Zooplankton samples were collected on seasonal basis from King Talal Dam to determine the concentration of selected heavy metals, and to assess the possible use of zooplankton as bioindicator for heavy metals pollution. Zooplankton composition and biomass were determined in KTD. Horizontal gradient in temperature of the surface water of the dam was absence. A positive correlation has been found between chlorophyll a, zooplankton biomass and temperature, while the correlation with transparency was negative. The results showed that zooplankton in the size fraction (350-500 um) concentrate...