Datasets associated with “Can slowing the rate of water temperature decline be utilised to reduce the impacts of cold water pollution from dam releases on fish physiology and performance?”

UQ eSpace ◽  
2021 ◽  
Author(s):  
M. A. Parisi ◽  
C. E. Franklin ◽  
R. L. Cramp
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
M A Parisi ◽  
R L Cramp ◽  
M A Gordos ◽  
C E Franklin

Abstract Increasingly, cold-water pollution (CWP) is being recognised as a significant threat to aquatic communities downstream of large, bottom-release dams. Cold water releases typically occur during summer when storage dams release unseasonably cold and anoxic hypolimnetic waters, which can decrease the temperature of downstream waters by up to 16°C. Depending on the release duration, these hypothermic conditions can persist for many months. The capacity of ectothermic species to tolerate or rapidly adjust to acute temperature changes may determine the nature and magnitude of the impact of CWP on affected species. This study assessed the impacts of an acute reduction in water temperature on the physiological function and locomotor performance of juvenile silver perch (Bidyanus bidyanus) and examined their capacity to thermally compensate for the depressive effects of low temperatures via phenotypic plasticity. Locomotor performance (Ucrit and Usprint) and energetic costs (routine and maximum metabolic rate) were measured at multiple points over a 10-week period following an abrupt 10°C drop in water temperature. We also measured the thermal sensitivity of metabolic enzymes from muscle samples taken from fish following the exposure period. Cold exposure had significant depressive effects on physiological traits, resulting in decreases in performance between 10% and 55%. Although there was partial acclimation of Ucrit (~35% increase in performance) and complete compensation of metabolic rate, this occurred late in the exposure period, meaning silver perch were unable to rapidly compensate for the depressive effects of thermal pollution. The results of this study have substantial implications for the management of cold water releases from large-scale dams and the conservation of native freshwater fish species, as this form of thermal pollution can act as a barrier to fish movement, cause reduced recruitment, ecological community shifts and disruptions to timing and success of reproduction.


Author(s):  
Ramkumar RAMAKRISHNAN ◽  
Ragupathy ARUMUGAM

Performance  of the coolig tower was analysed with various operating parameters and find the minimum cold water temperature. In this study, optimization of operating parameters was investigated. An experimental design was carried out based on central composite design(CCD) with response surface methodology(RSM). This paper presents optimum operating parameters and   the minimum cold water temperature using RSM method.  The RSM was used to evaluate the effects of operating variables and their interaction towards the attainment of their optimum conditions. Based on statistical analysis, water flow, air flow, hot water temperature and packing height were high significant on cold water temperature, with very low probability values(<0.0001). The optimum operating parameters predicted using  RSM method and confirmed through experiment. 


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. D. Robertson ◽  
J. Gao ◽  
P. M. Regular ◽  
M. J. Morgan ◽  
F. Zhang

AbstractAnomalous local temperature and extreme events (e.g. heat-waves) can cause rapid change and gradual recovery of local environmental conditions. However, few studies have tested whether species distribution can recover following returning environmental conditions. Here, we tested for change and recovery of the spatial distributions of two flatfish populations, American plaice (Hippoglossoides platessoides) and yellowtail flounder (Limanda ferruginea), in response to consecutive decreasing and increasing water temperature on the Grand Bank off Newfoundland, Canada from 1985 to 2018. Using a Vector Autoregressive Spatiotemporal model, we found the distributions of both species shifted southwards following a period when anomalous cold water covered the northern sections of the Grand Bank. After accounting for density-dependent effects, we observed that yellowtail flounder re-distributed northwards when water temperature returned and exceeded levels recorded before the cold period, while the spatial distribution of American plaice has not recovered. Our study demonstrates nonlinear effects of an environmental factor on species distribution, implying the possibility of irreversible (or hard-to-reverse) changes of species distribution following a rapid change and gradual recovery of environmental conditions.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1208
Author(s):  
Ewa Olechno ◽  
Anna Puścion-Jakubik ◽  
Małgorzata Elżbieta Zujko ◽  
Katarzyna Socha

Coffee brews are one of the most popular drinks. They are consumed for caffeine and its stimulant properties. The study aimed to summarize data on the influence of various factors on caffeine content in brews prepared with different methods. The study was carried out using a literature review from 2010–2020. PubMed and Google Scholar databases were searched. Data on caffeine content was collected by analyzing the following factors: the influence of species, brewing time, water temperature, pressure, degree of roast, grinding degree, water type, water/coffee ratio as well as other factors (such as geographical origin). To sum up, converting caffeine content to 1 L of the brew, the highest content is that of brews prepared in an espresso machine (portafilter), with the amount of 7.5 g of a coffee blend (95% Robusta + 5% Arabica), and water (the volume of coffee brew was 25 mL) at a temperature of 92 °C and a pressure of 7 bar, but the highest content in one portion was detected in a brew of 50 g of Robusta coffee poured with 500 mL of cold water (25 °C) and boiled.


Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 975
Author(s):  
Kaiji Suzuki ◽  
Nobuo Ishiyama ◽  
Itsuro Koizumi ◽  
Futoshi Nakamura

Clarifying the combined effects of water temperature and other environmental factors on the species distributions of cold-water fishes is the first step toward obtaining a better understanding of the complex impacts of climate warming on these species. In the present study, we examined the abundance and occurrence of the fluvial sculpin, Cottus nozawae, in response to water temperature along environmental gradients in northern Japan. The abundance survey was conducted in the Sorachi River catchment with two-pass electrofishing with a backpack electrofisher. For the occurrence survey, we carried out one-pass electrofishing in the Sorachi, Chitose, and Tokachi River catchments. Fish sampling was conducted once from July to August 2018 in the Sorachi River catchment, from May to June 2011 in the Chitose River catchment, and from July to September 2012 in the Tokachi River catchment. Generalized linear mixed models (GLMMs) and generalized linear models (GLMs) were used for the abundance and occurrence analyses, respectively. We found that the mean summer water temperature was the most influential factor on the distribution of C. nozawae; the abundance and occurrence were both negatively affected by increased water temperatures. In the occurrence model, occurrence probabilities of 0.9 and 0.5 for C. nozawae corresponded to mean summer temperatures of 12.0 and 16.1 °C, respectively. Furthermore, we identified a combined effect of water temperature and current velocity on the abundance of C. nozawae. The increased mean summer water temperature had a stronger negative effect on C. nozawae abundance under gentle flow conditions. While the precise mechanisms of this combined effect could not be determined in this study, stressors associated with low current velocities may increase their vulnerability to higher water temperatures. Our findings indicate that flow disturbances caused by human activities such as excessive water abstraction may exacerbate the negative impacts of climate warming on populations of C. nozawae in the future.


UQ eSpace ◽  
2020 ◽  
Author(s):  
M. A. Parisi ◽  
R. L. Cramp ◽  
M. A. Gordos ◽  
C. E. Franklin

2018 ◽  
Vol 44 ◽  
pp. 00017 ◽  
Author(s):  
Agnieszka Chmielewska

The article discusses the influence of the cold water temperature on the amount of energy consumed for the purposes of the DHW preparation in multi-family buildings. The article begins with a presentation of the DHW consumption readings from a multi-family building, recorded on a monthly basis during the period of 4 years. The readings constituted the base for calculating the demand for energy for the purposes of the DHW preparation. Subsequently, basing on the output water temperature readings from the water treatment plant, it was proved that the temperature of the mains water fluctuates throughout the year. The review of the available literature, as well as the measurements, confirmed that it is necessary to develop a new model of the cold water temperature that would take into account the type of intake in a water treatment plant. The final part of the article presents how the accepted assumptions about the temperature of the mains water influence the consumption of energy for the purposes of the DHW preparation.


1975 ◽  
Vol 39 (1) ◽  
pp. 93-102 ◽  
Author(s):  
R. M. Smith ◽  
J. M. Hanna

Fourteen male subjects with unweighted mean skinfolds (MSF) of 10.23 mm underwent several 3-h exposures to cold water and air of similar velocities in order to compare by indirect calorimetry the rate of heat loss in water and air. Measurements of heat loss (excluding the head) at each air temperature (Ta = 25, 20, 10 degrees C) and water temperature (Tw = 29–33 degrees C) were used in a linear approximation of overall heat transfer from body core (Tre) to air or water. We found the lower critical air and water temperatures to fall as a negative linear function of MSF. The slope of these lines was not significantly different in air and water with a mean of minus 0.237 degrees C/mm MSF. Overall heat conductance was 3.34 times greater in water. However, this value was not fixed but varied as an inverse curvilinear function of MSF. Thus, equivalent water-air temperatures also varied as a function of MSF. Between limits of 100–250% of resting heat loss the followingrelationships between MSF and equivalent water-air temperatures were found (see article).


2020 ◽  
Vol 9 (12) ◽  
pp. e639128886
Author(s):  
Abubakar Muhammed Dadile ◽  
Abubakar Muhammad Dadile ◽  
Habu Muhammed Dadile ◽  
Nurudeen Mohammed

The study was conducted at Gashua, Yobe State. The weather condition of the area during summer is so terrible to the extent that the majority of inhabitants are searching for ice blocks or cold water to drink in other to feel a bit comfortable. In the school, both teachers and students were not comfortable during summer and winter seasons and these made teaching and learning processes boring. Therefore, the study is aimed at assessing the assimilation and academic performance of students during the vsummer and winter seasons. A random selection of past examination record sheets of students in Yusad secondary school, Gashua was used, and information on their academic performance for summer and winter season were obtain from senior secondary one and two (SS1 and SS2) classes. Ten student record books were selected at random for their academic performance on the subject area of biology. Their scores of the academic performance records were subjected to a descriptive statistics where mean, standard deviation was calculated and Z-test was determined. The results of this study revealed that the summer and winter seasons do not affect the assimilation and results reveals that the academic performance of students varies between - 0.58 in SS1 to - 0.72 in SS2 which means that the summer and winter seasons had no influence on the assimilation and performance of students but might cause inconvenience, unfavorable, disturbance and unsuitable conditions for teaching and learning processes. 


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