This bioassay is the analysis of the fertilization and the embryological development of Strongylocentrotus purpuratus and Strongylocentrotus franciscanus when exposed to hydrogen sulfide and sodium nitrate at various concentrations. Motor vehicles, fossil fuelburning power plants, nitrogen fertilizers, and sewage dumps are sources of NaNO3. The results that show that S. franciscanus was able to tolerate NaNO3 levels better than S. purpuratus because it had higher fertilization success percentages and higher rates of mitotic division.
Sea urchins are an important part of the marine ecosystem due to their role as scavengers.
The increase and decrease of their population can indirectly and directly affect the ecosystem. The information acquired from the experimentation of chemicals on the embryological development of sea urchins can then be utilized and correlated to other fields of research.