SEASONAL VARIATIONS IN PRIMARY PRODUCTIVITY AND ITS RELATION TO SOME PHYSICO-CHEMICAL PROPERTIES OF WATER AT AL-ABBASSA FISH FARM

The present study was carried out to evaluate the primary productivity (gross, net and respiration) and its relation to some water quality parameters at Al-Abbassa fish farm (inlet, outlet and the fish ponds) and Ismailia canal which is the main feeder of this area. The study extended from April, 2014 to May, 2015. Physico- chemical parameters, gross primary production (GPP), net primary production (NPP) and community respiration (CR) were measured through dissolved oxygen determination in situ and laboratory. The results showed that, the Physico- chemical parameters of water were significantly different among different seasons and the studied sites. Concerning BOD annual mean results, all the studied sites are located in the clean range. Results of (GPP), (NPP) and (CR) are higher in the fishponds compared to the other studied sites. It is concluded that the primary productivity and trophic nature were affected by increased levels of nutrients in fish ponds, where they exhibited a heterotrophic nature compared to the other sites.