Platte River Assessments for Endangered and Threatened Species Are Scientifically Valid



Read Full Report Date: April 28, 2004 Contacts: Bill Kearney, Director of Media Relations Megan Petty, Media Relations Assistant Office of News and Public Information 202-334-2138; e-mail <news@nas.edu> FOR IMMEDIATE RELEASE Platte River Assessments for Endangered and Threatened Species Are Scientifically Valid WASHINGTON -- Areas along Nebraska's Platte River are properly designated as "critical habitats" for the river's endangered whooping crane and threatened piping plover, says a new report from the National Academies' National Research Council. The committee that wrote the report also concluded that recommendations by the federal government aimed at protecting these and other federally listed species were scientifically valid at the time they were made, although future decisions should be based on newer scientific approaches. The report focuses on the central Platte River, which provides habitat for endangered whooping cranes and interior least terns, as well as threatened piping plovers, and on the lower Platte River, where broad, shallow waters provide important habitat for endangered pallid sturgeon. The Platte River Basin stretches across three states; the North and South Platte Rivers originate in Colorado -- the North Platte flowing through Wyoming -- and meet in Nebraska to form the central and lower Platte River. A series of dams and reservoirs have been constructed throughout the river basin for flood control and to provide water for farm irrigation, power generation, recreation, and municipal use. The alterations to the river and surrounding land caused by this extensive water-control system, however, resulted in habitat changes that were at odds with the protection of the listed species. For example, sparsely vegetated, open, sandy areas near shallow water preferred by the listed birds are being replaced by narrow river channels and expanding woodlands. Conflicts over the protection of federally listed species and water management in the Platte River Basin have existed for more than 25 years. In recent years, the Fish and Wildlife Service of the U.S. Department of the Interior issued a series of opinions requiring that new water depletions would have to be balanced by mitigation measures, and a lawsuit forced the designation of "critical habitat" for the piping plover. These and other controversies prompted the Department of the Interior and the Governance Committee of the Platte River Endangered Species Partnership to request that the Research Council examine whether the current designations of "critical habitat" for the whooping crane and piping plover are supported by existing science. The Research Council was also asked to assess whether current habitat conditions are affecting the survival of listed species or limiting their chances of recovery, and to examine the scientific basis for the department's instream-flow recommendations, habitat-suitability guidelines, and other decisions. The report concludes that in most instances habitat conditions are indeed affecting the likelihood of species survival and recovery. For example, the central Platte habitat is important to whooping cranes because many, if not all, stop there during migration at some point in their lives; about 7 percent of the total population stops there in any one year. The report also notes that if whooping crane deaths -- which occur primarily during migration -- were to increase by only 3 percent, the general population would probably become unstable. Whooping cranes are the rarest species of crane in the world; only about 185 wild birds remain. If habitat conditions decline substantially, recovery of the whooping crane could be slowed or reversed, the report adds. Deterioration and loss of habitat in the central Platte is contributing to the continuing drop in numbers of piping plovers and interior least terns, the report says. Human activities and increased attacks by predators on nests are also key factors in the birds' decline. Almost no piping plovers live along the central Platte anymore, but because the area did provide a suitable habitat for reproduction until a few years ago, it should still be considered a critical habitat, according to the committee. Although the population of interior least terns on the central Platte River continues to decline, the birds are nesting on the lower Platte River, the report notes. Current habitat conditions on the lower Platte River are not adversely affecting pallid sturgeon, the report says; the area still retains the characteristics preferred by the species. However, it is appropriate to consider the lower Platte critical to the survival and recovery of the fish because of their low numbers in other parts of the Platte and in the Missouri River, where dams have depleted suitable habitat. The report committee cited many gaps in knowledge, and urged that a systematic inventory of all actions contributing to the decline of the listed species be undertaken. This knowledge would help environmental interests, water users, and government officials reach a cooperative agreement on how to manage water and promote the species' recovery. An approach to decision-making that considers multiple species and habitats outside the Platte River Basin should replace the current approach, which has focused on single species and specific locales. The dynamics and connections between surface water and groundwater need to be better understood, as do the effects of the currently required flow on the river's shape and vegetation. The cost-effectiveness of conservation actions also should be considered, as permitted under the Endangered Species Act, and the burden of these measures should be borne equitably among water users. The report was sponsored by the U.S. Department of the Interior. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides science and technology advice under a congressional charter. A committee roster follows. Copies of Endangered and Threatened Species of the Platte River will be available in June from the National Academies Press; tel. (202) 334-3313 or 1-800-624-6242 or on the Internet at http://www.nap.edu. Reporters may obtain a copy from the Office of News and Public Information (contacts listed above). National Research Council Division on Earth and Life Studies Board on Environmental Studies and Toxicology and Water Science and Technology Board Committee on Endangered and Threatened Species in the Platte River Basin William L. Graf, Ph.D. (chair) Educational Foundation University Professor and Professor of Geography University of South Carolina Columbia John "Jeb" Barzen, M.S. Director of Field Ecology International Crane Foundation Baraboo, Wis. Francesca Cuthbert, Ph.D. Professor Department of Fisheries and Wildlife, and Co-Director, Conservation Biology Graduate Program University of Minnesota St. Paul Holly Doremus, Ph.D., J.D. Professor of Law University of California Davis Lisa M. Butler Harrington, Ph.D. Associate Professor of Geography Kansas State University Manhattan Edwin E. Herricks, Ph.D. Professor of Environmental Biology Environmental Engineering and Science Program Department of Civil and Environmental Engineering University of Illinois Urbana Katharine L. Jacobs, M.L.A. Associate Professor of Soil, Water, and Environmental Science University of Arizona Tucson W. Carter Johnson, Ph.D. Professor of Ecology South Dakota State University Brookings Frank Lupi, Ph.D. Associate Professor of Environmental and Natural Resource Economics Departments of Agricultural Economics and Fisheries and Wildlife Michigan State University East Lansing Dennis D. Murphy, Ph.D. Research Professor Biology Department, and Director Graduate Program in Ecology, Evolution, and Conservation Biology University of Nevada Reno Richard N. Palmer, Ph.D. Professor Department of Civil and Environmental Engineering University of Washington Seattle Edward J. Peters, Ph.D. Professor of Fisheries School of Natural Resource Sciences University of Nebraska Lincoln Hsieh Wen Shen, Ph.D.* Professor Emeritus Civil and Environmental Engineering University of California Berkeley James Anthony Thompson, B.S. Farmer Willow Lake Farm Windom, Minn. RESEARCH COUNCIL STAFF Suzanne Van Drunick, Ph.D. Study Director ^* Member, National Academy of Engineering