Influence Of Water Temperature Research Articles

Effects of water temperature on soil aggregate stability between soils developed from different parent materials in the subtropical hilly area of China

Water temperature has an important effect on soil aggregate stability. In this study, six soils derived from different parent materials in the hilly region of southern China were selected, and the mean weight diameter (MWD), geometric mean diameter (GMD), and soil erodibility (K value) were measured under different water temperature conditions. The aim of this study was to investigate the influence of water temperature on soil aggregate stability and erodibility. As the water temperature increased from 5 °C to 40 °C, the average content of >5 mm water-stable aggregates decreased by 57.13 %, while the average content of <0.25 mm water-stable aggregates increased by 214.41 %. The MWD and GMD of the six different parent soil types exhibited a decreasing trend with increasing water temperature. The trend of the K value was opposite to that of these values. The influence of water temperature on soil aggregate stability is mainly attributed to the thermal effect on the viscosity of soil water and the expansion of clay minerals. As the water temperature increases, the water viscosity coefficient, water density and water surface tension gradually decrease. Moreover, the response of soil aggregate stability and erosion resistance to water temperature varies with soil depth and parent material type. The topsoil exhibits greater sensitivity to water temperature than does the subsoil. Shale (SH) soils and quartz sandstone (QS) soils exhibited higher sensitivities, and Quaternary red clay (QRC) soils exhibited the lowest sensitivity to water temperature among the six soils. This difference is mainly attributed to differences in the contents of expansive clay minerals and organic matter. These results indicate that soil aggregate stability and erosion resistance decrease with increasing water temperature, which may be one reason for severe soil erosion under extremely high temperature and rainfall conditions in the southern red soil hilly region during summer.

Physiological effects of interacting native and invasive bivalves under thermal stress

AbstractAcross many ecosystems in North America and Europe, native freshwater bivalves (Order Unionida) are threatened by fouling and competition for food by the invasive zebra mussel Dreissena polymorpha. In light of climate change, knowledge on the influence of water temperature on these competitive effects is important, yet poorly understood. This study examines the physiological impact of the interaction between D. polymorpha and the native European unionid Anodonta cygnea over a 28 day—period in response to water temperatures of 12, 19, and 25 °C by comparing their glycogen, glucose, lipid and protein concentrations. The laboratory experiment comprised three treatments: (1) fouling of A. cygnea by D. polymorpha, (2) both species present but not fouling; and (3) a control in which A. cygnea and D. polymorpha were placed separately. Increased water temperatures caused physiological stress in D. polymorpha as evident from reduced glycogen, glucose, lipid and protein concentrations. Dreissena polymorpha benefited from fouling of unionids, as individuals that fouled A. cygnea tended to have increased glycogen, glucose, lipid and protein concentrations. Competitive effects of D. polymorpha over the unionid bivalve species, however, were not intensified by elevated temperatures. Glochidia release, lower infestation intensity, and physiological stress of Dreissena at higher temperatures were likely confounding factors. The results of this study suggest that understanding the physiological consequences of species interactions at changing temperatures can be an important tool to assess future climate change impacts on freshwater bivalves and aquatic community structures.

Evaluation of Post-Surgical Recovery in Olive Flounder (Paralichthys olivaceus) by Assessing Behavior, Heart Rate, and Wound Healing

This study examined the post-surgery recovery of olive flounder (Paralichthys olivaceus) following tag insertion by analyzing behavior, heart rate, and wound healing. The experiments used 30 individuals (length: 38.67 ± 2.12 cm; weight: 742.48 ± 116.41 g). Heart rate was measured using a DST milli-HRT (Star-Oddi) bio-logger. To assess the influence of water temperature on the recovery process after surgical tag insertion, behavioral analyses, heart rate, and wound healing were conducted in two experimental groups: Experiment 1 (22 °C, optimal water temperature); Experiment 2 (28 °C, high water temperature); and control group (22 °C, non-operated fish). The experiment was repeated twice over a 7-day period for each experimental group. Compared to the non-operated fish, the operated fish exhibited stable levels after the 3rd to 4th day in Experiment 1. Statistical analyses based on heart rate in Experiment 1 indicated that the appropriate post-surgery recovery time point was approximately 3 days, representing the point at which behavioral fluctuations stabilized. In the case of Experiment 2, abnormal behavioral patterns (e.g., tilted swimming) and changes in average swimming time and daily heart rate were found to stabilize after 4 days post-surgery.

Spatial analysis of water quality parameters concentration around the floating solar panel installation in Lake Mahoni, Depok, Indonesia

The transition to renewable energy, specifically solar panels, is increasingly popular. There has been an innovation to place solar panels floating on water. However, floating solar panels (FSP) affect the water quality parameters below them. This study aims to analyze the concentration of water temperature, dissolved oxygen (DO), and biochemical oxygen demand (BOD) spatially in the area surrounding the FSP in Lake Mahoni, examining the influence of air temperature on water temperature as well as the influence of water temperature on DO and BOD. During three weeks of observations, samples were collected from 9 sampling points around the FSP, once a week in the morning and afternoon. Data processing and analysis were performed using descriptive statistical methods, normality tests, comparative tests, correlation tests, and spatial mapping. The highest results indicate DO, BOD, and temperature changes between the upstream area and below the FSP ranged from -1.77 to 0.48 mg/l, -2.68 to 1.78 mg/l, and -0.50 to 0.60°C, respectively. Conversely, the highest changes from below the FSP to the downstream area ranged from -1.55 to 4.54 mg/l, -1.91 to 3.34 mg/l, and -0.30 to 0.80°C, respectively. Water temperature and DO show patterns below the FSPs area, but no pattern is observed in BOD. A significant positive correlation was found between air and water temperature (ρ=0.945, p=0.005). A significant correlation was observed between water temperature and DO (ρ=0.87, p=0.002) and BOD (ρ=0.803, p=0.009) upstream of the FSP in the afternoon. In contrast, there was no significant influence on water temperature, DO, or BOD in the morning (P&gt;0.05) in the upstream area and below the FSP.

Залежність лінійного зростання та виживання личинок субтропiчної прiсноводної креветки (Мacrobrachium nipponense Dе Haan, 1849) від температури і солоності

Purpose. Studies of the growth and survival of Oriental river prawn (Macrobrachium nipponense) larvae depending on water temperature and salinity during cultivation. Methodology. Experimental studies were carried out at the Aquatic Department of Aquatic Bioresources and Aquaculture of the Odesa State Ecological University in 2020-2021. Brood Oriental river prawns (Macrobrachium nipponense) were caught in the lower Dniester river and placed into a 0.8 m3 RAS. The larvae were stocked in separate aquariums with automatically maintained specified temperature regime. The first series of experiments in fresh water investigated the influence of water temperatures of 20–22, 22–24, 24–26, and 28–31°C on the growth of shrimp larvae (from the 1st stage to the Pl stage). Cultivation in water with a salinity of 5, 7, 12 ‰ was carried out at a temperature of 20–22, 22–24, 28–31 °C. Ten prawn larvae were measured daily under a binocular microscope (MBS-10) using an eyepiece-micrometer. The stage of larval development and the survival rate were determined. Water salinity was determined using an ATAGO-100 refractometer, and an Azha-101M thermal oximeter was used to determine the oxygen content in water. Statistical processing of data was carried out in Microsoft Excel. Findings. It was established that at a temperature of 24–26°C, the duration of the transition from one stage of larval development to another in Oriental river prawn (Macrobrachium nipponense) increased as the larvae grew and developed. It lasted 4–5 days in the first stages (1-3), then stages from 6 to 9 days in the later stages. High temperature stimulated the growth of larvae and accelerated their development. In fresh water at a temperature of 29–31°C, the length of postlarvae (Pl) reached 6.69±1.15 mm in 28 days of rearing. Cultivation at high temperature resulted in a significant variation in larval sizes (from 4.4 to 8.6 mm CV–25,27). At lower temperatures (25-27, 22-24 and 20-22°C), the average sizes of prawn postlarvae were smaller (5.83±0.78, 4.56±0.15, 4.43±0.15), and the survival rates increased (46, 49 and 54%, respectively). Survival of larvae was inversely dependent on temperature r = –0.89. It was minimal (32%) at a temperature of 29–31°C. The higher the growing temperature, the lower the output of postlarvae. Water salinity, like temperature, significantly affected the growth, survival and size uniformity of postlarvae. In water with a salinity of 5‰, postlarvae reached their maximum length (6.56±0.15 mm) at a temperature of 29-31 °C. At temperatures of 20-22 and 22-24 °C, the size of the postlarvae did not reliably differ among themselves. The maximum survival of postlarvae (52%) was noted at a temperature of 22-24°. Regardless of water temperature, salinity of 5‰ ensured high uniformity of larvae size (CV: 6.11–9.09). At a salinity of 7‰, the maximum length of postlarvae was reached at a temperature of 29-31oC, and the highest survival rate of prelarvae (34%) was noted at a temperature of 20-22oC. The size of the larvae and their survival at other growing temperature conditions did not differ significantly (Р&lt;95). A salinity of 7‰ also ensured the uniformity of postlarvae sizes (CV: 6.12-8.97). At a salinity of 12‰, high water temperature stimulated the growth of larvae with relative uniformity of their linear sizes, but in all variants of the experiment the survival rate of postlarvae was very low (4–9%). Originality. Experimental data on the growth and survival of larvae of the Oriental river prawn (Macrobrachium nipponense) depending on temperature and salinity are presented for the first time. The influence of the salinity of the environment on the size uniformity of the larvae was established. Practical value. The obtained results can be used for the development and improvement of methods of artificial reproduction and cultivation of the Oriental river prawn (Macrobrachium nipponense) under controlled conditions in recirculation aquaculture systems (RAS).

Insights into Daily Dynamics of Fish Migration during Spring in the Konda River

Hydrology and temperature are known as key drivers for fish migration in floodplain-channel systems of large rivers. The Lower Irtysh contains valuable species of whitefish and sturgeon. Thus, along the Konda River, a complex study was carried out in order to investigate fish migration in spring, with a focus on daily and monthly dynamics. To estimate the number of fish passing up- and downstream, a hydroacoustic system with a scanning beam frequency of 455 kHz was deployed in May 2017. The survey revealed the presence of three peaks in migration activity, as well as differences between a location close to the shore and another in the main channel. Regression analysis revealed a high degree of reliability of the influence of water temperature on the number of migrating fish (p &lt; 0.001). The dataset also showed a daily rhythm of fish migration. An analysis of the daily variation in the illumination index and the intensity of fish migration revealed the presence of noticeable and high correlations for upstream (RS = 0.55; p &lt; 0.05) and downstream migration (RS = 0.71; p &lt; 0.001), respectively. Our data underline the importance of temperature as a trigger for fish migration and reveal diurnal patterns related to illumination.

The Influence of Water Temperature on Seawater Evaporation in the Desalination Process

The Influence of Water Temperature on Seawater Evaporation in the Desalination Process

A simplified method for the thermal performance analysis of double-layer pipe-embedded external wall

Reducing the heat dissipation through the envelope is critical for heating energy savings in buildings. Double-layer pipe-embedded external wall (DPEW) has the advantage of load interception and low-temperature heating, and is a promising solution to reducing energy demand for heating. To gain a comprehensive understanding of the thermal performance of DPEW, a thermal network model is established in this study, which characterizes the steady heat transfer process of DPEW by the superposition of water temperature, outdoor temperature and indoor temperature. The accuracy of the proposed model is validated against experiment data in the literature. Evaluation indexes including equivalent overall heat transfer coefficient (U-value), equivalent outdoor temperature, and energy utilization rate of outer pipe or/and inner pipe are proposed based on the thermal network model of DPEW. A case study is conducted under typical winter conditions of Beijing to investigate the influence of water temperature and outdoor temperature on the thermal performance of DPEW. The results show that the energy utilization rate of DPEW increases with the increasing outdoor temperature and inner pipe water temperature, and the decreasing outer pipe water temperature, while the energy utilization rates of the outer pipe and inner pipe remain largely unaffected. At the outdoor temperature of −9 °C, the outer pipe water temperature of 10 °C and the inner pipe water temperature of 25 °C, the energy utilization rates of the outer pipe, inner pipe, and DPEW reach approximately 27 %, 89 % and 65 %, respectively. This study gives an insight into the steady-state thermal performance of DPEW, and provides guidance for its further research and application.

Production of probiotic powdered barberry (Berberis vulgaris) juice by cast-tape drying technique

Edible seedless barberry (Berberis vulgaris) is an indigenous Persian fruit containing anthocyanins. Drying techniques provide more access of seasonal fruits. Cast-Tape-drying (CTD) is an innovative, safe and competitive drying technology, which employs hot water thermal energy for dehydration. A Central-composite-design was used to investigate the influence of water temperature (75- 95 °C) and Arabic gum concentration (10- 14%) to produce CT-dried powder. Increasing water temperature decreased moisture content, bulk density, total anthocyanin content (TAC) and total phenol content (TPC) and increased hygroscopicity and hausner ratio (P < 0.05). When Arabic gum concentration increased from 10 to 12%, moisture content, hygroscopicity and bulk density decreased while, hausner ratio, TAC and TPC increased (P < 0.05). Increasing both variables resulted in brighter purple color. Microstructure assay revealed dented particles with sharp edges. Glass transition temperature achieved around 63.6 °C. To promote the functionality, Bacillus coagulans IS2 and Lactobacillus plantarum A7 (109 CFU/g) were incorporated in optimized barberry powder and examined under simulated gastrointestinal condition and during storage. The CTD would be able to be used as a novel method producing powdered barberry juice. By utilizing this technique, it is possible preserve the survivability of B.coagulans, while, L.plantarum may require additional strategies to maintain the survivability during drying.

Dynamics of Decapoda larvae communities in a southwest Iberian estuary: Understanding the impact of different thermal regimes

Environmental conditions play a pivotal role in shaping the dynamics of meroplanktonic communities, which represent a vital life stage, crucial for successful recruitment. Specifically, temperature can impact the survival and duration of larval development in decapod crustacean species. The objective of this study is to analyze the community of decapod larvae in the Guadiana estuary, located in southwest Iberia. The analysis focuses on the community's taxonomic composition, temporal variability, and the influence of environmental factors. Particularly, the study emphasizes investigating the impacts of different thermal regimes on the abundance of these assemblages. A comprehensive zooplankton sampling program was conducted at a single station in the lower estuary, from 2014 to 2022. The decapod larvae assemblages are dominated by Upogebia spp., followed by Diogenes pugilator, Panopeus africanus, Afropinnotheres monodi, and Polybius henslowii species. The results of structural equation modeling unveiled a strong influence of water temperature and salinity on the community, while chlorophyll-a concentration, river runoff, and the large-scale climatic mode North Atlantic Oscillation (NAO) revealed no impact on the abundance of these assemblages. Overall, the community and the main taxa displayed a positive linear trend in response to increased salinity. However, the effect of increasing temperature varied among species. In the current climatic scenario, water temperature emerges as a critical factor in predicting seasonal variation of the assemblages' abundances, exhibiting a marked seasonality during spring and summer. Predictive models used to investigate future scenarios, Representative Concentration Pathway (RCP) 2.6 and RCP 8.5, defined by the International Panel on Climate Change (IPCC), where the temperature is expected to rise 2 °C and 4.3 °C by 2100, suggest the possibility for an alteration in assemblages' composition, where the abundances of D. pugilator, the second most abundant species, tend to decrease abruptly. Reported evidence, coupled with the typical Mediterranean climate of the region, where extreme climatic events, like marine heatwaves, are becoming more frequent, the high connectivity with the Mediterranean Sea, where invasion by non-indigenous species is increasing, also connected with changes in freshwater discharges, may trigger significant alterations in species dominance and abundance, with ecological and socio-economic implications.

The effect of climate oscillations on skipjack tuna (Katsuwonus pelamis) in the Indian Ocean

Skipjack tuna (Katsuwonus pelamis) (SKJ) is one of the most commercially important marine fish species distributed throughout the world's tropical and subtropical oceans. The Indian Ocean is a main fishing ground for SKJ, whose exploitation rate is just below the maximum sustainable yield. Therefore, SKJ stocks may potentially be significantly affected by climate change. In this study, climatic oscillation indices related to the Indian Ocean, including the Indian Ocean Dipole (IOD), the mean water temperature anomaly in the Eastern Indian Ocean (EIO) and Western Indian Ocean (WIO), the Madden-Julian Oscillation Index at 80°E (MJO80) and the Arctic Oscillation Index (AOI), were associated with SKJ catch per unit effort (CPUE). This study aimed to understand the effect of these five climatic oscillations on SKJ, with the goal of optimizing the utilization of skipjack tuna in the Indian Ocean. We combined gradient forest analysis (GFA) and generalized additive models (GAMs) to evaluate the importance of each climatic index with a 0–5 year lag on the impact of SKJ CPUE and to establish an optimal prediction model. The GFA results show that MJO80 is the most important climatic index influencing SKJ CPUE, followed by MJO80_1, AOI_2, IOD_4, WIO_2, etc. The best GAM model includes MJO80, AOI_2, and WIO_2, which could be related to the recruitment and larval survival of SKJ by influencing water temperature. Meanwhile, there is a significant negative correlation between SST and SKJ CPUE in the tropical regions of the western and central Indian Ocean. Our results suggest that climate oscillations have a 0–2 year lag effect on the SKJ fishery in the Indian Ocean, which can be used to predict resource changes in SKJ over the next 2 years.

Influence of Temperature on the Removal Efficiency of Organic Matter and Ammonia from Micro-Polluted Source Water

Temperature is an important factor influencing the treatment effect of biological aerated filters (BAFs). In this study, BAFs incorporating biological manganese oxides (BMOs) were used to treat micro-polluted source water containing organic masses and ammonia, and the influence of temperature on the removal efficiency of the pollutants was investigated. The results showed that after the formation of biogenic manganese oxides (BMOs) in the filter layer, the removal efficiency of CODMn significantly improved. When the water temperature was approximately 24 °C, 16 °C, and 6~8 °C, the removal rates of CODMn, ammonia, and manganese were 60.64, 42.55, and 20.48; 98.40, 95.58, and 85.04; and 98.70, 97.63, and 96.38%, respectively. The influence of water temperature on the removal efficiency of the pollutants was hierarchically structured as follows: CODMn &gt; ammonia &gt; manganese. Analysis of the removal efficiencies of the pollutants along the filter layer showed that CODMn had been eliminated in every filtration layer, and ammonia and manganese were mainly removed in the 0~0.4 m and 0~0.8 m regions of the filter layer, respectively. With a decreasing water temperature, the concentrations of CODMn, ammonia, and manganese along the filter layer increased. The biological CODMn, manganese, and ammonia removal processes were all first-order kinetic reactions. With a decreasing water temperature, the kinetic constant k gradually decreased, and the reaction half-life (t1/2) gradually increased.

An Enhanced Measurement for Inorganics in Water Based on a Novel Planar Three-Electrode Sensor

Although conductivity is prevalently used in water quality detection for inorganic ions, its utility could be weakened when various kinds of ions are involved as it merely embodies water bulk resistance indiscriminately. Aiming at detectability enhancement, the paper proposes a novel measurement method utilizing interfacial impedance for further exploration of ions. Based on theoretical analysis and measuring model comparison, a current-controlled method with difference measurement was derived, as well as the equivalent circuit. Then, a novel three-electrode sensor with planar structure was accordingly designed and fabricated. After measurement parameters optimizing by experiments of frequency response and amplitude response, the sensor was tested with traditional two-electrode sensor and conductivity sensor. Experimental results not only testified performance of the proposed one in interfacial impedance measurement, but also revealed a reduction process of interfacial impedance with increasing conductivity. Influence of water temperature was tested, too. Impedance differences between anion and cation inspired further experiments involving more ion species, which demonstrated that diverse positive ions trended to have similar relationships between conductivity and interfacial impedance while the relationships differed due to types of negative ions. The relationships make the measurement a promising tool for ion detection in certain applications.

An assessment of the economic feasibility of the floating PV technology in Aotearoa–New Zealand

Electricity generation from utility-scale solar facilities is projected to grow to between 5 and 16 TWh by 2050 in Aotearoa–New Zealand. The floating photovoltaic (FPV) technology is considered a viable option for the country, because of the good solar resource at existing hydropower schemes. This paper aims to inform the understanding of the economic feasibility of FPV systems through the analysis of specific cases – Maraetai Dam and Lake Tekapo. To do so, the solar resource and FPV outputs are obtained through the modelling of Solargis and using industry standard technical specification. As well as the normal uncertainties associated with (potential) FPV performance evaluations, the influence of water temperature is also considered. The overall FPV output is estimated to be between 1,115 and 1,497 kWh/kWp. Using available Engineering, Procurement and Construction (EPC) costs, the levelized cost of energy (LCOE) metric, for a 10 MW installation, is determined to be between NZ$176 and NZ$237 per MWh, with total electricity generation over 25 years between 263 and 353 GWh. In order to reach the required LCOE value of less than NZ$100/MWh for utility scale generation, the EPC costs will have to be reduced by a factor of 2 to around NZ$1,500/kWp.

The Influence of Water Temperature on the Hydrogeochemical Composition of Groundwater during Water Extraction and Reinjection with Geothermal Heat

This study presents a simulation of potential changes in groundwater in three wells within a Quaternary gravel aquifer in the city of Ljubljana when groundwater cooled by about 4 °C is reinjected into it. The research focuses on the mass transport of calcite in the vicinity of boreholes. According to our results, the impact of the changes in the geochemical composition of the water is relatively small (around 1%). Although the waters are approximately in equilibrium, calcite may be dissolved and sometimes precipitated within the aquifer when cooled water is reinjected into it. The amounts of precipitated calcite always decrease with decreasing temperatures of the reinjected water, which can lead to calcite dissolution if the temperature difference is large enough and the water is only slightly oversaturated. This novel finding is significant since previously published studies have mostly focused on understanding the scaling (precipitation) of calcite and not its dissolution. The mass transfer of calcite is relatively low, but in a scenario of long-term pumping for several years, such low values could lead to a dissolved or precipitated mass of several hundreds of kilograms of calcite per year (at a pumping rate of 46 L/s).

Arctic Ocean temperatures

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Study on the performance of a novel dew-point evaporative cooler based on fiber membrane automatic wicking

A dew point evaporative cooler with fiber membrane coated in the wet channel for improving wettability was proposed in this paper. Firstly, Coolplus with the best performance was selected by comparing four kinds of fiber materials. Then, the cooling performance of the cooler was studied at different experimental conditions. It was found that the cooler showed excellent cooling effect at high temperature, low humidity and velocity. The temperature was decreased slowly along the flow direction of primary air. When inlet temperature, relative humidity and velocity were in the range of 25∼40, 40%∼70% and 1 ∼ 2m/s at the condition of 14 water temperature, the maximum temperature drop was 8.35, the cooling capacity per unit area was between 59.7 and 149.4W/m2, and the wet bulb efficiency and dew point efficiency was increased from 42% and 25% to 92% and 76%. When the water temperature was raised from 14 to 28, the temperature drop was only decreased from 8.35 to 6.82. Therefore, the influence of water temperature on the cooling effect is insignificant. The best conditions of temperature 40, relative humidity 40%, velocity 1m/s and water temperature 20 were suggested. Finally, comparison with a similar case was conducted to evaluate the proposed cooler.

Ventilation and cooling of coal mining face based on CFD model optimization

To solve the problem of high temperatures at the coal mining workings site. The CFD model of the coal mining face was optimized by importing user-defined functions (UDF) in ANSYS-Fluent and simulating the gas-liquid two-phase flow. By analyzing different ventilation variables, an air volume of 36.81 m3/s and an air temperature of 298 K were determined as the optimum ventilation parameters. Based on dynamic multi-field coupling analysis, a spray cooling system was proposed. The influence of water temperature, height, different zones, and spray group spacing on the cooling effect is analyzed by numerical simulation. The results show that the best effect is achieved when the water temperature is 286 K and the group spacing is 10 m. At this point, the peak temperature of a single group on the pavement side is 0.5–1 ℃ lower than the conventional temperature. The maximum temperature was 27 ℃, and the minimum temperature was 24.4 ℃. The effect of the system on cooling is even more pronounced during summer ventilation.

Does water temperature influence in microcystin production? A case study of Billings Reservoir, São Paulo, Brazil

We investigated the relationship between some water quality parameters and microcystin, chlorophyll-a, and cyanobacteria in different conditions of water temperature. We also proposed to predict chlorophyll-a concentration in the Billings Reservoir using three machine learning techniques. Our results indicate that in the condition of higher water temperatures with high density of cyanobacteria, microcystin concentration can increase severely (>102 μg/L). Besides the magnitude observed in higher concentrations, in water temperatures above 25.3 °C (classified as high extreme event), higher frequencies of inadequate values of microcystin (87.5%), chlorophyll-a (70%), and cyanobacteria (82.5%) compared to cooler temperatures (<19.6 °C) were observed. The prediction of chlorophyll-a in Billings Reservoir presented good results (0.76 ≤ R2 ≤ 0.82; 0.17 ≤ RMSE≤0.20) using water temperature, total phosphorus, and cyanobacteria as predictors, with the best result using Support Vector Machine.

Effect of thermo-velocity barriers on fish: influence of water temperature, flow velocity and body size on the volitional swimming capacity of northern straight-mouth nase (Pseudochondrostoma duriense).

Water temperature and flow velocity directly affect the fish swimming capacity, and thus, both variables influence the fish passage through river barriers. Nonetheless, their effects are usually disregarded in fishway engineering and management. This study aims to evaluate the volitional swimming capacity of the northern straight-mouth nase (Pseudochondrostoma duriense), considering the possible effects of water temperature, flow velocity and body size. For this, the maximum distance, swim speed and fatigue time (FT) were studied in an outdoor open-channel flume in the Duero River (Burgos, Spain) against three nominal velocities (1.5, 2.5 and 3m s-1 ) and temperatures (5.5, 13.5 and 18.5°C), also including the changes between swimming modes (prolonged and sprint). Results showed that a nase of 20.8cm mean fork length can develop a median swim speed that exceeds 20.7BL s-1 (4.31 m s-1 ) during a median time of 3.4s in sprint mode, or 12.2BL s-1 (2.55 m s-1 ) for 23.7s in prolonged mode under the warmest scenario. During prolonged swimming mode, fish were able to reach further distances in warmer water conditions for all situations, due to a greater swimming speed and FT, whereas during sprint mode, warmer conditions increased the swim speed maintaining the FT. In conclusion, the studied temperature range and flow velocity range influence fish swimming performance, endurance and distance travelled, although with some differences depending on the swimming mode. The provided information goes a step forward in the definition of real fish swimming capacities, and in turn, will contribute to establish clear passage criteria for thermo-velocity barriers, allowing the calculation of the proportion of fish able to pass a barrier under different working scenarios, as well designing of the optimized solutions to improve the fish passage through river barriers.