Water, acid juvenile

Juveniles exposed to full-strength agricultural drainwater from San Joaquin Valley, California, for 28 days. Drainwater had 48.8 (44-53) mg B/L Leopard frog, Ranapipiens, embryos, through day 4 posthatch Boric acid Soft water 13 mg B/L 130 mg B/L Hard water 22 mg B/L 135 mg B/L Borax Soft water 5 mg B/L 47 mg B/L Hard water 3 mg B/L 54 mg B/L... 

Early studies with electrophysiological techniques (EOG, EEG, electro-encephalogram), by Hara and collaborators, have shown that copper and some other heavy metals suppress or completely block the olfactory response to amino acids that are detected as food odors (e.g. Brown et al. 1982). Sandhal et al. (2004) demonstrated with EOG and EEG that a 7 day exposure of juvenile coho salmon to copper-enriched water led to a reduction or total inhibition in the response to the amino acid L-serine or to the bile acid taurocholic acid. The authors found a significant loss of sensory function (at least 50% lower response than in control fish) at 10 or 20 pg Cu/L. 

Biocidal properties of cyanide in aquatic environments are modified by water pH, temperature, and oxygen content life stage, condition, and species assayed previous exposure to cyanides presence of other chemicals and initial dose tested. There is general agreement that cyanide is more toxic to freshwater fishes under conditions of low dissolved oxygen that pH levels within the range 6.8-8.3 have little effect on cyanide toxicity but enhance toxicity at more acidic pH that juveniles and adults are the most sensitive life stages and embryos and sac fry the most resistant and that substantial interspecies variability exists in sensitivity to free cyanide. Initial dose and water temperature both modify the biocidal properties of HCN to freshwater teleosts. At low lethal... 

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