Response of marine microalgae Phaeodactylum tricornutum, Prorocentrum cordatum and Gyrodinium fissum to complex pollution of Sevastopol bays (Black Sea)

For the degrees of toxicity assessment within the Black Sea surface coastal waters near Sevastopol, laboratory experiments were performed on three marine microalgae species culture’s growth in water sampled on the three stations of the region from May to December 2020. The study has indicated, that in the majority of cases, insignificant inhibiting influences of the waters to diatom Phaeodactylum tricornutum Bohlin and insignificant stimulated effect to dinoflagellates Prorocentrum сordatum (Ostenfeld) J.D.Dodge and Gyrodinium fissum (Levander) Kofoid & Swezy were observed. Rarely this effect was characterized as chronic or subacute. The concentration levels of both stable and unstable forms of organic substances in the studied waters were estimated. The results of the testing of the water to determine its contamination using microalgae and analysis of the organic substances concentration levels in them, allowed the conclusion that the studied area should be classified as episodically polluted. Justification for the necessity to use several microalgae species of different taxonomic affiliation when performing marine water biotesting is provided in this study.