9421876 Jaffe This ocean sciences technology development project continues development of a 3-dimensional sonar imaging system to be used in zooplankton dynamics and ecological research. Work will be undertaken to fabricate an Optical-Acoustic Submersible Imaging System (OASIS), that will allow tracking of zooplankton diel cycles, migrations and nocturnal activity patters. These behavioral data will help to model predator-prey encounters, euphausiid bioenergetics, and diel vertical migration behavior under realistic environmental conditions. The system will be deployable from a remotely-operated underwater vehicle and will simultaneously record both the target strength (acoustic) and a high resolution optical image. This combined technique will help verify acoustic survey information and allow extrapolation of past and present data. Acoustical backscattering will be correlated to animal orientation and this relationship, as well as other optically verified correlations, will permit a better interpretation of in situ acoustic data. The acoustic system has been deployed successfully. Limited trials with camera imaging systems have also been completed. This work combine these two systems. The optical system is to be operated in a strobe mode, triggered from the sonar imaging system. In this way, when a target is found in the sonar image at the appropriate location, the strobe light will be triggered, and an optical image will be recorded.