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At least 1,513 records · Page 84Linked to original sources

USGS2019

Changes in adult Chinook salmon (Oncorhynchus tshawytscha) survival within the lower Columbia River amid increasing pinniped abundance

Significant effort towards conservation has contributed to the recovery of historically depleted pinniped populations world-wide. However, in several locations where pinnipeds have increased, they have been blamed for preventing the recovery of commercially valuable fish species through predation. Prompted by increasing pinniped abundance within the Columbia River (CR) USA, over a six year period, we used Passive Integrated Transponder tags to measure the survival of adult spring-run Chinook salmon (Oncorhynchus tshawytscha) through the estuary and lower CR to Bonneville Dam (Rkm 234). We estimated 51 751 - 224 705 salmon died annually from sources other than harvest. Mixed-effects logistic regression modelling identified pinniped predation as the most likely source. The odds of survival was estimated to decrease by 32% (95% CI: 6%-51% decrease) for every additional 467 sea lions, and to increase by 32% (95% CI: 8%-61% increase) for every increase of 1.5 in the log of American shad (Alosa sapidissima), a potential prey item for sea lions. A third covariate was the adipose clip status of the fish, indicating whether it was eligible for harvest.

Oregon, Washington↗

USGS2024

Differences in life history patterns of American shad, Alosa sapidissima, populations between ancestral, Atlantic coast, and non-native, Pacific coast rivers of North America

Organisms naturalized outside their native range can reveal new life history patterns in new environments. Here, we compare life history patterns of American shad, Alosa sapidissima, from five rivers along the U.S. Pacific coast (introduced range) with contemporary data from the Atlantic coast source populations. The Pacific coast fish grew slower, matured at a younger age, and were less often iteroparous than conspecifics from the Hudson River and Susquehanna River sources. Differences among the Pacific coast populations indicated that some combination of phenotypic plasticity and genetic adaptation has occurred since the transplants in the 1870s. Microchemical analysis of otoliths from returning adults demonstrated an immature, extended freshwater life history form, locally known as “mini-shad”. These fish remain in the river for at least 1 year or enter salt water briefly and then return to fresh water for several months prior to subsequent seaward migration and return as adults. This and other forms of variation (extent of estuary use and size at sea water entry) expand the understanding of Alosine migration and life history diversity.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS2018

Annual cycle of White-winged Scoters (Melanitta fusca) in eastern North America: Migratory phenology, population delineation, and connectivity

Understanding full annual cycle movements of long-distance migrants is essential for delineating populations, assessing connectivity, evaluating crossover effects between life stages, and informing management strategies for vulnerable or declining species. We used implanted satellite transmitters to track up to 2 years of annual cycle movements of 52 adult female White-winged Scoters ( Melanitta fusca (Linnaeus, 1758)) captured in the eastern United States and Canada. We used these data to document annual cycle phenology; delineate migration routes; identify primary areas used during winter, stopover, breeding, and molt; and assess the strength of migratory connectivity and spatial population structure. Most White-winged Scoters wintered along the Atlantic coast from Nova Scotia to southern New England, with some on Lake Ontario. White-winged Scoters followed four migration routes to breeding areas from Quebec to the Northwest Territories. Principal postbreeding molting areas were in James Bay and the St. Lawrence River estuary. Migration phenology was synchronous regardless of winter or breeding origin. Cluster analyses delineated two primary breeding areas: one molting area and one wintering area. White-winged Scoters demonstrated overall weak to moderate connectivity among life stages, with molting to wintering connectivity the strongest. Thus, White-winged Scoters that winter in eastern North America appear to constitute a single continuous population.

Canadian Journal of Zoology↗

USGS2004

Migration and rearing histories of chinook salmon (Oncorhynchus tshawytscha) determined by ion microprobe Sr isotope and Sr/Ca transects of otoliths

Strontium isotope and Sr/Ca ratios measured in situ by ion microprobe along radial transects of otoliths of juvenile chinook salmon ( Oncorhynchus tshawytscha ) vary between watersheds with contrasting geology. Otoliths from ocean-type chinook from Skagit River estuary, Washington, had prehatch regions with 87 Sr/ 86 Sr ratios of ~0.709, suggesting a maternally inherited marine signature, extensive fresh water growth zones with 87 Sr/ 86 Sr ratios similar to those of the Skagit River at ~0.705, and marine-like 87 Sr/ 86 Sr ratios near their edges. Otoliths from stream-type chinook from central Idaho had prehatch 87 Sr/ 86 Sr ratios ≥0.711, indicating that a maternal marine Sr isotopic signature is not preserved after the ~1000- to 1400-km migration from the Pacific Ocean. 87 Sr/ 86 Sr ratios in the outer portions of otoliths from these Idaho juveniles were similar to those of their respective streams (~0.7080.722). For Skagit juveniles, fresh water growth was marked by small decreases in otolith Sr/Ca, with increases in Sr/Ca corresponding to increases in 87 Sr/ 86 Sr with migration into salt water. Otoliths of Idaho fish had Sr/Ca radial variation patterns that record seasonal fluctuation in ambient water Sr/Ca ratios. The ion microprobe's ability to measure both 87 Sr/ 86 Sr and Sr/Ca ratios of otoliths at high spatial resolution in situ provides a new tool for studies of fish rearing and migration.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS1997

Age and significance of earthquake-induced liquefaction near Vancouver, British Columbia, Canada

In late 1994, sand dykes, large sand blows, and deformed strata were exposed in the walls of an excavation at Annacis Island on the Fraser River delta near Vancouver, British Columbia. The features record liquefaction during a large earthquake about 1700 years ago; this was perhaps the largest earthquake to affect the Vancouver area in the last 3500 years. Similar, less well-dated features have been reported from several other sites on the Fraser delta and may be products of the same earthquake. Three radiocarbon ages that closely delimit the time of liquefaction on Annacis Island are similar to the most precise radiocarbon ages on coseismically subsided marsh soils at estuaries in southern Washington and Oregon. Both the liquefaction and the subsidence may have been produced by a single great plate-boundary earthquake at the Cascadia subduction zone. Alternatively, liquefaction at Annacis Island may have been caused by a large crustal or subcrustal earthquake of about the same age as a plate-boundary earthquake farther west. The data from Annacis Island and other sites on the Fraser delta suggest that earthquakes capable of producing extensive liquefaction in this area are rare events. Further, liquefaction analysis using historical seismicity suggests that current assessment procedures may overestimate liquefaction risk.

British Columbia↗

USGS2016

Pockmarks in Passamaquoddy Bay, New Brunswick, Canada

Pockmarks are seafloor depressions associated with fluid escape ( Judd & Hovland 2007 ). They proliferate in the muddy seafloors of coastal Gulf of Maine and Bay of Fundy, where they are associated with shallow natural gas likely of biogenic origin ( Ussler et al. 2003 ; Rogers et al. 2006 ; Wildish et al. 2008 ). In North America, shallow-water pockmark fields are not reported south of Long Island Sound, despite the abundance of gassy, muddy estuaries. The absence of pockmarks south of the limit of North American glaciation suggests that local and regional heterogeneities, possibly related to glacial or sea-level history or bedrock geology, influence pockmark field distribution. In shallow-water embayments, such as Passamaquoddy Bay, New Brunswick, pockmarks can be large (>200 m diameter) and number in the thousands.

New Brunswick↗

USGS2022

Early Pliocene marine transgression into the lower Colorado River valley, southwestern USA, by re-flooding of a former tidal strait

Marine straits and seaways are known to host a wide range of sedimentary processes and products, but the role of marine connections in the development of large river systems remains little studied. This study explores a hypothesis that shallow-marine waters flooded the lower Colorado River valley at c. 5 Ma along a fault-controlled former tidal strait, soon after the river was first integrated into the northern Gulf of California. The upper bioclastic member of the southern Bouse Formation provides a critical test of this hypothesis. The upper bioclastic member contains wave ripple-laminated bioclastic grainstone with minor red mudstone, pebbly grainstone with hummocky cross-stratification (HCS)-like stratification and symmetrical gravelly ripples, and calcareous-matrix conglomerate. Fossils include upward-branching segmented coralline-like red algae with no known modern relatives but confirmed as marine calcareous algae, echinoid spines, barnacles, shallow-marine foraminifers, clams, and serpulid worm tubes. These results provide evidence for deposition in a shallow-marine bay or estuary seaward of the transgressive backstepping Colorado River delta. Tsunamis generated by seismic and meteorological sources likely produced the HCS-like and wave-ripple cross-bedding in poorly-sorted gravelly grainstone. Marine waters inundated a former tidal strait within a fault-bounded tectonic lowland that connected the lower Colorado River to the Gulf of California. Delta backstepping and transgression resulted from a decrease in sediment output due to sediment trapping in upstream basins and relative sea-level rise produced by regional tectonic subsidence.

Arizona, California↗

USGS2002

Structure and flow-induced variability of the subtidal salinity field in northern San Francisco Bay

The structure of the salinity field in northern San Francisco Bay and how it is affected by freshwater flow are discussed. Two datasets are examined: the first is 23 years of daily salinity data taken by the U.S. Bureau of Reclamation along the axis of northern San Francisco Bay; the second is a set of salinity transects taken by the U.S. Geological Survey between 1988 and 1993. Central to this paper is a measure of salinity intrusion, X 2 : the distance from the Golden Gate Bridge to where the bottom salinity is 2 psu. Using X 2 to scale distance, the authors find that for most flow conditions, the mean salinity distribution of the estuary is nearly self-similar with a salinity gradient in the center 70% of the region between the Golden Gate and X 2 that is proportional to X −1 2 . Analysis of covariability of Q and X 2 showed a characteristic timescale of adjustment of the salinity field of approximately 2 weeks. The steady-state response deduced from the X 2 time series implies that X 2 is proportional to riverflow to the 1/7 power. This relation, which differs from the standard 1/3 power dependence that is derived theoretically assuming constant exchange coefficients, shows that the upstream salt flux associated with gravitational circulation is more sensitive to the longitudinal salinity gradient than theory supposes. This is attributed to the strengthening of stratification caused by the stronger longitudinal salinity gradient that accompanies larger river flows.

California↗

USGS2017

Engaging the user community for advancing societal applications of the Surface Water Ocean Topography mission

Scheduled for launch in 2021, the Surface Water and Ocean Topography (SWOT) mission will be a truly unique mission that will provide high-temporal-frequency maps of surface water extents and elevation variations of global water bodies (lakes/reservoirs, rivers, estuaries, oceans, and sea ice) at higher spatial resolution than is available with current technologies (Biancamaria et al. 2016; Alsdorf et al. 2007). The primary instrument on SWOT is based on a Ka-band radar interferometer (KaRIN), which uses radar interferometery technology. The satellite will fly two radar antennas at either end of a 10-m (33 ft) mast, allowing it to measure the elevation of the surface along a 120-km (75 mi)-wide swath below. The availability of high-frequency and high-resolution maps of elevations and extents for surface water bodies and oceans will present unique opportunities to address numerous societally relevant challenges around the globe (Srinivasan et al. 2015). These opportunities may include such diverse and far-ranging applications as fisheries management, flood inundation mapping/risk mitigation/forecasting, wildlife conservation, global data assimilation for improving forecast of ocean tides and weather, reservoir management, climate change impacts and adaptation, and river discharge estimation, among others. Although SWOT is a research mission and not scheduled for launch for another 4 years, there is a need to build engagement within the application community now and to explore how best to advance the societal relevance and benefits of the SWOT mission from concept to reality. The SWOT Applications Working Group organized a workshop on 5–6 April 2017 at the U.S. Geological Survey (USGS) headquarters in Reston, Virginia. The goal of the workshop was to understand and communicate how the applications community can use SWOT data to address problems of profound societal relevance.

Bulletin of the American Meteorological Society↗

USGS2023

Observing coastal wetland transitions using national land cover products

Over the coming century, climate change and sea-level rise are predicted to cause widespread change to coastal wetlands. Estuarine vegetated wetlands can adapt to sea-level rise through both vertical development (i.e., biophysical feedbacks and sedimentation) and upslope/horizontal migration. Quantifying changes to estuarine vegetated wetlands over time can help to inform current and future decisions regarding land management and resource stewardship. In this study, we show how coastal land cover maps readily available in the US can be used to assess and understand estuarine vegetated wetland changes. This assessment involves two steps: (1) identifying the net gain/loss of estuarine vegetated wetlands and (2) determining which land cover types contribute to the net gain/loss. From this information, we developed estuarine vegetated wetland change scenarios that evaluate whether estuarine vegetated wetland gain kept up with loss and whether the contribution was from: (1) estuarine vegetated wetland migration or tidal restoration; (2) land building (i.e., development); or (3) both. We assessed changes from 1996 to 2016 for: (1) the conterminous US; (2) each major US coastline; and (3) focal estuaries with the most change per coast. We found that the change scenario (1, 2, or 3) varied across coastlines. Moving forward, national coastal land cover programs can be informed by utilizing methodologies that leverage contemporary information for delineating the estuarine zone from upslope/adjacent wetlands. We highlight approaches that could be used to address this challenge and provide complementary information related to wetland condition changes.

Progress in Physical Geography: Earth and Environm↗

USGS1996

Diatoms as an aid in identifying late-holocene tsunami deposits

Diatoms (Bacillariophyta) help identify the onshore deposits of tsunamis from earthquakes on the Cascadia subduction zone along the Pacific coast of Oregon, Washington, and British Columbia, and on faults high in the North American plate in the Puget Sound area of Washington. At the Copalis River, Washington, diatom analyses suggest that a tsunami deposit about 300 calendric years old (300 yr BP) originated from sandy shoals of the lower estuary rather than nearby beaches or coastal dunes. At Cultus Bay and West Point, Washington, well-preserved benthic estuarine diatoms in sand sheets overlying tidal-marsh peat indicate that the deposits came from intertidal or nearshore areas of Puget Sound. On an abruptly uplifted mudflat at the landward end of Hood Canal at Lynch Cove, Washington, tidal-flat diatoms refute the possibility of a terrestrial source for the sand. Diatoms in 300-yr-BP tsunami deposits on the Niawiakum River, Washington, confirm that the sand in these deposits had a marine source, and help to identify the landward extent of tsunami inundation. Diatom assemblages in deposits of the 300 yr BP and AD 1964 tsunamis at Port Alberni, British Columbia, consist of different dominant taxa, but both indicate that the sand units originated from Alberni Inlet. Diatoms add to stratigraphic evidence that tsunamis flooded Bradley Lake, a freshwater lake on the south-central Oregon coast, three times during the past 1700 years. Planktonic marine diatoms only found above 1-70-cm-thick sand layers in otherwise clayey lacustrine sediment imply tsunami inundation.

Holocene↗

USGS2016

Toward a national animal telemetry network for aquatic observations in the United States

Animal telemetry is the science of elucidating the movements and behavior of animals in relation to their environment or habitat. Here, we focus on telemetry of aquatic species (marine mammals, sharks, fish, sea birds and turtles) and so are concerned with animal movements and behavior as they move through and above the world’s oceans, coastal rivers, estuaries and great lakes. Animal telemetry devices (“tags”) yield detailed data regarding animal responses to the coupled ocean–atmosphere and physical environment through which they are moving. Animal telemetry has matured and we describe a developing US Animal Telemetry Network (ATN) observing system that monitors aquatic life on a range of temporal and spatial scales that will yield both short- and long-term benefits, fill oceanographic observing and knowledge gaps and advance many of the U.S. National Ocean Policy Priority Objectives. ATN has the potential to create a huge impact for the ocean observing activities undertaken by the U.S. Integrated Ocean Observing System (IOOS) and become a model for establishing additional national-level telemetry networks worldwide.

Animal Biotelemetry↗

USGS2012

Air-water oxygen exchange in a large whitewater river

Air–water gas exchange governs fluxes of gas into and out of aquatic ecosystems. Knowing this flux is necessary to calculate gas budgets (i.e., O 2 ) to estimate whole‐ecosystem metabolism and basin‐scale carbon budgets. Empirical data on rates of gas exchange for streams, estuaries, and oceans are readily available. However, there are few data from large rivers and no data from whitewater rapids. We measured gas transfer velocity in the Colorado River, Grand Canyon, as decline in O 2 saturation deficit, 7 times in a 28‐km segment spanning 7 rapids. The O 2 saturation deficit exists because of hypolimnetic discharge from Glen Canyon Dam, located 25 km upriver from Lees Ferry. Gas transfer velocity ( k 600 ) increased with slope of the immediate reach. k 600 was < 10 cm h − 1 in flat reaches, while k 600 for the steepest rapid ranged 3600–7700 cm h − 1 , an extremely high value of k 600 . Using the rate of gas exchange per unit length of water surface elevation ( K drop , m − 1 ), segment‐integrated k 600 varied between 74 and 101 cm h − 1 . Using K drop we scaled k 600 to the remainder of the Colorado River in Grand Canyon. At the scale corresponding to the segment length where 80% of the O 2 exchanged with the atmosphere (mean length = 26.1 km), k 600 varied 4.5‐fold between 56 and 272 cm h − 1 with a mean of 113 cm h − 1 . Gas transfer velocity for the Colorado River was higher than those from other aquatic ecosystems because of large rapids. Our approach of scaling k 600 based on K drop allows comparing gas transfer velocity across rivers with spatially heterogeneous morphology.

Arizona↗

USGS2008

Flow unit modeling and fine-scale predicted permeability validation in Atokan sandstones: Norcan East Kansas

Characterizing the reservoir interval into flow units is an effective way to subdivide the net-pay zone into layers for reservoir simulation. Commonly used flow unit identification techniques require a reliable estimate of permeability in the net pay on a foot-by-foot basis. Most of the wells do not have cores, and the literature is replete with different kinds of correlations, transforms, and prediction methods for profiling permeability in pay. However, for robust flow unit determination, predicted permeability at noncored wells requires validation and, if necessary, refinement. This study outlines the use o f a spreadsheet-based permeability validation technique to characterize flow units in wells from the Norcan East field, Clark County, Kansas, that produce from Atokan aged fine- to very fine-grained quartzarenite sandstones interpreted to have been deposited in brackish-water, tidally dominated restricted tidal-flat, tidal-channel, tidal-bar, and estuary bay environments within a small incised-valley-fill system. The methodology outlined enables the identification of fieldwide free-water level and validates and refines predicted permeability at 0.5-ft (0.15-m) intervals by iteratively reconciling differences in water saturation calculated from wire-line log and a capillary-pressure formulation that models fine- to very fine-grained sandstone with diagenetic clay and silt or shale laminae. The effectiveness of this methodology was confirmed by successfully matching primary and secondary production histories using a flow unit-based reservoir model of the Norcan East field without permeability modifications. The methodologies discussed should prove useful for robust flow unit characterization of different kinds of reservoirs. Copyright ?? 2008. The American Association of Petroleum Geologists. All rights reserved.

American Association of Petroleum Geologists Bulle↗

USGS1977

Clay-mineral variability in the suspended sediments of the San Francisco Bay system, California

Semiquantitative determinations of the clay-mineral composition have been made on nearly synoptic samples of surface suspended sediments collected seasonally throughout the San Francisco Bay system. The relative amounts of chlorite + kaolinite are generally highest in the northern reach of the system, whereas illite is dominant in the southern reach. The proportion of montmorillonite is low throughout the bay. Time-series and replicate samples collected at individual stations show that the difference in clay-mineral content between reaches is real and reflects a change in the source of clay-mineral particles within the bay. The Sacramento-San Joaquin river system supplies the northern reach, whereas most clay-mineral particles come from resuspension by waves and tidal currents in the southern reach. Analyses of bottom sediments and the spatial variability in the northern reach suggest that the relationship between the abundance and sources of clay minerals may, in turn, be a function of particle size. This study demonstrates the utility of suspended clay minerals in the interpretation of sediment-dispersal patterns in estuaries.

California↗

USGS1982

A new instrument for sampling flocculent material at the water/sediment interface

We have designed an instrument to collect fine-grained and flocculent material from the water/sediment interface for chemical and mineralogical analysis. The sampler can be used from a manned research submersible or by a diver in shallow water. In areas of active deposition, the material collected represents the most recently deposited sediment. This material is of interest for determining the concentration of anthropogenic contaminants at the sea floor and may be a much more sensitive indicator of early contamination than are bulk samples collected by means of conventional grab samplers or corers. The instrument also may be well suited for sampling freshly flocculated or precipitated material from the sea floor, for example in estuaries or around thermal vents on mid ocean ridges.

Journal of Sedimentary Research↗

USGS1991

Modern sedimentary environments in Boston Harbor, Massachusetts

Analyses of sidescan-sonar records supplemented by available bathymetric, sedimentary, subbottom, and bottom-current data reveal the distributions of the following three categories of sedimentary environments within the glaciated, topographically complex Boston Harbor estuary in Massachusetts. 1) Environments of erosion appear on the sonographs either as patterns with isolated strong reflections or as uniform patterns of strong reflectivity. These patterns define outcrops of bedrock or till and coarse lag deposits that are being scoured and winnowed by tidal- and wave-induced currents. Erosional areas are located primarily along mainland and insular shores, within large channels that have strong tidal currents, atop submerged ridges and knolls, and across much of the harbor entrance. 2) Environments of deposition are depicted on the sidescan-sonar records as smooth, featureless surfaces that have low to moderate reflectivity. Depositional environments are found predominantly over shallow subtidal flats and in broad bathymetric lows where tidal currents are weak. Sediments within depositional areas are organic-rich sandy and clayey silts that are accumulating at rates ranging from 0.01 to 0.11 g/cm 2 /yr or 4000 to 46,100 metric tons/yr. The cumulative mass of modern mud in harbor depocenters is 24.3 million metric tons. 3) Environments of sediment reworking constitute areas affected by a combination of erosional and depositional processes. They are characterized on the sonographs by mosaics of light and dark patches produced by relatively subtle and gradational changes in reflectivity. Reworked sediments have diverse grain sizes that overlap and are transitional between those of the other two sedimentary environments, and they are indicative of highly variable bottom currents.

Massachusetts↗

USGS2021

Long-term changes in kelp forests in an inner basin of the Salish Sea

Kelp forests form an important biogenic habitat that responds to natural and human drivers. Global concerns exist about threats to kelp forests, yet long-term information is limited and research suggests that trends are geographically distinct. We examined distribution of the bull kelp Nereocystis luetkeana over 145 years in South Puget Sound (SPS), a semi-protected inner basin in a fjord estuary complex in the northeast Pacific Ocean. We synthesized 48 historical and modern Nereocystis surveys and examined presence/absence within 1-km segments along 452 km of shoreline. Compared to the earliest baseline in 1878, Nereocystis extent in 2017 decreased 63%, with individual sub-basins showing up to 96% loss. Losses have persisted for decades, across a range of climate conditions. In recent decades, Nereocystis predominantly occurred along shorelines with intense currents and mixing, where temperature and nutrient concentrations did not reach thresholds for impacts to Nereocystis performance, and high current speeds likely excluded grazers. Losses predominated in areas with elevated temperature, lower nutrient concentrations, and relatively low current velocities. The pattern of long-term losses in SPS contrasts with stability in floating kelp abundance during the last century in an area of the Salish Sea with greater wave exposure and proximity to oceanic conditions. These findings support the hypothesis that kelp beds along wave-sheltered shorelines exhibit greater sensitivity to environmental stressors. Additionally, shorelines with strong currents and deep-water mixing may provide refugia within sheltered systems.

Washington↗