Publications

Passage and transit time of adult upstream-migrant American shad Alosa sapidissima and blueback herring A. aestivalis were investigated in standard Denil and Alaska steeppass fishways with variable slope and headpond under semicontrolled conditions. Percent of American shad passed per unit time (percent passage) increased with temperature, while time required to ascend from the fishway...

Trail impact assessment and monitoring (IA&M) programs have been growing in importance and application in recreation resource management at protected areas. Census-based and sampling-based approaches have been developed in such programs, with systematic point sampling being the most common survey design. This paper examines the influence of sampling interval on the accuracy of estimates...

Overabundant populations of white-tailed deer (Odocoileus virginianus) are becoming common in the eastern United States. Faced with burgeoning deer populations in eastern parks, the National Park Service (NPS) formulated policy based on its long experience with ungulate management in western parks. That the NPS failed to find a management solution acceptable to its many constituencies...

Salmonid whirling disease is caused by Myxobolus cerebralis, a metazoan parasite with a two host life cycle involving salmonid fish a an aquatic oligochaete, Tubifex tubifex (Wolf, Markiw and Hiltunen, 1986). Whirling disease has been reported in 22 U.S. states with the greatest losses occurring in the salmonid fisheries of western and Midwestern states. Although whirling disease is...

Whirling disease is caused by Myxobolus cerebralis and requires an intermediate oligochaete host identified as Tubifex tubifex (Wolf, Markiw, and Hiltunen, 1986). M. cerebralis spores ingested by the tubifex worms develop into triactinomyxons (tams) that are eventually released into the water column to infect salmonid fish. There may be many environmental parameters, biotic or abiotic...

No abstract available.

Eastern hemlock (Tsuga canadensis) is in decline throughout its range in the eastern US due to infestation by an exotic insect pest, the hemlock woolly adelgid (Adelges tsugae). In Shenandoah National Park, the hemlock woolly adelgid (HWA) rapidly killed many stands of hemlock after first appearing in the late-1980’s, while having only minor impact in other stands. At present, few...

Aerial gamma-ray spectrometric and magnetic survey maps are valuable aids for geologic mapping where rocks are poorly exposed in south-central Virginia and northernmost North Carolina. Broad low areas on the potassium and thorium gamma-ray survey maps distinguish the Carolina, Spring Hope, and Roanoke Rapids terranes from more highly radiogenic areas of the Raleigh and Triplet terranes...

We examined 4,848 regurgitated digestive pellets of double-crested cormorants (Phalacrocorax auritus) over a 6-year period (1992–97) to estimate annual predation on sport and other fishes in the eastern basin of Lake Ontario. We found more than 51,000 fish of 28 species. Using a model that incorporates annual colony nest counts; fledgling production rates; adult, immature, and young-of...

No abstract available.

Early growth of Roseate Tern (Sterna dougallii) chicks is a strong predictor of chick survival and hence of productivity. We developed discriminant functions to predict chick survival from body-masses measured during the first 3 days of life. Productivity is estimated by assuming that almost all A-chicks (first-hatched in each brood) survive to fledging, and using the discriminant...

As part of the U.S. Department of Defense Base Realignment and Closure process, the former Fort Benjamin Harrison in Marion County, Indiana (called 'Fort Harrison' in this fact sheet), was placed on the Base Closure List in 1991. Property disposal and reuse activities began when Fort Harrison was decommissioned in 1995; work continues through 1999. Fort Harrison was located on...