The Freshwater Imperative

A Research Agenda

Robert J. Naiman, John J. Magnuson, Diane M. McKnight, Jack A. Stanford

• Publisher: Island Press
• Year: 2013
• Print ISBN:
  9781559634076
  9781559634069
• eBook ISBN:
  9781610910712
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

This volume summarizes the two-year effort of a working group of leading aquatic scientists sponsored by NSF, EPA, NASA, TVA, and NOAA to identify research opportunities and frontiers in freshwater sciences for this decade and beyond. The research agenda outlined focuses on issues of water availability, aquatic ecosystem integrity, and human health and safety. It is a consensus document that has been endorsed by all of the major professional organizations involved with freshwater issues.

1

Fresh Water and the Freshwater Imperative

Importance of Fresh Water to Society

Human society depends on fresh water and the resources associated with it. Freshwater systems provide water for drinking, hydropower, irrigation, cooling, and cleaning; products such as food, plants, and minerals; and services such as recreation, waste purification, transportation, and aesthetics. Nationally and globally there is abundant evidence that freshwater resources are being rapidly depleted and their quality severely degraded. Depletion results directly from consumption as well as from the effects of human actions, direct and indirect, on the environment. Degradation—unfavorable change in distribution, abundance, and quality of water and aquatic ecosystems—represents a threat to the quality of human life, perhaps even to the sustainability of the biosphere and the long-term vitality of human society.¹

Human societies often naively operate as if they have an unlimited capability to alter water resources and the landscape without degrading the ability of those resources to meet human needs. Moreover, societies often act on the erroneous assumption that increasingly complex technology can continue to replace lost ecological values. The rate of degradation of freshwater resources worldwide is alarming (see chapter 2), a reflection of both the acceleration of human-caused environmental change and the sensitivity of freshwater ecosystems to change. Collectively, lakes, rivers, and wetlands integrate all the human and natural activities and events occurring in a watershed. Rivers act as “the arteries of the continents,” and lakes and wetlands act as integrative sensors of air pollution, climate change, and land use change (Degens, Kempe, and Richey 1991). The characteristics of waters, like the characteristics of blood, are diagnostic of the integrity or health of watersheds (Sioli 1975). In addition to being diagnostic, the attributes of fresh waters determine the ultimate success of human and other life.

Of the many uses of fresh water, potable water is perhaps the most crucial resource for the maintenance of human societies. Yet fresh water is limited in total supply, unevenly distributed, and often of unacceptable quality, particularly in areas where supply is limited. Both the quantity and quality of water are shaped by virtually all components of a watershed and by biological and physical processes inherently characteristic of the groundwater, lakes, ponds, rivers, streams, and wetlands within which the water resides.

A complete understanding of the multiple factors influencing water quality and aquatic habitats requires a broad, multidisciplinary approach. Consideration of water as a commodity or resource in isolation from its associated chemical, physical, and biological properties has led to disastrous consequences for managers (National Research Council 1987; Stanford and Ward 1992a; Lee 1993; Oremland 1994). Application of basic principles of aquatic ecology is essential in any comprehensive research plan for the nation’s or world’s fresh water ( Karr 1991; Likens 1992).

Addressing Freshwater Issues

Addressing problems of water resource degradation requires an expanded understanding and evaluation of the nature of freshwater problems. It requires identification and development of appropriate societal responses to mitigate damage to natural resources (figure 1.1), including development and evaluation of restoration techniques. Effective approaches to accomplish these tasks depend on partnerships at several levels: among natural scientists in complementary disciplines, among natural and social scientists, and among scientists, policy makers, and natural resource managers. Partnerships among natural scientists include those spanning traditional physical, chemical, and biological disciplines and addressing the full range of interacting environments, such as groundwaters, lakes, streams, and wetlands and land, oceans, air, and ice. This breadth is encompassed within the science of limnology, or freshwater ecology, the study of inland waters in all their aspects.

Figure 1.1 Interaction of human societies and Natural Freshwater Ecosystems. Ecosystems produce goods and services that are used by society—often at minimal cost—and human activities and waste products may have profound effects on freshwater ecosystems. The management interface is not always effective at ensuring that feedbacks between parts of this system are beneficial.

Partnerships among natural and social scientists are necessary to produce not only high-quality science but also science in its most usable form. Unfortunately, these partnerships have not yet developed into an identifiable transdisciplinary science. However, interactive partnerships among freshwater scientists, policy makers, and resource managers are essential for developing a comprehensive approach to integrating freshwater sciences with management of freshwater systems. Early and continued interaction of scientists, managers, and policy makers will produce useful results that can, through adaptive management and bounded conflict (in the sense of Lee 1993), lead to improved management systems for fresh waters.

Two key challenges faced by freshwater scientists are distinguishing natural from human-induced changes and effectively assessing cumulative effects. These require long-term studies appropriate to the temporal and spatial scales of factors controlling aquatic systems and framing water resource issues. Increasing evidence, for example, suggests that changes in global climate can alter or decrease water resources in complex and poorly predicted ways (Smith 1991; Carpenter et al. 1992; Melack 1992). As freshwater issues become more complex, researchers need to develop the capacity to make predictions on temporal scales of 10 to 100 years and at spatial scales that include air-land-water interactions at the watershed scale (approximately 100 square kilometers) or larger. At broad spatiotemporal scales, interacting effects of numerous agents of change are superimposed. Habitat destruction, deforestation, acid precipitation, eutrophication, toxic pollution, climate change, overfishing, and introduction of exotic species act simultaneously and cumulatively and as such may have effects that exceed those of any single agent of change.

Multidisciplinary Teams in Limnology

Multidisciplinary scientific teams at the Experimental Lakes Area (ELA) in Ontario, Canada, and at Lake Mendota, Wisconsin, have been extraordinarily successful in solving major environmental problems, despite the usual difficulties in understanding complex limnological systems. These North American sites provide models for additional U.S. initiatives. Ecosystem-scale experiments by integrated teams of hydrologists, biologists, geochemists, and soil scientists at the ELA are providing the predictive understanding of natural ecosystems necessary to identify and solve such problems as cultural eutrophication, acidification, and heavy metal pollution. For example, the ELA team has elucidated the effects of specific nutrients on water quality and clarity, providing new insights into the roles of phosphorus and nitrogen, rather than inorganic carbon, in limiting primary productivity in nutrient-poor ecosystems (Schindler 1977). The Wisconsin team manipulated the food web of Lake Mendota to demonstrate how addition of top predators to the lake increased water clarity through the cascading effects of predation (Kitchell 1992), showing that the clarity of eutrophic lakes is controlled by both nutrient inputs and intensity of predation on herbivorous prey.

Other insights from the ELA and Wisconsin studies show that effects of acidity are first seen as changes in species composition of lakes and that microorganisms generating alkalinity in sediments can play a critical role in ameliorating the effects of acid rain on lakes (Schindler et al. 1985). Working with physical and chemical oceanographers, the ELA limnologists unraveled the complex mechanics of gas exchange across the air-water interface, an achievement that was instrumental in understanding these vital processes in the ocean, a major component of the planet’s biogeochemical carbon cycle. These examples underscore an urgent need for a national effort to organize and support teams of scientists from diverse disciplines to address problems involving human-accelerated environmental change in aquatic ecosystems.

This lake in northwestern Ontario, Canada, demostrates the vital role of phosphorus in eutrophication. The far basin, fertilized with phosphorus, nitrogen, and carbon, was covered by an algal bloom within two months. However, no increase in algae or change in species composition was observed in the near basin, which received similar quantities of nitrogen and carbon but no phosphorus (Schindler 1974). (Photo copyright 1974 by the AAAS.)

Currently, the issues surrounding fresh waters on a national scale are more extensive and complex than any one agency or institution can address effectively (Turner et al. 1990; Lee 1993). Unfortunately, long-term watershed-scale or regional-scale studies are not the norm for freshwater sciences. Yet this is the appropriate scale for integration of social, environmental, and economic issues influencing watershed characteristics. It is a scale toward which limnologists and resource managers need to direct more energy and expertise (Naiman 1992).

Because of the massive changes taking place in our aquatic systems and water supplies, only a short time remains for developing a predictive understanding of freshwater ecosystems and their management. Society and its leaders need to work expeditiously to set a positive agenda. To delay threatens the sustainability of the environment and hence the stability of human society. As Kai Lee (1993) warns: “One of the peculiar commonplaces of our time is the realization that civilized life cannot continue in its present form.”

Objective of the Freshwater Imperative Research Agenda

The objective of the Freshwater Imperative (FWI) research agenda is to identify research opportunities and frontiers for inland water ecology (limnology) for the 1990s and beyond. This book is a comprehensive integration of ideas and concerns from recent workshops and symposia on research directions for lake, stream, and wetland science (for example, see Lehman 1986; Carpenter 1988; Stanford and Covich 1988; National Research Council 1991; Firth and Fisher 1992; Naiman 1992). The process of developing the FWI research agenda provided a broad-based opportunity for natural scientists to evaluate the state of knowledge in various disciplines, identify fundamental gaps in knowledge within and among disciplines, suggest program guidelines, identify future research and educational activities, and make specific suggestions for implementation. This book is intended to assist government agencies and private institutions in establishing long-term program directions for freshwater research that relate directly to improved regional watershed-level management and human sustainability.

The FWI research agenda addresses a strategic, long-term goal: to ensure that water resource managers and policy makers have adequate and timely scientific information to protect, utilize, and enhance the nation’s water resources. This book can contribute significantly to the development of a national strategy for freshwater science that includes research, applications and technology transfer, and education and outreach. Such a freshwater science strategy requires an ever-improving infrastructure responsive to the evolving knowledge that eventually can provide a predictive understanding of freshwater resources and ecosystems.

2

Status of Fresh Waters and Challenges Ahead

Degradation of Freshwater Resources

In the United States and other countries, degradation of water resources results in (1) biological impoverishment, (2) altered hydrologic regimes, and (3) risks to human health and quality of life. These three issues highlight the critical need for a freshwater research strategy that defines specific priority areas (figure 2.1). The strategic goal of the Freshwater Imperative is directly related to these issues, as is our opportunity as a nation to develop an ever-improving understanding and management of freshwaters (see chapters 3 and 4). The Freshwater Imperative is especially crucial at this time as the nation faces an unprecedented decline in the quantity and quality of its freshwater systems.

Biological Impoverishment

Biological impoverishment is the antithesis of ecological integrity—maintenance of the physical, chemical, and biological systems necessary for sustaining an acceptable quality of life. Declines in the integrity or health of biological support systems on earth are an ominous signal to human society (Karr 1993). Two major elements constitute ecological systems: the components, as measured by the numbers or types of plants, animals, chemicals, or biomass, and the processes, as measured by the rates of exchange of materials and energy among the components. This concept of biological impoverishment is roughly reflective of biological diversity but is a broader measure than genetic or species diversity.

Biological impoverishment results from human failure to recognize that we depend on the integrity of earth’s life support processes. These biological processes include predation, photosynthesis, gas fluxes, and nutrient availability, as well as a host of other processes related to nutrient cycling, genetics, and reproduction. In addition, physical processes affect the rate of biological processes—for example, water circulation affects algal photosynthesis rates, nutrient supply, and dilution of p...

Table of contents

• About Island Press
• Title Page
• Copyright Page
• Table of Contents
• Table of Figures
• Foreword
• Preface
• Executive Summary
• 1 - Fresh Water and the Freshwater Imperative
• 2 - Status of Fresh Waters and Challenges Ahead
• 3 - Directions for Freshwater Research
• 4 - Linking Research, Management, and Policy
• 5 - Implementation Requirements
• Appendix 1 - FWI Research Agenda Participants
• Appendix 2 - Booksand Proceedings Reviewed by the FWI Steering Committee
• Literature Cited
• Glossary of Terms and Acronyms
• About the Authors
• Index
• Island Press Board of Directors