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Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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At least 145 records · Page 8Linked to original sources
USGS2004

Distribution and relative abundance of fishes in littoral areas of Chief Joseph Reservoir, Columbia River

We surveyed fish assemblages in littoral areas of Chief Joseph Reservoir of the upper Columbia River to aid in understanding this ecosystem. Fish distributions and abundances were examined during April-July 1999 in relation to environmental conditions in the reservoir. We also compared the fish assemblages in Chief Joseph reservoir in 1999 to a past study conducted during 1974-1975, and to assemblages in other areas of the Columbia River. During 67 hr of electrofishing and 78 beach seine hauls in Chief Joseph Reservoir, 7460 fishes representing 8 families were collected. The majority of the catch was native – northern pikeminnow; redside shiners; longnose, bridgelip, and largescale suckers; and sculpins. The most abundant introduced species was walleye, and one species, rainbow trout, was mostly of net-pen origin. Larger sizes of suckers and northern pikeminnow were most abundant in the upper reservoir, likely due to upstream spawning migrations. The lower reservoir contained greater abundances of smaller fishes, and this area had lower flows, smaller substrates, and more complex shorelines that offered these fishes refugia. Only adult suckers displayed significant differences in abundances related to substrate. The relative abundances of species appeared to have changed since the 1970s, when the dominant fishes were northern pikeminnow, peamouth, largescale suckers, and walleye. Fish assemblage differences between Chief Joseph Reservoir and lower Columbia River reservoirs were also evident due to the morphology of the reservoir, its more northerly location, and the lack of fish passage facilities at Chief Joseph Dam. Our study is one of the few descriptions of fishes in the upper Columbia Rivers.

Washington↗
USGS1995

Influence of temperature on incubation rates of coho salmon ( Oncorhynchus kisutch ) from ten Washington populations

Coho salmon from 10 Washington populations were incubated under controlled conditions to determine the levels of variation in time to hatch among populations and families within populations. The average incubation rate was somewhat slower than that estimated from a quantitative model derived from British Columbia populations, and was slightly faster than that predicted by a Washington model. Significant variation in incubation rated among the Washington populations was detected, consistent with results from other studies. Data of first hatching of families within populations ranged more than two weeks at 6°C. Within families, the first and last individuals to hatch ranged over 1-3 weeks. The variation within populations and families will contribute to the variation in emergence date of fry, which will affect their growth and survival.

Washington↗
USGS1987

Roosevelt elk density in old-growth forests of Olympic National Park

We explored the feasibility of censusing Roosevelt elk from a helicopter in the dense old growth forests of Olympic National Park. WA. Mean observed densities ranged from 8.0-11.6 elk/km 2 , with coefficients of variation averaging 19.9 percent. A provisional sightability factor of 74 percent suggested that actual mean densities ranged from 10.8-16.0 elk/km 2 . We conclude that estimates of elk density probably could be refined, but not without a cost and level of disturbance in the park that seem unwarranted at present. The effort required to conduct the 18 counts made during 1985-86 was substantial. For almost every successful count an unsuccessful attempt was made. These included aborting five flights when counting conditions turned sour. Actual counting time for the successful flights was 15.7 and 16.2 hours in 1985 and 1986, respectively. Additional flight time for traveling to and from the census zones, refueling, and aborted attempts added 12.2 and 10.8 hours for the respective years

Washington↗
USGS1993

Roosevelt elk selection of temperate rain forest seral stages in western Washington

We studied habitat selection by Roosevelt elk ( Cervus elaphus roosevelti ) in a temperate rain forest in the lower Queets River Valley of the western Olympic Peninsula, Washington from June 1986-July 1987. Elk annual home ranges included predominantly unlogged forests protected within Olympic National Park and logged, regenerating forests adjacent to the park. Radio-collared elk selected valley floors during all seasons except winter, when elk frequently used an adjoining plateau 60 m above the floodplain. In winder, radio-collared elk selected 6-15 year-old clearcuts, which were available on the plateau. Elk selected mature deciduous forests of the valley floor during spring, summer, and autumn, and generally they selected old-age Sitka spruce forests during autumn and winter. Young clearcuts (1-5 years old) and even-aged, regenerating stands (16-150 years old) generally were avoided during all seasons. Management practices that retain preferred habitat of elk, such as deciduous forests, 6-15 yr-old coniferous stands, and old-age coniferous bottomland forests will benefit elk, particularly on elk ranges managed for short-rotation, even-aged stands. Silvicultural alternatives to typical even-aged stand management, such as uneven-aged management and commercial thinning, should also be considered for improving and maintaining interspersion of forage and cover.

Washington↗
USGS2002

Terrestrial and stream amphibians across clearcut-forest interfaces in the Siskiyou Mountains, Oregon

Timber harvest in the Pacific Northwest has resulted in a highly fragmented landscape. but there is no information on responses of amphibians to forest edges for this region. We investigated abundance of terrestrial and stream-dwelling amphibians on the interface of recent clearcuts and mature forest in the Siskiyou Mountains, Oregon, in summer and fall of 1998. We assessed relative abundance of terrestrial -amphibians on four clearcut forest transects with a combination of pitfall trapping and manual searches. Ensantinas and Del Norte salamanders, the most frequently recorded species, were found on all four sites. While we commonly captured ensantinas using both techniques, we caught most Del Norte salamanders during manual searches. For both species we found no differences in abundance associated with distance to forest edge. Lack of differences in salamander abundance among clearcut and adjacent forests may be related lo large amounts of small woody debris that remained in the clearcuts. The abundance of larvae of tailed frogs and Pacific giant salamanders in five headwater streams was markedly lower in clearcuts than in downstream mature forest stands. No obvious differences existed for stream habitat variables across transects. but abundance of metamorphosed individuals and recruitment may be reduced in clearcut areas due lo hotter and drier conditions during

Oregon↗
USGS2013

Executive summary: Climate change in the northwest: Implications for our landscapes, waters, and communities

Climate Change in the Northwest: Implications for Our Landscapes, Waters, and Communities is aimed at assessing the state of knowledge about key climate impacts and consequences to various sectors and communities in the northwest United States. It draws on a wealth of peer-reviewed literature, earlier state-level assessment reports conducted for Washington (2009) and Oregon (2010), as well as a risk-framing workshop. As an assessment, it aims to be representative (though not exhaustive) of the key climate change issues as reflected in the growing body of Northwest climate change science, impacts, and adaptation literature now available. This report will serve as an updated resource for scientists, stakeholders, decision makers, students, and community members interested in understanding and preparing for climate change impacts on Oregon, Washington, and Idaho. This more detailed, foundational report is intended to support the key findings presented in the Northwest chapter of the Third National Climate Assessment.

Idaho;Oregon;Washington↗
USGS2018

U.S. Department of the Interior Climate Science Centers and U.S. Geological Survey National Climate Change and Wildlife Science Center—Annual report for 2017

Introduction The year 2017 was a year of review and renewal for the Department of the Interior (DOI) Climate Science Centers (CSCs) and the U.S. Geological Survey (USGS) National Climate Change and Wildlife Science Center (NCCWSC). The Southeast, Northwest, Alaska, Southwest, and North Central CSCs’ 5-year summary review reports were released in 2017 and contain the findings of the external review teams led by the Cornell University Human Dimensions Research Unit in conjunction with the American Fisheries Society. The reports for the Pacific Islands, South Central, and Northeast CSCs are planned for release in 2018. The reviews provide an opportunity to evaluate aspects of the cooperative agreement, such as the effectiveness of the CSC in meeting project goals and assessment of the level of scientific contribution and achievement. These reviews serve as a way for the CSCs and NCCWSC to look for ways to recognize and enhance our network’s strengths and identify areas for improvement. The reviews were followed by the CSC recompetition, which led to new hosting agreements at the Northwest, Alaska, and Southeast CSCs. Learn more about the excellent science and activities conducted by the network centers in the 2017 annual report.

Open-File Report↗
USGS2021

Scale growth rates and scale circulus deposition rates of marine-stage Atlantic salmon Salmo salar raised under semi-natural conditions

Scale circuli yield valuable information about the life history, age, and growth of a fish. However, because circuli formation is influenced by somatic growth, the rate at which circuli are formed and the factors influencing these rates must be taken into account for the given life stage of the study species. Scales were collected from Atlantic salmon raised in marine net pens off of the coast of Maine in order to characterize the formation of scale circuli and the growth of scales during the ocean phase, and to relate circulus deposition and scale growth rate to water temperature. Fish were sampled 13 times over a period of 25 months. Neither circulus deposition rate nor growth rate were constant through time and the same trend held when circulus deposition and growth were related to thermal experience. Both rates decreased over the course of the study, presumably related to the fish reaching sexual maturity. The results of this study indicate that the pattern of circulus deposition and scale growth of Atlantic salmon vary greatly during the early marine phase, and this dynamic should be taken into account when assessing growth, especially over short time periods.

Newfoundland↗
USGS2000

Origin of Amazon mudbanks along the northeastern coast of South America

Seismic profiles, sediment cores, and water column measurements were collected along the northeastern coast of Brazil to examine the origin of mudbanks in the Amazon coastal mud belt. These 10-60-km-long, shore-attached features previously had been observed to migrate along the 1200 km coast of the Guianas in response to wave forcing. CHIRP (3.5 kHz) seismic profiles of the shoreface and inner shelf located two mudbanks updrift of the previous eastern limit in French Guiana. 210Pb geochronology shows that these two banks are migrating to the northwest over a relict mud surface in 5-20 m water depth. The mudbanks are 3-4 m thick and are translating over a modern shoreface mud wedge deposited by previous mudbank passage in < 5 m water depth. Initial mudbank development is taking place on the intertidal and shallow subtidal mudflats at Cabo Cassipore, associated with an alongshore-accreting clinoform feature. Sediment trapping in this area is controlled by the nearshore presence of strong water column stratification produced by the enormous Amazon freshwater discharge on the shelf and by proximity to the Cassipore River estuary. Seasonal and decadal periods of sediment supply and starvation in this area likely are controlled by variations in northwest trade wind intensity. (C) 2000 Elsevier Science B.V.

Marine Geology↗
USGS2017

A path to actionable climate science: Perspectives from the field

The U.S. Department of the Interior Climate Science Centers (CSCs) work with natural and cultural resource managers and scientists to gather information and build tools needed to help fish, wildlife, and ecosystems adapt to the impacts of climate change. The CSCs prioritize the delivery of actionable science products (e.g., synthesized scientific information, maps, decision support tools, etc.) that are focused on key management priorities and co-produced by teams of scientists and managers. In the specific case of the Northwest CSC, we have been successful at promoting and supporting the co-production of actionable climate science at the individual project level, but it has been more difficult to replicate this success at the regional program level. Here we identify the most significant challenges in satisfying this mandate and propose the creation of a Science Advisory Panel to provide improved interface between resource managers and scientists engaged with the Northwest CSC.

Environmental Management↗
USGS2016

Comments to Middle Miocene closure of the Central American Seaway

In a recent paper proposing an early (mid-Miocene) closure of the Central American Seaway (CAS), Montes et al. 2015 (1) disregard existing paleogeographic data that invalidate Panama as a source for zircons, and inappropriately ignore the evidence for trans-isthmian marine connections until 4-3 Ma. They also fail to cite previous work (2, 3), that had reconstructed the Central American arc already docked with South America by 12 Ma. Montes et al. 2015 (1) (Fig. 1) disregard the Atrato-San Juan sedimentary basin (3), a shallowing Oligocene to Pliocene, Pacific to Caribbean seaway (3, 4, 5). This deep graben (6) is filled with thousands of meters of Pre-Pliocene marine sediments (3, 5, 6) that now occupy a lowland between the Baudo uplift to the west and the Western Cordillera to the east. The Mande Batholith and numerous Eocene and younger volcanic rocks (4), the most proximal source of the zircons, are situated to the east of this seaway and would have shed zircons eastward towards the Cordillera Central. There is no evidence for any rivers crossing the seaway (3, 5), and thus no Panamanian source of zircons. Instead this seaway is evidence of a significant marine connection between the Pacific and Atlantic oceans into the Pliocene. The authors assume that the middle Miocene closure of the CAS effectively creates a continuous land bridge connecting North and South America and separating the Atlantic from the Pacific. They acknowledge, but then discount, marine connections across the Isthmus until 4-3 Ma even though these satisfactorily explain (Coates and Stallard, 2014 (6)) the oceanographic, molecular and Great American Biological Interchange events ignore unexplained by Montes et al. 2015. Only by conspicuously ignoring these events can they imply that the Isthmus was formed at 15-13 Ma. References 1. C. Montes et al., Middle Miocene closure of the Central American Seaway. Science 348, 226-229 (2015). 2. A. G. Coates, R. F. Stallard, How old is the Isthmus of Panama? B Mar Sci 89, 801-813 (2013). 3. H. Duque-Caro, The Choco Block in the northwestern corner of South America: Structural, tectonostratigraphic, and paleogeographic implications. Journal of South American Earth Sciences 3, 71-84 (1990). 4. H. Duque-Caro, Neogene stratigraphy, paleoceanography and paleobiogeography in northwest South America and the evolution of the Panama Seaway. Pal

Science↗
USGS2016

Northwest Boreal Landscape Conservation Cooperative strategic plan 2015 - 2025

The Northwest Boreal Landscape Conservation Cooperative (NWB LCC) is a voluntary, diverse, self-directed management-science partnership, informing and promoting integrated science, sustainable natural and cultural resource management, and conservation to address impacts of climate change and other stressors within and across ecosystems. The NWB LCC area includes parts of Alaska, Yukon, Northwest Territories, and British Columbia. Our partnership reflects both the broad geographic scope and an extensive array of active and engaged participants including resource management organizations, government representatives, policy makers, Tribes and First Nations, industry leaders, researchers, non-governmental organizations, and research/education institutions. Bringing together diverse partners will help assure the northwest boreal is a functioning, sustainable landscape. We live in an era of profound conservation challenges, including the loss and fragmentation of habitats, genetic isolation, invasive species, and unnatural wildfire. The effects of rapidly changing climate are already evident on the landscape. In these circumstances, it is imperative that natural resource management agencies, science providers, Tribes, First Nations, conservation organizations, and other stakeholders work together to understand the drivers and impacts of landscape change and to determine how best to address those challenges. Further, it is essential that the public and communities receive clear communication about the vision and activities of the NWB LCC. Open public access to NWB LCC activities and products will promote acceptance and support of the science that guides potential changes in management action and conservation strategy. This strategic plan provides a great opportunity for the NWB LCC to share our approach and intentions to the LCC members, collaborators, communities, and the public at large.

Report↗
USGS2005

Eolian deposits in the Neoproterozoic Big Bear Group, San Bernardino Mountains, California, USA

Strata interpreted to be eolian are recognized in the Neoproterozoic Big Bear Group in the San Bernardino Mountains of southern California, USA. The strata consist of medium- to large-scale (30 cm to > 6 m) cross-stratified quartzite considered to be eolian dune deposits and interstratified thinly laminated quartzite that are problematically interpreted as either eolian translatent climbing ripple laminae, or as tidal-flat deposits. High index ripples and adhesion structures considered to be eolian are associated with the thinly laminated and cross-stratified strata. The eolian strata are in a succession that is characterized by flaser bedding, aqueous ripple marks, mudcracks, and interstratified small-scale cross-strata that are suggestive of a tidal environment containing local fluvial deposits. The eolian strata may have formed in a near-shore environment inland of a tidal flat. The Neoproterozoic Big Bear Group is unusual in the western United States and may represent a remnant of strata that were originally more widespread and part of the hypothetical Neoproterozoic supercontinent of Rodinia. The Big Bear Group perhaps is preserved only in blocks that were downdropped along Neoproterozoic extensional faults. The eolian deposits of the Big Bear Group may have been deposited during arid conditions that preceded worldwide glacial events in the late Neoproterozoic. Possibly similar pre-glacial arid events are recognized in northern Mexico, northeast Washington, Australia, and northwest Canada.

California↗
USGS2026

Cascadia Subduction Zone science: Call for the next generation community seismic velocity model

The Cascadia subduction zone (CSZ) hosts major seismic and tsunami hazards, yet key questions persist about the relationship between margin structure, fluid distribution, episodic tremor and slip, shallow megathrust behavior, shaking and tsunamigenesis, and the resulting hazard estimates. Addressing these problems requires an empirically grounded, three‐dimensional seismic velocity model to illuminate subsurface structure and properties and to provide a basis for geophysical studies such as earthquake simulations and ground‐motion estimation. In May 2024, the National Science Foundation‐funded Cascadia Region Earthquake Science Center (CRESCENT) community velocity model (CVM) working group, with U.S. Geological Survey and regional partners, convened a workshop to identify priorities for such a model. Participants emphasized the features necessary for addressing key science questions, including implementing findability, accessibility, interoperability, and reusability (FAIR) access, capturing along‐strike and along‐dip structural heterogeneity, resolving shallow offshore–onshore structure, constraining elastic properties and quantifying their uncertainties for numerical wave propagation simulations, their validation benchmarks, and supporting associated accurate earthquake ground‐motion simulations and hazard assessments. This article describes the priorities defined in the workshop, and a description of how, guided by these needs, CRESCENT plans to develop multiple generations of a CVM to advance CSZ science and improve seismic and tsunami hazard modeling across the Pacific Northwest. The CVM will span the CSZ from the surface to ∼100 km depth, offshore and east of the Cascades into Idaho (∼132°–110° W) and the southern and northern tectonic regime transitions (∼36°–52° N) to capture the entire tectonic system as well as its surroundings.

Cascadia Subduction Zone↗