The PIs propose to develop an AUV-base blue diode laser system that instantaneously assesses 10-meter vertical distributions (at millimeter resolution) of chlorophyll fluorescence and the kinetics of fluorescence to derive physiological rate measurements at a vertical resolution of millimeters using a streak camera/CCD array. This novel tool will increase the sampling resolutions in regions of high spatial/temporal variability, such as coastal environments, benthic habitats and ice-covered regions. The application of a blue diode laser system to examine vertical distributions phytoplankton distribution and photophysiology will expand our knowledge of complex ocean environments. Characteristics of blue lasers in seawater, the pulse timing, pulse width, peak power, stability, imaging distance, laser frequency spectrum are all areas that may lead to other application is oceanography Finally, the continued challenge to reduce the size and power requirements of oceanographic sensors is illustrated in this proposed work. An improved understanding of phytoplankton dynamics, habitat change and primary productivity in response to environmental forcing in complex ecosystems will translate into improved regional carbon budget estimates. Progress will also be made in understanding the function and efficiency of food webs. Finally, this work continues the effort to apply autonomous systems in the marine environment for increased data density and development of sensor networks that can adequately address the scales of ocean processes.