Search USGS⌕ Search

SEARCH · Search USGS

Results for “River Systems”

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

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
USGS1995

A non-lethal measure of smolt status of juvenile steelhead based on body morphology

A nonlethal morphometric method to assess smolt status of juvenile steelhead Oncorhynchus mykiss was validated. Fish were collected from hatcheries before release and during their seaward migration in a large river system. Fifteen anatomical landmarks were digitized from photographs of each fish, resulting in 34 morphometric characters based on a truss network. Principal component and canonical discriminant function analyses were used to assess smolt status. A single canonical variate was significantly correlated with gill Na + ,K + ‐ATPase activity, a commonly used measure of smolt status. This nonlethal method may be a useful measure of smolt status when sacrificing fish is not desirable or possible; it requires little training to perform, but it does require a larger sample size than some other methods.

Transactions of the American Fisheries Society↗
USGS1998

Evaluation of generalized habitat criteria for assessing impacts of altered flow regimes on warmwater fishes

Assessing potential effects of flow regulation on southeastern warmwater fish assemblages is problematic because of high species richness and poor knowledge of habitat requirements for most species. Our study investigated relationships between availability and temporal persistence of key habitats and fish assemblage structure at regulated and unregulated sites in the Tallapoosa River system. Fish assemblage characteristics at seven sites were quantified based on 1,400 electrofishing samples collected during 1994 and 1995. Physical Habitat Simulation (PHABSIM) programs were used to model availability and persistence of key habitats at regulated and unregulated sites. Associations between fish assemblages and availability or persistence of key habitats were identified via regression and analysis of variance. We found that hydropeaking dam operation reduced the average length of time that shallow‐water habitats persisted and also reduced year‐to‐year variation in the persistence of shallow‐water habitats compared with unregulated sites. Across sites and years, proportional representation of catostomids was positively correlated with persistence of shallow and slow‐water habitats during spring. Proportion of individuals as cyprinids was positively correlated with median availability of deep–fast habitat whereas proportion of percids was inversely related to median availability of deep–fast habitat. Mean fish density was positively correlated with the persistence of shallow and slow‐water habitats. Comparisons of key‐habitat measures and fish abundances between 1994 and 1995 at each site indicated that higher abundances of percids, catostomids, and cyprinids were associated with increased availability and persistence of shallow and slow‐water habitats in 1995. These findings demonstrate that the temporal and spatial availability of key habitats could serve as useful measures of the potential effects of flow alteration on lotic fish assemblages and suggest that both short‐term persistence of key habitats as well as annual variation in key‐habitat availability are important for maintaining diverse fish assemblages.

Transactions of the American Fisheries Society↗
USGS1999

Rate of disappearance of gas bubble trauma signs in juvenile salmonids

To assess the rate of disappearance of gas bubble trauma (GBT) signs in juvenile salmonids, we exposed spring chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss to water containing high levels of dissolved gas supersaturation (DGS) for a time period sufficient to induce signs of GBT, reduced the DGS to minimal levels, and then sampled fish through time to document changes in severity of GBT. Because of the tendency of GBT signs to dissipate at different rates, we conducted trials focusing on emboli (bubbles) in the gill filaments and lateral line and separate trials that focused on bubbles in the external surfaces (fins, eyes, and opercula). Bubbles in gill filaments dissipated almost completely within 2 h after transfer of fish to water of nearly normal DGS (104%), whereas bubbles in the lateral line dissipated to negligible levels within 5 h. Bubbles on external surfaces were more persistent through time than they were in gill filaments and the lateral line. Although typically dissipating to low levels within 48 h, external bubbles sometimes remained for 4 d. Assuming a direct relation exists between easily observable signs and direct mortality, our results suggest that fish can recover quickly from the potentially lethal effects of DGS once they move from water with high DGS to water of almost normal gas saturation. These results should be of fundamental importance to fishery managers interpreting the results of monitoring for the severity and prevalence of GBT in juvenile salmonids in the Columbia River system and perhaps elsewhere.

Journal of Aquatic Animal Health↗
USGS2011

Factors affecting the occurrence of saugers in small, high-elevation rivers near the western edge of the species' natural distribution

Factors affecting the occurrence of saugers Sander canadensis were studied throughout the Wind River basin, a high-elevation watershed (> 1,440 m above mean sea level) on the western periphery of the species' natural distribution in central Wyoming. Adult saugers appeared to have a contiguous distribution over 170 km of streams among four rivers in the watershed. The upstream boundaries of sauger distribution were influenced by summer water temperatures and channel slopes in two rivers and by water diversion dams that created barriers to upstream movement in the other two rivers. Models that included summer water temperature, maximum water depth, habitat type (pool or run), dominant substrate, and alkalinity accounted for the variation in sauger occurrence across the watershed within the areas of sauger distribution. Water temperature was the most important basin-scale habitat feature associated with sauger occurrence, and maximum depth was the most important site-specific habitat feature. Saugers were found in a larger proportion of pools than runs in all segments of the watershed and occurred almost exclusively in pools in upstream segments of the watershed. Suitable summer water temperatures and deep, low-velocity habitat were available to support saugers over a large portion of the Wind River watershed. Future management of saugers in the Wind River watershed, as well as in other small river systems within the species' native range, should involve (1) preserving natural fluvial processes to maintain the summer water temperatures and physical habitat features needed by saugers and (2) assuring that barriers to movement do not reduce upstream boundaries of populations.

Transactions of the American Fisheries Society↗
USGS2007

Use of eyeballs for establishing ploidy of Asian carp

Grass carp Ctenopharyngodon idella, silver carp Hypophthalmichthys molitrix, and bighead carp H. nobilis are now established and relatively common in the Mississippi and Atchafalaya rivers. Commercial fishers of Louisiana's large rivers report recurrent catches of grass carp, and the frequency of bighead carp and silver carp catch is increasing. Twelve black carp Mylopharyngodon piceus were recently captured from the Mississippi and Atchafalaya River system, and 10 were analyzed for ploidy. By using the methods described herein, all 10 fish were determined to be diploid. Such correct identifications of ploidy of feral Asian carp species, as well as other species, would provide science-based information constructive for meeting reporting requirements, tracking fish movements, and forecasting expansion of species distribution. To investigate the postmortem period for sample collection and to lessen demands on field operations for obtaining samples, a laboratory study was performed to determine the length of time for which eyeballs from postmortem black carp could be used for ploidy determinations. Acquiring eyes rather than blood is simpler and quicker and requires no special supplies. An internal DNA reference standard with a documented genome size, including erythrocytes from diploid black carp or Nile tilapia Oreochromis niloticus, was analyzed simultaneously with cells from seven known triploid black carp to assess ploidy through 12 d after extraction. Ploidy determinations were reliable through 8 d postmortem. The field process entails excision of an eyeball, storage in a physiological buffer, and shipment within 8 d at refrigeration temperatures (4??C) to the laboratory for analysis by flow cytometry. ?? Copyright by the American Fisheries Society 2007.

North American Journal of Fisheries Management↗
USGS2014

Hybridization of two megacephalic map turtles (testudines: emydidae: Graptemys ) in the Choctawhatchee River drainage of Alabama and Florida

Map turtles of the genus Graptemys are highly aquatic and rarely undergo terrestrial movements, and limited dispersal among drainages has been hypothesized to drive drainage-specific endemism and high species richness of this group in the southeastern United States. Until recently, two members of the megacephalic “ pulchra clade,” Graptemys barbouri and Graptemys ernsti , were presumed to be allopatric with a gap in both species' ranges in the Choctawhatchee River drainage. In this paper, we analyzed variation in morphology (head and shell patterns) and genetics (mitochondrial DNA and microsatellite loci) from G. barbouri , G. ernsti , and Graptemys sp. collected from the Choctawhatchee River drainage, and we document the syntopic occurrence of those species and back-crossed individuals of mixed ancestry in the Choctawhatchee River drainage. Our results provide a first counter-example to the pattern of drainage-specific endemism in megacephalic Graptemys . Geologic events associated with Pliocene and Pleistocene sea level fluctuations and the existence of paleo-river systems appear to have allowed the invasion of the Choctawhatchee system by these species, and the subsequent introgression likely predates any potential human-mediated introduction.

Alabama, Florida↗
USGS2007

Effects of flow fluctuations on the spawning habitat of a riverine fish

Shallow-water, lithophilic spawning fishes are among the most vulnerable to anthropogenic fluctuations in water levels. We monitored water levels and environmental conditions at the nest sites of Moxostoma robustum (Robust Redhorse) on a main-channel gravel bar in the Savannah River, GA-SC During the course of the 2005 spawning season, over 50% of the observed nest sites were either completely dewatered or left in near zero-flow conditions for several days. This occurred on two separate occasions, once early during the spawning season and then again near its conclusion. We hypothesize the habitat preferences of spawning Robust Redhorse leave them vulnerable to water-level fluctuations, and this phenomenon may be widespread in regulated river systems.

Southeastern Naturalist↗
USGS2002

Evaluation of canoe surveys for anurans along the Rio Grande in Big Bend National Park, Texas

Surveys for amphibians along large rivers pose monitoring and sampling problems. We used canoes at night to spotlight and listen for anurans along four stretches of the Rio Grande in Big Bend National Park, Texas, in 1998 and 1999. We explored temporal and spatial variation in amphibian counts and species richness and assessed relationships between amphibian counts and environmental variables, as well as amphibian-habitat associations along the banks of the Rio Grande. We documented seven anuran species, but Rio Grande leopard frogs ( Rana berlandieri ) accounted for 96% of the visual counts. Chorus surveys along the river detected similar or fewer numbers of species, but orders of magnitude fewer individuals compared to visual surveys. The number of species varied on average by 37% across monthly and nightly surveys. We found similar average coefficients of variation in counts of Rio Grande leopard frogs on monthly and nightly bases (CVs = 42–44%), suggesting that canoe surveys are a fairly precise technique for counts of this species. Numbers of Rio Grande leopard frogs observed were influenced by river gage levels and air and water temperatures, suggesting that surveys should be conducted under certain environmental conditions to maximize counts and maintain consistency. We found significant differences in species richness and bullfrog ( Rana catesbeiana ) counts among the four river stretches. Four rare anuran species were found along certain stretches but not others, which could represent either sampling error or unmeasured environmental or habitat differences among the river stretches. We found a greater association of Rio Grande leopard frogs with mud banks compared to rock or cliff (canyon) areas and with seepwillow and open areas compared to giant reed and other vegetation types. Canoe surveys appear to be a useful survey technique for anurans along the Rio Grande and may work for other large river systems as well.

Texas↗
USGS1999

Reproductive biology and juvenile recruitment of the shinyrayed pocketbook, Lampsilis subangulata (Bivalvia: Unionidae) in the Gulf Coastal Plain

The reproductive biology, glochidial morphology and recruitment of the federally endangered shinyrayed pocketbook, Lampsilis subangulata , were studied from May 1995 to July 1996 in the Flint River system, Georgia. Gravid female L. subangulata were found nine months of the year. On 19 May 1995, a L. subangulata was discovered releasing a superconglutinate, the first record confirming that this species used this specialized reproductive strategy. Superconglutinate release occurred from late May to mid-July in water temperatures ranging from 20.0 to 23.5 C. Laboratory experiments indicated that two fish species served as primary hosts, the spotted bass ( Micropterus punctulatus ) and largemouth bass ( M. salmoides ). Secondary host fish included the eastern mosquitofish ( Gambusia holbrooki ), guppy ( Poecilia reticulata ) and bluegill ( Lepomis macrochirus ). The glochidial morphology of L. subangulata was similar to other lampsiline species. Using quantitative survey methods, no evidence of recent juvenile recruitment was found in the largest known extant L. subangulata population.

Georgia↗
USGS2014

Historic changes in fish assemblage structure in midwestern nonwadeable rivers

Historical change in fish assemblage structure was evaluated in the mainstems of the Des Moines, Iowa, Cedar, Wapsipinicon, and Maquoketa rivers, in Iowa. Fish occurrence data were compared in each river between historical and recent time periods to characterize temporal changes among 126 species distributions and assess spatiotemporal patterns in faunal similarity. A resampling procedure was used to estimate species occurrences in rivers during each assessment period and changes in species occurrence were summarized. Spatiotemporal shifts in species composition were analyzed at the river and river section scale using cluster analysis, pairwise Jaccard's dissimilarities, and analysis of multivariate beta dispersion. The majority of species exhibited either increases or declines in distribution in all rivers with the exception of several “unknown” or inconclusive trends exhibited by species in the Maquoketa River. Cluster analysis identified temporal patterns of similarity among fish assemblages in the Des Moines, Cedar, and Iowa rivers within the historical and recent assessment period indicating a significant change in species composition. Prominent declines of backwater species with phytophilic spawning strategies contributed to assemblage changes occurring across river systems.

Iowa↗
USGS2009

The Asian clam Corbicula fluminea as a biomonitor of trace element contamination: Accounting for different sources of variation using an hierarchical linear model

In the present study, specimens of the invasive clam, Corbicula fluminea, were collected above and below possible sources of potentially toxic trace elements (As, Cd, Cr, Cu, Hg, Pb, and Zn) in the Altamaha River system (Georgia, USA). Bioaccumulation of these elements was quantified, along with environmental (water and sediment) concentrations. Hierarchical linear models were used to account for variability in tissue concentrations related to environmental (site water chemistry and sediment characteristics) and individual (growth metrics) variables while identifying the strongest relations between these variables and trace element accumulation. The present study found significantly elevated concentrations of Cd, Cu, and Hg downstream of the outfall of kaolin-processing facilities, Zn downstream of a tire cording facility, and Cr downstream of both a nuclear power plant and a paper pulp mill. Models of the present study indicated that variation in trace element accumulation was linked to distance upstream from the estuary, dissolved oxygen, percentage of silt and clay in the sediment, elemental concentrations in sediment, shell length, and bivalve condition index. By explicitly modeling environmental variability, the Hierarchical linear modeling procedure allowed the identification of sites showing increased accumulation of trace elements that may have been caused by human activity. Hierarchical linear modeling is a useful tool for accounting for environmental and individual sources of variation in bioaccumulation studies. ?? 2009 SETAC.

Environmental Toxicology and Chemistry↗
USGS2014

A synoptic examination of causes of land loss in southern Louisiana as related to the exploitation of subsurface geologic resources

During the last 80 years, Louisiana has been losing wetlands at an average rate of 62 km 2 /y (24 mi 2 /y) for an accumulated loss of approximately 4900 km 2 (1900 mi 2 ). The loss seems to be the combined result of natural and anthropogenic causes that are behind primarily land subsidence averaging about 10 mm/y (0.4 in/y) coinciding with a sea level rise now at 3 mm/y (0.1 in/y), both contributing to coastal inundation. Upon completing extensive review of often controversial and conflicting views only synoptically reported here, conclusions reached by applying Monte Carlo simulation include: (1) geodetic measurements are consistent with independently postulated causes of regional subsidence; (2) ranking of subsidence factors shows that the main contributor to the regional subsidence is adjustment to sediment load in the form of lithosphere flexure followed by normal faulting dipping basinward, which combined, account on average for 70% of the subsidence, with compaction accounting for another 23%; and (3) production of oil and gas plays a tertiary role. The literature supports the historical view that before experiencing engineering modifications across the catchment area, sedimentation from the Mississippi River system was able to build a prograding coastline by overcoming subsidence rates of similar magnitude with more generous sediment loads of coarser particle size. Sea level rise will become an increasingly dominant factor in land loss only if the acceleration predicted by simulation model scenarios materializes. Wetland losses most likely will continue for as long as there is no compensation to counterbalance the negative effects of land subsidence and sea level rise, with the latter determining the pace of future losses.

Louisiana↗
USGS2000

Patterns of artificial nest depredation in a large floodplain forest

We used artificial bird nests to examine the relative effects of local habitat features and the surrounding landscape on the probability of songbird nest depredation in floodplain forests of the Upper Mississippi River. We found that the probability of depredation increased with size of floodplain forest plots. In small plots, the probability of depredation tended to increase away from the forest edge. Small patches of floodplain forest within a large river system can provide valuable nesting habitat for songbirds. We suggest that depredation pressure may be lower due to isolation effects. The probability of nest depredation increased with increasing canopy cover surrounding the nest tree and decreasing cover around the nest. Managers seeking to discourage nest predators in floodplain forests should consider managing for habitats that supply dense cover for nest concealment and an open tree canopy.

Iowa, Minnesota, Wisconsin↗
USGS1994

Major ions, nutrients, and trace elements in the Mississippi River near Thebes, Illinois, July through September 1993

Extensive flooding in the upper Mississippi River Basin during summer 1993 had a significant effect on the water quality of the Mississippi River. To evaluate the change in temporal distribution and transport of dissolved constituents in the Mississippi River, six water samples were collected by a discharge-weighted method from July through September 1993 near Thebes, Illinois. Sampling at this location provided water-quality information from the upper Mississippi, the Missouri, and the Illinois River Basins. Dissolved major constituents that were analyzed in each of the samples included bicarbonate, calcium (Ca), carbonate (C03), chloride (Cl), dissolved organic carbon, magnesium (Mg), potassium (K), silica NOD, sodium (Na), and sulfate (S04). Dissolved nutrients included ammonium ion (NH4), nitrate (N03), nitrite (N02), and orthophosphate (P04) . Dissolved trace elements included aluminum (Al), arsenic (As), barium (Ba), boron (B), beryllium (Be), bromide (Br), cadmium (Cd), chromium (Cr), cobalt, (Co), copper (Cu), fluoride (F), iron (Fe), lead, lithium (Li), manganese (Mn), mercury (Hg), molybdenum (Mo), nickel (Ni), strontium (Sr), thallium, uranium (U), vanadium (V), and zinc (Zn). Other physical properties of water that were measured included specific conductance, pH and suspended-sediment concentration (particle size, less than 63 micrometers). Results of this study indicated that large quantities of dissolved constituents were transported through the river system. Generally, pH, alkalinity, and specific conductance and the concentrations of B, Br, Ca, Cl, Cr, K, Li, Mg, Mo, Na, S04, Sr, U, and V increased as water discharge decreased, while concentrations of F, Hg, and suspended sediment sharply decreased as water discharge decreased after the crest of the flood. Concentrations of other constituents, such as Al, As, Ba, Be, Co, Cu, Ni, N03, N02, NH4, P04, and Si02, varied with time as discharge decreased after the crest of the flood. For most constituents, the load transported during floods generally is much greater than that transported during low-flow conditions. How ever, for Cd, Cr, Fe, Mn, V, and Zn, loads increased substantially as water discharge decreased after the crest of the flood.

Illinois↗
USGS2012

A synthesis of aquatic science for management of Lakes Mead and Mohave

Lakes Mead and Mohave, which are the centerpieces of Lake Mead National Recreation Area, provide many significant benefits that have made the modern development of the Southwestern United States possible. Lake Mead is the largest reservoir by volume in the nation and it supplies critical storage of water supplies for more than 25 million people in three Western States (California, Arizona, and Nevada). Storage within Lake Mead supplies drinking water and the hydropower to provide electricity for major cities including Las Vegas, Phoenix, Los Angeles, Tucson, and San Diego, and irrigation of more than 2.5 million acres of croplands. Lake Mead is arguably the most important reservoir in the nation because of its size and the services it delivers to the Western United States. This Circular includes seven chapters. Chapter 1 provides a short summary of the overall findings and management implications for Lakes Mead and Mohave that can be used to guide the reader through the rest of the Circular. Chapter 2 introduces the environmental setting and characteristics of Lakes Mead and Mohave and provides a brief management context of the lakes within the Colorado River system as well as overviews of the geological bedrock and sediment accumulations of the lakes. Chapter 3 contains summaries of the operational and hydrologic characteristics of Lakes Mead and Mohave. Chapter 4 provides information on water quality, including discussion on the monitoring of contaminants and sediments within the reservoirs. Chapter 5 describes aquatic biota and wildlife, including food-web dynamics, plankton, invertebrates, fish, aquatic birds, and aquatic vegetation. Chapter 6 outlines threats and stressors to the health of Lake Mead aquatic ecosystems that include a range of environmental contaminants, invasive species, and climate change. Chapter 7 provides a more detailed summary of overall findings that are presented in Chapter 1; and it contains a more detailed discussion on associated management implications, additional research, and monitoring needs.

Arizona, Nevada↗
USGS2017

Geochemistry of mercury and other constituents in subsurface sediment—Analyses from 2011 and 2012 coring campaigns, Cache Creek Settling Basin, Yolo County, California

Cache Creek Settling Basin was constructed in 1937 to trap sediment from Cache Creek before delivery to the Yolo Bypass, a flood conveyance for the Sacramento River system that is tributary to the Sacramento–San Joaquin Delta. Sediment management options being considered by stakeholders in the Cache Creek Settling Basin include sediment excavation; however, that could expose sediments containing elevated mercury concentrations from historical mercury mining in the watershed. In cooperation with the California Department of Water Resources, the U.S. Geological Survey undertook sediment coring campaigns in 2011–12 (1) to describe lateral and vertical distributions of mercury concentrations in deposits of sediment in the Cache Creek Settling Basin and (2) to improve constraint of estimates of the rate of sediment deposition in the basin. Sediment cores were collected in the Cache Creek Settling Basin, Yolo County, California, during October 2011 at 10 locations and during August 2012 at 5 other locations. Total core depths ranged from approximately 4.6 to 13.7 meters (15 to 45 feet), with penetration to about 9.1 meters (30 feet) at most locations. Unsplit cores were logged for two geophysical parameters (gamma bulk density and magnetic susceptibility); then, selected cores were split lengthwise. One half of each core was then photographed and archived, and the other half was subsampled. Initial subsamples from the cores (20-centimeter composite samples from five predetermined depths in each profile) were analyzed for total mercury, methylmercury, total reduced sulfur, iron speciation, organic content (as the percentage of weight loss on ignition), and grain-size distribution. Detailed follow-up subsampling (3-centimeter intervals) was done at six locations along an east-west transect in the southern part of the Cache Creek Settling Basin and at one location in the northern part of the basin for analyses of total mercury; organic content; and cesium-137, which was used for dating. This report documents site characteristics; field and laboratory methods; and results of the analyses of each core section and subsample of these sediment cores, including associated quality-assurance and quality-control data.

California↗
USGS2000

Volumes of recent floods and potential for storage in upland watershed areas of Iowa

Substantial flooding at various locations throughout the United States, particularly during and after the Upper Mississippi River Basin flood of 1993, has resulted in analysis and discussion of both structural and nonstructural methods of watershed management to control flooding. The Upper Mississippi River Basin flood of 1993 resulted in the formulation of a Scientific Assessment and Strategy Team (SAST) to assist and advise decision makers about the positive and negative effects of flood-control measures and habitat restoration (Scientific Assessment and Strategy Team, 1994). SAST recognized the role of upland processes and the interconnectivity of a management strategy on other parts of the river system. If upland areas are considered for inclusion in an overall management strategy related to flooding, an analysis of watershed that have been flooded and the amount of runoff generated during those floods is needed. During the autumn of 1997, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, began a study to determine the volume of water associated with recent flood events in parts of the Midwestern United States and a preliminary evaluation of the potential upland areas for storage of flood-waters in selected watersheds. This analysis, although preliminary, may be useful in determining the feasibility of conducting additional, more detailed studies into the role of upland areas in a watershed management strategy. The methods and results of this preliminary hydrologic study are presented in this report.

Iowa↗
USGS2003

The Flood of June 2003 in Southwest Central Florida

A series of severe thunderstorms brought heavy rainfall and flooding to southwest-central Florida during June 21-24, 2003. The storms and resultant precipitation were caused by a late-season stationary cool front (Canadian high pressure ridge) that combined with tropical moisture from the Gulf of Mexico to produce above-normal rainfall over already saturated ground (National Weather Service, written commun., 2003). Rainfall totals at U.S. Geological Survey (USGS) streamflow-gaging stations ranged from 9 to 17 inches and record flooding occurred in parts of Charlotte, De Soto, Hardee, Manatee, and Sarasota Counties, Florida (fig. 1). The floods caused $11.3 million in damage to public and private property, including damage or destruction of 119 homes (Binette and Saewitz, 2003). Western De Soto, western Hardee, Manatee, and Sarasota Counties are drained by the Horse Creek, Manatee River, and Myakka River systems. Water in these watersheds flows southwestward to Charlotte Harbor and the Gulf of Mexico (fig. 1).

Fact Sheet↗