The ocean is a vital component of the metabolism of the Earth and plays a key role in global change. In fact, the oceans cover so much of the Earth's surface that our planet has been described as the Water Planet, and it could be argued that its most extensive ecosystems are marine. Marine ecosystems are inextricably involved in the physical, chemical, biological and societal processes of global change. It is impossible to describe and understand the Earth system without understanding the ocean, the special characteristics of the environment that it provides for life, the changes that it is undergoing and the manner in which these changes interact with the total Earth System. Understanding the functioning of marine ecosystems and how they respond to global change is also essential in order to effectively manage global marine living resources, such as fisheries. The GLOBEC project is an international response to the need to understand how global change will affect the abundance, diversity and productivity of marine populations, from zooplankton to fish, that comprise a major component of oceanic ecosystems. GLOBEC's goal is to advance our understanding of the structure and functioning of such ecosystems, their major subsystems, and responses to physical forcing so that a capability can be developed to forecast the response of marine ecosystems to global change. This volume in the IGBP Science Series, "Marine Ecosystems and Global Change", gives topical examples of the scientifi c problems that GLOBEC is tackling, the innovative approaches adopted, and some selected scientific achievements. It has been written at a time when GLOBEC is in the mid-phase of its implementation. The ultimate achievements of GLOBEC research will be presented in a final synthesis at the end of the project.
