Villorita Cyprinoides) Fisheries in Wetland
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© Society for Promotion of Tropical Biodiversity, Jabalpur IDENTIFICATION AND EVALUATION OF ECOSYSTEM SERVICES PROVIDED BY CLAM (VILLORITA CYPRINOIDES) FISHERIES IN WETLAND THANKAM THERESA PAUL*, SHYAM S SALIM, V.S. MANOHARAN AND USHA UNNITHAN Central Inland Fisheries Research Institute, CMFRI Campus, Kochi - 682024, Kerala, India *Corresponding author: [email protected] ABSTRACT: Black clam (Villorita cyprinoides), constitute a major molluscan based subsistence level fishery in Vembanadlake providing a variety of ecosystem services to the dependent populations of the ecosystem. The non- realization of the values of the services provided by clams coupled with the anthropogenic activities like dredging aggravated the non-sustainable harvest of the resource. The paper attempts to evaluate the provisioning and cultural services provided by clams in-order to highlight the importance of the management of this ecosystem service provider and various tradeoffs between anthropogenic activities and clam resource utilizations. Keywords: Black clam management, ecosystem service provider, ecosystem service evaluation, Citation: Paul TT, Salim SS, Manoharan VS, Unnithan U (2015) Identification and evaluation of ecosystem services provided by clam (Villorita cyprinoides) fisheries in wetland. Indian J Trop Biodiv 23(1): 21-29 Received on : 24 Apr. 2015 As per the Ramsar several species of aquatic life (Kurupet al, 1990). The Accepted on : 11 May. 2015 Convention definition, major species supporting the fisheries include the most of the natural water molluscan bivalve, Villoritacyprinoides (Black clam)and bodies (such as rivers, lakes, coastal lagoons, Etroplussuratensis (Pearl spot). The lake contributesto mangroves, peat land, coral reefs) and manmade nearly 99 per cent of total Villorita harvest (56700t). The wetlands (such as ponds, farm ponds, irrigated fields, collection and sales of the harvested clams is organized sacred groves, salt pans, reservoirs, gravel pits, sewage via co-operative societies formed of clam collectors farms and canals) constitute the wetland ecosystem in residing in the clam-fishery based villages distributed India (Bassi etal, 2010). Globally, the areal extent of across Alapuzha and Kottayam districts of Kerala. wetland ecosystems ranges from 917 million hectares Nearly 75% of the total harvest is contributed by (m ha) to more than 1275 m ha (Bassi et al, 2014). As Muhamma and Vechoor clam shell cooperative per the estimates, India has about 7.57 lakh wetlands societies located in Alapuzha district of kerala. with a total wetland area of 15.3 m ha, accounting for The anthropogenic activities affected the nearly 4.7 per cent of the total geographical area of the phytoplankton production upon which Villoritasp country (SAC, 2011). Vembanadlake in Kerala is one (suspension feeders) are wholly dependent. The value among the 26 wetlands designated as Ramsar of the services provided by clam fisheries are not sites(Ramsar, 2013). Vembanadlake, a backwater, realized and quantified to the fullest extent yet, which formed by the backward flow of seawater due to an acts as limiting factors highlighting the aspects of obstruction in the natural current, is a unique ecosystem conservation and sustainable harvest of the species. found in Kerala. Vembanad Lake, the largest backwater And hence, we are in an attempt to destroy the resource in Kerala, and second largest brackish water lake in knowingly or unknowingly by our activities. Any service, India covering an area of 2033 sq. km is renowned as a when expressed in monetary or quantifiable terms will major contributor to inland fisheries. The designation of emphasize its evaluationmore rationally taking into this wetland system as a Ramsar site in 2002 calls for the account the socioeconomic costs and benefit aspects. immediate conservation of the ecosystem from the Identifying the lacunae, Millennium ecosystem major threats like urbanization, population growth, assessment (2005) emphasized that the various pollution, tourism, dredging etc as well as sustainable services provided by the ecosystem benefitting human utilization of its resources. population needs to be identified and evaluated for Vembanad Lake, an ecotone between brackish judicious utilization of the resources. water and freshwater environment, is an abode of MEA (2005) which propounded the concept of the aquatic biodiversity. The soft organically rich evaluation of ecosystem services asserts the need for sedimentary substratum of the inshore region is an ideal the identification of ecosystem service providers (ESP) habitat for shrimps. Vembanad serves as a habitat for a as the preliminary step in the evaluation process. This variety of fin fishesand shell fishes, and a nursery for study identifies clams as ESPs and focusses on the (21) Colour Page Indian Journal of Tropical Biodiversity, 23(1) 2015 identification and economic evaluation of various provision for festival allowance, floating insurance services provided by the clam fishery to the human schemes etc. Almost four to five clam fishing villages settlement. The objectives are to develop a conceptual come under the jurisdiction of each society (Suja and framework encompassing the different ecosystem Mohamed, 2011).Ten key informants have been services provided by the clam resources, estimating the identified from each co-operative society. A socio- values of selected ecosystem services using economic survey was conducted to identify and appropriate proxies, analyze the tradeoffs between evaluate the various services provided by the clam anthropogenic activities like dredging vis-a-vis clam population to the human settlement in the area post a resources utilizations. reconnaissance study. The survey schedule included MATERIALS AND METHODS various details encompassing socio-economic status, livelihoods, outlets of clam shell utilization and choice The study is conducted with the cooperation of seven experiments on impact on dredging using key driver black clam cooperative societies namely Aaryad, indicators etc. The sampling areas have been Muhamma, Vaikkom, Vechoor,Thycattussery, Kavalam represented in the Fig 1. The clam production data for and Kuthiathode .These co-operative societies located the quinquennial period from 2009-2014 were collected in Kottayam and Alappuzha districts are involved in the from the respective cooperative societies to arrive at implementation of multitude of welfare schemes, clam production estimates and its utilisation. Fig1: Location of lime shell cooperative societies RESULTS AND DISCUSSION which the linking or the supporting services form the Development of a conceptual framework basis for the three other MEA (2005) defines the services provided by the s e r v i c e s . A c o n c e p t u a l ecosystems which benefitted humans directly and framework of the services provided by clamsis provided indirectly as ecosystem services. The concept of in Fig 2. ecosystem services helps to express the usefulness of Conceptual framework of the ecosystem services biodiversity in a region to the wellbeing of human population who are solely dependent on the ecosystem The clams are providers of various ecosystem services, for various needs. The ecosystem services are which are broadly classified under four categories as categorized into four viz., linking, provisioning, cultural provisioning services, regulating services, linking or and regulating services (MEA 2005, TEEB 2010b), of supporting services and cultural services. The services (22) Indian Journal of Tropical Biodiversity, 23(1) 2015 that are provided by (clams) benefactors are mainly quantitative terms and throws light upon the fact that provisioning services. The various services provided by since clams are a good source of many micro elements clams vary with the necessities of the society. and macro elements, the very consumption of clams in prescribed doses would be adequate to overcome various health related issues. Minerals Fossil deposits from Vembanadlake are the major contributors of raw materials for cement manufacture by Travancore Cements Limited, a government undertaking. When low magnesia content in the fossil deposits used for cement manufacture ensures brilliant whiteness and durability, the light fast pigments ensure color retention. These qualities affirm demand for the particular cement sourced out from fossil beds. Ravindranet al (2006) has also detailed the quality of white cement made out of lime shell as highly durable and of superior quality. The clam shells are also used in Fig 2: Conceptual framework of ecosystem services of clams titanium producing company as a source of calcium Provisioning services carbonate. Locally lime shell is heated and powdered to produce lime which is used in agriculture. It is also used The provisioning services are those ecosystem as a cost effective substitute for gravel in the concrete services that describe the material or energy outputs mix at a rate double that is required of gravel. Though from the ecosystem (MEA, 2005). The ecosystem this is an indigenously developed technology, it was service provider (clams) act as sources for a multitude primarily used to sell out the un utilized clam shells. It is of natural as well as metamorphosed resources in the also used in tanning industry, bleaching of sugar, and form of food, minerals, feed, seed, genetic and carbide industry and as a constituent for newspaper ornamental resources, thus performing the provisioning manufacturing industry. services of the ecosystem