1 Towards improved management of living aquatic resources in watersheds of the Dry Zone, Sri Lanka

Livelihoods in the Dry Zone of Sri Lanka have traditionally revolved around paddy cultivation under village tanks. In recent times water-use strategies have responded to a range of demographic and environmental pressures. This has implications for the sustainable management of natural resources, especially living aquatic organisms. The impacts of such change need to be understood at the level of the watershed rather than for individual communities and tanks, the current focus of most dry-land development in Sri Lanka. Watersheds of Northwest Province are highly complex. Understanding requires a holistic approach, which considers hydrological, biological, social and economic factors. In addition to the well-recognised constraint of seasonal water availability, a range of resource flows which move in both upstream and downstream directions, are critical in determining levels of aquatic productivity. Many of these flows depend on seasonal spill events that link successive tanks within cascading systems. This includes migration routes, which permit the natural recruitment of fish stocks