The Lakshadweep Archipelago is located on the Laccadive - Chagos ridge, believed to be the submarine extension of the Aravalli mountains. The various atolls rise from a depth ranging from 1500 to 4000 m. The Lakshadweep Archipelago consists of 12 atolls, 3 reefs and 5 submerged banks, all of coral formations. The total land area is about 32 sq km. The height of islands vary from 1 to 1.4 m from MSL

Pillai, C S G

Thomas, P A

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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 The Lakshadweep Archipelago is located on the Laccadive - Chagos ridge, believed to be the sub-marine extension of the Aravalli mountains. The various atolls rise from a depth ranging from 1500 to 4000 m. The Lakshadweep Archipelago consists of 12 atolls, 3 reefs and 5 submerged banks, all of coral formations. The total land area is about 32 sq km. The height of islands vary from 1 to 1.4 m from MSL. Except Amini all islands have a shallow la-goon. The windward side is with rubble shores while the lagoon leeward side is with a sandy shore. The reef flats are mostly fossilised with algal ridges and believed to have been shaped in the Holocene period. The climate is warm and humid. The Archi-pelago is exposed to both NE and SW monsoons and the average annual rain fall is about 1640 mm (Data based on Minicoy, the southern-most atoll). The atolls are located in the cyclonic belt and often severe storms are experienced. Ten of the atolls are inhabitated and the area of inhabitated islands alto-gether is about 26.2 sq km. A recent estimate by remote sensing (Shai, 1994) has shown that the ex-tent of reef area in Lakshadweep is 140.1 sq km. The total population in lakshadweep according to the latest census is 51 ,681 . The average density of popu-lation per sq km in Lakshadweep is about 1951. Androth with an area of 4.8 sq km has the largest population of9149 alldBitra (0.1 sqkm) has a resi-dent population of226 (Data from Manorama Year Book 1995, p. 680). Copra, Coir and Mass (dried tuna) are the mainstay of the economy, though a lot of foreign exchange is earned by sailors especially from Minicoy. Tourism is allowed on a limited scale in some of the islands, but there seems to be vast potential for ecotourism in several islands. The typical atoll vegetation included, Pandanus, Moringa, Ficus, Artocarpus, Terminalia, Calophyllum inophyllum and Thespesia. The ground vegetation is seasonaL Casuarina is intro-duced. Coconut plantation, fringes the sandy shores and the interior of the islands. In recent past many garden plants and vegetables are intro-duced into the atoll . Destruction to the natural veg-etation consequent to agricultural activities was sig-nificant. Grazing pressure from the introduced cattle and goats is also causing destruction to vegeta-tion. Mangroves are scarce, except at some pock-ets in Minicoy. RESUME OF MARINE RESEARCH IN LAKSHADWEEP Early investigations on the marine habitats and reefs of Lakshadweep were those of Alcock (1902) and Stanley Gardiner (1903-06). During the post-independence period, scientists ofthe C.M.F.R. In-stitute, Kochi and N.LO., Goa carried out a series of impressive studies on the living resources of Lakshadweep as well as the human and natural im-pact on the ecosystems. Detailed accounts of these studies are provided by James, 1989 and James et al., 1986 and Bakus, 1994. On the agricultural sector, Central Plantation Crops Research Institute (lCAR) is doing a lot of research, especially on coconuts. These studies have addressed several problems on the enviornmental status ofLakshadweep in the recent past and a well founded data base is available. The present report is basically relying on earlier commu-nications by Pillai (1985, 1986, 1990, 1995); James and Pillai (1989) and Pillai and Madan Mohan (1986). THE CHANGING FACE OF LAKSHADWEEP The pristine nature of the atoll face seems to have been altered to a great extent by human settle-ment, especially in the post-independence period. The surface soil was removed to make the land ar-able; subsurface sandstones were mined for con-172 struction. Various construction activities coupled with developmental programmes have changed the physiographic features of almost all atolls in the Lakshadweep. Virtually nothing exists in the pris-tine condition. Introduction Jf exotic plants and large scale destruction to natural vegetation has changed the phytal sociology. The ecological dis-turbances and deficiencies of the Laksha-dweep were summarised by Wells (1988). The marine ecosystems -largely the lagoon habi-tats and the shallO\v reef em,irons - in Lakshadweep have undergone drastic environmental deterioration due to many natural and anthropogenic parameters. To the environmentalists, it is difficult to convince others, for want of critical baseline studies in the pre-independence period. Except for Minicoy and perhaps, the Kiltan atoll, any base line studies and status reports of the habitats prior to the changes are lacking. One has to rely on present state-of-art to draw the conclusions, rather than to rely on de-ductions from comparison of the past and the present. THE COASTAL WNE Construction activities along the near-shore ar-eas such as jetties (a necessary evil) and sea erosin have caused an increase in the sediment load of the lagoon. Erosion is rampant at Minicoy, Chetlat and Amini. Filling up of the southern part of the lagoon in Minicoy is fast taking place as a result of sedi-ment deposition. There is no major threat from any heavy metal pollution. However, organic pollution as a result of human defecation and dumping of human refuse is of a higher scale. No major facto-ries are functioning in Laksha-dweep, so also no threat from thermal pollutants. Yet a major source of environmental damage is reUing of coconut husk in some parts of the lagoon. Observations have shown that there is a paucity of intertidal and subtidal organisms at sites where retting of coco-nut husk was going on in Kiltan and Chetlat islands. LAGOON The marine biodiversity of most of islands is criti-cally affected especially due to dredging. Dredging has both direct and indirect effect on fauna, espe-cially the sedentary forms such as corals, polycha-etes and sponges. The reef flats of some of the islands were blasted as in Minicoy to widen the channel to pennit the larger mechanised vessels in C.S'. GOPL\>1DfL4 PILL4I.t4VD FA. ITJOAfAS the last two decades. The lagoon is continuously dredged in several islands. This has resulted i~ mass mortality of corals in KavaraUi, Minicoy and Kiltau . A small fringing reef at the northern end oJ! Minicoy \-.-ith a luxllriant growth of corals (Nair and Pillai. 1972) is no more there. It is all buried under the sand dredged and dcposited over it. A detailed survey of the lagoon by a team of scientists from CMFRI in 1988 was made to quanti-tatively assess the percentage cover of living and dead corals in some of the morphozones of the valli-ous islands, by transect and quadrat methods. Minicoy: The percentage coverage of living corals in some parts of Minicoy lagoon is only 5 to 10. In several plots 70 to 80% of the corals were dead due to vari-0us reasons. The corals of the southern part of the atoll have suffered mass mortality due to excessive silting and all are buried. This large scale silting is attributed to blasting of the reef flat at the northern tip pennitting greater influx of open ocean water into the lagoon. Since the southern reef flat is much raised the sediment is prevented from washing out and thus gets accumulated killing all the corals. Kavaratti: Dredging and other activities have effected large scale mortality of corals. The central part of the lagoon has some growth of ramose corals but fifty percent of the corals were dead. Kalpeni: Thenorthem half of the atoll has relatively richer coverage and species diversity of corals than that of the southem half. Interference is minimum. The percentage coverage of dead corals in the sample plots varied from 20 to 25. Amini: The lagoon of Amini is very shallow with vast coverage of sea grass. The open windward reef flat has an extensive growth of Acropora thickets. The coral growth in the lagoon is sparce. Kadmat: The Kadmat island has a vast lagoon with rich growth of corals. However, dredged area had ma11)1 dead shoals. The lagoon reef flat and outer reef have fairly rich live coral coverage. Kiltan: This island has suffered the worst environme11-ontinuous!y resulted in .1inico~· and them end of Is (Nair and ,uried under 'i a team of Ie to quanti-'living and of the vari-ethods. rals in some In several due to vari-I part of the o excessive Je silting is :le northern 11 water i lito at is much iashing out ~ corals. rected large part of the lIs but fifty ively richer s than that mum. The the sample v with vast rd reef flat ckets. The 1 with rich I had many outer reef vironmen-F f!,NVIRONMENTAL DETERIORATiON iN LAA, .... '/L· W WEEP AND NEED FOR CONSERVATION .73 tal damage in Lakshadweep. Almost all corals in the lagoon were found dead in 1988 consequent to dredging and deepening the lagoon . Chetlat Island: This northern most atoll is the only one among the Lakshadweep islands that seems to have under-gone least environmental damage as a result ofhu-man intervention. The lagoon shoals were support-ing a rich and luxuriant growth of corals. The present situation needs assessment. NATURAL FACTORS THAT AFFECT ENVIRONMENTAL, CONSEQUENCES Pests and predators in Lakshadweep were never reported to be major causes for environmental dam-age. Though Acanthaster planci, the crown of thorns was reported from some islands, their num-bers were never in excess of natural stage to cause any mortality to corals. Recently a suspected case of White Band disease was reported from Kavaratti (Pillai, unpub.) causing mortality to ramose corals. The occurrence of this pathologic condition in other atolls is not hitherto investigated. EXPLOITATION PRESSURE The exploitation of various living resources from the lagoon and shallow reefs of Lakshadweep is of a higher order. Till date no reliable estimate of the resource availability is made to suggest any pattern of sustainable resource utilisation. The status of many economically important species are yet to be ascertained. Shell and finfishes are the major re-sources that are exploited. Shell collection espe-cially from the reefs is of high order and many spe-cies of gastropods such as Cyprea spp. are cer-tainly dwindling. The post-independence period has certainly made a fillip in pole and line tuna fishery due to the introduction of mechanised vessels. The capture of Jive baits from the lagoon of Minicoy and Kadmat has registered manifold increase to satisfY the higher demands. The traditional conser-vation methods practiced by the Minicoy people in the earlier days arc not followed strictly. CONSEQUENCES OF ENVIRONMENTAL DAJ\'lAGJ; The atolls of Lakshadweep, as elsewhere, are of COLli Ilrgin. Many of the marine living resources a;l; I ·d · associated. Destruction to reefs directly caU~l'S the shrinkage of living habitat to associated organisms. Death of ramose corals in the lagoon certainly will affect the live bait population of small fishes such 2S Pomacentrids and Apogonids (Pillai and Madan Mohan, 1986). A typical example is the dwindling population of Chromis caeru/es in the southern half of Minicoy due to mass mortality of corals (PiIIai, 1990). As already pointed by James et aI, (1989) dead coral skeleton is vulnerable to bioeroding agents like sponges, molluscs and bor-ing algae causing the breakdown of coral skeleton and their disintegration to coralline sand. This will result in faster filling oflagoon. Reefs subjected to human activities all over the world seems to have lost their capacity to cgenerate in immediate future (Wells, 1986). As pointed out by Pillai (1975) reef formation in places where destruction was near to-tal is a remote possibility for decades to come, though some coral growth may take place if the sub-stratum is suitable for recolonisation. CONSERVATION OF THE ATOLLS The corals and coral associated living fawla and flora in the atolls form the major component of ma-rine biodiversity. As already pointed out by Pillai (1985, 1990) the reef environs and the associated fauna in Lakshadweep is fast deteriorating due to both anthropogenic and natural causes. The reef resources form a major live supporting source for the islanders in many respects and it is imperative that these valuable resources should be utilised in a sustainable way and conservation strategies should be adopted on a priority basis. The user -conservationist conflict is likely to be a major hin-derance in this regard. As far as possible develop-ment and conservation should go hand in hand. Dredging operations in the lagoon and blasting of the reefs for navigational purpose should be to the minimum if not possible to dispense with altogether. ExperieJlrf.. has shown that dredging once done has to be repeatedly done for the sediment supply from outer reefs is getti.ng enhanced. Similarly blasting of the reefs enhances sea erosion as is seen in some sites. Exploitation of the resources needs careful monitoring. It is advisable to mark certain core zonef in all islands as fully protected, without any human interference so that a breading stock is kept main-tained. In all matters of conservation the opinion of the tribal community may be sought and their full co-operation listed. Suggestions have been made 174 in the past (James and Pillai, 1989) on the declara-tion of marine parks in Lakshadweep. If the entire island cannot be declared as a protected area due to social and economic reasons, some sites in each island should be notified as reserves or parks. On c.s. GOPINADHA PILLAI AND PA. THOMAS the land side application offertilisers and pesticides for agricultural operations needs careful watching. At any event this paradise of ours needs immediate attention on the point of nature conservation. REFERENCES ALcock, A., 1902: A natllralist in Indian seas. John Murray, London, 328 pp. BAKus, J. GERALD, 1994: Coral reef Ecosystems. Oxford & IBH pub. New Delhi, 232 pp. GARDINER, J.S., 1903-1906: The fallna and geography of Maldive and Laccadive Archipelagoes. VOL I and II. Cambridge Univ. Press. JAMES, P.S.B.R., 1989: History of marine research in Laksha-dweep. Blill. Cent. Mar. Fish. Res. Inst., 43: 9-25. ' JAMES, P.S.B.R. AND C.S.G, PILLAl, 1989: Suggelotions for es-tablishing a national Marine Park in Lakshadweep. Ibid., 248-252. JAMES, P.S,B.R. et al. 1986: Marine fisheries research in Laksha-dweep. A historical resume. Mar. Fish. Infor. Serv, T&E Ser., 68: 7-9. NAIR, P.V.R. AND C.S.G. PILLAI 1972: Primary productivity of some coral reefs in the Indian seas. Proc. Symp. Corals and coral reefs. India (Eds. C. Mukundan and C.S.G. Pillai): 33-42. PILLAI, C.S.G., 1975: An assessment of the effects of envi-ronment and human interferences on the coral reefs of Palk Bay and G. Mannar along the Indian coast. Seafood Export J. 7(12): \-13. PILLAl, C.S.G., 1985: Ecological crisis in coastal and marine habitat. In: India's environment - CriSis and Re-sponse. Natraj pub., New Delhi: 120.130. PILLAl, C.S.G., 1990: The endangered marine and terrestrial habitats in Minicoy Atoll - Lakshadweep Proc. Semi-nar Conserv. developing cOllntries. BNH (1983) : 267-279. PILLAI, C.S.G., 1986: Status of coral reefs in Lakshadweep. Mar. Fish. InfO!: Servo T&E Ser., 68: 38-41. PILLAI, C.S,G, AND MADAN MOHAN, 1986: Ecological stress in Minicoy lagoon and its impact on tuna live-baits. Ibid., 68: 33-37, PILLAl, C.S.G., 1995: Coral reefs of India - their conserva-tion and management. In: Marine Biodiversity their conservation and management, (Eds. N.G. Menon and C.S,G. Pillai), CMFR Institute, Kochi: 16-31. SIIAI, BALDEVI, 1994: Report to Ministry of Forest and En-vironment, Unpublished. WELLS, M. SUESAN, 1986: A future for coral reefs. New Scientist 1532: 1-5. WELLS, M. SUESAN, 1988: Coral reefs of the world. Vol. 2. India, IUCN: 79-94. 

Environmental deterioration in Lakshadweep and need for conservation of living resources

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Environmental deterioration in Lakshadweep and need for conservation of living resources

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