Freshwater Ecosystems Revitalizing Educational Programs in Limnology (1996) / Chapter Skim
Currently Skimming:
1 Overview: Status of Inland Waters
1 Overview: Status of Inland Waters
Pages 10-23
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 10... ...
In the United States, the passage of the Clean Water Act in 1972 reflected widespread awakening to the deteriorating status of the nation's surface waters. The Clean Water Act set a goal of restoring all U.S.
|
From page 11... ...
It is a multidisciplinary science that draws from all the basic sciences relevant to understanding the physical, chemical, and biological behavior of freshwater bodies. There are numerous subspecialties of limnology based on the application of fundamental sciences such as physics, chemistry, geology, and biology; branches of physical science such as optics, fluid mechanics, and heat transfer; and branches of biological science such as microbiology, botany, ichthyology, invertebrate zoology, and ecology.
|
From page 12... ...
For administrators and teachers of aquatic science, the report recommends ways to strengthen university limnology programs to produce a generation of well-educated citizens, aquatic resource managers, and researchers capable of understanding and alleviating the many sources of water quality degradation. This chapter highlights the status of inland waters and the role of limnologists in improving these waters.
|
From page 13... ...
Continued degradation of surface waters causes substantial economic losses, some of the most significant of which are associated with lost fishing revenues, increased costs for treating drinking water, and lost recreational opportunities. The fishing restrictions and fish consumption advisories common in polluted water bodies jeopardize the multibilliondollar fishing industry.
|
From page 14... ...
, 1,279 fish consumption advisories warning consumers and fishermen to limit intake of certain fish because of contamination were in effect in 47 states in 1993; contaminant levels in fish tissues can be more than a million times those in surrounding water because of the tendency of contaminants to concentrate in species at higher levels of the aquatic food web. The need to provide more advanced levels of treatment for degraded sources of drinking water also has significant costs.
|
From page 15... ...
Consequently, the effects of water quality degradation can be long-lasting and in some cases permanent. Where water resources are scarce, such as in parts of the western United States and other arid areas of the world, contamination of water bodies can threaten the livelihood of surrounding populations.
|
From page 17... ...
This process, known as cultural eutrophication, ultimately results in loss of water clarity, loss of oxygen in bottom waters, and a shift in the food web from valuable game fish to less desirable species. High concentrations of pesticides also may be present in agricultural runoff; fish kills are commonly reported to insurance companies or the EPA when major storms follow pesticide applications (National Research Council, 1992~.
|
From page 19... ...
In the Boundary Waters Canoe Area wilderness in northeastern Minnesota, walleyes and smallmouth bass at one time were stocked in some lakes, where they have taken hold, sometimes to the detriment of native species (Friends of the Boundary Waters Wilderness, 1992~. Scientists have made similar observations in western mountain lakes: 80 percent of alpine lakes in the western United States have been stocked with nonnative species (Bahls, 1992~.
|
From page 20... ...
and organic matter (such as that contained in sewage) cause water quality to deteriorate rapidly through growth of excess algae and loss of dissolved oxygen (Hasler, 1947; Sawyer, 1947; Nlollenweider, 1968~.
|
From page 21... ...
Environmental engineers can design systems for reducing pollutant inputs to a water body; fisheries biologists can determine water quality changes needed to rescue a threatened species of fish; hydrologists can identify water flow patterns influencing the movement of contaminants. However, the full range of actions required to restore a water body can best be identified by interdisciplinary teams of scientists including limnologists with experience in integrating the many factors that influence aquatic ecosystems into a broad picture of the whole system.
|
From page 22... ...
87:1638-1642. Great Lakes Water Quality Control Board.
|
From page 23... ...
1993. Recreation and tourism benefits from water quality improvements: An economist's perspective.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.