be the sub duced. Coconut plantation, fringes the sandy marine extension of the Aravalli mountains. The shores and the interior of the islands. In recent various atolls rise from a depth ranging from 1500 to past many garden plants and vegetables are intro 4000 m. The Lakshadweep Archipelago consists of duced into the atoll. Destruction to the natural veg 12 atolls, 3 reefs and 5 submerged banks, all of coral etation consequent to agricultural activities was sig formations. The total land area is about 32 sq km. nificant. Grazing pressure from the introduced cattle The height of islands vary from 1 to 1.4 m from and goats is also causing destruction to vegeta MSL. Except Amini all islands have a shallow la tion. Mangroves are scarce, except at some pock goon. The windward side is with rubble shores ets in Minicoy. while the lagoon leeward side is with a sandy shore. RESUME OF MARINE RESEARCH IN The reef flats are mostly fossilised with algal ridges LAKSHADWEEP and believed to have been shaped in the Holocene Early investigations on the marine habitats and period. The climate is warm and humid. The Archi reefs of Lakshadweep were those of Alcock (1902) pelago is exposed to both NE and SW monsoons and Stanley Gardiner (1903-06). During the post and the average annual rain fall is about 1640 mm independence period, scientists ofthe C.M.F.R. In (Data based on Minicoy, the southern-most atoll). stitute, Kochi and N.LO., Goa carried out a series of The atolls are located in the cyclonic belt and often impressive studies on the living resources of severe storms are experienced. Ten of the atolls are Lakshadweep as well as the human and natural im inhabitated and the area of inhabitated islands alto pact on the ecosystems. Detailed accounts of these gether is about 26.2 sq km. A recent estimate by studies are provided by James, 1989 and James et remote sensing (Shai, 1994) has shown that the ex al., 1986 and Bakus, 1994. tent of reef area in Lakshadweep is 140.1 sq km. The On the agricultural sector, Central Plantation total population in lakshadweep according to the Crops Research Institute (lCAR) is doing a lot of latest census is 51 ,681 . The average density of popu research, especially on coconuts. These studies lation per sq km in Lakshadweep is about 1951. have addressed several problems on the Androth with an area of 4.8 sq km has the largest enviornmental status ofLakshadweep in the recent population of9149 alldBitra (0.1 sqkm) has a resi past and a well founded data base is available. The dent population of226 (Data from Manorama Year present report is basically relying on earlier commu Book 1995, p. 680). Copra, Coir and Mass (dried nications by Pillai (1985, 1986, 1990, 1995); James tuna) are the mainstay of the economy, though a lot and Pillai (1989) and Pillai and Madan Mohan (1986). of foreign exchange is earned by sailors especially THE CHANGING FACE OF LAKSHADWEEP from Minicoy. Tourism is allowed on a limited scale The pristine nature of the atoll face seems to in some of the islands, but there seems to be vast have been altered to a great extent by human settle potential for ecotourism in several islands. ment, especially in the post-independence period. The typical atoll vegetation included, Pandanus, The surface soil was removed to make the land ar Moringa, Ficus, Artocarpus, Terminalia, able; subsurface sandstones were mined for con- 172 C.S'. GOPL\>1DfL4 PILL4I.t4VD FA. ITJOAfAS struction. Various construction activities coupled the last two decades. The lagoon is continuously with developmental programmes have changed the dredged in several islands. This has resulted i~ physiographic features of almost all atolls in the mass mortality of corals in KavaraUi, Minicoy and Lakshadweep. Virtually nothing exists in the pris Kiltau. A small fringing reef at the northern end oJ! tine condition. Introduction Jf exotic plants and Minicoy \-.-ith a luxllriant growth of corals (Nair and large scale destruction to natural vegetation has Pillai. 1972) is no more there. It is all buried under changed the phytal sociology. The ecological dis the sand dredged and dcposited over it. turbances and deficiencies of the Laksha-dweep A detailed survey of the lagoon by a team of were summarised by Wells (1988). scientists from CMFRI in 1988 was made to quanti The marine ecosystems -largely the lagoon habi tatively assess the percentage cover of living and tats and the shallO\v reef em,irons - in Lakshadweep dead corals in some of the morphozones of the valli have undergone drastic environmental deterioration ous islands, by transect and quadrat methods. due to many natural and anthropogenic parameters. Minicoy: To the environmentalists, it is difficult to convince The percentage coverage of living corals in some others, for want of critical baseline studies in the parts of Minicoy lagoon is only 5 to 10. In several pre-independence period. Except for Minicoy and plots 70 to 80% of the corals were dead due to vari- perhaps, the Kiltan atoll, any base line studies and 0us reasons. The corals of the southern part of the status reports of the habitats prior to the changes atoll have suffered mass mortality due to excessive are lacking. One has to rely on present state-of-art silting and all are buried. This large scale silting is to draw the conclusions, rather than to rely on de attributed to blasting of the reef flat at the northern ductions from comparison of the past and the tip pennitting greater influx of open ocean water into present. the lagoon. Since the southern reef flat is much THE COASTAL WNE raised the sediment is prevented from washing out Construction activities along the near-shore ar and thus gets accumulated killing all the corals. eas such as jetties (a necessary evil) and sea erosin Kavaratti: have caused an increase in the sediment load of the Dredging and other activities have effected large lagoon. Erosion is rampant at Minicoy, Chetlat and scale mortality of corals. The central part of the Amini. Filling up of the southern part of the lagoon lagoon has some growth of ramose corals but fifty in Minicoy is fast taking place as a result of sedi percent of the corals were dead. ment deposition. There is no major threat from any Kalpeni: heavy metal pollution. However, organic pollution Thenorthem half of the atoll has relatively richer as a result of human defecation and dumping of coverage and species diversity of corals than that human refuse is of a higher scale. No major facto of the southem half. Interference is minimum. The ries are functioning in Laksha-dweep, so also no percentage coverage of dead corals in the sample threat from thermal pollutants. Yet a major source plots varied from 20 to 25. of environmental damage is reUing of coconut husk in some parts of the lagoon. Observations have Amini: shown that there is a paucity of intertidal and The lagoon of Amini is very shallow with vast subtidal organisms at sites where retting of coco coverage of sea grass. The open windward reef flat nut husk was going on in Kiltan and Chetlat islands. has an extensive growth of Acropora thickets. The LAGOON coral growth in the lagoon is sparce. Kadmat: The marine biodiversity of most of islands is criti cally affected especially due to dredging. Dredging The Kadmat island has a vast lagoon with rich has both direct and indirect effect on fauna, espe growth of corals. However, dredged area had ma11)1 cially the sedentary forms such as corals, polycha dead shoals. The lagoon reef flat and outer reef etes and sponges. The reef flats of some of the have fairly rich live coral coverage. islands were blasted as in Minicoy to widen the Kiltan: channel to pennit the larger mechanised vessels in This island has suffered the worst environme11- F f!,NVIRONMENTAL DETERIORATiON iN LAA, ....' /L·W WEEP AND NEED FOR CONSERVATION .73 ontinuous!y tal damage in Lakshadweep. Almost all corals in the organisms. Death of ramose corals in the lagoon resulted in lagoon were found dead in 1988 consequent to certainly will affect the live bait population of small .1inico~ · and dredging and deepening the lagoon . fishes such 2S Pomacentrids and Apogonids (Pillai them end of Chetlat Island: and Madan Mohan, 1986). A typical example is the Is (Nair and This northern most atoll is the only one among dwindling population of Chromis caeru/es in the ,uried under the Lakshadweep islands that seems to have under southern half of Minicoy due to mass mortality of gone least environmental damage as a result ofhu corals (PiIIai, 1990). As already pointed by James et 'i a team of man intervention. The lagoon shoals were support aI, (1989) dead coral skeleton is vulnerable to Ie to quanti ing a rich and luxuriant growth of corals. The present bioeroding agents like sponges, molluscs and bor 'living and situation needs assessment. ing algae causing the breakdown of coral skeleton of the vari NATURAL FACTORS THAT AFFECT and their disintegration to coralline sand. This will ethods. result in faster filling oflagoon. Reefs subjected to ENVIRONMENTAL, CONSEQUENCES human activities all over the world seems to have Pests and predators in Lakshadweep were never rals in some lost their capacity to cgenerate in immediate future reported to be major causes for environmental dam (Wells, 1986).