Chemical and phycological structure of surface microlayer and subsurface water in a southern Baltic Sea estuary

The surface microlayer of water (SML) is a unique ecotone found on all water bodies. It is an interphase for the exchange of matter between the hydrosphere and the atmosphere. This ecotone is capable of accumulating chemicals and microorganisms in amounts as high as 100-fold greater than those observed in the pelagic zone. Here we report on the accumulation of chemicals and phytoneuston in the SML of the estuarial Łebsko Lake located at the southern coast of the Baltic Sea in the unpolluted region of the World Biosphere Reserve: the Słowínski National Park in Poland. The physicochemical parameters and phytoplankton composition from the SML (thickness of 242± 40μm) were compared with those in subsurface water layers (SUB; 15 cm under the surface). A wide spectrum of chemical and microbiological analyses was performed to investigate the capacity to accumulate substances. Almost all analyzed trace metals (Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Ba, Pb), biogenic substances such as forms of phosphorus and nitrogen as well as chlorophyll a, pheophytin, and heterotrophic bacteria were detected at higher levels in SML than in SUB. Also, a greater number of taxa and higher abundance and biomass of phytoplankton were found in SML than in SUB. In contrast, some chemical parameters such as salinity components (Cl–, SO2– 4, Na+, K+, Mg2+, Ca2+) as well as pH occurred at a comparable level in SML and SUB. Physicochemical factors such as components of salinity in freshwater, brackish, and marine areas determined taxonomic composition, abundance, and biomass of phytoplankton and phytoneuston. Canonical correspondence analysis indicated the most significant chemical factors, such as nutrients and essential metals, affecting phytoplankton composition in the analyzed water layers. The degree of water salinity, chemical components such as metals, nutrients of water, and lotic and lentic environments influenced the qualitative and quantitative parameters of the phytoplankton and phytoneuston; hence, the common occurrence of resistant species such as Desmodesmous communis in the studied estuary and those characteristic of freshwater occurring only in the river stand, e. g., Woronichinia naegeliana and, for example, Chaetoceros decipiens occurring only in the sea

Phytoneuston and Chemical Composition of Surface Microlayer of Urban Water Bodies

The concentration of chemical and biological parameters in the ecotone of the surface microlayer (SML) occurring between the hydrosphere and the atmosphere of urban water bodies was investigated. Parallel, sub-surface water (SUB) analyses were carried out to compare the SML properties with the water column. The concentrations of trace metals, macronutrients, nutrients, chlorophyll a, pheophytin, abundance and biomass of phytoplankton and the number of heterotrophic bacteria in both studied layers were analyzed. Each of the studied groups of chemical parameters was characterized by specific properties of accumulation. Trace metals occurring in concentrations below 1 ppm, such as Al, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Zn and metalloid As, were accumulated to a higher degree in SML than in SUB. Macroelement concentrations, with the exception of Mg, were lower in the SML compared to the SUB. Nutrients, autotrophic and heterotrophic microorganisms occurred in the SML to a higher degree than in the SUB. Bacillariophyceae dominated the analyzed water bodies, which are typical for the spring period, as well as Chrysophyceae, Chlorophyceae, Dinophyceae and Euglenophyceae. Cyanobacteria dominated in one of the ponds. The abundance of individual phytoplankton groups was significantly correlated with Ca, K, Na, P-org, SO42−, F−, Al and Sr

Macroelements in the surface microlayer of water of urban ponds

Analyses were conducted concerning the accumulation of four metals representing the group of macroelements, i.e. sodium, potassium, calcium and magnesium in two ponds located in the city of Słupsk. Water samples for chemical analyses were collected from the surface microlayer using a Garrett net. At the same time subsurface water samples were collected. Concentrations of metals were determined using a mass spectrometer. Generally, amounts of sodium, potassium, calcium and magnesium were similar in surface microlayer and subsurface water. Only in the case of potassium and calcium was low enrichment observed in the surface microlayer in one pond, while the greatest extent for magnesium enrichment was observed in the spring period

The anthropogenic pollutants in urban ponds based on the example of Słupsk

In areas of urban infrastructure, ponds play an important role. They are places of rest and recreation, and they facilitate contact between city dwellers and the aquatic environment. They are also a place for living waterflow and ichthyofauna. Urban ponds are susceptible to anthropogenic influences, and their self-cleaning capacity is limited due to their small size. The city of Słupsk is located in northern Poland. Coal combustion in domestic boilers and transport cause dust emissions to be released into the atmosphere. The concentration of particulate matter and heavy metals in PM10 in Słupsk is much higher than in neighbouring village Gać. This affects metals deposition from the atmosphere. Two urban ponds in Słupsk were the object of the research. Sampling station No. 1 was located in the southern part of the Raj Pond situated deep into the forest area, a considerable distance from urban buildings. Sampling station No. 2 was located at the Juniorów Pond located near the city centre. Water samples were taken from a depth of 10 cm. To investigate the deposition from the atmosphere, atmospheric precipitation was collected in a collector located in the city of Słupsk. The concentrations of Li, Al, Cr, Mn, Fe, Ni, Se, As, V, Sr, Cd and Pb were analyzed in the obtained water samples. Measurements were made using an ICP-MS mass spectrometer. From the obtained results, it was observed that the concentrations of Li, Al, Cr, Mn, Fe, Se, Sr and Cd were higher at station No. 2 located near the city centre

The anthropogenic pollutants in urban ponds based on the example of Słupsk

In areas of urban infrastructure, ponds play an important role. They are places of rest and recreation, and they facilitate contact between city dwellers and the aquatic environment. They are also a place for living waterflow and ichthyofauna. Urban ponds are susceptible to anthropogenic influences, and their self-cleaning capacity is limited due to their small size. The city of Słupsk is located in northern Poland. Coal combustion in domestic boilers and transport cause dust emissions to be released into the atmosphere. The concentration of particulate matter and heavy metals in PM10 in Słupsk is much higher than in neighbouring village Gać. This affects metals deposition from the atmosphere. Two urban ponds in Słupsk were the object of the research. Sampling station No. 1 was located in the southern part of the Raj Pond situated deep into the forest area, a considerable distance from urban buildings. Sampling station No. 2 was located at the Juniorów Pond located near the city centre. Water samples were taken from a depth of 10 cm. To investigate the deposition from the atmosphere, atmospheric precipitation was collected in a collector located in the city of Słupsk. The concentrations of Li, Al, Cr, Mn, Fe, Ni, Se, As, V, Sr, Cd and Pb were analyzed in the obtained water samples. Measurements were made using an ICP-MS mass spectrometer. From the obtained results, it was observed that the concentrations of Li, Al, Cr, Mn, Fe, Se, Sr and Cd were higher at station No. 2 located near the city centre