Meeting Abstract

S3-1.1  Jan. 4  Visual Ecology on the high seas JOHNSEN, S; Duke University, Durham, NC

Oceanographic research has primarily focused on supra-organismal questions, particularly those involving abundance, distribution and trophic relationships. This approach has been extraordinarily productive and has presently culminated in remote sensing techniques that can map the chlorophyll distribution in the entire planetís surface waters on a daily basis. In contrast, our understanding of the physiology of the species eating this chlorophyll is in its infancy, particularly compared to what is known about coastal and terrestrial species. This is unfortunate, because understanding the physiologies of pelagic species is essential for understanding their distributions, abundance, energy budgets and overall ecology. For example, the respiratory physiologies of crustaceans affect their ability to colonize the oxygen minimum layer, and the different strategies for buoyancy in molluscs have significant effects on energy expenditure. Recently, however, interest in the relationship between the physiology and ecology of pelagic species has increased. A large fraction of this work has centered on sensory physiology, a subfield of which attempts to relate the visual and optical properties of pelagic species to their behavior, distribution, and diversity. This talk discusses three recent advances in the visual ecology of oceanic organisms and identifies several important, but as yet poorly understood issues. A common theme throughout is the highly variable nature of the underwater visual environment compared to most terrestrial environments. Illumination and turbidity levels can change dramatically due to both natural and anthropogenic factors, which has important consequences for predation, mating and other activities. How these changes interact with other physical and biological variables to influence pelagic ecology will continue to be a fruitful area of research.