Abundance and production of bacteria in a marine beach [Southern Baltic Sea]

The paper presents the results of the study of abundance, biomass, mean cell volume and secondary production of bacteria inhabiting a marine-bay sandy beach, at southern Baltic Sea coast (Sopot) in summer season. The differences of bacteriological parameters among sites across beach horizontal profile were determined. Maximal value of the total bacteria numbers (8.59 ± 0.73 × 10⁷ cells g⁻¹ dw), biomass (15.2 ± 4.4 μg C g⁻¹ dw) and cell volume of bacterium (0.056 ± 0.011 μm³) was noted at the waterline and bacterial secondary production was highest in the dune (172.3 ± 86.6 μg C g⁻¹ dw d⁻¹) and at the waterline (119.9 ± 40.5 μg C g ⁻¹ dw d⁻¹). Marked differences in the level of bacteriological parameters between surface and subsurface sand layers were estimated. In the sea, at the waterline and in the middle of the beach higher numbers of bacteria, their biomass and secondary production were found in the surface (0–1 cm) than in the subsurface (5–10 cm) sand layers. A reverse situation was observed in the dune.