Oceans 2020: Science, Trends, and the Challenge of Sustainability

By John G. Field and Gotthilf Hempel

Oceans 2020 presents a comprehensive assessment of the most important science and societal issues that are likely to arise in marine science and ocean management in the next twenty years. Sponsored by the Intergovernmental Oceanographic Commission (IOC), the Scientific Committee on Oceanic Research (SCOR), and the Scientific Committee on Problems of the Environment (SCOPE), the book brings together the world's leading ocean scientists and researchers to analyze the state of marine science and technology, identify key scientific issues for sustainable development, and evaluate the capability of scientists, governments, and private-sector stakeholders to respond to those issues. Topics include: 
 
·         basic ocean sciences
·         pressures on the coastal zone
·         climate change and the ocean
·         fisheries and fishery science in their search for sustainability
·         offshore industries including oil drilling, carbon sequestration, and manganese nodule mining
·         marine information for shipping and defense
 
Also included are chapters on cross-cutting issues including operational oceanography, ocean instrumentation and technology, developing frameworks for cooperation, and capacity building in developing nations. In addition, the book offers an introductory overview and a "Vision to 2020" that outlines a path to rational ocean governance. In each chapter, contributors give a brief but comprehensive overview of the subject and then consider what has been achieved in recent years, define the problems, outline solutions, and set forth recommendations on the needs for and directions of ocean science in support of sustainable development for the next twenty years.
 
Oceans 2020 suggests what can be done about major marine environmental issues through the better development and application of marine science and technology, focusing on the issues that are most closely related to human and sustainable development. It will help guide countries in developing their marine science and technology strategies and priorities and is an essential source of information for policymakers, government officials, resource managers, scientists, the media, and all those concerned with the current and future health of the oceans.

• Language: English
• Publisher: Island Press
• Release date: Apr 22, 2013
• ISBN: 9781610910972

Book preview

BERNAL

PREFACE

This book is based on the deliberations of a large group of experts in ocean science and ocean management who met in Potsdam, Germany, from October 2 to 6, 1999, to analyze the state of marine science, identify key scientific issues for sustainable development, and evaluate the capability of scientific, governmental, and private sector communities in different parts of the world to respond to these issues. The experts considered what has been achieved in recent years, defined the problems, outlined solutions, and determined the needs for and directions of ocean science in support of sustainable development for the next twenty years.

Scientists from a broad range of ages and from many different countries mixed with other stakeholders representing the management and user community to ensure that both the science and the societal issues were addressed in a realistic, credible, and comprehensive manner. During the workshop the participants considered a set of specially prepared background papers and then broke up into discussion groups to tackle the main issues and crosscutting factors. The authors of this book were participants and used the background papers and records of discussions when subsequently writing their chapters. The aim is to guide countries in developing their marine science and technology strategies and priorities in support of sustainable development to 2020.

We would like to thank sincerely the many people who helped to create this book. We thank the Intergovernmental Oceanographic Commission (IOC), Scientific Committee on Oceanic Research (SCOR), and Scientific Committee on Problems of the Environment (SCOPE) for their sponsorship and their invaluable work behind the scenes, including the efforts of the experts who developed the idea for the Potsdam meeting. We thank the IOC, the German government, the German Science Foundation, and the U.S. National Oceanic and Atmospheric Administration (NOAA) for their generous financial support. We thank the local organizing committee, especially Sabine Luetkemeier and her staff from the Potsdam Institute for Climate Impact Research, and Dr. Christiane Schnack and her colleagues from the Centre for Tropical Marine Ecology in Bremen for their hospitality, efficiency, and enthusiasm. And last but not least we thank the many busy people who took the time to come to the workshop. Many experts unselfishly contributed sections to the different chapters or helped in the process of reviewing and editing, especially Ken Brink and Ken Mann. S. Krishnaswami, Richard Ball, and Eduardo Marone provided helpful comments on early drafts of the introductory chapter.

JOHN G. FIELD

GOTTHILF HEMPEL

COLIN P. SUMMERHAYES

EDITORIAL BOARD FOR PEER REVIEW

Peer review comments on each chapter were provided by an editorial board comprising John Field (University of Cape Town), Gotthilf Hempel (University of Bremen), Elizabeth Gross (SCOR), Véronique Plocq-Fichelet (SCOPE), Patricio Bernal (IOC), Robert Duce (Texas A&M University), Brian Rothschild (University of Massachusetts, Dartmouth), Ilana Wainer (University of São Paulo), Geoff Holland (Consultant, Canada), and Colin Summerhayes (IOC). In addition, the board requested external reviews of all chapters from Ken Brink (Woods Hole Oceanographic Institution) and Ken Mann (Bedford Institute of Oceanography). Science writer Peter Coles (Paris, France) was commissioned to edit the text of draft chapters to ensure that they followed a common format and were written in an easily readable style.

Chapter I

Introduction

Colin P. Summerhayes, John G. Field, and Gotthilf Hempel

The living ocean drives planetary chemistry, governs climate and weather, and otherwise provides the cornerstone of the life-support system for all creatures on our planet, from deep-sea starfish to desert sagebrush.

—Sylvia Earle (1995)

THE OCEANS MATTER

The oceans cover 72 percent of the Earth’s surface and, with an average depth of several kilometers, provide an enormous and varied living space that is mainly hidden. They drive our climate and weather, controlling the global deliveries of heat and freshwater. They provide a livelihood for many millions of people through fishing, exploitation of energy and mineral resources, shipping, defense, and leisure activities. The oceans contribute enormously to the biodiversity of the planet. Sediments from the ocean floor contain a record of life’s evolution, the changing position of the continents, and the past variability of the Earth’s climate. The picture is not always rosy. The oceans pose threats to human life and property through floods, storms, sea-level change, and coastal erosion.

Inevitably, humans and their effects on the marine environment threaten the sea’s natural bounty. Overfishing has led to dramatic declines in many fish stocks. Humankind’s influence on the sea is changing the patterns of biodiversity, probably irrevocably. The seas are being used increasingly for oil and gas exploitation and world trade. Population is rising inexorably, especially in the coastal zone where more than half the world’s population lives. Mounting pressure on fragile coastal systems and coastal seas increases environmental damage. The sea is directly and indirectly used for waste disposal. Most waste eventually ends up in the oceans, affecting marine water quality and the health of the environment and of humans. Runoff from land pollutes coastal seas with fertilizers, pesticides, insecticides, and a growing sheaf of complex chemicals. Some of these appear to disrupt the endocrine systems of organisms by mimicking hormones. Toxic algal blooms are also on the increase, and some coastal seas are suffering from a combination of nutrient enrichment, excessive productivity, and oxygen starvation, which leads to eutrophication. Exotic species are being introduced into coastal waters through the discharge of ballast waters. Global warming is causing widespread bleaching and death of corals. There is growing concern that we are not proving as successful as might be wished in protecting our planet and sustaining our future (Watson et al. 1998).

The picture is not all gloom and doom. For instance, the introduction of effective controls on tanker activity by the International Maritime Organisation has reduced the spillage of oil into the sea from tankers by a substantial amount in recent years. New management principles have evolved in fisheries. Nations have agreed to control the runoff of pollutants from land. This book suggests that we can manage the marine environment in a sustainable way by effectively addressing environmental problems at local, regional, and global levels. Effective management means equipping managers with the best understanding and tools that marine science and technology can provide. Part of that understanding is that we cannot continue to use a sectoral approach to environmental questions. In nature there are complex physical, chemical, and biological linkages between what people commonly see as different environmental issues. These interlinked issues have to be addressed in the future in an integrated manner. In preparing this book we addressed that need for integration by bringing together different science groups dealing with the ocean, fostering dialogue between ocean scientists and ocean managers, and considering broad themes—such as climate or coasts—rather than single scientific disciplines or narrow sectoral issues.

WHAT THIS BOOK IS ABOUT

This book suggests what can be done about major marine environmental issues through the better development and application of marine science and technology. It is for policymakers, government officials, resource managers, scientists, the media, and the public. It provides a clear message about the oceans and gives advice on how to gather and use ocean information efficiently and cost-effectively for a multitude of purposes. It also suggests what to invest in to get the best results. It addresses increasing public concern about the direction, magnitude, and consequences of environmental change, helping to answer such questions as, Is the ocean changing? What is the evidence? Why is it happening? And, So what? The book is designed around a limited set of socially important and scientifically exciting issues addressed through chapters illustrated by case histories conveying important messages.

In keeping with the drive for integration, the book focuses on major topics of interest to broad and fairly well-defined groups of users. The book is not a comprehensive study of all marine science and technology. Marine geosciences, for instance, get short shrift. Based on a broad appreciation of societal concerns, the core of the book comprises chapters on basic ocean sciences, coastal research, climate, fisheries, ocean industries, and shipping and navigation. These are complemented by chapters on crosscutting issues, including operational oceanography, ocean instrumentation, the framework of cooperation, and capacity building. All these are sandwiched between an introduction and the book’s final chapter, A Vision to 2020. In focusing on particular issues, we have had to leave out several important topics; for example, we have deliberately made little mention of polar regions, ice-covered seas, and the problems that go with them.

Why did we write this book? Now and then organizations need to pause, to take stock of where they are, to consider where they would like to be, and to plan a way forward. To meet this basic human need for orientation in a complex world, the Intergovernmental Oceanographic Commission (IOC) of the United Nations Education, Scientific and Cultural Organization (UNESCO) and its sister ocean organization, the Scientific Committee on Oceanic Research (SCOR), a component of the International Council for Science (ICSU), have twice worked together to assess the progress of marine science and technology. The first time was in Ponza, Italy, in 1969 (SCOR 1969), and the second in Villefranche, France, in 1982 (IOC 1984). By calling on the expertise of a large number of scientists, the reports of those meetings helped in their own small way to shape the course of the subject toward the end of the twentieth century. As the new millennium approached, the IOC and SCOR considered that it was time to take stock again, with the aid of the Scientific Committee on Problems of the Environment (SCOPE), another member of the ICSU family. This time, however, the emphasis was to be different. The stocktaking was to be carried out in the context of meeting societal needs and the challenge of sustainable development. For the purposes of this exercise we used the Bruntland Commission definition of sustainable development: Development that meets the needs of the present without compromising the ability of future generations to meet their own needs (UNCED 1987).

Our stocktaking is intended to complement the same kind of exercise that national governments undertake. It will provide an international perspective viewed from three angles: political (advice to governments) through the IOC; environmental (the needs to protect the marine environment) through SCOPE; and scientific (the needs of the international science community) through SCOR. One question raised within this perspective is how developed and developing nations alike can address important ocean issues. That question leads naturally to the issue of the transfer of knowledge and technology to help build the capacity of developing nations to carry out marine science and technology in support of their own sustainable development.

This book is not intended to be an assessment of the present health of the ocean; that would require a much longer and more technical volume. Readers wanting such an assessment are referred to recent publications of the Group of Experts on the State of Marine Pollution (GESAMP 2001a, 2001b). For readers searching for an in-depth assessment of progress in ocean science over the past two decades, we recommend the results of a recent comprehensive review on that topic sponsored by the United States’s National Science Foundation (NSF) and fully reported on the Internet as Ocean Sciences at the New Millennium (http://www.geo-prose.com/decadal/). In contrast to the GESAMP and NSF assessments, Oceans 2020 fills a hitherto unoccupied niche by taking a look at ocean science issues that are most closely related to human and sustainable development.

FORECASTING OCEAN SCIENCE

In writing the science and technology chapters in this book, the authors have peered into the future, extrapolating recent trends to see what might be possible in 2020. The authors were chosen because they are in a good position to see with a fair degree of confidence where present scientific trends are leading. They have considered what we already know and what we still need to know in marine science and technology, bearing in mind the natural variability of the ocean and the Earth system of which it is part. They have also taken account of the many human expectations and pressures on the marine environment and its resources.

How accurate are the forecasts reported in this book likely to be? A similar study of major trends in ocean research up to the year 2000 was held in Villefranche, France, in April 1982 (for more details, see IOC 1984). Unlike the largely issue-based studies in the present book, the previous study was discipline-based. When we compare its predictions with what actually emerged, we find that, on the whole, they were remarkably accurate, not least in singling out two areas of interdisciplinary research with significant potential impact on society: climate research and ecosystem studies.

In ocean physics, the previous workshop forecast the need, met through the World Ocean Circulation Experiment (WOCE), for a global scale hydrographic survey. The workshop foresaw that ocean physics research would increasingly underpin the work of the World Climate Research Programme (WCRP), a prediction fulfilled through the Tropical Ocean Global Atmosphere (TOGA) experiment in the equatorial Pacific, which showed that El Niño events could be forecast. TOGA ended in 1995, leaving us with the operational Tropical Atmosphere Ocean array of buoys, whose measurements underpin these forecasts today. The workshop recognized that the world’s ocean needs to be studied as a whole if we are to understand the global climate system, foreshadowing the development of the WCRP’s new program on decadal Climatic Variability (CLIVAR). And it recognized that a global monitoring system would be required for climate studies, a concept realized with the creation of the Global Ocean Observing System (GOOS) in 1991. Several trends were recognized that continue today, including increased measurements of ocean properties by moored arrays of instruments, nonrecoverable instruments, freely drifting floats, Doppler current profilers on ships, acoustic tomography, and ocean-observing satellites. The workshop foresaw increased demands to model and forecast ocean behavior and properties to improve ocean services for marine operations as well as increased demands for collaboration between oceanographers and meteorologists to improve weather forecasting. Missed were the development of profiling floats, now in widespread use, and of the autonomous underwater vehicles that are just becoming available as research tools.

The previous workshop foresaw a need in ocean chemistry now being met through the Land-Ocean Interactions in the Coastal Zone (LOICZ) project to focus on the fluxes of materials across the coastal zone to establish the influence of rivers on ocean chemical budgets. It saw a need later addressed through the Joint Global Ocean Flux Study (JGOFS) to map the transport, fates, and effects on the environment of carbon dioxide. It saw a need met through major national projects coordinated through the international Inter RIDGE Programme to examine the influence on ocean chemistry of the (then) recent discovery of hydrothermal vents on the deep sea floor. And it saw the need for purposeful tracer experiments, like those later used in WOCE, to supply valuable information on mixing in the oceans.

The workshop recognized the importance of technology in facilitating chemical discovery, foreseeing advances in instruments from outside oceanography that would shape future chemical oceanographic research, especially improvements in (1) gas chromatography/mass spectrometry, enabling the identification of individual organic compounds; and (2) airborne lasers, advancing those chemical studies of the oceans requiring synoptic data. It also foresaw the need for improvements in sampling devices, to enable the collection of progressively larger and uncontaminated samples, and in sensors, to enable the collection of chemical data on the same time and space scales as physical data, a development essential for understanding the control of ocean chemistry by ocean physics.

In ocean biology the previous workshop recognized several key trends that continue today, including giving more attention to the properties and functions of ecosystems and quantifying the role of microorganisms on the flux of organic carbon through marine ecosystems. The structure, dynamics, and cycling of matter in marine ecosystems are now better understood, not least through the efforts of JGOFS and GLOBEC, the Global Ocean Ecosystem Dynamics program. Much research on large-scale processes, aimed at understanding the functioning and structure of the ocean ecosystem, is currently being undertaken through GLOBEC.

The workshop saw a need to relate biological processes to the behavior of the physical system in which the processes take place (now being met, for example, through GEOHAB, the Global Ecology and Oceanography of Harmful Algal Blooms project). A need was seen to study the ecology of communities inhabiting hydrothermal vents. Vent organisms have now been studied using in situ experiments, and some have been brought to the surface at ambient pressure for physiological studies. The workshop called for monitoring processes at the benthic boundary, a need met by the development of long-term observing stations in coastal waters.

In addition, the need was seen for interdisciplinary approaches to improve management of living resources in coastal seas and to apply the findings of biological oceanography to fisheries science. Progress is being made in both areas, too, though there is yet more to be done to develop an ecosystem-based approach to fisheries management.

The workshop attributed the (still ongoing) bottleneck in descriptive biological oceanography to two main factors: the time-consuming process of sorting and identifying catches and the rapidly diminishing number of trained taxonomists.

Many major new discoveries or developments were inevitably not foreseen, including:

Broad areas of the open ocean are iron-limited.

Organisms use chemical signals extensively.

Microbes live buried deep beneath the deep-sea floor.

Ocean color satellites capable of mapping plankton distributions would become widespread in the late 1990s.

Acoustical and archival tags would enable the collection of environmental and behavioral data on pelagic animals.

Molecular probes and DNA technology would be used to unravel the genetic structure of marine organisms and populations.

Marine biotechnology would grow so rapidly.

It will be a pleasant surprise if the predictions made in this book are as good as those made by our predecessors. What our predictions will do is help to set priorities for the investment of effort in the relatively near term.

MARINE SCIENCE IN A CHANGING POLITICAL ARENA

Developments in science or technology are not the only influences on the way in which our science evolves. Social forces play a part too. The United Nations Convention on the Law of the Sea (UNCLOS), which became a treaty in November 1994, gave nations rights over huge extensions of their territories in the shape of exclusive economic zones, the existence of which will have an increasing effect on the ways in which countries study and monitor the oceans.

Since the early 1980s there has been a significant increase in political emphasis on the environment. The United Nations Conference on Environment and Development in Rio de Janeiro in 1992 led to publication of Agenda 21, an agenda for the twenty-first century that calls for improved management and sustainable use of oceans and seas, including the development and implementation of GOOS. Progress against Agenda 21 will be measured at the World Summit on Sustainable Development in Johannesburg in September 2002.

Other changes unforeseen in 1982 included the ending of the cold war, which had a number of unexpected spin-offs for marine science. These included the use of nuclear submarines by civilian scientists under the Arctic ice; the release of formerly confidential ocean data; use of the U.S. Navy’s underwater sound surveillance system (SOSUS) to monitor earthquakes, listen to animals communicating, and monitor acoustic signals for detecting climate change through acoustic thermometry of ocean climate (ATOC); and more widespread development and use of remotely operated and autonomous underwater vehicles.

Societal changes led to positive changes in the climate for science and stimulated more marine scientific and technological advances than our predecessors had dreamed possible. Similar changes, which we cannot foresee, may be expected to generate yet more advances in the next twenty years.

Chapter 2

Ocean Studies

John A. McGowan and John G. Field

Earth is a blue water planet, which satellite photographs so clearly and beautifully demonstrate. This fact has had a powerful influence on the tempo and mode of biological evolution as well as on the development of civilization. Water has special physical properties that facilitate the transport of heat and momentum. The ocean absorbs heat and releases it over decades or even centuries, whereas the atmosphere’s energy release has time delays of only a few weeks. This very slow release allows the ocean to act as a sort of flywheel or governor on climatic variability. The enormous volume of seawater, with its large heat capacity, regulates our climate and can greatly affect climate variability. Geological evidence shows that circulation changes in the past have accompanied large climatic variations. Another important property of water is its power as a solvent. It is a mixture of most of the elements and many compounds. The result is that it is not only salty but denser than fresh water, its density varying from place to place because of large differences in temperature, precipitation, and evaporation.

Life undoubtedly began in a watery medium. Many animal and plant groups left the sea for land during the course of evolution, but only a few have been successful in maintaining themselves out of water. Many millions of years of evolution took place before there were any terrestrial plants or animals. So, the principal mechanisms of natural selection and speciation must have originated in the ocean. It is even reasonably certain, now, that the earth’s atmosphere was once heavily laden with carbon dioxide. The activities of primeval, green, photosynthesizing marine organisms must have removed much of this gas from the air and supplied the oxygen upon which most life depends today. In the process of changing the earth’s atmosphere, marine plankton deposited vast amounts of organic carbon byproducts, including what we now call fossil fuel (Schlesinger 1991). This biologically driven change in the chemistry of the atmosphere also changed the heat balance of the earth and, with it, the wind systems and patterns of precipitation and evaporation. This, in turn, changed the circulation of the oceans. The study of this complex interaction of multiple systems on a vast scale has become the interdisciplinary field of oceanography.

THE SCIENCE OF OCEANOGRAPHY

Academic oceanography was founded as a separate field because of the importance of the oceans to human welfare, the richness of scientific questions, the specialized knowledge required to investigate them, and the sheer scale of processes and events in the ocean. Today most large research universities, and many small ones, include courses in oceanography, and it is possible to obtain advanced degrees in this field. But because the subject matter is so diverse, ranging from atmosphere-ocean heat balance to the physiology of marine microorganisms, there is a lot of pressure to specialize in one of the subdisciplines, while simultaneously recognizing the linkages between them.

The purpose of academic oceanography is not only to transfer knowledge and train practitioners, but also to develop new facts and insight into the structure and functioning of the global atmosphere-ocean system: its chemistry, biology, and long-term history of the lithosphere, hydrosphere, and biosphere.

While the study of living creatures is essential to oceanography, the heart of the science is large-scale physics: the movement of water, current patterns, and water chemistry. Physical oceanography is the study of the physical processes that govern the way the oceans work and interact with the atmosphere. It uses theoretical approaches, modeling, and observational techniques, such as measuring the distribution of properties and currents.

Marine chemistry looks at chemical and geochemical processes, including the physical and inorganic chemistry of seawater and ocean circulation based on stable chemical and isotopic tracers; organic chemistry and natural products chemistry; and the geochemical cycles of carbon, sulfur, nitrogen, and other elements.

Biological oceanography is concerned with the interactions of organisms with one another and with their physical and chemical environment. Research in this field is conducted on a broad spectrum of space and time scales and includes nutrient regeneration, population and community dynamics, primary and secondary productivity, biogeography, and the consequences of climate change to biological systems.

Marine geology and geophysics use both direct observation and theoretical methods to understand processes that alter the earth’s crust and to analyze the long-term history of the ocean and its contents.

Paleoceanography interprets changes in the fossils and chemical composition of deep-sea sediment to reconstruct past conditions in the oceans and atmosphere.

Recently, climate sciences have also come to play a much more intimate role in oceanographic research and teaching. The growing realization of the powerful connections between atmosphere and ocean have made it essential to reach a better understanding of these interactions and their importance to the biogeochemistry of the seas. Studies focus on large atmosphere-ocean perturbations such as El Nino, La Niña, decadal shifts, and global warming.

Academic oceanography has seen much real progress in the past twenty years or so. We know much more about why the ocean is the way it is. But, now we must find out whether the ocean is changing; the direction, rate, and magnitude of the change; and the consequences to the planet and its living systems, including humans. This organizing conception is very rapidly evolving into a quest to understand very large-scale earth systems.

What follows is a summary of the larger basic research programs of the past twenty years. Although the programs focus on very different questions, they have a coherent theme: climate-ocean variability and change.

OCEAN CIRCULATION

Thermohaline Circulation

The movement of water in the oceans is influenced by the earth’s rotation, by winds driving the ocean surface, and by the internal distribution of density. In many ways, it is difficult to distinguish cause and effect in the density patterns. However, the consequences of the ocean’s variations in density from place to place are profound. In addition to being linked to the horizontal flow of water in the surface currents, the density distribution is linked to a globally connected system of deeper currents known as the thermohaline circulation (because of its dependence on temperature and salinity) (figure 2.1). The thermohaline circulation involves a system in which warm surface water is cooled at high latitudes and sinks to fill the deep basins of the global ocean with water at close to 0°C (see chapter 4). The key to this circulation is the salt content of seawater, which allows the water density to increase before it freezes.

The main sites for this conversion of shallow salty, warm water to deep, cold water are the Northern Atlantic, the Arctic Ocean, and the Weddell Sea in the Antarctic. This deep and bottom cold water is carried to the Indian Ocean and on to the North Pacific, where it slowly mixes upward to shallow depths, to be transported by the wind-driven upper-level circulation back to the major downwelling regions in the North Atlantic and Antarctica (see figure 2.1 in the color section). This system has been described as a conveyor belt. However, it is in fact a complex system of interlinked and variable currents, whose overall result is to transport heat, water, and other properties around the globe and to maintain the balance of the earth’s climate system.

The sinking water carries with it all of the properties it acquired when it was in contact with the atmosphere, such as gases, atmospheric particles, and the byproducts of biological production (Rahmstorf 1999) (figure 2.2). It also transports huge quantities of dissolved carbon, both as carbon dioxide and organic carbon. The concentration of dissolved carbon dioxide and oxygen in the upper layer of the oceans is on average in equilibrium with the atmosphere. Photosynthesis by phytoplankton in the upper layer removes CO2 in order to synthesize organic compounds. Some phytoplankton also secrete little calcium carbonate (CaCo3) shells or platelets, and these fall out of the upper layer when these plants die. Some of these platelets dissolve in mid-water, but others form vast amounts of calcareous sediment (billions of tons) on the floor of the oceans. Thus, this is one mechanism for sequestering CO2 from the atmosphere to a long-term sink. The phytoplankton also produce dissolved and particulate organic matter. Some of this material simply diffuses downward. This is a second mechanism for the sequestration of CO2 in the deep. Much of the organic matter synthesized by phytoplankton is eaten by small animals, the zooplankton. These animals also produce dissolved and particulate organic detritus. Many animals perform diel vertical migrations, feeding in the upper layers at night and respiring at depths during the day. This is another mechanism for the removal of CO2 from the surface layers. As the upper layer waters move northward, they become chilled and therefore more dense and, in certain areas, sink to great depths. As this water sinks, it carries with it dissolved CO2, organic matter, detritus, and material derived from the atmosphere through fallout or solution. In the case of the formation of North Atlantic Deep Water, the rate of sinking has been estimated to be 15 to 20 million cubic meters per second. Other areas of sinking transport water and materials to intermediate depths. Sinking is the major mechanism for removal of CO2 from the atmosphere via the ocean. The organic material is fed upon at mid-depths by microorganisms and through the process of respiration; they remove much of the O2 and add CO2 to the mid-depth intermediate waters. These waters are greatly oversaturated with CO2 and undersaturated with oxygen. Thus, the intermediate waters of all oceans, the North Atlantic Deep Water, the Antarctic Bottom Water, and the sediment are the greatest reservoirs of carbon on earth. We are still trying to determine the residence times of these sinks, but deeper waters are known to be several hundreds of years old and the sediments much older. The water that sinks must be replaced by upward mixing. Much of this occurs in the interior of the ocean but eventually by upwelling within the upper few hundred meters. Thus, old CO2 is returned to the