The Effect of Trophic State and the Other Physicochemical Variables on the Dynamic of Benthic Macroinvertebrates of Küçükçekmece Lagoon Lake (Turkey, İstanbul)

Abstract

In this study, for determining the effect of trophic state and the other physicochemical variables on the dynamic of benthic macroinvertebrates of Küçükçekmece Lagoon Lake, water and sediment sampling were performed at five stations at seasonally during a year between 2014-2015. A total of 6 benthic macroinvertebrates taxa comprised of 350 individuals per m2 at average were found in the lake. The water samples analysed to determine physicochemical variables (water tempature, pH, conductivity, DO (dissolved oxygen), TDS (total dissolved solids), salinity. NO3-N, NO2-N, SO4-2, PO4-3, SiO2, chlorophyll-a, TP (total phosphorus), and secchi disc) and the similarity of seasons and stations in the lake in relative to the benthic macroinvertebrates and physicochemical variables were showed by Bray-Curtis Similarity Index. According to the Carlson Trophic State Index (CTSI) made to determine the trophic state, the water of the lake showed a eutrophic character during all seasons of the year. In addition, the relations between physicochemical variables and benthic macroinvertebrates were compared statistically by Canonical Correlation Analysis (CCA). As a results, it was concluded that the dominance of the taxa detected from the lake was quite low and this was due to the eutrophic conditions that occurred as a result of the increasing pollution in the lake.