Abstract:
INCO-DC FISHSTRAT Project, funded by the European Commission, is an ongoing multidisciplinary
research program undertaken over the period 1998?2001. Three reservoirs in Sri
Lanka (Victoria, Minneriya and Udawalawe) of different morphology, age and geographic
location, Ubolratana reservoir, in Thailand, and Lake Taal, in the Philippines, are the object of this
study. The scope of the project encompasses a comparison of the limnology, fisheries and socioeconomic
aspects of local communities in order to determine whether the trophic characteristics
and key ecosystem processes sustain the available fisheries, and to examine the ecological
potential for increased fish production by intensive cage culture. The paper first presents integrated
results on trophic state, trophic structure and food web relationships of different water bodies. The
results demonstrate the importance of ecosystem-orientated analysis in order to optimise management
strategies. The broad spectrum of Asian water bodies studied allows testing of a set of
hypotheses on: 1) the control of the trophic state of lakes and reservoirs by geographic, climatic
and morphometric conditions; 2) the significance of the structure of the fish assemblages (biogeography,
exotic species) on ecosystem processes; 3) bottom up versus top down control under
Asian reservoir and lake conditions (in comparison to established concepts for water bodies in the
temperate zone); and 4) the human impact and resilience of ecosystem processes and trophic
conditions towards human impact.