The studies of seasonal phytoplankton dynamics, its growth rate, and microzooplankton grazing were conducted on two stations in the western Black Sea coastal waters near Sevastopol from January 2021 to December 2022. The phytoplankton species composition has remained relatively the same during recent years compared to the end of the last century and the beginning of the 2000s. However, significant changes have occurred in the ratio between different species of diatoms, and the proportion of dinoflagellates was increased, especially in the autumn. Large diatoms and dinoflagellates play a crucial role in forming the phytoplankton biomass seasonal peaks. The first central maximum was observed in July, and the second smaller one was in September–November. Whereas two decades ago, the small diatoms generated three peaks annually: in February, May, and September–October. The maximum values of the phytoplankton growth rate and the rate of its consumption by microzooplankton decreased 2–3 times compared to the beginning of the 2000s. The relative share of primary production consumed by microzooplankton annually averages 35%, two times lower than before.

The duck mussel Anodonta anatina is widely distributed throughout the freshwater basins of Northern, Central, and Western Eurasia, and it has a comprehensive genetic structure. This study was devoted to the analysis of lineages, which are defined based on COI gene sequences. Our new dataset was expanded by samples from freshwater basins of Northern and Central Eurasia. It allowed us to reveal a high level of genetic diversity for the widely distributed trans-Eurasian lineage of A. anatina for the first time. As for results, representative samples from the Russian Plain, Southern Siberia, and the Ural region showed the presence of multiple interactions between duck mussel populations, indicating the existence of connections between freshwater basins in this region during the Late Quaternary. The genetic group from the freshwater basins of Northern Eurasia may be divided into two sub-lineages, which have differences in genetic structure and distribution patterns. It was revealed that there was a post-glacial expansion of duck mussels in the freshwater basins of Northern Eurasia after deglaciations of these territories and that the wide distribution of this species in this region was shaped via ancient connections between periglacial waterbodies. The lineage of A. anatina from the Ponto-Caspian region is a genetically rich and diverged group, which is present in the riverine basins of West-Central Asia related to the Caspian Sea.

The copper toxic effect was studied on two species of Black Sea diatoms Cerataulina pelagica and Phaeodactylum tricornutum, and two species of dinoflagellates Levanderina fissa and Prorocentrum nanum. A wide range of variability in the resistance of cultures to copper as a toxicant is demonstrated. The EC50 values for different species varied from 1.8 to 43.7 mg·L-1. An increase in the algae initial biomass within one species caused a corresponding decrease in the toxic effects of Cu2+. The two species of dinoflagellates with similar initial biomass and practically equal values of the specific growth rate, demonstrated significant difference in the EC50 parameter. In the small - celled species P. nanum it was equal to 43.7 mg·L-1, whereas, in the large species L. fissa, it decreased by almost 10 times. In the small-cell strain of the diatom C. pelagica, the semi-inhibition growth parameter was 13.5 mg·L-1, which is 2.4 times higher than in the large-cell strain with all other conditions being equal. The copper toxicological effect at low concentrations is determined, first of all, by a decrease in the electronic transport rate values (rETR) in cultures. The second parameter in terms of sensitivity to copper is Fv/Fm (maximum efficiency of photosystem II). The algae morphometric parameters are the most resistant to its impact: the volume and cell’s surface area, as well as the specific surface area. The significant changes on the third day of experiments were observed most often, at a copper concentration near EC50 or above.

Waste from limestone quarries is a product of primary industry and the extraction of building material, and their finely dispersed fraction often remains unclaimed and is stored. This causes environmental and economic problems, as these materials are easily dispersed by gravity, water, and wind. The purpose of this work is to substantiate an innovative method for the disposal of finely dispersed waste from open pits, including in the process of biological reclamation of the quarries themselves, based on the results of a study of the properties of these materials. In the course of the study, an experimental approach was used, which compared the results of growing plants on substrates: a pure finely dispersed fraction of waste, a mixture of a fine fraction and vermicompost, as well as pure vermicompost. Special attention was paid to the study of the effect of chlorella-based additives. The results of the study showed that the finely dispersed fraction of waste from limestone quarries can be successfully used in agricultural practice as a component of the substrate for growing plants, in combination with additives based on the culture of unicellular algae. Such a substrate has the necessary nutrients and stimulates plant growth. The findings could contribute to the development of a circular economy, in which waste from one process becomes resources for another, minimizing losses and reducing environmental impact. In particular, they serve as a substantiation of the scheme developed by the authors for closing technological cycles within the framework of the industrial symbiosis of economic entities of three different industries – a depleted limestone quarry, small farms and an enterprise that creates and operates a tourist facility as a result of reclamation and landscape rehabilitation of a depleted quarry.

The study assessed the ecological state of the marine environment in the Black Sea coastal zone on the territory of the popular Mayak public beach, located in the central part of Sochi and exposed to complex anthropogenic impact, using morphometric parameters of the Black Sea mussels Mytilus galloprovincialis L. as biomarkers. The studied parameters were compared with those of mollusks selected on a provisionally clean area of the Black Sea coast. In this paper morphometric parameters related to the size characteristics of the mussel shell — its length, width, and thickness — were used as the main biomarkers. On their basis we calculated two indices — the ratio of the shell height to its length (H/L) and the ratio of its width to its length (D/L) — which describe the relationship among morphometric parameters and determine the shell geometry formed under the impact of various environmental factors. As additional indicators, we recorded the colour, the characteristics of the mollusk shell surface, the sexual structure of the studied populations, and the ratio of the mussel raw body weight to the total weight of the mollusk with its shell. It was determined that the values of the main identified indices were significantly lower in the mussels from the clean zone, which can be explained by the fact that in the absence of negative effects mollusks do not need a strong and tightly closed shell to the same extent as animals from polluted areas. Moreover, the results revealed that the two studied mollusk populations from different habitat conditions demonstrated differences in practically all additional parameters. Thus, the studied biomarkers showing the state of biological communities in recreational zones indicate the presence of a systematic or repeated negative impact on marine aquatic organisms in the coastal waters of the Mayak public beach caused by anthropogenic activity. Произведена оценка экологической ситуации морской среды в прибрежной зоне Черного моря в районе наиболее популярного муниципального пляжа «Маяк», расположенного в центральной части города-курорта Сочи и подверженного комплексному антропогенному воздействию, с использованием в качестве биоиндикаторных признаков морфометрических параметров черноморских мидий Mytilus galloprovincialis L. Определяемые характеристики сравнивались с аналогичными показателями моллюсков, отобранных на условно чистом участке Черноморского побережья. В качестве основного биомаркера были использованы морфометрические параметры, связанные с размерными характеристиками раковины мидии: ее длиной, шириной и толщиной, на основе которых были рассчитаны индексы, характеризующие отношение морфометрических параметров друг к другу, что определяет геометрию раковины, формирующуюся под воздействием различных экологических факторов. В качестве подтверждающих показателей также фиксировались цвет, характер поверхности створки моллюсков, половая структура исследуемых популяций и соотношение сырого веса тела мидии по отношению к общему весу моллюска со створкой. Было выявлено, что величины определяемых индексов достоверно ниже у моллюсков чистой зоны, что определяется тем, что при отсутствии негативного воздействия моллюски не нуждаются в сильной и плотно закрывающейся раковине в той же степени, как животные из неблагополучных районов. Кроме того, обнаружено, что в двух изучаемых популяциях моллюсков, различающихся условиями сред обитания, имеются характерные различия по практически всем дополнительным исследуемым параметрам. Таким образом, используемые в данной работе биоиндикаторные характеристики состояния живых сообществ рекреационной зоны указывают на наличие систематического или повторяющегося негативного воздействия, обусловленного антропогенной активностью, на морских гидробионтах в прибрежной акватории муниципального пляжа «Маяк».

Цель - определение и анализ влияния основных геологических факторов, выявленных для исследуемой территории, на структуру и жизнедеятельность речных биоценозов на примере реки Мзымта. Материалы и методы. Исследование носит мультидисциплинарный характер и включает в себя методы геологии - при определении и систематизации опасных геологических процессов и факторов техногенеза на основе сбора, обобщения и анализа архивных, фондовых и публичных материалов геологических, геохимических, геофизических изысканий и рекогносцировочного обследования бассейна реки Мзымта, а также биологии - при определении воздействия этих факторов и их комплексов на сообщества гидробионтов в исследуемом водном объекте методами биоиндикации и биотестирования. Результаты и обсуждение. Идентифицированы три основные группы геологических факторов, оказывающих значительное негативное воздействие на биотопы водотока: экзогенные геологические процессы, локальные геохимические аномалии и техногенез. Анализ физико-химических показателей качества воды показал, что, в основном, негативное воздействие геологических процессов заключается в повышении концентраций взвешенных веществ, заиления донного субстрата и повышении содержания растворенных загрязнителей в речной воде, что приводит к нарушению структуры и деградации гидробиоценозов. Выводы. Использование биологических методов позволило выявить степень влияния идентифицированных геологических факторов на сообщества гидробионтов, а также установить наличие синергизма их воздействия на функционирование биологических систем...