Zooplankton Biodiversity in Reservoirs of Different Geographical Regions of Turkey: Composition and Distribution Related with Some Environmental Conditions

The zooplanktonfauna and the relationship with their environmental variables were investigated on the epilimnionlayer of the seven reservoirs (Demirdoven, Devegecidi, Menzelet, Sir, Omerli, Porsuk, Tahtali) of different regions (Marmara, Aegean, Mediterranean, Central Anatolia, Eastern Anatolia, Southeastern Anatolia) throughout the summer months (2015) in Turkey. According to the trophic conditions reservoirs varied between oligo- and eutrophic status. Chlorophylla concentration, measured for the estimation of primary production, was determined considerably high along the investigation period. A total of 62 zooplanktonspecies were identified with the contribution of 44 rotifers, nine cladocerans and nine copepods. Except one reservoir, all of the others were dominated by rotifera group, and also in each study site dominant taxa were changed at species level. On the other hand common dominant taxa for all reservoirs was the rotiferPolyarthra vulgaris Carlin, 1943 with 95 % frequency. In terms of zooplanktonspecies, most of the studied reservoirs showed less than 50% similarities, due to their different limnologicalconditions and different geographic locations. Reservoirs in high trophic conditions in the present study were represented by low species diversity. Water quality in the reservoirs with respect to biological datawere determined as s-mesosaprobic. The using limnologicaland biological indices to determine water quality were consistent. Densities of main zooplanktongroups, and also frequent species of the reservoirs correlated with epilimnionlayer depths and total phoshorus concentrations significantly. On the other hand rotifera variation was affected mainly by physical variables (pH, temperature, dissolved oxygen concentration, conductivity), and crustacean variations were related with total phoshorus. The comperative assessment between limnologicalvariables and zooplanktoncommunity in this reservoirs was studied for the first time.