The application of Ecopath to seven African lakes, four other lakes and two rivers - including two systems (Lake George and the River Thames), previously studied by the International Biological Programme -- has amply demonstrated the applicability of Ecopath to freshwater bodies, whether tropical or temperate, exploited or not, and the comparability of the results obtained from these application with the results obtained from marine systems (see contributions in Christensen and Pauly 1993).
That Ecopath also turned out to be suitable for description of culture systems was a pleasant surprise. The first batch of such applications was confined to ecosystems including at least some aquatic components, i.e., a southern Chinese silkworm - fish integrated system, a Philippine rice-cum-fish system, and a tilapia - elephant grass system among others. Another batch emerged from the work of J.P. Dalsgaard (formerly with ICLARM), who used Ecopath to describe and compare the performance of farming systems, of which some may include fish ponds, but many are entirely terrestrial.
The developments will demonstrate whether - as we believe - Ecopath type approaches may become in the next years a general tool, unifying fields as disparate as fisheries science, limnology, aquaculture, and farming systems research.
We welcome cooperation with colleagues interested in modeling freshwater bodies using Ecopath -- do contact us.