Epipelic and Epipsammic Microalgae Responses to Environmental Parameters: The Black Sea Case Study (Gulf of Odesa, Ukraine)

Being part of autotrophic system in the sandy beaches epipelic and epipsammic microalgae play an essential role in primary production formation and transferring elements through the food chain. Acting as mixotrophs, they also participate in reduction of organic matter. But it is still less known about their response to pull of environmental factors. In particular, what is the range of main environmental parameters in sand supralittoral. The aim of this paper was to see the interaction between microalgae abundance and 14 environmental factors during field multifactoral experiment: 5 parameters describing sand grain composition, nutrients, temperature and salinity of water, hydrodynamics and water toxicity. We also analyzed the biodiversity of epipelic and epipsammic microalgae and their distribution in the North Western Black Sea. We revealed 76 taxa of microalgae: 39% epipelic and 27% epipsammic. The priority factor for psammon algal community in any season is size of sand grains and dissolved silicates. Other variables depend on the season: while in summer, inorganic nitrogen (nitrates and nitrites) effects the microphytes more intensively than others, in autumn it is replaced by organic nitrogen and silty fraction.