The common theme of a report detailing the first large-scale assessment of the health and status and trends of the nation's biological resources is that across the United States land use, water use and invasive species are the three factors most responsible for reported and often dramatic declines in the country's plants, animals and ecosystems, said Dr. Charles G. "Chip" Groat, director of the U.S. Geological Survey, in a keynote speech today announcing the release of the government report.
The two-volume report, Status and Trends of the Nation's Biological Resources, was presented today at the S. Dillon Ripley Center in the Smithsonian Institution in an event sponsored by the U.S. Geological Survey, the National Marine Fisheries Service, the Smithsonian Institute for Conservation Biology, and the White House Office of Science and Technology Policy.
The report was produced by the U.S. Geological Survey with contributions from nearly 200 experts from federal government, academic and nongovernmental communities, including a section on marine resources written by the National Marine Fisheries Service. It synthesizes current information on status and trends of biological resources with a historical perspective of ecosystems across the country to assess how the nation's resources are changing. The report also covers the major factors that affect biological resources nationwide.
The report, said Groat, documents that the major land-use changes negatively affecting the health of biological resources are urbanization, conversion of lands to agriculture, draining of wetlands and the fragmentation of forests. "For example," he said, "in seven states once covered with native grasslands, less than 1 percent of the native tall-grass prairie habitat remains. Losses are due to agriculture, grazing, urbanization and mineral extraction. The result is that native grassland bird species have shown more consistent, widespread and steeper declines than any other group of North American birds."
Likewise, he said, the report details how changes in the nation's waterways to accommodate navigation, irrigation, hydroelectric power generation and municipal use have drastically altered the biological integrity of aquatic environments. The result, he said, is that aquatic organisms dominate lists of imperiled species.
Particularly dramatic examples of the imperilment of aquatic systems occur in the Southeast and the Southwest, Groat said. "In the Southeast, where as many as 144 major reservoirs have been built, the effects of these dams on the wealth of aquatic biodiversity are dramatic -- 19 percent of the freshwater fish species are threatened or endangered, and 73 percent of the freshwater mussels are at risk. And in the Southwest, habitat loss due to dams, groundwater pumping and pollution have contributed to jeopardizing more than 48 percent of the region's fish species."
Groat called invasions by non-native species one of the most important issues in natural resource management and conservation biology today. "Invasive species are especially troublesome because many of them have become established in habitats that have no natural competitors or predators, enabling the invaders to thrive to the extent where they either out-compete native species, significantly alter habitat or both," he said.
In the Great Lakes, for example, the report shows that at least 25 non-native fish species, as well as many other invasive aquatic organisms, have become established, drastically changing the fishery, Groat said. "Similarly, Eastern forests have ben defoliated by gypsy moths; elm and chestnut trees have been decimated by non-native diseases; and a non-native fungus called anthracnose threatens dogwood trees."
The report also notes that non-native species are particularly devastating on island communities, as is evident in Hawaii, where about 90 invasive plant species pose significant threats to the state's ecosystems. Some plants, such as miconia, which locals call "the green cancer," can out-compete native species to create single-species stands or can even alter ecosystem processes.
Citing the decline of Pacific salmon as an example, Groat emphasized that it is often the combination of factors that devastate a resource. Combining land- and water-use changes, non-native species, climate change, environmental contaminants and harvest together is often what is causing the most significant declines in our nation's plants, animals and ecosystems, he said.
"Man's impact on the earth is accelerating," said Groat. "We continue to experience population growth, urban sprawl and heavy use of natural resources -- from lands to waters to air and living creatures. In fact, we will see more and more pressure on all our biological systems. USGS will be in the forefront of identifying new threats and helping to find appropriate solutions before they become widespread problems -- or so severe we cannot restore and maintain our natural heritage. It is clear that we face significant challenges in monitoring the changes in the earth's environments and in filling the gaps in our knowledge. But we also have a great opportunity to address these challenges."
Also speaking at the event was Dr. William W. Fox, Jr., director, Office of Science and Technology, National Marine Fisheries Service at NOAA. Whereas the U.S. Geological Survey conducts research and monitoring for the Department of the Interior in biology, geology, hydrology and mapping, NMFS's Office of Science and Technology conducts research and monitoring on the biological resources found in the nation's oceans.
Fox pointed out that the marine resources of the oceans need the same kind of research and monitoring as biological resources on land. "The status and health of our living marine resources affect commerce and recreational opportunities throughout our coastal oceans. Resource managers can use this and future scientific publications as tools for better planning and direction."
The report called the welfare of the nation's marine resources "guarded," with a need to remain vigilant. According to the National Marine Fisheries Service in the report's Executive Summary, the collapse of some of the nation's fisheries, the poor welfare of some Pacific coast salmon stocks, and serious declines in some marine mammal populations are examples of situations that deserve special attention.
Groat noted that while the United States is blessed with a rich and often amazing diversity of plants, animals and ecosystems, not enough is known about even the baseline status of most of the country's resources.
"Although we know a great deal about some biological resources -- such as birds, large mammals and some fish species -- information is often spotty, incomplete or nonexistent for most taxonomic groups," Groat said. "We don't, for example, know the status and trends of many species of amphibians and reptiles, of invertebrates, of a great number of plants, of smaller mammals, and of the vast majority of ocean dwellers. And yet, information presented in the report gives great cause for concern about certain populations of these lesser studied species."
For example, said Groat, in the Rocky Mountains, western toads now occupy less than 20 percent of their previous range, and prairie dog populations have declined an estimated 98 percent. And in the Southeast, 73 percent of the freshwater mussels are at risk.
The report does document some good news, said Dr. Michael Mac, the USGS project director for the report. For example, efforts to clean up the Great Lakes have been successful in reducing the levels of toxic chemicals, enabling bald eagle populations to recover in the region, and have also reduced excessive amounts of nutrients from the lakes, which, in turn, has sparked the resurgence of burrowing mayfly populations in Lake Erie. In addition, many of the nation's raptor populations are recovering from past declines caused by the pesticide DDT.
"Still," said Mac, "the report documents the status and trends of individual species and particular habitats, which, if lost, can threaten the ecosystem functions on which humans depend. In the face of environmental change, biodiversity may provide the stability that buffers ecosystems."
Status and Trends of the Nation's Biological Resources is available from the United States Government Printing Office. The two-volume report costs $98 and may be ordered by phone at 202-512-1800. The report will soon be available on both a CD-ROM and online through the USGS website (http://www.usgs.gov).
As the nation's largest water, earth and biological science and civilian mapping agency, the USGS works in cooperation with more than 2000 organizations across the country to provide reliable, impartial, scientific information to resource managers, planners, and other customers. This information is gathered in every state by USGS scientists to minimize the loss of life and property from natural disasters, contribute to the sound conservation, economic and physical development of the nation's natural resources, and enhance the quality of life by monitoring water, biological, energy and mineral resources.
The above story is based on materials provided by United States Geological Survey. Note: Materials may be edited for content and length.
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