The microcomputer revolution and the imperative to improve fishery management have accelerated the pace of technological innovation and the application of new technologies to practical fishery management problems. This volume was developed from a symposium held in February 2000, at which scientists working in all oceans of the planet presented research results from diverse marine species and habitats. The proceedings contain the results of research intended to define critical habitat, to monitor behaviour and physiology, and to synthesize tracking results into population models.