Investigated Water Bodies Research Articles

Gender-specific responses in gene expression of Nile tilapia (Oreochromis niloticus) to heavy metal pollution in different aquatic habitats

Monitoring heavy metal accumulation is essential for assessing the viability of aquatic ecosystems. Our methodology involved integrating analysis of immunological, stress, inflammatory, and growth-related gene expression in male and female Nile tilapia with on-site recordings of physicochemical parameters. Additionally, we assessed the effect of different physicochemical parameters on heavy metal bioavailability and residual concentration in fish and water. Samples of fish and water were gathered from three different localities: Lake Brullus, a brackish lake sited in northern Egypt; Lake Nasser, an artificial freshwater reservoir located in southern Egypt; and El-Qanater El-Khayria, a middle-freshwater location belonging to the Rashid branch of the river Nile. The assessment of heavy metal residues (Fe, Cu, Zn, Mn, and Ni) revealed that their concentrations were higher in fish specimens compared to their counterparts in water (except for Ni). In addition, Lake Brullus emerges as the most polluted area, exhibiting elevated levels of heavy metals concentrations in water and fish specimens. In contrast, Lake Nasser showed the least degree of heavy metals pollution. Gene expression analysis revealed gender-specific responses to heavy metal exposure at the three investigated water bodies. The expression of hepatic antioxidant genes (GST and MT) and inflammatory-related genes (CC-chemokine and TNFα) increased in males compared to females. In females, the immune and pro-inflammatory-related genes (IgM and CXC2-chemokine) transcripts were upregulated. Additionally, growth-related genes were downregulated in both Lake Brullus and El-Qanater; on the contrary, fish samples from Lake Nasser exhibited a normal expression pattern of growth-related genes. Stress-related genes (HSP70 and HSP27) showed significant downregulation in gills of both genders from Lake Brullus. The minimal presence of heavy metal contaminants in Lake Nasser seems to endorse the normal patterns of gene expression across all gene categories. A potential gender-specific gene expression response towards pollution was noticed in genes associated with inflammation and antioxidant activities. This highlights the importance of considering gender-related responses in future environmental assessments.

Unveiling the Dynamics of Cryptosporidium in Urban Surface Water: A Quantitative Microbial Risk Assessment and Insights into Climatic and Seasonal Influences

In response to global urbanization and economic development, urban surface water pollution has become a universal challenge and particularly affects densely populated megacities, and Dhaka is no exception. The discharge of 98% of untreated domestic sewage and massive volumes of industrial wastewater from over 7000 industries escalate surface water crises. This study investigates microbial and fecal contamination with particular emphasis on Cryptosporidium in surface water, known for causing waterborne diseases, such as cryptosporidiosis. Findings reveal high Cryptosporidium oocyst concentrations and fecal contamination in various water bodies in Dhaka City. Among the investigated water bodies, the Buriganga River exhibits the highest Cryptosporidium oocyst concentration (46%), while the Balu River, Turag River, Shitalakkhya River, Dhanmondi Lake, Gulshan Lake, Banani Lake, Ramna Lake, and Crescent Lake also present high levels of oocyst concentrations ranging from 21–40%. This study also calculated infection risks and found that the infection risk of swimming is highest during the wet season and is (3.9 ± 2.2 (95% CI: 3.0–5.0)) × 10−2 per swimming event, whereas it is approximately (2.4 ± 1.9 (95% CI: 1.6–3.3)) × 10−2 during the dry season. Annual diving risks are approximately (1.2 ± 0.6 (95% CI: 0.9–1.4)) × 10−2, indicating considerably high risks. Most of the sampling sites generally show significantly higher risks than other study areas like the Mymensingh and Kushtia Districts. In light of these results, we strongly recommend immediate measures to address water quality issues and mitigate the risks associated with Cryptosporidium contamination in Dhaka’s surface water.

НОВЫЕ НАХОДКИ МЕДИЦИНСКОЙ ПИЯВКИ HIRUDO VERBANA (CARENA, 1820) В ВОДНЫХ ЭКОСИСТЕМАХ КАБАРДИНО-БАЛКАРИИ

Background. Medicinal leeches are a traditional aquatic biological resource in Russia, officially used in practical medicine, pharmacology and cosmetology. However, in recent decades, the distribution range and abundance of these valuable aquatic organisms on the Russian territiry have decreased considerably. Relevance. The study of the present geographical range of this exploitable leech species is of practical importance, since the modern technology of their controlled breeding at biological production facilities requires constant replenishment of the broodstock and procurement of mature individuals from natural populations. This work is aimed at the identification of the current habitats of medicinal leeches in the aquatic ecosystems of the Kabardino-Balkarian Republic. Methods. This research was carried out in the last ten days of August 2021 in the daytime, in the littoral part of the water bodies of the plain and foothill zones of Kabardino-Balkaria. Leeches were caught with a handheld net, as well as collected manually from the objects in the immediate surroundings. The species of the caught leeches were determined using taxonomic keys in accordance with the modern classification. Results. New data on the distribution of the exploitable species of medicinal leeches Hirudo verbana (Carena, 1820) in the aquatic ecosystems of Kabardino-Balkaria are presented. Habitats of natural populations of this leech species were found in the Trek Lake and Deya River. Conclusion. The presence of the medicinal leech H. verbana in the investigated water bodies indicates their good ecological state. The results of this study make it possible to expand our understanding of the present distribution range of this exploitable species of aquatic organisms.

Microphytobenthos of Water Bodies of Some Islands of the Indian Ocean

Microphytobenthos of water bodies of some Maldivian Islands (Kelaa and Filladho) and the Madagascar Island of the Indian Ocean was studied in autumn (September and November) 1981. As a result of the performed investigations, 43 species of microscopic algae belonging to 30 genera, 25 families, 21 orders, 5 classes, 3 divisions, 2 kingdoms, and 2 empires (domains) were found. Among them, diatoms (38 species) prevailed over Dinoflagellata (4) and Cyanobacteria (1). The Sorensen - Chekanovsky coefficient of community similarity between the Maldivian and Madagascar floras was 0.56 and the Jaccard coefficient of community similarity was 0.36. Microphytobenthos of the investigated water bodies was of marine type. It was represented by alkaliphilous species and cosmopolitan (27 species) and tropical (10) groups with boreal-tropical (4) and boreal-tropical-notal (2) elements.

European research project on the state of pollution in the Black Sea «Black Sea SIERRA»: mission and partic ipation of Ukrainian oceanographers

The destruction of civil and industrial objects in Ukraine caused by a decade-long armed conflict, especially since February 2022, has led to extensive environmental pollution within the country, particularly in the waterways of the Black Sea basin.
 The consequences of these actions have also affected the state of the Black Sea, causing concern for the European Union and the global scientific community. Therefore, within the framework of the European program «Horizon Europe», funds were allocated for scientific research into the consequences of pollution in coastal water bodies and the Black Sea as a whole. In the 2023 «Horizon Europe» project competition, a proposal by an intergovernmental consortium of 7 scientific organizations from 5 countries was awarded the grant, including the State Institution «Scientific Hydrophysical Center of the National Academy of Sciences of Ukraine».
 The project aims to create effective monitoring and quality control strategies for water, as well as the implementation of innovative technologies to reduce the impact of pollutants on the ecosystems of the Black Sea. The application of research results is planned for the development of environmentally sound recommendations and strategies for the conservation of the marine environment. The project involves collaboration between countries to address pollution issues and study the Black Sea, as well as the development of scientific approaches to water resource management in the region. Special attention is given to the development of educational programs regarding the impact of military pollution on the water ecosystems of the Black Sea region.
 This article describes the localization, factors, and types of pollution in waterways and the Black Sea basin, the project’s structure, types of activities, and the investigated water bodies in Ukraine, as well as the participation of SI «Scientific Hydrophysical Center of NAS of Ukraine» as a project participant.

ЕКОЛОГО-ФАУНІСТИЧНІ ОСОБЛИВОСТІ УГРУПОВАНЬ ЗООПЛАНКТОНУ, ІХТІОФАУНИ У РІЧЦІ ІРПІНЬ

B a c k g r o u n d . Monitoring of ecosystems affected by military actions is an element of a comprehensive assessment of the state of the ecosystem in the post-war period. The results of this study are key for the post-war recovery of the war-affected region and assessment of the state and quality of water resources in the area for their further use, as well as for the assessment of the consequences of Russian armed aggression for local water ecosystems and the hydrological network of the region in general. In February-March 2022, the Kozarovytska dam was blown up, which caused flooding of the floodplain more than 20 km downstream. M e t h o d s . As a result of the flooding of agricultural lands, the waters of the Irpin River were polluted with products of human life (burial sites, cattle cemeteries, village toilets, places where livestock and birds are kept, fertilizers, decay products of plant remains) and flooded military equipment and ammunition. The purpose of this work is to study the zooplankton and ichthyofauna in the Irpin River and its tributaries the Moschunka and the Gorenka rivers. The study was conducted in the summer of 2023. A conical plankton net was used for zooplankton sampling. Quantitative parameters of zooplankton were determined according to Hensen's computational method in Bogorov's chamber using binoculars. R e s u l t s . Determination of the saprobiological state of the investigated water bodies was carried out according to the Pantle-Bucca method. Ichthyological samples were taken using a dip bag. During the experimental period, 10 species of zooplankton were found, which included rotifers, cladocera and copepods, and 3 species of fish. C o n c l u s I o n s . The obtained results indicate a significant decrease in the species richness of zooplankton in the studied reservoirs in comparison with last year's indicators, which can be explained by the consequences of anthropogenic load on the studied water ecosystems during the phase of active military operations within the Buchansky district.

ТАКСОНОМИЧЕСКИЙ СОСТАВ И КОЛИЧЕСТВЕННЫЕ ПОКАЗАТЕЛИ МАКРОЗООБЕНТОСА РЯДА ВОДОЕМОВ ЗАПАДНО-КАЗАХСТАНСКОЙ ОБЛАСТИ

The article presents the results of the study of macrozoobenthos communities of six lakes in the West Kazakhstan region in the summer-autumn period: Shalkar, Balykty Sarkyl, Edilsor, Glubinnoye, Prorva and Sulukol. Lakes Prorva and Sulukol are located within the steppe, the lakes Shalkar, Balykty Sarkyl, Glubinnoye - in the semi-desert, Lake Edilsor - in the desert zone. In total, 197 samples of zoobenthos were taken according to generally accepted hydrobiological methods. There are analized the indices of the number and biomass of aquatic organisms in the studied reservoirs. According to the results of the studies carried out, the organisms of 66 taxa from the groups Oligochaeta, Hirudinea, Bivalvia, Gastropoda, Crustacea, and Insecta were found in benthic samples. Of thesethere were found oligochaetes - 2 species, leeches - 1 species, bivalves and gastropods - 3 species each, crustaceans - 4 species and insects - 53 taxa. Among insects, dip-terans (23 taxa, of which chironomids - 18), mayflies, caddis flies, dragonflies, bugs and beetles were distinguished by the greatest species diversity. It was noted that in the composition of benthic communities, diptera larvae dominated in abundance, the main contribution to the biomass was made by bivalve molluscs. Calculations of the Shannon – Weaver index demonstrate a low species diversity of communities for all water bodies. The highest indices of species diversity were noted in Lake Edilsor - 1.64 bit / specimen, the lowest - in lakes Sulukol and Shalkar - 0.6 bit / specimen. and 0.7 bit / copy. respectively. According to the calculations of the saprobity index, lakes Glubinnoye, Prorva and Balykty Sarkyl belong to the ß-mesosaprobic zone, Lake Edilsor (S = 2.72) to the ɑ-mesosaprobic zone, and the indicators of Lake Sulukol (S = 3.8) correspond to the polysaprobic zone. The values of the saprobity indices of the studied lakes lie within the beta-mesosaprobic – polysaprobic zones. By water quality the studied lakes are assessed as moderately polluted and polluted. According to the classification of S.P. Kitaev (2007) the investigated water bodies are assessed as water bodies of medium feeding. The conducted studies have significantly expanded the taxonomic lists of benthic organisms in this region

PERMISSIBLE NUTRIENT LOADINGS ON INTERNATIONAL LAKES

Permissible phosphorus and nitrogen loadings were calculated for 17 international (transboundary) water bodies, which allow them to remain in an oligotrophic state. The calculations were performed by the methods suggested by Vollenweider, Vollenweider and Dillon, and Lozovik. The study was based on mathematical models linking the permissible nutrient loadings on water bodies with their morphometric, hydrological, and assimilation characteristics. A statistically significant relationship was established between the permissible nutrient loadings on sixteen transboundary lakes and one transboundary storage reservoir and their catchment areas. The revealed quantitative ratios enable environment agencies to make informed decisions about the need for reducing human pressure on the investigated water bodies.

СООБЩЕСТВА БЕСПОЗВОНОЧНЫХ ЗАРОСЛЕЙ МАКРОФИТОВ РАЗНОТИПНЫХ ВОДНЫХ ОБЪЕКТОВ ВОЛОГОДСКОЙ ОБЛАСТИ

In august 2018, fauna of aquatic macroinvertabrates from Persicaria amphibia (L.) Delarbre, Butomus umbellatus L. and Potamogeton perfoliatus L. was studied in Kubenskoe Lake as well as in Vozhe Lake and Mologa River in order to compare the phytophilic and bottom fauna of heterogeneous water bodies. Macrophyte-associated invertebrates and samples of zoobenthos in thickens (in total 37 samples were analyzed) were collected. 68 species of aquatic invertebrates were recorded, including 49 species from Kubenskoe Lake, 41 from Mologa River, and 31 from Vozhe Lake. In the thickets of three macrophyte species, less than a third of all macroinvertebrate richness from the investigated water bodies is recorded. The most abundant species were Endochironomus albipennis Meig., Glyptotendipes gripekoveni Kief., Cricotopus gr. sylvestris. By using cluster analysis, the fauna of all biotopes was divided into macrophyte-associated and bottom-associated. The abundance and biomass of invertebrates in zoophytos in most cases is 3–15 times higher than in zoobenthos. In lakes, species diversity in zoophytos is 1.5–5 times lower than in soil. In the Mologa River the species diversity of zoophytos, on the contrary, is slightly higher. In lakes in the trophic structure, filter-collectors predominate. In the Vozhe Lake a high proportion of predators in the biomass is also recorded. In the Mologa River the trophic structure is more various: along with the collector-filterers, scrapers, shredders and predators are represented. In comparison with research of the 1970s, community structure of macrophyte-associated invertebrates in Vozhe Lake has not practically changed. The dominance of E. albipennis was detected in the Kubenskoe Lake and that was not previously indicated for this reservoir. The species composition and abundance of aquatic macroinvertebrates is determined by the type of substrate (soil or plant), while the structure of communities depends primarily on a type of reservoir, and not on a type of thicket.

Understanding optical absorption associated with phytoplanktonic groups in the marginal seas

Marine phytoplankton absorption plays an important role in oceanic biological productivity and ecological environmental dynamics. Understanding the optical absorption variability associated with phytoplanktonic groups still remains a challenge. In this study, samples (n = 206) were collected for the marginal seas of the northwest Pacific Ocean from six cruise surveys that covered different seasons. Using in situ parameters, including phytoplankton absorption coefficients and concentrations of the phytoplanktonic groups derived from phytoplankton pigments collected with high-performance liquid chromatography (HPLC), we developed a Gaussian model to characterize the specific absorption spectra of eight phytoplanktonic groups, including diatoms, chlorophytes, cryptophytes, cyanobacteria, prymnesiophytes, prasinophytes, dinoflagellates, and chrysophytes, without the package effect. The model was established by accurately identifying for the numbers and locations of the Gaussian peaks and their corresponding half-wave widths. The proposed model produced promising results, and a leave-one-out cross validation generated R2 values exceeding 0.7 for the whole visible light range and above 0.85 (correspondingly MAPE <40%) for the simulated wave bands, excluding the range of 550–650 nm. Meanwhile, a comparison with several spectra observed in the lab showed a high degree of similarity, indicative of the superior performance of our model. Applying the documented specific absorption spectra to the investigated water bodies (whether water surface or profiles) enabled us to quantify the absorption coefficients from different phytoplanktonic groups and characterize their relative contributions to the total. The findings of this study support our understanding of the dynamics of phytoplankton community structure with optical data.

ПРИЧИНЫ НЕСОБЛЮДЕНИЯ ПРЕДЕЛЬНО ДОПУСТИМЫХ КОНЦЕНТРАЦИЙ ВЕЩЕСТВ 4Э КЛАССА ОПАСНОСТИ В КОНТРОЛЬНОМ СТВОРЕ МАЛЫХ РЕК – ПРИЕМНИКОВ ДРЕНАЖНО-СБРОСНЫХ ВОД

Purpose: to determine the reasons of non-compliance with the maximum permissible concentration of the hazard class 4e substances for water bodies of fishery significance (MPCfs) in the small rivers control point – receivers of drainage and waste waters (DWW). Materials and methods. The research object is the Salt river Semikarakorsk district Rostov region, the catchment area of which is an anthropogenically transformed agricultural landscape. As background concentrations, the data from official certificates on background concentrations in the investigated water body in the section 500 m above the DWW outlet are used. Results. The processes of salt-forming ions dilution belonging to the hazard class 4e substances in the aquatic environment of the Salt river when DWW enter it at the release site to the control point according to the method of A. V. Frolov – I. D. Rodziller were modified. It has been found that important characteristics of dilution processes are the ratio of the flow rates of the river and in the reservoir, as well as the background (Cf) and maximum permissible concentration of the substance. So, for the calcium ion Cf = 105 mg/dm³, MPCfs = 180 mg/dm³, the concentration of the substance in the most polluted jet from the release site to the control point varies from 180 to 107.8 mg/dm³. For sulfate ion Cf = 385 mg/dm³, MPCfs = 100 mg/dm³, the concentration varies from 100 to 232.5 mg/dm³. Conclusions. It has been found that the reasons for non-compliance with the maximum permissible concentrations of the hazard class 4e substances in the control point of small rivers are a high background concentration of salt-forming ions belonging to the 4e hazard class, comparable flows of rivers and DWW. The reasons for the weak dilution are the shallow depth of the river, low flow velocity, as well as high initial mineralization of natural water. Therefore, it is necessary to amend the Russian legislation in terms of regional permissible concentrations in water bodies, taking into account the regional characteristics of the hydrochemical regime of water bodies, river runoff, and the hydrochemical composition of the upper horizons of groundwater.

Progressive and Regressive Algae of the Genus &amp;lt;i&amp;gt;Navicula&amp;lt;/i&amp;gt; Bory (&amp;lt;i&amp;gt;Bacillariophyta&amp;lt;/i&amp;gt;) of Water Bodies of the Chirchik River Basin (Uzbekistan) and Protecshion

In the article, the authors present for the first time the progressive and regressing algae of the genus Navicula Bory (Bacillariophyta) the water bodies of the Chirchik River basin. The research was carried out during 2005-2012, 2018-2020 yy. with the National Universities of Uzbekistan and the Institutes and Botany of the Academy of Sciences of the Republic of Uzbekistan. 122 species and varieties of algae of the genus Navicula Bory have been identified. Among them, new species for water bodies, saprobic indicators were noted, the seasonality of algae was studied. The main new ideas the article are as follows: among the algae found, it is progressive algae 6. They are found very often, in or mass one field of view of the objective, their frequency of occurrence is equal to 5, 7, 9 points and is considered a resistant species various environmental conditions, being a promising algae with full life. 96 - less progressive algae, occurs rarely, the occurrence is equal to 5, 3 points and is less resistant and less promising algae with a sex life. 20 species and varieties are regressing algae, water bodies it meets only units (single), the frequency of occurrence is equal to 1 (one) point and is considered unstable algae of the investigated water bodies, the future, there is a threat to safety and Not Live! (No Life!) Needs protection. It was proposed to include the next issue of the Red Book of the Institute of Botany of the Academy of Sciences of the Republic of Uzbekistan, as well as to accept and include the list of protected microorganisms water bodies of Uzbekistan under the Committee for Ecology and Nature Protection of the Republic of Uzbekistan.

Фитопланктон в различных экотопах озера Отстойник (Самарская область)

This article presents the results of the study of the species composition and main indicators of the quantitative development of phytoplankton in various ecotopes (pelagic zone, phytal zone) of Lake Otstoynik. It is a small pond belonging to the system of Vasilievsky lakes of Togliatti, Samara Oblast. Initially it served as a receiver of nitrogen fertilizer production waste. In the 90s of XX century, the technological use of this lake was terminated but the rehabilitation works to restore the ecosystem of the reservoir was not carried out. Modern condition of the ecosystem is entirely the result of self-purification and self-healing. Therefore, the materials presented in this article may be of interest to experts on environment, especially those who work in the field of cost-benefit analysis in predicting the development of a "zero" scenario, i.e. without interference through recreational activities in the recovery processes of disturbed aquatic ecosystems. The study deals with the species composition of the plankton algoflora in various ecotopes of the reservoir (open pelagic zone and phytal zone formed by reed), its floral and еcological/geographical analysis. In addition, it considers seasonal succession of phytoplankton in different ecotopes in the period from 2014 to 2016, analyzes quantitative indicators of development (abundance, biomass) of phytoplankton, the role of the major divisions of algae in their formation. We estimated the level of species diversity in different ecotopes of the reservoir with the use of the Shannon-Weaver index. In terms of quantitative development of phytoplankton, the level of water trophies was estimated. Based on the data of sapro/biological analysis, the pollution level has been established and the class of water quality in the investigated water body has been determined.

Odonata and Anthropogenic Salinization of Inland Waters

The anthropogenic salinization of inland waters and its effect on freshwater biota are current environmental problems. This salinization leads to changes in the natural environment that are ecologically undesirable and not indifferent to humans. The widespread use of agents for road deicing has become one of the three most important factors of anthropogenic salinization of fresh water (along with agricultural activities and mining) in countries with temperate and cold climate. Today, the main components of these agents are Na and Ca chlorides—cheap and easily available natural materials. Their mixture with sand, used in deicing practice, is usually stored in bulk in special open-air areas all year round. The impact of atmospheric precipitation makes this mixture a source of salinization of the surrounding soils and waters. In 2015, 2016, and 2018, the salinity of inland waters was recorded near the long-term open storage of antiicing agents in Kaluga oblast. The anthropogenic nature of salinization of the investigated water bodies is established. The main components of salinization of water bodies in the study area are Na and Ca chlorides. The maximum degree of salinization in the studied conditions is 4‰ (ppm); the degree of salinity depends on the distance of the water body from the road-salt storage. The influence of anthropogenic salinity on dragonflies, mainly of the species Coenagrion puella L., is studied. It is found that the negative effect of high water salinity is expressed only in the slowdown of the development of individuals with a high level of fluctuating asymmetry, the number of which in the population is not determined by water salinity. High water salinity leads to changes only in the timing of emergence of imagoes with high FA. It is assumed that dragonflies as a mass object of freshwater biota are obviously not significantly exposed to anthropogenic salinization.

The fish population of small water bodies in Lake Onego catchment, and their prospective uses

The results of the surveys of two small lakes located in the western and southern parts of the Republic of Karelia (Sukkozero and Kedrozero) are reported. Hydrological and hydrochemical indices were analyzed. The water bodies are of glacial genesis, and belong to the catchment of Lake Onego. Human population in the catchments of the lakes is scarce, there are no large industrial enterprises, fish farms, etc. The lakes are classified as β-oligotrophic on the trophicity scale. Some bays and sites of Lake Kedrozero have acquired mesotrophic traits. Hydrobiological data, including the fish population of the lakes, are presented in detail for the first time. The fish species composition, length-weight growth and diet of the prevalent species were studied. The fish population of Lake Sukkozero is represented by 10 species, of Lake Kedrozero – by 14 species. Smelt, perch, roach and bream are the most abundant in both lakes. Atlantic salmon, brown trout, whitefish and vendace are valuable fish. Salmon and trout are included in the Red Data Book of Karelia. A higher growth rate is observed in fish from Kedrozero, obviously due to the richer food resources. A comparative analysis of the data shows that the investigated water bodies have remained practically unchanged over a long time. This situation is now very rare, not only in the region, but also in Russia at large. Water bodies can serve as benchmarks for assessing the state of aquatic ecosystems under a significantly increased human impact. Small lakes, due to the lack of industrial-scope fishing, are promising for amateur, sport fishing and tourism development.

Does the location of coastal brackish waters determine diversity and abundance of zooplankton assemblages?

Habitat conditions may shape the abundance and community structure of planktonic fauna. In this study, we investigated whether reservoirs with different locations and drainage basins also differed in the structure and abundance of zooplankton. The studies were conducted in 2010-2011 between June and October in the Vistula Lagoon and Lake Lebsko. The zooplankton was dominated mainly by small eurytopic organisms belonging to Rotifera. Plankton crustaceans showed a limited diversity of species. Copepods were predominant, while Cladocera were observed sporadically in more freshwater habitats. In the first experimental season (2010), the Vistula Lagoon and Lake Lebsko showed a comparable taxonomic structure and an abundance of investigated zooplankton; a substantially higher density was recorded in Lake Lebsko in 2011, although the taxonomic diversity was higher in the Vistula Lagoon. Zooplankton biomass in a given season differed between these 2 water bodies, but not statistically significantly. The differences in location in the investigated water bodies impacted zooplankton assemblage structure and abundance. The drainage basin type (urbanized areas, forested areas, waterlogged areas) appeared to influence zooplankton species richness significantly.

Water quality in forests small retention reservoirs in southern Poland – case study

Abstract This paper provides an analysis of water quality in three newly constructed small water retention reservoirs (Rudziczka, Niemysłowice I and Paciorkowy) located in forested areas of the forest district Prudnik in the Opolskie Province (southern Poland). The main purpose of these reservoirs is not only water retention, but also flood safety, fire protection, recreation and ecology. This paper presents the results of research carried out in December 2014 and May 2015. The assessment of water quality was performed in accordance with the applicable provisions on water quality assessment. Moreover, an assessment of eutrophication of water and of the usability of water in reservoirs is given (an analysis of suitability of water as a fish habitat). The research shows that the investigated waters are of quality class I in terms of the values of electrolytic conductivity, nitrates, nitrites, dissolved oxygen CODMn, calcium, magnesium and general hardness. In terms of the temperature (the Rudziczka reservoir), and the content of ammonia and phosphates they were of quality class II. The reaction, BOD5 and sulphates and chlorides content exceeded the threshold values for class II. It was also found that the investigated waters are not eutrophic. Based on the indicators such as reaction, dissolved oxygen, ammonia nitrogen and temperature, the waters in all the reservoirs except for Rudziczka met the quality requirements for habitats of salmonids and cyprinids. The living conditions for fish are deteriorated most by the increased levels of BOD5 and of nitrites in the Rudziczka and Paciorkowy reservoirs. The analysis of seasonal fluctuation in concentrations of water quality indicators in the investigated water bodies showed that in winter the concentrations of indicators were higher for nitrates, phosphates, electrolytic conductivity, calcium and general hardness and lower for temperature, reaction, nitrites, ammonia and dissolved oxygen. While the water in the Paciorkowy reservoir had the worst quality, the surface water in the Rudziczka reservoir had the best quality. The research initiated in small forests water retention reservoirs provides preliminary information on water quality and the importance of investigated reservoirs for increased retention.

Zooplankton in water bodies of coastal marshes in Malozemelskaya tundra

The composition and structure of zooplankton in small water bodies (ponds and puddles) of Pechora Bay coastal marshes have been studied. The investigated water bodies are confined to three ecotopes (low, medium, and high marshes), distinguished on the coastal strip according to the degree of soil salinity and vegetation quality along the ecological profile perpendicular to the coast. It has been revealed that the species composition and zooplankton abundance are dependent on the type of ecotope and water salinity. The trophic structure of the community shows the difference in food resources between the studied ecotopes.

Dolichospermum and Aphanizomenon as neurotoxins producers in some Russian freshwaters

Last decades, cyanobacterial blooms have been commonly reported in Russia. Among the boom-forming species, potential toxin producers have been identified. The aim of this paper was to study the presence of neurotoxic compounds - saxitoxins and anatoxin-a - in water bodies from different regions of Russia. We also made attempts to identify the neurotoxin-producing genera. The good convergence of the results obtained by light microscopy, PCR and LC-MS/MS analyses indicated the presence of active neurotoxin producing species in all investigated water bodies. Saxitoxin was detected in phytoplankton from 4 water bodies in Central European Russia and West Siberia, including lake and reservoirs used as a source for potable water. The water bodies differed with the respect of saxitoxin producers which belonged to Aphanizomenon and/or Dolichospermum genera. For the first time, we obtained quantitative data on the intracellular saxitoxin concentration in Russian freshwaters using LC-MS/MS. Anatoxin-a was detected only in lakes of Northwestern Russia. In the eutrophic shallow Lower Suzdal Lake, Aphanizomenon was the stated anatoxin-a-producing genus. In the large shallow artificial hypertrophic Sestroretskij Razliv Lake, it was very likely that both dominant species - Aphanizomenon flos-aquae and Dolichospermum planctonicum - were anatoxin-a producers.

New data on alien species of parasites and hosts in the ecosystem of Lake Glubokoe (Moscow oblast, Russia)

Lake Glubokoe (Moscow oblast, Russia) is one of the most investigated water bodies of Europe. We detected new parasite species for the ecosystem of the lake (alien for territory of Europe): coccidian Goussia obstinata (in invasive alien fish Perccottus glenii) and copepod Neoergasilus japonicus (on aboriginal ruff Gymnocephalus cernuus). The given coccidian is host-specific for P. glenii and was introduced in the lake together with its host. Participation of P. glenii in circulation of recorded heteroxenous helminthes (Isthmiophora melis, Azygia lucii, and Raphidascaris acus) was revealed. This is confirmed by the data on trophic links of their obligatory definitive hosts (American mink Neovison vison and northern pike Esox lucius) with P. glenii in Lake Glubokoe.