The Structure of Algal Communities in the Parches Aquatic Ecosystem, Tulcea County (Romania)

Phytoplankton represents one of the most important communities of organisms for life in aquatic environments. It is a type of autotrophic pelagic organism that is unable to oppose the action of currents and is therefore widespread in all types of aquatic ecosystems. They are important for ecosystems and biodiversity development because they are primary producers. This means that they form the basis of food webs in aquatic environments. The present paper presents information about the phytoplankton structure in the Parches aquatic ecosystem, Tulcea County (Romania). Phytoplankton samples were taken in September 2021, at the end of the vegetative season, from 4 stations. Phytoplankton was present in all the stations we analysed. By processing the phytoplankton samples taken, four taxonomic groups were highlighted, namely: Baccilariophyceae, Euglenophyceae, Chlorophyceae and Cyanophytes. A total of 58 species belonging to the four taxonomic groups were identified. The dominant species are Cymatopleura solea, Cocconeis placentula, Melosira granulate. In the samples taken in September 2021, the abundance of Bacillariophyceae varies between 52-69%, followed by Chlorophyceae between 14 and 28%, and Euglenophycin between 9 and 14%. Cyanophytes had the lowest abundance between 0 and 10%. The number of taxa and specimens identified in the phytoplankton structure shows a good diversity of the phytoplankton community during the study period.