Variations In Water Temperature Research Articles

Advancing Aquaculture Integrating Microbiome Modulation, Immunomodulatory Approaches, and Mitigating Environmental Stressors in Nile Tilapia Farming

Sustainable aquaculture methods must be advanced to meet the problems presented by environmental stresses and the expanding worldwide need for food. This study examines cutting-edge methods for raising Nile tilapia (Oreochromis niloticus), emphasizing immunomodulatory techniques, microbiome modification, and the crucial task of reducing environmental stresses to increase resilience and production. Probiotics, prebiotics, and synbiotics are important in enhancing nutrition absorption, promoting disease resistance, and optimizing gut health, making microbiome modification an essential strategy. The use of functional feeds enhanced with bioactive chemicals and the creation of tailored vaccinations are two examples of advances in immunomodulatory approaches that have demonstrated promise in bolstering tilapia's immune systems against pathogenic threats. A holistic strategy to guarantee sustainable production is provided by simultaneously reducing environmental stresses, such as hypoxia, variable water temperatures, and pollutant exposure, through enhanced aquaculture systems, water quality control, and stress-resilient fish strains. The importance of addressing these environmental stressors is underscored, as they pose significant threats to the industry. Emerging technologies like genomics, transcriptomics, and precision aquaculture tools, which allow for the monitoring and adjusting of farming operations to suit the unique requirements of Nile tilapia, further facilitate the integration of these tactics. This review highlights the potential of comprehensive, science-driven methods in converting Nile tilapia farming into a resilient, sustainable, and fruitful enterprise and emphasizes the importance of addressing environmental stressors in this transformation.

State of knowledge for thermohaline conditions on the shelf of West Kamchatka

All available data on water temperature and salinity for the shelf of West Kamchatka are analyzed and all scientific publications and the most important unpublished thesises concerning this area are summarized. Current ideas about the water masses distribution and seasonal and long-term variability of water temperature and salinity on the shelf are discussed. There is noted that the existing estimates of seasonal and long-term variability of water temperature require significant additions for recent times (last 20 years) and certain spatial areas. Insufficient understanding is revealed for spatial-temporal dynamics of salinity in the mixing zone between the river and sea waters that requires special research.

Three-dimensional structure of interannual-to-decadal variations in water temperature in the Yellow sea during 1998‒2021

Three-dimensional structure of interannual-to-decadal variations in water temperature in the Yellow sea during 1998‒2021

Exploring Trends and Variability of Water Quality over Lake Titicaca Using Global Remote Sensing Products

Understanding the current water quality dynamics is necessary to ensure that ecological and sociocultural services are provided to the population and the natural environment. Water quality monitoring of lakes is usually performed with in situ measurements; however, these are costly, time consuming, laborious, and can have limited spatial coverage. Nowadays, remote sensing offers an alternative source of data to be used in water quality monitoring; by applying appropriate algorithms to satellite imagery, it is possible to retrieve water quality parameters. The use of global remote sensing water quality products increased in the last decade, and there are a multitude of products available from various databases. However, in Latin America, studies on the inter-comparison of the applicability of these products for water quality monitoring is rather scarce. Therefore, in this study, global remote sensing products estimating various water quality parameters were explored on Lake Titicaca and compared with each other and sources of data. Two products, the Copernicus Global Land Service (CGLS) and the European Space Agency Lakes Climate Change Initiative (ESA-CCI), were evaluated through a comparison with in situ measurements and with each other for analysis of the spatiotemporal variability of lake surface water temperature (LSWT), turbidity, and chlorophyll-a. The results of this study showed that the two products had limited accuracy when compared to in situ data; however, remarkable performance was observed in terms of exhibiting spatiotemporal variability of the WQ parameters. The ESA-CCI LSWT product performed better than the CGLS product in estimating LSWT, while the two products were on par with each other in terms of demonstrating the spatiotemporal patterns of the WQ parameters. Overall, these two global remote sensing water quality products can be used to monitor Lake Titicaca, currently with limited accuracy, but they can be improved with precise pixel identification, accurate optical water type definition, and better algorithms for atmospheric correction and retrieval. This highlights the need for the improvement of global WQ products to fit local conditions and make the products more useful for decision-making at the appropriate scale.

Simulation and Prediction of Thermokarst Lake Surface Temperature Changes on the Qinghai–Tibet Plateau

Thermokarst lakes are shallow bodies of freshwater that develop in permafrost regions, and they are an essential focus of international permafrost research. However, research regarding the mechanisms driving temperature fluctuations in thermokarst lakes and the factors that influence these changes is limited. We aimed to analyze seasonal variations in the surface water temperature, clarify historical trends in the phenological characteristics of lake ice, and predict future temperature changes in surface water of the thermokarst lakes using the air2water model. The results indicated that in comparison with air temperature, the thermokarst lake’s surface water temperature showed a certain lag and significantly higher values in the warm season. The warming rate of the thermokarst lake’s average surface water temperature based on historical data from 1957 to 2022 was 0.21 °C per decade, with a notably higher rate in August (0.42 °C per decade) than in other months. Furthermore, the ice-covered period steadily decreased by 2.12 d per decade. Based on the Coupled Model Intercomparison Project 6 projections, by 2100, the surface water temperatures of thermokarst lakes during the warm season are projected to increase by 0.38, 0.46, and 2.82 °C (under scenarios SSP126, SSP245, and SSP585), respectively. Compared with typical tectonic lakes on the Qinghai–Tibet Plateau, thermokarst lakes have higher average surface water temperatures during ice-free periods, and they exhibit a higher warming rate (0.21 °C per decade). These results elucidate the response mechanisms of thermokarst lakes’ surface water temperature and the phenological characteristics of lake ice in response to climate change.

Properties of Biofilm Prokaryotic and Eukaryotic Communities in a Representative Hypereutrophic Urban River

ABSTRACT Biofilms play an important role in nutrient and food web dynamics of shallow aquatic ecosystems. Multiple prokaryotic and eukaryotic microorganisms within biofilms interact with each other to shape the community structure and their functional attributes. However, there is no clear understanding of varied patterns of biofilm prokaryotic versus eukaryotic microbial abundances, diversities and communities, which limit our understanding of how biofilm communities and functions in hypereutrophic urban river ecosystems are changing. To elucidate the properties of biofilm communities and controls on biofilm communities in a hypereutrophic urban river, we conducted a one‐year study to investigate the seasonal and water‐depth variations on the abundance/biomass, diversity and structure of biofilm prokaryotic and eukaryotic communities. The structure and dynamics of biofilm prokaryotic and eukaryotic communities were determined by high‐throughput sequencing based on the 16S and 18S rRNA gene. Sequencing revealed that Proteobacteria, Bacteroidota and Cyanobacteria were the three dominant phyla in biofilm prokaryotic communities, and Rotifera, Chlorophyta, Annelida and Bacillariophyta were the four dominant phyla in biofilm eukaryotic communities. Biofilm bacterial abundance depended mainly on the water temperature, whereas biofilm algal biomass correlated with rotifer grazing and light levels. Prokaryotic communities had higher species richness and diversity than eukaryotic communities. Species richness and diversity displayed significant seasonal variations with minima for prokaryotic communities in winter and eukaryotic communities in summer, which were linked to water temperature and rotifer grazing, respectively. Variations in biofilm prokaryotic and eukaryotic community composition were mainly related to ammonia concentration and water temperature, respectively. The co‐occurrence network analysis suggested that rotifer grazing could considerably decrease the complexity of the biofilm network in summer, and the algal groups, especially for Chlorophyta and Bacillariophyta, were the key to the formation of stable biofilm networks. There were significant differences in seasonal and water‐depth heterogeneity of biofilm prokaryotic and eukaryotic community composition. Our findings indicate that variations in water temperature, light level, rotifer grazing and nutrients (especially ammonia) appreciably contribute to changes in the abundance, diversity and composition of biofilm prokaryotic versus eukaryotic communities in the hypereutrophic urban river. These findings increase our understanding of biofilm community characteristics in hypereutrophic urban rivers and provide insights for water pollution remediation strategies.

Diel temperature patterns unveiled: High-frequency monitoring and deep learning in lake Kasumigaura

The diel variation of water temperatures is crucial information for lakes. This study investigated such variation in Lake Kasumigaura, the second largest lake in Japan, situated 60 km from the Tokyo metropolitan area, utilizing high-frequency monitoring and deep learning techniques. Data from high-frequency monitoring of vertical water temperatures at seven depths were employed. A convolutional neural network (CNN) based deep learning model was developed and assessed across three input scenarios. The impact of forecast horizons ranging from one to 48 h ahead on model performance was examined. Results indicate a degradation in model performance with increasing forecast horizons, irrespective of input scenario or water depth. Notably, the CNN model demonstrates superior performance in near-term and medium-term forecasts compared to long-term predictions, underscoring the need for enhanced efforts in long-term forecasting. Overall, the CNN model effectively reproduces vertical water temperature profiles and captures diel variations in lake water temperatures. Incorporating additional input variables does not necessarily improve model performance; however, using surface water temperatures and air temperatures as inputs produces acceptable results for modeling vertical temperature profiles. These findings have implications for lake management in Lake Kasumigaura (e.g., controlling phytoplankton and zooplankton communities) and offer insights into water temperature modeling for other lakes.

Haematological deterioration of Hematodinium-infected decapod crustaceans.

Parasitic dinoflagellates, namely Hematodinium spp., infect a growing number of decapod crustacean species worldwide. These parasites represent a longstanding concern for fisheries in Europe and North America, and an emerging concern for aqua/polyculture systems in Asia. Known as bitter/pink/milky crab disease or post-moult syndrome, Hematodinium spp. infection can be fatal, yet there are no treatments or disease management strategies. We interrogated the available literature to enhance knowledge of Hematodinium-crustacean pathosystems, specifically haemolymph condition during parasitaemia. In this context, we sought to determine if there were invariant biomarkers (biochemical, cellular) in the haemolymph. Using meta-analytic approaches, we scrutinised published data and gathered 191 effect sizes from 17 original studies (out of >1,790) that met strict inclusion criteria covering established haematological properties like phenoloxidase activity, and ran a series of generalised linear mixed models. Additional models were constructed to consider the putative links between environmental variables (water temperature, salinity), host traits (sex, size), and parasite burden. Overall, depleted haemocyte numbers (e.g., hyaline cells) and protein levels (e.g., haemocyanin) coincided with patent Hematodinium presence in crabs and langoustine. Crustaceans were more likely to have severe burdens of Hematodinium when external salinity levels exceeded 30 psu, and potentially immune-compromised >20oC. Hematodinium-driven hypoproteinemia and haemocytopenia were more pronounced in wild-caught animals than those infected in laboratory trials, thereby emphasising the need to secure data in natural settings. This is the first meta-analytic study to present clear evidence in support of broad haematological deterioration in crustaceans parasitised by Hematodinium spp., and environmental factors linked to immunopathology.

Study on water temperature variation trend and disturbance patterns in hydropower development section of the upper Yellow River

Study on water temperature variation trend and disturbance patterns in hydropower development section of the upper Yellow River

Spatial-temporal characteristics and the importance of environmental factors in relation to algal blooms in coastal seas

In the prediction of algal blooms with the artificial intelligence (AI) technology, the proper selection of the indices is crucial to the quality of the results. Although eutrophication and climate change have been identified as the main contributors to algal blooms, limited knowledge of the relationships among environmental factors hinders the accurate and correct AI prediction. To explore the importance of environmental factors in the occurrence of algal blooms in coastal seas and facilitate the selection of inputs for the prediction model, this study examines observed water quality data and analyzes their relationship using machine learning methods. It was found that nutrients, water temperature, and salinity play important roles in controlling algal blooms in coastal seas, and their influence varies depending on locations. The high-risk cases of algal bloom mainly occur in environments with medium salinity (22–28 psu), particularly in open estuaries with high nutrient levels. According to the feature importance analysis, water temperature presented the most significant impact on algal bloom risk compared to other environmental factors. The variations of water temperature and Chl-a concentration are synchronous when the water temperature is below 32 °C. Additionally, the relationships between inorganic nutrients (NO3−-NO2− and Ortho-P) and Chl-a exhibit asynchronous across multi-temporal scales. The uptake of inorganic nutrients occurs in large quantities within the 24 h prior to the boom in Chl-a concentration. This demonstrates that variations in concentration of inorganic nutrients can be considered as crucial factors in algal bloom predictions, and their significant decrease can be served as an important signal of an impending algal bloom. This study enhances our understanding of the mechanisms behind algal blooms and facilitates their management and prediction strategies in coastal seas.

Spatio-Temporal Variability of Water Temperature of Arctic Rivers in Russia over the Past 60 Years

This article presents the findings of a comprehensive statistical analysis based on one of the largest and most up-to-date datasets on average monthly water temperatures at 286 hydrological stations from 1961 to 2021. Through this analysis, a detailed examination of the factors influencing temperature formation in different landscape-diverse regions in the Russian Arctic has been conducted. It has been determined that air temperature plays a crucial role in determining water temperature, although its influence is constrained by geographical factors, primarily geographical latitude. An analysis of discontinuities in uniformity and the presence of trends was carried out, along with a regression analysis of the relationships between air and water temperatures. The results of estimating changes in river water temperature were simultaneously compared both with respect to generally accepted climatic periods (1961–1990 and 1991–2020) and with respect to revealed change point years. The results of the statistical analysis indicate a relatively slow increase in water temperature in the Arctic rivers of Russia over the past 60 years, by 0.11–0.74 K/decade. These changes are mainly due to changes in air temperature (about 70% of cases), which in turn are influenced by the altitude of the location of the objects and other local factors.

Periodic temperature modulation as a strategy to enhance barley hydration process efficiency

Barley is a very versatile raw material, widely used in several industries, mainly in the production of beverages in the form of malt. However, the conventional malting process requires more than 14 hours for the grain to reach the moisture level necessary for germination, which significantly increases production costs. In search of faster and more economical methods, this study investigated periodic temperature modulation as a strategy to optimize the barley hydration process. Using the BRS ELIS. barley variety, the study tested the periodic variation of water temperature during the hydration process. The best result was obtained with a temperature of 15 ± 7.5 ºC, which reduced the hydration time by 71% compared to the isothermal process, which uses constant temperature. The applied diffusion model accurately predicted the moisture absorption data (r² > 0.94, P < 9.54% and RMSE < 3.8%). The results show that periodic temperature modulation is an effective technique to accelerate barley hydration, offering a promising way to make the malting process more efficient and less costly for the industry.

A comprehensive study of the life history traits of Trematomus newnesi (Pisces, Notothenioidei) off the South Shetland Islands

Understanding the life history traits of Antarctic fish species is crucial for effective management and conservation purposes. This study provides a comprehensive evaluation of the reproductive dynamics, age and growth characteristics in Trematomus newnesi, a common nototheniid species in the High-Antarctic zone. Field observations conducted in Potter Cove, South Shetland Islands, revealed significant variations in photoperiod and water temperature from November to March, with water temperatures reaching a peak in mid-December. The gonadosomatic index, as a proxy of gonad development, increased exponentially in both sexes from November to March. Sex steroid plasma levels, particularly testosterone (T) and estradiol (E2), showed significant temporal variations, with a significant increase in the period when late vitellogenesis was evident, suggesting the proximity of final maturation and spawning. Age estimation through otolith readings provided a range of ages up to five years for both sexes. Comparison with previous studies on T. newnesi from other Antarctic areas highlighted similarities in reproductive patterns and differences in growth parameters. Photoperiod and an increase in temperature resulted to be trigger factors promoting vitellogenesis in T. newnesi, ending in an early austral autumn spawning event. The environmental cues and reproductive data recorded at Potter Cove suggest that this area serves as a spawning ground for T. newnesi. Likewise, larval hatching was estimated to occur from early to mid-August, after an egg incubation period of four months. Overall, this study provides insights into the life history traits of T. newnesi, as a valuable contribution for appropriate management and conservation of Antarctic fish populations.

Variability in Water Temperature Vertical Distribution and Advective Influences: Observations from Early Summer 2021 in the Central Yellow Sea

To analyze variations in the vertical distribution of water temperatures and the impact of advection in the central Yellow Sea, multi-layer water temperature and current observations were conducted from 31 May to 8 June 2021. Water temperatures exhibited a typical three-layer summer structure, with a uniform deep-layer temperature averaging 8.23 ± 0.05 °C. The current field was dominated by northeast–southwest tidal currents, but residual current characteristics indicated that non-tidal components significantly influenced circulation. Water temperature changes lagged tidal changes by about 3 h, with strong correlations (R > 0.7), especially in deep layers. Residual currents showed significant correlations with water temperature variations, which were attributed to advective displacement or baroclinic currents. Empirical orthogonal function (EOF) and complex EOF analyses revealed that thermocline variations (T1, explaining approximately 75% of total variance) were driven by strong northward (C1, approximately 34%) and cyclonic (C2, approximately 32%) advection. In deep layers, slight temperature changes were caused by southward Yellow Sea Cold Water Mass (C1) and northward Yellow Sea Warm Current Water (C2) propagation. This study confirms that vertical water temperature variations result from a complex interaction between various advection patterns, with southward tide-induced residual currents (C3, approximately 12%) playing a key dynamic role.

Evaluation of critical process parameter on the production of sustainable bead foams based on polylactic acid

A commercial grade of polylactic acid (PLA) was foamed without using modifiers to obtain expanded polylactic acid bead foams (EPLA). Typically, the foaming process is influenced by both melt properties and crystallization behavior. While factors like water temperature, die structure, and die temperature are known to have effects on bead foam processing, these aspects have not been thoroughly explored in the context of PLA bead foam production. To address this gap, a comprehensive investigation was undertaken, varying water temperature, die structure, and die temperature to discern their impact on PLA processing behavior. Results revealed that water temperature significantly influenced foaming behavior, particularly at elevated temperatures near the glass transition of PLA. Additionally, the study demonstrated that die size wielded a notable influence on all foam properties, dictating process limits. With the selection of an appropriate die size, the die temperature could be manipulated within the range of 190°C to 160°C, revealing a substantial impact on the overall process. Remarkably, the lowest densities achieved were 63 kg/m3 with an average cell size of 36 µm and a cell density of 1.1*107 cells per cm3.

Analysis of Tubular NF Plants in Scotland Indicates That Summer Temperatures and Redox-Sensitive Elements Are Correlated with Membrane Biofouling and Shortened Useful Life.

We investigate the effects of seasonal variations in water composition and temperature on the performance of two full-scale drinking water treatment plants in Scotland, equipped with tubular cellulose acetate nanofiltration membranes. Multiple environmental and water quality parameters, recorded over a 4.5-year period, were correlated against membrane permeance, cleaning frequency, and useful life. Membrane autopsies enabled the characterization of the foulant composition. Temporal variations in temperature at plant X led to significant biofouling (manifested by permeance losses of 30-50%, and bacteria detected on the membrane surface) during the summer months, when water temperatures exceeded 20 °C and microbiological activity was highest. Plant Y, in contrast, displayed smaller seasonal variations and was operationally stable without significant fouling. A pronounced increase in manganese and iron (up to 200 and 600 μg/L, respectively) in the lake water at plant X in summer was accompanied by elevated content (∼60 mg/m2) of those metals on the membrane surface, which was consistent with lake thermal stratification and metal input from the sediment into the water column. Our work shows that membrane plants in regions supplied by standing surface water bodies, such as plant X, are more vulnerable to biofouling, especially during warmer months.

Genome-Wide Identification and Characterization Thaumatin-like Protein (TLP) Genes in Wild Olive (Olea europaea var. sylvestris)

The wild olive tree (Olea europaea var. sylvestris) is the ancestor of all olive varieties, displaying remarkable adaptability to diverse climatic conditions and soil types. This iconic tree of the Mediterranean Basin stands out for its ability to withstand environmental stresses, such as water scarcity and temperature variations, playing a crucial role in the ecology, economy, and culture of the region. In this study, 42 TLP genes were characterized in the wild olive tree, distributed across 14 chromosomes and nine scaffolds. In silico analysis revealed the presence of domains associated with antifungal activity in some sequences, indicating their potential role in pathogen resistance. The structural diversity of OeTLP genes was explored through multiple alignments, conserved motifs and phenetic analysis. Correlation was observed between phenetic diversity, genetic structure, and motif patterns, suggesting different functions among OeTLP groups. Additionally, the distribution of exons and introns in the pheneticc tree provided further insights into the evolution of these genes. Comparative modeling of OeTLPs unveiled three-dimensional models with good structural quality and distinctive surface charge characteristics. This study provides a comprehensive understanding of the physicochemical, structural, and phenetic features of TLP genes in Wild Olive, contributing to knowledge about this species' response to environmental stresses and pathogens.

The Impact of Climate Change on Cropping Patterns in the Jurang Sate Hulu Irrigation Area

For many years, the active management of the Jurang Sate Hulu Irrigation Area has provided significant benefits to cropping patterns. However, the impacts of climate change on water availability and temperature variations present critical challenges to crop productivity. Therefore, an analysis of the effects of climate change is essential. The methods employed in the analysis of climate change include correlation and regression methods. This study uses nine variables of global climate change. The correlation method is applied to determine the extent of the influence of global climate variables, represented by Global Circulation Model (GCM) data, on rainfall and climate in the Jurang Sate Hulu Irrigation Area. The regression method is used to validate the prediction model for rainfall from 2024 to 2100. In the cropping pattern analysis, the Penman-Monteith method is used to calculate evapotranspiration, while the F.J. Mock method is used to calculate flow discharge. Based on the analysis, the global climate variables that most significantly influence rainfall in the Jurang Sate Hulu Irrigation Area are air temperature, wind speed, eastward wind, and surface temperature, with maximum correlation values of 0.551, 0.540, 0.589, and 0.625, respectively. In contrast, local climate variables have less influence, as they yield correlation values below 0.500. The regression analysis showed an average validation result for the selected model using two goodness-of-fit parameters: Root Mean Square Error (RMSE) of 124.371 and Nash-Sutcliffe Efficiency (NSE) of 0.403. The highest irrigation water requirement occurs during the third planting period, from 2051 to 2075, at 0.465 m³/s. The planned cropping pattern is paddy-paddy-second crops, with planting areas of 3,807 hectares for the period from 2024 to 2050, 3,595 hectares for the period from 2051 to 2075, and 3,383 hectares for the period from 2076 to 2100, with a total planting intensity of 300% during each period.

Does the karst spring improve fish abiotic habitat in mountain streams?

Mountain streams constitute challenging habitat for many fish species due to rapid and variable flow, cool temperature, and limited food resources. Groundwaters recharge by karst spring may however mitigate harsh habit conditions of mountain streams providing niches for different fish species. This study aims to assess the suitability of mountain streams, replenished by karst springs, for various fish species like alpine bullhead, European grayling, brown and brook trout. The study was conducted in the Chochołowski Stream in the Western Tatra Mountains, Poland. The assessment of abiotic habitat is based on different characteristics of hydrological and thermal regimes as well as water chemical composition investigated between 01.09.2012 and 31.09.2014. The findings reveal that: 1) downstream variability of habitat abiotic conditions (such as water temperature, flow, water chemical composition) may affect the distribution of fish species, 2) karst springs contribute up to 100% of the stream’s recharge during periods of winter low flow, 3) karstic groundwater reduces the variability and amplitudes of stream water temperature and weaken the periodicity in water temperature associated with daily course of air temperature and solar radiation, 4) groundwaters prevent stream freezing in winter and moderate summer temperatures, 5) increasing mineralisation of water below the spring recharge may positively affect fish distribution. The findings underscore the importance of karst springs in modifying the abiotic conditions of fish habitat in mountain streams.

Effective and environment-friendly oil removal with microbubble jet

Effective removal of oil contaminants from solid surfaces is crucial for various applications. However, traditional cleaning methods often involve the use of hazardous chemicals. Because of their stability and ability to adsorb pollutants, microbubbles are considered as a promising alternative for environmentally friendly cleaning. This study explores the enhancement of oil cleaning efficiency using a microbubble water jet. The properties of the microbubbles generated via ultrasonic agitation are examined under varying water temperatures, ultrasonic amplitudes, and surfactant concentrations. The microbubble jet demonstrates approximately 29 % enhanced cleaning efficiency compared with a single-phase water jet. Visualization techniques, including particle image velocimetry, reveal that this enhancement is driven by the behavior of microbubbles consistently adsorbing oil through hydrophobic interactions as well as the instability and increased turbulence intensity of the microbubble jet. Additionally, the higher (by 7 %) spreading velocity of the microbubble jet indicates the free surface of bubbles results in a drag reduction. Consequently, this enables the jet to cover wider regions to be cleaned effectively. The present findings demonstrate the potential of microbubble jets as an effective and eco-friendly alternative for oil removal and offer insights for their practical implementation in diverse fields utilizing microbubbles.