Chemical and Phycological Structure of Surface Microlayer and Subsurface Water in a Southern Baltic Sea Estuary

Phytoneuston and Chemical Composition of Surface Microlayer of Urban Water Bodies

“…Neuston bacterial counts expressed in CFU were more numerous compared to the bacterial populations in the SUB, which may be explained by the higher concentrations of organic substance recorded in the SML [90]. Analogous densities of heterotrophic bacteria have also been reported in other water bodies such as Jeziorak Mały [91] or Lake Łebsko [6]. The studied heterotrophic bacteria usually accumulated more in SML than in the SUB.…”

“…Chemical substances and organisms are supplied to the SML from subsurface water and the atmosphere. Greater accumulation of trace metals in the SML compared to the SUB has also been observed in other inland waters, both lotic and lentic as well as marine [6,7,10]. In the case of trace metals, the recorded EF values for the investigated urbanized water bodies were particularly high for Cd and V. They are the elements found at slight concentrations in the SUB layer.…”

“…The SML supply from the water column occurs during the movement of matter from deeper layers to the surface together with gas bubbles raised from the bottom of the water body and the surface of plants and diffusion movements [3]. Moreover, neustonic organisms, usually derived from the SUB [2], have the ability to bioaccumulate metals [6] and thus can affect the enrichment and chemical composition of the SML. In view of the above, it may be assumed that Sr, Zn, Ca, Cl − , Na and K mainly originated from the pool accumulated earlier in the SUB layer, particularly since the concentrations of these elements in the atmosphere are much lower when compared with those recorded in the SUB layer [13,17].…”

“…The accumulation of chemical substances in the SML may vary, as it is dependent on many factors such as the chemical composition of water, salinity, the nutrient status and the presence of neustonic organisms (organisms that live upon the upper surface of waters or beneath its surface film, the SML) [5,6]. The SML may also accumulate toxic substances at greater amounts than observed in the pelagic zone [7].…”