Abstract. This research was investigated the seasonal changes in phytoplankton, bacterioplankton and autotrophic picoplankton as well environmental parameters photic layer of Lake Baikal. Using microscopy methods, 43 species belonging to Bacillariophyta, Dinophyta, Chlorophyta, Chrysophyta, Cryptophyta, Haptophyta, Charophyta Cyanoprokaryota have been identified. Bacillariophyta Chlorophyta wer...

Autotrophic picoplankton (APP) abundance and contribution to phytoplankton biomass was studied in Hungarian shallow lakes to test the effect of inorganic turbidity determining the size distribution of the phytoplankton. The studied lakes displayed wide turbidity (TSS: 4-2250 mg l-1) and phytoplankton biomass (chlorophyll a: 1-460 μg l-1) range, as well as APP abundance (0 and 100 million cells ...

Coastal pelagic environments are believed to feature concentration gradients of dissolved organic carbon at a microscale, and they are characterized by pronounced seasonal differences in substrate availability for the heterotrophic picoplankton. Microbial taxa that coexist in such habitats might thus differ in their ability to incorporate substrates at various concentrations. We investigated th...

We sampled extensively (29 stations) at the Klang estuarine system over a 3-day scientific expedition. We measured physical and chemical variables (temperature, salinity, dissolved oxygen, total suspended solids, dissolved inorganic nutrients) and related them to the spatial distribution of phototrophic picoplankton (Ppico). Multivariate analysis of variance of the physicochemical variables sho...

Abstract. In ultraoligotrophic lakes of Andean Patagonia, microbial assemblages at the base pelagic food webs bear high THg concentrations compared to planktonic consumers. this study, we evaluate experimentally passive and active (trophic) uptake Hg2+ using 197Hg2+ trace Hg incorporation in picoplankton (autotrophic heterotrophic bacteria), photoautotrophic phytoflagellate, Gymnodinium paradox...

Our current knowledge on the microbial component of zooplankton diet is limited, and it is generally assumed that bacteria-sized prey is not directly consumed by most mesozooplankton grazers in the marine food webs. We questioned this assumption and conducted field and laboratory studies to examine picocyanobacteria contribution to the diets of Baltic Sea zooplankton, including copepods. First,...

The clearance rates of co-occurring appendicularian species, Oikopleura longicauda and O. fusiformis, in Kaneohe Bay, Hawaii, were investigated to evaluate and compare their roles in a tropical food web. Individual appendicularians were captured in situ and allowed to feed on the natural plankton assemblage for 60 to 180 min. Feeding rate estimates were based on flow-cytometry analyses of cell-...

The relative contribution of various inorganic and organic forms of nitrogen to the nitrogen requirements of picoplankton was examined with 15N tracers. Size fractionation was used to measure uptake by < l-pm size microorganisms, and inhibitors of protein synthesis were used to separate procaryotic from eucaryotic nitrogen uptake, Picoplankton utilized mainly ammonium and amino acids and only n...