Summer-autumn Period Research Articles

Long-term dynamics of the heterоtrophic bacterioplankton development in the mouth of the Usinsky bay of the Kuibyshev reservoir

Data of our long-term observations of the bacterioplankton development in the mouth section of the Usinsky bay (the Kuibyshev reservoir) during the summer–autumn periods are presented. The total abundance of heterotrophic bacterioplankton varied within (1.61–7.44)×106 cells/mL, the biomass was 39.01–249.53 µgC/L, which corresponds to III–V water quality classes. Between 2010 and 2017 the total abundance of heterotrophic bacterioplankton was nonmonotonically decreasing, and since 2021 its significant increase is recorded. Among heterotrophic bacteria, single freefloating cells predominated, mainly cocci and coccobacilli, and the proportion of rod-shaped cells increased during cyanobacterial bloom. Picocyanobacteria and picodetritus particles were almost always present in plankton, but their average contribution to the total organic carbon of picoseston was insignificant.

Seasonal changes in the physicochemical characteristics of atmospheric aerosol at the research station “Ice Base Baranova Cape” (Severnaya Zemlya archipelago)

Since 2017 we have carried out aerosol sampling at the research station “Ice Base Baranova Cape” (Novaya Zemlya Archipelago) with the purpose of studying the variations in aerosol physicochemical characteristics: the concentrations of ions, microelements, organic and elemental carbon (ОС and ЕС), as well as the isotopic composition of carbon δ13C in the aerosol. The average summed concentrations of ions throughout the period of measurements were 1,99 μg/m3, the concentrations of elements were 51,1 ng/m3; and those of ОС and ЕС were 398 and 25 ng/m3, respectively; the isotopic composition of carbon δ13C was–27.6 ‰. The main contribution (73 %) to the ion composition of atmospheric aerosol is due to “marine” ions Na+ and Cl-, and the contribution to the elemental composition is due to terrogenic Fe and Al (71 %). The large enrichment coefficients (with respect to Na+ in sea water) were manifested for ions SO 2-, K+, and Ca2+. Aerosol enrichment by these ions is the largest in the warm period. In the aerosol elemental composition, we identified large enrichment coefficients (with respect to Al in the Earth’s crust) in elements Se, Sn, Sb, Mo, As, Zn, Cu, Cr, Pb, and Cd, indicating their technogenic origin. The nearest sources of aerosol enrichment by technogenic elements are plants for mining and processing mineral resources in the Taymyr Autonomous Okrug. The statistical generalization of the multiyear data allowed us to calculate for the first time the annual average behavior of the chemical composition of aerosol in the study region. With respect to the seasonal variations, the ions and elements can be divided into three groups: 1) with winter maximum (Na+, Cl-, Mg2+, Br-; Se, Cd, V, Co, As); 2) with summer (PO 3-, NH +, CH SO3-, F-) or autumn (Al, Ti, Li, Sr, Fe, Zn, Ba, Ni) maximum; 3) with poorly defined or indefinite variations in other ions (NO -, K+, SO 2-, Ca2+) and elements (Cu, Pb, Mo, W, Sn, Cr, Sb, Mn). As most of the other characteristics, the annual behaviors of the ОС and ЕС concentrations are characterized by the general maximum in the winter-spring period. In addition, a second maximum is manifested in the ОС content in the summer-autumn period. The average monthly carbon isotopic composition in the aerosol varies in the range from –28.3 ‰ (February) to –27.3 ‰ (May).

Application of artificial neural network for description of the Earth remote sensing data to identify natural habitats used by European elk, Alces alces (Linnaeus, 1758), in autumn-winter period 2023

The paper presents the results of using neural networks of pixel-by-pixel image classification to decipher multichannel space images obtained by the Landsat 8 satellite. Natural habitats were identified based on differences in phytocenotic characteristics of land areas. The level of use of areas by elk was determined by the occurrence of elk presence indicators, which were the density of winter excrement piles (in spring) and the abundance of winged forms of the monoxenous ectoparasite of elk, Lipoptena cervi (Linnaeus, 1758), as measured by the number of individuals attacking the census taker (in the summer-autumn period). The material that forms the basis for deciphering was obtained by the route census method in different areas of the Leningrad Province. High values of the measured parameters were recorded in reforestation areas, in wet pine and birch forests, in aspen forests, on the edges of raised bogs and in overgrown fields – typical elk winter feeding habitats. Based on the data on the maximum values of the measured parameters, a positive correlation was established for the first time between the abundance of winged forms of L. cervi and the physiological activity of the host (the density of the piles of “winter” excrement). The paper also provides a valid reference to the material of schematic maps developed for a part of the territory of the Leningrad Province and Saint Petersburg. The scheme of the use of areas by elk is compiled on the basis of the relative index calculated from the measured parameters of the survey. Field observation areas and territories close to them were most reliably identified (90–95% accuracy). For areas not covered by field observations, the paper provides comments on the main inaccuracies of the schemes and the reasons for the identified discrepancies, based on an analysis of literary sources devoted to similar research topics. The results of the study indicate that the frequency of attacks of winged forms of L. cervi can be used as an additional criterion for assessing the stationary preferences of elk in the winter period using information on the period of active flight, and the decoding method mentioned in the paper can be used in limited areas of specific territories, including reserves, areas of hunting farms and district forestries.

Profitability, greenhouse gas emissions and feed-food competition of strategies to exploit compensatory growth in Uruguayan weanling-to-beef systems

This study evaluates nutritional and management strategies aimed at exploiting compensatory growth (CG) in weanling-to-beef systems in Uruguay. The evaluation encompassed productivity, economic viability, and environmental impact. The Grange Beef System Model, augmented with Uruguayan national technical coefficients, was used. Four weanling-to-beef systems were modeled: 1) forage only with no CG (FNC), 2) forage only with management improvements to exploit CG (forage with CG; FWC), 3) forage with concentrate supplementation during two winter feeding periods (forage with supplementation; FWS), and 4) forage with supplementation during the first winter followed by feedlot finishing (forage with feedlot; FWF). The systems purchased spring-born Angus calves at 8 months of age and 180 kg live weight (LW) and finished with a slaughter weight of 550 kg. FWS system was used as reference with the performance parameters obtained during 5 years of systems experimentation. FNC used the performance parameters of FWS but during winter periods, LW gain was lower due to the absence of concentrate supplementation. FWC used the previous FNC performance parameters, but increased LW gain after the first and second winter restriction period due to improved grazing management practices thereby exploiting CG. FWF is based on the FWS system but instead of moderate supplementation during the second winter (concentrate: 3.0 kg/d/head), steers are feedlot finished (concentrate: 9.5 kg/d/head) exploiting CG due to previous summer-autumn restriction period. FNC and FWC increased age at slaughter, reducing net beef production by 21 and 11 % relative to FWS, respectively. In contrast, FWF reduced age at slaughter, increasing beef production by 93 % compared to FWS. FWS and FNC had similar profitability expressed in net margin; however, FWC and FWF increased net margin by 33 and 107 % compared to the FWS, respectively. FNC and FWC increased greenhouse gas (GHG) emissions intensity per beef produced by 17 and 3 % relative to FWS, respectively; meanwhile, FWF reduced GHG intensity by 10 % relative to FWS. Due to the inclusion of concentrates in the diet for FWS and FWF systems, the only net producers of human edible energy and protein were the forage-only systems (FNC and FWC). In summary, strategically harnessing CG in both pasture and feedlot finishing stages within a weanling-to-beef system in Uruguay successfully increased profitability. Feedlot finishing reduced GHG emissions per beef produced. However, the forage-only farm systems emerged as the only net producers of human-edible energy and protein.

Dynamics of catches and state of stocks the common dace Leuciscus leuciscus in the Middle Ob basin (in the Tomsk region)

Common dace Leuciscus leuciscus is a medium-sized representative of the Cyprinidae. It distributed in temperate latitudes of Eurasia and inhabits mainly of rivers. In the Tomsk region, it is numerous both in the Ob itself and in its tributaries. Previously, common dace was a significant fishery object — during the Great Patriotic War, its production volumes reached 2,514 tons per year and accounted for up to 20,1% of all fish catches in the region. Fishing of dace in the Middle Ob basin can be carried out 1. by special traps “atarma” in the spring during the migration of fish from the tributaries to the main channel of the Ob; 2. by lake seines in the summer-autumn period; 3. by constipation during the migration of fish from the main channel of the Ob to the tributaries for wintering grounds in the late autumn period. Previously, the main volume of dace was caught in the spring, by atarma fishing — the number of rivers on which atarmas were placed reached 128. In the last decade (2013–2022), the number of exhibited atarma does not exceed 10. The dace is fished mainly by small fishers with lake seines and using fixed networks, in the late summer — early autumn periods. The average catch of dace is 131,5 tons per year (4,6% of all fish production). Dace stocks are currently in a relatively stable state, the estimated biomass of the species ranges from 901,4 to 1539,8 tons, but it is significantly underutilized — the development of the recommended catch volumes averages only 67,5%. First of all, this is due to the low consumer demand of dace, which leads to a lack of interest among fishers in specialized fishing by atarma.

Особенности эксплуатации лесовозных дорог в весенне-зимний период

Seasonal roads are not capital construction objects. Unlike all-season ones, they can be of summer and winter action. During the transport development of forests, both allseason paved roads and temporary unpaved roads are required. The share of temporary roads is more than 90 % of all logging roads. One of the main problems of temporary logging roads is uneven seasonal operation, especially in summer. Seasonal roads do not have a permanent surface; more often it is natural soil, subject, except for mechanical impacts, to atmospheric ones, which is most evident in the summer-autumn period. Therefore, about 80 % of the harvested wood is exported via winter roads. The density of temporary roads depends on the general harvesting technology in a particular area, including the wood skidding distance and the angle of relative position of forest roads. Winter road construction works are carried out in summer and winter. In summer, engineering surveys are carried out, the optimal direction of the future route is determined, a clearing is cut, a roadbed is prepared, and if necessary, culverts are installed. With the onset of cold weather, the existing soil is compacted and leveled to accelerate its freezing. If the roadbed is sufficiently frozen, a snow-ice cover is formed. The article considers the influence of roadside forest plantations on the air temperature near the road surface, soil temperature, blocking solar radiation – the factors that are directly related to the overall service life of a winter road. Special attention is paid to slowing down the decrease in the winter road pavement strength in the shade of preserved trees by choosing the optimal route direction. The slowdown in the decrease in the pavement strength of the forest dirt road has been established and confirmed in areas where solar radiation is blocked by trees, i.e. in the shade. The difference in strength reduction to the minimum is 33 days. Based on the research results, it has been concluded that a comprehensive development of the logistics strategy for the organization of roundwood transportation via winter roads is necessary.

Seasonal-Spatial Distribution Variations and Predictions of Loliolus beka and Loliolus uyii in the East China Sea Region: Implications from Climate Change Scenarios.

Global climate change profoundly impacts the East China Sea ecosystem and poses a major challenge to fishery management in this region. In addition, closely related species with low catches are often not distinguished in fishery production and relevant data are commonly merged in statistics and fishing logbooks, making it challenging to accurately predict their habitat distribution range. Here, merged fisheries-independent data of the closely related squid Loliolus beka (Sasaki, 1929) and Loliolus uyii (Wakiya and Ishikawa, 1921) were used to explore the construction and prediction performance of species distribution models. Data in 2018 to 2019 from the southern Yellow and East China Seas were used to identify the seasonal-spatial distribution characteristics of both species, revealing a boundary line at 29.00° N for L. uyii during the autumn, with the highest average individual weight occurring during the summer, with both larvae and juveniles occurring during the autumn. Thus, the life history of L. uyii can be divided into winter-spring nursery and summer-autumn spawning periods. L. beka showed a preference for inshore areas (15-60 m) during the summer and offshore areas (32.00-78.00 m) during the winter. High-value areas of both species included inshore areas of the southern Yellow and mid-East China Seas during the autumn, enlarging during the spring to include central areas of the survey region, before significantly decreasing during the summer. Therefore, this study provides both a novel perspective for modeling biological habitat distribution with limited data and a scientific basis for the adjustment of fishery resource management and conservation measures in the context of climate change.

Impacts of seasonal activities and traffic conditions on the contamination and accumulation of gully pot sediments: Metal(loid)s and organic substances

Gully pots (GPs) are an integral urban drainage component, transferring surface runoff into piped systems and reducing sediment and contaminant load on downstream sewers and receiving waters. Sediment build-up in GPs impairs their hydraulic performance, necessitating maintenance for hydraulic function recovery. The variations in sediment accumulation rates between GPs suggested by earlier studies challenge the effectiveness of adopting a generalised maintenance frequency. This study addresses the knowledge gap regarding how various factors influence sediment contamination in GPs. The impacts of seasonal activities and traffic conditions on the contamination of sediments in 27 GPs in areas with varying traffic intensities and street features (roundabouts, intersections, and straight roads) were examined. Over one year, GPs were emptied twice, with sediments collected for winter-spring and summer-autumn accumulation periods. These sediments were analysed for 84 substances, including metal(loid)s, hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), alkylphenols, phthalates, per- and polyfluoroalkyl substances and organotins. Significant temporal changes were identified in key parameters such as electrical conductivity, total organic carbons, tungsten (W), heavy-molecular-weight PAHs (PAH-H) and diisodecyl phthalate (DIDP) in GP sediments, influenced by winter road safety measures and autumn leaf abscissions. Significantly higher concentrations of 4-tert-octylphenol, DIDP, diisononyl phthalate, antimony and W were identified in GP sediments from roundabouts compared to those at the other two street features, exclusively during the winter-spring period. This is attributed to the synergistic effect of winter road safety measures and stop-and-go traffic patterns at roundabouts. No consistent spatial and temporal patterns were identified for substance concentration and mass accumulation rates. Results underscore the potential to develop a prioritisation-based maintenance strategy as an opportunity to enhance the efficiency of GP maintenance operations, ensuring better resource allocation and reduced environmental impact.

ТЕНДЕНЦИИ МНОГОЛЕТНИХ ИЗМЕНЕНИЙ СТОКА ОСНОВНЫХ РЕК, ФОРМИРУЮЩИХСЯ В ЖАЙЫК-КАСПИЙСКОМ ВОДОХОЗЯЙСТВЕННОМ БАССЕЙНЕ

Studies were conducted aimed at the trends in the flow of the main rivers of the Zhaiyk-Caspian water basin. The average annual dynamics of river flow for a long period, their 5-year moving averages, joint tables of air temperature and precipitation values with river flow, as well as long-term dynamics of characteristic (highest, winter and lowest in open channel conditions) water flows were considered. According to the results of the research, two periods were distinguished: from 1940 to 1973 (conditionally natural) and from 1974 to 2020. (modern). In both periods, there is a tendency to reduce runoff against the background of an increase in air temperature, precipitation trends are multidirectional. Since the 1970s, there has been a decrease in the amplitude of fluctuations in annual runoff, since the 2000s there has been a decrease in both the amplitude of fluctuations and the values of maximum water flow. In the values of the lowest summer-autumn and winter water flow, on the contrary, there is a tendency to increase, which began in the late 1980s – early 1990s. For small rivers and temporary watercourses, the summer-autumn and winter periods are periods of maximum runoff depletion, during which drying and freezing phenomena (zero runoff) are characteristic.

Water Dynamics and Morphometric Parameters of Lake Sevan (Armenia) in the Summer–Autumn Period according to Satellite Data

Here, we explore the dynamics of the waters of eutrophicated Lake Sevan in the modern period, using MSI Sentinel-2 satellite images of different months in different years (2017–2022) and SAR Sentinel-1 images of similar dates. The main objective of the study is to investigate the spatiotemporal variability of the horizontal circulation of this lake and to establish whether the scheme of cyclonic water circulation in the deep-water part of Large Sevan, given in a number of publications, which does not imply water exchange between its littoral and deep-water zones, corresponds to the real picture of currents in the surface layer of the lake in the summer–autumn period (period of pronounced water stratification and intense phytoplankton bloom). The analysis performed convincingly showed that there is no constant cyclonic gyre on the scale of the deep-water part of Large Sevan (≈20 km) during the period under consideration. In most cases, non-stationary eddy dynamics are observed in Large Sevan, including mesoscale and submesoscale eddies, eddy dipoles (mushroom-shaped flows), and their packings. Often the entire deep-water part of Large Sevan is occupied by a two-cell (dipole) or even three-cell (cyclonic eddy with two anticyclones of similar size) water circulation. The time scale of the observed variability is several days. Such variable water circulation in different months (i.e., with different density stratification of water) of different years in a basin with a fairly homogeneous bottom and a slight indentation of the shoreline raises the assumption that the main reason for the non-stationary dynamics in Large Sevan is the variability of the wind effect on its surface layer. The cyclonic gyre in Small Sevan (8–9 km) is a permanent element of the circulation and maintains its position north of the strait between Small and Large Sevan. This gyre and attached anticyclonic eddies in the southern part of its periphery, as well as cyclonic submesoscale eddies in the northern part of Large Sevan, close to the strait, affect the water exchange between Small and Large Sevan in both directions. An additional objective of the study is a validation of the morphometric parameters of Lake Sevan (level, surface area, and water volume), contained in the near-real time HYDROWEB database, LEGOS, France (June 1995–January 2024), based on their comparison with the corresponding values of these parameters from gauging stations in Armenia. It is shown that, with a qualitative correspondence of the nature of lake level changes according to altimetric and instrumental measurements, its values in the HYDROWEB database exceed the data of gauging stations in most cases by 1–1.5 m in 1995–2012 and 0.5–0.6 m in 2013–2022, while the corresponding surface area and volume values according to HYDROWEB data turn out to be underestimated.

Features of the distribution and habitat conditions of cetaceans in the Barents Sea in the summer-autumn period 2004–2021

The aim of the paper is to identify the features of distribution of cetaceans in ice-free areas of the Barents Sea and adjacent waters in August-November and to characterize their habitat conditions (abiotic factors, distribution relative to mass fish species and macroplankton).The material of the study was the data collected by the Polar branch of VNIRO during the joint RussianNorwegian ecosystem surveys.Methods: geoprocessing and mapping of the studied parameters, comparative and statistical (principal component and correlation) analysis of the data.Results: Cetaceans were mainly observed in the western Barents Sea and distributed in waters with depths of from 23 to 2294 m, at temperatures of –1.9…10.7 °C and salinities of 33.0–35.2, the weighted averages of these parameters were 265 m, 3.1 °C and 34.7 respectively. Minke whales, fin whales, humpback whales, whitebeaked dolphins, killer whales, and porpoises were observed in waters with wide ranges of temperature and salinity, while blue whales and sperm whales were observed in waters with narrow ranges of these parameters. The lowest weighted average water temperature (0.3 °C) and salinity (34.4) were typical of humpback whale. Minke whale, fin whale, humpback whale and white-beaked dolphin had the largest overlap in their distribution with that of possible preys. Statistical analysis showed that priority preys for these cetaceans could be capelin and polar cod for the studied period. In addition, one of the possible preys for baleen whales was also macroplankton, and for the white-beaked dolphin — cod, blue whiting and redfishes.Practical significance: The results of this study can be used in studying the ecology of cetaceans in the Barents Sea, in assessing their impact on stocks of commercial fish species, as well as in ecosystem modeling.

Perennial grass and herb options to extend summer–autumn forage in a drought‐prone temperate environment

AbstractBackgroundThe ability to finish livestock on pasture over the summer–autumn period could improve the profitability of red meat enterprises in drought‐prone temperate regions. In south‐eastern Australia, traditional perennial options are limited by poor warm‐season performance (phalaris, Phalaris aquatica L.) and widespread environmental constraints (lucerne, Medicago sativa L.). We aimed to identify perennial species suitable for summer–autumn finishing.MethodsWe tested pure swards of summer‐active perennial grasses and herbs (20 cultivars across 14 species) in replicated small‐plot experiments at two sites on the Southern Tablelands of New South Wales, Australia. We assessed early persistence, productivity and warm‐season nutritive characteristics over 2–3 years.ResultsLucerne and chicory (Cichorium intybus L.) persisted well through drought and produced herbage of high quantity and quality through summer–autumn. Digit grass (Digitaria eriantha Steud.) was highly persistent and productive but nutritive values were generally poor. Cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), perennial ryegrass (Lolium perenne L.), prairie grass (Bromus willdenowii Kunth.) and plantain (Plantago lanceolata L.) were productive but less persistent through drought, while nutritive values were sometimes inadequate.ConclusionsChicory is a good alternative to lucerne, given its excellent summer–autumn performance, ability to survive droughts and superior acid soil tolerance. If appropriate management resolves issues with persistence and nutritive value, several of the other species could also be used to close the warm‐season feed gap in drought‐prone temperate environments.

Вплив нематоди Eustrongylides excisus (Jägerskiöld, 1990) на організм бичка-пісочника (Neogobius fluviatilis Pallas, 1814), виловленого у нижній частині Дніпровського (Запорізького) водосховища

Purpose. To determine the specifics of the influence of the parasitic nematode Eustrongylides excisus on the physiological and biochemical parameters of monkey goby (Neogobius fluviatilis) in the conditions of the lower reach of the Dnipro reservoir. Methodology. The work presents results of studies conducted in the lower part of the Dnipro Reservoir the 2020-2023 - in the village of Voyskove and village Mykilske-on-Dnieper, Dnipropetrovsk region in the summer-autumn period. Parasitological study was carried out using 780 monkey gobies. Fish were immobilized by destroying the medulla with a dissecting needle. The parasitological study was carried out by a complete anatomical dissection of the fish according to the method of K. I. Skryabin. Morphological characteristics of parasites were determined according to the guides of Bauer (1987) and Gibson (2008). Blood sampling for the preparation of smears was carried out at the place of catch. Blood was collected from the caudal artery by cautodomy. Blood smears were examined by light microscopy using a SIGETA MB-115 SE microscope at a 40x magnification. Morphometric study of erythrocytes was carried out with the help of computer analysis of microphotographs, which were made using a digital camera “Sciencelab T500 5.17 M” connected to a SIGETA MB-115 SE microscope. A Mindray biochemical analyzer was used to determine the content of total protein, albumins, globulins and glucose in fish blood. Findings. The study did not show significant differences in the hematological parameters of infected and healthy specimens of monkey gobies, however, deformation and undulation of the plasmatic membrane of erythrocytes were detected. Histological specimens showed structural abnormalities in muscle tissue and intestines. Biochemical analysis of blood showed a slight decrease in the total content of globulins and glucose in infested fish. Originality. For the first time, a comparative morphological and cytometric analysis of blood as well as histological and biochemical analysis in the case of nematode infestation of monkey goby (Neogobius fluviatilis) under the conditions of the Dnipro reservoir has been presented. Practical value. The obtained results are important for the development of measures to limit and prevent the development of parasitic diseases among the ichthyofauna of the Dnipro Reservoir and can also be used in the practical activities of fish farms. Keywords: monkey goby, nematode, invasion, tissues, erythrocytes.

Behavioural patterns of boars by breed depending on age, season, and type of ventilation

An important tool for improving the productive characteristics of pigs, including boars, is a thorough study of their behavioural patterns and reactions to compliance with housing conditions, which serves as an indicator of the protocol for assessing the welfare of this sex group in commercial pig farms. The purpose of the experiment was to identify the influence of age, season of the year, and type of ventilation on the duration of behavioural acts of boars by breeds to establish their behavioural patterns in industrial technology. The experiment involved 18 boars of the Large White, Landrace, and Duroc breeds. The boars selected for the experiments were clinically healthy and divided into two groups of 9 animals each. The control group of boars was kept in a room with a transverse ventilation system, and the animals of the experimental group were kept in geothermal air supply conditions for a year. In the process of visualising the behaviour parameters of boars of different breeds, it was found that: the duration of rest was significant (P < 0.001) affected by 49.1-67.6% – age, 10.9-23.2% – season of the year, 0.1-3.0% – type of ventilation; the duration of movement during the day was significant (P < 0.001) affected by 44.7-68.0% – age, 9.1-28.5% – season of the year, 0.5-3.2% – type of ventilation; the duration of admission feed and water were significant affected (P< 0.001) by 49.7-71.9% – age, 7.9-25.9% – season of the year, 0.1-2.4% – type of ventilation. A behavioural act that prevailed in duration and frequency (P < 0.001), especially in the summer-autumn period, was rest, which increased in time with age from 72.3% to 76.4%, regardless of the breed, season of the year, and type of ventilation. In summer and autumn, the transverse air supply system visualised abnormal apathetic behaviour during rest in animals (lying on their sides, stomach, eyes closed, without any reactions to indifferent stimuli, and the time that boars spent on stereotypical behaviour (head banging, jumping and licking the bars of the cage) increased by 3% (P< 0.95) and in the “position of sitting dog” by 2% (P< 0.95). The results obtained allow introducing the use of ethological factors in industrial pig production to increase boar sperm production, and identify individuals with behavioural deviations to develop ways to assess welfare and integrate them into production

Tracking Photovoltaics Systems at Mountain Heights

The expansion of the use of solar energy in most cases depends on the energy capabilities of each specific country. In Tajikistan, where 93% of the territory is mountains, it is necessary to build solar power plants high in the mountains. At mountain heights, the performance of panels increases in winter, in addition, the snow cover that reflects the sun's rays also contributes to an increase in the efficiency of solar panels. Experts note that solar panels receive less radiation in valleys, as clouds and fogs often prevent the passage of sunlight. At the heights of the mountains, there is no air pollution and, as a result, a longer operating time of the solar power plant. In the conditions of Tajikistan, one more drawback of solar stations in the valleys should be added - this is the rapid pollution of the panels due to dust storms in the summer-autumn period. The Chinese company Sun Tech Power Holdings will build a 10 MW power plant in Tibet at an altitude of 4000 meters above sea level.

A carbonate system time series in the Eastern Mediterranean Sea. Two years of high-frequency in-situ observations and remote sensing

The rate of ocean uptake of anthropogenic CO2 has declined over the past decade, so a critical question for science and policy is whether the ocean will continue to act as a sink. Large areas of the ocean remain without observations for carbonate system variables, and oceanic CO2 observations have declined since 2017. The Mediterranean Sea is one such an area, especially its eastern part, where there is a paucity of carbonate system data, with large areas not sampled or only sampled by ship-based discrete measurements as opposed to high frequency, sensor-equipped time-series fixed stations. The aim of this study was to analyze a multi-year time-series of high-frequency (hourly) partial pressure CO2 (pCO2) and pH measurements in the Eastern Mediterranean, along with low-frequency (monthly) measurements of total dissolved inorganic carbon and total alkalinity. The pCO2 time-series was the first obtained in the Eastern Mediterranean. The study was conducted at a fixed platform of the POSEIDON system (Heraklion Coastal Buoy) located near Crete Island. Temperature was the dominant factor controlling the temporal variability of pCO2 and pH, while the remaining non-thermal variability appeared to be related to evaporation, water mixing, and biological remineralization-production. The air-sea CO2 fluxes indicated a transition from a winter-spring sink period to a summer-autumn source period. The annual air-sea CO2 flux was too low (-0.16 ± 0.02 mol m-2 yr-1) and variable to conclusively characterize the area as a net source or sink of CO2, highlighting the need for additional high frequency observation sites. Algorithms were developed using temperature, chlorophyll and salinity data to estimate pCO2 and total alkalinity, in an effort to provide tools for estimates in poorly observed areas/periods from remotely sensed products. The applicability of the algorithms was tested using Surface Ocean CO2 Atlas (SOCAT) data from the Eastern Mediterranean Sea (1999 to 2020) which showed that the algorithm pCO2 estimates were generally within ±20 μatm of the pCO2 values reported by SOCAT. Finally, the integration and analysis of the data provided directions on how to optimize the observing strategy, by readapting sensor location and using estimation algorithms with remote sensing data.

Correlation of Lake Tyungyulyu Water Level with Larch Radial Growth in Central Yakutia

This study analyzes the monthly and seasonal correlation between the water level in Lake Tyungyulyu and the radial growth of larch across three sites in the Churapcha region of Central Yakutia. The highest Pearson correlation coefficients (r), reaching up to 0.44, have been identified between the water level and the width of the annual rings of larch (Larix cajanderi Mayr) at the third site during the summer-autumn period. These findings suggest the potential of larch in Central Yakutia as an indicator of ecological responses to hydrological conditions and climate changes.

The current chemical composition of inland water bodies of the Volga-Akhtuba floodplain (Russia)

The problem of clean water is one of the most important environmental problems in the world. It is impossible to prevent the occurrence of adverse environmental situations without careful monitoring of the aquatic ecosystems state. The assessment of the current chemical composition of the Volga-Akhtuba floodplain shallow channels (Peschanyj, Dudak, and Dudachenok) in the water-bottom sediments system was carried out. Studied shallow channels dried out during the summer-autumn lowwater period for the last few decades. Studies were carried out after the clearance and ecological rehabilitation of the shallow channels. It was found that almost all the studied indicators in water samples correspond to the established quality standards. There is uneven distribution of heavy metals in the studied shallow channels. It can be caused by the influence of hydrodynamic conditions, changes in water and sediment flow, as well as local factors, including the catchment heterogeneous geology. The analysis of the metals content in bottom sediments with permissible ones made it possible to detect excess for Hg (0.18?0.75 mg/kg), Cd (1?2.12 mg/kg), Mn (370.8?493.3 mg/kg), Ni (2.6?67.9 mg/kg), Pb (14.3?22 mg/kg), Zn (75.2?147 mg/kg). The content of As (1?1.4 mg/kg) and Cu (8.54?28.7 mg/kg) in bottom sediments does not exceed the permissible concentrations. The obtained results will form the basis for a general comprehensive assessment of the clearance and ecological rehabilitation of the Volga-Akhtuba floodplain watercourses. It is necessary to continue monitoring the watercourses state and strengthen efforts to preserve the resilient ecosystem of the Volga-Akhtuba floodplain.

European whitefish Coregonus lavaretus of the Nizhnetulomskoye Reservoir (Tuloma River basin, Murmansk region) and its habitat conditions

The modern biological characteristics of the most common polymorphic species of European whitefish Coregonus lavaretus (L.) in Northern Europe were studied in the conditions of its habitat in the oldest riverbed reservoir in the Murmansk region. A number of features of the functioning of the ecosystem of the Nizhnetulomskoye Reservoir (hereinafter NTR) have been identified, including eutrophication of the reservoir, accompanied by the development of cyanoprokaryotes in phytoplankton communities, including potentially toxic species. The introduction of the Onega smelt Osmerus eperlanus (L.) into the Tuloma River system half a century ago led to the transformation of the structure of the NTR fish community from whitefish-salmon to whitefish-smelt. Whitefish (hereinafter, this species name is only used in regard to the European whitefish) in the NTR are represented by a polymorphic population and, according to length-weight characteristics, belong to the group of medium-sized whitefish of the Murmansk region watercourses with early maturation. Based on the type of feeding, it can be classified as a benthophage with a wide range of consumption of food organisms. The stomach contents of whitefish in the summer-autumn period correlate well with the seasonality of the development of aquatic invertebrates. Artificial feeds used by the farms of rainbow trout Oncorhynchus mykiss (Walbaum) in the reservoir are currently of great importance in the feeding of the NTR whitefish. Understanding the mechanisms of structural and functional differentiation of whitefish populations is both of fundamental importance in revealing the mechanisms and direction of microevolution and adaptation of fish in changing environmental conditions and of fundamental practical importance in the implementation of protection and rational fishing, their artificial reproduction.

Dynamics of the state of zooplankton groups in aquatic ecosystems of the Buchansky district in the summer-autumn period of 2023

Dynamics of the state of zooplankton groups in aquatic ecosystems of the Buchansky district in the summer-autumn period of 2023