Department of Biotechnology and Microbiology, University of Debrecen
Abstract: Earlier observations focused on ocean as the largest osmotic system that undergoes salinity fluctuations over geological ages, namely salination in ice ages and dilution in global melting periods. Such fluctuations in sea over geological ages represent a dynamic osmolyte system versus the theory of general geochemical balance that denies salinity changes. The osmolarity of blood of terrestrial vertebrates (~0.3 Osm) is reflecting the osmolarity of the primordial ocean at the time of their migration to land during the Devonian period some 400 million years ago. The osmotic concentration of the present day ocean (1.09 Osm) is now more than three times higher than that of the blood of land vertebrates referred to as the ’salinity gap’. In spite of divergent evolution of land vertebrates maintained a nearly identical blood osmolarity (~ 0.3 Osm), whereas to sea was subjected to a long-term salination process. The salinity increase of ocean is closely related to the global loss of freshwater. For the water deficit and the global loss of fresh water, several factors have been accounted for by including the photohydrolysis of water, biological oxidation of food molecules, releasing huge amounts of biogases containg the smallest hydrogen atom that escape to the outer space. The shrinking freshwater reservoirs (ice, glaciers, permanent snow) are limiting the sea level rise to about 50 m. Earlier sea level rises up to 200 to 400 m in the past 500 million years served to estimate the global freshwater loss and contribution to the salination of ocean. Data of sea level rises will be used to estimate the attrition of water on Earth, the amount of hydrogen escaped into the space and the inherent weight loss of Earth.
Brief Biography of the Speaker: