Synchronous blooms of the coccolithophoreEmiliania huxleyiand three dinoflagellates in the Dardanelles (Turkish Straits System)

Abstract

This study focuses on the synchronous blooms of the coccolithophore Emiliania huxleyi and three dinoflagellates Prorocentrum micans, Ceratium furca var. furca and Ceratium fusus var. seta observed between 7 June and 11 July 2003 in the Dardanelles. An analysis of the vertical distribution of the E. huxleyi population size with respect to various environmental parameters was discussed. Additionally, inorganic nutrients and phytoplankton interactions were investigated in relation to the bloom conditions and hydrography of the Dardanelles. The algal bloom started in nearby Izmit Bay (eastern end of the Sea of Marmara) in early June, then quickly spread through the Sea of Marmara and continued until mid-July. Thermal stratification was observed between different water masses at the time of sampling. During the bloom period, cell density of E. huxleyi ranged from 3.58 × 107 to 2.55 × 108 cells l−1 in the superficial layer. Prorocentrum micans was the second most-abundant species and the cell numbers ranged from 1.0 × 106 cells l−1 to 3.3 × 106 cells l−1. Other abundant species in this area included C. furca var. furca and C. fusus var. seta.

Untitled

“…Besides the temporal variations in the nutrient concentrations, especially the southern part of the Dardanelles receives notable nutrient inputs due to domestic wastes from the city of Canakkale and from the rivers such as Saricay and Kalabakli (Polat and Tugrul, 1996;Polat et al, 1998;Turkoglu et al, 2004bTurkoglu et al, , 2004cTurkoglu et al, , 2006Turkoglu, 2008). Therefore, in some periods of this study, extra accumulation of inorganic nutrients was highly pronounced.…”

“…Temperature along the southeast coasts of the Narrows (between Kilitbahir and Canakkale) is also lower than the other coasts of the Dardanelles due to upwelling and especially fresh water discharges from the rivers such as Saricay, Kalabakli and Karamenderes to surface layer (0-10 m) in early spring period. The surface waters in the southern part of the Dardanelles are also more saline especially in the spring and winter seasons compared to other seasons Turkoglu, 2008). Additionally, salinity variations effect behavior characters of the other bio-physicochemical variations due to different character of the lower layer waters.…”

“…Therefore, there is a high positive correlation between salinity and TDS due to the high NaCl in marine systems. pH can also be affected by higher salinity which tends to buffer pH in the 7-8 range and extensive algal blooms which can raise the pH over 8 in low-salinity waters (MD DNR, 2006) like in surface waters of the Dardanelles Turkoglu, 2008).…”

“…The Dardanelles surface water is more saline in the spring and winter compared to other seasons in the south east of the Dardanelles. When the salinity in the surface water is low, values of total dissolved solids (TDS) in the Dardanelles are lower (Unsal et al, 2003;Turkoglu et al, 2004aTurkoglu et al, , 2006Turkoglu, 2008) than those in other marine systems (≥35.0 mg L -1 ) (Xie et al, 2003). Temporal cycle of pH in the Dardanelles reveals fluctuations throughout the year, winter values were significantly lower (mean 8.20) than the spring (mean 8.36) and fall values (mean 8.28).…”

“…Temporal cycle of pH in the Dardanelles reveals fluctuations throughout the year, winter values were significantly lower (mean 8.20) than the spring (mean 8.36) and fall values (mean 8.28). DO concentrations vary generally from 6.00 to 10.0 mg L -1 during the year, being higher in the spring and winter compared to summer (Turkoglu et al, 2004b;Turkoglu, 2008).…”