Lethal and Sublethal Effects of Nitrogen Fertilizer Ammonium Nitrate on Common Toad ( Bufo bufo ) Tadpoles

Abstract

The impact of elevated ammonium nitrate concentrations onthe survival and development of common toad (Bufo bufo) tadpoles wasinvestigated in the laboratory. 1,704 mg/L and 1,637 mg/L nitrate (equivalentto 2,198.7 mg/L and 2,112.3 mg/L ammonium nitrate) were recorded as 96 h and168 h LC50s respectively. These are well above field levels (10-250 mg/L)observed in freshwater in Britain. The exposure of tadpoles to nominalconcentration of 100 mg/L nitrate for 24, 48, and 72 h caused a significantdecrease in their activity but no clear reduction in food consumption ordelay of the development. In subchronic exposures at the nominalconcentrations of 50 and 100 mg/L nitrate, the metamorphosis started earlierand took less time to complete than in the control. However, some of theresults were equivocal, at 50 mg NO3/L the metamorphs weresignificantly larger than the controls, while at 100 mg NO3/Lmetamorphs were not significantly different from the controls. Certaindeformities and unusual swimming patterns were also found in tadpoles exposedto various concentrations of ammonium nitrate.

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“…These effects for aquatic organisms moved away from toxic effects of pollutant may be deadly or recover quickly (Kuma and Krishnamoorthi, 1983;Yaro By et al, 2005). In the present study, all the deaths were only 10% after transferring 96 h toxicity test survivors to flow through tanks, which is similar with previous reports (Xu and Oldham, 1997;Little et al, 2002).…”

Fire and amphibians in North America

“…For example, Spencer and Hauer (1991) reported phosphorus and nitrogen concentrations in a stream increased 5-to 60-fold over background levels for the first two days after a wildfire in Glacier National Park, Montana. 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.…”

“…Further, amphibians may be less sensitive to ammonia toxicity than fish. Prolonged exposure to elevated levels of ammonium compounds have been shown to have minimal to moderate affects on the survival and development of amphibian embryos and larvae (Hecnar, 1995;Xu and Oldham, 1997;Jofre and Karasov, 1999;Nebeker, 1999a, 1999b) and therefore may only be of concern in smaller lentic water bodies.…”

How Does Changing Pesticide Usage Over Time Affect Migrating Amphibians: A Case Study on the Use of Glyphosate-Based Herbicides in German Agriculture Over 20 Years

“…In addition to the loss of habitats in agricultural areas, agrochemical pollution, which often interacts with other factors like climate change, UV-B radiation, emerging infectious diseases and alien species (Collins and Storfer, 2003;Stuart et al, 2008), is detrimental to amphibians (Mann et al, 2009). The impacts of agrochemicals on amphibians in water bodies (Xu and Oldham, 1997;Relyea, 2009;Biga and Blaustein, 2013) and on land Mann and Bidwell, 1999;Marco et al, 2001;Howe et al, 2004;Cauble and Wagner, 2005;Relyea, 2005;Bernal et al, 2009;Dinehart et al, 2009;Belden et al, 2010;Brühl et al, 2013) have been thoroughly studied and documented (Govindarajulu, 2008;Mann et al, 2009;Relyea, 2011;.…”