ГлавнаяENAquatic Bioresources & Environment. Volume 5, Number 3, 2022

Aquatic Bioresources & Environment. Volume 5, Number 3, 2022



Environmental Concerns and the State of Aquatic Environment

Pesticides of modern classes in the water and bottom sediments of Taganrog Bay
V. A. Valiullin, O. A. Zinchuk, Yu. E. Karpushina
Abstract. The rivers flowing into Taganrog   Bay   are almost entirely surrounded by   agricultural   land, where the use of chemical plant protection products is inevitable. This, in turn, leads to the ingress of active ingredients (AI) of pesticides into the water and bottom sediments of the water bodies of fisheries importance. In the water and bottom sediments of Taganrog Bay, the content of 20 active ingredients of the pesticides of modern classes most widely used in agriculture in the region, the half-life of which can exceed six months, has been   investigated using   high-performance   liquid chromatography   (HPLC). As   stipulated by the State Assignment, the research was being conducted throughout the year in 2014–2016 and in the spring and summer seasons in 2020. As a result of this investigation, such moderately toxic substances as clopyralid, pencycuron and tebuconazole have been identified as the main contributors to the pollution, while in 2014–2016, the main contaminant was low-toxic imidacloprid. In 2020, the total content of pesticide AIs has increased considerably both in terms of concentration and the number of substances found. However, the concentrations of pesticide AIs in the living environment of the hydrobionts in Taganrog Bay turned out to be lower than the established maximum allowable concentrations (MAC) developed for the water bodies of fisheries importance.
Keywords: pesticides, pesticide pollution, MAC, HPLC, active ingredients
Assessment of the pollution of the bottom sediments in the Azov sea by biotesting using bioluminescent tests
A. A. K. Al-Rammahi, M. A. Sazykina, T. O. Barabashin, Sh. K. Karchava, M. V. Klimova, M. I. Khammami, I. S. Sazykin
Abstract. This study is aimed at the toxicity assessment of the bottom sediments in the Azov Sea.
32 samples of the bottom sediments, taken in Taganrog Bay, as well as in the Northern, Western, Central, Southern, and Eastern regions of the sea, have been investigated. A biotesting method based on whole-cell bacterial lux-biosensors (Vibrio aquamarinus VKPM B-11245, E. coli MG1655 (pRecA-lux),
E. coli MG1655 (pKatG-lux), and E. coli MG1655 (pSoxS-lux)) was used to determine the toxicity level. Toxicity analysis of the Azov Sea bottom sediments showed their extensive contamination with pollutants of various nature. Integral toxicity was recorded for the surface sediments of all the investigated stations in the Azov Sea. The pollution level of the bottom sediments was estimated as highly toxic at 31 stations and as toxic at 1 station. The presence of genotoxic substances, both direct and promutagenic, was detected, as well as the presence of substances causing oxidative stress. It is shown that Taganrog Bay, the Central and Eastern regions of the Azov Sea are most exposed to pollution. The most polluted sampling stations for bottom sediments have been identified. Integral toxicity and the toxic effects caused by the presence of genotoxic and prooxidant substances indicate gradual accumulation of pollutants in the bottom sediments of the Azov Sea and its unfavorable environmental state. This study has established the biotesting method involving whole-cell bacterial luminescent sensors as a promising tool   for the   assessment   of the ecotoxicological state of the investigated water body. It is deemed necessary to put further efforts into the identification of toxically active compounds in marine sediments and exploration of their possible sources.
Keywords: Azov Sea, pollution, toxicity, lux-biosensors

Biology and Ecology of Aquatic Organisms

Content of trace elements in Zostera marina (Linnaeus, 1753) in the Northern Caspian Sea in 2018–2020
A. B. Imantaev
Abstract. This article presents a comparison of the content of heavy metals in Zostera marina in the Northern Caspian Sea for the autumn season (2018–2020). To determine the concentration of heavy metals (copper, zinc, manganese, lead, nickel, iron, chromium, cadmium), the method of atomic absorption spectrometry was used as prescribed in the state standard (GOST 30178-96). As   a result of this research, the data on the concentrations of trace elements have been collected, and the patterns of their accumulation in a plant organism have been identified. Decreasing series of concentrations of heavy metals by years have been compiled; the predominant trace elements (iron, manganese, zinc, copper) in the composition of Zostera marina have been identified, and their content has been analyzed. The biological absorption coefficients (BPC) for the investigated plant have been calculated based on the available data on their content in the soils of the Northern Caspian Sea. It is shown that Zostera marina can be used as a bioindicator for zinc and manganese in the Northern Caspian Sea, and the other heavy metals (copper, nickel, lead, iron, chromium, cadmium) are deconcentrators (BPC<1). A general decrease in the presence of heavy metals in Zostera marina in the Northern Caspian Sea has been recorded for the time range from 2018 to 2020.
Keywords: heavy metals, trace elements, concentration, Northern Caspian Sea, Zostera marina
Some aspects of the growing conditions of the Australian red-clawed crayfish (Cherax quadricarinatus) in the Astrakhan Region
O. V. Pyatikopova, B. M. Ankesheva, R. R. Tangatarova, I. N. Bedritskaya
Abstract. Traditional aquaculture is completely dependent on external conditions, such as the composition and quality of water, the content of oxygen dissolved in water, and the temperature, the annual course of which determines the duration of the cultivation period for crustaceans. This work is aimed to   determine the main hydrochemical conditions for the cultivation of the Australian red-clawed crayfish (Cherax quadricarinatus) (hereinafter ACCR) in the Astrakhan Region and compare the results with the composite indices of water quality at the farms for the cultivation of river crayfish and the established water quality standards for the water bodies of fishery importance. In the course of this work, the technological conditions for the cultivation of the Australian red-clawed crayfish were determined based on the main hydrochemical characteristics of the water in the Volga River, ponds, and recirculating aquaculture systems. To compare the main hydrochemical characteristics of water, the composite chemical indices of water quality at the farms for the cultivation of river crayfish and MAC (maximum allowable concentrations) are conventionally accepted as the operational standards. Based on the results of this investigation, the technological conditions and duration of cultivation of the Australian red-clawed crayfish in ponds and recirculating aquaculture systems have been determined for the Astrakhan Region. The limiting factor in this case is the water temperature, which limits the growing duration of tropical crayfish in its natural environment. When growing this species in a recirculating aquaculture system, in order to optimize the process, thе monitoring of hydrochemical parameters should be carried out and measures should be taken to reduce the concentration of nitrogen compounds (ammonium nitrogen and nitrites), the average values of which in the incoming water from a water source, the recicled water in a recirculating aquaculture system and the water in the ponds in use were higher than the optimal recommended values. The concentration of nitrates did not exceed the optimal value recommended for crayfish cultivation. Based on the results of this investigation, it was revealed that,   for the successful aquaculture of the Australian red-clawed crayfish in the Astrakhan Region, it is advisable to use the mixed cultivation method for this species (both in controlled conditions and ponds). The limiting factor at the stage of pond cultivation is the water temperature. The results of this study showed the need for additional investigation of the effect of nitrite nitrogen on the main physiological and length–weight characteristics of red-clawed crayfish and for finding the methods of controlling the content of nitrites in the growing environment of the Australian red-claw crayfish, namely recirculating aquaculture systems and ponds.
Keywords: aquaculture, Australian red-claw crayfish,   recirculating   aquaculture   system,   ponds,   water source, hydrochemical characteristics, recycled water, biofilter
Zooplankton of the lake part of the Mingachevir Reservoir and its Khanabad Gulf (Azerbaijan)
K. A. Taptygova
Abstract. This paper presents the results of zooplankton studies, conducted in the lake part of the Mingachevir Reservoir and in the Khanabad Gulf (Azerbaijan) in 2021. The taxonomic composition of the zooplankton community has been investigated, and 25 species and one subspecies have been identified. It has been found that all of them are typical species for the inland freshwater bodies of Azerbaijan, occurring both in mixohaline (brackish) and fresh waters. Ecological and zoogeographical characterization of the identified species is given, as well as their saprobity, and the seasonal dynamics of the community development is presented. The core of the community in terms of abundance and biomass was formed by cladocerans and copepods. In the lake part of the reservoir, the highest abundance was recorded in March and the highest biomass was recorded in June. In the Khanabad Gulf, the highest values of abundance and biomass were recorded in June. The Khanabad Gulf was characterized by the highest zooplankton productivity.
Keywords: Mingachevir Reservoir, the lake part, Khanabad Gulf, rotifers, cladocerans, copepods, species composition, abundance, biomass
Effect of the di(2-ethylhexyl)phthalate ester on the functional parameters of the hemolymph of the Mediterranean mussel (Mytilus galloprovincialis)
A. A. Tkachuk, M. S. Podolskaya, A. Yu. Andreeva, E. S. Kladchenko
Abstract. Di(2-ethylhexyl)phthalate (DEHP) is the most common phthalic acid ester used in plastic matter ubiquitously polluting the World Ocean. To date, the mechanisms of the toxic effect of plastic degradation products on aquatic living organisms have been poorly studied. In this work, we investigated the effect of DEHP at various concentrations (0.4 and 4.0 mg/L) on the hemolymph cellular composition and functional parameters of the hemocytes of the Mediterranean mussel (Mytilus galloprovincialis (Lamarck, 1819)). Hemolymph samples were taken following 24- and 48-hour incubation of the molluscs in the water containing different concentrations of DEHP. Changes in the cellular composition of the mussel hemolymph and in the levels of reactive oxygen species production by hemocytes have been analyzed using flow cytometry and light microscopy. After 24 hours of experimental exposure to DEHP, an increase in the granulocyte number (from 4.0±0.5 to 38.4±7.3 %) was already observed. Additionally, a decrease in intracellular levels of reactive oxygen species (ROS) in hemocytes was recorded, and the most considerable changes occurred at the lower concentration of DEHP (0.4 mg/L). The results of this study may be indicative of a toxic effect of DEHP on the immune functions of mussel hemolymph cells.
Keywords: di(2-ethylhexyl)phthalate,   Mediterranean mussel (Mytilus galloprovincialis), hemocytes, ROS
Bathymetric distribution of сommon mollusc species depending on the properties of soft substrates near the coast of the Western Crimea
A. N. Petrov
Abstract. Up   to the present   day,   the bathymetric distribution of   zoobenthos   under   hydrodynamic load and subordinate changes in grain size composition and density of bottom substrate have not been fully investigated. The objectives of this study are as follows: 1) to evaluate the density of bottom sediments at different depths off the coast of the Western Crimea; 2) to calculate the pressure force exerted on substrate by the common species of bivalve molluscs (Veneridae); 3) to reveal the reasons for the changes in mollusc species composition due to differences in the properties of bottom sediments in different locations. According to the   results of   the   underwater   studies, strongly   pronounced   storm-induced   re-sedimentation of sandy fractions is observed to the depth of 12–14 m. Sandy substrates with density of 4–8 conventional units (c. u.) are formed within this zone, and here prevails striped venus clam Chamelea gallina. These molluscs, characterized by a bulky shell (up to 30 mm) and high values of specific ground pressure (80– 90 mg/mm2), can dwell near the dense sandy surface, avoiding contact with the subsurface redox layer located 6–10 cm deeper. At the depth of 16–25 m, the effect of storm hydrodynamics on the bottom weakens and only sandy aleurite fractions with density of up to 2.5 c. u. are getting re-sedimented. Sediment redox conditions develop at the depth of 4–5 cm. Within this zone, the most abundant species is rough pitar venus Pitar rudis, represented by the individuals with shells up to 13 mm in length and specific ground pressure of 35–40 mg/mm2, which allows the molluscs to stay on   the surface of substrate and avoid the contact with the redox layer. At the depth of more than 27–30 m, during the storm-induced mixing processes, the sedimentation of small ground particles prevails over their horizontal transfer. In the grain size composition of the substrate, aleurite-pelitic fractions prevail, and redox layer develops deeper than 2.5 cm from the bottom surface. Only the thin surface layer consisting of loose silt with density of 0.8–1.0 c. u. remains suitable for habitation of macrozoobenthos; here, golden carpet shell Polititapes aureus, characterized by a thin shell and the lowest ground pressure (25–30 mg/mm2), prevails in terms of abundance. The results of this investigation can   facilitate the understanding of spatial   distribution patterns and   adaptive features of the most abundant macrobenthos species under the influence of key environmental factors.
Keywords: hydrodynamic load, substrate density, grain size composition, zonal communities of macrobenthos, venerid molluscs, bathymetric distribution, Black Sea

Ichthyofauna of Marine and Inland Water Bodies

Structure and status of the European anchovy (Engraulis encrasicolus L., 1758) population, wintering off the coast of Abkhazia, in the 2020/2021 fishing season
R. S. Dbar, P. D. Gamakharia
This paper presents the results of analytical processing of the data collected over the course of the 2020/2021 fishing season on the ecological structure and fishing biological parameters of the European anchovy (E. encrasicolus L., 1758), wintering in the coastal waters of Abkhazia. The dynamic parameters of the Azov and Black Sea stocks of the European anchovy have also been analyzed, and a comparative analysis of the main biometric parameters has been carried out. This work is aimed at the assessment of the state of migratory anchovy aggregations in winter based on the results of the 2020/2021 fishing season and identification of the changes in the main population parameters with application of the generally accepted ichthyological methods. Following the data on the anchovy catches for the investigated period, this paper presents the dynamics of the length–age catch composition and intra-annual patterns of the anchovy fishery for the both forms (Black Sea and Azov Sea). The changes in population characteristics as evidenced from the catch composition as compared to the previous years were recorded, as well as the spatial distribution of the anchovy aggregations wintering in the Abkhazian Black Sea. The monthly absolute values are given for the catch sizes, as well as their fluctuations. The results showing the main dynamic changes in the wintering aggregations of anchovy have been obtained; they characterized the status of the anchovy population as stable with a tendency for low biomass development. It provides the basis for a conclusion that an increase in fishing effort in the next 2–3 years is unacceptable.
Keywords: European anchovy, Azov and Black Sea form of anchovy, population and biological parameters, length–age composition, fishery dynamics, Abkhazia

Fisheries and Processing of Aquatic Bioresources

Technological standardization as a method of verification of catch volumes for sharks and rays in the Black and Azov Seas
L. M. Esina, L. A. Gorbenko
. In the fisheries industry, the output norms for the the products of aquatic bioresources processing are used to verify the actual catch volumes. Establishing of the scientifically substantiated coefficients of raw material consumption per unit of output is one of the key factors in resources exploitation. This work is aimed at technological standardization—establishment of the norms of wastes, losses and the output of processed products obtained from cartilaginous fish species caught in the Black Sea. This investigation has been targeting spiny dogfish Squalus acanthias, common stingray Dasyatis pastinaca, and thornback ray Raja clavata. Exsanguination of live cartilaginous fish immediately after it has been caught is a prerequisite of its processing. Following the research and testing on identification of wastes and losses during the processing of spiny dogfish and rays, the average output   values of   processed   fish have been   identified and the coefficients of raw material consumption have been calculated, which makes it possible, based on the volumes of processed and dressed product, to evaluate the volumes of caught cartilaginous fishes, which is especially crucial for the sharks   and stingrays, extremely sensitive to fishing   pressure.   In has been shown that the average output values for the spiny dogfish, dressed, gutted and headed, are 44.9 %. The output values for the split carcass (wings) of stingray and thornback ray slightly differ (50.4 and
51.8 %, respectively). Statistical processing of the output values for split carcasses of the rays has shown
their adherence to the law of normal distribution. Thus, it seems practical to establish a unified coefficient of raw material consumption for all rays (1.938), without the distinction between their species. The coefficient of raw material consumption for the production of gutted (exsanguinated) spiny dogfish was 1.454, and upon its further processing (beheading) it became 2.398.
Keywords: Squalus acanthias, Dasyatis pastinaca, Raja clavata,   spiny   dogfish,   common   stingray, thornback ray, technological standardization, catch verification, dressing, research and testing

Informational Messages

On the 100th Anniversary of the Southern Scientific Research Institute of Marine Fisheries and Oceanography (YugNIRO). Main milestones of the Institute’s growth and research in the Azov and Black Sea Basin and the World Ocean
A. K. Zaytsev, V. A. Shlyakhov, S. V. Vysochin, N. N. Kukharev, Yu. V. Korzun, L. M. Esina, A. M. Stafikopulo, A. A. Solodovnikov
. In dedication to the 100th Anniversary of the Azov-Black Sea Research Institute for Marine Fisheries and Oceanography (AzCherNIRO), its main historical milestones and research results have been presented. On March 13, 1921, under the aegis of the regional administration of “Glavryba” (Central Administration on Fishing and Fisheries Industry of the People’s Commissariat for Food), Kerch Ichthyological Laboratory was founded, which acquired the   status of an independent   organization in 1922 and became   the basis upon which AzCherNIRO was created in 1933, renamed into the Southern Scientific Research Institute of Marine Fisheries and Oceanography (YugNIRO) in 1988. Investigation of aquatic resources, started by the institute in the Kerch Strait, later covered the Azov Sea and the Northern and Eastern Black Sea; in 1957, they extended to ocean waters, with the Central Eastern Atlantic Ocean as their initial area. In 1960, the Ministry of Fisheries of the USSR appointed the Indian Ocean and Indian Sector of the Southern Ocean to AzCherNIRO as the survey areas in the World Ocean. From 1961 to 1990, in the course of hundreds scientific and exploratory expeditions to the Indian Ocean riparian waters, the researchers   and other employees of AzCherNIRO/YugNIRO and Yugrybpromrazvedka (South Fish Exploratory Service) for the first time discovered and contributed to the production sector the aggregation sites of tropical fish and invertebrates, deepwater species at underwater ridges, and stocks of notothens, ice fishes and krill in the Antarctic. In 1970–1980, the institute maintained laboratories on stock assessment of the Black Sea and oceanic fish species and invertebrates, on fish physiology and aquaculture, on processing technology for aquatic living   organisms, on   commercial   oceanology and industrial   fishing, and many others. Currently, the scope of the Kerch Department of the Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”) covers the research concerning bioresources of the Azov and Black Sea Basin, World Ocean and Antarctic, processing technologies and practices, development and improvement of fishing gear, hydrobiology and aquaculture, parasitology and commercial oceanology.
Keywords: anniversary, founding history, AzCherNIRO, YugNIRO, Azov Sea, Black Sea, World Ocean, biological resources, fisheries, processing technology, aquaculture