engleski

Seasonal variability of size fractionated phytoplankton biomass: a comparative study in two eastern Adriatic Sea coastal systems

Seasonal dynamics of phytoplankton taxonomic composition and biomass was analysed during 2008/2009 in two semi-enclosed bays: Lim Bay and Boka Kotorska Bay located in the northeastern and southeastern coastal area of Adriatic Sea, respectively. Both coastal carstic systems are characterized by increased nutrient input due to considerable precipitation quantities and strong freshwater inflow from numerous streams and submarine karstic springs (vruljas). The scope of this work was to determine differences between two systems in terms of phytoplankton size fraction biomass distribution: picoplankton (0.2–2 µm), nanoplankton (2–20 µm) and microplankton (20–200 µm). The smallest size fraction was investigated by means of flow cytometry and larger fractions by means of inverted light microscope. In both systems, spring and late winter period was characterized by microphytoplankton domination up to 90% of total phytoplankton biomass. In summer the most prominent were picoplanktonic cyanobacteria Synechococcus sp. which contributed up to 90% of total biomass in both systems. In Kotor Bay cyanobacteria contributed up to 60% in autumn while in Lim bay microphytoplankton dominated in 70% of total biomass. Contribution of nanoplanktonic cells was rather low in both systems, except in the spring when the larger contribution of coccolithophorids and autotrophic flagellates was recorded.

phytoplankton; biomass; size fractions; Kotor Bay; Lim Bay;

nije evidentirano