Aquatic Biocenoses Research Articles

СЦЕНАРНЫЙ ПРОГНОЗ РАЗВИТИЯ СЫРЬЕВОЙ БАЗЫ РЫБОЛОВСТВА И УЛОВОВ РЫБ В АЗОВСКОМ МОРЕ В УСЛОВИЯХ СОКРАЩЕНИЯ ОБЪЕМОВ ПРЕСНОВОДНОГО СТОКА И РОСТА СОЛЕНОСТИ

Background. The reduction in freshwater runoff and the increase in the Azov Sea salinity are accompanied by a drastic transformation of aquatic biocenoses, as well as restructuring of various ecological groups of the ichthyofauna. Abrupt changes in the composition and abundance of fishing targets render traditional approaches to fishing ineffective and dictate the need to develop new kinds of fishery. Relevance. Identification of possible scenarios of the fishery resource development for the next 5–10 years is necessary to ensure the fisheries sustainability in the Azov Sea Basin. The aim of this work is to analyze the dynamics of the composition of commercial fish catches in the Azov Sea in the modern period of the sea salinization and to develop possible status scenarios for the stocks and catches of fishing targets for the next 3–10 years to substantiate fisheries management and regulation. Methods. In the course of developing such scenarios, the data on the actual dynamics and trends in the fishery resource changes during the comparable periods have been used, as well as the data on the ecological valence of the representatives of various ecological groups of fish at different stages of their ontogenesis in terms of their salinity tolerance. Results. 3 main unequally probable scenarios of changes in the abundance and biomass of various ecological groups of fish — primary industrial-scale fishing targets in the Azov Sea — have been developed; the recommendations for adapting the existing fishing practices to the changes in the fishery resources have been given. Conclusion. A further decrease in the commercial importance is predicted for the freshwater fish species, freshwater-spawning anadromous and semi-anadromous fish species, as well as for gobies and Black and Caspian Sea sprat (tyulka). The role of Black Sea migrants — European anchovy, grey mullets, red mullet, Mediterranean horse mackerel, garfish — will be reduced. Marine fish species — acclimatized so-iuy mullet and Black Sea turbot (kalkan) — will become the main fishing targets.

LHYMO: A new Water Framework Directive‐compliant multimetric index to assess lake hydromorphology and its application to French lakes

Abstract Hydromorphology provides a physical framework for aquatic biocenoses. Its condition directly affects the quality of habitats available for fauna and flora, and its assessment is therefore useful for biodiversity and water quality conservation, as well as for restoration programmes required by European and national directives. In this study, a site‐specific index of Lake HYdroMOrphology, LHYMO, was developed to provide a quantitative assessment of the hydromorphological status of natural and non‐natural lakes that is consistent with European Committee for Standardization (CEN) standards and that can be used for different purposes, including the implementation of the Water Framework Directive (WFD) and of the Habitats Directive. This new LHYMO index includes nine metrics related to the morphological WFD quality elements (QEs) and six metrics related to the hydrological WFD QEs, all of which are considered to support biological elements. The reference conditions were defined for each metric using an original approach: the degree of alteration is measured in relation to the natural characteristics of each lake, relative to a state that ‘would be expected in the absence of disturbances’. Besides its use for regulatory purposes, this index is also a suitable tool for monitoring the efficacy of hydromorphological restoration projects or to help target effective conservation measures on lakes. Application of this index to 72 French lakes provides the first quantitative and homogeneous assessment of the hydromorphological quality of lakes over a whole territory and gives the first overview of the hydromorphological status of lakes in France, with classification into five classes ranging from ‘high’ to ‘bad’. LHYMO is already operational for large French lakes as it relies mostly on reference datasets available at a national scale, and it may also be used in a wider scope through gathering or completing data from other sources.

Проблема забруднення водних екосистем антибіотиками (огляд)

Purpose: To analyze and summarize information on the problem of contamination of aquatic ecosystems with antibiotics. Findings: The presented work describes global risks associated with the presence of antibiotics in the aquatic environment and aquatic organisms, and demonstrates quantitative and qualitative assessment of contamination with antibiotic residues in ocean aquatic resources using bivalves. Practical value. The review can be useful for the public engaged in ecology, agriculture, veterinary medicine, and fisheries; for experts in the field of pharmacology and microbiology. This paper can also be interesting for teachers and students of field-oriented universities. Keywords: Antibiotics, wastewater contamination with antibiotics, antibiotic resistance, stability genes, aquatic biocenoses, aquaculture, bivalve molluscs.

THE CURRENT STATE OF HYDROBIONTS OF THE AYDAR-ARNASAY SYSTEMS OF LAKES

The material for this article was the results of many years of comprehensive studies of the current state of the biodiversity of aquatic biocenoses (phyto- and zooplankton, periphyton communities and macrophyte associations, zoobenthic organisms and ichthyofauna), the taxonomic structure and species composition of hydrobions in the Aydar-Arnasay system of lakes. During the growing season (winter-autumn) of 2019-2020, from 186 to 224 species and forms of algae were found in phytoplankton samples, where the dominant complex is diatoms, blue-green and green algae. Zooplankton is represented by 67 species, of which Rotifera - 37 species, Copepoda - 17 species, Cladocera - 13 species. Periphyton is represented by three main groups: producers (308 species of forms and varieties of algae), consumers (21 species) and decomposers (8 species), a total of 337 organisms were noted. The ichthyofauna of the lakes is represented by 18 species and subspecies of fish, of which there are 18 species in the East Arnasay Lake, 16 species in the Tuzkan Lake and 14 species in the Aydarkul Lake.

The impact of iron coagulant on the behavior and biochemistry of freshwater mussels Anodonta cygnea and Unio tumidus during lake restoration

Iron (Fe) treatment is one of the most commonly used methods to restore eutrophic lakes and reservoirs. The Fe-based coagulants dosage results in an almost immediate improvement in water quality at a relatively low cost. However, the effects of the application of coagulants are not always predictable, and the scale of the risks is not fully understood. The dosage of coagulants changes the chemical and physical properties of water, thereby affecting aquatic biocenoses. In this study, several laboratory experiments were conducted to evaluate the effects of Fe-based coagulant dosage on two bivalves species: Anodonta anatina and Unio tumidus. Their ability to efficiently filter water and reduce seston makes them a key component of aquatic ecosystems in terms of maintaining proper ecological health and stable functioning. Behavioral response, biochemical parameters, and body chemistry changes in mussels exposed to different doses of coagulant were surveyed. A dose-dependent reduction in filtration activity of both species was observed. As early as 10g Fe m2 (which is a moderate dose used in lakes restoration), mussels of both species almost completely reduced their filtration activity and remained with closed valves for several subsequent days. Significant Fe accumulation in muscles of bivalves exposed to coagulant was also observed. This was particularly the case when very high doses of coagulant were applied. Then, the iron content in leg muscles of both species increased over fourfold. At the same time, a decrease in muscles calcium and phosphorus content was observed. No symptoms of oxidative stress (TBARS, H2O2) after mussels exposure to coagulants were found. The results suggest that the application of Fe-based coagulant for water ecosystem restoration may be a threat to the mussels population. These findings are significant for decisions on the selection of restoration methods for a specific lake.

Оценка влияния выращивания товарной рыбы в садках на экологическое состояние водоема

Growing a large mass of hydrobionts in a limited area (cage fish farming) entails a local increase in the load on the ecosystem from additional organic matter. In connection with the high growth rates of development of cage farms in various open natural water bodies, it is necessary to improve the system for monitoring their impact on aquatic biocenoses. The quality of surface waters and bottom sediments of the Ermakovskiy Bay of the Ust-Kamenogorsk Reservoir has been assessed in the of operation area of the cage farm Shygys, LLP. According to the zooplankton indices, the Pantle-Bukk saprobity index in the modification of Sladechek was used, the oligochaete index was used for macrozoobenthos. The studies were carried out at three stations: 200 m upper the bay (conditionally background station); at the cage line (reflects the local impact of the fish farm on the reservoir); 200 m lower the bay (reflects the overall impact of the enterprise on the reservoir associated with the removal of pollutants). As a result of the research, it was found that before the start 
 of cage fish farm operation the quality of water and bottom sediments at all points of the study corresponded to the “clean” category. A year after the launch of the enterprise a decrease in the taxonomic richness of zooplankton was noted, which indicates a slight deterioration in the quality of surface waters. In the fourth year of cage farm operation the saprobity indices near the cage line grew up to 1.8, and lower the bay - to 1.6, which indicates a local deterioration of the surface waters quality (class III, moderately polluted water). A similar situation is also characteristic of benthic communities of invertebrates. In 2017, at all three research stations, and in subsequent years only at a conditionally background station bottom sediments were characterized as clean. In 2019-2021 the pollution of bottom sediments was on the rise in the cage zone and below the Yermakovskiy Bay. The values of the oligochaete index increased from 14-20 to 58-75%. In 2019, bottom sediments were rated as class IV (contaminated), and in 2021 - as class V (dirty). On the results of the studies there were developed the corrective measures for reducing the anthropogenic load on the open natural reservoir. In the future monitoring the changes in qualitative and quantitative indicators of hydrobionts in the operation area of fish cage farms will allow local monitoring of water quality and timely adjustment of reclamation and fish breeding activities.

PHAGES OF BACTERIА OF THE GENUS BACILLUS ISOLATED FROM THE AQUATIC ENVIRONMENT

SummaryDespite the fact that bacteria of the genus Bacillus isolated from the soil have been studied for centuries, there are still topics that are not sufficiently covered or need further research. Most often, members of the genus Bacillus are isolated from soil or food. In recent years, these bacteria have begun to isolate from various aquatic biocenoses of ecosystems of oceans, seas, estuaries, lakes, rivers. Studies of such isolates indicate that bacteria of almost all species of the genus Bacillus are infected with bacteriophages of the order Caudovirales, which have caudal processes, integrase and excision systems necessary for the lysogenic development cycle. Although most of the bacteriophages found belong to the order Caudovirales, they have a wide range of differences, such as the relationship to temperature and pH, the impact on metabolism and sporulation of the host. The review presents data from the modern literature on bacteriophages that infect bacteria of the genus Bacillus isolated from aquatic biocenoses, features of their structure, chemical composition, genome structure and interaction with the host cell.

Assessing relationship of degradation of coastal zones and phytoplankton species structure of Lake Uvildy and Lake Turgoyak (South Ural, Russia)

The current paper aims at analyzing the species structure of the phytoplankton community of two reservoirs on the territory of South Ural. The given water bodies are of different trophicity, namely, oligotrophic Lake Turgoyak and oligomesotrophic Lake Uvildy. Both lakes, being natural monuments, are subject to intensive recreational use. A large flow of tourists is a serious problem for the ecological state of the water bodies coastal areas. Also, tourist activities can affect the state of aquatic biocenoses. In this work, the degree of recreational degression of the selected study sites was assessed. The analysis was carried out according to the state of landscapes, vegetation and trampledness of the surveyed area. Based upon the research the current paper reveals spatial patterns in the distribution of recreational load on the coastal geosystems and the level of anthropogenic transformation of the territory. Mainly due to the high density of recreational centres and camping areas, the coastal area is characterized by a high degree of regression. Some signs allow forecasting changes in the species composition of phytoplankton communities and the trophic status of the lakes depending on the degradation of the coastal zones. Diatoms (Bacillariophyta) have been dominant in plankton phytocoenosis of Turgoyak and Uvildy. At the same time, in the oligomesotrophic lake (Uvildy), the number of diatom species is significantly reduced in areas with a higher degree of regression. Thus, diatoms are sensitive indicators of anthropogenic impact on aquatic ecosystems. Green and blue-green algae biodiversity has grown in the water body. However, no relationship was found between their species diversity and the level regression. But the following tendency is observed for the oligotrophic Lake Turgoyak. The species diversity of green algae grows with an increase in the degression degree. To forecast the further state of the studied water bodies, the revealed patterns in the change of the phytoplankton species structure depending on the degradation level of the coastal territories can be used as eutrophication signs.

Environmental Рollution by Рharmaceuticals

The global use of pharmaceuticals is constantly growing and leads to water contamination with xenobiotic compounds with a wide range of biological activity. Most pharmaceutical products that are widely used in medicine and veterinary medicine are constantly discharged into domestic wastewater in unchanged form or as active metabolites. These medications include hormones, antibiotics, analgesics, antidepressants, and antitumor medications. Treatment plants are not able to effectively remove these compounds from wastewater, which contributes to their migration to freshwater ecosystems. With a long half-life, pharmaceuticals can accumulate in the environment, reaching biologically active levels. The presence of pharmaceuticals in aquatic ecosystems can lead to unpredictable environmental consequences and reactions and can also have a negative impact on human health. In the Russian scientific literature, very little attention is paid to the problem of environmental pollution by pharmaceuticals. Therefore, this review article discusses the main sources of pharmaceuticals and their metabolites, the fate of these compounds in the aquatic environment, their impact on human health and aquatic biocenoses.

Research of the Nutritional Value of Macrophytes of the Sea of Azov

The paper presents the results of research devoted to the nutritional value of macrophytes − green algae Ulvarigida C. Ag., Cladophora spp., red algae Callithamnion corymbosum (Smith) Lyngb. These typical representatives of the aquatic biocenoses of the coastal waters of the two seas, Cladophora spp., episodically dominate in the periphyton of the Sea of Azov. An analysis of the chemical composition made it possible to establish the predominance of the carbohydrate component (59.2 − 64.9 % absolute dry matter), the presence of pectin substances in significant quantities (% a.d.m.), namely in U. rigida − 12.1, Cladophora sp. − 7.5, C. corymbosum – 6.0. The amino acid composition of algae proteins was studied; limiting essential amino acids were established. In the mineral composition of macrophytes, the presence of phosphorus, calcium, potassium, sodium, magnesium was determined; a high iodine content was noted in U. rigida (4.3 – 4.6 %). All three types of algae belong to low-calorie raw materials (less than 90 kcal/100 g) and with a certain technological processing can be recommended in diets to reduce weight.

Assessment of prospects for the use of unicellular hydrobionts as test objects in the study of biotoxicity of ultradispersed metal particles

Active development of nanomaterials in various areas of human activity leads to their intensive release into the environment. Nanomaterials in aquatic ecosystems are of particular concern, leading to changes in water quality and dangerous for representatives of aquabiocenosis - aquatic invertebrates, bioaccumulating technogenic nanoparticles. In this regard, studies on the selection of an optimal test object from representatives of hydrobionts, having the most adequate response to various, including toxic, effects of nanomaterials, with further prospect of determining the potential risks that arise when they enter aquatic biocenoses are relevant. Cultures of freshwater ciliate of Stylonychia mytilus (wild strain) in the phase of exponential growth and Paramecium caudatum were selected as the objects of the study. Survival was a determined parameter. 9 laboratory preparations of ultradispersed particles of metals (zinc, copper, ferrum, argentum, cobalt, titanium, aluminum, molybdenum, nickel) were used in studies. The analysis of the effects of ultradispersed metal particles revealed a negative biological effect on Paramecium caudatum and Stylonychia mytilus. Paramecium caudatum was the most sensitive to increasing concentrations of nanoparticles, as evidenced by the death of individuals after 10 minutes of contact. In turn, the death of Stylonychia mytilus was observed only at the 60th minute of exposure. Based on the above, Paramecium caudatum culture can be proposed as an express test object, giving a response at the 10th minute of the experiment. For studies assessing various types of toxicity that require a longer contact time, Stylonychia mytilus is a more suitable test object, since the effect of nanoparticles on the cell can be observed for 60-180 minutes or more.

Ecological state of aquatic biocenoses in the streams of the Kola basin, Barents Sea

The ecological state of freshwater ecosystems is essential because they are actively used in human economic activities. As the habitats of valuable commercial fish species deteriorate, their population decreases rapidly. Therefore, environmental monitoring of water bodies, markedly affected by human activities, contributes to efficient natural resources management. Thus, analysis of recent data on the state of river ecosystems in the Kola Bay basin is of great interest. It shows the current state of biocenoses in some of the streams flowing into Kola Bay of the Barents Sea, an environmentally unsafe area on the Kola Peninsula. Studies have shown that in spite of ongoing human activities in the Kola Bay watershed, the state of the ecosystems in local streams generally remains satisfactory. The distribution density of Atlantic salmon juveniles in the tributaries of the Nizhnetulomsky Reservoir varies from 20 to 70 juv./100 m2. The distribution indices of trout in the River Bolshaya Lavna vary from 5 to 65 fish/100 m2 and those in streams from 10 fish/100 m2 (Goryachev Brook) to 18 fish/100 m2 (Tretiy Brook). The main factor which negatively affects the reproduction of diadromous fish species is hydrolic construction which results in the decrease of the Atlantic salmon, sea trout and whitefish stock. To efficiently maintain the ecosystems of the streams, the construction of fish-screening structures, the river channels should be recultivated and the artificial reproduction of valuable fish species should be launched.

Fate and effects of nonylphenol in the filamentous fungus Penicillium expansum isolated from the bottom sediments of the Gulf of Finland

Abstract Nonylphenol (NP) is the most abundant environmental pollutant that is classified as an endocrine disruptor, and it originates from the degradation of nonylphenol ethoxylates, which are widely used as industrial surfactants. It has been referred to in a list of substances of particular risk to the Baltic Sea, in a list of priority hazardous substances in the Water Frame Directive, and in the 3rd draft Working Document on Sludge, developed by the EU. In this study, the fate and effects of NP in the filamentous fungus Penicillium expansum isolated from the bottom sediments of the coastal zone of the eastern Gulf of Finland were investigated in laboratory experiments. This strain was more tolerant to technical nonylphenol (tNP) compared to other types of aquatic organisms, such as fish, protozoa, and algae. The toxicity concentration values of tNP in Penicillium expansum were EC 50 20 mg L − 1 and ЕС 90 > 100 mg L − 1 . The activity level of hydrolytic enzymes, cellulases and amylases decreased significantly in the tNP treatments. Given the significant role played by terrestrial fungi in the transformation of organic substrate into bottom sediment, such an effect from tNP on fungi could disturb the regulatory mechanisms and balance between the biosynthesis and biodegradation of organic matter in aquatic ecosystems as well as the formation of cenotic relations in aquatic biocenoses. Oxidative stress induced by tNP has been found to increase the synthesis of enzymatic protection factors, such as superoxide dismutase, catalase and nonenzymatic factors (melanin-like pigments and extracellular polysaccharides). This research indicated that the malondialdehyde concentration (the biochemical marker of lipid peroxidation) in the cells of the fungus decreased with increasing antioxidation factors. Penicillium expansum was able to decrease the tNP concentration in the culture medium. The removal of tNP was mainly caused by fungal degradation rather than by simple sorption and accumulation in the cells. Because terrestrial fungi play a significant role in the function of the heterotrophic block of bottom sediments and because tNP has become an increasingly persistent toxic organic and endocrine disruptor, these results may be ecologically relevant for aquatic systems. The results from this study demonstrate a potential application of this fungal species for the removal of tNP from the environment.

An update to modern taxonomy (2011) of freshwater planktic heterocytous cyanobacteria

It is essential for the modern taxonomic classification of cyanobacteria to be continually updated in accordance with revisions based on molecular sequence comparisons and combined with morphological features, ecophysiological characters and other biochemical and molecular markers (“polyphasic approach”). Several genera, which are characterized by their planktic life form and contain indicator species important for the evaluation of aquatic biocenoses in majority of water bodies are recognized in the monophyletic group of heterocytous cyanobacteria. Current taxonomic revisions (and nomenclatoric consequences) of the specific contents of these heterocytous cyanobacterial generic units are covered by this article. Among these genera, 12 contain only planktic species, three remaining genera contain both planktic and non-planktic species. Comments and suggestions for future research are stressed especially in the ecologically distinct genera, which includes species dominating in the plankton of various reservoir types.

Antilysozyme Activity as a Factor of Algae Survival in Aquatic Biocenoses

Field and laboratory investigations were performed to study the distribution and functional significance of antilysozyme activity (ALA) in algal cultures. According to the results obtained, ALA as a trait is widespread among green and blue-green algae but is expressed to different extents. Experiments on the algae–zooplankters model showed that ALA is a factor facilitating the survival of algae in freshwater communities by promoting the establishment of their trophic and symbiotic relationships with other aquatic organisms. Analyzing the intrapopulation structure of algal cultures associated with zooplankters, it was shown that changes in the ALA of algal clones have adaptive significance, providing for a greater stability of algal populations in biocenoses.

Investigation of Lysozyme–Antilysozyme Interactions in a Model Tetrahymena–EscherichiaCommunity

Lysozyme and antilysozyme activities present in a wide range of microorganisms determine the so-called lysozyme–antilysozyme system of hydrobionts, which greatly contribute to the formation of aquatic biocenoses. However, the mechanism of the functioning of this system in natural freshwater communities remains obscure. The experimental investigation of lysozyme–antilysozyme interactions in a model Tetrahymena–Escherichiacommunity showed that the antilysozyme activity of Escherichia colileads to incomplete phagocytosis, thus enhancing bacterial survival in a mixed culture with infusoria. The selection and reproduction of bacterial cells resistant to grazing by infusoria determine the character of host–parasite interactions and allow bacteria to survive. It was demonstrated that the antilysozyme activity of microorganisms, which is responsible for bacterial persistency in natural biocenoses, is involved in the maintenance of protozoa–bacteria communities in bodies of water.

Changes of toxicological properties of biodegradation products of anthracene and phenanthrene

The aim of this work was to determine toxicity and mutagenicity of anthracene and phenanthrene and their microbial biotransformation products. The following representatives of different trophic levels of aquatic biocenoses were selected for the toxicological tests: Selenastrum capricornutum, Lemna minor, Daphnia magna and Lebistes reticulatus. Mutagenic properties were determined by Ames test. Results of the analyses confirmed toxicity of studied PAHs for test organisms. Metabolites produced during biological degradation of anthracene and phenanthrene were also harmful for selected representatives of aquatic ecosystems.

Ecotoxicological relevance of atrazine in aquatic systems

AbstractIn this report an attempt is made to outline the ecotoxicological role of atrazine in aquatic ecosystems. A brief discussion of the chemistry and metabolism of atrazine is followed by a discussion of the occurrence of this herbicide in the environment. Peak levels for occurrence of atrazine in surface water range from up to 90 μg/L for flowing water to 2 μg/L for standing water. In reality, most values are significantly lower. As with ground water, in which atrazine has also been detected, great caution must be taken when interpreting data on the presence of atrazine in the environment. Atrazine is taken up by nearly all members of the aquatic biocenoses, but in many cases it is also quickly eliminated. The importance of these processes is discussed. The ecotoxicological effects of atrazine on producers, consumers, and decomposers as well as on ecosystem functions first become observable at levels of 20 μg/L or more; the changes are not lasting, even when studied over long periods. Indirect effects are also taken into account in the definition of the threshold value. Deviations from the ecotoxicological threshold value indicated by higher or lower toxi‐cological threshold values in the case of individual organisms are also evaluated. Furthermore, the threshold value is compared with the environmental concern level (EEC) of atrazine. The final assessment is that although atrazine may be potentially hazardous to the environment, the level of hazard depends on the concentration and degree of exposure. It can be assumed that at concentrations of up to 20 μg/L, atrazine does not cause any permanent damage to aquatic ecosystems.

Chromium(III) and Chromium(VI) Circulation in Aquatic Biocenoses

AbstractThe cumulation of chromium(III) and (VI) has been studied in batch cultures of planktonic algae Microcystis incerta, Scedenesmus obliquus, Chlorella kessleri and Chlamydomonas geitleri at different chromium and algal cells concentrations. It has been found that chromium(VI) is practically not cumulated in algae, whereas chromium(III) is very rapidly cumulated in all types of algae investigated. The cumulation factor increases with the decrease of the radius of algae cells and it reaches the value of 106 for Microcystis incerta even after a few hours of contact. The kinetics, the cumulation factors and the capacity of algae to cumulate chromium(III) is practically the same for living as well as for dead cells and therefore it can be concluded that the cumulation of chromium(III) is due predominantly to the chemical sorption on the surface of algal cells.

Some Problems in the Biogeography of Land Areas

Neglected research areas in biogeography are suggested. Biocenoses, or biotic communities, are the basic units with which the biogeographer should be concerned. Biogeographic research should now pass on from the study of species to integrated work on entire biocenoses, the interdependence between biocenoses and their biotopes, and the study of biocenoses in their comparative geographical context. Biogeography should be concerned with the structural features of biocenoses and their changes through time and through space. Of particular importance at the present time is the geographical aspect of man's influence on biocenoses. The discussion is limited to terrestrial biocenoses because, in the author's judgment, this aspect of biogeography has been lagging behind research on aquatic biocenoses.