Document Type

Capstone Project

Degree Name

Bachelor of Science (B.S.)


Science & Environmental Policy


Instrumentation attached to captive marine mammals for open ocean research is an innovative and valuable approach for studying marine mammals in the wild. Direct real-time underwater observations are still needed for a variety of research projects. The goal of this project was to develop and test a system for recording and playback of sea lion dive depth data using the audio channel of an underwater video camera. A pressure transducer was installed into an aluminum waterproof camera housing. A signal conditioning circuit was built to translate pressure (depth) signals into audio signals that could be recorded on the audio channel of the video camera. Designated access to at least one audio channel of the video camera was located. A preliminary decoder circuit was built. The unit was calibrated by submersion to known depths and then placed on a trained California sea lion (Zalophus californianus) for open ocean experiments. The data revealed that the sea lion mainly cruises along the seafloor bottom and breaks the surface roughly every 20 seconds to take a breath.


Capstone Project (B.S.) Earth Systems Science & Policy Institute