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

Abstract

The zooplankton fauna and the relationship with their environmental variables were investigatedon the epilimnion layer of the seven reservoirs (Demirdöven, Devegeçidi, Menzelet, Sır, Ömerli,Porsuk, Tahtalı) of different regions (Marmara, Aegean, Mediterranean, Central Anatolia, EasternAnatolia, Southeastern Anatolia) throughout the summer months (2015) in Turkey. According tothe trophic conditions reservoirs varied between oligo- and eutrophic status. Chlorophylla concentration, measured for the estimation of primary production, was determined considerably highalong the investigation period. A total of 62 zooplankton species were identified with the contribution of 44 rotifers, nine cladocerans and nine copepods. Except one reservoir, all of the otherswere dominated by rotifera group, and also in each study site dominant taxa were changed atspecies level. On the other hand common dominant taxa for all reservoirs was the rotifer Polyarthra vulgaris Carlin, 1943 with 95 % frequency. In terms of zooplankton species, most of the studied reservoirs showed less than 50% similarities, due to their different limnological conditions anddifferent geographic locations. Reservoirs in high trophic conditions in the present study wererepresented by low species diversity. Water quality in the reservoirs with respect to biological datawere determined as ß-mesosaprobic. The using limnological and biological indices to determinewater quality were consistent. Densities of main zooplankton groups, and also frequent species ofthe reservoirs correlated with epilimnion layer 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 relatedwith total phoshorus. The comperative assessment between limnological variables and zooplankton community in this reservoirs was studied for the first time.