The papers at the General Symposia of the Joint Oceanographic Assembly were presented by authors who had been invited to deal with topics of broad interdisciplinary interest. Together they gave a valuable account of the present state of marine research, its proQlems and potential. There seems merit in publishing them in one volume and we are grateful to the authors who kindly agreed to prepare their papers for publication. This has taken some time (and not all authors found it possible) but we hope the resulting volume is still indicative of trends in modern oceanography. Particularly noticeable is the way in which the applied aspects are beginning to play a more important part in spite of worries about the effects of the Law of the Sea on our freedom to make observations. We are especially grateful to the four authors who agreed to give lectures summarising the work in their own field which was reported at the Assembly. We also wish to thank the other authors, as well as all concerned with the Assembly and with the production of this volume.

The continental shelf seas have an importance which is out of proportion to the rela tively small fraction of the area of the global ocean which they occupy. These shallow seas play an important role as the high energy boundary zones of the deep ocean where much of the ocean's tidal and wave energies are dissipated. They are highly productive biologically and are responsible for most of the world's fishery production. In many cases, they are also sources of economically important resources, notably hydrocarbons and they are frequently important as thorough fares for merchant shipping. Because they are the regions of the ocean closest to our centres of population and industrial activity, they have been the first to feel the impact of the increasing pressures imposed by large scale waste disposal into the ocean. The North Sea is an archetypal representative of such seas: we need to be able to understand its processes and predict them if we are to achieve a degree of rational management in the future, as the environmental threats increase. The understanding required extends through a wide range of processes that operate in the shelf seas from the fundamental physics to the chemistry and biology of the water column and the seabed sediments. These processes, and the interactions between them, cut across the traditional discipline boundaries within marine science and require a substantial inter disciplinary effort for their effective study.

The continental shelf seas have an importance out of proportion to the reatively small fraction of the area of the global ocean which they occupy. These shallow seas play and important role as the high energy boundary zones of the deep ocean where much of the ocean's tidal and wave energies are dissipated. The North Sea is an archetypal representative of such seas. This text brings the principal results from the North Sea Project which were presented at a discussion meeting organized by the Royal Society. It argues that we should understand and predict the processes of the North Sea in order to achieve a degree of rational management in the future, as environmental threats increase.

Throughout his life Lewis Fry Richardson made many inspirational contributions to various disciplines. Often his ideas were ahead of contemporary thinking, and preceded the technical means necessary for their practical implementation. He is best known for his wealth of important work on meteorology, and his groundbreaking application of mathematics to the causes of war, though his field of interest was in no way limited to these topics, and various aspects of psychology and mathematical approximation also benefited from his unique approach. The originality of Richardson's research can be seen in this collection of all his important papers in the behavioural sciences.