The journal Endangered Species Research [1] has published a Theme Section [2] examining the tracking of marine vertebrates in relationship to their oceanic environment. This publication features the papers from the Biologging III [3] conference hosted by TOPP in September, 2008. The volume includes fully peer-reviewed papers presented as part of the Biologging III Symposium (Monterey, August 2008) which was co-hosted by the Tagging of Pacific Predators [4] (TOPP) and Tag-a-Giant [5] (TAG) programs. Symposium presentations showcased how the state of the art in biologging technologies was being used to unlock the ecology, physiology and conservation biology of a range of vertebrate species. The papers in the present volume represent the breadth and novelty of the research conveyed at the symposium along with additional related papers submitted independently.