Reports
Science Quality and Integrity
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 82,000 reports authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
Filter Total Items: 84725
Assessment of microscopic pathology in fishes collected at sites impacted by wood tar in Pennsylvania Assessment of microscopic pathology in fishes collected at sites impacted by wood tar in Pennsylvania
In an effort to determine whether fish populations in an area affected by wood tar waste exhibited health effects, fish were collected and analyzed with histopathology. Multiple species, including Mottled Sculpin (Cottus bairdii), Creek Chub (Semotilus atromaculatus), White Sucker (Catostumus commersonii), Redside Dace (Clinostomus elongatus), Common Shiner (Luxilus cornutus), and...
Authors
Heather L. Walsh, Vicki S. Blazer, Patricia M. Mazik, Adam J. Sperry, Diana Pavlick
Human dimensions considerations in wildlife disease management Human dimensions considerations in wildlife disease management
In 1943, Aldo Leopold observed that the real problem of wildlife management is not how to handle wildlife, but how to manage humans. As with any other aspect of wildlife management, social sciences can improve understanding the human dimensions of wildlife disease management (WDM). Human activities have accelerated the emergence of wildlife diseases, and human concerns about the...
Authors
Kirsten Leong, Daniel J. Decker
Trends in streamflow and precipitation for selected sites in the Elkhorn River Basin and in streamflow in the Salt Creek and Platte River Basins, Nebraska, 1961–2011 Trends in streamflow and precipitation for selected sites in the Elkhorn River Basin and in streamflow in the Salt Creek and Platte River Basins, Nebraska, 1961–2011
To better understand the streamflow trends at the streamgages in the Elkhorn River Basin in Nebraska, the U.S. Geological Survey (USGS) in cooperation with the Lower Elkhorn Natural Resources District further investigated streamflow trends at the eight streamgages on the Elkhorn River, Salt Creek, and the Lower Platte River that indicated a positive trend in streamflow characteristics...
Authors
Benjamin J. Dietsch, Kellan R. Strauch
The effects of management practices on grassland birds—Merlin (Falco columbarius) The effects of management practices on grassland birds—Merlin (Falco columbarius)
The key to Merlin (Falco columbarius) management is maintaining an interspersion of groves of deciduous or coniferous trees for nesting and open grasslands for hunting. Merlins do not build their own nests but rather use former nests of other bird species, including those of corvids (crows, ravens, and magpies) and accipitrids (hawks). In recent decades, Merlins have established breeding
Authors
Paul M. Konrad, Jill A. Shaffer, Lawrence D. Igl
The effects of management practices on grassland birds—Sprague’s Pipit (Anthus spragueii) The effects of management practices on grassland birds—Sprague’s Pipit (Anthus spragueii)
Keys to Sprague’s Pipit (Anthus spragueii) management include providing suitable grassland habitat, especially native prairie, with intermediate vegetation height and low visual obstruction, and controlling succession therein. Sprague’s Pipits have been reported to use habitats with no more than 49 centimeters (cm) average vegetation height, 4–14 cm visual obstruction reading, 15–53...
Authors
Jill A. Shaffer, Lawrence D. Igl, Douglas H. Johnson, Marriah L. Sondreal, Christopher M. Goldade, Melvin P. Nenneman, Travis L. Wooten, Jason P. Thiele, Betty R. Euliss
Juvenile Lost River and shortnose sucker year-class formation, survival, and growth in Upper Klamath Lake, Oregon and Clear Lake Reservoir, California—2017 Monitoring Report Juvenile Lost River and shortnose sucker year-class formation, survival, and growth in Upper Klamath Lake, Oregon and Clear Lake Reservoir, California—2017 Monitoring Report
Executive Summary Populations of federally endangered Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Upper Klamath Lake, Oregon, and Clear Lake Reservoir (hereinafter referred to as Clear Lake; fig. 1), California, are experiencing long-term declines in abundance. Upper Klamath Lake populations are decreasing because juvenile suckers are not surviving...
Authors
Ryan J. Bart, Summer M. Burdick, Marshal S. Hoy, Carl O. Ostberg
Evaluating dewatering approaches to protect larval Pacific lamprey Evaluating dewatering approaches to protect larval Pacific lamprey
Executive Summary Larval Pacific lamprey live for several years burrowed in nearshore sediments where they filter feed on detritus and organic matter. Dewatering of larval habitat can occur as a result of flow-management practices, construction projects, or seasonal closures of irrigation diversions. Effective management of dewatering events requires guidance on approaches to protect...
Authors
Theresa L. Liedtke, Lisa K. Weiland, Joseph J. Skalicky, Ann E. Gray
Status and trends of pelagic and benthic prey fish populations in Lake Michigan, 2019 Status and trends of pelagic and benthic prey fish populations in Lake Michigan, 2019
Lakewide acoustic (AT) and bottom trawl (BT) surveys are conducted annually to generate indices of pelagic and benthic prey fish densities in Lake Michigan. The BT survey has been conducted each fall since 1973 using 12-m trawls at depths ranging from 9 to 110 m and include 70 fixed locations distributed across seven transects; this survey estimates densities of seven prey fish species...
Authors
David Bunnell, David Warner, Charles P. Madenjian, Ben Turschak, Patricia Dieter, Tim Desorcie
Geologic map of the Paeroa Fault block and surrounding area, Taupo Volcanic Zone, New Zealand Geologic map of the Paeroa Fault block and surrounding area, Taupo Volcanic Zone, New Zealand
The Taupo Volcanic Zone (TVZ), New Zealand, is the most productive area of explosive silicic volcanism in the world. Faulted early and middle Pleistocene volcanic products are generally concealed beneath voluminous, generally unfaulted, younger volcanic products. An exception is the southeast margin of the TVZ where the two parallel, northeast-trending Paeroa and Te Weta Fault blocks...
Authors
Drew T. Downs, Graham S. Leonard, Colin J. N. Wilson, Julie V Rowland
Water resources of Union Parish, Louisiana Water resources of Union Parish, Louisiana
Information concerning the availability, use, and quality of water in Union Parish, Louisiana, is critical for proper water-supply management. The purpose of this fact sheet is to present information that can be used by water managers, parish residents, and others for stewardship of this vital resource. In 2014, about 4.88 million gallons per day (Mgal/d) of water were withdrawn in Union...
Authors
Angela L. Robinson
Geochemical and mineralogical study of the Red Mountain porphyry copper-molybdenum deposit and vicinity, Santa Cruz County, Arizona Geochemical and mineralogical study of the Red Mountain porphyry copper-molybdenum deposit and vicinity, Santa Cruz County, Arizona
The Red Mountain porphyry copper-molybdenum deposit (Cu-Mo deposit or PCD) is located in the northern part of the Patagonia Mountains, Santa Cruz County, Arizona. Extensive core drilling has delineated a large, deep-seated, structurally intact mineral system that extends from the present surface to depths of more than 1,765 meters. This system is hosted in a thick complex of...
Authors
Maurice Chaffee
A historical look at changing water quality in the Delaware River basin A historical look at changing water quality in the Delaware River basin
In 2019 the U.S. Geological Survey (USGS) launched a pilot regional Integrated Water Availability Assessment (IWAA) in the Delaware River Basin (fig. 1). IWAA is intended to explore, test, and refine systems and processes for assessing water availability for human and ecological uses and understanding their underlying controls. Water quality plays an important role in supporting...
Authors
Jennifer C. Murphy, Megan E. Shoda