ECOSYSTEM MODELING OF A MULTISPECIES INTEGRATED AQUACULTURE POND IN SOUTH CHINA

A model of an integrated aquaculture pond in Suzhou, China, was developed with phytoplankton, zooplankton, dissolved oxygen, phosphorus, silicon, detritus, sediment, and six species of fish: black carp (Mylopharyngodon piceus), common carp (Cyprinus carpio), Wuchang fish (Megalobrama amblycephala), silver carp (Hypophthalmichtys molitrix), grass carp (Ctenopharyngodon idella) and bighead carp (Aristichthys nobilis). All biological state variables were treated as concentration with energy units (kJ m-2). The model replicated observed changes in primary productivity, dissolved oxygen, and fish production using energy flow data collected from a black carp-common carp pond in China. Simulation results and sensitivity analysis suggested that through multiple feedback mechanisms, the pond ecosystem stabilizes itself Removing any one species has significant effects on system behavior; simulated removal of fish species led to decreased overall fish production. The model identified future research needs in such areas as phosphorus release mechanisms, phytoplankton species composition, and toxic substances.