Influence of low levels of water salinity on toxicity of nitrite to anuran larvae

Abstract

a b s t r a c tReactive nitrogen compounds such as nitrite (NO -) are highly toxic to aquatic animals and are partly responsible for the global decline of amphibians. On some fish and Caudata amphibian species low levels of sodium chloride significantly reduce the toxicity of nitrite. However, the nitrite-salinity interaction has not been properly studied in anuran amphibians. To verify if chloride (Cl -) attenuates NO -toxicity, eggs and larvae of three anuran species were subjected to a series of NO -solutions combined with three salt concentrations (0, 0.4 and 2 or 0, 0.052 and 0.2 g L -1 NaCl). One of the species tested originated from two different populations inhabiting highly contrasted nutrient richness environments: lowland Doñana Natural Park and Sierra de Gredos Mountain. In general, the presence of Cl -increased survival and growth of lowland Pelophylax perezi and activity of mountain P. perezi larvae exposed to NO -, thus attenuating the toxicity of NO -to developing amphibians. Mountain amphibian populations appeared to be much more sensitive to the concentrations of NO -and Cl -used in this experiment than coastal conspecifics, suggesting possible adaptation of populations to local conditions. Nitrogen pollution in coastal wetlands poses a serious threat to aquatic organisms, causing direct toxicity or indirect effects via ecosystem eutrophication. The presence of low to medium levels of salinity that would be common in coastal wetlands may attenuate the direct effects of increasing concentrations of nitrogenous compounds in water bodies. Furthermore, treating cultures of endangered anurans with small amounts of NaCl may provide an additional protective measure.

Assessment of interactive effects of elevated salinity and three pesticides on life history and behavior of southern toad (Anaxyrus terrestris) tadpoles

“…Water salinity has been shown to influence the toxicity of chemical pollutants in estuarine and marine organisms (reviewed in Hall and Anderson ), but little is known regarding combined effects of elevated salinity and contaminants in amphibians or other freshwater organisms. In tadpoles of Pelophylax [ Rana ] perezi , copper became more toxic with increased water salinity , whereas increased salinity was found to reduce the toxicity of nitrate . Although salinization and pesticides may frequently co‐occur, the combined effects of these 2 stressors on amphibians do not appear to have been addressed previously.…”

Toxic effects of nitrite on freshwater organisms: a review

“…This phenomenon has already been observed in an amphipod (Eulimnogammarus toletanus; Alonso & Camargo 2008), a planarian (Polycelis felina; Alonso & Camargo 2008), two species of crayfish ( Fig. 3; Yildiz & Benli 2004;Koz ak et al 2005) and in amphibians in early development stages (Huey & Beitinger 1980a;Shinn et al 2013). However, it is not known whether there is any effect of chloride on nitrite toxicity to freshwater algae or cyanobacteria.…”

“…) and in amphibians in early development stages (Huey & Beitinger ; Shinn et al . ). However, it is not known whether there is any effect of chloride on nitrite toxicity to freshwater algae or cyanobacteria.…”

“…; Alonso & Camargo ; Shinn et al . ), while the other factors are not addressed in the available literature.…”

A new electrochemical sensor based on carbon paste electrode/Ru(III) complex for determination of nitrite: Electrochemical impedance and cyclic voltammetry measurements

“…Several studies have been conducted recently on the impact of inorganic pollutants such as NO 2 -on water quality [7][8][9][10][11][12][13]. To determine these species, different sensors were developed [14][15][16][17][18][19][20][21][22][23].…”