The processes occurring at the marine water - atmosphere boundary layer and involving selected important components of our environment arc discussed. Special attention is focused on the specific role of the marine water surface microlayer in transfer of those components, properties of aerosols, fundamental question of CO2 absorption/desorption balance and environmental conditions enabling re-emission of mercury from marine water into the atmosphere. Simple laboratory experiments on CO2 absorption from atmosphere and desorption of CO2 from marine water arc shown as an initial point for any wider discussion on the global carbon budget. The emission of mercury to the atmosphere is considered to be promoted by the solar radiation. Under strong solar radiation the ability of organic matter to reduce these ions is enhanced thus making the emission more effective. The phenomenon observed seems to be confirmed by the analysis of the data for months of low and high radiation intensity. A sign i fi cant role of atmospheric iron in cutophication of southern Baltic is emphasized. Concentration of this clement in dry and wet deposition is, however, too low to prevent limitation of phytoplankton growth in marine water.

Measurements of water temperatures, salinity, oxygen, suspended matter, nutrients and some metals contents were determined in the waters of the Hornsund Fjord. The investigations were carried out at the end of June and July and in mid-September 1979.