TURKISH JOURNAL OF FISHERIES AND AQUATIC SCIENCES, vol.10, no.4, pp.537-548, 2010 (SCI-Expanded)
Abstract: This study was carried out to determine the short time series of phytoplankton density and chlorophyll a in relation to nutrients and other environmental parameters in surface waters of Kepez harbor in the Dardanelles in winter period of 02 December 2004 and 07 March 2005. Average temperature, salinity, pH, specific conductivity, TDS, DO, TSS, NO-2+NO-3, PO-34, SiO4 and chlorophyll a were measured 9.47°C, 27.5 ppt, 8.12, 42.86 mS cm-1, 27.86 g L-1, 9.23 mg L-1, 27.1 mg L-1, 0.43 μM, 0.23 μM, 2.91 μM, 1.919 μg L-1, respectively. Both N:P (1.78) and Si:P ratios (14.9) were significantly lower than the assimilatory optimal Redfield ratio. Total phytoplankton density varied between 8.25E+04 and 4.71E+06 Cell L-1. Phytoplankton community structure was observed to be controlled by 3 dinoflagellates and 4 diatoms in the Dardanelles. However, there also were blooms of coccolithophoride Emiliania huxleyi in early December (2.36E+06 Cells L-1) and late February (1.57E+06 Cells L-1) and some silicoflagellates such as Dictyocha spp. in early February (2.36E+05 Cells L-1). Contribution of diatoms to total phytoplankton density (48.8%) was higher than the contribution of dinoflagellates (30.9%) and other taxonomic groups (20.3%). Relationships between chlorophyll a and diatoms (r=0.726), between chlorophyll a and
dinoflagellates (r=0.579) and between chlorophyll a and other taxonomic groups (r=0.514) showed that chlorophyll a was highly controlled by diatoms than dinoflagellates and other taxonomic groups. On the other hand, short time distribution of
phytoplankton revealed that there was growing 7 phytoplankton populations in the winter period. High chlorophyll a, nutrient, phytoplankton density and rational differences between major taxonomic groups revealed that the Dardanelles was connected with the process of eutrophication due to high terrestrial discharges coming from Black Sea surface waters via straits system and international carrying activities by vessels.
Keywords: Dardanelles, phytoplankton, short time variations, winter, environmental parameters, eutrophication.