Использование морских микроводорослей для биотестирования вод Севастопольских бухт

Abstract

For biotesting the marine environment, multicellular organisms are often used, primarily fish and their embryos. However, microalgae are still not used sufficiently enough for this purpose, the number of tested species is extremely limited. The aim of this work was to study the response of three species of planktonic microalgae to the complex pollution of the Black Sea coastal waters in the Sevastopol region and to assess the possibility of their application for biotesting. The studies were carried out on the diatom Phaeodactylum tricornutum and two dinoflagellates Prorocentrum cordatum and Gyrodinium fissum. To characterize the level of pollution of surface waters with organic substances, two indicators were used: BOС5 (biological oxygen consumption) and permanganate oxidizability. Evaluation of the effect of the water sample pollution on microalgae was carried out by the comparison between the coefficient of increase in the abundance of microalgae cells (Xk) in the experiment and the control one. Laboratory experiments carried out in the summer and autumn periods made it possible to reveal, in most cases, a weak depressing effect of the studied waters pollution on the microalgae growth. Occasionally, this effect reached a chronic level. In the summer period (in June), a stimulating effect of water pollution on the growth of dinoflagellates was observed, reaching the level of subacute level in 50% of cases. The necessity of using several types of microalgae of different taxonomic affiliation when performing biotesting of sea waters is highlighted.