IMPACT OF HIGH CO2 CONCENTRATIONS ON RED CORALLINE ALGAE G. <i>LITHOTHAMNION </i>(REVIEW)
Red coralline algae of the Lithothamnion genus incorporate pharmacologically active substances and are applied in medicinal and nutraceutical products as a source of mineral ingredients, which makes this genus of algae an important vegetal resource. However, Lithothamnion is not cultivated artificially but harvested in natural environment, where these algae are subjected to various influencing factors, including anthropogenic ones. In this paper, the studies of the impact of the increased CO2 concentrations on red coralline algae of the genus Lithothamnion are reviewed for the first time. Main effects of the increased CO2 concentrations, and, as a result, the increased НСО - concentration and the decreased pH, manifest in a range of changes. During the studies, the following changes were recorded: elongation of a cell, increase of its width, thinning of a cell wall (intra- and interfilamentous) in the case of short-term exposure, decrease in cytoplasm density and its transition to sol state, decrease in Mg deposition, leading to the increased cytoplasm resistivity upon its deformation resulted from the influence of Mg-unsaturated matrix, decrease in the solubility of algae skeletal structure, increase in inorganic carbon content and discoloration of algae, decrease in organic carbon content, decrease in calcification values, increase in primary production of the algae that did not possess carbon concentrating mechanisms and decrease in primary production of the species that possessed carbon concentrating mechanisms. Decreased photosynthetic activity was also recorded. Thus, the results of the research, focused on adverse effects of the increased carbon dioxide concentrations on red coralline algae of the Lithothamnion genus, are summarized.