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.
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A report on genetic affinities and relatedness of Agassiz’s desert tortoises (Gopherus agassizii) at opposite ends of the Coachella Valley in California A report on genetic affinities and relatedness of Agassiz’s desert tortoises (Gopherus agassizii) at opposite ends of the Coachella Valley in California
This report summarizes the results for mtDNA and STR genotyping of 41 desert tortoise (Gopherus agassizii) DNA samples from opposite sides of the Coachella Valley: one sample from the west side at the Mesa wind energy facility in the Whitewater Hills and the other from the mouth of Cottonwood Canyon in Joshua Tree National Park, both within the boundaries of the Coachella Valley Multiple...
Authors
Jeffrey E. Lovich, Taylor Edwards, Brian Kreiser, Shellie R. Puffer, Mickey Agha
Food-web structure in canyon and slope-associated fauna revealed by stable isotopes Food-web structure in canyon and slope-associated fauna revealed by stable isotopes
Food webs and associated trophic linkages among organisms are central themes in ecology that provide insight into the structure and function of ecosystems. In the deep sea, food webs rely on particulate flux raining from surface waters for energy (Klages et al. 2003), except for chemosynthetic communities, which rely on in situ production via chemosynthesis (Van Dover 2007). In general...
Authors
Amanda W. J. Demopoulos, Jennifer P. McClain-Counts, Steve W. Ross, Sandra Brooke, Michael Rhode
Climate change and collapsing thermal niches of Mexican endemic reptiles Climate change and collapsing thermal niches of Mexican endemic reptiles
Recent climate change should result in expansion of species to northern or high elevation range margins, and contraction at southern and low elevation margins due to extinction. Climate models predict dramatic extinctions and distributional shifts in the next century, but there are few ground-truths of these dire forecasts leading to uncertainty in predicting extinctions due to climate...
Authors
Barry Sinervo, Donald B. Miles, Rafael A. Lara Resendiz, Jeffrey E. Lovich, Joshua R. Ennen, Johannes Muller, Robert D. Cooper, Philip C. Rosen, Joseph A. E. Stewart, Juan Carlos Santos, Jack W. Sites, Paul Gibbons, Eric Goode, L. Scott Hillard, Luke Welton, Mickey Agha, Gabriel Caetano, Mercy Vaughn, Cristina Melendez Torres, Hector Gadsden, Gamaliel Castenada Gaytan, Patricia Galina-Tessaro, Fernando I. Valle Jimenez, Jorge H. Valdez-Villavicencio, Norberto Martinez Mendez, Guillermo Woolrich Pina, Victor Luja Molina, Anibal Diaz de la Vega Perez, Diego M. Arenas Moreno, Saul Dominguez Guerrero, Natalia Fierro, Scott Butterfield, Michael Westpha, Raymond B. Huey, William Mautz, Víctor Sánchez-Cordero, Fausto R. Mendez de la Cruz
Herring Disease Program – Herring Disease Program II Herring Disease Program – Herring Disease Program II
No abstract available.
Authors
Paul Hershberger, Maureen K. Purcell
Adaptive harvest management for the Svalbard population of pink-footed geese (Anser brachyrhynchus) Adaptive harvest management for the Svalbard population of pink-footed geese (Anser brachyrhynchus)
This document describes progress to date on the development of an adaptive harvest-management strategy for maintaining the Svalbard population of pink-footed geese (Anser brachyrhynchus) near their target level (60,000) by providing for sustainable harvests in Norway and Denmark. Specifically, this report provides an assessment of the most recent monitoring information and its...
Yellowstone grizzly bear investigations — Annual report of the Interagency Grizzly Bear Study Team 2016 Yellowstone grizzly bear investigations — Annual report of the Interagency Grizzly Bear Study Team 2016
This Annual Report summarizes results of grizzly bear (Ursus arctos) monitoring and research conducted in the Greater Yellowstone Ecosystem (GYE) by the Interagency Grizzly Bear Study Team (IGBST) during 2016. The report also contains a summary of grizzly bear management actions to address conflict situations.
A simulation method for combining hydrodynamic data and acoustic tag tracks to predict the entrainment of juvenile salmonids onto the Yolo Bypass under future engineering scenarios A simulation method for combining hydrodynamic data and acoustic tag tracks to predict the entrainment of juvenile salmonids onto the Yolo Bypass under future engineering scenarios
During water year 2016 the U.S. Geological Survey California Water Science Center (USGS) collaborated with the California Department of Water Resources (DWR) to conduct a joint hydrodynamic and fisheries study to acquire data that could be used to evaluate the effects of proposed modifications to the Fremont Weir on outmigrating juvenile Chinook salmon. During this study the USGS...
Authors
Aaron R. Blake, Paul Stumpner, Jon R. Burau
A water-budget analysis of Medina and Diversion Lakes and the Medina/Diversion Lake system, with estimated recharge to Edwards aquifer, San Antonio area, Texas A water-budget analysis of Medina and Diversion Lakes and the Medina/Diversion Lake system, with estimated recharge to Edwards aquifer, San Antonio area, Texas
In January 2001, the U.S. Geological Survey—in cooperation with the Edwards Aquifer Authority—began a study to refine and, if possible, extend previously derived (1995–96) relations between the stage in Medina Lake and recharge to the Edwards aquifer to include the effects of reservoir stages below 1,018 feet and greater than 1,046 feet above National Geodetic Vertical Datum of 1929. The...
Authors
Richard N. Slattery, Lisa D. Miller
Acoustic assessment of pelagic planktivores, 2016 Acoustic assessment of pelagic planktivores, 2016
Alewife (Alosa pseudoharengus) and Rainbow Smelt (Osmerus mordax) are the most abundant pelagic planktivores in Lake Ontario (Weidel et al 2017), and the most important prey for salmon and trout, making up greater than 90% of the diet of the top predator, Chinook salmon (Lantry 2001, Brandt 1986), and supporting a multimillion dollar sportfishery. Alewife are also important prey for warm...
Authors
Jeremy P. Holden, Michael J. Connerton, Brian Weidel
Application of paleoflood surveys for the southern Black Hills of South Dakota Application of paleoflood surveys for the southern Black Hills of South Dakota
Flood-frequency analyses for the Black Hills area have especially large uncertainties and are especially important for planning purposes because of a history of extremely large and damaging floods, such as the extreme floods of June 9–10, 1972. Geology, topography, and climatology are additional complicating factors for flood-frequency characterization for the area. Two previous...
Authors
Daniel G. Driscoll
Conflict minerals from the Democratic Republic of the Congo—Tin processing plants, a critical part of the tin supply chain Conflict minerals from the Democratic Republic of the Congo—Tin processing plants, a critical part of the tin supply chain
Summary The U.S. Geological Survey (USGS) analyzes mineral and metal supply chains to identify and describe major components of material flows from ore extraction, through intermediate forms, to a final product. Supply chain analyses may be used (1) to identify risks to the United States associated with the supply of critical and strategic minerals and metals and (2) to provide greater...
Authors
Charles Anderson
Ecological risk assessment of Grass Carp (Ctenopharyngodon idella) for the Great Lakes Basin Ecological risk assessment of Grass Carp (Ctenopharyngodon idella) for the Great Lakes Basin
Grass Carp (Ctenopharyngodon idella) is an herbivorous, freshwater fish that was first introduced in the United States in the early 1960s for use in biological control of aquatic vegetation. It has since escaped and dispersed through the Mississippi River basin towards the Great Lakes. To characterize the risk of Grass Carp to the Great Lakes basin, a binational ecological risk...
Authors
Cynthia S. Kolar, Becky Cudmore