Influence of water hardness on fluoride toxicity to rainbow trout

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.

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Influence of Water Hardness, pH, and Alkalinity on the Mechanisms of Copper Toxicity in Juvenile Rainbow Trout, Salmo gairdneri

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f86-186 ◽

1986 ◽

Vol 43 (8) ◽

pp. 1488-1496 ◽

Cited By ~ 122

Author(s):

Darrel Jon Laurén ◽

D. G. McDonald

Keyword(s):

Rainbow Trout ◽

Pure Copper ◽

Copper Toxicity ◽

Water Hardness ◽

Salmo Gairdneri ◽

Sodium Efflux ◽

Juvenile Rainbow Trout ◽

Influence Of Water ◽

Effects Of Ph ◽

High Alkalinity

Juvenile rainbow trout were exposed to 25–400 μg copper∙L−1 for 24 h. Water hardness, pH, and alkalinity were varied independently at a constant [Na+]. Net and unidirectional sodium fluxes were measured in hard and soft, low-alkalinity water and in hard, high-alkalinity water at neutral pH and pH 5.0. In low alkalinity water, Na+ uptake (Jin) was inhibited at copper concentrations as low as 25 μg∙L−1, and sodium efflux (Jout) was stimulated above 100 μg∙L−1. High-alkalinity water significantly reduced the effects of copper on Jin and Jout, but there was no significant effect of increasing water hardness. The effects of pH 5.0 and copper were additive from 25 to 100 μg∙L−1, but a pure copper effect was found from 200 to 400 μg∙L−1. Fish died when they had lost about 50–55% of their exchangeable Na+ pool. Water hardness and alkalinity had no effect on the apparent uptake of copper, but copper uptake was reduced by about 50% at pH 5.0.

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Influence of water chemistry and natural organic matter on active and passive uptake of inorganic mercury by gills of rainbow trout (Oncorhynchus mykiss)

Aquatic Toxicology ◽

10.1016/j.aquatox.2004.11.013 ◽

2005 ◽

Vol 72 (1-2) ◽

pp. 161-175 ◽

Cited By ~ 49

Author(s):

Joel Klinck ◽

Michael Dunbar ◽

Stephanie Brown ◽

Joel Nichols ◽

Anna Winter ◽

...

Keyword(s):

Organic Matter ◽

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Water Chemistry ◽

Natural Organic Matter ◽

Inorganic Mercury ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Influence Of Water

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Influence of Water Hardness and Co-applied Herbicides on Saflufenacil Efficacy

Crop Management ◽

10.1094/cm-2012-1213-01-rs ◽

2012 ◽

Vol 11 (1) ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Jared M. Roskamp ◽

Gurinderbir S. Chahal ◽

William G. Johnson

Keyword(s):

Water Hardness ◽

Influence Of Water

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Toxicity of TFM (Lampricide) to Six Early Life Stages of Rainbow Trout (Salmo gairdneri)

Journal of the Fisheries Research Board of Canada ◽

10.1139/f73-176 ◽

1973 ◽

Vol 30 (8) ◽

pp. 1047-1052 ◽

Cited By ~ 6

Author(s):

L. E. Olson ◽

L. L. Marking

Keyword(s):

Rainbow Trout ◽

Early Life ◽

Natural Waters ◽

Life Stage ◽

Water Hardness ◽

Salmo Gairdneri ◽

Life Stages ◽

Early Life Stages ◽

Margin Of Safety ◽

Coexisting Species

The lampricide TFM (3-trifluoromethyl-4-nitrophenol) was tested against the following life stages of rainbow trout (Salmo gairdneri): green eggs, eyed eggs, sac fry, swim-up fry, fry, and fingerlings in four water hardnesses (12, 44, 170, and 320 mg/liter as CaCO3). The eyed-egg stage was one of the most resistant stages tested, and the sac-fry stage was one of the least resistant. Increased water hardness decreases toxicity to all stages. The LC50’s range from 0.532 mg/liter to 40.0 mg/liter depending upon life stage, water hardness, and duration of exposure. The margin of safety for coexisting species exposed to TFM ranges from 3.2 to 4.1 in natural waters. The margin of safety for early life stages of rainbow trout and larval lamprey under controlled laboratory conditions ranges from 4.2 to 12.2. Therefore, all six early life stages of rainbow trout are safe in minimum lampricidal concentrations of TFM.

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