Marine algae are rich sources of metabolites that function as defenses against herbivores and have potential applications as pharmaceuticals, agrochemicals, and growth regulating substances. An understanding of how environmental factors contribute to the variability of these products may have important implications and may help determine how man's impact on the nearshore environment will affect the interaction between algae and their predators. Drs. Hay and Fenical will assess how physical and biological stresses interact with the algae's resistance to predation and examine the variability of the process.