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At least 1,657 records · Page 92Linked to original sources
USGS2006

Effects of tributary debris on the longitudinal profile of the Colorado River in Grand Canyon

The Colorado River in Grand Canyon has long been known as a "rapids-and-pools" river, with the rapids owing their existence primarily to tributary debris flows. The debris flows deposit subaerial debris fans that constrict the channel laterally and, when they enter the river, raise the bed elevation. The rapids are short-wavelength (???0.1 to ???1 km), small-amplitude (??????5 m) convexities in the river's longitudinal profile, arising from the shallow gradient in the upstream pool and the steep gradient through the rapid itself. Analysis of the entire longitudinal profile through Grand Canyon reveals two long-wavelength (???100 km), large-amplitude (15-30 m) river profile convexities: the eastern canyon convexity between river mile (RM) 30 and RM 80 and the western canyon convexity between RM 150 and RM 250. Convexities of intermediate scale are also identified in the longitudinal profile. These longer-wavelength, larger-amplitude convexities have strong spatial correlations with high rates of debris flow occurrence, high densities of Holocene debris fans, the largest debris fans along the river, and alluvial thicknesses of 10 m or more. River profile convexities are unstable and require an active and powerful geologic process to maintain them, in this case the abundant, frequent, and voluminous Holocene debris flow activity in Grand Canyon. At all wavelengths the most likely cause for these river profile convexities is Holocene aggradation of the riverbed beneath them, driven by the coarse particles of tributary debris flows. Large enough debris flows will slow river flow for kilometers upstream, causing it to drop much of its suspended load. Integrated over time and all of the tributary point source contributions, this process will build short-wavelength convexities into long-wavelength convexities. For most if not all of the Holocene the Colorado River has been dissipating most of its energy in the rapids and expending the remainder in transporting fine sediment through Grand Canyon, with little or no regional incision of bedrock.

Journal of Geophysical Research F: Earth Surface↗
USGS2025

Dynamic feedbacks between river meandering and landsliding in northwestern Washington glacial terraces

Landsliding in river valleys poses unique risks for cascading hazards and can damage infrastructure and cause fatalities. In postglacial valleys, many landslides are posited to occur in relation to lateral river erosion, but the dynamics of fluvial-hillslope interactions are not well understood. Here, we investigate a section of the Nooksack River in western Washington State where the channel is flanked by landslide-prone glacial terraces similar to those that failed in the 2014 State Route 530 “Oso” landslide. We map 216 landslides through time across 17 aerial imagery data sets (1933–2022) and analyze them in relation to river meandering and curvature. We observe dynamic feedbacks between lateral river meandering and valley-adjacent landsliding. Terrace lateral retreat rates of up to 25 m/year owing to combined fluvial erosion and slope failure occur on pinned, outer meander bends immediately downstream from peaks in river curvature (>0.0075 1/m); these locations are predisposed to both shallow and deep-seated landslides. Deep-seated landslides extending 17%–32% of the active valley width into the floodplain can displace the river away from the floodplain margin and change the channel planform. River-displacing landslides relocate meanders up- or downstream, thereby conditioning the location of subsequent landslides. This conceptual model of coupled landslide-driven meander displacement and valley-adjacent landsliding is exemplified across western Washington river systems. The distance between up- and downstream valley-adjacent landsliding scales with valley width, meander wavelength, and terrace height. Our results can advance our understanding of the river-hillslope interface in landscape evolution and can be used to inform hazard management in river corridors.

Washington↗
USGS2010

Groundwater as a nonpoint source of atrazine and deethylatrazine in a river during base flow conditions

Alluvial groundwater adjacent to the main stem river is the principal nonpoint source of atrazine and deethylatrazine in the Cedar River of Iowa after the river has been in base flow conditions for 5 days. Between two sites along a 116-km reach of the Cedar River, tributaries contributed about 25% of the increase in the atrazine and deethylatrazine load, whereas groundwater from the alluvial aquifer contributed at least 75% of the increase in load. Within the study area, tributaries aggregate almost all of the discharge from tile drains, and yet the tributaries still only contribute 25% of the increase in loads in the main stem river. At an unfamned study site adjacent to the Cedar River, the sources of atrazine and deethylatrazine in the alluvial groundwater are bank storage of river water and groundwater recharge from areas distant from the river. Atrazine and deethylatrazine associated with bank storage water will provide larger concentrations to the river during early base flow conditions. After the depletion of bank storage, stable and smaller concentrations of atrazine and deethylatrazine, originating from groundwater recharge, continue to be discharged from the alluvial aquifer to the river; thus these results indicate that alluvial aquifers are an important nonpoint source of atrazine and deethylatrazine in rivers during base flow.

Iowa↗
USGS2015

Diel patterns and temporal trends in spawning activities of Robust Redhorse and River Redhorse in Georgia, assessed using passive acoustic monitoring

The conservation of imperiled species depends upon understanding threats to the species at each stage of its life history. In the case of many imperiled migratory fishes, understanding how timing and environmental influences affect reproductive behavior could provide managers with information critical for species conservation. We used passive acoustic recorders to document spawning activities for two large-bodied catostomids (Robust Redhorse Moxostoma robustum in the Savannah and Broad rivers, Georgia, and River Redhorse M. carinatum in the Coosawattee River, Georgia) in relation to time of day, water temperature, discharge variation, moonlight, and weather. Robust Redhorse spawning activities in the Savannah and Broad rivers were more frequent at night or in the early morning (0100–0400 hours and 0800–1000 hours, respectively) and less frequent near midday (1300 hours). Spawning attempts in the Savannah and Broad rivers increased over a 3–4-d period and then declined. River Redhorse spawning activities in the Coosawattee River peaked on the first day of recording and declined over four subsequent days; diel patterns were less discernible, although moon illumination was positively associated with spawning rates, which was also observed for Robust Redhorses in the Savannah River. Spawning activity in the Savannah and Broad rivers was negatively associated with water temperature, and spawning activity increased in association with cloud cover in the Savannah River. A large variation in discharge was only measured in the flow-regulated Savannah River and was not associated with spawning attempts. To our knowledge, this is the first study to show diel and multiday patterns in spawning activities for any Moxostoma species. These patterns and relationships between the environment and spawning activities could provide important information for the management of these species downstream of hydropower facilities.

Georgia↗
USGS2016

Comparative use of side and main channels by small-bodied fish in a large, unimpounded river

Ecological theory and field studies suggest that lateral floodplain connectivity and habitat heterogeneity provided by side channels impart favourable habitat conditions for lotic fishes, especially fluvial fishes dependent on large patches of shallow, slow velocity habitats for some portion of their life cycle. However, anthropogenic modification of large, temperate floodplain rivers has led to extensive channel simplification and side-channel loss. Highly modified rivers consist of simplified channels in contracted, less dynamic floodplains. Most research examining the seasonal importance of side channels for fish assemblages in large rivers has been carried out in heavily modified rivers, where side-channel extents are substantially reduced from pre-settlement times, and has often overlooked small-bodied fishes. Inferences about the ecological importance of side channels for small-bodied fishes in large rivers can be ascertained only from investigations of large rivers with largely intact floodplains. The Yellowstone River, our study area, is a rare example of one such river. We targeted small-bodied fishes and compared their habitat use in side and main channels in two geomorphically distinct types of river bends during early and late snowmelt runoff, and autumn base flow. Species compositions of side and main channels differed throughout hydroperiods concurrent with the seasonal redistribution of the availability of shallow, slow current-velocity habitats. More species of fish used side channels than main channels during runoff. Additionally, catch rates of small fishes were generally greater in side channels than in main channels and quantitative assemblage compositions differed between channel types during runoff, but not during base flow. Presence of and access to diverse habitats facilitated the development and persistence of diverse fish assemblages in our study area. Physical dissimilarities between side and main channels may have differentially structured the side- and main-channel fish assemblages during runoff. Patches of shallow, slow current-velocity (SSCV) habitats in side channels were larger and had slightly slower water velocities than SSCV habitat patches in main channels during runoff, but not during base flow. Our findings establish a baseline importance of side channels to riverine fishes in a large, temperate river without heavy anthropogenic modification. Establishing this baseline contributes to basic fluvial ecology and provides empirical justification for restoration efforts that reconnect large rivers with their floodplains.

Montana↗
USGS2012

Life history characteristics of a recovering lake whitefish Coregonus clupeaformis stock in the Detroit River, North America

The Detroit River is part of a channel connecting Lakes Huron and Erie and was once a prolific spawning area for lake whitefish, Coregonus clupeaformis . Large numbers of lake whitefish migrated into the river to spawn where they were harvested by commercial fisheries and for fish culture operations. Prior to our study, the last lake whitefish was landed from the Detroit River in 1925. Loss of spawning habitat during shipping channel construction and over-fishing, likely reduced lake whitefish spawning runs. Because lake whitefish are recovering in Lake Erie, and spawning in the western basin, we suspected they may also be spawning in the Detroit River. We sampled in the Detroit River for lake whitefish adults and eggs in October–December 2005–07 and for larvae during March–May 2006–08. A total of 15 spawning-ready lake whitefish from 4 to 18 years old, were collected. Viable eggs were collected during mid-November 2006–07; highest egg densities were found mid-river. Sac-fry whitefish larvae were collected in the river and near the river mouth. No whitefish larvae were retained in the river. Because high numbers of larvae were collected from mid- and downstream river sites, reproduction of lake whitefish in the Detroit River could contribute substantially to the Lake Erie lake whitefish metapopulation.

Michigan, Ontario↗
USGS1990

The late Cenozoic evolution of the Tuolumne River, central Sierra Nevada, California

Erosional remnants of volcanic rock deposited in a lO-m.y.-old channel of the Tuolumne River permit its partial reconstruction. Projection of the reconstructed channel west to the Central Valley and east to the range crest, together with several assumptions about the position of the hinge line and changes in channel gradient, allows estimates of the amount of uplift at the range crest during the past 10 m.y. At Tioga Pass, this amounts to as much as 1,830 m, as compared to the 2,150 m estimated in an earlier study for Deadman Pass at the San Joaquin River 30 km to the south. Comparison of the geometry of these river systems leads to the conclusion that 10 m.y. ago an ancestral range of hills occupied the present site of the Sierran crest, and, although of relatively moderate relief, it was a barrier to westward drainage even before late Cenozoic uplift. At that time, the San Joaquin River was apparently the only river flowing westward across the range from well south of Mount Whitney north to Sonora Pass. The Tuolumne River evidently never extended east of this range. Comparison of the ancient channel with the modern channel of the Tuolumne River permits analysis of the later evolution of the river system and the development of Hetch Hetchy Valley and the Grand Canyon of the Tuolumne. At Rancheria Mountain, where the volcanic "dam" in the ancient channel was highest, the river was forced to shift laterally southward around the dam and adjacent to the volcanic infilling, and start its new channel in granitic bedrock. Near Rancheria Mountain, as much as 1,525 m of new channel incision has taken place in the past 10 m.y., and the modern channel is about 915 m lower than the abandoned channel. An undetermined amount of this downcutting was from glacial erosion. The Tuolumne river system provides no direct evidence for timing the onset of uplift, but the shape of the lO-m.y.-old channel at Rancheria Mountain suggests that uplift had been underway for some time before the volcanic infilling. This timing is compatible with evidence from the upper San Joaquin River. Hetch Hetchy Valley on the Tuolumne is a much "fresher" glaciated valley than is Yosemite Valley. Hetch Hetchy was filled to the brim with glacial ice as recently as 15,000-20,000 yr ago (Tioga glaciation), whereas Yosemite Valley probably has not been filled for 750,000 yr or more (Sherwin glaciation). Thus the upper reaches of Yosemite Valley cliffs have been shaped by spalling rather than by glacial scour and are much more irregular than those in Hetch Hetchy.

California↗
USGS2007

Crustal controls on magmatic-hydrothermal systems: A geophysical comparison of White River, Washington, with Goldfield, Nevada

The White River altered area, Washington, and the Goldfield mining district, Nevada, are nearly contemporaneous Tertiary (ca. 20 Ma) calc-alkaline igneous centers with large exposures of shallow (<1 km depth) magmatic-hydrothermal, acid-sulfate alteration. Goldfield is the largest known high-sulfidation gold deposit in North America. At White River, silica is the only commodity exploited to date, but, based on its similarities with Goldfield, White River may have potential for concealed precious and/or base metal deposits at shallow depth. Both areas are products of the ancestral Cascade arc. Goldfield lies within the Great Basin physiographic province in an area of middle Miocene and younger Basin and Range and Walker Lane faulting, whereas White River is largely unaffected by young faults. However, west-northwest–striking magnetic anomalies at White River do correspond with mapped faults synchronous with magmatism, and other linear anomalies may reflect contemporaneous concealed faults. The White River altered area lies immediately south of the west-northwest–striking White River fault zone and north of a postulated fault with similar orientation. Structural data from the White River altered area indicate that alteration developed synchronously with an anomalous stress field conducive to left-lateral, strike-slip displacement on west-northwest–striking faults. Thus, the White River alteration may have developed in a transient transtensional region between the two strike-slip faults, analogous to models proposed for Goldfield and other mineral deposits in transverse deformational zones. Gravity and magnetic anomalies provide evidence for a pluton beneath the White River altered area that may have provided heat and fluids to overlying volcanic rocks. East– to east-northeast–striking extensional faults and/or fracture zones in the step-over region, also expressed in magnetic anomalies, may have tapped this intrusion and provided vertical and lateral transport of fluids to now silicified areas. By analogy to Goldfield, geophysical anomalies at the White River altered area may serve as proxies for geologic mapping in identifying faults, fractures, and intrusions relevant to hydrothermal alteration and ore formation in areas of poor exposure.

Nevada, Washington↗
USGS1996

Incidence of Renibacterium salmoninarum infections in juvenile hatchery spring chinook salmon in the Columbia and Snake Rivers

From 1988 through 1992, we assessed the prevalence (frequency of occurrence) and severity (degree of infection) of Renibacterium salmoninarum (RS) among fish in marked groups of Columbia River basin and Snake River basin hatchery spring chinook salmon Oncorhynchus tshawytscha before release and during their seaward migration. During the study, prevalence of RS infection decreased (from >90% to <65%) in six of the eight hatchery groups. We attributed this decrease to changes in hatchery practices that reduced vertical and horizontal transmission. Fish from Snake River hatcheries had a higher prevalence of infection when sampled at dams (mean >90%) than in the hatchery (mean <70%), but there were no differences in similar comparisons of Columbia River fish. Although prevalence and severity of RS infection were not correlated in the groups studied, it appears that fish from the Snake River were more severely infected than those from the Columbia River. Some groups of Snake River fish had higher severity of infection at dams than in the hatchery, but infection in fish from Columbia River hatcheries did not change. These differences between Snake River and Columbia River fish might have resulted from differences in river conditions and the distances from hatcheries to dams.

Oregon, Washington↗
USGS2018

Changes in freshwater mussel communities linked to legacy pollution in the Lower Delaware River

Freshwater mussels are among the most-imperiled organisms worldwide, although they provide a variety of important functions in the streams and rivers they inhabit. Among Atlantic-slope rivers, the Delaware River is known for its freshwater mussel diversity and biomass; however, limited data are available on the freshwater mussel fauna in the lower, non-tidal portion of the river. This section of the Delaware River has experienced decades of water-quality degradation from both industrial and municipal sources, primarily as a function of one of its major tributaries, the Lehigh River. We completed semi-quantitative snorkel surveys in 53.5 of the 121 km of the river to document mussel community composition and the continued impacts from pollution (particularly inputs from the Lehigh River) on mussel fauna. We detected changes in mussel catch per unit effort (CPUE) below the confluence of the Lehigh River, with significant declines in the dominant species Elliptio complanata (Eastern Elliptio) as we moved downstream from its confluence—CPUE dropped from 179 to 21 mussels/h. Patterns in mussel distribution around the Lehigh confluence matched chemical signatures of Lehigh water input. Specifically, Eastern Elliptio CPUE declined more quickly moving downstream on the Pennsylvania bank, where Lehigh River water input was more concentrated compared to the New Jersey bank. A definitive causal link remains to be established between the Lehigh River and the dramatic shifts in mussel community composition, warranting continued investigation as it relates to mussel conservation and restoration in the basin.

Lower Delaware River↗
USGS1970

Taunton River basin

The Taunton River, emptying into an arm of Narragansett Bay at Fall River, drains 528 square miles of interior southeastern Massachusetts. The Taunton River basin is separated from the basins of short streams draining to the coast by low divides on the east, south, and southwest. On the west and north, the basin is bordered by the Ten Mile, Charles, Neponset, and Weymouth River basins. Principal tributaries of the lower Taunton River are Segreganset, Threemile, Mill, Assonet, Nemasket, and Winnetuxet Rivers. The upper part of the basin is drained by the Canoe, Wading, and Rumford Rivers which empty into Mill and Threemile Rivers and by the Matfield and Town Rivers which unite to form the Taunton River. This report presents in tabular form selected records of wells, test wells, and borings collected during a study of the basin from 1966 to 1968 in cooperation with the Massachusetts Water Resources Commission, and during earlier studies. This report is released in order to make available to the public and to local, state, and federal agencies basic ground-water information that may aid in planning water-resources development. Basic records contained in this report will complement an interpretative report on the Taunton River basin to be released at a later date.

Massachusetts↗
USGS1951

Preliminary report on the stratigraphy and structure of the Shaviovik and upper Sagavanirktok Rivers area, Alaska

During the 1951 field season, U. S. Geological Survey Navy Oil Unit party 1 conducted stratigraphic and structural studies of the rocks in the area between the westernmost fork of the Shaviovik River and the East Kuparuk River. This area is drained by the Sagavanirktok River and its major tributaries; the Echooka River, the Ivishak River, and Lupine River. Owing to the nature of the investigation, the studies were confined to a relatively narrow geographic strip, rarely exceeding a distance of 20 miles north of the northernmost occurrence of the Lisburne limestone of the Brooks Range province. The work was thus conducted in an area of approximately 2,000 square miles, which lies wholly within the Brooks and Arctic Foothill provinces; within this area approximately 1,000 square miles was mapped geologically. The party consisted of six men: A. S. Keller and R. L. Detterman, geologists; I. W. Marine and D. E. Reed, field assistants; L. G. Barbin, cook-field assistant; and T. F. Derrington, weasel mechanic. The party utilized 3 weasels for transportation of equipment and personnel during the season, during which time 15 camps ware established. Work was initiated on the Shaviovik River on May 24, 1951, and the party concluded its investigations on the Kuparuk River drainage on August 24, 1951. In 1947, G. Gryc and E. H. Lathram conducted reconnaissance studies of the rocks in the vicinity of camps 12-15 (pl. 1); and during the same year, G. Gryn visited outcrops on the Ivishak River in the vicinity of camps 6-7 (pl. 1). These studies were made by the Navy Oil Unit of the U. S. Geological Survey in conjunction with the investigations of NPR-4. No other work of a geologic nature had been done in the area in the past. The primary objective of the 1951 party was the correlation of the Mesozoic and upper Paleozoic strata of the foothills province west of the Itkillik River, with that of the Shaviovik and Canning Rivers region. A secondary objective was to determine the cause of the pronounced northeasterly swing in the trend of the Brooks Range front in the Sagavanirktok drainage and to determine the structural implications of this swing. The area was mapped at a scale of 1:20,000 on vertical photographs and transferred to trimetrogon drainage maps at a scale of 1:48,000 and 1:96, 00. An altimeter traverse was carried concurrently with the geologic mapping.

Alaska↗
USGS2011

Chloride control and monitoring program in the Wichita River Basin, Texas, 1996–2009

Water resources of the Wichita River Basin in north-central Texas are vital to the water users in Wichita Falls, Tex., and surrounding areas. The Wichita River Basin includes three major forks of the Wichita River upstream from Lake Kemp, approximately 50 miles southwest of Wichita Falls, Tex. The main stem of the Wichita River is formed by the confluence of the North Wichita River and Middle Fork Wichita River upstream from Truscott Brine Lake. The confluence of the South Wichita River with the Wichita River is northwest of Seymour, Tex. (fig. 1). Waters from the Wichita River Basin, which is part of the Red River Basin, are characterized by high concentrations of chloride and other salinity-related constituents from salt springs and seeps (hereinafter salt springs) in the upper reaches of the basin. These salt springs have their origins in the Permian Period when the Texas Panhandle and western Oklahoma areas were covered by a broad shallow sea. Over geologic time, evaporation of the shallow seas resulted in the formation of salt deposits, which today are part of the geologic formations underlying the area. Groundwater in these formations is characterized by high chloride concentrations from these salt deposits, and some of this groundwater is discharged by the salt springs into the Wichita River.

Texas↗
USGS2021

Tracking the source of metals to the San Juan River

Introduction The San Juan River is a major water source for communities in the Four Corners Region of the United States (Colorado, Arizona, New Mexico, Utah) and is a vital source of water for the Navajo Nation. The Navajo Nation Environmental Protection Agency (NNEPA) periodically samples surface water on the Navajo Nation and has found that some elements exceed NNEPA surface water standards (the upper limits of an element for consumption or other use of water). Constituents of concern are substances that could be harmful if present in sufficient quantities, and it is important to keep track of the concentrations of these substances in the environment. In the San Juan River, constituents of concern include metals detected in river water, such as arsenic, lead, and aluminum. These metals can come from natural sources or can result from human activities (anthropogenic) and can affect the health of people, plants, and animals. The Animas River is one natural source of metals to the San Juan River because of the types of rock through which the Animas River flows and because of hard rock mining at the headwaters. Other potential sources of metals are oil and gas development, coal mining, coal-fired power plants, urban areas, illegal trash dumping, abandoned uranium mines and mills, overgrazed areas, natural geology, and leaching from subsurface agricultural return flows. Determining how much each of these sources contributes and the relative effect of each source on San Juan River water will help the Navajo Nation in their efforts to protect human health and the environment along the San Juan River. The U.S. Geological Survey (USGS) is working with the NNEPA to identify sources of metals and trace elements entering the San Juan River from tributaries in the reach flowing through the Navajo Nation and to quantify the contribution from each natural and human-caused source. The USGS and NNEPA worked with local community members to locate tributaries where sampling equipment was installed. The 3-year source-tracking project, starting in spring 2021, will identify where metals at concentrations above safe surface water standards might be entering the river by evaluating the chemical signatures of water in the major tributaries of the San Juan River. Results will provide valuable information to the Navajo Nation, public drinking-water managers, irrigation districts, other stakeholders, scientists, and the public.

Colorado, Arizona, New Mexico, Utah↗
USGS1990

Geologic map and profiles of the north wall of the Snake River Canyon, Bliss, Hagerman, and Tuttle quadrangles, Idaho

The Snake River Plain is a broad, arcuate region of low relief that extends more than 300 mi across southern Idaho. The Snake River enters the plain near Idaho Falls and flows westward along the southern margin of the eastern Snake River Plain (fig. 1), a position mainly determined by the basaltic lava flows that erupted near the axis of the plain. The highly productive Snake River Plain aquifer north of the Snake River underlies most of the eastern plain. The aquifer is composed of basaltic rocks that are interbedded with fluvial and lacustrine sedimentary rocks. The top of the aquifer (water table) is typically less than 500 ft below the land surface, but is deeper than 1,000 ft in a few areas. The Snake River has excavated a canyon into the nearly flat-lying basaltic and sedimentary rocks of the eastern Snake River Plain between Milner Dam and King Hill (fig. 2), a distance of almost 90 mi. For much of its length the canyon wall as springs of variable size, spacing, and altitude. Geologic controls on springs are of importance because nearly 60 percent of the aquifer's discharge occurs as spring flow along this reach of the canyon. This report is one of several that describes the geologic occurrence of springs along the northern wall of the Snake River canyon from Milner Dam to King Hill (fig. 1). To understand the local geologic controls on springs, the Water Resources Division of the U.S. Geological Survey initiated a geologic mapping project as part of their Snake River Plain Regional Aquifer System-Analysis Program. Objectives of the project were (1) to prepare a geologic map of a strip of land immediately north of the Snake River canyon, (2) to map the geology of the north canyon wall in profile, (3) to locate spring occurrences along the north side of the Snake River between Milner Dam and King Hill, and (4) to estimate spring discharge from the north wall of the canyon.

Idaho↗
USGS2002

Travel times and dispersion of soluble dye in thirteen New Hampshire rivers

Dye was injected and traced in 13 New Hampshire rivers in 2000 to determine the velocity at which a soluble substance spilled into the river would travel to drinking-water supply intakes. Travel times were studied on the Ammonoosuc, Androscoggin, Connecticut, Contoocook, East Branch Pemigewasset, Exeter, Lamprey, Mascoma, Merrimack, Oyster, Piscassic, Salmon Falls, and Sugar Rivers. Dye was injected and sampled at low and mean flows, and the measured velocities extrapolated to provide an estimate of the velocity during a mean annual flood (mean of yearly peak flows for a specific river). Rivers were sampled downstream of the dye-injection sites to measure dye concentrations and the arrival and passage times of the dye cloud. This information was used to estimate a relation between river discharge and the expected dye concentrations and velocities for each river. Results of the dye tests were used to estimate a 6-hour travel distance at mean annual flood for each of the 13 rivers, and to create graphical relations that can be used to estimate the travel times and concentrations of solutes over a range of river discharges and distances. Observed transport velocities ranged from 0.03 to 2.4 feet per second, and the estimated 6-hour travel distances ranged from 5.8 to 43 miles. Rivers in upland areas had the highest velocities, whereas rivers in the low coastal region had the slowest velocities.

New Hampshire↗
USGS2009

Patterns of Larval Sucker Emigration from the Sprague and Lower Williamson Rivers of the Upper Klamath Basin, Oregon, Prior to the Removal of Chiloquin Dam - 2006 Annual Report

In 2006, we collected larval Lost River sucker Deltistes luxatus (LRS), shortnose sucker Chasmistes brevirostris (SNS), and Klamath largescale sucker Catostomus snyderi (KLS) emigrating from spawning areas in the Williamson and Sprague Rivers. This work is part of a multi-year effort to characterize the relative abundance, drift timing, and length frequencies of larval suckers in this watershed prior to the removal of Chiloquin Dam on the lower Sprague River. Additional larval drift samples were collected from the Fremont Bridge on Lakeshore Drive on the south end of Upper Klamath Lake near its outlet to the Link River. Because of difficulties in distinguishing KLS larvae from SNS larvae, individuals identified as either of these two species were grouped together and reported as KLS-SNS in this report. We found that larval densities varied by site with the highest densities being collected at the most upstream site on the Sprague River at river kilometer (rkm) 108.0 near Beatty, Oregon (Beatty), and the most downstream sites near Chiloquin, Oregon; one site on the Sprague River at rkm 0.7 (Chiloquin) and the other site on the Williamson River at rkm 7.4 (Williamson). Larval catches were relatively small and sporadic at two other sites on the Sprague River located between Chiloquin and Beatty (Power Station at rkm 9.5 and Lone Pine at rkm 52.7) and one site on the Sycan River at rkm 4.7. Most larvae (79 percent) collected in 2006 were identified as LRS. More larvae and eggs were collected at Chiloquin than at any other site. The seasonal timing of larval drift varied by location; larvae generally were captured earlier at upstream sites than at downstream sites. Cumulative catch percentages of drifting larvae suggest that larval LRS emigrated earlier than KLS-SNS larvae at every site. Drift of LRS larvae at Beatty began 3 to 4 weeks earlier than at Chiloquin or Williamson. At Chiloquin, peak larval catches occurred 3 and 5 weeks after peak egg catches. The daily peak in larval drift at Chiloquin occurred approximately 1.5 to 2.0 hours after sunset. Nightly peak larval drift varied by location; larvae were captured earlier in the evening at sites closer to known spawning locations than sites farther away from these areas. The highest numerical catches of sucker-sized eggs were at Chiloquin indicating that this site is in close proximity to a spawning area. Numerical catches of older, more developed larval and juvenile suckers also were highest at Chiloquin. This may be due to the turbulent nature of this site, which could have swept larger fish into the drift. Proportional catches of older, more developed larval and juvenile suckers were highest at Sycan, Lone Pine, Power Station, and Fremont Bridge. This indicates these sites are located nearer to sucker nursery areas rather than spawning areas. Very few larval LRS were collected at Fremont Bridge at the south end of Upper Klamath Lake. Larval KLS-SNS densities at Fremont Bridge were the third highest of the seven sampling sites. Peak drift of larval KLS-SNS at Fremont Bridge occurred the week after peak drift of larval KLS-SNS at Williamson. Although inter-annual variation continues to appear in the larval drift data, our results continue to show consistent patterns of larval emigration in the drainage basin. In combination with data collected from the spawning movements and destinations of radio-tagged and PIT-tagged adult suckers, this larval drift data will provide a baseline standard by which to determine the effects of dam removal on the spawning distribution of endangered Klamath Basin suckers in the Sprague River.

Open-File Report↗
USGS2009

Distribution and Joint Fish-Tag Survival of Juvenile Chinook Salmon Migrating through the Sacramento-San Joaquin River Delta, California, 2008

Acoustic telemetry was used to obtain the movement histories of 915 juvenile fall-run Chinook salmon (Oncorhynchus tshawytscha) through the lower San Joaquin River and Sacramento-San Joaquin Delta, California, in 2008. Data were analyzed within a release-recapture framework to estimate survival, route distribution, and detection probabilities among three migration pathways through the Delta. The pathways included the primary route through the San Joaquin River and two less direct routes (Old River and Turner Cut). Strong inferences about survival were limited by premature tag failure, but estimates of fish distribution among migration routes should be unaffected by tag failure. Based on tag failure tests (N = 66 tags), we estimated that only 55-78 percent of the tags used in this study were still functioning when the last fish was detected exiting the study area 15 days after release. Due to premature tag failure, our 'survival' estimates represent the joint probability that both the tag and fish survived, not just survival of fish. Low estimates of fish-tag survival could have been caused by fish mortality or fish travel times that exceeded the life of the tag, but we were unable to differentiate between the two. Fish-tag survival through the Delta (from Durham Ferry to Chipps Island by all routes) ranged from 0.05 +or- 0.01 (SE) to 0.06 +or- 0.01 between the two weekly release groups. Among the three migration routes, fish that remained in the San Joaquin River exhibited the highest joint fish-tag survival (0.09 +or- 0.02) in both weeks, but only 22-33 percent of tagged fish used this route, depending on the week of release. Only 4-10 percent (depending on week) of tagged fish traveled through Turner Cut, but no tagged fish that used this route were detected exiting the Delta. Most fish (63-68 percent, depending on week of release) migrated through Old River, but fish-tag survival through this route (0.05 +or- 0.01) was only about one-half that of fish that remained in the San Joaquin River. Once tagged fish entered Old River, only fish collected at two large water conveyance projects and transported through the Delta by truck were detected exiting the Delta, suggesting that this route was the only successful migration pathway for fish that entered Old River. The rate of entrainment of tagged juvenile salmon into Old River was similar to the fraction of San Joaquin River discharge flowing into Old River, which averaged 63 percent but varied tidally and ranged from 33 to 100 percent daily. Although improvements in transmitter battery life are clearly needed, this information will help guide the development of future research and monitoring efforts in this system.

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