Graduation Year


Document Type

Campus Only Senior Thesis

Degree Name

Bachelor of Arts


W.M. Keck Science Department

Second Department

Organismal Biology

Reader 1

Donald McFarlane

Reader 2

Colin Robins

Terms of Use & License Information

Terms of Use for work posted in Scholarship@Claremont.

Rights Information

© 2014 Martha M. Kresz Bierut


Heavy metal pollutants enter watersheds because of deforestation, industrialization, and farming practices. Much research has been done on the Rio Tarcoles watershed, which includes Costa Rica’s capital city of San Jose, but much less has been performed on the Rio Parrita watershed, which lies adjacently South of the Tarcoles. This study aimed to examine the presence of metal pollutants in the Rio Parrita watershed and its possible implications on the wildlife that rely on it. Water and sediment samples were collected during the rainy season at the mouth of the Rio Tarcoles (high pollution control), Quebrada Terciopelo (low pollution control), and Rio Parrita watersheds and analyzed using ICP-MS to determine the concentrations of metallic elements along with the water’s pH and total dissolved solids (TDS). Statistical tests were used to analyze the differences in the availability of select metals in water and sediments that were frequently examined in relevant literature (Al, Fe, U, Cd, Tl, V, Ni, Cr). GIS maps were examined to delineate the watersheds and examine population densities in the Rio Parrita and Rio Tarcoles watersheds. Rio Parrita had significantly greater concentrations of Ni and Cr than either control river (p

This thesis is restricted to the Claremont Colleges current faculty, students, and staff.