Phytoplankton, National Monitoring Study 2019, EMBLAS Plus Project

Method steps

1. Bacillariophyceae, Chlorodendrophyceae, Chlorophyceae, Chrysophyceae, Cryptophyceae, Cyanophyceae, Dictyochophyceae, Dinophyceae, Ebriophyceae, Euglenoidea, Imbricatea, Prasinophyceae, Prymnesiophyceae, Trebouxiophyceae, Ulvophyceae, Xanthophyceae
   rank: class

"Data collected within the EMBLAS-Plus “EU-UNDP Project 'Improving Environmental Monitoring in the Black Sea' (EMBLAS-Plus)” (http://emblasproject.org/). Quantitative phytoplankton samples (35 samples at 20 stations) were collected by vertical series consisting from several sampling depths, so that the material could be collected from main hydrophysical layers. Layers at each station were identified according to CTD-sounding, conducted prior the phytoplankton sampling. Special attention was paid to fluorescence profile obtained simultaneously with the CTD-sounding. Depending on the features of the station, the samples in NMS were collected from upper mixed (0-1m) layer, upper thermocline layer, lower thermocline layer, near-bottom layer. Were used 5L Niskis bottles, attached to CTD rosette system for sampling at each depth; 1-2 L water samples were taken during NMS. Samples of the phytoplankton were fixed with 4% buffered formaldehyde up to the final concentration of 2% in a sample and delivered to the laboratory. After sedimentation of the phytoplankton cells during 2 weeks, samples were slowly decanted to 30-40 ml. These concentrated samples were kept at temperature of 5-7 oC during a month before further processing. Before counting, the concentrated samples were concentrated one more time, down to 10-20 cm3 by slow decantation. Identification of species and cells counting were carried out under a light microscope with magnifications of 600 in the drop with the volume of 0.05 ml (Naguotte chamber). The wet biomass was calculated by the method of geometric similarity equating shapes of cells to corresponding geometrical shapes and assuming that the cell density is equal to 1. Species were identified mainly using Schiller (1937), Kisselew (1950), Carmelo (1997), Steidinger and Tangen (1997), Cronberg and Annadotter (2006) and the taxonomic nomenclature according to the on-line data-base of World Register of Marine Species (WoRMS) and the Black Sea check-list http://phyto.bss.ibss.org.ua."