Science Serving Maryland's Coasts

Anthony Luz, Cornell University

Class Year: 

Project Title: 

Toxic Effects of Heavy Metal Containing Fertilizers on the Larval Amphibian, Hyla versicolor


Chicken manure-based fertilizers are extremely popular with not only the farming community, but everyday home-gardeners as well. These types of fertilizers are known to contain a suite of heavy metals (As, Ag, Cd, Cr, Cu, Pb, Ni, Se, V, and Zn) and organic compounds. Yet the effects that these contaminants have on the environment have not been well studied in a laboratory setting. For this study, grey tree frogs (Hyla versicolor) were assessed for toxicity to chicken manure-based fertilizer. Hyla versicolor was chosen, due to their availability, rapid developmental period, and their sensitivity to certain toxins. To determine the effects of heavy metals on H. versicolor two controls were set up (one containing sediment consisting of soil, the other containing no sediment), as well as two experimental groups. One experimental group contained sediment consisting of one hundred percent fertilizer, and the other containing an equal mix of fertilizer and soil. The frogs were closely monitored, and by the end of the experiment several heavy metals such as arsenic, copper, and lead were found to have accumulated at significantly higher concentrations in the fertilizer treated groups. However, many biological traits of the frogs were not significantly affected, including metabolic rate, lipid content, and rate of metamorphosis.