Tolerance and behavioral responses of zooplankton in different microhabitats

In the scope of this study holistic ecosystem structure has been revealed by examination of water quality values, zooplankton composition, population magnitude fluctuation and enzyme activity amount in zooplankton. For this purpose 5 sampling locations was selected from Karakaya Dam Lake. 14 sampling per month was made from the determined sampling between October 2010 and November 2011. In every sampling period water and zooplankton samples were taken to determine psycho-chemical values of the water, fauna of zooplankton and catalase, glutathione reductase, glutathione S-Transferase and acetylcholinesterase activity as biomarker values in Copepoda group (Cyclops scutifer, Microcyplops varicans) were determined. Among the zooplankton samples 14 belonging to Rotifera group, 6 belonging to Cladocera group, 2 belonging to Copepoda group and the rest as nauplius larvas (totally 22) were diagnosed. The most prevalent species were Synchaeta oblonga, Keratella cochlearis from Rotifera group, Bosminia longirostris from Cladocera group and Cyclops scutifer from Copepoda group. The distribution of defined types in sampling locations was analyzed according to frequency, density, dominancy and variety. These results were tested by canonical correspondences analysis (CCA). CCA was applied to two other data sets together with the environmental factors effecting zooplankton distribution. Looking at the CCA diagram, Lepadella patella, Brachionus calyciflorus, Cyclops scutifer, Chydorus sphaericus ve Keratella cochlearis, Lecane luna, Alona rectangula ve Daphnia cucullata are closely related with st.1 sampling location, Ascomorpha saltans, Ceriodaphnia reticulata, Kellicottia longispina, Keratella quadrata ve Polyarthra dolichoptera are closely related with st.3 and st.4 sampling locations and Trichocerca similis is closely related with st.5 sampling location. It was observed that other species distributions did not show any difference and gathered in the center. According to CCA results it was observed that st.1 and st.2 sampling locations are similar to each other and st.3, st.4 and st.5 sampling locations are similar to each other. When enzyme activities were evaluated in terms of sampling locations it was observed that CAT, GST and GR activity values of st.1 and st.2 sampling locations were lower than other sampling locations while AChE activity was in higher values. According to psycho-chemical values of the research area and CAT, GST, AChE enzyme activity values of zooplankton, a periodical pollution was detected in spring season. KEY WORDS: Zooplankton, water quality, antioxidant enzyme, Karakaya Dam Lake, biomonitoring, canonical correspondence analysis (CCA).