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: 83829
Status and trends in the Lake Superior fish community, 2021
The Lake Superior nearshore fish community was sampled in May-June 2021 with daytime bottom trawl tows at 45 stations located in USA waters. The 45 locations sampled were long-term monitoring sites that had been annually sampled since 1978. All comparisons to 2021 results were limited to past collections from USA waters, as compared to previous years, where comparisons included USA and Canadian si
Authors
Mark Vinson, Daniel Yule, Lori M. Evrard, Owen T. Gorman, Sydney B Phillips
Status and trends in the Lake Superior fish community, 2020
The Lake Superior fish community within Management Unit WI-2 was sampled in July 2020 with daytime bottom trawls at 11 nearshore stations. The 11 locations sampled were long-term monitoring sites that had been annually sampled since 1974. In 2020, the number of species collected at each site ranged from 0 to 13, with a mean of 6.3 and median of six. All comparisons to 2020 results were limited to
Authors
Mark Vinson, Lori M. Evrard, Owen Gorman, Daniel Yule
Effect of repeated fire on annual brome invasion at Badlands National Park
Prescribed fire is used to combat exotic plant species in mixed-grass prairie of Northern Great Plains parks. However, prescribed fires rarely occur at a frequency likely to maintain any gains against exotic species. The unusual circumstance of experimental plots being burned twice in 2 years provides a unique opportunity to investigate the effect of more frequent fire on invasive annual brome gra
Authors
Amy Symstad
Characterization of subsurface conditions and recharge at the irrigated four-plex baseball field, Fort Irwin National Training Center, California, 2018–20
The U.S. Geological Survey performed subsurface and geophysical site characterization of the irrigated four-plex baseball field in the Langford Valley–Irwin Groundwater Subbasin, as part of a research study in cooperation with the U.S. Environmental Protection Agency, the Agricultural Research Service, and the Fort Irwin National Training Center, California. To help meet future demands, the Fort I
Authors
Jill N. Densmore, Meghan C. Dick, Krishangi D. Groover, Christopher P. Ely, Anthony A. Brown
Range-wide population trend analysis for greater sage-grouse (Centrocercus urophasianus)—Updated 1960–2021
Greater sage-grouse (Centrocercus urophasianus) are at the center of state and national land use policies largely because of their unique life-history traits as an ecological indicator for health of sagebrush ecosystems. This updated population trend analysis provides state and federal land and wildlife managers with best-available science to help guide current management and conservation plans ai
Authors
Peter S. Coates, Brian G. Prochazka, Cameron L. Aldridge, Michael S. O'Donnell, David R. Edmunds, Adrian P. Monroe, Steve E. Hanser, Lief A. Wiechman, Michael P. Chenaille
Bureau of Reclamation: Visitor satisfaction survey instructions
The purpose of the Bureau of Reclamation (BOR) Visitor Satisfaction Survey is to measure visitors’ opinions about BOR facilities, services, and recreational opportunities. This effort helps BOR meet requirements of the Government Performance and Results Act of 1993 (GPRA) and other BOR and Department of the Interior (DOI) strategic planning efforts. This survey manual provides the detailed methods
Authors
Emily J. Wilkins, Nicholas Cole, Rudy Schuster
Discerning behavioral patterns of sea turtles in the Gulf of Mexico to inform management decisions
The protection of all sea turtles globally is a high priority, and research projects on these imperiled species are focused on those that are likely to result in improvements in monitoring and management for population recovery. Determining distribution, seasonal movements, vital rates and habitat use for all life-stages of sea turtles has been identified by the US Fish and Wildlife Service (USFWS
Authors
Kristen Hart, Margaret Lamont
Red knot stopover population size and migration ecology at Delaware Bay, USA, 2022
Red Knots (Calidris canutus rufa) stop at Delaware Bay on the mid-Atlantic coast of North America during northward migration to feed on eggs of horseshoe crabs (Limulus polyphemus). In the late 1990s and early 2000s, the number of Red Knots found at Delaware Bay declined from ~50,000 to ~13,000. Horseshoe crabs have been harvested for use as bait in eel (Anguilla rostrata) and whelk (Busycon) fish
Authors
James E. Lyons
Continuous water-quality and suspended-sediment transport monitoring in San Francisco Bay, California, water years 2020–21
The U.S. Geological Survey (USGS) has continuously monitored real-time water quality and suspended-sediment transport in San Francisco Bay (the Bay) since 1989 as part of a multi-agency effort (see “Acknowledgments” section) to address estuary management, water supply, and ecological concerns. The San Francisco Bay area is home to millions of people and biologically diverse marine and terrestrial
Authors
Danielle L. Palm, Darin C. Einhell, Selina M. Davila Olivera
Hydrologic effects of leakage from the Catskill Aqueduct on the bedrock-aquifer system near High Falls, New York, November 2019–January 2020
Historical observations by the New York City Department of Environmental Protection (NYCDEP) indicate that the Rondout pressure tunnel has been leaking in the vicinity of the hamlet of High Falls, New York. In the 74 days from November 11, 2019, to January 23, 2020, NYCDEP shut down and partially dewatered the pressure tunnel for inspection and repairs. On November 5–7, 2019 (during normal tunnel
Authors
Anthony Chu, Michael L. Noll, William D. Capurso
Field techniques for the determination of algal pigment fluorescence in environmental waters—Principles and guidelines for instrument and sensor selection, operation, quality assurance, and data reporting
The use of algal fluorometers by the U.S. Geological Survey (USGS) has become increasingly common. The basic principles of algal fluorescence, instrument calibration, interferences, data quantification, data interpretation, and quality control are given in Hambrook Berkman and Canova (2007). Much of the guidance given for instrument maintenance, data storage, and quality assurance in Wagner and ot
Authors
Guy M. Foster, Jennifer L. Graham, Brian A. Bergamaschi, Kurt D. Carpenter, Bryan D. Downing, Brian A. Pellerin, Stewart A. Rounds, John Franco Saraceno
Technical note—Performance evaluation of the PhytoFind, an in-place phytoplankton classification tool
In 2019, the U.S. Geological Survey evaluated the performance of the Turner Designs, Inc. PhytoFind, an in-place phytoplankton classification tool. The sensor was tested with sample blanks, monoculture and mixed phytoplankton cultures, and turbidity challenges in a laboratory, and was tested on a 120-mile survey of the Caloosahatchee and St. Lucie Rivers in Florida, including Lake Okeechobee. Resu
Authors
Brett D. Johnston, Jennifer L. Graham, Guy M. Foster, Bryan D. Downing