Zooplankton and yield in fish farming and rice ponds Rice-fish farming

The aim of this study is to compare zooplankton populations and yields in conventional and rice-fish culture ponds.The sampling campaigns will take place from June 2019 to May 2020 in the Bdiala sub-prefecture.Zooplankton were sampled in the ponds by filtering 100 litres of water using a 64 m mesh plankton net.Two ponds were used for rice cultivation, two ponds for fish cultivation and two ponds were used to cultivate rice and fish simultaneously.The results obtained show that the taxa identified in the fish culture ponds and the rice-fish culture ponds are distributed between three taxonomic groups : Copepods, Cladocerans and Rotifers.Taking rearing environments into account, 67.2% of taxa were collected in rice-fish culture ponds and 32.8% in conventional fish culture ponds.The highest densities (237 ind/L) were recorded in rice-fish culture ponds (t-test, p-value 0.05).Average yields of 7 0.02 t/ha/yr and 4.41 0.01 t/ha/yr were obtained at the end of the rice harvest in rice-fish culture and conventional rice culture respectively (X 2 , p-value 0.05).Rice-fish ponds showed a 22% improvement in yield compared with conventional rice ponds.Average fish yields in fish ponds and rice-fish ponds increased with continued rearing.Yields of 2.32 t/ha/year and 5.03 t/ha/year were obtained respectively in fish ponds and ricefish ponds with rice bran (X 2 , p-value 0.05).The rice-fish culture ponds have high yields because they are richer in food resources for the fish compared with conventional fish culture ponds.