The publication of this volume on Particle Flux in the Ocean brings to a close a phase of the Global Carbon Cycle project which has concentrated on under-standing the flow, interaction and fate of carbon and other nutrients from land via rivers to lakes and to deep oceans. In 1977 SCOPE, following a meeting in Ratzeburg, Germany, decided to launch a large program on various aspects of carbon cycling. Initially five Units and Subunits were established.