Senior thesis written for Oceanography 444In this study, dissolved oxygen was measured in Barkley Sound and Effingham Inlet with the use of a CTD and Winkler titrations. Oxygen minimum zones or "dead zones" in the world's oceans can be strongly influenced by circulation patterns. Oxygen is a useful tracer of circulation and long and short term processes that can have serious consequences for macrofauna. Areas of old and newer water in Barkley Sound were identified.University of Washington, School of Oceanograph