Phytoplankton distribution in the western and eastern Black Sea in spring and autumn 1995

Abstract

Species composition, abundance, and biomass of micro-(>15 m) and nano-(<15 m) phytoplankton were studied in the western and eastern Black Sea during March-April and October 1995. A total of 142 species were identified, of which >50% were dinoflagellates. Abundance and biomass values were lower during the March-April period (average 129 28 thousand cells l 1 and 330 124 g l 1) than during the October period (average 364 161 thousand cells l 1 and 1794 515 g l 1) and compared with previous investigations. Values for the north-westerly region were higher than for the southerly areas, probably owing to effects of the Danube river, but were much lower than previously reported, possibly indicating improved ecological conditions. In March-April, dinoflagellates (mainly Heterocapsa triquetra and Scrippsiella trochoideum) were the most important groups, whereas, in October, diatoms (mainly Pseudosolenia calcar-avis) and coccolithophores (Emiliania huxleyi) were dominant. Nanophytoplankton constituted 57% and 84% of total abundance and 8% and 3% of total biomass in spring and autumn, respectively. Microphytoplankton were dominant in the western Black Sea, whilst nanophytoplankton were dominant in the eastern region in spring.

The effects of the Three Gorges Dam’s (TGD’s) experimental impoundment on the phytoplankton community in the Xiangxi River, China

“…Phytoplankton samples were preserved immediately in 1% Lugol solution. A sedimentation method was used for taxonomic identification and algal cell counting [27,28]. Phytoplankton was identified and counted using a Sedgwick-Rafter chamber with the standard light microscope (OLYMPUS C41); before counting, the whole sample was gently mixed.…”

Distribution of phytoplankton in the Three-Gorge Reservoir during rainy and dry seasons

“…A sedimentation method was used for taxon identification and counting (Zhang and Huang, 1991;Eker et al, 1999). Phytoplankton was counted with a standard light microscope (OLYMPUS C41).…”

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“…This might be due to the multifactoral interactions of phytoplankton communities and the non-linearity of the responses. Previous studies showed that small-sized microphytoplankton species were dominant in the studied area (Eker et al, 1999;Eker and Kıdeys, 2003). This may be attributed to the presence of small cells having problems of microscopic identification and to the difficulty in determination of their biomass (Llewellyn at al 2005).…”