PRIORITIZING MULTIPLE USES OF MANGROVES FOR ESTABLISHING ECONOMIC DEVELOPMENT POLICIES FOR THE MANGROVES OF SRI LANKA LEONARD PINTO Zoology Department, Open University of Sri Lanka (Paper presented at the special workshop for mangrove managers held in Phuket Island, Thailand in September 1986.) Summary The existing small area of mangroves in Sri Lanka is threatened as a result of population expansion and development. Aquaculture and land reclama- tion are major threats while extraction of molluscs and firewood adversely affect the ecosystem. Attempts are made to map and classify the mangrove ecosystem for multiple uses. Introduction The mangroves in Sri Lanka are discontinuously distributed along the coast, around lagoons, bays and estuaries covering an area between 6000 - 7000 ha. About 28 species of mangrove plants are found distributed forming a mixed vegetation. Mangroves in the dry zone occur together with saltmarshes. In such areas Avicennia marina is the dominant species. 1. The beneficiaries of the ecosystean The chief beneficiary of the mangrove ecosystem in Sri Lanka has been the coastal inhabitants, mainly the fishermen. Traditionally they have used the mangrove ecosystem for their day to day existence. It is unfortunate that the current situation in the north has inhibited the utilization of the mangrove resource by the fishermen of the north. It is only in recent years that large scale exploi- tation of mangroves, on commercial ventures such as aquaculture is taking place. 2. The extractible uses and their effect on mangroves The coastal inhabitants derive benefits from the mangroves. They use the mangrove wood for making poles, fishing gear, fishing crafts, and tannins. They extract prawns, crabs and fish from the mangrove waters. The export of crabs, prawns and ornamental fish is a thriving business. Some fishermen use the mangrove plants, especially Avicennia marina to make brush piles, a fishing method unique to Sri Lanka. However these operations seem to be less adverse on the ecosystem since the rate of extraction is not so rapid as to make a spectacular depletion of the resource or destruction of the ecosystem. 3. Extractible uses that are becoming a threat 3.1 Lime The removal of molluscan shells 'for calcium carbonate is increasing after the total ban of the coral mining. Removal of Telescopium telescopium, in truck loads to the kilns from the mangroves is taking place. Crnssostrea sp., Sacosstrea sp., Mere- trix casta and Geloina coaxans are also removed from the mangroves t o a lesser extent. 3.2 Firewood Although there is no special preference for mangrove firewood, the inhabitants living in the coastal areas find easy access t o mangrove forests and remove wood for kiln and bakery operations. 4. Operations that mutually exclude other activities .1 Aquaculture: Prawn culture is gaining grounds in Sri Lanka. Entrepreneurs are requesting for crown lands t o be developed for aquaculture. When such requests are made the sight is examined. If it is barren land (close t o a mangrove patch) or when it is in the salt marshes (near mangroves) permission is granted with certain restrictions on the area. Applicants are encouraged t o go into semi-intensive and intensive aquacul- ture but never extensive aquaculture. 4.2 Land reclamation Land reclamation of mangroves for building houses and hotels has taken place in some parts of Sri Lanka. Some of these activities would have been better planned after considering all the aspects of the mangrove land compared to other available land. 5. Some management strategies 5.1 Mapping Since the distribution of mangroves has been estimated roughly and that, a few decades ago, attempts are being made t o study and categorize the mangrove localities according t o their, quality. The new estimates show that the extent of mangroves much more than i t was thought t o be. Some areas have been mapped out by LANDSAT facilities with physical verification. Some areas have already been identified t o be set aside as reserves. 5.2 Integrated research programme Since information is scarce on the socio-economics, biology, hydrology and ecology of the mangroves of Sri Lanka, a project has been launched by NARESA to involve many universities and research institution in an integrated research programme. I t is expected that after one year of research, data collected would be useful to make better decisions and policies on the mangrove ecosystem in Sri Lanka. Already some of these projects have been completed. 5.3 Implementation of the law The forest ordinance prohibits the felling of trees in the mangrove as in other forests. The coastal area up to 300 m landwards and 2 km up the estuaries falls within the jurisdiction of the Coast Conservation Department. All activities that destroy the coastal habitat is forbidden. Yet implementa- tion of the law has been a problem. REFERENCES 1. ABEYWICKREMA B.A. (1960). Estuarine 5. PINTO L. 1980. Some uses of mangroves, vegetation of Ceylon. Proc. Abidjan Symp. Karmantha, May 23-25 on the humid tropics: 207-210 UNESCO. 2. AMARASINGHE M.D. and PERERA W.K.T. 6. SAMARAKOON J.I. and RAPHAEL Y.I. 1972). (1984). A, preliminary survey of peripheral On the availability of seed of culturable vegetation communities of Puttalam Lagoon shrimps in the Negombo Lagoon. In: Coastal and Dutch Bay. SLAAS 40 Ann. Sess. aquaculture in the Indo-Pacific region. Ed. (Abstract). TVR Pillay, Fishing news books, Surrey, pp. 251 -259 3. ARUCHELVAM K. 1968. The mangroves. The Ceylon Forester 8 (3 & 4) : 59--92 4. PINTO L. 1978. Some ecological aspects of 7. SENEVIRATNE E.W. 1979. The Sri Lanka selected mangrove islets in the Negombo Mangroves. Proc. UNESCO Seminar on Lagoon (Sri Lanka) M. Phil (Zoology) thesis. human uses of the mangrove environment and University of Sri Lanka, Colombo pp 116. management implications, Dacca. i SRI LANKA Jaffna Lagoon Kala Oya estuary- Portuguese Bay ambalagam Bay Mundal Lake Negambo i Bento ta i 5 Periya kalapu Pothuvil Arugam Bay Kiriga /la Bay Ma tara 0 15 30 45 60 Miles L I 1 I 1 SCALE VIDU 9_1_20.pdf VIDU 9_1_20 (2).pdf VIDU 9_1_20 (3).pdf VIDU 9_1_20 (4).pdf