Diversity of phytoplankton in Kucukcekmece Lagoon channel, Turkey

The composition and functional groups of phytoplankton in the channel from Kucukcekmece Lagoon to the Marmara Sea were investigated. Some water-quality parameters and nutrient variations were also recorded. Water samples were taken from the water surface between May-August 2008 at 5 sampling sites including the lake and the sea. A total of 28 taxa were recorded, including Charophyta (1), Chlorophyta (4), Cryptophyta (1), Cyanophyta (3), Dinophyta (5), Euglenozoa (2) and Ochrophyta (12). According to the functional-group approach, the populations formed by 13 groups were most common in mesotrophic and eutrophic water. The phytoplankton density (19-8842 individuals/cm 3 ) and chlorophyll-a content (4.45- 40.36 mg/m 3 ) varied in broad ranges. The data from certain water-quality parameters and some nutrient experiments showed variations related to sampling points. As a result, the minimum and maximum water-quality parameters and nutrient concentrations were found to be in normal ranges. No high levels of nutrients were recorded. The presence of pollution indicated by freshwater and marine species with high chlorophyll-a concentrations showed that the study area was eutrophic.