SCOPE 42 - Biogeochemistry of Major World Rivers

Foreword

See the rivers how they run
Changeless towards a changeless sea
C. Kingsley 1819-1875

From the beginning of time rivers have received special attention. Cultures that depend on rivers for commerce or as a water resource are particularly vulnerable to changes in quantity and quality of river water. Yet as we come close to the end of the 20th century, it is increasingly obvious that the romantic view of rivers as expressed by Kingsley, and held with great conviction even within the last 50 years, is very far from reality. River transport of chemicals, sediments, organic matter and dissolved nutrients to lakes, inland seas and to oceans appears to have been dramatically increased by man's activities in the last century. Changes in land use, irrigation practices, urban use by an ever increasing population and by industrial plants have altered the quantity and quality of river water.

In 1981 SCOPE initiated an ambitious project entitled 'Transport of Carbon and Minerals in Major World Rivers' and entrusted this vitally important task to Professor Egon T. Degens and the SCOPE/UNEP International Carbon Unit at the University of Hamburg. The project had the objective of assessing riverine discharge of water, dissolved and particulate organic matter, nutrients and minerals into world oceans on local, regional and global scales. This book is an elegant synthesis and summary of an immense amount of data presented and discussed at no less than eight international workshops held from 1982-1988. Most of the workshops were held at sites close to one of the major rivers and involved a spectrum of disciplines and scientists from over twenty countries in an ongoing team effort. Through a combination of data gathering, development of appropriate analytical methodology (both simple and sophisticated), assessment, and synthesis, Professor Degens and his colleagues achieved their objectives. This book is an important synthesis of flows, fluxes and interactions of biogeochemical elements in many important world rivers. It is fortunate that he lived long enough to see this work completed.

The SCOPE/UNEP International Carbon Unit in Hamburg was directed, inspired and sustained by Professor Egon Theodor Degens, a scientist of immense productivity and creativity. His major research interest was in natural organic matter, its composition and cycling in oceans and sediments. However, his many scientific achievements included pioneering work on the largest anoxic basin in the world (in the Black Sea) and in the Red Sea where the first hydrothermal ore deposits on the sea floor were discovered. Later he was associated with the discovery of hydrothermal activity in Lake Kivu. When he became Professor at the University of Hamburg in 1973 he established a research group which focussed on the biogeochemical cycling of elements and man's effect on these processes. In this capacity he trained and inspired many biogeochemists who continue his work around the world.

It was not surprising therefore that Professor Degens became involved with many of the activities in SCOPE's project on biogeochemical cycles. These studies were initiated in 1974 and have focussed on the study of the cycles of carbon, nitrogen, phosphorus and sulphur separately and their interactions with each other. He greatly enjoyed interdisciplinary meetings where ideas were traded and explored. He took upon himself the task of involving all nations in his research efforts. One suspects that, if he were to have listed his contribution to science, the transfer of biogeochemical principles and ideas to scientists from developing countries and the creation of research institutions in many countries as a result of workshop involvement would be among those achievements that gave him greatest pleasure. His contribution to understanding the problems of the environment has been enormous and SCOPE was greatly honoured that he chose to devote part of that effort to SCOPE activities.

J. W. B. STEWART 
Secretary-General, SCOPE