Промысел и состояние запасов гаммарид в озерах Курганской области в 2000-2022 годах

The long-toed crayfish Pontastacus leptodactylus Eschscholtz is one of the few invertebrates of freshwater reservoirs of the Altai Territory, representing a promising object of fishing. This paper provides an overview of changes in the state of cancer populations in commercial reservoirs of the Altai Territory in the period 2010-2021. The analysis of the dynamics of the main parameters reflecting the quantitative characteristics of cancer populations was carried out. The trend of decline in commercial stocks of cancer is traced, the dynamics of production (catch) of cancer by organized fishing is presented. The characteristic of the main causes of changes in commercial stocks of cancer, both natural and anthropogenic significance, is given.

This article is dedicated to issues of improving the land reclamation and water management sector of the agro-industrial complex at the present stage of development of the water industry. This is dictated by the current needs of the socioeconomic development of the Russian Federation, dynamic climate change, and active progress in the field of information and digital technologies, as well as by new opportunities for mathematical modeling and software and the development of production and construction technologies, structures, and materials. The attention of the authors is focused on the role of climate change in the deterioration of agricultural conditions, which is confirmed by the results of a statistical retrospective analysis of observational data from weather stations in the Lower Volga region, the Ural basin, the Far East, and southern Western Siberia. Forecast calculations of water supply (consumption by the population, land irrigation, animal husbandry) for 2035 show that all regions of the Lower Volga and the south of Western Siberia, as well as some regions of the Far East, will experience a lack of water resources for irrigating crops. In the current climatic, economic, and social conditions, the innovative development of the water management complex of the Russian Federation necessitates elaborating a state-of-the-art strategy for the sustainable development of the land reclamation and water management complex.

Thermokarst lakes in the Western Siberian Lowland (WSL) are major environmental factors controlling organic carbon and trace metal storage in inland waters and greenhouse gas emissions to the atmosphere. In contrast to previously published research devoted to lake hydrochemistry, hydrobiology, sedimentary carbon, and processes controlling the lake total dissolved (<0.45 μm) solute composition, the colloidal forms of organic carbon (ОC), and related elements remain poorly known, especially across the permafrost gradient in this environmentally important region. Here we sampled 38 thermokarst lakes in the WSL, from the continuous to the permafrost-free zone, and we assessed both the total (<0.45 μm) and low-molecular-weight (<1 kDa) concentrations of 50 major and trace elements using conventional filtration and in situ dialysis. We aimed at quantifying the relationships between the colloidal content of an element and the lake surface area, permafrost coverage (absent, sporadic, isolated, discontinuous, and continuous), pH, and the concentrations of the main colloidal constituents, such as OC, Fe, and Al. There was a positive correlation between the lake area and the contents of the colloidal fractions of DOC, Ni, rare earth elements (REE), and Hf, which could be due to the enhanced mobilization of OC, trace metals, and lithogenic elements from silicate minerals in the soil porewater within the lake watershed and peat abrasion at the lake border. In all permafrost zones, the colloidal fractions of alkalis and alkaline-earth metals decreased with an increase in lake size, probably due to a decrease in the DOC concentration in large lakes. There was an increase in the colloidal fractions of DOC, Fe, Al, trivalent and tetravalent trace cations, Mn, Co, Ni, As, V, and U from the southern, permafrost-free zone to the northern, permafrost-bearing zones. This observation could be explained by an enhanced feeding of thermokarst lakes by suprapermafrost flow and the thawing of dispersed peat ice in the northern regions. Considering the large permafrost gradient of thermokarst lakes sampled in the present study, and applying a space-for-time substitution approach, we do not anticipate sizable changes in the colloidal status of DOC or major or trace elements upon climate warming and the permafrost boundary shifting northwards. For incorporating the obtained results into global biogeochemical models of OC, metal micronutrients, and toxicant migration in the permafrost regions, one has to consider the connectivity among lakes, soil waters, and rivers. For this, measurements of lake colloids across the main hydrological seasons, notably the winter period, are necessary.

Due to the decline in fish stocks in Brazil, mainly in the Amazon Basin, the Closed Fishing Season Law was implemented to help fisheries recover and protect fish habitat. Tambaqui ( Colossoma macropomum ) is one of the main overexploited fish species and there is concern about its decline in many Amazonian rivers. Therefore, in order to investigate the effectiveness of the Closed Fishing Season Law as it applies to tambaqui, seizure data compiled by IBAMA (Brazilian Institute of Environmental Protection) was analyzed for the period 1993 to 2012 (20 years) for the Negro, Solimoes and Amazonas rivers. Although the results of this study showed variations in the volume of tambaqui seizures among the three different rivers analyzed over a 20-year period, these variations were small in comparison to the differences found between the 10-year periods before and after implementation of the Closed Fishing Season Law. Overall, there was a 24.4% decrease in the volume of tambaqui seized after implementation of the Law, which can be attributed to a number of possible reasons: 1) reduction of tambaqui stocks in the area of study; 2) occurrence of great floods and dry periods influenced by the natural phenomena El Nino and La Nina, which strongly affected fish stocks in 2002-2003 and 2009, respectively; 3) poor enforcement of regulations, due to reductions in IBAMA personnel and; 4) difficult to patrol such a large area, including many remote locations. However, notwithstanding the noted overall decrease, the results suggest that implementation of the Closed Fishing Season Law with its corresponding compensation payments to fishers did not end up dramatically improving the protection of tambaqui stocks and may have even encouraged more people to enter into the fishery to benefit from the payments. Keywords: Fishery stocks; fisheries; closed season compensation.

Aim. To identify the reasons for the decline of fish stocks in the Caspian sea. Location . The Caspian sea. Methods . When adverse effects of multiple abiotic factors, the other part indicates the important role of fisheries. How fair this point of view will try to answer in this paper. Consider long-term changes in the average water temperature in the Northern Caspian sea. Results . Considered abiotic and biological factors ( prey base) productivity of the Northern Caspian sea could cause catastrophic ( tenfold) reduction of fish stocks. Evidence of this is shown in table. 2 which shows that external factors do not provide a clear correlation with the yield of fish, more important are the internal factors related to the impact of fishing. Main conclusions . You should pay very close attention to human factors and in particular on the volume of catch, location and time fishing and more time to assess how rational our modern craft.

When forests are cleared for agricultural crops, the carbon stored originally in trees is oxidized and released to the atmosphere, either rapidly if the trees are burned or slowly if they are left on the ground to decay. Similarly, the organic matter of soil is reduced through cultivation. Such reductions in the carbon stocks of terrestrial systems occur with the harvest of forests for wood and with the clearing of forests for cropland, pasture, or other uses. On the other hand, the regrowth of forests following harvest, the abandonment of agriculture, or the establishment of plantations increases the storage of carbon on land, both in vegetation and in soils. The balance between the clearing and regrowth of forests is the major factor in determining changes in the net storage of carbon in terrestrial systems. Non-forested systems can also lose or accumulate carbon, such as when grasslands are converted to agriculture; however, the changes in carbon per unit area are much smaller than for forests.

CO2 and CH4 fluxes were measured from three small wetland lakes located in the middle taiga and forest tundra zones onWest Siberian Lowlands (WSL), the world’s largest wetland area. Fluxes were measured during summer 2005 using floating chambers and were validated against the thin boundary layer model based on the relationship between gas exchange and wind speed. All studied lakes were supersaturated with CO2 and CH4, and acted on a seasonal basis as sources of these greenhouse gases to the atmosphere. Daily mean CO2 fluxes measured with chambers ranged from near the zero to 3.1 g CO2 m-2 d-1 and corresponding CH4 fluxes from 1.1 to 120 mg CH4 m-2 d-1. CH4 ebullition (0.65–11 mg CH4 m-2 d-1) was detected in two of the lakes. Total carbon evasion from the studied lakes during the active season was 23–66 g C m-2, of which more than 90% was released as CO2-C. The carbon loss per unit area from the studied lakes was of similar magnitude as previously reported values of net carbon uptake of Siberian peatlands. This emphasizes the importance of small water-bodies in the carbon balance of West Siberian landscape.

Aim . To aim is to assess stocks and the fisheries of aquatic biological resources in the western part of the middle Caspian Sea and perspectives for the use of their resource potential. Methods . On the basis of the literature sources and our own data on the fish inventory in the western part of the Middle Caspian, we discuss possible reasons for emerging environmental, economic and other problems in the use of biological resources. Results. The main negative factors are the large-scale poaching, resulting in a catastrophic reduction in stocks of sturgeon and other valuable fish species of the Caspian Sea, a natural penetration of alien organisms (Mnemiopsis) and overfishing of some species. The potential danger is large-scale development of oil and gas fields in the Caspian Sea, which can lead to even worse situation for the biological resources of the sea. Conclusions. In order to preserve the biological resources of the sea it is necessary to create conditions for steadily developing fishing and fish processing enterprises, thus ensuring the satisfaction of the constant demand for fish products and an increase in the revenue base of the budget and the well-being of the Russian population.

The Aral-Caspian basin plays a crucial role in the formation of commercial fish stocks, which have been de-clining in recent years due to a decrease in the efficiency of natural reproduction due to an unfavorable hydrological regime. The results of studies carried out in 2019-2023 in the lower reaches of the Ural River on the influence of the hydrological regime and the number of producers in spawning areas on the reproduction efficiency are presented using the example of semi-migratory fish: roach, bream, walleye, carp, asp. It is shown that over the past 10 years, low- and medium-water years with a flood flow volume of 2-3 km3 prevailed, and only 3 years were high-water (more than 4 km3). Unfavorable years in terms of water content had a negative impact on the efficiency of fish reproduction in the Ural River, which led to a decrease in the number of offspring and, as a result, a reduction in commercial fish stocks in the region. It was found that in high-water years, even with a low number of producers in spawning grounds, the number of life-resistant sloping juveniles of the studied fish species was greater than in low-water years with a high number of producers. In the course of research, it was found that unfavorable hydrological conditions in the Ural River had a lesser impact on the roach and bream, and the number of juveniles of the latter has increased over the years. Commercially valuable walleye, asp and carp are in a depressed state, the number of recorded juveniles of which was ten times less than bream and roach. The state of reproduction of the carp is alarming, the number of juveniles of which reached a critical level in low-water 2019. According to the results of the study, it is recommended to implement a number of comprehensive measures of fisheries reclamation to improve the state of commercial stocks in the Ural-Caspian region.

The Sub-Regional Office of the Caribbean of the Food and Agriculture Organization (FAO-SLC) facilitated the collation of information on sustainable production practices in Barbados, Antigua and Barbuda, Dominica, St. Kitts/Nevis, St. Vincent and the Grenadines, Grenada and St. Lucia. The study, carried out by the Caribbean Agricultural Development and Research Institute (CARDI) on behalf of the FAO, aimed to identify the use of some of the 'tried-and-tested' methods in order to promote them by making them available to the wider agricultural community in the Region. This is in keeping with FAO's sustainable crop production intensification (SCPI) objective, which aims to increase crop production per unit area, taking into consideration all relevant factors affecting productivity and sustainability, including social, political, economic and environmental impact. In the current study, 'sustainability' included environmental, financial and socio-economic elements. Current practices were determined via onfarm observation and inquiry, as well as by reviewing marketing and legislative protocols. Activities of over 2000 producers were drawn from individual interviews, field inspections, Extension Officer reviews, and structured group sessions. Whilst several practices were seen to be endemic and common to all seven countries, there were subtle inter- and intra-island differences. Results indicate that in all countries, sustainability was more commonly defined in terms of environmental aspects by way of soil and water conservation, and ' sustainable' practices dealt with land clearing, erosion reduction and soil improvement. Additionally, water conservation as opposed to rainwater harvesting and storage was a central pursuit. Appropriate cropping patterns and other farming practices were largely determined by geography. There was a reasonable level of understanding of the benefits of biodiversity as related to sustainability. Interestingly, there were some practices which were not as widespread that could be expanded, and others that were widespread but not effectively executed. Several recommendations are presented based on the amalgam of practices recorded, on the areas of land use, soil quality, water use and reuse, environmental sustainability, and financial sustainability.

New ass. Cladophoro fractae–Stuckenietum chakas­siensis Kipriyanova ass. nov. hoc loco, referred to the alliance Сladophoro fractae–Stuckenion chakassiensis Kipriyanova all. nov. hoc loco, to the order Ruppietalia maritimae J. Tx. ex Den Hartog et Segal 1964 and to the class Ruppietea maritimae J. Tx. ex Den Hartog et Segal 1964 was described in Siberia. Nomenclature type (holotypus) — relevé 3 (author′s number 5.3) in Table. Dominating diagnostic species is Stuckenia chakassiensis (Kaschina) Klinkova (Flora Nizhnego Povolzhiya, 2006). (Synonyms are Potamogetonpectinatus L. subsp. chakassiensis Kaschina in Krasnob. et Safonova, 1986, Novoe o Fl. Sibiri: 245. — P. chakassiensis (Kaschina) Volob. 1991, Sibir. Biol. Zhurn. 5: 75. — P. chakassiensis var. tenuior Volob. 1993, Sibir. Biol. Zhurn. 3: 57. — P. intramongolicus Ma, 1983, Acta Bot. Bor.-Occid. Sin. 3(1): 8, nom. inval. — P. acifolius Ma, 1983, Acta Bot. Bor.-Occid. Sin. 3(1): 8, nom. inval. — Stuckeniaintramongolica (Ma) Tzvel. 1999, Bot. Zhurn. 84(7): 111, nom. illeg.). The species richness (data of fifteen relevés) is 1–4 per relevé, which is explained by relatively high salinity values. A total of 8 species were registered in association communities. Communities with total cover 20–95 %, occupy quite large (from 20 to more than 100 m2) areas in the studied lakes. The main ­layer — submerged plants — is made by shoots of Stuckenia chakassiensis. There are other species with a wide range of halotolerance (Cladophora species), as well as brackish and saline water species (Ruppia maritima, Chara aspera, C. canescens, C. altaica) and Althenia orientalis, Ruppia drepanensis, R. cirrhosa, Lamprotamnium papulosum, which are much rarer in Western Siberia. Other layers are not expressed, except for the emergent plants represented by reed on the border of belts of submergent and emergent vegetation. Communities of associations were observed only in the brackish (oligohaline, mesohaline, polyhaline) waters of the various classes and groups: mainly sodium-chloride in the south of West Siberia, and sodium-bicarbonate in East Siberia. Not too often they were found in sodium-sulfate and magnesium-bicarbonate waters. Salinity range of association in Transbaikalia was 1.11–9.57 g/dm3. Maximum salinity for Stuckenia chakassiensis communities in the Novosibirsk region was 10.32 g/dm3, in the lakes of Khakassia — 28.8 g/dm3. The pH values varied from 6.55 to 10.50. Special publications (Kipriyanova et al., 2016, 2017) are devoted to a description of the hydrochemical preferences of the S. chakassiensis and some other species of the genus Stuckenia in the lakes of Transbaikalia. According to the obtained data in the brackish waters of the lakes of East Siberia, S. chakassiensis forms thickets with rather high productivity (up to 517.4±89.51 g/m2 abs. dry weight) (Kipriyanova et al., 2017). The association′s area of distribution appears to coincide with the range of the species, which is a southern part of Siberia (Kurgan Region, Novosibirsk Region, Altai Territory, the Republic of Khakassia, the Republic of Buryatia, Trans-Baikal Territory), northern Kazakhstan, northern China, Mongolia, and rarely — the South Eastern Europe: Volgograd Region (Chernyshkovsky district, in the estuaries and lakes of the Tsimlyansky sand massif near the hamlets Tormosin and Morskoy ) (Flora of the Lower Volga region, 2006; Krasnaya..., 2006) and in the Caucasus ­(Tzvelev, 1990). The association quite logically fits into the class Ruppietea and the order Ruppietalia. In addition to the actual cenoses of different Ruppia species, the communities of other aquatic halotolerant plants, such as the association of emergent plant Eleocharitetum parvulae (Christiansen 1934) Gillner 1960, the bryophyte cenoses Rielletum helicophyllae Cirujano et al. 1993, Rielletum notarisii Cirujano et al. 1993 may be included into this class (Rivas-Martínez et al., 2002; and others). Some researchers place into this class the communities of halotolerant charophytes of the Charion canescentis Krausch 1964 alliance, and the ass. Ranunculetum baudotii Br.-Bl. in Br.-Bl. et al. 1952 (Berg et al., 2014). The input of the ass. Cladophoro fractae–Stuckenietum chakassiensis to the Ruppietea class corresponds to principles and methods of the Braun-Blanquet approach (Braun-Blanquet, 1964), since the diagnostic species of the new association is accompanied with different species abundance in the brackish and saline waters: Ruppia maritima, Chara canescens, C. altaica, as well as species with a wide range of halotolerance — Cladophora fracta and others. The character diagnostic species of Сladophoro fractae–Stuckenion chakassiensis alliance are the species specific for continental brackish and saline waters of forest-steppe and steppe zones of Asia such as Stuckenia chakassiensis, S. macrocarpa, Chara altaica.

This scientific study aimed to assess the dynamics of land cover and green biomass in the Aral Sea region observed between 2000 and 2024 using remote sensing and geoinformation technologies. For this purpose, a total of 21 cloud-free scenes (approximately 35 GB in size) from MODIS, Landsat, and Sentinel-2 sensors were processed using Sen2Cor atmospheric corrections and Fmask masking in Google Earth Engine. NDVI and LAI layers were developed based on seasonal median composites. The equation Biomass = 7.63 × e^(2.85 × NDVI) was determined between NDVI and field-measured biomass data, with R² = 0.79 and RMSE = 3.4 t/ha. The final result was a 10 m (UTM 42N) resolution overlay of NDVI, LAI and biomass layers over different land cover classes, clearly expressing the rate of degradation in the area, the growth and decline trends of biomass in reclaimed areas and irrigated arming zones. The research results serve as an important analytical basis for planning water-saving technologies, environmental monitoring and developing regional spatial planning strategies.

Peatlands are a major source of dissolved organic carbon (DOC) for inland waters in Western Siberia. Continuous hydrological and hydrochemical monitoring of these peatlands is essential for understanding the global carbon cycle. We investigated a pristine ombrotrophic bog in Western Siberia to determine the links between seasonal hydrological changes and DOC quantity and quality. Specifically, we analysed water table fluctuations, DOC concentrations and spectral characteristics (SUVA 254 , E2:E3 and E4:E6 ratios). Our findings indicate that each peatland ecosystem exhibits distinct seasonal hydrochemical changes. The driest ecosystems (ryams) feature water with the highest DOC concentrations, characterised by high aromaticity and large molecular size, whereas the wettest ecosystems (pools) display the opposite trend. Surprisingly, the stream, which collects water from the entire peatland catchment, exhibits unique properties in that its DOC concentration is similar to that of wet ecosystems, while its spectral features more closely resemble those of dry ecosystems. Therefore, peatland ecosystems act as complex biogeochemical systems, modulating both the concentration and quality of dissolved organic carbon (DOC) based on prevailing environmental conditions.

Abstract. Greenhouse gas (GHG) emission from inland waters of permafrost-affected regions is one of the key factors of circumpolar aquatic ecosystem response to climate warming and permafrost thaw. Riverine systems of central and eastern Siberia contribute a significant part of the water and carbon (C) export to the Arctic Ocean, yet their C exchange with the atmosphere remains poorly known due to lack of in situ GHG concentration and emission estimates. Here we present the results of continuous in situ pCO2 measurements over a 2600 km transect of the Lena River main stem and lower reaches of 20 major tributaries (together representing a watershed area of 1 661 000 km2, 66 % of the Lena's basin), conducted at the peak of the spring flood. The pCO2 in the Lena (range 400–1400 µatm) and tributaries (range 400–1600 µatm) remained generally stable (within ca. 20 %) over the night–day period and across the river channels. The pCO2 in tributaries increased northward with mean annual temperature decrease and permafrost increase; this change was positively correlated with C stock in soil, the proportion of deciduous needleleaf forest, and the riparian vegetation. Based on gas transfer coefficients obtained from rivers of the Siberian permafrost zone (k=4.46 m d−1), we calculated CO2 emission for the main stem and tributaries. Typical fluxes ranged from 1 to 2 gCm-2d-1 (>99 % CO2, <1 % CH4), which is comparable with CO2 emission measured in the Kolyma, Yukon, and Mackenzie rivers and permafrost-affected rivers in western Siberia. The areal C emissions from lotic waters of the Lena watershed were quantified by taking into account the total area of permanent and seasonal water of the Lena basin (28 000 km2 ). Assuming 6 months of the year to be an open water period with no emission under ice, the annual C emission from the whole Lena basin is estimated as 8.3±2.5 Tg C yr−1, which is comparable to the DOC and dissolved inorganic carbon (DIC) lateral export to the Arctic Ocean.

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