Effects of the site and type of fertilizer on the structure and zooplankton distribution in fish farming ponds in the highlands of western cameroon

In order to contribute to the improvement of fry production, a study on the zooplanktonic productivity according to the site and type of fertilizer was conducted between January to December 2017. For this purpose, 15 ponds of which 03 in Bamendou fertilized with cowpat; 04 in Batié of which 02 fertilized with pig manure and 02 with Wheat bran; 01 in Dschang fertilized with chicken manure; 04 in Fokoué of which 02 fertilized with pig manure and 02 not fertilized and 03 in Foumbot fertilized with cowpat were chosen so as to determine the altitude variation and the type of fertilizer. Sampling of biotic and abiotic characteristics was done monthly. Results showed that the highest values of the temperature (23±00°C), pH (7.44±0.67 IU) and transparency (81.17±4.13 cm) were observed in the basins of Dschang fertilized with chicken manure. For the structure and distribution of zooplankton, the highest values of the densities (177±85 ind/L) and of biomass (24.64 g PS) of rotifers were noticed Batié fertilized with pig manure and the least values (15 ind/L et 0.14 g PS) in non fertilized ponds of Fokoué. Meanwhile, the density and the biomass of cladocerans (72 ind/L ; 102.2 g PS) and copepods (80 ind/L ; 91.18 g PS) were higher in ponds of Bamendou fertilized with cowpat. Then the structure and zooplankton distribution are affected by the site and type of fertilizer.