Protection Of Aquatic Ecosystems Research Articles

Effects of aquatic heavy metal intoxication on the level of hematocrit and hemoglobin in fishes: A review

Environmental pollution caused due to the presence of heavy metals has become a great concern as it has an adverse effect on almost all types of ecosystem. In this sense, these pollutants have a tendency to pollute the aquatic ecosystem, thus badly affecting the health of aquatic organisms. As a result, toxicological studies believe them to be the most harmful pollutants in the aquatic environment. Among all the aquatic organisms, fish—being a chief organism in this system—become the easiest victim of these pollutants. Heavy metals enter fish bodies through the alimentary system by consumption of polluted food, or through the gills, and skin. They are finally delivered by the bloodstream to the organs and tissues where they accumulate after absorption. Ultimately, in this way heavy metals make their way into humans through the food chain. The fluctuations in the hematological values may serve as an initial indicator of the toxicant’s impact on fish health. It has been observed that when pollutants impact the quality of the aquatic medium, the first consequence is apparent in the form of physiological changes in fish, which are reflected in one or more hematological parameters, such as hemoglobin, hematocrit, red blood cell count, white blood cell count, etc. As a result of these alterations, fish become weak, anemic, and more susceptible to diseases. Over the past several decades, a vast number of studies have been reported on the qualitative and quantitative variations in hematological parameters due to the presence of heavy metal intoxication. Heavy metal contamination of water resources not only degrades the water quality but also negatively impacts the quality of food in the form of fish proteins. Therefore, this article sheds light on the effects of heavy metals on hemoglobin and hematocrit of fish hematology and calls for more attention to the protection and preservation of aquatic ecosystems, particularly those contaminated with heavy metals.

Effects of return flows on stream water quality and availability in the Upper Colorado, Delaware, and Illinois River Basins

Understanding effects of human water use and subsequent return flows on the availability and suitability of water for downstream uses is critical to efficient and effective watershed management. We compared spatially detailed estimates of stream chemistry within three watersheds in diverse settings to available standards to isolate effects of wastewater and irrigation return flows on the suitability of downstream waters for maintaining healthy aquatic ecosystems and for selected human uses. Mean-annual flow-weighted total and source-specific concentrations of nitrogen and phosphorus in individual stream reaches within the Upper Colorado, Delaware, and Illinois River Basins and of total dissolved solids within stream reaches of the Upper Colorado River Basin were estimated from previously calibrated regional watershed models. Estimated concentrations of both nitrogen and phosphorus in most stream reaches in all three watersheds (at least 78%, by length) exceed recommended standards for the protection of aquatic ecosystems, although concentrations in relatively few streams exceed such standards due to contributions from wastewater return flows, alone. Consequently, efforts to reduce wastewater nutrient effluent may provide important local downstream benefits but would likely have minimal impact on regional ecological conditions. Similarly, estimated mean-annual flow-weighted total dissolved solids concentrations in the Upper Colorado River Basin exceed standards for agricultural water use and (or) the secondary maximum contaminant level (SMCL) for drinking water in 52% of streams (by length), but rarely due to effects of irrigation return flows, alone. Dissolved solids in most tributaries of the Upper Colorado River are attributable primarily to natural sources.

Public-Private Partnership in the Context of Sustainable Development on the Example of the Water and Wastewater Sector

The purpose of this paper is to analyze the implementation of investments in the water and sewage sector in Poland and other European countries using the Public-Private Partnership (PPP) formula. The paper identifies the strengths and weaknesses, opportunities and threats arising from the use of this formula for local government public tasks for the delivery and treatment of domestic wastewater, in the context of EU legislation. It also examines the validity of the use of PPP in the context of the implementation of the principle of sustainable development in water management. PPPs are commonly used to deliver strategic public services under financial limitations. Countries such as the United Kingdom and Ireland, based on years of experience and good practices, are effectively implementing PPP projects, including those in the water and sewerage sector. The provision of treated drinking water and the treatment of municipal wastewater is a fundamental task ensuring an adequate quality of life for people by maintaining public health at an appropriate level. The fact that water and sanitation infrastructure and service provision in this sector is expensive, both at the construction and operational stages, has led countries at different levels of development to turn to public-private partnerships. Properly managed PPP projects secure the interests of both the private and public partner and the end user of the services. The analysis of data and examples of European PPPs in the water and wastewater sector shows that PPPs have been successful for most public entities that have chosen them. Good practices from Scotland, Ireland and Poland, as well as projects that have experienced difficulties, show that stable and friendly legislation, thorough pre-feasibility studies and an appropriate allocation of risk make PPPs successful. In the context of the conducted analysis, PPP is a tool enabling the realization of tasks in the water and sewage sector, where the public party’s budget possibilities are limited. Moreover, PPP is a component of the realization of the sustainable development principle. The idea that the use of natural resources, including water, which is fundamental to the biological and cultural needs of humankind, should be met in such a way as to save them for future generations, is realized in PPP projects. This paper demonstrates that the use of financial assembly opportunities in PPPs makes it possible to significantly intensify the construction of new and upgrading of existing water and wastewater infrastructure. It contributes to the protection of aquatic ecosystems and securing public health associated with living in direct proximity to surface water and discharging wastewater without affecting the natural environment and human habitats.

ASSESSMENT OF SURFACE WATER QUALITY (ON THE EXAMPLE OF THE CHUMYSH RIVER)

The surface water pollution issue is urgent as it is the most extensive issue. Large-scale pollution of the environment causes damage to rivers, lakes, water reservoirs, and soils. Pollutants and products of their transformations sooner or later come from the atmosphere to the surface of the Earth. Issues of clean water and protection of aquatic ecosystems become increasingly acute as the historical development of society develops. Furthermore, the influence of scientific and technological progress on nature rapidly increases. Currently, there is a unified criterion for assessing water quality is the maximum permissible concentration (MPC) of substances contained in it in the Russian Federation. The Chumysh River flows in the Kemerovo Region and Altai Krai and is a tributary of the Ob River. The Chumysh River has a length of 644 km and a basin area of 23,900 square km. The assessment of the surface water quality of the Chumysh River is carried out based on data processing of the Roshydromet Federal Service for Hydrometeorology and Environmental Monitoring of Russia, which is located on the studied water object near the city of Zarinsk. The primary research goal is to assess the quality of surface waters of the Chumysh River in Zarinsk and Talmenka urban-type settlement. During the study period (nine years), the authors have identified the elements as the primary substances that have provided the most critical contribution to pollution. A comprehensive assessment has been carried out for these substances, and the substances that provide the most significant contribution to surface water pollution are selected based on the product of the points. This factor is of great importance for developing the measures that aim at their purification and planning the future use of the Chumysh River waters.

Temporal variation of imidacloprid concentration and risk in waterways discharging to the Great Barrier Reef and potential causes

The widely used neonicotinoid insecticide imidacloprid has emerged as a significant risk to surface waters and the diverse aquatic and terrestrial fauna these ecosystems support. While herbicides have been the focus of research on pesticides in Australia's Great Barrier Reef catchment area, imidacloprid has been monitored in catchments across the region since 2009. This study assessed the spatial and temporal dynamics of imidacloprid in 14 waterways in Queensland, Australia over seven years in relation to land use and concentration trends. Imidacloprid could be quantified (i.e., concentrations were greater than the limit of reporting) in approximately 54% of all samples, but within individual waterways imidacloprid was quantified in 0 to 99.7% of samples. The percent of each catchment used to grow bananas, sugar cane and urban explained approximately 45% of the variation in imidacloprid concentrations and waterway discharge accounted for another 18%. In six waterways there were significant increases in imidacloprid concentrations and the frequency and magnitude of exceedances of aquatic ecosystem protection guidelines over time. Overall, the risk posed by imidacloprid was low with 74% of samples protecting at least 99% of species but it was estimated that upto 42% of aquatic species would experience harmful chronic effects. Potential explanations of the changes in imidacloprid were examined. Not surprisingly, the only plausible explanation of the increases was increased use of imidacloprid. While field-based measurement of the effects of imidacloprid are limited in the Great Barrier Reef Catchment Area (GBRCA) the risk assessment indicates that biological harm to aquatic organisms is highly likely. Action to reduce imidacloprid concentrations in the GBRCA waterways is urgently required to reverse the current trends and mitigate environmental impacts.

Unveiling biogeographical patterns of the ichthyofauna in the Tuichi basin, a biodiversity hotspot in the Bolivian Amazon, using environmental DNA.

To date, more than 2400 valid fish species have been recorded in the Amazon basin. However, some regions remain poorly documented. This is the case in the Beni basin and in particular in one of its main sub-basins, the Tuichi, an Andean foothills rivers flowing through the Madidi National Park in the Bolivian Amazonia. The knowledge of its ichthyological diversity is, however, essential for the management and protection of aquatic ecosystems, which are threatened by the development of infrastructures (dams, factories and cities), mining and deforestation. Environmental DNA (eDNA) has been relatively little used so far in the Amazon basin. We sampled eDNA from water in 34 sites in lakes and rivers in the Beni basin including 22 sites in the Tuichi sub-basin, during the dry season. To assess the biogeographical patterns of the amazonian ichthyofauna, we implemented a metabarcoding approach using two pairs of specific primers designed and developed in our laboratory to amplify two partially overlapping CO1 fragments, one of 185bp and another of 285bp. We detected 252 fish taxa (207 at species level) among which 57 are newly identified for the Beni watershed. Species compositions are significantly different between lakes and rivers but also between rivers according to their hydrographic rank and altitude. Furthermore, the diversity patterns are related to the different hydro-ecoregions through which the Tuichi flows. The eDNA approach makes it possible to identify and complete the inventory of the ichthyofauna in this still poorly documented Amazon basin. However, taxonomic identification remains constrained by the lack of reference barcodes in public databases and does not allow the assignment of all OTUs. Our results can be taken into account in conservation and management strategies and could serve as a baseline for future studies, including on other Andean tributaries.

Water Management Balance as a Tool for Analysis of a River Basin with Conflicting Environmental and Navigational Water Demands: An Example of the Warta Mouth National Park, Poland

Allocating finite water resources between different water uses is always a challenging task. Searching for a solution which satisfies the water needs (requirements) of all water users without compromising the water requirements of river ecosystems calls for analyzing different water management options and their expected consequences. Water management balances are usually used for comparison of water resources with the needs of water users. When aquatic and water dependent ecosystems are considered in a similar manner as other users, searching for the optimum water resources allocation, without neglecting requirements of the natural environment, is possible. This paper describes basic modeling assumptions and methodological solutions, which allow for taking into account some tasks related to the protection of aquatic and water dependent ecosystems. The water balance model, developed for a catchment comprising the Warta Mouth National Park, was applied to find out whether supplying adequate amounts of water for conservation (or restoration) of wet meadows and wetland habitats in the area is possible, while still satisfying the demands of other water users.

Fundamentals of commodity fishery for the cultivation of silver carp in polyculture with carp in the conditions of the LLC “Kovcheg” of the Kyiv

This scientific article describes the technology and stages of designing a fishery for growing silver carp in polyculture with carp in conditions of the LLC “Kovcheg” of the Kyiv. In the conditions of this economy the project of cultivation of fish in polyculture was developed, where calculations of average monthly temperature of ponds, content of dissolved oxygen in water were carried out, indicators of a source of water supply of ponds were analyzed, economic efficiency of cultivation of silver carp in polyculture with carp was carried out. Fish farms have a number of significant problems today, that prevent full and easy development – these are financial difficulties in the state, namely: disruption of economic ties, deterioration of the ecological condition of inland waters, insufficient work on the reproduction of fish stocks. In order to get fish farming out of the crisis, ensure sustainable development of the industry, strengthen the country's food independence, it is necessary first of all to solve issues related to environmental and economic problems of fisheries development, improving the economic mechanism of fisheries management, intensification of investment processes and innovations aquatic living resources. The fisheries sector includes the extraction, processing, reproduction and increase of stocks of fish and other aquatic organisms in natural and artificial reservoirs. It provides valuable food, feed, medicine and technical products. Fisheries are aimed at preserving and improving fish stocks in natural reservoirs and breeding fish in artificial reservoirs. In order to ensure food security of Ukraine, it is necessary to work on the following areas: scientific substantiation of the raw material base and rational fishing, protection of aquatic ecosystems, technology of processing of aquatic fish resources.

No evidence of widespread algal bloom intensification in hundreds of lakes

Algal blooms, the rapid proliferation of algal biomass often to nuisance or harmful levels, diminish aquatic ecosystem services. Freshwater blooms can cause substantial economic damage by interrupting water supply, limiting recreation, and reducing property values. The interaction between eutrophication and climate change has been hypothesized to drive widespread intensification of blooms in inland waters, although there is little empirical evidence that this trend is pervasive. Here, we show that bloom intensification in inland waterbodies – defined as trends in chlorophyll‐a of increasing bloom magnitude, severity, or duration – has not been widespread for hundreds of lakes in the US. Only 10.8% of the 323 waterbodies analyzed had significant bloom intensification. Conversely, 16.4% of the waterbodies had significant decreasing trends during the same period. While it is encouraging that bloom intensification is not currently widespread, continued efforts toward aquatic ecosystem protection and restoration are imperative for maintaining ecosystem services into the future.

High‐frequency multi‐solute calibration using an in situUV–visible sensor

AbstractMonitoring the temporal variation of solute concentrations in streams at high temporal frequency can play an important role in understanding the hydrological and biogeochemical behaviour of catchments. UV–visible spectrometry is a relatively inexpensive and easily used tool to infer those concentrations in streams at high temporal resolution. However, it is not yet clear which solutes can be modelled with such an in‐situ sensor. Here, we installed a UV–visible spectrometer probe (200–750 nm) in a high‐altitude tropical Páramo stream to record the wavelength absorbance at a 5‐min temporal resolution. For calibration, we simultaneously sampled stream water at a 4‐h frequency from February 2018 to March 2019 for subsequent laboratory analysis. Absorbance spectra and laboratory‐determined solute concentrations were used to identify the best calibration method and to determine which solute concentrations can be effectively inferred using in situ spectrometry through the evaluation of six calibration methods of different mathematical complexity. Based on the Nash–Sutcliffe efficiency (NSE) and Akaike information criterion metrics, our results suggest that multivariate methods always outperformed simpler strategies to infer solute concentrations. Eleven out of 21 studied solutes (Al, DOC, Ca, Cu, K, Mg, N, Na, Rb, Si and Sr) were successfully calibrated (NSE >0.50) and could be inferred using UV–visible spectrometry even with a reduced daily sampling frequency. It is worth noting that most calibrated solutes were correlated with wavelengths (WLs) in the low range of the spectra (i.e., UV range) and showed relatively good correlation with DOC. The latter suggests that estimation of metal concentrations could be possible in other streams with a high organic load (e.g., peat dominated catchments). In situ operation of spectrometers to monitor water quality parameters at high temporal frequency (sub‐hourly) can enhance the protection of human water supplies and aquatic ecosystems as well as providing information for assessing catchment hydrological functioning.

Efficient phosphate removal by dendrite-like halloysite-zinc oxide nanocomposites prepared via noncovalent hybridization

The efficient capture of phosphate from contaminated water is crucial for aquatic ecosystem protection and drinking water utilities, but designing nanohybrid materials with high phosphate-adsorption capacity remains challenging. This study reports on a way to tackle this challenge, by creating a dendrite-like nanocomposite through the functionalization of tubular halloysite (Hal) clay mineral with ZnO nanoparticles. Specifically, ZnO nanoparticles were coated on the surfaces of Hal, thereby by providing adsorption sites capable of removing phosphate. Furthermore, dendrite-like ZnO-Hal can grasp phosphate firmly because of the strong binding of ZnO nanoparticles to phosphate. Thus, the ZnO coating with its high adsorption affinity provides a new benchmark for the scavenging of phosphate in water. The adsorption capacity of ZnO-Hal exhibits an exceptionally high phosphate capacity of 97.3 mg P·g−1 under the equilibrium phosphate concentration of 346 mg P·L−1, which is superior to most other reported phosphate adsorbents. After normalizing to the content of ZnO in the nanocomposite, the phosphate adsorption capacity of ZnO-Hal is higher than that of the pure ZnO particles. The equilibrium adsorption isotherm and kinetic data of ZnO-Hal were fitted well with Freundlich and pseudo-second-order models, respectively. Moreover, good adsorption performance of ZnO-Hal was confirmed in the presence of competitive anions at molar ratios of 1:10 or 1:100 (phosphate-to-anion ratio), both in the acidic and neutral pH ranges, and in domestic wastewater as well. The adsorption mechanism was investigated; those results revealed that phosphate was removed by the formation of a zinc phosphate mineral hopeite on the Hal surfaces. This work, therefore, provides a novel material for removing phosphate from water for environmental remediation purposes.

China is establishing its water quality standards for enhancing protection of aquatic life in freshwater ecosystems

Water quality standards (WQS) are derived to give scientifically-robust and legally-binding guidance on acceptable risks of chemical contaminants with a view to protecting aquatic ecosystems and biodiversity. In China, anthropogenic chemical pollution of water bodies is a major threat to aquatic life. China, therefore, urgently needs to establish a scientifically-robust, functional WQS system that will ensure chemical contaminants are maintained at acceptable levels that protect aquatic ecosystems. In this article, we review the significant need for comprehensive national-scale protection of aquatic ecosystems and the challenges associated with using the Environmental Quality Standards for Surface Water (GB3838−2002) to protect aquatic ecosystems in China. We have also summarized information about recent developments in the aquatic life criteria for freshwater ecosystems in China and in other jurisdictions. Finally, we have made recommendations for the future direction and development of WQS in China that could be tailored to suit regional environmental characteristics and native aquatic species so as to offer better, regional-specific protection to aquatic life in freshwater ecosystems.

Oxidative stress and antioxidant defense in response to Dimethyl Phthalate in Chlorella vulgaris

Dimethyl phthalate (DMP) is a common organic pollutant that can accumulate in aquatic organisms and pose a threat to aquatic ecosystems. Many studies have shown that DMP is toxic to marine organisms, but the toxicity mechanism of DMP in microalgae is still unclear. We measured indicators of cell growth, oxidative damage and antioxidant enzyme activity in Chlorella vulgaris exposed to DMP. The degree of growth inhibition of C. vulgaris cells increased with the increase of DMP concentration. Hydrogen peroxide and malondialdehyde contents increased significantly in C.vulgaris exposed to 800 mg/L DMP. Glutathione peroxidase and Superoxide dismutase activities both decreased in C. vulgaris exposed to 100 mg/L DMP. These data indicated that DMP treatment altered the redox status of C. vulgaris and that oxidative damage may be the main mechanism of DMP toxicity. The results lay a foundation for understanding the impact of DMP on C. vulgaris stress and provide a theoretical basis for the protection of aquatic ecosystems.

Spatial Distribution Characteristics and Sources of Nutrients and Heavy Metals in the Xiujiang River of Poyang Lake Basin in the Dry Season

In December of 2019, a total of 114 river water samples were collected from 38 sampling sites in the Xiujiang River of the Poyang Lake Basin for three consecutive days. The temperature (T), pH, dissolved oxygen (DO), chemical oxygen demand (CODCr), five-day biochemical oxygen demand (BOD5), total nitrogen (TN), ammonia nitrogen (NH4+-N), total phosphorus (TP), and concentrations of heavy metals (Cr, Cu, Zn and As) of the samples were measured. The results showed that the average concentrations of heavy metals in the mainstream of the Xiujiang River were Cu > Zn > Cr > As, and those in the main tributary of Xiujiang River (named as the Liaohe tributary) were Zn > Cu > Cr > As, which met the class III of the Environmental Quality Standards for Surface Water in China. However, it was founded that TN and NH4+-N in some agricultural areas had not met the class III standard of surface water. Hierarchical clustering analysis grouped sampling sites into four clusters. Clusters 1, cluster 2, cluster 3, and cluster 4 corresponded to an urban industrial area, rural mountainous area, primitive mountainous area, and agricultural area, respectively. The majority of the sampling sites were classified as mountainous rural areas less impacted by human activities, while the Liaohe tributary were urban industrial areas impacted more by human activities. Principal component analysis and correlation analysis results showed that variation of heavy metals and nutrient elements in Xiujiang River is related to the heterogeneity of human activities, which is mainly affected by urban industrial and agricultural pollution, and natural environments of the river with different background values. The results obtained in the current study will potentially provide a scientific basis for the protection and management of freshwater resources and aquatic ecosystems in the Xiujiang River and Poyang Lake Basin.

Improving remote sensing retrieval of water clarity in complex coastal and inland waters with modified absorption estimation and optical water classification using Sentinel-2 MSI

The estimation of water clarity in coastal and inland waters from satellite images is limited by significant uncertainties attributable to the optical complexity of these waters. To address this issue, we propose an improved semi-analytical model for retrieving the Secchi disk depth (ZSD) based on the mechanistic model (Lee model) developed by Lee et al. (2015). In the Lee model, a quasi-analytical algorithm (QAA) was employed to estimate the total absorption coefficient (a(λ)) and total backscattering coefficient (bb(λ)) to retrieve the diffuse attenuation coefficient (Kd(λ)). ZSD was then estimated by remote sensing reflectance (Rrs) and Kd. In this study, two improvements were made to the Lee model based on the band specifications of the Sentinel-2 Multispectral Instrument (MSI). First, the reference wavelength (λ0) was shifted from 560 nm and 665 nm to the longer red edge band 705 nm, and the modified empirical formula for estimating a(λ0) was applied to improve ZSD retrieval. Second, waters were classified into different optical water types (OWTs), and the optimal ZSD algorithm was identified for each OWT to further improve the accuracy of ZSD estimation. The proposed model (denoted as QAA_OWT) was calibrated and evaluated with in situ data (N = 399) collected from waters with various optical properties including a lake (Daihai Lake) dominated by colored dissolved organic matter (CDOM), a macrophytic lake (Ulansuhai Lake), and coastal water (the Bohai Sea) dominated by suspended sediments. The validation showed that QAA_OWT improved the accuracy of ZSD retrieval (0.18–5.0 m), with the averaged percentage difference (MAPD) decreasing from 31.9% to 24.9% and the root mean square deviation (RMSD) decreasing from 0.38 m to 0.32 m. The model was further applied to satellite images from the Sentinel-2 Multispectral Instrument (MSI) and independently assessed based on in situ-satellite match-ups (N = 31). The results verified the reliability of the model (MAPD = 31.8%, RMSD = 0.16 m). Time series MSI-derived ZSD maps clearly characterized the spatio-temporal patterns of the water clarity of Daihai Lake. Such maps are of significance in the accurate evaluation of the effectiveness of pollution control measures and aquatic ecosystem protection for lakes with low water quality. Sensitivity analysis revealed the robustness and insensitivity of the proposed model to input noise. This model could be applicable to many satellite sensors with spectral bands similar to those of Sentinel-2 MSI. Furthermore, it can be used as an effective tool for highly accurate remote sensing retrieval of ZSD in optically complex coastal and inland waters.

When treatment increases the contaminant's ecotoxicity: A study of the Fenton process in the degradation of methylene blue

The degradation of dyes can generate harmful by-products, thereby requiring the need to evaluate the toxicity to aquatic organisms. This study aims to evaluate the chronic ecotoxicity of methylene blue dye degraded by the Fenton process using the non-target planarian Girardia tigrina as a sensitive bioindicator of environmental contamination. The bioassays evaluated the lethality of several concentrations of the untreated and degraded dye methylene blue (MB), as well as, their sub-lethal effects on locomotion, feeding, regeneration, and reproduction. In both acute and chronic tests, the degraded dye had a stronger toxic effect when compared to the untreated dye. This negative effect after treatment was mainly associated with the presence of residual hydrogen peroxide and iron (and consequently the hydroxyl radical formed). We conclude that the utilization of the Fenton process using less oxidizing agents should be considered as important alternatives for the protection of aquatic ecosystems, without compromising the efficient removal of MB.

Wastewater effluents cause microbial community shifts and change trophic status

Widespread wastewater pollution is one of the greatest challenges threatening the sustainable management of rivers globally. Understanding microbial responses to gradients in environmental stressors, such as wastewater pollution, is crucial to identify thresholds of community change and to develop management strategies that protect ecosystem integrity. This study used multiple lines of empirical evidence, including a novel combination of microbial ecotoxicology methods in the laboratory and field to link pressure-stressor-response relationships. Specifically, community-based whole effluent toxicity (WET) testing and environmental genomics were integrated to determine real-world community interactions, shifts and functional change in response to wastewater pollution. Here we show that wastewater effluents above moderate (>10%) concentrations caused consistent significant shifts in bacterial community structure and function. These thresholds of community shifts were also linked to changes in the trophic state of receiving waters in terms of nutrient concentrations. Differences in the community responses along the effluent concentration gradient were primarily driven by two globally relevant bacterial indicator taxa, namely Malikia spp. (Burkholderiales) and hgcI_clade (Frankiales). Species replacement occurred above moderate effluent concentrations with abundances of Malikia spp. increasing, while abundances of hgcI_clade decreased. The responses of Malikia spp. and hgcI_clade matched gene patterns associated with globally important nitrogen cycling pathways, such as denitrification and nitrogen fixation, which linked the core individual taxa to putative function and ecosystem processes, rarely achieved in previous studies. This study has identified potential indicators of change in trophic status and the functional consequences of wastewater pollution. These findings have immediate implications for both the management of environmental stressors and protection of aquatic ecosystems.

Acartia tonsa Dana 1849 as a Model Organism: Considerations on Acclimation in Ecotoxicological Assays.

The copepod Acartia tonsa was standardized as model organism in acute toxicity bioassays due to its key position in coastal food chains and high sensitivity. Once bioassays are performed according to a protocol their results may become tools for the protection of aquatic ecosystems. However, there are divergences in bioassays methods using A. tonsa. This study aimed to investigate: (i) the need for acclimation of A. tonsa collected from the environment for use in acute toxicological bioassays; and (ii) differences in sensitivity between copepods collected from the environment and laboratory-grown copepods. Laboratory-grown copepods are more sensitive to SDS thanA. tonsa from theenvironment. The acclimation time of 30h helped organisms to recover from stress of collection/handling and changing environment/conditions. Therefore, laboratory-grown copepods showed to be more sensitive than organisms from environment; and for ecotoxicological bioassays acclimating A. tonsa collected from the environment for 30h can be adopted.

The Fellowship of the Ring Test: DNAqua-Net WG2 initiative to compare diatom metabarcoding protocols used in routine freshwater biomonitoring for standardisation

During the past decade genetic approaches have been developed to monitor biodiversity in aquatic ecosystems. These enable access to taxonomic and genetic information from biological communities using DNA from environmental samples (e.g. water, biofilm, soil) and methods based on high-throughput sequencing technologies, such as DNA metabarcoding. Within the context of the Water Framework Directive (WFD), such approaches could be applied to assess Biological Quality Elements (BQE). These are used as indicators of the ecological status of aquatic ecosystems as part of national monitoring programs of the european network of 110,000 surface water monitoring sites with 79.5% rivers and 11% lake sites (Charles et al. 2020). A high-throughput method has the potential to increase our spatio-temporal monitoring capacity and to accelerate the transfer of information to water managers with the aim to increase protection of aquatic ecosystems. Good progress has been made with developing DNA metabarcoding approaches for benthic diatom assemblages. Technological innovation and protocol optimization have allowed robust taxonomic (species) and genetic (OTU, ESV) information to be obtained from which diatom quality indices can be calculated to infer ecological status to rivers and lakes. Diatom DNA metabarcoding has been successfully applied for biomonitoring at the scale of national river monitoring networks in several countries around the world and can now be considered technically ready for routine application (e.g. Apothéloz-Perret-Gentil et al. 2017, Bailet et al. 2019, Mortágua et al. 2019, Vasselon et al. 2019, Kelly et al. 2020, Pérez-Burillo et al. 2020, Pissaridou et al. 2021). However, protocols and methods used by each laboratory still vary between and within countries, limiting their operational transferability and the ability to compare results. Thus, routine use of DNA metabarcoding for diatom biomonitoring requires standardization of all steps of the metabarcoding procedure, from the sampling to the final ecological status assessment in order to define good practices and standards. Following previous initiatives which resulted in a CEN technical report for biofilm sampling and preservation (CEN 2018), a set of experiments was initiated during the DNAqua-Net WG2 diatom workshop (Cyprus, 2019) to focus on DNA extraction and PCR amplification steps in order to evaluate: i) the transferability and reproducibility of a protocol between different laboratories; ii) the variability introduced by different protocols currently applied by the scientific community. 19 participants from 14 countries performed DNA extraction and PCR amplification in parallel, using i) the same fixed protocol and ii) their own protocol. Experiments were performed by each participant on a set of standardized DNA and biofilm samples (river, lake, mock community). In order to specifically test the variability of DNA extraction and PCR amplification steps, all other steps of the metabarcoding process were fixed and the preparation of the Miseq sequencing was performed by only one laboratory. The variability within and between participants will be evaluated on DNA extracts quantity, taxonomic (genus, species) and genetic richness, community structure comparison and diatom quality index scores (IPS). We will also evaluate the variability introduced by different DNA extraction and PCR amplification protocols on diatom quality index scores and the final ecological status assessment. The results from this collaborative work will not serve to define “one protocol to rule them all”, but will provide valuable information to define guidelines and minimum requirements that should be considered when performing diatom metabarcoding for biomonitoring.

Training of Specialists for the Rational Use and Protection of Aquatic Biological Resources

The environmental safety of surface waters is the main condition for preserving biodiversity, the health of the population, and sustainable developed areas. Aquatic biological resources belong to the closed system of the planet’s water space. Therefore, clean water problems and the protection of aquatic ecosystems are becoming more and more acute as civilization develops and the technological impact on the environment intensifies. Effective, rational use and management of water, land, biological resources are impossible without the training of qualified specialized specialists. Today, in modern Russia, the sectoral nature of the management of educational institutions of higher education (universities) is preserved. About a third of students in state universities study at universities of industry departments. The largest number of specialists in demand in agriculture, forestry, and water management, including nature management, technosphere safety, environmental engineering, are trained in agricultural universities. It is the agrarian branch education that effectively builds the implementation of training directions in order to provide professional assistance to business entities specializing in the use of aquatic biological resources, monitoring and environmental protection measures of water bodies, the purity of the water area (water structure, pollution, distribution of aquaculture) in various hydro-climatic conditions. The fundamental factor in the interaction of production, water use, land use, and education is the existence of an established mechanism that supports the functioning of universities as communication platforms for improving socioeconomic relations, including as a “thought factory.” The development of a strategy, forecast, assessments of the development of aquatic biological and other resources in all territories of the country is due to the demand from business entities for the training of personnel of particular professions and qualifications and research and development in the relevant field.