Ecology and sensory biology of aquatic organisms; chemical signals and communication An understanding of chemical signals in the environment can lead to important insights about the ecology of aquatic organisms. Recent advances in technology provide outstanding opportunities for new discoveries, thus allowing quantification of the associations between hydrodynamic, chemical, and biological factors. Our past work on chemically-mediated interactions between organisms emphasized (1)habitat colonization, (2) predation, (3) motility and chemotaxis in microbes, and (4) chemical signal production and transmission. Current priorities include these same topics, as well as expanding work on predation to remote deep sea habitats while beginning new projects on parasite/host interactions, fertilization and sperm/egg recognition. By rigorously determining the effects of chemical signals on organisms under environmentally realistic conditions, and by integrating these findings within a larger ecological and evolutionary framework, we hope to contribute new theory and information on a wide range of topics in the aquatic sciences. Such broad integrations are intellectually and technically challenging, and our future research will include interdisciplinary investigations on numerous spatial and temporal scales.