AN EFFECT OF WATER HARDNESS IN THE THERMAL RESISTANCE OF THE RAINBOW TROUT, SALMO GAIRDNERII RICHARDSON

1963 ◽  
Vol 41 (5) ◽  
pp. 825-830 ◽  
Author(s):  
David E. Craigie
Keyword(s):  
Thermal Stress ◽  
Rainbow Trout ◽  
Thermal Resistance ◽  
Water Hardness ◽  
Hard Water ◽  
Soft Water ◽  
Effect Of Water ◽  
Saline Waters ◽  
Testing Medium ◽  
History Of

Two groups of Salmo gairdnerii were reared from fertilization in hard and soft waters, and the thermal resistance of the yearling trout was measured for both groups in soft and saline waters at 27, 28, and 29 °C. In all cases a history of rearing in soft water resulted in a greater resistance to thermal stress than did a history of rearing in hard water. Increased salinity of the testing medium resulted in an increase in thermal resistance.

The physiological responses of the rainbow trout to strenuous exercise: interactions of water hardness and environmental acidity

1982 ◽  
Vol 60 (12) ◽  
pp. 3153-3164 ◽  
Author(s):  
Mark S. Graham ◽  
Chris M. Wood ◽  
Jeffrey D. Turner
Keyword(s):  
Rainbow Trout ◽  
Physiological Responses ◽  
Recovery Period ◽  
Water Hardness ◽  
Hard Water ◽  
Soft Water ◽  
Exercise Stress ◽  
Strenuous Exercise ◽  
Physiological Changes ◽  
Acid Ph

Cannulated adult rainbow trout were subjected to 6 min of exercise stress in four different water conditions: hard water ([Formula: see text] as CaCO3), control pH ([Formula: see text]); artificial soft water [Formula: see text], control pH; hard water, acid pH [Formula: see text]; and artificial soft water, acid pH. Physiological changes and postexercise mortalities were monitored over a 12-h recovery period. The physiological responses to exercise stress were qualitatively similar in all treatments and are discussed in detail. At control pH, water hardness had minimal influence on the magnitude of physiological response and postexercise mortality. When fish were exercised in hard water at acid pH, the symptoms of postexercise acidosis were actually ameliorated slightly and there was no increase in mortality. However, acid exposure in soft water greatly exacerbated most of the postexercise disturbances and caused a doubling of mortality.

Zinc Influx Across the Isolated, Perfused Head Preparation of the Rainbow Trout (Salmo gairdneri) in Hard and Soft Water

1988 ◽  
Vol 45 (12) ◽  
pp. 2206-2215 ◽  
Author(s):  
Douglas J. Spry ◽  
Chris M. Wood
Keyword(s):  
Steady State ◽  
Rainbow Trout ◽  
Hard Water ◽  
Soft Water ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
First Order ◽  
Scanning Electron Micrography ◽  
Primary Substrate ◽  
Stimulation Of

At a waterborne [Zn] of 1.9 mg∙L−1 in hard water (~1 mmol Ca∙L−1), Zn influx across an isolated, saline-perfused head preparation of rainbow trout (Salmo gairdneri) was about 1.5 nmol∙kg−1∙h−1 through the lamellar pathway and about 1 nmol∙kg−1∙h−1 through the filamental route. Flux rates came rapidly to steady state in both pathways. Trout preexposed to artificial soft water (~0.05 mmol Ca∙L−1) for 5 d showed differential stimulation of flux rates to about 42 and 5 nmol Zn∙kg−1∙h−1 through the lamellar and filamental pathways, respectively. Under these conditions, steady-state fluxes across the lamellae did not occur until 15–20 min after the start of perfusion. Preparations from hardwater-acclimated trout tested in soft water gave typical hardwater fluxes showing that these changes in influx were not simply due to acute exposure of the gill surface to low waterborne [Ca]. Influxes in softwater trout, studied over [Zn] from 0.4 to 7.5 mg Zn∙L−1, revealed a saturable, first-order uptake with apparent Jmax and Km of 150 nequiv∙kg−1∙h−1 and 1.5 mg Zn∙L−1 (23 μmol∙L−1), respectively. Because the apparent Km is in the toxic range, Zn is clearly not the primary substrate. Scanning electron micrography revealed hypertrophy and increased apical exposure of chloride cells; this stimulation, coupled with the increase in Zn influx, suggests that chloride cells may be the site of entry of Zn across the gill.

The Influence of Calcium on the Physiological Responses of the Rainbow Trout, Salmo Gairdneri, to Low Environmental pH

1980 ◽  
Vol 88 (1) ◽  
pp. 109-132
Author(s):  
D. G. McDONALD ◽  
H. HŌBE ◽  
C. M. WOOD
Keyword(s):  
Rainbow Trout ◽  
Calcium Concentration ◽  
Physiological Responses ◽  
Hard Water ◽  
Low Ph ◽  
Soft Water ◽  
Salmo Gairdneri ◽  
Minor Depression ◽  
Regulatory Failure ◽  
A Minor

The physiological responses of 1- to 2-year-old rainbow trout to low pH are dependent on the environmental calcium concentration. Trout, maintained for 5 days in moderately hard water ([Ca2+] = 1·6–2·7 m-equiv/1) at a mean pH of 4·3, developed a major blood acidosis but exhibited only a minor depression in plasma ion levels. In acidified soft water ([Ca2+] = 0·3 m-equiv/1), only a minor acidosis occurred, but plasma ion levels fell and there were substantially greater mortalities. Lethal bioassays performed on fingerling trout over a range of pH levels (3·0–4·8) revealed an important influence of external [Ca2+] on resistance to acid exposure. Terminal physiological measurements on adult fish succumbing to low pH in soft water indicate the singular importance of iono-regulatory failure as the toxic mechanism of action under these circumstances.

Water Quality Modifies Uptake of Waterborne Methylmercury by Rainbow Trout, Salmo gairdneri

1983 ◽  
Vol 40 (6) ◽  
pp. 824-828 ◽  
Author(s):  
D. W. Rodgers ◽  
F. W. H. Beamish
Keyword(s):  
Water Quality ◽  
Rainbow Trout ◽  
Mercuric Chloride ◽  
Relative Efficiency ◽  
Zinc Sulphate ◽  
Hard Water ◽  
Soft Water ◽  
Salmo Gairdneri ◽  
Calcium Dependent ◽  
Sublethal Concentrations

We measured the efficiency of uptake of waterborne methylmercury relative to oxygen consumption for rainbow trout, Salmo gairdneri, in hard or soft water and during exposure to sublethal concentrations of mercuric chloride or zinc sulphate. The relative efficiency of methylmercury uptake in soft water was more than double that measured in hard water. When mercuric chloride was added with waterborne methylmercury, uptake efficiency was further increased, with similar values obtained in hard and soft water. In contrast, addition of zinc sulphate decreased the relative efficiency of methylmercury uptake. Water quality thus significantly affects the accumulation of waterborne methylmercury by fish. In particular, calcium-dependent changes in gill permeability may explain elevated methylmercury residues observed in fish from lakes of low alkalinity and pH.

Toxicity of environmental acid to the rainbow trout: interactions of water hardness, acid type, and exercise

1981 ◽  
Vol 59 (8) ◽  
pp. 1518-1526 ◽  
Author(s):  
Mark S. Graham ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
Water Hardness ◽  
Low Ph ◽  
Soft Water ◽  
Activity Level ◽  
Salmo Gairdneri ◽  
Physiological Mechanisms ◽  
Acid Type ◽  
Influence Of Water ◽  
Acid Toxicity

Classical 7-day lethality tests were used to establish the influence of water hardness [Formula: see text], acid type (HCl versus H2SO4) and activity level (rest versus exhaustive exercise) on acid toxicity to fingerling rainbow trout (Salmo gairdneri) at 15 °C. Seven-day mean lethal concentration (LC50) pH's ranged from 4.1 to 4.5. Hardness reduced H2SO4 toxicity at all pH levels during both rest and exericise, but reduced HCl toxicity only at very low pH levels. Hardness increased HCl toxicity at pH's > 3.8. H2SO4 was generally less toxic than HCl, except at pH's > 3.8 in soft water. Exchaustive exercise markedly potentiated H2SO4 toxicity in both hard and soft water except at very low pH levels. Below pH = 4.4–4.6, critical swimming speed declined linearly by about 4% per 0.1 pH unit. Possible physiological mechanisms responsible for these modifying influences and their ecological significance are discussed.

Effect of Water Hardness on Efficacy of Sodium Hypochlorite Inactivation of Escherichia coli O157:H7 in Water

2017 ◽  
Vol 80 (3) ◽  
pp. 497-501 ◽  
Author(s):  
Sara Swanson ◽  
Tong-Jen Fu
Keyword(s):  
Escherichia Coli ◽  
Sodium Hypochlorite ◽  
Water Hardness ◽  
Hard Water ◽  
Free Chlorine ◽  
Total Hardness ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Effect Of Water ◽  
The Impact

ABSTRACT This study examined how the hardness of water affected the efficacy of sodium hypochlorite in inactivating Escherichia coli O157:H7 in water. Water was prepared at different degrees of total hardness (0, 50, 100, 200, 500, 1,000, 2,000, and 5,000 mg/liter CaCO3). Inactivation was assessed at different levels of free chlorine (0, 0.2, 0.5, and 1.0 ppm) at 2 to 4°C and pH 6.5. Thirty milliliters of chlorinated water was inoculated with 6 log CFU/ml of E. coli O157:H7 and allowed to mix for 3, 10, 20, or 30 s. In the absence of sodium hypochlorite, no reduction in counts of E. coli O157:H7 was observed regardless of the degree of water hardness. However, in the presence of hard water, under certain chlorine concentrations and exposure times, the reduction of E. coli O157:H7 in chlorinated hard water was significantly less than the reduction observed in chlorinated deionized water. For example, after exposure to 0.5 ppm of free chlorine for 10 s, E. coli O157:H7 counts were reduced by 4.8 ± 1.4, 2.0 ± 1.3, 1.6 ± 0.7, 0.5 ± 0.7, and 0.0 ± 0.1 log CFU/ml in water containing 0, 100, 1,000, 2,000, and 5,000 mg/liter CaCO3, respectively. With the exception of 5,000 mg/liter CaCO3, the effect of water hardness was no longer visible after 20 s of exposure to 0.5 ppm of free chlorine. Also, hard water significantly lowered the efficacy of sodium hypochlorite at 3 s of exposure to 1.0 ppm of free chlorine. But after 20 s of exposure to 1.0 ppm of free chlorine, the impact of water hardness was no longer observed. This study demonstrated that water hardness can affect the germicidal efficacy of sodium hypochlorite, and such an impact may or may not be apparent depending on the condition of the solution and the treatment time at which the observation is made. Under the conditions typically seen in commercial produce washing operations, the impact of water hardness on chlorine efficacy is likely to be insignificant compared with that of organic load.

scholarly journals Correlation between water hardness and cardiovascular diseases in Mostar city, Bosnia and Herzegovina

2014 ◽  
Vol 12 (4) ◽  
pp. 817-823 ◽  
Author(s):  
Nevenka J. Knezović ◽  
Mustafa Memić ◽  
Mirela Mabić ◽  
Jasna Huremović ◽  
Ivanka Mikulić
Keyword(s):  
Human Subjects ◽  
Water Hardness ◽  
Population Group ◽  
Hard Water ◽  
Soft Water ◽  
Washington Dc ◽  
Significance Level ◽  
Chi Squared ◽  
Statistical Program ◽  
Physical And Chemical

The aim of this study was to determine the association of cardiovascular disease (CVD) of selected human subjects with the hardness of water they consume. Laboratory testing of physical and chemical parameters of water were made using standardized methods: Standard Methods 19th edn, 1995 (APHA, AWWA & WEF, Washington, DC), and ISO 7888:1985, ISO 10523:1998. Pearson's chi-squared test was used for the statistical analysis of data, with the significance level of 0.05. The obtained data were analysed using the statistical program SPSS 16.0. The study sample consisted of 1,021 individuals divided into two groups: soft water consumers, 603 individuals, and, hard water consumers, 618 individuals. Results indicate that a statistically significant (χ2 = 5.315; df = 1; p = 0.021) number of individuals with CVD drink soft water. The prevalence of CVD in the age group 45–60 years in the study area where soft water is consumed was 21.3% and in the study area where hard water is consumed the prevalence of CVD was 13.7%. The summary results indicate significant correlation between the prevalence of CVD in the population group who drink soft water. The value of the relative risk is 1.127.

The Natural History of an Ovoviviparous Snail, Viviparus georgianus (Lea), in a Soft-Water Eutrophic Lake

1982 ◽  
Vol 1 (4) ◽  
pp. 2-17 ◽  
Author(s):  
Eileen H. Jokinen ◽  
Jeffrey Guerette ◽  
Robert W. Kortmann
Keyword(s):  
Natural History ◽  
Eutrophic Lake ◽  
Soft Water ◽  
History Of ◽  
Viviparus Georgianus

Effect of water hardness on surface tension and dilational visco-elasticity of sodium dodecyl sulphate solutions

2012 ◽  
Vol 377 (1) ◽  
pp. 1-6 ◽  
Author(s):  
V.B. Fainerman ◽  
S.V. Lylyk ◽  
E.V. Aksenenko ◽  
N.M. Kovalchuk ◽  
V.I. Kovalchuk ◽  
...  
Keyword(s):  
Surface Tension ◽  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Water Hardness ◽  
Effect Of Water
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