Measurement of heavy metal concentrations and microbiological parameters in the surface microlayer of a downtown pond

Phytoneuston and Chemical Composition of Surface Microlayer of Urban Water Bodies

“…Most research concerning the phytoneuston focuses on studies on primary production and analyses of photosynthetic pigments, primarily chlorophyll a, rather than the phytoneuston species composition or population size. The abundance of algae and cyanobacteria in the present study was higher in the SML than in the SUB, similar to other studies carried out in other places and conditions [10,29]; it was analogous to the contents of nutrients and trace metals [14,47].…”

“…Moreover, high N-NO 3 concentrations were recorded in the lake, which may have been a consequence of N-NO 3 leaching from the catchment [37][38][39][40] and biological nitrification of ammonium nitrogen in the lake, particularly since good aerobic conditions were recorded there. Levels of nutrients in the studied water bodies indicate their eutrophic and hypereutrophic character, which is consistent with their levels reported in previous studies [10,18,41]. Concentrations of trace metals Mn, Sr, Zn, Se and V in the SUB (Figure 2) were higher in the ponds than in the lake; in contrast, higher concentrations of Cd, Ni and Al were recorded in the lake.…”

“…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.…”

“…Ponds located in Słupsk are inhabited by such fish species as Rutilus rutilus (roach), Carassius carassius (crucian), Abramis brama (bream), Tinca tinca (tench) and Esox lucius (pike) [17]. Urban ponds in Słupsk are also habitats for waterfowl, e.g., swans and ducks [10]. The presence of these animals increases the value of leisure in urban ponds.…”

“…In turn, such substances as calcium, magnesium, potassium or sodium, being macroelements found at high concentrations in the pelagic zone, are usually not accumulated in the SML [9]. The SML is inhabited by neustonic autotrophic and heterotrophic microorganisms, which exhibit both enzymatic and high respiratory activity [5,[10][11][12]. The SML structure may be disturbed as a result of physical non-equilibrium processes such as temperature fluxes, irradiance, wind and wave action that influence its biogeochemical properties.…”