The Clean Water Act (CWA) requires that wetlands be protected from degradation because of their important ecological functions including maintenance of high water quality and provision of fish and wildlife habitat. However, this protection generally does not encompass riparian areasâ€"the lands bordering rivers and lakesâ€"even though they often provide the same functions as wetlands. Growing recognition of the similarities in wetland and riparian area functioning and the differences in their legal protection led the NRC in 1999 to undertake a study of riparian areas, which has culminated in Riparian Areas: Functioning and Strategies for Management. The report is intended to heighten awareness of riparian areas commensurate with their ecological and societal values. The primary conclusion is that, because riparian areas perform a disproportionate number of biological and physical functions on a unit area basis, restoration of riparian functions along America's waterbodies should be a national goal.
This document is a cooperative effort among fifteen Federal agencies and partners to produce a common reference on stream corridor restoration. It responds to a growing national and international interest in restoring stream corridors.
Though overall cancer incidence and mortality have continued to decline in recent years, cancer continues to devastate the lives of far too many Americans. In 2009 alone, 1.5 million American men, women, and children were diagnosed with cancer, and 562,000 died from the disease. There is a growing body of evidence linking environmental exposures to cancer. The Pres. Cancer Panel dedicated its 2008¿2009 activities to examining the impact of environmental factors on cancer risk. The Panel considered industrial, occupational, and agricultural exposures as well as exposures related to medical practice, military activities, modern lifestyles, and natural sources. This report presents the Panel¿s recommend. to mitigate or eliminate these barriers. Illus.
The importance of salmon to the Pacific Northwestâ€"economic, recreational, symbolicâ€"is enormous. Generations ago, salmon were abundant from central California through Idaho, Oregon, and Washington to British Columbia and Alaska. Now they have disappeared from about 40 percent of their historical range. The decline in salmon numbers has been lamented for at least 100 years, but the issue has become more widespread and acute recently. The Endangered Species Act has been invoked, federal laws have been passed, and lawsuits have been filed. More than $1 billion has been spent to improve salmon runsâ€"and still the populations decline. In this new volume a committee with diverse expertise explores the complications and conflicts surrounding the salmon problemâ€"starting with available data on the status of salmon populations and an illustrative case study from Washington state's Willapa Bay. The book offers specific recommendations for salmon rehabilitation that take into account the key role played by genetic variability in salmon survival and the urgent need for habitat protection and management of fishing. The committee presents a comprehensive discussion of the salmon problem, with a wealth of informative graphs and charts and the right amount of historical perspective to clarify today's issues, including: Salmon biology and geographyâ€"their life's journey from fresh waters to the sea and back again to spawn, and their interaction with ecosystems along the way. The impacts of human activitiesâ€"grazing, damming, timber, agriculture, and population and economic growth. Included is a case study of Washington state's Elwha River dam removal project. Values, attitudes, and the conflicting desires for short-term economic gain and long-term environmental health. The committee traces the roots of the salmon problem to the extractive philosophy characterizing management of land and water in the West. The impact of hatcheries, which were introduced to build fish stocks but which have actually harmed the genetic variability that wild stocks need to survive. This book offers something for everyone with an interest in the salmon issueâ€"policymakers and regulators in the United States and Canada; environmental scientists; environmental advocates; natural resource managers; commercial, tribal, and recreational fishers; and concerned residents of the Pacific Northwest.
Quantitative modeling methods have become a central tool in the management of harvested fish populations. This book examines how these modeling methods work, why they sometimes fail, and how they might be improved by incorporating larger ecological interactions. Fisheries Ecology and Management provides a broad introduction to the concepts and quantitative models needed to successfully manage fisheries. Walters and Martell develop models that account for key ecological dynamics such as trophic interactions, food webs, multi-species dynamics, risk-avoidance behavior, habitat selection and density-dependence. They treat fisheries policy development as a two-stage process, first identifying strategies for varying harvest in relation to changes in abundance, then finding ways to implement such strategies in terms of monitoring and regulatory procedures. This book provides a general framework for developing assessment models in terms of state-observation dynamics hypotheses, and points out that most fisheries assessment failures have been due to inappropriate observation model hypotheses rather than faulty models for ecological dynamics. Intended as a text in upper division and graduate classes on fisheries assessment and management, this useful guide will also be widely read by ecologists and fisheries scientists.
The chapters in this book consider the past and present of education in China, elementary education, vocational education, higher education, adult education, education for ethnic minorities, modern distance education, teacher education and teachers, international exchanges and cooperation, the education funding system, and the study of education as a science.
