scholarly journals Water hardness does not influence iodine-induced mortality of rainbow trout eyed eggs

2021 ◽  
Vol 13 (1) ◽  
pp. 40-44
Author(s):  
J. Rosburg Alex ◽  
Enright Cameron ◽  
M. Voorhees Jill ◽  
E. Barnes Michael
Keyword(s):  
Rainbow Trout ◽  
Water Hardness

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

1973 ◽  
Vol 30 (8) ◽  
pp. 1047-1052 ◽  
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.

Effects of water hardness and pH on vanadium lethality to rainbow trout

1982 ◽  
Vol 16 (10) ◽  
pp. 1479-1488 ◽  
Author(s):  
D.H. Stendahl ◽  
J.B. Sprague
Keyword(s):  
Rainbow Trout ◽  
Water Hardness

The Influence of pH, Water Hardness, and Alkalinity on the Acute Lethality of Zinc to Rainbow Trout (Salmo gairdneri)

1985 ◽  
Vol 42 (4) ◽  
pp. 731-736 ◽  
Author(s):  
R. W. Bradley ◽  
J. B. Sprague
Keyword(s):  
Rainbow Trout ◽  
Water Hardness ◽  
Salmo Gairdneri ◽  
Total Hardness ◽  
Zinc Toxicity ◽  
Carbonate Alkalinity ◽  
Effects Of Ph ◽  
Order Of Magnitude ◽  
Low Toxicity ◽  
Influence Of Ph

The acute lethality of dissolved zinc to rainbow trout (Salmo gairdneri) was significantly increased at higher pH and lower hardness levels. Changes in pH from 5.5 to 7.0 increased zinc toxicity by factors of 2 to 5, depending on total hardness levels. A decrease in hardness from 386 to 31 mg CaCO3/L increased zinc toxicity by more than an order of magnitude at both pH levels. These effects of pH and hardness were not caused by changes in the chemical speciation of zinc. An increase in carbonate alkalinity from 8.4 to 24 mg CaCO3/L at pH 7.0 did not significantly alter zinc toxicity at either hardness level. Thus, carbonate alkalinity is not an important factor at or below pH 7.0. At low hardness, dissolved zinc was more than 10 times as toxic at pH 9.0 as at pH 5.5. Two competing mechanisms appear to operate: as the pH rises, dissolved zinc becomes increasingly toxic, but at higher pH levels it is increasingly replaced by zinc precipitate, which is of very low toxicity to fish.

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.

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