Modelling of energy transformations in fertilized tropical fish ponds
The energy budget patterns of three tropical ecosystems in which the polyculture of fish was practised were studied. The rates of organic production of the three tropical ponds over two annual cycles were evaluated. Study of the utilization of energy in the three ponds, which were fertilized with vermicompost, cow dung and diammonium phosphate, revealed that herbivores were more efficient in utilizing energy than were autotrophs. The available energy in these systems was supplied by autochthonous sources. Silver carp was found to be the most efficient organism in converting energy in the grazer food chain in the ponds. The efficiency of the system in regard to fish production was 0.052, 0.049, and 0.051%, respectively, of the total available solar radiation. Organisms in various trophic levels were all characterized by energy changes in the studied ponds, forming the food webs contained in them.