Date of Award

Spring 2005

Document Type

Legacy Thesis

Degree Name

Bachelor of Science (BS)


Marine Science


College of Science

First Advisor

Susan M. Libes


Species survival is dependent upon an organism's ability to produce viable offspring. Endocrine disrupting chemicals (EDCs) and pollution may impair reproductive success by affecting gamete quality and embryo viability. Reproductive impairment of the sea urchin, Lytechinus variegatus, was investigated in response to atrazine and other pollutants. The criterion for assessing the effect of the chemicals on fertilization was the formation of the fertilization membrane, while the criterion for evaluating the effects on development was the physiology of the pluteus stage. Increasing atrazine concentrations caused a decrease in the fertilization rate and development success of the urchin embryo. Water collected from a local tidal creek known to have high levels of pollutants also caused changes in the fertilization rate and development success. The atrazine concentrations used in this study were selected to determine the effectiveness of the US EPA atrazine criteria for marine echinoderms. A preliminary conclusion shows that the chronic criterion is acceptable while the acute criterion may need to be reduced for Lytechinus variegatus. This work also demonstrates that a long-term study should be done on the effects of the local tidal creek waters on sea urchin embryology.