Seasonal variations of microphytoplankton assemblages and environmental variables in the coastal zone of Bozcaada Island in the Aegean Sea (NE Mediterranean Sea)

Abstract

Seasonal changes in the microphytoplankton assemblages were examined in the coastal zone of Bozcaada Island with regard to some major physical and chemical variables. Samples were collected from May 2000 to December 2001 at four stations. A total of 108 dinoflagellates, 102 diatoms, 1 chrysophycean, 3 dictyochophycean, and 1 prasinophycean species were identified and quantified during the study period. Diatoms and dinoflagellates were the most important in terms of species number and abundance. The maximum values of total microphytoplankton were observed at 0.5 m depth (46.2 9 10 3 cells l -1 at st. 3) in May as this was the month when the diatom Pseudonitzschia pungens bloomed. Chlorophyll (chl) a concentration ranged between 0.08 (August) and 0.78 lg l -1 (February). May was another important month in which chlorophyll a increased (0.41-0.47 lg l -1 ). Species diversity values (H 0 log2 ) ranged from 1.66 bits (June, 20 m) to 4.11 bits (November, 0.5 m). The increase was attributed to a more balanced distribution of abundance among species. The amounts of nitrate + nitrite (0.6-3.7 lg-at N l -1 ), phosphate (0.2-0.6 lg-at P l -1 ) and silicate (0.7-2.5 lg-at Si l -1 ) were recorded on each sampling occasion. Nutrient concentrations and chl a values of the research area were found to be poorer than those of the many other coastal areas in the northeastern Mediterranean. The mean atomic ratio of nitrogen to phosphorus varied from 1.3 (June) to 12.9 (February). This ratio was lower than the Redfield ratio of 16 for ocean phytoplankton, and phytoplankton was potentially limited by nitrogen for most of the months. The result of this study confirms and emphasizes the oligotrophic nature of the eastern Mediterranean.

Interannual variability of the Mediterranean trophic regimes from ocean color satellites

“…Intense deep convection events were reported in 2005, 2006winters (Civitarese et al, 2010Bensi et al, 2013) when the area is classed as "Bloom #5". Less intense convection, reported for the winters 2000, 2008, 2009(Gacic et al, 2002Bensi et al, 2013), seems to be associated with "Intermediate #4" or "No Bloom #5" regimes.…”

“…In the North Aegean Sea, the influence of the rivers and of the Black Sea Water on the phytoplankton productivity has been recently confirmed (Tsiaras et al, 2012. The load of nutrients in these areas by the river and/or the Black Sea Water in late spring (in May, Balkis, 2009) could also explain the occurrence of the "Anomalous #2" trophic regime, which presents a "plateau" in May, instead of the "No Bloom #2" trophic regime. At an interannual level, however, no trends or correlations have been identified.…”

Phytoplankton composition and abundance in the coastal waters of the Datça and Bozburun Peninsulas, south-eastern Aegean Sea (Turkey)

“…Some previous studies carried out in the eastern Mediterranean and Aegean Seas have shown that this region has oligotrophic characteristics (Azov 1991;Krom et al, 1991;Ignatiades et al, 2002;Turley et al, 2000;Balkis, 2009).…”

“…A number of studies on phytoplankton communities, dealing mainly with taxonomy, ecology and biomass distribution, have been carried out in the north-eastern Mediterranean Sea (Kideyş et al, 1989;Eker & Kideyş, 2000, Polat et al, 2000Polat & Işik, 2002;Polat, 2002;Polat & Piner, 2002a;Polat & Piner, 2002b;Polat et al, 2005;Eker-Develi et al, 2006;Polat, 2007;Polat & Koray, 2007;Balkis, 2009;Ozman-Say & Balkis, 2012). The Datça-Bozburun Specially Protected Area is one of thirteen specially protected areas in Turkey.…”

Nemrut Bay Seawater Quality Assessment at the Planning Stage of Marine Outfall

“…Table 3, were at eutrophic range in February (0.47-13.09 μM) and at mesotrophic range in July (0.30-2.28 μM) according to criteria provided for Aegean and Mediterranean coastal waters (Balkıs, 2009;Redfield, 1958). PO4…”