In aquatic ecosystems primary producers are phytoplankton species, which are used as
indicator organisms for detection of water pollution because of their sensitivity towards rapid
aquatic changes [11, 12]. Phytoplankton species are indicated by their functional groups in terms of
their tolerance and sensivity level to different combinations of physicochemical and biological
properties of aquatic systems [13, 14]. Dangerous pollution levels in Kucukcekmece Lagoon are
anthropogenic [5, 7, 10]. Phytoplankton diversity, trophic structure, productivity and nutrient levels
are important factors for determining and monitoring the pollution rate in the lagoon. This paper
reports on the composition and functional groups of phytoplankton related to specific water quality
parameters and nutrients along the channel joining Kucukcekmece Lagoon to the Marmara Sea.