Ecosystems in Sirinthorn and Nam Ngum Reservoirs; A comparison

Abstract

Trophic models were constructed for Sirinthorn Reservoir (Thailand) and Nam Ngum Reservoir (Lao PDR), using ECOPATH software to understand their ecosystems. The models reveal that the trophic structure of the reservoirs is similar. Results show that the ecosystems in both lakes are sustained and considered as productive reservoirs. The transfer efficiency is between 10 and 15% at all levels, indicating an intact food web. In both reservoirs, total fish productions can support fishing activities. There aer also presented the (1) energy flow in each trophic level, (2) mixed trophic impact, in term of predator-prey relationship and fishery and (3) calculate the net biomass and production of the groups of organisms. The fishery operates at a trophic level around three, meaning that mainly zoophagous fishes are targeted.