The Godavari deltaic system in Andhra Pradesh, India, is still covered by extensive mangrove forest and sustains important economic activities related mainly with rice farming, fishing and rapidly extending aquaculture. Mangal in Sri Lanka is confined to estuaries and to lagoons and may be considered species-rich and structurally diverse. Different climate regimes as well as topographical and hydrodynamic factors are thought to be at the basis of various mangrove types. While it is obvious that many human activities in these regions of India and Sri Lanka such as fisheries, wood extraction, aquaculture rely on the presence of mangrove forest, the intrinsic interrelationship between natural occurrence and productivity of specific crustacean, shellfish and finfish communities on the one hand and mangroves on the other is but poorly known. This is a paradox, since deleterious effects of human activities on the normal functioning of a mangrove ecosystem on which they are apparently dependent compromises sustainability. A will to protect and manage the mangrove forests can clearly be discerned. This is however not matched by our understanding of factors governing their establishment, dynamics and regeneration, which impedes rational management plans. The work focusses on the following points: Spatial variability of aquatic flora and fauna as a function of freshwater flow Modelling of freshwater flow Spatial variability of the aquatic flora and fauna Spatio-temporal dynamics of flora and vegetation Present day spatial structure of the mangrove area. Temporal dynamics. Ground truth data validate observation from aerial photographs. Overlaying of the vegetation analysis from the time series to detect temporal trends in vegetational changes, if present, is greatly facilitated by ARC/Info GIS and made available to other teams under ARC/View format. Functional linkages between aquatic fauna (fish and shellfish) and mangroves: trophic interactions and role of refuge Nutritional dependency of larvae on mangrove litter Stomach content of selected species of macrobenthos Food sources for different fish species and for different life stages of fish species. Investigation of fish diurnal migratory patterns Mangrove prop roots as shelter for fishes Evaluation of capture fishery production by mangrove forest Prawn farming and impact