Optimization of integrated multi-trophic aquaculture systems for the giant freshwater prawn Macrobrachium rosenbergii

Abstract

Traditional monoculture farming of the giant freshwater prawn Macrobrachium rosenbergii causes a deterioration in water quality as a result of effluent discharge, leading to frequent disease outbreaks and environmental pollution. In the present study, the effects of integrated multitrophic aquaculture (IMTA) systems on the growth of M. rosenbergii and water quality were evaluated. Six treatments, with 4 replicates each, were used, including prawn monoculture (MP), prawn with aquatic plants (Lemna minor) (PP), prawn with silver carp Hypophthalmichthys molitrix (PF), prawn with mussels (Anodonta sp.) and H. molitrix (PMF), prawn with Anodonta sp. and L. minor (PMP) and prawn with Anodonta sp., L. minor and H. molitrix (PMPF). Growth rates of M. rosenbergii and physical, chemical and biological parameters were assessed every 10 d and on the last day of the 64 d experiment. Average weight gain in M. rosenbergii was highest in the PMPF group, although this was not statistically significant. There was also no significant difference in survival rate among treatments. Dissolved oxygen concentrations were significantly higher in the PMPF group, whereas total nitrogen and chlorophyll a concentrations were highest in the PF group. Compared to the MP group, stocking with H. molitrix (PF, PMF and PMPF) effectively reduced PO4P. L. minor exhibited effective uptake of both N and P. In contrast to the group stocked only with H. molitrix (PF), stocking with L. minor (PP and PMP groups) reduced phytoplankton biomass. In summary, culturing M. rosenbergii in a multitrophic PMPF system provides the potential for increased economic profits and ecological benefits.