(full paper is archived in the Miller Library)
Title: The effects of sewage on fertiliztion and early development in Patiria miniata
Student Author(s): Rotkis, Thomas
Faculty Advisor(s): Epel, David
Location: Final Papers Biology 175H
Date: June 1970
Keywords: sewage pollution
Abstract: The gametes, early stages of development, and adult Patiria are all affected by sewage and its associated levels of chlorination. Effects on the adult ranged from an abstinence from feeding behavior in concentrations of sewage greater than 5%, to death within 24 hours when placed near the outfall. The fertilization process was somewhat sensitive to chlorinated sewage. Thus, more than twice as many embryos were able to reach the blastula stage in 10% and 5% sewage solutions if the eggs were fertilized before being placed in the sewage dilutions. Hypochlorite was found to be the active ingredient in chlorinated sewage. The sperm were more sensitive to the hypochlorite than the eggs, showing a reduction in the ability to fertilize eggs in concentrations as low as 0.2 ppm. Because of the high sensitivity of fertilization to both chlorinated and unchlorinated sewage, the ecological effects of the sewage may extend far down current from the damaged area near the outfall.