Water Fisheries Research Articles

Fisheries Co-management and Conflict Management in Inland Openwater Fisheries in Bangladesh

Abstract Community based management of inland openwater fisheries in Bangladesh has introduced and practiced through the Community Based Fisheries Management (cbfm) approach with partnership arrangement of government and non-government organisations, fisher communities and other stakeholders. One of the principles behind the community based fisheries management is to improve fisheries conflict management and its resolution. The implementation of the cbfm approach has experienced a significant contribution towards fishers’ conflict management. cbfm arrangement introduced fisher led, community led and women led approaches. Community based organisations (cbo s) as local institutions have been established through community participation under cbfm approach to mitigate conflict and its reducing and resolution. This paper assesses the impact of cbfm approaches on fishers’ conflict management in inland openwater fisheries in Bangladesh. It identifies the nature and causes of conflicts and develops ways of communicating good practice and reducing conflicts through fisheries co-management arrangement. This study might have policy implication to scale up cbfm approaches to promote fishers’ conflict resolution and its affective management of inland open water fisheries with a long- term commitment.

Strategic Approaches to Sustainable Inland Water Fisheries Management in Indonesia: Insights from the Draft WPPNRI-PD Fisheries Management Plan

Strategic Approaches to Sustainable Inland Water Fisheries Management in Indonesia: Insights from the Draft WPPNRI-PD Fisheries Management Plan

Unraveling Greek Inland Competitive Fishing: Historical Insights, Angler Profiles, and Motivations through Limited Data Integration in Recreational Fishing Research

This study delves into the realm of competitive sport fishing in Greece’s inland waters, where recent years have witnessed a notable surge in such activities. Despite the absence of official records, insights into the sport’s trend and the motivations and socio-demographic characteristics of anglers participating in fishing competitions were gleaned from digital data sourced from online platforms and interviews with anglers. Our findings illuminate the growing popularity of sport fishing in Greece, evident in the increasing number of fishing competitions and the burgeoning angling community. Predominantly male, anglers exhibit a strong dedication to catch-and-release practices, citing relaxation and socialization as primary motivations, with competitive aspirations also shaping their involvement. Moreover, the study highlights legislative gaps in inland water fisheries regulations, underscoring the need for updates to ensure sustainable management and to mitigate illegal activities. Additionally, there exists an opportunity to bolster anglers’ ecological awareness through targeted education initiatives. Ultimately, addressing these conclusions holds the potential to foster responsible fishing practices and contribute to the long-term sustainability of inland water fisheries.

Вміст важких металів у воді, донних відкладах та рибі водних об’єктів різного призначення Дніпропетровської області

Purpose. Assessment of the dynamics of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region. Methodology. The study on heavy metal contents in water, bottom sediments, and hydrobionts (fish) was conducted at various water bodies (Dnipro-Donbas hydraulic canal), fish ponds (ponds of PrJSC “AgroSoyuz”, PrJSC “Petrykivsky Rybhosp” and PE «Agrofirma «Nakhodka»), and multipurpose reservoirs (Dnipro reservoir, Sholokhivske reservoir) in Dnipropetrovsk region from 2015 to 2024. The determination of heavy metal concentrations (Pb, Cd, Mn, Cu, Fe, Ni, Zn) was carried out at the laboratory of the Research Center for Biosafety and Environmental Monitoring of Agricultural Resources of Dnipro State Agricultural and Economic University. The metal content was analyzed using atomic absorption spectrophotometry. The heavy metal contents were measured in four fish species (European perch, roach, Prussian carp, common carp). Sampling, data processing, and statistical analysis were conducted according to standard hydrochemical, hydrobiological, and ichthyological methods. The heavy metal contents were determined in fish muscles. Water quality was assessed according to general requirements and standards for fishery water bodies. Findings. The heavy metal contents in ecosystems of water bodies of different purposes was determined. In the sediment of ponds of PrJSC “AgroSoyuz” and PrJSC “Petrykivsky Rybhosp”, the heavy metal contents were significantly higher than in water or fish body: manganese within 41.24–68.43 mg/kg, cadmium – 0.32 mg/kg, lead 1.50–4.90 mg/kg (for ponds of PrJSC “AgroSoyuz”); manganese – 29.73 mg/kg, cadmium – 0.54 mg/kg, lead 5.72 mg/kg (for recreational pond of PrJSC “Petrykivsky Rybhosp”). For the water of these ponds, which is used for aquaculture, an excess of the content of some heavy metals – Mn, Zn, Cd - was recorded, and for the pond of PrJSC “AgroSoyuz” also Cu. Exceeding the normative heavy metal content for pond water of PE “Agrofirma “Nakhodka” was not noted. The content of some heavy metals in the water of the upper part of the Dnipro reservoir (Cu, Fe) did not meet the fishery norms. At the same time, the heavy metal contents in water and fish of these water bodies does not exceed the fishery standards for water used for fishery purposes. The heavy metal contents in the water of the upper part of the Dniprovske Reservoir (except for the Samara Bay) corresponded to fishery standards. The water in the Dnipro-Donbas hydrotechnical canal was characterized by high levels of heavy metals. Of the 6 investigated heavy metals, the maximum allowable concentrations were not exceeded only for lead (0.40 mg/dm3) The heavy metal contents in C. carpio muscles (juveniles and table fish) in different ponds of PrJSC “Petrykivskyi Rybhosp” (nursery and fattening) corresponded to fishery standards during the three years of the study (2011, 2015, 2016). In the Sholokhivske reservoir, the zinc content in C. gibelio muscles was 46.50 mg/kg, slightly exceeding the maximum allowable concentrations. Exceedances of copper and lead content were not noted. For fish from the Dnipro reservoir, the content of most heavy metals was elevated. In the meat of pelagic roach (R. rutilus), only copper content was within the normal limits (1.56 mg/kg), while all other 6 heavy metals exceeded the maximum allowable concentrations. In the meat of benthophagous Prussian carp (C. gibelio), elevated levels of accumulation of heavy metals were observed for manganese, iron, lead, and nickel, while zinc, copper, and cadmium content were within the standards. In the meat of European perch (P. fluviatilis), the highest content of heavy metals was observed for iron (80.54 mg/kg), with elevated levels observed for manganese, zinc, lead, and nickel. The obtained results indicate that the hydroecosystem of the Dniprovske reservoir, unlike other water bodies in the region, is significantly polluted with heavy metals. This is adequately reflected in the levels of heavy metal accumulation in the organisms of fish from different ecological groups - pelagic herbivores, benthophagous bottom-feeders, and predators. Originality. For the first time, the content of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region has been carried out over several years (2015–2024). Practical Value. The obtained results have theoretical and practical importance for the preparation of scientific-biological justifications for the fishery use of water bodies of various purposes in the region. Continuous monitoring of the heavy metal contents in hydrobionts is necessary to ensure food safety and the quality of raw materials and food fish products. Keywords: Dnipropetrovsk region, heavy metals, Dnipro Reservoir, Dnipro-Donbas Canal, ponds, Sholokhivske Reservoir, water, sediment, fish, accumulation of pollutants.

Transcriptomic and histologic analyses preliminarily reveal the immune-metabolic response mechanism to saline-alkaline in large yellow croaker (Larimichthys crocea)

There are large areas of saline-alkaline waters worldwide, the utilization of which would greatly enhance the development of aquaculture productivity. To elucidate the regulatory mechanisms underlying the adaptation of large yellow croaker (Larimichthys crocea) to saline-alkaline water, this study analyzed the growth performance, tissue histology, and gills transcriptome profiles of L. crocea in both seawater (CK) and saline-alkaline water (EX) groups. Growth indices statistics revealed that L. crocea can adapt to saline-alkaline water, with growth performance comparable to that of the CK group. Histological examination revealed partial cellular detachment and structural relaxation in the gills tissue of the EX group, while liver and kidney tissues appeared normal. Transcriptome analysis revealed 3821 differentially expressed genes (DEGs), with 1541 DEGs up-regulated and 2280 DEGs down-regulated. GO enrichment analysis indicated that up-regulated DEGs were enriched in terms related to metabolite production during biological activities, while down-regulated DEGs were associated with terms related to maintaining cellular activities. KEGG enrichment analysis revealed that up-regulated DEGs were enriched in pathways related to the synthesis and metabolism of amino acids and lipids, such as the PPAR signaling pathway and glutathione metabolism. The down-regulated DEGs were predominantly enriched in immune-related signaling pathways, including the Toll-like receptor signaling pathway and NOD-like receptor signaling pathway. Further analysis revealed that genes such as lipoprotein lipase A (lpla), branched-chain amino acid aminotransferase 2 (bcat2), interleukin 8 (il8), interleukin 10 (il10), and interferon regulatory factor 7 (irf7) were involved in the adaptation of L. crocea to saline-alkaline water culture conditions. This study provides a basis for understanding the adaptability of large yellow croaker to saline-alkaline water and lays the foundation for the rational utilization of fishery water resources.

How to quantify the regional effects of ocean temperature rise due to climate change: implications of Octopus maya ecophysiology on food security of the Yucatan shelf artisanal fishermen

The vital survival, maturation, and reproduction rates of Octopus maya were formulated according to the thermal preferences in each stage (juvenile and adult) and the bottom temperature of the Yucatan shelf projected from different shared socioeconomic pathways (SSPs): SSP1-5, to describe the species population growth in shallow waters. The dispersion of each individual in the population and the spread of the offshore population were incorporated with an integrodifference equation. For each SSP, the food security of the artisanal fishermen in the Western, Central, and Eastern Yucatan shelf region was analyzed based on the proposed availability, access, and utilization indices of Octopus maya as food. The analysis was complemented with an average monthly protein and income poverty indicators that this species’ shallow water fishery would have the capacity to supply by the year 2100. Although the proportion of the legally O. maya catchable population may be favored with the gradual increase in temperature in the coming years, this increase may not translate into greater food security for the artisanal fishermen who catch this species in shallow waters. Moreover, this fishery alone may not have the capacity to supply the average annual intake of 10.6 kg of protein per person recommended and maintain fishermen and their families above the income poverty line by 2100.

A geopolitical-economy of distant water fisheries access arrangements

AbstractIn recent decades, fishing fleets and effort have grown in aggregate throughout the waters of lower-income coastal countries, much of which is carried out by vessels registered in higher-income countries. Fisheries access arrangements (FAAs) underpin this key trend in ocean fisheries and have their origins in UNCLOS’s promise to establish resource ownership as a mechanism to increase benefits to newly independent coastal and island states. Coastal states use FAAs to permit a foreign state, firm, or industry association to fish within its waters. This paper provides a conceptual approach for understanding FAAs across the global ocean and for exploring their potential to deliver on the promise of UNCLOS. Illustrated with the findings from multiple case studies, we advance understanding of FAAs by developing a geopolitical-economy of access that attends to the combination of contingent and context-specific economic, ecologic, and geopolitical forces that shape the terms, conditions and practices of the FAAs shaping this persistent phenomenon of higher-income industrial fleets fishing throughout lower-income countries’ waters.

A novel tryptanthrin-based "on-off-on" probe for sequential sensing Cu2+/S2- in water samples.

Copper ions (Cu2+) and sulfide (S2-) play essential roles in many physiologies and pathologic processes. Herein, a new "on-off-on" tryptanthrin-based probe TR-1 (TR-1) has been designed and synthesized inafacileandeconomicalway. TR-1 exhibited highly selective and sensitive response to Cu2+ without any interference over 14 competitive metal ions and the detection limit downs to 24nM, which is far below the Chinese standard of fishery water quality (157nM). The 'in situ' prepared complex TR-1 + Cu2+ could also be applied to detect S2- with the detection limit of 62nM. Further, TR-1 was potentially applied for the analysis of copper ions in water samples.

ASSESSMENT OF CHEMICAL POLLUTION OF THE SURFACE WATER IN VLADIMIR

The results of studies of river water of the Vladimir city district for the content of heavy metals conducted in August 2022 are presented and the anionic-cationic composition of water is analyzed. It is shown that a number of heavy metals (lead, iron, cadmium, zinc, copper and vanadium) and ions (ammonium, magnesium, sulfates, nitrates, fluorides, phosphates) in water samples of the rivers of the city district exceed hygienic and fishery standards, which is due to both human economic activity and regional specifics of the geochemical composition of water-bearing rocks and features of groundwater functioning and feeding. The potassium concentration in water of the Nerl river, which is a drinking water source for Vladimir, corresponds to the lower threshold of physiological competence, which can affect the health of city residents if they use such water for a long time. It is shown that insufficient extraction of biogenic elements at the treatment facilities of enterprises could lead to their ingress into water bodies in concentrations exceeding hygienic and fishery standards. This in turn could contribute to the accumulation of other elements. Strict requirements for the content of chemical elements in fishery water bodies make it necessary to improve the equipment and technological schemes of purification at treatment facilities. Small rivers of cities are vulnerable and poorly protected; therefore they require special attention of environmental authorities. Being tributaries of larger rivers, small rivers form the quality of their waters. If they are used for the household and drinking purposes, they become a factor determining the health of urban residents.

Study on the status and improvement of national observer programs for Korean distant water fisheries

Study on the status and improvement of national observer programs for Korean distant water fisheries

Background levels of heavy metals in the water of Khadzhibey estuary

In the Odesa region, heavy metal contamination of fishery water bodies is a pressing problem. The accumulation of heavy metals in fish depends on the physiological and biochemical activity of the organism and the physical and chemical parameters of the water body. Most heavy metals enter the fish's body through the gills, skin, and digestive organs. Copper, zinc, and plumbum accumulate in the skin, gills, and liver, while cadmium and mercury accumulate in the kidneys. The level of heavy metal pollution in the water of the Khadzhibey estuary was measured and determined in 2022–2023. The following methods were used to determine the content of heavy metals in water: atomic emission spectroscopy using an EMAS-200 CCD instrument to determine cadmium, copper, zinc, and plumbum; cold vapor atomic absorption spectroscopy using the “Julia-2M” method to determine the content of mercury. Toxicological studies of water were carried out in the water hygiene and ecology laboratory of the Ukrainian Research Institute of Transport Medicine and at the Department of Veterinary Hygiene, Sanitation, and Expertise of Odesa State Agrarian University. The study found that the content of heavy metals in the water of the Khadzhibey estuary is not constant and fluctuates depending on the season. The maximum levels of heavy metals are observed in summer (plumbum and cadmium) and autumn (zinc, copper and mercury). It was found that cadmium, plumbum, copper, and mercury content does not exceed the maximum permissible levels for marine fisheries. The zinc content in the water of the Khadzhibey estuary exceeds the maximum permitted concentration by 2.65%. The zinc content in the studied water samples is a stress factor affecting the meat quality of common carp (Cyprinus carpio) and round goby (Neogobius melanostomus).

State of Surface and Vertical Salinity in Puttalam Lagoon during North-East Monsoon

Puttalam Lagoon which covers 226 km2 located in Sri Lanka‘s Northwest coast, plays an important role in aquaculture and lagoon capture fisheries. Kala oya and Mee oya are the major freshwater sources which empties into the Lagoon by eastern bank. Salinity variability is an important environmental variable in lagoon system that has an impact on aquaculture and aquatic resources. During the Northeast monsoon (NEM) in 2021, the spatial and vertical fluctuation of salinity in the lagoon was studied using SBE 19plus V2 CTD profiler. Field measurements show that the vertical salinity stratification in the lagoon was substantial during the study period. The lagoon has a significant spatial variability of salinity, ranging from 15 psu to 26 psu and Kala Oya river mouth has a salinity of 22 psu which impacted by freshwater and sea water circulation. The Salinity stratification in eastern section of the lagoon where the Kala Oya and Mee Oya streamflow reach is observed with surface salinity of 15 psu. During the NEM season, the average discharge of Kala Oya and Mee Oya to the lagoon was 10.8 m3/s and 9.4 m3/s, respectively, with a mean monthly precipitation of 48.89 mm. Fresh water from the Kala and Mee oya rivers flows into the lagoon during the season, while low evaporation and significant rainfall led the salinity to decline during the wet season, influencing the structure and function of lagoon ecosystems. The study reveals that a significant area of the lagoon is covered by the 20-30 psu salinity range, which is more appropriate for brackish water fisheries, particularly for shrimp and prawns during NEM. 
 Keywords: Salinity, CTD profiling, Northeast Monsoon, Freshwater

Spatio-temporal variability of fishing habitat suitability to tuna purse seine fleet in the Western and Central Pacific Ocean

Understanding the spatial distribution of fishing activity is important for ecosystem-based fisheries management.The dynamic vessel trajectory information provided by Automatic Identification System (AIS) together with local remote ocean environment data, provide an opportunity for new technologies to enable improvements in fisheries management.The spatio-temporal and variability to tuna purse seine fleet suitable fishing were evaluated based on fishing effort from AIS by constructing an integrated habitat suitability index (HSI), which weight of variables were determined with boosted regression trees (BRT) model. The results show that the fishing activity tuna purse-seine fleet and catch data from the Western and Central Pacific Fisheries Commission (WCPFC) have the same spatial distribution.The tuna purse seine fleet operation concentrate in EEZ area of the Pacifc Island countries and has seasonal environmental preferences. The fishing habitat suitability can be characterized by a few environmental factors. The HSI model had good capacity to predict habitat suitability to tuna purse seine fleet for mostly catch and fishing effort located in the suitable area. The suitable fishing areas showed significant seasonal changes and low utilization of the available environmentally suitable fishing habitat in each month. The most stable suitable area located in the New Guinea Offshore latitudinal region, may be experiencing high tuna purse-seine fishing pressure throughout the year. The research could help to improve the scientific and effective management of distant water fisheries under limited regulatory capacity.

Ecological approach to fish productivity preservation prospects of Rostov region water bodies

Ensuring food availability in such volumes that, without taking into account imports, the availability of foodstuffs is not lower than the world average consumption norms requires the expansion of the range of enterprises producing food products. Given the need to follow the Strategy for the Development of the Fishery Complex of the Russian Federation adopted in November 2019, covering the period until 2030, it should, in addition to measures including infrastructure reorganization, increasing catch and industrial production of fish products, increasing processed fish products range, it is necessary to consider the importance of fishery water bodies’ state and assess their fish productivity level. Under high anthropogenic impact on the water bodies of the Nizhnedonsky basin conditions, a hydrobiological situation is formed, when the increase in phytoplankton content indicates not an increase in fish productivity, but eutrophication high degree, while overgrowing of the water body is stimulated. Thus, the most popular fish productivity determination method, associated with food base level determination, will not give a sufficiently accurate water body’s fishery potential representation, as the increase in biomass level creates less favorable conditions for the vital activity of commercial fish species.

Water Salinity in Agriculture: Analyzing Irrigation Water Quality for Farmers

The primary aim of this study is to assess irrigation water's salinity levels and categorize them as regular, slightly to moderately saline, or severely saline, using the salinity parameters established by Ayers and Westcot as a reference. This practice plays a substantial role in global agriculture, accounting for 20% of total cultivated land and contributing 40% of the world's food production. It falls under the classification of water usage known as Class C, which encompasses Fishery Water for the propagation and growth of aquatic resources, Recreational Water Class II for boating and similar activities, and Agriculture, including irrigation and livestock watering. This classification underscores irrigation water's profound influence on agriculture as a whole. Salinity, often considered one of humanity's earliest environmental challenges, is paramount. Excessive salinity in agriculture, particularly in the context of rice (Oryza sativa L.) cultivation, a staple crop that nourishes half of the global population, poses a formidable threat. High salinity levels can potentially hinder plant growth, reduce crop yields, and compromise the quality of agricultural products. This research seeks to illuminate the critical issue of salinity in irrigation, specifically focusing on its implications for rice cultivation, which plays a pivotal role in global food security. By delineating the salinity status of irrigation water, it aims to provide valuable insights into the challenges confronted by agricultural communities and lay the groundwork for informed decision-making in sustainable agriculture.

Автоматизированная станция нейтрализации шахтных и подотвальных сбросов от ионов тяжелых металлов

The article describes a technological solution implemented as a fully automated station for neutralization of industrial wastewater that contains heavy metal ions, for example, water generated during mining of non-ferrous metal ores using underground or surface mining systems. This technology makes it possible to purify acidic wastewater from toxic metal ions, e.g. copper, zinc, iron to match the maximum permissible concentrations for fishery water bodies. The essence of the technology consists in saturation of the lime milk fed into the stream of adit effluents with carbon dioxide pumped together with the atmospheric air or produced by combustion of carbon-containing fuels. The presence of carbonate groups facilitates formation of practically insoluble dihydrocarbonates of heavy metals, particularly those of copper.

A study on improving the IUU Fishing Index of Korea's distant water fisheries

A study on improving the IUU Fishing Index of Korea's distant water fisheries

Application of The Completely Random Design Statistics Method For Analysis of Different Filter Types In Fresh Water Fish Pool Water Recirculation System

In meeting their daily water needs (bathing and washing), the majority of the people of South Kalimantan (South Kalimantan) have been using river water and peat well water, as is the case for fresh water fisheries. However, the water used is cloudy and smells because it is water that is polluted by household waste, and of course it shows the quality of the water that is still being debated for the process of fish cultivation. In the process of cultivating freshwater fish, the standard mechanism is still used, namely by making tarpaulin ponds for fish ponds and river water as a medium for fish cultivation and the process of providing feed. In the process there are several things about water quality and conditions, and several other issues, namely about water circulation, temperature, humidity, pH and oxygen regulation of fish pond water. Fish excrete waste from leftover feed and metabolism which contain lots of ammonia (Effendi, 2003). Fish excrete 80-90% of ammonia through osmoregulation processes, feces and from urine. To produce quality pond water as a medium for fish cultivation, it is necessary to have a proper and good water filter. This study aims to obtain the best filter substrate in increasing the growth and survival of freshwater fish fry reared using polluted river water in a tarpaulin pond with a recirculation system. The filter method used in this study was an experimental method using one factor Completely Randomized Design (CRD) with four treatment levels and three replications. The treatments applied were P0 = Zeolite, Charcoal, Japmate, Bio Foam, P1 = Bamboo, Charcoal, Japmate, Bio Foam, P2 = Bioball, Charcoal, Japmate, Bio Foam and P3 = Bioring, Charcoal, Japmate, Bio Foam. The resulting data were analyzed for analysis of variance (ANOVA), then continued using the BNT test with 95% and 99% confidence intervals. From the results of the study, the measurement results obtained were for the specific growth rate test (SGR) of 1.15%, the survival test (SR) of 86.66% and the feed conversion ratio test (FCR) of 3.10%. While the supporting parameters are water quality, namely the results of water quality, namely, temperature 28.1 – 30.3 0C, pH 7.4 – 8.1, DO 5.24 6.53 mg/L, NH3 0.06 – 0.40 mg/L, NO2 0.056 – 0.90 mg/L and NO3- 0.28 – 0.190 mg/L. In addition to producing filter products that can support SGR, SR and FCR in freshwater fish, it is hoped that this research will also produce scientific paper outputs that will be published in International Conferences/International Journals and become part of the Study Program's Coursebook for the Accounting Department. Computerized Poliban Accounting and can be applied in the community through the Community Service program

REHABILITATION OF MAN-MADE FORMATION OF ABANDONED COPPER PYRITE DEPOSITS ON THE EXAMPLE OF LEVIKHINSKY MINE (MIDDLE URALS)

Link for citation: Rybnikova L.S., Rybnikov P.A., Navolokina V.Y. Rehabilitation of man-made formation of abandoned copper pyrite deposits on the example of Levikhinsky mine (Middle Urals). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 8, рр. 137-150. In Rus. The relevance of the research is related to the need to rehabilitate of abandoned copper pyrite deposits affected by acid mine waters and justify measures to clean up the existing clarification pond. The main aim is to study the sludge composition and justify the measures to reduce the environmental load on the hydrosphere. Objects: clarification pond and neutralization sludge of the Levikhinsky copper pyrite mine acid mine waters. Methods. Laboratory studies of water and bottom sediments were carried out using atomic emission and mass spectral analysis; methods of flame emission spectrometry, flame atomic absorption, photometric method with Nessler's reagent, titrimetric, mercumetric and potentiometric methods; mass spectrometry with ionization in inductively coupled plasma and gravimetric method. Results. Sludge samples are dominated by sulfates (gypsum and bassanite), iron oxides and hydroxides (goethite), carbonates (calcite), clay minerals (mainly hydromica) and chlorine-containing salts (carnallite). The chemical composition of the sludge is dominated by oxides of iron, sulfur and calcium. The analysis of water and acid extracts showed that up to 24 elements belonging to hazard classes 2, 3 and 4 can be leached from the sludge in concentrations exceeding the maximum allowable values for fishery water bodies. Several options for the use of sludge from the clarification pond were analyzed: reclamation of waste rock dumps and substandard ores; backfilling of mined-out area of quarries; production of building materials; extraction of components; storage of sludge in geotubes (Geotube). The most rational is the disposal of sludge as the production of building materials on the basis of a public-private partnership, the implementation of which will allow the state and the private sector to derive mutual benefit.

Runoff of Water and Its Quality under the Combined Impact of Agricultural Activities and Urban Development in a Small River Basin

The basin of the small river studied here (the Vezelka River, Belgorod Oblast of European Russia) is located within an urban area (22% of the basin). This circumstance determines its specificity as an object of synergetic anthropogenic impact. The purpose of the work was to develop and test approaches to the integral assessment of the hydroecological situation both in the watershed and riparian zones based on hydrological, hydrochemical, and hydrobiological data and estimates of soil erosion, river water quality, and the pollution of river bottom sediments. The selection of the Vezelka River and its watershed for the study was due to the presence there of two water intakes for a town with a population of 2439 people per sq. km, repeated bottom deepening in the riverbed, and the fact that there is a single regional small-river hydrological station (although there are 567 rivers < 25 km long in Belgorod Oblast). Analysis for 1951–2021 showed a steady decline in water discharge since 1991; thus, over the past three decades, the discharge has decreased by 2.4 times. The reduction in the length of the river network of the study region by 38% over the past 250 years and the assignment of water (at 10 gauging stations) to 3–4 quality classes (extremely and heavily polluted) indicated the exhaustion of the possibilities for the self-purification of the river water. These estimates for large and medium rivers were clearly confirmed by the investigation of the water in the small river studied. In the summer low-water periods, the maximum allowable concentrations in fishery water bodies were exceeded by 2–10 times in terms of Cu, Fe, ammonium, oil, and biochemical oxygen demand. The reconstruction of the floodplain–channel subsystem of river–valley landscapes was substantiated as the final stage of the concept of basin nature management, replacing the continuous deepening of the channel without proper erosion control measures in the watershed area and the organization of buffer zones along the river banks.