编号 4 (2023)

The Anapa Barrier Beach is a large Holocene coastal accumulative form formed by sediments of terrigenous and marine origin in the north-western Caucasian coast of the Black Sea. In recent decades, the barrier beach shoreline has been retreating. The main reason for the retreat is the natural processes that caused the shortage and redistribution of sediments in the lithodynamic system of the barrier beach. With the sea level rising, the coast retreat may accelerate, and in the future, it may lead to degradation of the entire geosystem of the Anapa Barrier Beach. The paper aims to analyze and generalize information about the origin of the sediment material composing the accumulative body and the mechanisms of its redistribution in time and space, which is necessary for assessing the stability of the modern accumulative body. Based on a comprehensive analysis, which includes a number of paleogeographic, geomorphological, cartographic, granulometric, and mineralogical studies, several options for accumulating a large supply of sand were considered. It is shown that the development of the accumulative body of the Anapa Barrier Beach was determined by changes in the shore configuration, fluctuations in the sea level, as well as the direction and length of alongshore sediment flows. The Phanagorian regression interrupted the previous course of development of the accumulative geosystem of the Anapa Barrier Beach. The geosystem acquired its modern form during the Nymphean transgression. The accumulative body of the modern barrier beach was formed from the abrasion material of the indigenous shores of the Taman Peninsula and alluvium of the Kuban River. The alluvium came directly to the seashore during the Phanagorian regression.

The paper describes geoinformation software developed for automated formation of an array of input parameters necessary to assess the direction and relative intensity of alongshore sediment flows using the wind energy method. This method establishes a direct relationship between the energy of wind action on the water surface and the intensity of sediment movement. The method can be applied to calculations for shallow and relatively straight coastal sections with sand and gravel deposits. As input parameters, the software uses information about both the wind direction and speed, as well as the length of the wave acceleration along the sectors of different directions and the average depth along the acceleration rays. These parameters are individual for each segment of the approximation of the study coast section. The possibility of using wind data as the only parameter characterizing the driving force provides an advantage when using the method to conduct preliminary and reconnaissance assessments of the structure and main parameters of sediment movement in the areas that are poorly studied or not covered with disturbance data. The basics of the method were developed in the absence of computer technology. Therefore, the considerable complexity of preparing regional data limited the possibility to detail the coastline when approximating it by a piecewise linear function. The same limitation was imposed on the number of sectors in the wind direction when calculating the energy interpreted as a sediment movement force. The development and availability of modern geoinformation technologies in terms of creating new digital models of the bottom relief or using existing ones predetermined that the authors develop a modified version of the calculation scheme of the wind energy method and a specialized software tool to automate the preparation stage of a set of regional input parameters. The software allows the user to significantly accelerate preparation of digital data arrays to clarify the structure of sediment flows for extended sections of the coastal zone of Western Crimea.

The Black Sea, which is potentially the largest sink of CO₂ among the seas of the Atlantic Ocean, has been experiencing a decrease in pH over the last decades. Information on the acidification of the Black Sea and its impact on the marine biosystem is scarce. Based on literature and our own experimental data, we analyse the effect of low seawater pH values on the energy metabolism of the main commercial bivalve molluscs – the mussel Mytilus galloprovincialis and the oyster Magallana gigas. These species showed the ability to adapt energy metabolism levels over a wide pH range, from 7.0 to 8.1. When the pH was lowered by 0.1 unit, the oxygen consumption of mussels decreased on average by 10–20 % in the pH range 7.5–8.2. At pH 7.2–7.5, the respiration rate of M. galloprovincialis did not change and remained at 9.15–9.38 µg O₂/(g dry tissue·h) and then dropped to 6.8 µg O₂/(g dry tissue·h) at pH 7.0. In M. gigas, the oxygen consumption rate decreased uniformly: on average by 10–15 % for each 0.1 unit of pH change, up to pH value of 7.2. At pH 7.0–7.2, aerobic respiration of oysters was recorded at a minimum level of 4.6–4.8 µg O₂/(g dry tissue·h).

The paper uses the 2012–2020 joint oceanographic database of MHI RAS and SB FSBI SOI to estimate the self-purification capacity of Sevastopol Bay ecosystems in relation to biogenic nitrogen and phosphorus. The assimilation capacity and its specific value were calculated using the balance method. The paper estimates the average and maximum concentrations of inorganic phosphorus (PO₄) and nitrogen (NO₂, NO₃, NH₄), as well as the average and maximum rates and time of removal of these nutrients from the bay ecosystems. The paper shows changes in the percentage of forms of inorganic nitrogen (NO₂, NO₃, NH₄) in the water area of all parts of Sevastopol Bay for two periods (1998–2012 and 2012–2020). These changes had a greater impact on the content of the reduced form of ammonium nitrogen which has increased in all ecosystems of the bay in recent years. Changes in the self-purification capacity of the bay ecosystems were manifested as a spread of data on the assimilation capacity of the study ecosystems in relation to nutrients. At the same time, the lowest self-purification capacity was observed for the ecosystem of the eastern part of the bay. The paper assesses possible causes of the observed situation, which are associated with changes in the wind regime over the bay water area in the last decade and the resulting formation of the system of surface currents. The surface currents in the bay under prevailing easterly winds were calculated using the computational modeling method. The paper shows that an increase in the frequency of such winds contributes to increased ventilation of the waters of Yuzhnaya Bay and a more intense input of pollutants in the westerly direction. The paper analyzes the reasons for deterioration in the self-purification ability of the eastern part of the bay in the last decade in relation to all inorganic forms of nitrogen and phosphates. It was shown that changes in the self-purification ability of ecosystems throughout the Sevastopol Bay waters were associated with an increase in the recreational load on the bay coast.

The paper aims to assess the quality of ballast-water purification of phyto- and microzooplankton using various ballast-water treatment systems. The analysis of treatment systems performance was based on the results of the study of phyto- and microzooplankton taxonomic composition and abundance in 19 samples of ballast-water treatment after their treatment in the ships’ systems. The samples were taken onboard 12 oil tankers and 7 bulk carriers originating from the ports representing the Mediterranean basin, tropical West Africa and the NW Indian Ocean. The vessels entered the seaport of Novorossiysk for cargo loading from October 2022 to March 2023. In 90 % of all cases of the systems use, the ballast-water purification of unicellular organisms met the Regulation D-2 Ballast Water Performance Standard of the International Convention for the Control and Management of Ships’ Ballast Water and Sediments. The ballast of 10 % of the vessels (from Turkish ports in the Marmara and Aegean Seas) equipped with DESMI CompactClean СС-500 (treatment by filtration + UV) and Pureballast 3.2 1500 EX (treatment by UV system) did not meet the cleaning quality standard: 1.19·10⁶ and 1.21·10⁴ cells/L, respectively, were detected after treatment. The ballast waters of vessels from the Gulf of Suez and Mauritania represented a moderate risk in terms of cell abundance (7.16·10³ and 2.03·10³ cells/L, respectively). In total, 20 microalgal species were found: diatoms (13), dinoflagellates (6), a silicoflagellate (1), several algae taxa not identified to species, as well as ciliata. Proboscia alata and Prorocentrum micans were the most frequent. No planktonic algae classified as invasive to the Black Sea were found.