RESEARCH ARTICLE

AN ASSESSMENT OF WATER RESOURCES DEPENDENCY OF SURROUNDING COMMUNITY, IMPACTS OF AQUATIC WEEDS AND EFFECTIVE WEED CONTROL METHODS OF THE WATER BODIES IN ANAWILUNDAWA WILDLIFE SANCTUARY AND RAMSAR WETLAND IN SRI LANKA

Abstract

The Anawilundawa Wildlife Sanctuary (AWS) was established in June 1997 by the Department of Wildlife Conservation (DWC), Sri Lanka under the provisions of the FFPO. (Government Gazette number 97915 of 11 June 1997) Considering its biodiversity and Wetland values, the sanctuary was recognized as a wetland of International Importance by the Ramsar convention in 2002.

The AWS consists of a group of seven shallow cascading reservoirs including the around terrestrial landmass. The reservoirs are the heart of the sanctuary which depends on the balance of the wetland ecosystem. The people in and around, depend on the water resource of the sanctuary for their livelihoods. Therefore the reservoirs play a significant role for the balance of the wetland ecosystem as well as the dependencies of the surrounding community. But the reservoirs are covered with aquatic weeds.

The objective of the present study is to access the impacts of the weeds and to propose management practices to control the aquatic weeds. The direct observations, interviewing the community, and several pilot practices had been conducted during the study.

The results reviles that, there is a seasonal pattern of water resource dependency in the study area. The extraction of non timber forest products takes place throughout the year. The water level of the sanctuary indicates a positive relationship with the water resources dependencies. There are about ten aquatic weeds in the AWS. The most impacts cause from Water hyacinth (Eichhornia crassipes), Salvinia (Salvinia molesta), and Water lettuce (Pistia stratootes). The large leaf area of weeds leads to increased water loss through transpiration. It interfere with fish life by reducing oxygen level in water, producing toxic substances such as Hydrogen Sulphide and reducing phytoplankton population, prime food sources for fish. Weeds reduce the water flow and increase the siltation. When compared with the previous records, in the full capacity condition, the water capacity of the reservoirs are eight inches lower than that of 1995. Water hyacinth also downgrades recreational water facilities by reducing the water surface, creating offensive odors and tainting of water.

Mechanical control of weeds is one method, and removal of Salvinia by hand or machine is a practical control method. Biological control of Salvinia and Water hyacinth is a better method in this sanctuary as this is a protected area. In 1990, Agriculture Department of Sri Lanka has introduced Salvinia weevil to these water bodies. The DWC, the management authority of the sanctuary, organized a campaign for the removal of aquatic weeds May, 2005 during the peak drought. Surrounding community involved with this activity through their CBO. Prevention is the best form of weed control. The community can also help to prevent the spread of aquatic weeds by reporting the Department of Wildlife Conservation. Rehabilitation of water outlets of the reservoirs should be done immediately. Desilting of the water bodies is another important practice to increase the water capacity. Community participation for weed control, desiltation of the reservoirs, to control the illegal activities affecting the balance of the ecosystem of this study area could be suggested as some immediate site specific actions with appropriate strategies.

Keywords: Water Resource, Community, Aquatic Weeds, Anawilundawa, Sanctuary, Ramsar, Wetland

How to Cite: Wilson,S. C, (2006). AN ASSESSMENT OF WATER RESOURCES DEPENDENCY OF SURROUNDING COMMUNITY, IMPACTS OF AQUATIC WEEDS AND EFFECTIVE WEED CONTROL METHODS OF THE WATER BODIES IN ANAWILUNDAWA WILDLIFE SANCTUARY AND RAMSAR WETLAND IN SRI LANKA.WILDLANKA, 1(1):Pages 175-184

Published On:2006-01-01

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