Discipline: Biological Sciences
Subcategory: Pollution/Toxic Substances/Waste
Malya Price - Norfolk State University
Co-Author(s): Faniya Doswell, Norfolk State University, Norfolk, VA
Agricultural water pollution affects the vitality and development of aquatic organisms. Ammonium nitrate is a major source of this pollution which enters the waterways from runoff of fertilizers, causing groundwater contamination and eutrophication in surface water. Previous studies have shown adverse effects of ammonium nitrate to aquatic organisms. This study evaluates potassium nitrate as an environmentally sustainable alternative to ammonium nitrate in commonly used fertilizers for the increased growth and harboring of corn. Pre-metamorphic bullfrog tadpoles are suitable environmental biological indicators because they possess semi-permeable skin which utilizes cutaneous respiration. This investigation used ten Lithobates catesbianus pre-metamorphic tadpoles, in Gosner?s Stages 28-30. The tadpoles were placed in five tanks with 26 L of deionized water. The experimental tanks contained 10 mg/L of ammonium nitrate, 10 mg/L of potassium nitrate, and 12-4-8 fertilizer diluted to the percentages of 0.22-0.07-0.15 and 0.10- 0.03-0.07. The 12-4-8 is the percentage of nitrate, phosphorus and potassium respectively. The tanks were tested for pH, temperature, nitrate levels and development of tadpoles. The mandated amount from the EPA led to 90% mortality rate of tadpoles in the ammonium nitrate tank. The highest toxicity was observed in both fertilizer polluted tanks within the first week of this study. The increasing pH of the fertilizer tank contributed to the mortality rate of 100% within the first week of exposure to the 0.22-0.07-0.15 fertilizer. There was a 90% mortality rate within the first week and 100% mortality rate within the second week of exposure to the 0.10-0.03-0.07 fertilizer. The potassium nitrate tank exhibited 70% mortality rate, inhibited the development of the pre-metamorphic tadpoles, and caused deformities in the tadpoles. The nitrates in all tanks acted as an endocrine disruptor. The internal anatomy analysis of the tadpoles demonstrated that the pollutants, ammonium nitrate and fertilizer, affected the integrity of the liver and intestines. All sources of nitrogen that were evaluated are harmful to aquatic life. The importance of this study exhibits the emphasis in monitoring agricultural pollutants that affects the vitality and development of aquatic organisms. Future work includes testing groundwater samples for nitrate levels to distinguish if the levels are within the EPA standard, perform fluorescent spectroscopy to analyze the water and implement more histological analyses.
Funder Acknowledgement(s): LSAMP
Faculty Advisor: Maureen Scott, firstname.lastname@example.org
Role: ? Conduct Research ? Create a research paper, PowerPoint and poster ? Set up, Operate, and Maintain Laboratory Instruments ? Monitor experiments, make observations, calculate, and record data/results ? Measure compounds and solutions ? Maintain health of Bullfrog Tadpoles ? Monitor, and analyze Bullfrog Tadpoles ? Raise Bullfrog Tadpoles to Adults ? Oral Presentation every 2-3 weeks