Continuous access to clean water is becoming a major issue in the face of depleting water resources and growing demands. It is a serious environmental, health, social and economic problem as more than one-third of the world’s population face some form of water related issue, including depleting resources and degrading quality levels. Every year 1 billion people are affected by polluted water.
Sri Lanka, with its 65,610 km2 of surface area and 20.87 million people, is blessed with water bodies that cover around 4% of the land. Of these water bodies, a considerable portion is man-made. In Sri Lanka, there are more than 103 water basins, and a majority of these originate in the central hill region and the geography of the hill country consists of thousands of acres of tea plantations. In many instances, the feeder tributaries of these water bodies originate or flow within or in very close proximity to tea plantations. At present, the use of agrochemicals and other forms of anthropogenic activities within tea plantations can have major effects on flowing and standing water bodies in the hill country.
Believing that the sustainability of tea practices mainly depend on the health and wealth of the estate community, Dilmah is very concerned on the quality of water that is consumed by the estate community. With a view of establishing eco-friendly tea estates, Dilmah Conservation provided support to the Department of Zoology, University of Colombo to conduct a research on the quality of water and the diversity of freshwater insects inhabiting water bodies in Dilmah’s tea estates, as aquatic insects are well established as indicators of water quality and are used as such the world over.
Apart from being important components of aquatic systems, insects form the largest unknown component of Sri Lanka’s exceptionally high biodiversity. Sri Lankan aquatic insects are generally a neglected group, with the exception of basic research work carried out by overseas based researchers. This research has been collated into a few publications but a majority of aquatic insect collections from Sri Lanka are deposited in museums and repositories overseas, inaccessible to most local researchers. This situation is the result of unrestricted access, and removal of Sri Lankan species by overseas researchers, due to loopholes in the law. With the enforcement of the laws to protect the fauna and flora in the country, this situation has been somewhat curtailed.
The overall objective of this initiative is to transform Dilmah’s tea estates into becoming more ecologically friendly and work towards the maintenance of biodiversity within them. The initiative also aims to promote the practice of sustainable development within its plantations and companies engaged in tea, rubber and minor crops.
Research work commenced in 2011 and it was the first step in analysing a tool for measuring and predicting freshwater quality using aquatic insects. This piece of work also fit into long term academic research and teaching programme on Ecotoxicology that the Department of Zoology, University of Colombo launched in 2012 with the support of the World Bank and Government of Sri Lanka funded, Higher Education for the 21st Century (HETC) Project.
This study so far has sampled water bodies of Dilmah owned estates from each of the elevations that is normally used to categorize tea growing areas. Namely Endana, Houpe and Rilhena estates from low country (below 600 m msl), Westhall, Craighead and Galamuduna estates from mid country (between 600-1200 m msl) and Queensberry and Kataboola estates from up county (above 1,200 m msl). In order to make comparisons between tea estates and natural spring water, water from bodies that originate and flow through hill ranges adjacent to tea estates were sampled while permission to collect samples of insects was obtained from the Department of Wildlife Conservation.
The study focused on measuring the impact of human activities on physicochemical parameters of water on associated lands. After establishing the baseline of information on freshwater insect diversity, abundance and water quality, the next step was to screen prospective candidate species for use as indicators.
According to the results obtained up to date, almost all the sampled water bodies in Dilmah tea estates had good quality water for most of the parameters which define drinking water quality according to WHO guidelines. We have identified new sources of water which can be used for drinking purposes by the estate community. Work is in progress to identify the species of insects collected so far and to screen candidate species.
The ultimate goal of this project is to build an indicator to measure water quality of any freshwater water body in Sri Lanka only using the aquatic insect index and without the use of chemical tests.
Dilmah Conservation is working with the University of Colombo to carry out this fundamental scientific research that has both short and long term implications for Sri Lanka’s future development and contributing to scientific advancement.