Sensitivity to nitrate and nitrite in pond‐breeding amphibians from the Pacific Northwest, USA

Abstract

Abstract-In static experiments, we studied the effects of nitrate and nitrite solutions on newly hatched larvae of five species of amphibians, namely Rana pretiosa, Rana aurora, Bufo boreas, Hyla regilla, and Ambystoma gracile. When nitrate or nitrite ions were added to the water, some larvae of some species reduced feeding activity, swam less vigorously, showed disequilibrium and paralysis, suffered abnormalities and edemas, and eventually died. The observed effects increased with both concentration and time, and there were significant differences in sensitivity among species. Ambrystoma gracile displayed the highest acute effect in water with nitrate and nitrite. The three ranid species had acute effects in water with nitrite. In chronic exposures, R. pretiosa was the most sensitive species to nitrates and nitrites. All species showed 15-d LC50s lower than 2 mg N-NO 2 -/L. For both N ions, B. boreas was the least sensitive amphibian. All species showed a high mortality at the U.S. Environmental Protection Agencyrecommended limits of nitrite for warm-water fishes (5 mg N-NO 2 -/L) and a significant larval mortality at the recommended limits of nitrite concentration for drinking water (1 mg N-NO 2 -/L). The recommended levels of nitrate for warm-water fishes (90 mg N-NO 3 -/L) were highly toxic for R. pretiosa and A. gracile larvae.

Ecological Characterisation of Streams in Tuscany (Italy) for the Management of the Threatened Crayfish Austropotamobius Pallipes Complex

“…are the main causes of crayfish extinction. In fact, as fishes and amphibians (MARCO et al, 1999), crayfish seem to be sensitive to nitrite concentration (as stated previously by LIU et al, 1995;ROUSE et al, 1995) that with total phosphate are reliable indicators of eutrophication. Others parameters influencing negatively the crayfish survival are ammonium (it is toxic at high concentrations), and silicate (an indicator of runoff from construction, e.g.…”

Fire and amphibians in North America

“…In this stream, ammonium and nitrate levels peaked at 261 ug/L and 61 ug/L, respectively-levels an order of magnitude below lethal concentrations tested on tadpoles of several anurans (Hecnar, 1995;Xu and Oldham, 1997;Jofre and Karasov, 1999;Nebeker, 1999a, 1999b). Some amphibian species have been shown to be sensitive to elevated levels of nitrite, nitrate, or other nitrogenous compounds (Marco et al, 1999;Nebeker, 1999a, 1999b), but how frequently aquatic systems experience these levels is poorly known. Nutrient pulses in streams can occur for up to 5 years after a fire and are regulated by fire intensity, structure and composition of the riparian forest, spring runoff, and summer rains (Rieman and Clayton, 1997;Hauer and Spencer, 1998;Vose et al, 1999).…”

Impacts of ammonium nitrate on survival of tadpoles of the common skittering frog (Euphlyctis cyanophlyctis)

“…To control for the presence of excess unionized ammonia, initial pH was meas-ured in aquaria and found to range from 7.37 to 7.41. The water was not renewed for the entire duration of the experiment, which lasted 18 days; this means that actual ammonium and nitrate concentrations were expected to significantly decrease over time throughout the experiment (Hatch Blaustein, 2003), although Marco et al (1999) did not detect significant variation in nitrate levels after 7 days in experimental aquaria. All reference to experimental levels in the present paper refers to nominal values.…”