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Over the entire period of studies in the water bodies in the Ural River basin, comprehensive hydrobiological studies have not been carried out in many areas both on the main watercourses of the Ural and Sakmara rivers and on a large number of tributaries of different levels. The results of such studies carried out by the Water Problems Institute, Russian Academy of Sciences, during expeditions in the summer and autumn 2022 are discussed. A large body of data on phytoplankton, zooplankton, zoobenthos, and juvenile fish was collected and processed. [ABSTRACT FROM AUTHOR]

High-frequency water quality measurements in streams and rivers have expanded in scope and sophistication during the last two decades. Existing technology allows in situ automated measurements of water quality constituents, including both solutes and particulates, at unprecedented frequencies from seconds to subdaily sampling intervals. This detailed chemical information can be combined with measurements of hydrological and biogeochemical processes, bringing new insights into the sources, transport pathways, and transformation processes of solutes and particulates in complex catchments and along the aquatic continuum. Here, we summarize established and emerging high-frequency water quality technologies, outline key high-frequency hydrochemical data sets, and review scientific advances in key focus areas enabled by the rapid development of high-frequency water quality measurements in streams and rivers. Finally, we discuss future directions and challenges for using high-frequency water quality measurements to bridge scientific and management gaps by promoting a holistic understanding of freshwater systems and catchment status, health, and function.

Copyright of Caldasia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background The Sustainable Development Goal (SDG) 14 addresses life below the waters, an important source of protein and contributor to global food security and economic development. Our aim was to explore possible evidence on the links between life below water and early childhood caries (ECC). Methods This scoping review identified articles on the link between life below water and caries according to the PRISMA-ScR guidelines. Three electronic databases (PubMed, Web of Science, and Scopus) were systematically searched in January 2023, using specific search terms. Studies written in English, with full text available, addressing life under water, focusing on dental caries in humans, with results that can be extrapolated to control ECC in children less than 6 years of age were included in the review. Descriptive statistics were used to summarize the retrieved papers and graphical presentation was used for visualization. Results There were 224 publications retrieved of which 13 studies, published between 1960 and 2022, were included in the analysis. The papers originated from Asia (7/13), North America (3/13), Europe (1/13), and 2/13 had multi-country authorship. Also, four laboratory studies extracted agents from marine products to determine their efficacy in preventing caries formation and preventing/slowing plaque formation; four letters discussed the caries prevention potential of sea salt as a source of fluoride; and two review articles about the positive effects of extracted marine products for caries prevention. Most (11/13) studies addressed target 14.1 concerned with enriching the marine environment with nutrients and minerals; two addressed target 14.4 focused on ensuring fish stocks are within biologically sustainable levels; two addressed target 14.7 aimed at increasing the economic benefits through sustainable use of marine resources such as fisheries; and one focused on target 14.5 aimed at conserving marine areas by increasing protected areas. In addition, one ecological study assessed the association between the ecosystem and ECC. Conclusions Currently, there is little known about the impact of protection of marine and coastal ecosystem from pollution and ocean acidification on the risk of ECC. Further evidence on possible associations between life below water and ECC management is needed.

Background: The Sustainable Development Goal (SDG) 14 addresses life below the waters, an important source of protein and contributor to global food security and economic development. Our aim was to explore possible evidence on the links between life below water and early childhood caries (ECC). Methods: This scoping review identified articles on the link between life below water and caries according to the PRISMA-ScR guidelines. Three electronic databases (PubMed, Web of Science, and Scopus) were systematically searched in January 2023, using specific search terms. Studies written in English, with full text available, addressing life under water, focusing on dental caries in humans, with results that can be extrapolated to control ECC in children less than 6 years of age were included in the review. Descriptive statistics were used to summarize the retrieved papers and graphical presentation was used for visualization. Results: There were 224 publications retrieved of which 13 studies, published between 1960 and 2022, were included in the analysis. The papers originated from Asia (7/13), North America (3/13), Europe (1/13), and 2/13 had multi-country authorship. Also, four laboratory studies extracted agents from marine products to determine their efficacy in preventing caries formation and preventing/slowing plaque formation; four letters discussed the caries prevention potential of sea salt as a source of fluoride; and two review articles about the positive effects of extracted marine products for caries prevention. Most (11/13) studies addressed target 14.1 concerned with enriching the marine environment with nutrients and minerals; two addressed target 14.4 focused on ensuring fish stocks are within biologically sustainable levels; two addressed target 14.7 aimed at increasing the economic benefits through sustainable use of marine resources such as fisheries; and one focused on target 14.5 aimed at conserving marine areas by increasing protected areas. In addition, one ecological study assessed the association between the ecosystem and ECC. Conclusions: Currently, there is little known about the impact of protection of marine and coastal ecosystem from pollution and ocean acidification on the risk of ECC. Further evidence on possible associations between life below water and ECC management is needed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The presence of pharmaceuticals in the aquatic environment presents a challenge to modern science. The most significant impact this can induce is the emergence of antibiotic resistance, which can lead to a global health emergency. It is important to note that the impact of pharmaceuticals in the aquatic environment is not limited to antibiotic resistance. Pharmaceuticals can also affect the behaviour and reproductive systems of aquatic organisms, with cascading effects on entire ecosystems. Numerous studies have reported the emergence of pharmaceuticals due to the uncontrolled disposal of polluted domestic, agricultural, and industrial wastewater in water bodies. This work discusses the potential of pharmaceuticals that on one hand are highly important for mankind, yet their non-judicious usage and disposal induce equally intriguing and problematic conditions to the health of aquatic systems. Pathways through which pharmaceutics can make their way into water bodies are discussed. Furthermore, the risk imposed by pharmaceuticals on aquatic life is also elaborated. The possible and pragmatic remediation methods through which pharmaceutical products can be treated are also discussed. Emphasis is placed on the potential of phytoremediation and advanced oxidative process, and the factors affecting the efficacy of these remediation methods are discussed.

Abstract Background Artificial habitats can allow many fish to flock together and interact and have been widely used to restore and protect fishery resources. The piece of research intends to elucidate the relationship of microbial communities between tilapia (Oreochromis mossambicus) intestines and artificial fishery habitats (water and sediments). Hence, 16 S rDNA sequencing technology was used to study the bacterial communities from intestines, water, and sediments. Results The results showed that the tilapia intestines had the lowest richness of Operational Taxonomic Units (OTUs) and the lowest diversity of the bacterial community compared to water and sediments. The intestine, water, and sediment microbial communities shared many OTUs. Overall, 663 shared OTUs were identified from the tilapia intestines (76.20%), the surrounding water (71.14%), and sediment (56.86%) in artificial habitats. However, there were unique OTUs that were detected in different sample types. There were 81, 77 and 112 unique OTUs observed in tilapia intestines, the surrounding water and sediment, respectively. Proteobacteria, Cyanobacteria, Actinobacteria, Firmicutes, Fusobacteria, and Bacteroidetes were the most common and dominant bacterial phyla between the tilapia intestines and habitats. In the two groups, the microbial communities were similar in the taxonomic composition but different in the abundance of bacterial phyla. Interestingly, Firmicutes increased, while Fusobacteria decreased in artificial habitats. These findings indicated that the artificial habitats had fewer effects on the water environment and indicated that the mode of artificial habitats could have an effect on the enriched bacteria in the tilapia intestines. Conclusions This study analysed the bacterial communities of artificial habitats from the intestines, water, and sediments, which can explain the relationship between the tilapia intestines and habitats and strengthen the value of ecological services provided by artificial habitats.

In the present work, we investigated the dynamics of the microbial communities in the wedge clam Donax trunculus (Linnaeus, 1758) from the Bulgarian coastal waters of the Black Sea. The samples were collected in the period of January 2020 until December 2022 from Arkutino, Ahtopol, Obzor and Tsarevo. The BIOLOG system was used for microbiological determination. In our investigation were isolated the following microorganisms: Enterococcus cancerogenus, Enterococcus hirae, Escherichia vulneris, Citrobacter farmeri, Acinetobacter gyllenbergii, Enterococcus hirae, Escherichia vulneris, Enterobacter cloacae, Escherichia hermannii, Pseudomonas mendocina, Pseudomonas fulva, Pseudomonas alcaligenes, Pseudomonas putida, Acinetobacter johnsonii, Acinetobacter gyllenbergii, Enterococcus hirae, Escherichia vulneris, Enterococcus gallinarum, Citrobacter sedakii, Pseudomonas putida, Streptococcus lugdunensis, Enterococcus casseliflavus, Vibrio cincinnatiensis, Vibrio alginolyticus, Vibrio parahaemolyticus, Enterococcus hirae, Streptococcus aureus, Staphylococcus lugdunensis and Enterococcus casseliflavus. During the winter period, we detected the presence of Pseudomonas sp. - P. alcaligenes, P. putida, and A. gyllenbergii. In the autumn months we isolated C. sedakii, C. farmeri, A. gyllenbergii, A. johnsonii, P. fulva and E. casseliflavus. In the spring, E. cancerogenus, E. hirae and Pseudomonas mendocina were found. During the summer, the highest biodiversity of microorganisms - E. hirae, E. vulneris, E. cloacae, E. gallinarum, P. putida, V. cincinnatiensis, V. alginolyticus, V. parahaemolyticus, S. aureus, E. hermannii and S. lugdunensis were registered. Although our three-year research showed that some species are permanent and others are transient, we tend to accept the conclusion that there is only a transient microbiota in mussels and it changes depending on environmental conditions or is a result of pollution of the Black Sea. [ABSTRACT FROM AUTHOR]

Brief results of oceanological studies in the south-eastern Baltic Sea and Gulf of Finland on cruise 54 of the R/V Akademik Sergey Vavilov (2022) are presented. Hydrological, hydro- and geochemical, hydrobiological, geoecological, geological, and geophysical studies were carried out. New data on the state and dynamics of the Baltic Sea natural complexes under conditions of increasing anthropogenic pressure and climate change were obtained. [ABSTRACT FROM AUTHOR]

In the present study, we report on the Eurasian Ruffe (Gymnocephalus cernuus) in the Mandra Lake at City of Burgas. This is the only water basin in southeastern Bulgaria that is known to be inhabited by the species. The Eurasian Ruffe was detected in Mandra Lake for the first time in 1998; since then, there has been no information concerning the local population. We captured two adult G. cernuus in the winter of 2020 and propose these specimens represent a permanent viable population. In this study, we report the first specimens registered by professional biologists, thus confirming the data acquired by sports fishermen over the years. [ABSTRACT FROM AUTHOR]

The presence of pharmaceuticals in the aquatic environment presents a challenge to modern science. The most significant impact this can induce is the emergence of antibiotic resistance, which can lead to a global health emergency. It is important to note that the impact of pharmaceuticals in the aquatic environment is not limited to antibiotic resistance. Pharmaceuticals can also affect the behaviour and reproductive systems of aquatic organisms, with cascading effects on entire ecosystems. Numerous studies have reported the emergence of pharmaceuticals due to the uncontrolled disposal of polluted domestic, agricultural, and industrial wastewater in water bodies. This work discusses the potential of pharmaceuticals that on one hand are highly important for mankind, yet their non-judicious usage and disposal induce equally intriguing and problematic conditions to the health of aquatic systems. Pathways through which pharmaceutics can make their way into water bodies are discussed. Furthermore, the risk imposed by pharmaceuticals on aquatic life is also elaborated. The possible and pragmatic remediation methods through which pharmaceutical products can be treated are also discussed. Emphasis is placed on the potential of phytoremediation and advanced oxidative process, and the factors affecting the efficacy of these remediation methods are discussed. [ABSTRACT FROM AUTHOR]

Public data of applied studies in the recent decade and the theoretical base and functioning principles of aquatic ecosystems, including phytoplankton, were analyzed to study the effect of the active introduction of the method for correction of water bodies algacenoses (the so-called "algalization") with the use of introduction of a wide range of strains of chlorella algae. A review of the most widely known cases to rehabilitate problematic water bodies is given; errors, delusions, and deliberate distortions of facts by representatives of agricultural industry, promoting the idea of rehabilitation of water bodies by correction of natural algacenoses, are considered. [ABSTRACT FROM AUTHOR]

Phytoplankton constitutes one of the most important components of lentic freshwater ecosystems, due it represents the basal resource for the growth and survival of the other organisms associated with these ecosystems. In addition, it provides relevant information for the diagnosis of the state of conservation of a waterbody, due to its sensitivity to a wide range of stressors, reflected in variations in its composition and structure. Despite several studies on the richness and dynamics of phytoplankton in lentic systems of tropical zones, knowledge of shallow wetlands in lowland zones is scarce. In the present study, it was proposed to determine the composition and structure of phytoplankton and its relationship with physicochemical variables, in the El Silencio wetland (Tolima, Colombia), a shallow aquatic system (depth <1 m). Eight samplings were carried out during a hydrological cycle, collecting four samples in the limnetic zone with a plankton net (23 µm). The phytoplankton community was mainly composed of the phylum Euglenozoa (78,9 %), followed by Chlorophyta (17,5 %) and to a lesser percentage by the phyla Cyanobacteria (2 %), Bacillariophyta (0,92 %), and Charophyta (0,10 %). The physicochemical variables that most influenced the composition of the phytoplankton community were alkalinity and total phosphorus. Likewise, the dynamics of phytoplankton were influenced by climatic changes and precipitation levels. The presence and representativeness greater than 90 % of Lepocinclis, Actinastrum, Trachelomonas, Phacus, and Euglena was associated with a high degree of eutrophication in the wetland. [ABSTRACT FROM AUTHOR]

Brief results of comprehensive studies of the southeastern Baltic Sea on cruises 47–49 of the R/V Akademik Boris Petrov (2021–2022) are presented. Research methods included geophysics, geology, paleogeography, hydrology, hydro- and geochemistry, hydrobiology, and geoecology. New data on paleolandscapes and parameters of long-term monitoring of spatiotemporal changes in the abiotic and biotic components of the Baltic Sea ecosystem were obtained. [ABSTRACT FROM AUTHOR]

This essay surveys the situation of Italian women life scientists from the late nineteenth to the mid-twentieth century. It follows the path that took women from being an exceptional presence to becoming a common, yet not equal, presence in the Italian science departments. Very different proportions of women occupied the three ranks in the academic hierarchy—students, research staff and professors. From the late nineteenth century onwards, women started to enrol in Italian universities. Initially, the second most popular department among female students—outdone only by the humanities—was that of mathematics, physics and natural sciences. Concerning women among research staff, a brief statistical analysis reveals the growing proportion of the female workforce in academic institutions and brings into view poorly known female assistants and technicians. The most difficult career step for women was to gain a tenured university position. A comparison between bacteriologist Giuseppina Cattani’s ‘failure’ to gain such a position and the ultimately successful strategy of zoologist and limnologist Rina Monti, who became one of the very first female university professors in Europe, illustrates the opportunities as well as the obstacles women naturalists encountered on the way into the academia. These experiences and those of others show that well into the twentieth century the support of powerful male mentors continued to be indispensable for women scientists. Positions in peripheral institutes or specializations in emerging research fields, in particular hydrobiology, entomology and cytogenetics, provided opportunities for Italian women to work their way up to professorships. [ABSTRACT FROM AUTHOR]

More than 1000 thermal and mineral water springs with temperatures from 20°C to102°C occur in Turkey. Kangal Balikli Hot Spring is known as psoriasis treatment center is one of the most important among these springs. The main scope of this research was to determine geological, hydrogeological and biological properties and water chemistry of the psoriasis treatment center and the stream running alongside the thermal pools. The spring water is an isothermal-hypotonic and oligometalic mineral water, having average of electrical conductivity: 530 μS cm-1, temperature: 35°C, CO2 8.70 mg l-1, pH 7.30 and O2 4 mg l-1. Calcium, magnesium and bicarbonates are dominant. Neither the chemical figures nor the temperature (35±1°C) of the water shows seasonal change. There are two fish species, Garra rufa and Cyprinion macrostomus, that adapted living at 35°C water temperature. The mean fork length and body weight of the fish living in the psoriasis treatment center is significantly lower than those living at the stream. Some of the fish in the pools showed symptoms of illness such as exophthalmus, scale loose, skin ulceration, pale gills, and bloated appearance. Gut analysis revealed that both species have been feeding on algae, insect parts, fish scales, and debris. In most cases the guts of fish caught in the pools were either empty or had very little content in it. Zooplanktons had little species and were not recorded frequently.

The idea of an ecosystem is one of the central concepts of modern ecology. Analysis of the structure and dynamics of ecosystems should underlie the scientific development and planning of environmental protection measures. How did systemic concepts in ecology originate and emerge? Hydrobiological studies of continental water bodies, especially lakes, have played an important role on this path. Due to their relative isolation, it was the lakes that served as a kind of testing ground for the formation of holistic principles in ecology. Using the example of several significant dates in 2021, this article analyzes how this happened in our country. In connection with the 150th anniversary of S.A. Zernov, a major organizer and, in essence, the founder of hydrobiological science and education in Russia, his efforts to organize a comprehensive study of water bodies, in particular, research at a biological station on Glubokoe Lake, are described. Particular attention is paid to Zernov's disciple V.I. Zhadin, the author of one of the first systems of views on the biological productivity of water bodies. In addition, the concept of the biotic balance of water bodies, which was first proposed 75 years ago, in 1946, by G.G. Vinberg is considered. The study of the energy relations of organisms, which is the basis of this concept, is the cornerstone of modern ideas about the functioning of ecosystems. [ABSTRACT FROM AUTHOR]

In outer space, ultraviolet and cosmic radiation, a wide range of high and low temperatures, altered gravity, electromagnetic fields, the vacuum, and their combinations determine the damaging effect on living organisms and act as a barrier to their interplanetary propagation. At the same time, biological dormancy, known in a wide range of bacteria, fungi, animals, and plants, makes it possible to preserve the viability of their dormant stages under extreme conditions for a long time. Along with lower organisms, resting stages (propagules) of multicellular animals and plants were tested on the ISS from 2005 to 2016 to assess their ability to survive after long-term exposure to open space and space flight conditions. About one-third of the more than 40 species studied were dormant stages of aquatic organisms (Cyprinodontiformes fish eggs, daphnia ephippii, resting eggs of phyllopods and ostracods, and diapausing larvae of dipterans). The experiments were carried out within the framework of four research programs: (1) inside the ISS station (AKVARIUM program) with a limited set of studied species; (2) outside the station in outer space, but without exposure to ultraviolet radiation (BIORISK programs); (3) in modified space conditions simulating the surface of Mars (EXPOSE-R program); and (4) in ground-based experiments with laboratory assessment of the impact of space flight factors (such as neutron radiation) on resting stages. Fundamentally new data were obtained on the tolerance of resting stages of terrestrial organisms to space environment factors, which has changed the idea of the possibility of bringing terrestrial life forms by spacecraft and astronauts to other planets. [ABSTRACT FROM AUTHOR]

A bibliography of the Fertő/Neusiedler See and Hanság/Waasen research coordinated by the Danube-Research Institute between 1972 and 2017 is presented. The bibliography lists 198 publications on the Fertő/Neusiedler See region and 28 on the Hanság/Waasen and furthermore, detailes of 19 projec reports are presented. Alphabetic lists of authors with references to their contributions to the research of both regions were also compiled.

Jargon is the specialised vocabulary of any science: it allows the creation of new terms to define concepts and it removes ambiguity from scientific communication. Yet, it may also hinder understanding for a broader audience. Given that the Journal of Limnology has jargon in its title, we here investigate the impact of the term 'limnology' on the way limnologists work, publish their research, and attract the interest of other scientists. We do so by comparing scientometric features of papers published from 1965 to 2020 that used the term 'limnology' against papers on similar topics but that used the term 'lake ecology' or 'hydrobiology', and to the marine counterpart of papers that used the term 'oceanography'. We found that papers using the term limnology score worse than those of the other topics in terms of both publication output and scientific impact. Limnologists may need to use other terms in addition to 'limnology' to reach a broader scientific audience. [ABSTRACT FROM AUTHOR]

While largely studied because of their harmful effects on human health, there is growing appreciation that viruses are also important members of the animal holobiont. This review highlights recent findings on viruses associated with Hydra and related Cnidaria. These early evolutionary diverging animals not only select their bacterial communities but also select for viral communities in a species-specific manner. The majority of the viruses associating with these animals are bacteriophages. We demonstrate that the animal host and its virome have evolved into a homeostatic, symbiotic relationship and propose that viruses are an important part of the Hydra holobiont by controlling the species-specific microbiome. We conclude that beneficial virus-bacterial-host interactions should be considered as an integral part of animal development and evolution.

The structural and functional characteristics of zooplankton communities of two thermokarst lakes on Samoylov Island (Lena River delta, Yakutia) have been studied. A total of 76 taxa of hydrobionts have been found in the zooplankton community of the studied lakes. The taxonomic lists of the spring-summer zooplankton compositions have been provided. The complex of species determining the community structure has been defined. Rotifers determined the species diversity and zooplankton abundance in the lakes. The biomass values were defined by large copepods. Cold-water-dwelling northern species made the greatest contribution to the quantitative indicators of zooplankton. The seasonal dynamics of quantitative indicators of zooplankton has been analyzed. The current state of the lakes has been assessed using the saprobity index and species diversity.

Study of natural and anthropogenic processes in the southern seas of Russia is a priority task of the Southern scientific center of Russian Academy of Sciences. Annually for 15 years, the Southern scientific center of RAS carried out sea expeditions in the south of Russia. The year of 2017 was marked as a 10-year anniversary of the first expedition of the R/V Deneb in the Azov and Black seas. During a five-year period from 2012 to 2016, 36 complex expeditions in the Azov and Black seas were carried out by R/V Deneb; the oceanographic database was enriched with the data of 3500 oceanological stations, more than 11,000 samplings were done at more than 900 complex hydrobiological stations. The expeditionary materials enlarged the oceanographic database of the Southern scientific center: the field and archival data permitted to assess long-term dynamics of organic matter and carbon, the Azov Sea transparency and salinity and to calculate the characteristics of small-scale variability of temperature, salinity, internal waves and level fluctuations in the Azov and Black seas. The research in the Black Sea provided extensive synchronous data which characterize current state of the most vulnerable psammophilic benthic communities at the depths of 2–20 m. The estuaries of small rivers at their junction with the sea were studied in details. The new data on distribution and quantitative characteristics of jelly-like-, phyto- and pico-plankton over the whole shelf area of the Russian sector of the Black Sea is obtained. The Black Sea population of newcomers – Holland crabs (Rhitropanopaeus harrisi tridentate) – living exclusively in the sea canyons with unstable salinity was studied. The metagenomic approaches applied to study the plankton communities in the Azov and Black seas, were used to obtain new data on diversity and structure of marine bacterial communities. The oceanological observation data on the environment conditions in the Azov and Black seas are annually directed to the Hydrographic department of the Black Sea Navy of Russian Federation where it is used in the field service.

There is growing demand for biotechniques in oceanobiological and hydrobiological studies. Immunohistochemistry (IHC) combines anatomical, immunological and biochemical techniques to identify specific antigen-antibody interactions. Detecting the target antigen with labeled antibodies is a multi-step process that requires optimization at every level to maximize the signal detection. Here we use zebrafish samples and optimize each IHC step, particularly antigen retrieval, transgenic reporter double staining and background counterstaining. The resulting images with high signal intensity lead us to recommend the resulting protocols for experiments with fish.

The paper considers the qualitative characteristics (chemical composition of waters and sediments, biological diversity) of the Lena runoff and their transformation as a result of the biogeochemical pro-cesses taking place in the delta region. The hydrological, hydrochemical, geochemical (chemical com-position of river sediments), and hydrobiological description of the delta branches at the current stage has been provided. The Lena delta branches are characterized by a wide variety of water discharge values and hydro-dynamic conditions. It has been revealed that the hydrochemical composition of the delta is specific due to the dominance of hydrocarbonates and calcium ions, pH 6.9–7.9, high oxygen saturation conditions (more than 100 % sat.) throughout the water column because of wind activity, high concentrations of dissolved silica (1.1–2.7 mg/L) and iron (0.01–0.07 mg/L) if compared to the world’s mean values in natural freshwater bodies, and low concentrations of trace elements (mainly below the detection limits). The concentrations of nitrates and phosphates have been estimated in the range of 2.6–34.7 µg/L and 3.1–26.2 µg/L, respectively. The bottom and suspended sediments have been assigned to the siliceous type (Si/Al varies from 4.2 to 18 µg/L). The results of the analysis of hydrodynamic conditions, hydrobiological features, geochemical indi-ces, as well as data of the statistical factor analysis, have shown chemical elements redistribution dependencies. Several factors determining the chemical composition of water and sediments in the Lena River delta have been distinguished. The interpretation of these factors reflects the influence of river catchment area, cryogenic processes in the river delta, and biogeochemical processes. Based on the modern multidisciplinary research performed in the Lena delta, it has been demon-strated that processes leading to an inhomogeneous distribution of chemical elements between water (dissolved fraction), suspended matter, and bottom sediments occur in the delta of the river.

The blue green algae as photosynthetic organisms have a main effect on life and productivity of the aquatic ecosystems. Intensive and longtime studies on identification, distribution, and diversity of Cyanophyta have to be a crucial task in the Caspian Sea. Four transects were determined parallel to the Sabzehrud River, the Lavij River, the Noor River, and the Faculty of Marine Sciences of Tarbiat Modares University from 2014 to 2015. Samples were seasonally collected from three stations in each transect by a plankton net with a mesh size of 55 and the Ruthner's bathometer. Standard hydrobiological and phycology approaches were used for identification and counting abundance of Cyanophyta. The most number of Cyanophyta was observed 1.06 × 106 cells per liter at the station of A1 during summer. Genera such as Chroococcus, Gloeocapsa, Merismopedia, Microcystis belonged to unicellular taxa and Anabaena, Anabaenopsis, Nostoc, Oscillatoria, Phormidium were identified as multicellular genera. At the most stations, Anabaenopsis nadsonii was found as the most encountered species. Overall, Cyanophyta abundance was significantly different among stations in all investigated seasons. The blue green species also did not have same frequency distribution inside of the each transect (Test Chi-Square, P

The Baraba and Kulunda steppes are located in southwestern Siberia in an area with an arid continental climate. This paper presents results of the first study of the hypersaline Lake Krasnovishnevoye (Baraba steppe, TDS (total dissolved solids)=297 g/L, pH 7.88). The major chemical, mineralogical and biological features of the lake were studied and compared to those of Lake Malinovoe, a typical saline neutral lake of Kulunda steppe (TDS=396 g/L, pH 7.63). The phytoplankton composition and the culturable diversity of anoxygenic phototrophic bacteria from Lake Krasnovishnevoye correspond to the ones in the Kulunda lakes. Nevertheless, the peculiarities of water composition and regime of Lake Krasnovishnevoye reduce the biodiversity to prokaryotes and unicellular algae. [ABSTRACT FROM AUTHOR]

The current taxonomic composition, structure, and quantitative characteristics of zooplankton in channels of the mouth region of the Lena River were considered. The community of summer zooplankton in the Lena channels included 34 zooplanktonic species belonging to 18 families and 29 genera. Rotifers, as the most diverse and abundant group, provided a basis for the species diversity. It was found that the zooplanktonic community of the Lena channels is characterized by the low values of species diversity and quantitative characteristics.

This year an outstanding hydrobiologist, D. Sc. (Biol.), Professor, Chief Researcher of the Institute of Marine Biological Research RAS Oleg Mironov celebrates the anniversary. The impact of oil and oil products on mass species of marine organisms in the Black Sea was studied under his guidance for the first time. New data were obtained in expeditionary conditions: scientists have studied the patterns of distribution, the abundance, biochemical features and species composition of oil-oxidizing microorganisms in the Black, Red and Mediterranean seas, as well as in various regions of the Pacific, Indian and Atlantic oceans.

This year the famous marine ecologist, D. Sc. (Biol.), Professor, Chief Researcher, head of Marine Ecosystems Functioning Department of the Institute of Marine Biological Research RAS Ernest Samyshev celebrates the anniversary. The sphere of his scientific interests lies in ecology, hydrobiology, biocenology, the study of anthropogenic impact on aquatic ecosystems, fish and invertebrate mariculture, invertebrate products of the World Ocean.

There are some tools in place that classifies and/or rank beaches according to a series of parameters. It is possible to identify a gap in the development of tools that map and describe beaches without putting the results into a classification status of good or bad. Since beaches are important from different points of views such as ecology, tourism, economy, pollution or invasive species studies and management, fisheries, estate development, protected areas, among others it is relevant to describe and understand parameters in detail. This work offers a multi-purpose and interactive beach descriptor called BeachLog. It can be used by beachgoers to keep their own records in the same way a diver uses a Diver's LogBook, managers can use the tool to support coastal management projects, long-term monitoring, and beach description baseline. Also, BeachLog can be a didactic tool to aiming to bring environmental sciences closer to technology through the use of spreadsheets and dashboards. BeachLog is based on the more frequent parameters in the literature, selected, organized, accounted for, and altered/added according to expert opinion. We created a list of 28 parameters, all of which were described in details of what is expected to be observed by the user. They were divided into 5 groups (Environmental characteristics, Services & Infrastructure, Information & Security, Planning & Management, and Descriptive). Here, we describe 14 Brazilian beaches using the BeachLog by inputting the results as parameters presence or absence (0/1) and descriptives in a table that can be transformed into an interactive dashboard for better/easier visualization. Planning & Management was absent on all 14 beaches studied, pointing out the relevance and gaps in this group. In the other groups it was possible to observe variation in the parameter occurrence, indicating that each beach is different and it is important to observe parameters individually. Beach Litter and Invasive Species parameters from the Environmental characteristics group were present in all beaches. BeachLog showed as an easy way to describe a beach and can be a tool to support diagnosis and understanding of the beach's status., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Bruna de Ramos reports financial support was provided by Coordination of Higher Education Personnel Improvement., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Owing to a long history of anthropogenic pressures, freshwater ecosystems are among the most vulnerable to biodiversity loss 1 . Mitigation measures, including wastewater treatment and hydromorphological restoration, have aimed to improve environmental quality and foster the recovery of freshwater biodiversity 2 . Here, using 1,816 time series of freshwater invertebrate communities collected across 22 European countries between 1968 and 2020, we quantified temporal trends in taxonomic and functional diversity and their responses to environmental pressures and gradients. We observed overall increases in taxon richness (0.73% per year), functional richness (2.4% per year) and abundance (1.17% per year). However, these increases primarily occurred before the 2010s, and have since plateaued. Freshwater communities downstream of dams, urban areas and cropland were less likely to experience recovery. Communities at sites with faster rates of warming had fewer gains in taxon richness, functional richness and abundance. Although biodiversity gains in the 1990s and 2000s probably reflect the effectiveness of water-quality improvements and restoration projects, the decelerating trajectory in the 2010s suggests that the current measures offer diminishing returns. Given new and persistent pressures on freshwater ecosystems, including emerging pollutants, climate change and the spread of invasive species, we call for additional mitigation to revive the recovery of freshwater biodiversity., (© 2023. The Author(s).)

Euglenids are a diverse group of flagellates that inhabit most environments and exhibit many different nutritional modes. The most prominent euglenids are phototrophs, but phagotrophs constitute the majority of phylogenetic diversity of euglenids. They are pivotal to our understanding of euglenid evolution, yet we are only starting to understand relationships amongst phagotrophs, with the backbone of the tree being most elusive. Ploeotids make up most of this backbone diversity-yet despite their morphological similarities, SSU rDNA analyses and multigene analyses show that they are non-monophyletic. As more ploeotid diversity is sampled, known taxa have coalesced into some subgroups (e.g. Alistosa), but the relationships amongst these are not always supported and some taxa remain unsampled for multigene phylogenetics. Here, we used light microscopy and single-cell transcriptomics to characterize five ploeotid euglenids and place them into a multigene phylogenetic framework. Our analyses place Decastava in Alistosa; while Hemiolia branches with Liburna, establishing the novel clade Karavia. We describe Hemiolia limna, a freshwater-dwelling species in an otherwise marine clade. Intriguingly, two undescribed ploeotids are found to occupy pivotal positions in the tree: Chelandium granulatum nov. gen. nov. sp. branches as sister to Olkasia, and Gaulosia striata nov. gen. nov. sp. remains an orphan taxon., (© 2023 The Authors. Journal of Eukaryotic Microbiology published by Wiley Periodicals LLC on behalf of International Society of Protistologists.)

General principles of the theory of polyfunctional role of biota in self-purification of water in aquatic ecosystems have been formulated. The theory includes the following elements: (1) energy sources for self-purification of aquatic ecosystems; (2) main functional units of the self-purification system; (3) main selfpurification processes; (4) contributions of major taxa to self-purification of aquatic ecosystems; (5) reliability of the system and mechanisms ensuring it; (6) self-regulation of biota; (7) response of the system to external stimuli (impacts); (8) analogy between an ecosystem and a bioreactor; (9) conclusions for nature conservation practice. The theory covers both freshwater and marine ecosystems. [ABSTRACT FROM AUTHOR]