Environmental Studies Program


Date of this Version



Environmental Studies Undergraduate Student Thesis, University of Nebraska-Lincoln, 2020.


Copyright 2020 Alexis Jean Polivanov


This investigation will collect data to assist in determining if elevated aquatic phosphate levels affects the metamorphosis rate of larval western barred tiger salamanders (Ambystoma mavortium). Monoammonium phosphate fertilizers are being used on crops in Nebraska (NDA, 2017). This area lines up with the area the western barred tiger salamanders are disappearing from (Damme, 2018). Monoammonium phosphate is made up of nitrogen and phosphate. There have been several studies showing how nitrogen is harmful to amphibians such as this salamander (Griffis-Kyle, 2007) (Griffis-Kyle & Richtie, 2007), but there have not been many showing how phosphate affects amphibian’s metamorphosis in the aquatic environment. Therefore, this investigation will look at how elevated levels of phosphates affects the metamorphosis of larval salamanders. The salamander larvae were obtained from Bessey National Forest. Eight salamanders were selected for the study and placed in individual tanks. This study will incorporate a control and treatment group of salamanders that will be followed through their metamorphosis. After statistically analyzing the data, it was found that only one of the two treatment salamanders showed a correlation between the phosphate level and its metamorphosis. Data obtained did not significantly indicate the effects of elevated phosphate levels on Western salamander metamorphosis.