The paper presents the findings of experiments to determine marine aerosol emission from the coastal zone. A relation between aerosol flux and wave energy dissipation was found. The emission fluxes calculated for the distribution of aerosol concentration are proportional to the dissipation of wave energy to the power of 3/4. The calculations were carried out using the experimental data obtained during the TABEX and BAEX experiments.
The aim of the study was to analyse the balance of mercury (Hg), i.e. the content of this metal, its inflow and outflow, in the ecosystem of the Bay of Puck. Based on literature data and the results of the author’s own study, this analysis has shown that the main source of Hg pollution is the atmosphere. An estimated 1.1–3.8 kg of Hg enters annually from the atmosphere, whereas the mass of Hg carried there by river waters per annum is about 7 times lower (0.13–0.44 kg year−1). The 0.9 –2.7 kg year−1 of Hg released from Bay of Puck waters to the atmosphere is of the same order as the quantity deposited from the atmosphere. The total amount of Hg deposited in the upper (0–5 cm deep) layer of the sediments has been estimated at 240–320 kg, its rate of entry being c. 2.25–2.81 kg year−1. 0.25–1.25 kg year−1 of Hg are released from the bottom sediments to bulk water, while 0.61–0.97 kg remains confined in aquatic organisms, including 133 g in the phytobenthos, 2.6 g in the zooplankton, 420–781 g in the macrozoobenthos and 34 g in fish.
The erythrocytes from Morris Hepatoma 5123 bearing rats took up Na+ and K+ ions from the incubation medium and released Na into the extracellular space at lower rates than did erythrocytes from intact control rats* The lipid composition of erythrocytes membranes from the tumor-bearing rats differed from that of membranes from unaffected rats, showing increased contents of phospholipid phosphorus and a decreased content of cholesterol, resulting in decreased choleste- rol: phospholipid molar ratios.
Particulate organic carbon (POC) and nitrogen (PON) concentrations and fluxes were measured during an experiment in the Gdańsk Deep in late spring (30.05. –06.06.2001). The vertical POC and PON concentration profiles were characterised by the highest values in the euphotic layer,a gradual decrease with depth, and an increase below the halocline. The hydrophysical conditions had a decisive impact on POC and PON fluxes in the water column. Preferential removal of nitrogen from suspended mater was observed in the entire water column (maximum – in the vicinity of thermocline). There were also differences in the diurnal effectiveness of nitrogen removal as compared to carbon removal. The removal rate was highest at night.
Nitrogen flow through birch stand canopies was studied in the Kampinos National Park (large forested area with inland dunes and wetlands close to Warsaw) during the growing seasons (April-October) of 2005–2006. The amount of nitrogen deposition including main forms like NO₃, NH₄, organic N and the aerosolgaseous fraction of deposition were estimated as well as the influence of birch canopies on this process. Because a method of “artificial foliage” allows to measure an aerosol-gaseous fraction of deposition a gradient of rain collectors equipped with artificial foliage of known surfaces were used. The results were compared with amounts of nitrogen measured in the throughfall of three birch forests. All stands (age 20–50 years) were rather similar, but stand II has smaller LAI (Leaf Area Index = 2.5 m² m⁻²) than stands II and III (3.8 and 3.9 m² m⁻²). It was found that nitrogen deposition in the Kampinos National Park is rather high – 1.6 kg ha⁻¹ month⁻¹. Ammoniumnitrogen made almost half of this value, organic nitrogen – over one third, and nitrate-nitrogen constituted the rest. Aerosol-gaseous input significantly made the deposition increased only in the case of nitrate-nitrogen, but deposition of ammonium- and organic nitrogen were similar and independent of catching leaf area. All fractions of nitrogen were effectively taken up during their passing through birch canopies (57% of nitrogen deposition was retained). Generally two thirds of deposited ammonium-nitrogen, more than half of organic N, and one third of nitratenitrogen were taken up by birch canopies. However, uptake efficiency of all N forms was lower for stand with smallest leaf area with no statistically significant retention of organic N.
Extreme toxicity of some species of mercury, the ability of this element to bioaccumulate in particular in fish meat, and the known cases of lethal poisoning by mercury have drawn particular attention to this element's presence in the natural environment. Due to the relatively long time of its presence in the air, elemental mercury can be transported over large distances, hence the presence of mercury of anthropogenic origin is detected practically all over the world. Apart from the elemental mercury, the main species of mercury in water are Hg(II) and mercury-organic species, in particular methylmercury. The latter undergoes strong bioaccumulation in living organisms and concentration in the trophic chains. That is why the relative concentration of mercury in organisms is determined by its presence in water. The concentration of mercury in water is related to the processes of methylation and demethylation, influenced by biotic and abiotic factors such as the activity of microogranisms, access to oxygen, illumination, temperature, pH and others. Despite intense studies, full and reliable recognition of the ecological and health effects of pollution by this toxic metal is still impossible. The aim of this paper is to present the problems related to speciation of mercury, and describe some conversion and migration processes of mercury in the water environment.