TY - JOUR AU - UYSAL, Z. AU - KOKSALAN, I. PY - 2010/10/08 Y2 - 2024/03/29 TI - Synechococcus dynamics in the Levantine basin shelf waters (northeastern Mediterranean) JF - Mediterranean Marine Science JA - Mediterr. Mar. Sci. VL - 11 IS - 2 SE - Research Article DO - 10.12681/mms.77 UR - https://ejournals.epublishing.ekt.gr/index.php/hcmr-med-mar-sc/article/view/12050 SP - 277-294 AB - <span>The abundance of picoplanktonic marine cyanobacteria </span><em>Synechococcus</em><span> was measured at weekly intervals over a period of one year in the northern Levantine basin shelf waters. </span><em>Synechococcus</em><span>was found more abundant during summer and early autumn and least during winter. Significant increases in abundances mostly occurred during very low nutrient concentrations either a week or two weeks after the nutrient enrichments. Cells were distributed homogenously in the water column due to intense mixing observed during winter. Despite the homogenous cell distribution attained during late autumn and winter, the magnitude of variation in cell abundances among depths was found greatest during August and September. Cell concentrations ranged from a minimum of 6.4 x 10</span><span style="font-size: xx-small;">3</span><span> to a maximum of 9.2 x 10</span><span style="font-size: xx-small;">4</span><span> cells ml</span><span style="font-size: xx-small;">-1</span><span> with an annual mean level of 2.5 x 10</span><span style="font-size: xx-small;">4</span><span>cells ml</span><span style="font-size: xx-small;">-1</span><span> at surface. Below the surface, it ranged from a minimum of 5.6 x 10</span><span style="font-size: xx-small;">3</span><span> to a maximum of 8.0 x 10</span><span style="font-size: xx-small;">4</span><span>cells ml</span><span style="font-size: xx-small;">-1</span><span> with an annual mean level of 2.1 x 10</span><span style="font-size: xx-small;">4</span><span> cells ml</span><span style="font-size: xx-small;">-1</span><span> at 25 m depth. Compared to surface and 25 m depth, lowest levels were attained at 50 m. At this depth, cell counts ranged from a minimum of 5.4 x 10</span><span style="font-size: xx-small;">3</span><span>to a maximum of 3.2 x 10</span><span style="font-size: xx-small;">4</span><span> cells ml</span><span style="font-size: xx-small;">-1</span><span> with an annual mean level of 1.4 x 10</span><span style="font-size: xx-small;">4</span><span> cells ml</span><span style="font-size: xx-small;">-1</span><span>. Based on Pearson-product moment correlation analysis, a highly significant correlation between </span><em>Synechococcus</em><span>abundance and ambient temperature was observed.</span><br /> ER -