Picocyanobacteria and Bacteria in Lake Kinneret

In Lake Kinneret, we have been monitoring the numbers and depth distributions of bacteria and picocyanobacteria since early 1988. Picocyanobacteria were found throughout the year at all depths, at concentrations ranging from < 10³ to 10⁵ cells·ml⁻¹. Highest abundances were recorded during summer and fall in the epilimnion. The lowest areal standing stocks occurred from March to May, the period which corresponds to the peak of the annual dinoflagellate bloom. Bacterial numbers ranged from about 10⁵ to 10⁷ cells·ml⁻¹. The picocyanobacteria were evenly distributed in the water column during the mixed period. With the onset of thermal stratification and the end of the dinoflagellate bloom the numbers of picocyanobacteria increased rapidly in the epilimnion.