Physical, Chemical, Biological properties and fish species type of Geray reservoir, -W/Gojjam Zone, Ethiopia

The aim of the present study was to determine the physical, chemical and biological characteristics and to characterize the fishery of Geray reservoir. Three sites from the inlet site, the open water and the outlet has been selected and samples were collected using YSI 556MPS model multimeter and Palin test photometer 5000 .Temperature, pH, dissolved oxygen, salinity, Total Dissolved Solid, conductivity, secchi disk measurement, alkalinity, nitrate, phosphate, ammonia and turbidity were the parameters measured. Plankton sample collected using 55 and 80 micrometer mesh net. The most abund taxon was copepoda (666 ind. /m3 of water with their juvenile stages “Nauplia” or contributed 85% of total zooplankton taxa), which was followed by Cladocera (190 inds. /m3 or 15%). Among the 3 study sites the open water site showed higher density of zooplankton, especially cyclopod followed by outlet site.