Interannual and seasonal changes in the distribution and ecological responses of zooplankton communities in Lake Eğirdir (Türkiye).

The aim of the present study was to analyze interannual and seasonal relationshisps between zooplankton communities and their trophic levels along with the physicochemical properties of Lake Eğirdir. Samplings were performed seasonally between January 2016 and October 2018 at five stations. Zooplankton communities comprised Rotifera (88%), Cladocera (3%) and Copepoda (9%). A total of 73 species were recorded. Four species Asplanchna priodonta, Polyarthra dolichoptera, Synchaeta pectinata and Bosmina longirostris were found dominant among the others. During the study, the number of zooplankton species decreased in 2018 compared to 2016 when the average zooplankton density increased in 2018. The variations of zooplankton community were estimated using Shannon–Wiener diversity, Evenness, and Simpson indices. The correlations between the species and environmental variables were analyzed with Canonical Correspondence Analysis (CCA). The variation in the species data was significantly (p < 0.05) related to a set of six environmental variables (electrical conductivity, chloride, ammonium, carbon, depth, temperature) which explains 84.6% of the total variation. CCA indicated that Keratella cochlearis, Lecane bulla, L. clostrocerca, Trichocerca similis and Copepoda spp. were positively correlated with temperature. According to the Brachionus: Trichocerca quotient (QB/T), Lake Eğirdir can be characterized within the mesotrophic-eutrophic trophic status. The lake showed mesotrophic status in terms of total phosphorus, Secchi disc and chl-a in 2016, 2017, 2018 according to the Carlson trophic status index. [ABSTRACT FROM AUTHOR]