The ability of natural attenuation to mitigate agricultural nitrate contamination in recharging aquifers was investigated in four important agricultural settings in the United States. The study used laboratory analyses, field measurements, and flow and transport modeling for monitoring well transects (0.5 to 2.5 km in length) in the San Joaquin watershed, California, the Elkhorn watershed, Nebraska, the Yakima watershed, Washington, and the Chester watershed, Maryland. Ground water analyses included major ion chemistry, dissolved gases, nitrogen and oxygen stable isotopes, and estimates of recharge date. Sediment analyses included potential electron donors and stable nitrogen and carbon isotopes. Within each site and among aquifer-based medians, dissolved oxygen decreases with ground water age, and excess N2 from denitrification increases with age. Stable isotopes and excess N2 imply minimal denitrifying activity at the Maryland and Washington sites, partial denitrification at the California site, and total denitrification across portions of the Nebraska site. At all sites, recharging electron donor concentrations are not sufficient to account for the losses of dissolved oxygen and nitrate, implying that relict, solid phase electron donors drive redox reactions. Zero-order rates of denitrification range from 0 to 0.14 μmol N L−1d−1, comparable to observations of other studies using the same methods. Many values reported in the literature are, however, orders of magnitude higher, which is attributed to a combination of method limitations and bias for selection of sites with rapid denitrification. In the shallow aquifers below these agricultural fields, denitrification is limited in extent and will require residence times of decades or longer to mitigate modern nitrate contamination.
","language":"English","publisher":"ACSESS","doi":"10.2134/jeq2006.0419","issn":"00472425","usgsCitation":"Green, C., Puckett, L., Böhlke, J., Bekins, B., Phillips, S., Kauffman, L.J., Denver, J.M., and Johnson, H., 2008, Limited occurrence of denitrification in four shallow aquifers in agricultural areas of the United States: Journal of Environmental Quality, v. 37, no. 3, p. 994-1009, https://doi.org/10.2134/jeq2006.0419.","productDescription":"16 p.","startPage":"994","endPage":"1009","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true},{"id":470,"text":"New Jersey Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242623,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"37","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4791e4b0c8380cd678d5","contributors":{"authors":[{"text":"Green, C.T.","contributorId":73785,"corporation":false,"usgs":true,"family":"Green","given":"C.T.","email":"","affiliations":[],"preferred":false,"id":433620,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Puckett, L.J.","contributorId":27503,"corporation":false,"usgs":true,"family":"Puckett","given":"L.J.","email":"","affiliations":[],"preferred":false,"id":433617,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Böhlke, J.K. 0000-0001-5693-6455","orcid":"https://orcid.org/0000-0001-5693-6455","contributorId":96696,"corporation":false,"usgs":true,"family":"Böhlke","given":"J.K.","affiliations":[],"preferred":false,"id":433622,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Bekins, B.A.","contributorId":98309,"corporation":false,"usgs":true,"family":"Bekins","given":"B.A.","email":"","affiliations":[],"preferred":false,"id":433623,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Phillips, S.P.","contributorId":38172,"corporation":false,"usgs":true,"family":"Phillips","given":"S.P.","email":"","affiliations":[],"preferred":false,"id":433618,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Kauffman, L. J. 0000-0003-4564-0362","orcid":"https://orcid.org/0000-0003-4564-0362","contributorId":65217,"corporation":false,"usgs":true,"family":"Kauffman","given":"L.","email":"","middleInitial":"J.","affiliations":[{"id":470,"text":"New Jersey Water Science Center","active":true,"usgs":true}],"preferred":false,"id":433619,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Denver, J. M.","contributorId":100356,"corporation":false,"usgs":true,"family":"Denver","given":"J.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":433624,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Johnson, H.M. 0000-0002-7571-4994","orcid":"https://orcid.org/0000-0002-7571-4994","contributorId":75339,"corporation":false,"usgs":true,"family":"Johnson","given":"H.M.","affiliations":[],"preferred":false,"id":433621,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70031893,"text":"70031893 - 2008 - Using HEM surveys to evaluate disposal of by-product water from CBNG development in the Powder River Basin, Wyoming","interactions":[],"lastModifiedDate":"2012-03-12T17:21:26","indexId":"70031893","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1808,"text":"Geophysics","active":true,"publicationSubtype":{"id":10}},"title":"Using HEM surveys to evaluate disposal of by-product water from CBNG development in the Powder River Basin, Wyoming","docAbstract":"Production of methane from thick, extensive coal beds in the Powder River Basin of Wyoming has created water management issues. Since development began in 1997, more than 650 billion liters of water have been produced from approximately 22,000 wells. Infiltration impoundments are used widely to dispose of by-product water from coal bed natural gas (CBNG) production, but their hydrogeologic effects are poorly understood. Helicopter electromagnetic surveys (HEM) were completed in July 2003 and July 2004 to characterize the hydrogeology of an alluvial aquifer along the Powder River. The aquifer is receiving CBNG produced water discharge from infiltration impoundments. HEM data were subjected to Occam's inversion algorithms to determine the aquifer bulk conductivity, which was then correlated towater salinity using site-specific sampling results. The HEM data provided high-resolution images of salinity levels in the aquifer, a result not attainable using traditional sampling methods. Interpretation of these images reveals clearly the produced water influence on aquifer water quality. Potential shortfalls to this method occur where there is no significant contrast in aquifer salinity and infiltrating produced water salinity and where there might be significant changes in aquifer lithology. Despite these limitations, airborne geophysical methods can provide a broadscale (watershed-scale) tool to evaluate CBNG water disposal, especially in areas where field-based investigations are logistically prohibitive. This research has implications for design and location strategies of future CBNG water surface disposal facilities within the Powder River Basin. ?? 2008 2008 Society of ExplorationGeophysicists. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geophysics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1190/1.2901200","issn":"00168033","usgsCitation":"Lipinski, B., Sams, J., Smith, B.D., and Harbert, W., 2008, Using HEM surveys to evaluate disposal of by-product water from CBNG development in the Powder River Basin, Wyoming: Geophysics, v. 73, no. 3, https://doi.org/10.1190/1.2901200.","costCenters":[],"links":[{"id":214839,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1190/1.2901200"},{"id":242591,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"73","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc012e4b08c986b329ef0","contributors":{"authors":[{"text":"Lipinski, B.A.","contributorId":53185,"corporation":false,"usgs":true,"family":"Lipinski","given":"B.A.","email":"","affiliations":[],"preferred":false,"id":433614,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sams, J.I.","contributorId":76903,"corporation":false,"usgs":true,"family":"Sams","given":"J.I.","email":"","affiliations":[],"preferred":false,"id":433616,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Smith, B. D.","contributorId":71123,"corporation":false,"usgs":true,"family":"Smith","given":"B.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":433615,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Harbert, W.","contributorId":28441,"corporation":false,"usgs":true,"family":"Harbert","given":"W.","email":"","affiliations":[],"preferred":false,"id":433613,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70033252,"text":"70033252 - 2008 - Determination of dominant biogeochemical processes in a contaminated aquifer-wetland system using multivariate statistical analysis","interactions":[],"lastModifiedDate":"2018-10-22T09:12:46","indexId":"70033252","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2262,"text":"Journal of Environmental Quality","active":true,"publicationSubtype":{"id":10}},"title":"Determination of dominant biogeochemical processes in a contaminated aquifer-wetland system using multivariate statistical analysis","docAbstract":"Determining the processes governing aqueous biogeochemistry in a wetland hydrologically linked to an underlying contaminated aquifer is challenging due to the complex exchange between the systems and their distinct responses to changes in precipitation, recharge, and biological activities. To evaluate temporal and spatial processes in the wetland-aquifer system, water samples were collected using cm-scale multi-chambered passive diffusion samplers (peepers) to span the wetland-aquifer interface over a period of 3 yr. Samples were analyzed for major cations and anions, methane, and a suite of organic acids resulting in a large dataset of over 8000 points, which was evaluated using multivariate statistics. Principal component analysis (PCA) was chosen with the purpose of exploring the sources of variation in the dataset to expose related variables and provide insight into the biogeochemical processes that control the water chemistry of the system. Factor scores computed from PCA were mapped by date and depth. Patterns observed suggest that (i) fermentation is the process controlling the greatest variability in the dataset and it peaks in May; (ii) iron and sulfate reduction were the dominant terminal electron-accepting processes in the system and were associated with fermentation but had more complex seasonal variability than fermentation; (iii) methanogenesis was also important and associated with bacterial utilization of minerals as a source of electron acceptors (e.g., barite BaSO4); and (iv) seasonal hydrological patterns (wet and dry periods) control the availability of electron acceptors through the reoxidation of reduced iron-sulfur species enhancing iron and sulfate reduction.
","language":"English","publisher":"ACSESS","doi":"10.2134/jeq2007.0169","issn":"00472425","usgsCitation":"Baez-Cazull, S.E., McGuire, J., Cozzarelli, I., and Voytek, M., 2008, Determination of dominant biogeochemical processes in a contaminated aquifer-wetland system using multivariate statistical analysis: Journal of Environmental Quality, v. 37, no. 1, p. 30-46, https://doi.org/10.2134/jeq2007.0169.","productDescription":"17 p.","startPage":"30","endPage":"46","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240725,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213132,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2134/jeq2007.0169"}],"volume":"37","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ffa2e4b0c8380cd4f2ce","contributors":{"authors":[{"text":"Baez-Cazull, S. E.","contributorId":64034,"corporation":false,"usgs":true,"family":"Baez-Cazull","given":"S.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":440030,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McGuire, J.T.","contributorId":17023,"corporation":false,"usgs":true,"family":"McGuire","given":"J.T.","email":"","affiliations":[],"preferred":false,"id":440027,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Cozzarelli, I.M. 0000-0002-5123-1007","orcid":"https://orcid.org/0000-0002-5123-1007","contributorId":22343,"corporation":false,"usgs":true,"family":"Cozzarelli","given":"I.M.","affiliations":[],"preferred":false,"id":440028,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Voytek, M.A.","contributorId":44272,"corporation":false,"usgs":true,"family":"Voytek","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":440029,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70033254,"text":"70033254 - 2008 - A basin-scale approach to estimating stream temperatures of tributaries to the lower Klamath River, California","interactions":[],"lastModifiedDate":"2018-09-18T09:17:43","indexId":"70033254","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2262,"text":"Journal of Environmental Quality","active":true,"publicationSubtype":{"id":10}},"title":"A basin-scale approach to estimating stream temperatures of tributaries to the lower Klamath River, California","docAbstract":"Stream temperature is an important component of salmonid habitat and is often above levels suitable for fish survival in the Lower Klamath River in northern California. The objective of this study was to provide boundary conditions for models that are assessing stream temperature on the main stem for the purpose of developing strategies to manage stream conditions using Total Maximum Daily Loads. For model input, hourly stream temperatures for 36 tributaries were estimated for 1 Jan. 2001 through 31 Oct. 2004. A basin-scale approach incorporating spatially distributed energy balance data was used to estimate the stream temperatures with measured air temperature and relative humidity data and simulated solar radiation, including topographic shading and corrections for cloudiness. Regression models were developed on the basis of available stream temperature data to predict temperatures for unmeasured periods of time and for unmeasured streams. The most significant factor in matching measured minimum and maximum stream temperatures was the seasonality of the estimate. Adding minimum and maximum air temperature to the regression model improved the estimate, and air temperature data over the region are available and easily distributed spatially. The addition of simulated solar radiation and vapor saturation deficit to the regression model significantly improved predictions of maximum stream temperature but was not required to predict minimum stream temperature. The average SE in estimated maximum daily stream temperature for the individual basins was 0.9 ?? 0.6??C at the 95% confidence interval. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Environmental Quality","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2134/jeq2006.0341","issn":"00472425","usgsCitation":"Flint, L.E., and Flint, A.L., 2008, A basin-scale approach to estimating stream temperatures of tributaries to the lower Klamath River, California: Journal of Environmental Quality, v. 37, no. 1, p. 57-68, https://doi.org/10.2134/jeq2006.0341.","startPage":"57","endPage":"68","numberOfPages":"12","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":240759,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213162,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2134/jeq2006.0341"}],"volume":"37","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e318e4b0c8380cd45e0a","contributors":{"authors":[{"text":"Flint, L. E. 0000-0002-7868-441X","orcid":"https://orcid.org/0000-0002-7868-441X","contributorId":38180,"corporation":false,"usgs":true,"family":"Flint","given":"L.","middleInitial":"E.","affiliations":[],"preferred":false,"id":440033,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Flint, A. L.","contributorId":102453,"corporation":false,"usgs":true,"family":"Flint","given":"A.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":440034,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70033257,"text":"70033257 - 2008 - A multi-residue method for the analysis of pesticides and pesticide degradates in water using HLB solid-phase extraction and gas chromatography-ion trap mass spectrometry","interactions":[],"lastModifiedDate":"2018-10-22T08:12:33","indexId":"70033257","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1103,"text":"Bulletin of Environmental Contamination and Toxicology","active":true,"publicationSubtype":{"id":10}},"title":"A multi-residue method for the analysis of pesticides and pesticide degradates in water using HLB solid-phase extraction and gas chromatography-ion trap mass spectrometry","docAbstract":"A method was developed for the analysis of over 60 pesticides and degradates in water by HLB solid-phase extraction and gas-chromatography/mass spectrometry. Method recoveries and detection limits were determined using two surface waters with different dissolved organic carbon (DOC) concentrations. In the lower DOC water, recoveries and detection limits were 80%–108% and 1–12 ng/L, respectively. In the higher DOC water, the detection limits were slightly higher (1–15 ng/L). Additionally, surface water samples from four sites were analyzed and 14 pesticides were detected with concentrations ranging from 4 to 1,200 ng/L.
Manipulations of the vegetation and hydrology of wetlands for mosquito control are common worldwide, but these modifications may affect vital ecosystem processes. To control mosquitoes in mangrove swamps in eastern Florida, managers have used rotational impoundment management (RIM) as an alternative to the worldwide practice of mosquito ditching. Levees surround RIM swamps, and water is pumped into the impoundment during the summer, a season when natural swamps have low water levels. In the New World, these mosquito-managed swamps resemble the mixed basin type of mangrove swamp (based on PCA analysis). An assessment was made of RIM, natural (control), and breached-RIM (restored) swamps in eastern Florida to compare their structural complexities, soil development, and resistance to invasion. Regarding structural complexity, dominant species composition differed between these swamps; the red mangrove Rhizophora mangle occurred at a higher relative density in RIM and breached-RIM swamps, and the black mangrove Avicennia germinans had a higher relative density in natural swamps. Tree density and canopy cover were higher and tree height lower in RIM swamps than in natural and breached-RIM swamps. Soil organic matter in RIM swamps was twice that in natural or breached-RIM swamps. RIM swamps had a lower resistance to invasion by the Brazilian pepper tree Schinus terebinthifolius, which is likely attributable to the lower porewater salinity in RIM swamps. These characteristics may reflect differences in important ecosystem processes (primary production, trophic structure, nutrient cycling, decomposition). Comparative assessments of managed wetlands are vital for land managers, so that they can make informed decisions compatible with conservation objectives.
","language":"English","doi":"10.3354/meps07683","issn":"01718","usgsCitation":"Middleton, B., Devlin, D., Proffitt, E., McKee, K., and Cretini, K., 2008, Characteristics of mangrove swamps managed for mosquito control in eastern Florida, USA: Marine Ecology Progress Series, v. 371, p. 117-129, https://doi.org/10.3354/meps07683.","productDescription":"13 p.","startPage":"117","endPage":"129","numberOfPages":"13","costCenters":[],"links":[{"id":476800,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.3354/meps07683","text":"Publisher Index Page"},{"id":240977,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Florida","volume":"371","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f49be4b0c8380cd4bdfb","contributors":{"authors":[{"text":"Middleton, B. 0000-0002-1220-2326","orcid":"https://orcid.org/0000-0002-1220-2326","contributorId":29939,"corporation":false,"usgs":true,"family":"Middleton","given":"B.","affiliations":[{"id":17705,"text":"Wetland and Aquatic Research Center","active":true,"usgs":true}],"preferred":false,"id":439047,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Devlin, D.","contributorId":22156,"corporation":false,"usgs":true,"family":"Devlin","given":"D.","email":"","affiliations":[],"preferred":false,"id":439046,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Proffitt, E.","contributorId":36758,"corporation":false,"usgs":true,"family":"Proffitt","given":"E.","email":"","affiliations":[],"preferred":false,"id":439048,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"McKee, Karen 0000-0001-7042-670X","orcid":"https://orcid.org/0000-0001-7042-670X","contributorId":69273,"corporation":false,"usgs":true,"family":"McKee","given":"Karen","affiliations":[{"id":17705,"text":"Wetland and Aquatic Research Center","active":true,"usgs":true}],"preferred":false,"id":439050,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Cretini, K.F. 0000-0003-0419-0748","orcid":"https://orcid.org/0000-0003-0419-0748","contributorId":55922,"corporation":false,"usgs":true,"family":"Cretini","given":"K.F.","affiliations":[],"preferred":false,"id":439049,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70031887,"text":"70031887 - 2008 - In situ estimation of the effective chemical diffusion coefficient of a rock matrix in a fractured aquifer","interactions":[],"lastModifiedDate":"2020-07-17T19:26:25.312435","indexId":"70031887","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1923,"text":"Hydrogeology Journal","active":true,"publicationSubtype":{"id":10}},"title":"In situ estimation of the effective chemical diffusion coefficient of a rock matrix in a fractured aquifer","docAbstract":"An in situ method of estimating the effective diffusion coefficient for a chemical constituent that diffuses into the primary porosity of a rock is developed by abruptly changing the concentration of the dissolved constituent in a borehole in contact with the rock matrix and monitoring the time-varying concentration. The experiment was conducted in a borehole completed in mudstone on the campus of the University of the Free State in Bloemfontein, South Africa. Numerous tracer tests were conducted at this site, which left a residual concentration of sodium chloride in boreholes that diffused into the rock matrix over a period of years. Fresh water was introduced into a borehole in contact with the mudstone, and the time-varying increase of chloride was observed by monitoring the electrical conductivity (EC) at various depths in the borehole. Estimates of the effective diffusion coefficient were obtained by interpreting measurements of EC over 34 d. The effective diffusion coefficient at a depth of 36 m was approximately 7.8×10−6 m2/d, but was sensitive to the assumed matrix porosity. The formation factor and mass flux for the mudstone were also estimated from the experiment.
","language":"English","publisher":"Springer","doi":"10.1007/s10040-007-0255-0","issn":"14312174","usgsCitation":"Gebrekristos, R., Shapiro, A., and Usher, B., 2008, In situ estimation of the effective chemical diffusion coefficient of a rock matrix in a fractured aquifer: Hydrogeology Journal, v. 16, no. 4, p. 629-639, https://doi.org/10.1007/s10040-007-0255-0.","productDescription":"11 p.","startPage":"629","endPage":"639","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":242521,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"South Africa","city":"Bloemfontein","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n 26.03759765625,\n -29.288794393648296\n ],\n [\n 26.42486572265625,\n -29.288794393648296\n ],\n [\n 26.42486572265625,\n -28.969700808694157\n ],\n [\n 26.03759765625,\n -28.969700808694157\n ],\n [\n 26.03759765625,\n -29.288794393648296\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"16","issue":"4","noUsgsAuthors":false,"publicationDate":"2008-01-15","publicationStatus":"PW","scienceBaseUri":"505a399fe4b0c8380cd619a7","contributors":{"authors":[{"text":"Gebrekristos, R.A.","contributorId":25830,"corporation":false,"usgs":true,"family":"Gebrekristos","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":433593,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Shapiro, A.M. 0000-0002-6425-9607","orcid":"https://orcid.org/0000-0002-6425-9607","contributorId":88384,"corporation":false,"usgs":true,"family":"Shapiro","given":"A.M.","affiliations":[],"preferred":true,"id":433595,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Usher, B.H.","contributorId":81763,"corporation":false,"usgs":true,"family":"Usher","given":"B.H.","email":"","affiliations":[],"preferred":false,"id":433594,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70032109,"text":"70032109 - 2008 - A rapid method for hydraulic profiling in unconsolidated formations","interactions":[],"lastModifiedDate":"2012-03-12T17:21:55","indexId":"70032109","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1861,"text":"Ground Water","active":true,"publicationSubtype":{"id":10}},"title":"A rapid method for hydraulic profiling in unconsolidated formations","docAbstract":"Information on vertical variations in hydraulic conductivity (K) can often shed much light on how a contaminant will move in the subsurface. The direct-push injection logger has been developed to rapidly obtain such information in shallow unconsolidated settings. This small-diameter tool consists of a short screen located just behind a drive point. The tool is advanced into the subsurface while water is injected through the screen to keep it clear. Upon reaching a depth at which information about K is desired, advancement ceases and the injection rate and pressure are measured on the land surface. The rate and pressure values are used in a ratio that serves as a proxy for K. A vertical profile of this ratio can be transformed into a K profile through regressions with K estimates determined using other techniques. The viability of the approach was assessed at an extensively studied field site in eastern Germany. The assessment demonstrated that this tool can rapidly identify zones that may serve as conduits for or barriers to contaminant movement. ?? 2007 The Author(s).","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ground Water","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1745-6584.2007.00377.x","issn":"0017467X","usgsCitation":"Dietrich, P., Butler, J., and Faiss, K., 2008, A rapid method for hydraulic profiling in unconsolidated formations: Ground Water, v. 46, no. 2, p. 323-328, https://doi.org/10.1111/j.1745-6584.2007.00377.x.","startPage":"323","endPage":"328","numberOfPages":"6","costCenters":[],"links":[{"id":476784,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1111/j.1745-6584.2007.00377.x","text":"Publisher Index Page"},{"id":215060,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1745-6584.2007.00377.x"},{"id":242829,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"46","issue":"2","noUsgsAuthors":false,"publicationDate":"2007-10-30","publicationStatus":"PW","scienceBaseUri":"5059e52ce4b0c8380cd46bac","contributors":{"authors":[{"text":"Dietrich, P.","contributorId":80074,"corporation":false,"usgs":true,"family":"Dietrich","given":"P.","email":"","affiliations":[],"preferred":false,"id":434582,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Butler, J.J. Jr.","contributorId":12194,"corporation":false,"usgs":true,"family":"Butler","given":"J.J.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":434580,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Faiss, K.","contributorId":53617,"corporation":false,"usgs":true,"family":"Faiss","given":"K.","email":"","affiliations":[],"preferred":false,"id":434581,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033259,"text":"70033259 - 2008 - Fall diets of red-breasted merganser (Mergus serrator) and walleye (Sander vitreus) in Sandusky Bay and adjacent waters of western Lake Erie","interactions":[],"lastModifiedDate":"2012-03-12T17:21:35","indexId":"70033259","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":737,"text":"American Midland Naturalist","active":true,"publicationSubtype":{"id":10}},"title":"Fall diets of red-breasted merganser (Mergus serrator) and walleye (Sander vitreus) in Sandusky Bay and adjacent waters of western Lake Erie","docAbstract":"Although published studies indicate the contrary, there is concern among many sport anglers that migrating red-breasted mergansers (Mergus serrator) and other waterbirds pose a competitive threat to sport fish species such as walleye (Sander vitreus) in Lake Erie. We quantified the diet of autumn-migrant mergansers and walleye during 1998-2000 in Sandusky Bay and adjacent waters of western Lake Erie. We hypothesized that the diets of both predators would be similar in species composition, but because of different foraging ecologies their diets would differ markedly in size of prey consumed. In addition to predator samples, we used trawl data from the same general area as an index of prey availability. We found that mergansers fed almost exclusively on fish (nine species). Gizzard shad (Dorosoma cepedianum), emerald shiner (Notropis atherinoides) and round goby (Neogobius melanostomus) were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Walleye fed exclusively on fish: gizzard shad, alewife (Alosa psuedoharengus) and emerald shiner were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Diet overlap between mergansers and walleye was 67% by weight and 66% by species frequency. Mean total lengths of gizzard shad, emerald shiner and round goby found in walleye stomachs exceeded those captured in trawls by 47%, on average. Mean total lengths of gizzard shad, emerald shiner and round goby were greater in walleye stomachs than in merganser stomachs. Mean total lengths of emerald shiner and round goby were less in merganser stomachs than in trawls. Our results suggest that although the diets of walleye and mergansers overlapped considerably, mergansers generally consumed smaller fish than walleye. Given the abundance and diversity of prey species available, and the transient nature of mergansers on Lake Erie during migration, we conclude that competition for food between these species is minimal.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"American Midland Naturalist","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1674/0003-0031(2008)159[147:FDORMM]2.0.CO;2","issn":"00030031","usgsCitation":"Bur, M., Stapanian, M., Bernhardt, G., and Turner, M., 2008, Fall diets of red-breasted merganser (Mergus serrator) and walleye (Sander vitreus) in Sandusky Bay and adjacent waters of western Lake Erie: American Midland Naturalist, v. 159, no. 1, p. 147-161, https://doi.org/10.1674/0003-0031(2008)159[147:FDORMM]2.0.CO;2.","startPage":"147","endPage":"161","numberOfPages":"15","costCenters":[],"links":[{"id":213220,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1674/0003-0031(2008)159[147:FDORMM]2.0.CO;2"},{"id":240824,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"159","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0ee5e4b0c8380cd53693","contributors":{"authors":[{"text":"Bur, M.T.","contributorId":58215,"corporation":false,"usgs":true,"family":"Bur","given":"M.T.","email":"","affiliations":[],"preferred":false,"id":440049,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stapanian, M.A.","contributorId":65437,"corporation":false,"usgs":true,"family":"Stapanian","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":440050,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bernhardt, G.","contributorId":48837,"corporation":false,"usgs":true,"family":"Bernhardt","given":"G.","email":"","affiliations":[],"preferred":false,"id":440048,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Turner, M.W.","contributorId":25424,"corporation":false,"usgs":true,"family":"Turner","given":"M.W.","email":"","affiliations":[],"preferred":false,"id":440047,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70033265,"text":"70033265 - 2008 - The A and m coefficients in the Bruun/Dean equilibrium profile equation seen from the Arctic","interactions":[],"lastModifiedDate":"2012-03-12T17:21:35","indexId":"70033265","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2220,"text":"Journal of Coastal Research","active":true,"publicationSubtype":{"id":10}},"title":"The A and m coefficients in the Bruun/Dean equilibrium profile equation seen from the Arctic","docAbstract":"The Bruun/Dean relation between water depth and distance from the shore with a constant profile shape factor is widely used to describe shoreface profiles in temperate environments. However, it has been shown that the sediment scale parameter (A) and the profile shape factor (m) are interrelated variables. An analysis of 63 Arctic erosional shoreface profiles shows that both coefficients are highly variable. Relative frequency of the average m value is only 16% by the class width 0.1. No other m value frequency exceeds 21%. Therefore, there is insufficient reason to use average m to characterize Arctic shoreface profile shape. The shape of each profile has a definite combination of A and m values. Coefficients A and m show a distinct inverse relationship, as in temperate climate. A dependence of m values on coastal sediment grain size is seen, and m decreases with increasing grain size. With constant m = 0.67, parameter A obtains a dimension unit m1/3. But A equals the water depth in meters 1 m from the water edge. This fact and the variability of parameter m testify that the Bruun/Dean equation is essentially an empirical formula. There is no need to give any measurement unit to parameter A. But the International System of Units (SI) has to be used in applying the Bruun/Dean equation for shoreface profiles. A comparison of the shape of Arctic shoreface profiles with those of temperate environments shows surprising similarity. Therefore, the conclusions reached in this Arctic paper seem to apply also to temperate environments.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Coastal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2112/05-0572.1","issn":"07490208","usgsCitation":"Are, F., and Reimnitz, E., 2008, The A and m coefficients in the Bruun/Dean equilibrium profile equation seen from the Arctic: Journal of Coastal Research, v. 24, no. 2 SUPPL. B, p. 243-249, https://doi.org/10.2112/05-0572.1.","startPage":"243","endPage":"249","numberOfPages":"7","costCenters":[],"links":[{"id":213313,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2112/05-0572.1"},{"id":240925,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"24","issue":"2 SUPPL. B","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505ba65be4b08c986b32109d","contributors":{"authors":[{"text":"Are, F.","contributorId":46772,"corporation":false,"usgs":true,"family":"Are","given":"F.","affiliations":[],"preferred":false,"id":440069,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Reimnitz, E.","contributorId":61557,"corporation":false,"usgs":true,"family":"Reimnitz","given":"E.","affiliations":[],"preferred":false,"id":440070,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70033349,"text":"70033349 - 2008 - Remote sensing and GIS approach for water-well site selection, southwest Iran","interactions":[],"lastModifiedDate":"2012-03-12T17:21:35","indexId":"70033349","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1574,"text":"Environmental & Engineering Geoscience","printIssn":"1078-7275","active":true,"publicationSubtype":{"id":10}},"title":"Remote sensing and GIS approach for water-well site selection, southwest Iran","docAbstract":"The Pabdeh-Lali Anticline of northern Khuzestan province is located in southwestern Iran and occupies 790 km2. This structure is situated in the Zagros folded belt. As a result of well-developed karst systems in the anticlinal axis, the water supply potential is high and is drained by many peripheral springs. However, there is a scarcity of water for agriculture and population centers on the anticlinal flanks, which imposes a severe problem in terms of area development. This study combines remotely sensed (RS) data and a geographical information system (GIS) into a RSGIS technique to delineate new areas for groundwater development and specific sites for drilling productive water wells. Toward these goals, RS data were used to develop GIS layers for lithology, structural geology, topographic slope, elevation, and drainage density. Field measurements were made to create spring-location and groundwater-quality GIS layers. Subsequently, expert choice and relational methods were used in a GIS environment to conjunctively analyze all layers to delineate preferable regions and 43 individual sites in which to drill water wells. Results indicate that the most preferred areas are, in preferential order, within recent alluvial deposits, the Bakhtiyari Conglomerates, and the Aghajari Sandstone. The Asmari Limestone and other units have much lower potential for groundwater supplies. Potential usefulness of the RSGIS method was indicated when six out of nine producing wells recently drilled by the Khozestan Water and Power Authority (which had no knowledge of this study) were located in areas preferentially selected by this technique.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental and Engineering Geoscience","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2113/gseegeosci.14.4.315","issn":"10787","usgsCitation":"Rangzan, K., Charchi, A., Abshirini, E., and Dinger, J., 2008, Remote sensing and GIS approach for water-well site selection, southwest Iran: Environmental & Engineering Geoscience, v. 14, no. 4, p. 315-326, https://doi.org/10.2113/gseegeosci.14.4.315.","startPage":"315","endPage":"326","numberOfPages":"12","costCenters":[],"links":[{"id":240997,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213376,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2113/gseegeosci.14.4.315"}],"volume":"14","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aa6f1e4b0c8380cd85129","contributors":{"authors":[{"text":"Rangzan, K.","contributorId":39589,"corporation":false,"usgs":true,"family":"Rangzan","given":"K.","email":"","affiliations":[],"preferred":false,"id":440450,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Charchi, A.","contributorId":82928,"corporation":false,"usgs":true,"family":"Charchi","given":"A.","email":"","affiliations":[],"preferred":false,"id":440452,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Abshirini, E.","contributorId":22972,"corporation":false,"usgs":true,"family":"Abshirini","given":"E.","email":"","affiliations":[],"preferred":false,"id":440449,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dinger, J.","contributorId":69788,"corporation":false,"usgs":true,"family":"Dinger","given":"J.","email":"","affiliations":[],"preferred":false,"id":440451,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70031765,"text":"70031765 - 2008 - Characterization of the shallow groundwater system in an alpine watershed: Handcart Gulch, Colorado, USA","interactions":[],"lastModifiedDate":"2017-09-26T10:00:09","indexId":"70031765","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1923,"text":"Hydrogeology Journal","active":true,"publicationSubtype":{"id":10}},"title":"Characterization of the shallow groundwater system in an alpine watershed: Handcart Gulch, Colorado, USA","docAbstract":"Water-table elevation measurements and aquifer parameter estimates are rare in alpine settings because few wells exist in these environments. Alpine groundwater systems may be a primary source of recharge to regional groundwater flow systems. Handcart Gulch is an alpine watershed in Colorado, USA comprised of highly fractured Proterozoic metamorphic and igneous rocks with wells completed to various depths. Primary study objectives include determining hydrologic properties of shallow bedrock and surficial materials, developing a watershed water budget, and testing the consistency of measured hydrologic properties and water budget by constructing a simple model incorporating groundwater and surface water for water year 2005. Water enters the study area as precipitation and exits as discharge in the trunk stream or potential recharge for the deeper aquifer. Surficial infiltration rates ranged from 0.1-6.2??0-5 m/s. Discharge was estimated at 1.28??10-3 km3. Numerical modeling analysis of single-well aquifer tests predicted lower specific storage in crystalline bedrock than in ferricrete and colluvial material (6.7??10-5-2.10??0-3 l/m). Hydraulic conductivity in crystalline bedrock was significantly lower than in colluvial and alluvial material (4.3??10-9 -2.0??10-4 m/s). Water budget results suggest that during normal precipitation and temperatures water is available to recharge the deeper groundwater flow system. ?? Springer-Verlag 2007.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrogeology Journal","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10040-007-0225-6","issn":"14312174","usgsCitation":"Kahn, K., Ge, S., Caine, J.S., and Manning, A., 2008, Characterization of the shallow groundwater system in an alpine watershed: Handcart Gulch, Colorado, USA: Hydrogeology Journal, v. 16, no. 1, p. 103-121, https://doi.org/10.1007/s10040-007-0225-6.","startPage":"103","endPage":"121","numberOfPages":"19","costCenters":[],"links":[{"id":240085,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212580,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10040-007-0225-6"}],"volume":"16","issue":"1","noUsgsAuthors":false,"publicationDate":"2007-11-27","publicationStatus":"PW","scienceBaseUri":"5059f4e7e4b0c8380cd4bfbf","contributors":{"authors":[{"text":"Kahn, Katherine G.","contributorId":174149,"corporation":false,"usgs":false,"family":"Kahn","given":"Katherine G.","affiliations":[],"preferred":false,"id":433027,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ge, Shemin","contributorId":37366,"corporation":false,"usgs":true,"family":"Ge","given":"Shemin","affiliations":[],"preferred":false,"id":433025,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Caine, Jonathan S. 0000-0002-7269-6989 jscaine@usgs.gov","orcid":"https://orcid.org/0000-0002-7269-6989","contributorId":1272,"corporation":false,"usgs":true,"family":"Caine","given":"Jonathan","email":"jscaine@usgs.gov","middleInitial":"S.","affiliations":[{"id":211,"text":"Crustal Geophysics and Geochemistry Science Center","active":true,"usgs":true}],"preferred":false,"id":433028,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Manning, A.","contributorId":73824,"corporation":false,"usgs":true,"family":"Manning","given":"A.","affiliations":[],"preferred":false,"id":433026,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70176654,"text":"70176654 - 2008 - Ecosystem conceptual model- Mercury ","interactions":[],"lastModifiedDate":"2016-09-23T15:28:47","indexId":"70176654","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":9,"text":"Other Report"},"title":"Ecosystem conceptual model- Mercury ","docAbstract":"Zinc and Cu play important roles in the biogeochemistry of natural systems, and it is likely that these interactions result in mass-dependent fractionations of their stable isotopes. In this study, we examine the relative abundances of dissolved Zn and Cu isotopes in a variety of stream waters draining six historical mining districts located in the United States and Europe. Our goals were to (1) determine whether streams from different geologic settings have unique or similar Zn and Cu isotopic signatures and (2) to determine whether Zn and Cu isotopic signatures change in response to changes in dissolved metal concentrations over well-defined diel (24-h) cycles.
Average δ66Zn and δ65Cu values for streams varied from +0.02‰ to +0.46‰ and −0.7‰ to +1.4‰, respectively, demonstrating that Zn and Cu isotopes are heterogeneous among the measured streams. Zinc or Cu isotopic changes were not detected within the resolution of our measurements over diel cycles for most streams. However, diel changes in Zn isotopes were recorded in one stream where the fluctuations of dissolved Zn were the largest. We calculate an apparent separation factor of ∼0.3‰ (66/64Zn) between the dissolved and solid Zn reservoirs in this stream with the solid taking up the lighter Zn isotope. The preference of the lighter isotope in the solid reservoir may reflect metabolic uptake of Zn by microorganisms. Additional field investigations must evaluate the contributions of soils, rocks, minerals, and anthropogenic components to Cu and Zn isotopic fluxes in natural waters. Moreover, rigorous experimental work is necessary to quantify fractionation factors for the biogeochemical reactions that are likely to impact Cu and Zn isotopes in hydrologic systems. This initial investigation of Cu and Zn isotopes in stream waters suggests that these isotopes may be powerful tools for probing biogeochemical processes in surface waters on a variety of temporal and spatial scales.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.gca.2007.11.014","issn":"00167037","usgsCitation":"Borrok, D.M., Nimick, D., Wanty, R.B., and Ridley, W.I., 2008, Isotopic variations of dissolved copper and zinc in stream waters affected by historical mining: Geochimica et Cosmochimica Acta, v. 72, no. 2, p. 329-344, https://doi.org/10.1016/j.gca.2007.11.014.","productDescription":"16 p.","startPage":"329","endPage":"344","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":241068,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213442,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.gca.2007.11.014"}],"volume":"72","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3fbfe4b0c8380cd647ae","contributors":{"authors":[{"text":"Borrok, David M.","contributorId":26056,"corporation":false,"usgs":true,"family":"Borrok","given":"David","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":440512,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nimick, David","contributorId":19643,"corporation":false,"usgs":true,"family":"Nimick","given":"David","affiliations":[],"preferred":false,"id":440514,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Wanty, Richard B. 0000-0002-2063-6423 rwanty@usgs.gov","orcid":"https://orcid.org/0000-0002-2063-6423","contributorId":443,"corporation":false,"usgs":true,"family":"Wanty","given":"Richard","email":"rwanty@usgs.gov","middleInitial":"B.","affiliations":[{"id":211,"text":"Crustal Geophysics and Geochemistry Science Center","active":true,"usgs":true}],"preferred":true,"id":440513,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Ridley, William I. 0000-0001-6787-558X iridley@usgs.gov","orcid":"https://orcid.org/0000-0001-6787-558X","contributorId":1160,"corporation":false,"usgs":true,"family":"Ridley","given":"William","email":"iridley@usgs.gov","middleInitial":"I.","affiliations":[{"id":171,"text":"Central Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":440515,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70033370,"text":"70033370 - 2008 - A characterization of non-biotic environmental features of prairies hosting the Dakota Skipper (Hesperia dacotae, Hesperiidae) across its remaining U.S. range","interactions":[],"lastModifiedDate":"2018-01-05T10:30:54","indexId":"70033370","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2557,"text":"Journal of the Lepidopterists' Society","active":true,"publicationSubtype":{"id":10}},"title":"A characterization of non-biotic environmental features of prairies hosting the Dakota Skipper (Hesperia dacotae, Hesperiidae) across its remaining U.S. range","docAbstract":"Within the United States, the Dakota Skipper now occurs only in Minnesota, North Dakota, and South Dakota. In these states it has been associated with margins of glacial lakes and calcareous mesic prairies that host warm-season native grasses. Preliminary geographic information system (GIS) analysis in North Dakota has indicated a close congruency between historic distribution of the Dakota Skipper and that of specific near-shore glacial lake features and related soil associations. This study analyzed humidity-related non-biotic microhabitat characteristics within three remaining occupied Dakota Skipper sites in each state during the larval growth period in 2000. Measured parameters included topographic relief, soil compaction, soil pH, moisture, and temperature at various depths, soil bulk density, soil texture, and temperature and humidity within the larval nest zone. Results of these efforts reveal two distinctive habitat substrates, one of relatively low surface relief with dense but relatively less compact soils, and another of relatively high relief with less dense but more compact soils. In the low-relief habitat, grazing appears to compact soils unfavorably in otherwise similar prairies in the more xeric western portion of the range, potentially by affecting ground-water buffering of larval nest zone humidity.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of the Lepidopterists' Society","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00240966","usgsCitation":"Royer, R., McKenney, R., and Newton, W., 2008, A characterization of non-biotic environmental features of prairies hosting the Dakota Skipper (Hesperia dacotae, Hesperiidae) across its remaining U.S. range: Journal of the Lepidopterists' Society, v. 62, no. 1, p. 1-17.","productDescription":"17 p.","startPage":"1","endPage":"17","costCenters":[{"id":480,"text":"Northern Prairie Wildlife Research Center","active":true,"usgs":true}],"links":[{"id":241104,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"62","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e33fe4b0c8380cd45ede","contributors":{"authors":[{"text":"Royer, R.A.","contributorId":99500,"corporation":false,"usgs":true,"family":"Royer","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":440549,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McKenney, R.A.","contributorId":57885,"corporation":false,"usgs":true,"family":"McKenney","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":440548,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Newton, W.E.","contributorId":13567,"corporation":false,"usgs":true,"family":"Newton","given":"W.E.","email":"","affiliations":[],"preferred":false,"id":440547,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70033376,"text":"70033376 - 2008 - Environmental occurrence of the enterococcal surface protein (esp) gene is an unreliable indicator of human fecal contamination","interactions":[],"lastModifiedDate":"2012-12-19T13:11:11","indexId":"70033376","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Environmental occurrence of the enterococcal surface protein (esp) gene is an unreliable indicator of human fecal contamination","docAbstract":"The enterococcal surface protein (esp) gene found in Enterococcus faecalis and E. faecium has recently been explored as a marker of sewage pollution in recreational waters but its occurrence and distribution in environmental enterococci has not been well-documented. If the esp gene is found in environmental samples, there are potential implications for microbial source tracking applications. In the current study, a total of 452 samples (lake water, 100; stream water, 129; nearshore sand, 96; and backshore sand, 71; Cladophora sp. (Chlorophyta), 41; and periphyton (mostly Bacillariophyceae), 15) collected from the coastal watersheds of southern Lake Michigan were selectively cultured for enterococci and then analyzed for the esp gene by PCR, targeting E. faecalis/ E. faecium (espfs/fm) and E. faecium (espfm). Overall relative frequencies for espfs/fm and espfm were 27.4 and 5.1%. Respective percent frequency for the espfs/fm and espfm was 36 and 14% in lake water; 38.8 and 2.3% in stream water; 24 and 6.3% in nearshore sand; 0% in backshore sand; 24.4 and 0% in Cladophora sp.; and 33.3 and 0% in periphyton. The overall occurrence of both espfs/fm and espfm was significantly related (χ2 = 49, P < 0.0001). Post-rain incidence of espfs/fm increased in lake and stream water and nearshore sand. Further, E. coli and enterococci cell densities were significant predictors for espfs/fm occurrence in post-rain lake water, but espfm was not. F+ coliphage densities were not significant predictors for espfm or espfs/fm gene incidence. In summary, the differential occurrence of the esp gene in the environment suggests that it is not limited to human fecal sources and thus may weaken its use as a reliable tool in discriminating contaminant sources (i.e., human vs nonhuman).","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Science and Technology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1021/es800481p","issn":"00139","usgsCitation":"Byappanahalli, M., Przybyla-Kelly, K., Shively, D., and Whitman, R., 2008, Environmental occurrence of the enterococcal surface protein (esp) gene is an unreliable indicator of human fecal contamination: Environmental Science & Technology, v. 42, no. 21, p. 8014-8020, https://doi.org/10.1021/es800481p.","startPage":"8014","endPage":"8020","numberOfPages":"7","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":241138,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213509,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es800481p"}],"volume":"42","issue":"21","noUsgsAuthors":false,"publicationDate":"2008-10-03","publicationStatus":"PW","scienceBaseUri":"505a09d6e4b0c8380cd520b0","contributors":{"authors":[{"text":"Byappanahalli, M.N.","contributorId":11384,"corporation":false,"usgs":true,"family":"Byappanahalli","given":"M.N.","email":"","affiliations":[],"preferred":false,"id":440570,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Przybyla-Kelly, K.","contributorId":23332,"corporation":false,"usgs":true,"family":"Przybyla-Kelly","given":"K.","email":"","affiliations":[],"preferred":false,"id":440571,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Shively, D.A.","contributorId":78123,"corporation":false,"usgs":true,"family":"Shively","given":"D.A.","email":"","affiliations":[],"preferred":false,"id":440573,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Whitman, R.L.","contributorId":69750,"corporation":false,"usgs":true,"family":"Whitman","given":"R.L.","email":"","affiliations":[],"preferred":false,"id":440572,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70033379,"text":"70033379 - 2008 - Population genetic structure in Atlantic and Pacific Ocean common murres (Uria aalge): Natural replicate tests of post-Pleistocene evolution","interactions":[],"lastModifiedDate":"2017-07-19T15:16:04","indexId":"70033379","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2774,"text":"Molecular Ecology","active":true,"publicationSubtype":{"id":10}},"title":"Population genetic structure in Atlantic and Pacific Ocean common murres (Uria aalge): Natural replicate tests of post-Pleistocene evolution","docAbstract":"Understanding the factors that influence population differentiation in temperate taxa can be difficult because the signatures of both historic and contemporary demographics are often reflected in population genetic patterns. Fortunately, analyses based on coalescent theory can help untangle the relative influence of these historic and contemporary factors. Common murres (Uria aalge) are vagile seabirds that breed in the boreal and low arctic waters of the Northern Hemisphere. Previous analyses revealed that Atlantic and Pacific populations are genetically distinct; however, less is known about population genetic structure within ocean basins. We employed the mitochondrial control region, four microsatellite loci and four intron loci to investigate population genetic structure throughout the range of common murres. As in previous studies, we found that Atlantic and Pacific populations diverged during the Pleistocene and do not currently exchange migrants. Therefore, Atlantic and Pacific murre populations can be used as natural replicates to test mechanisms of population differentiation. While we found little population genetic structure within the Pacific, we detected significant east-west structuring among Atlantic colonies. The degree that population genetic structure reflected contemporary population demographics also differed between ocean basins. Specifically, while the low levels of population differentiation in the Pacific are at least partially due to high levels of contemporary gene flow, the east-west structuring of populations within the Atlantic appears to be the result of historic fragmentation of populations rather than restricted contemporary gene flow. The contrasting results in the Atlantic and Pacific Oceans highlight the necessity of carefully considering multilocus nonequilibrium population genetic approaches when reconstructing the demographic history of temperate Northern Hemisphere taxa. ?? 2008 The Authors.
","language":"English","publisher":"Wiley","doi":"10.1111/j.1365-294X.2008.03977.x","issn":"09621","usgsCitation":"Morris-Pocock, J.A., Taylor, S., Birt, T., Damus, M., Piatt, J.F., Warheit, K., and Friesen, V.L., 2008, Population genetic structure in Atlantic and Pacific Ocean common murres (Uria aalge): Natural replicate tests of post-Pleistocene evolution: Molecular Ecology, v. 17, no. 22, p. 4859-4873, https://doi.org/10.1111/j.1365-294X.2008.03977.x.","productDescription":"15 p.","startPage":"4859","endPage":"4873","costCenters":[],"links":[{"id":241139,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","issue":"22","noUsgsAuthors":false,"publicationDate":"2008-12-03","publicationStatus":"PW","scienceBaseUri":"505a7d72e4b0c8380cd79f55","contributors":{"authors":[{"text":"Morris-Pocock, J. A.","contributorId":61653,"corporation":false,"usgs":true,"family":"Morris-Pocock","given":"J.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":440585,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Taylor, S.A.","contributorId":100200,"corporation":false,"usgs":true,"family":"Taylor","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":440588,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Birt, T.P.","contributorId":82411,"corporation":false,"usgs":true,"family":"Birt","given":"T.P.","email":"","affiliations":[],"preferred":false,"id":440586,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Damus, M.","contributorId":20987,"corporation":false,"usgs":true,"family":"Damus","given":"M.","affiliations":[],"preferred":false,"id":440583,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Piatt, John F. 0000-0002-4417-5748 jpiatt@usgs.gov","orcid":"https://orcid.org/0000-0002-4417-5748","contributorId":3025,"corporation":false,"usgs":true,"family":"Piatt","given":"John","email":"jpiatt@usgs.gov","middleInitial":"F.","affiliations":[{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true},{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true},{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"preferred":true,"id":440587,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Warheit, K.I.","contributorId":100796,"corporation":false,"usgs":true,"family":"Warheit","given":"K.I.","email":"","affiliations":[],"preferred":false,"id":440589,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Friesen, Vicki L.","contributorId":59407,"corporation":false,"usgs":false,"family":"Friesen","given":"Vicki","email":"","middleInitial":"L.","affiliations":[{"id":7029,"text":"Queen's University, Kingston, Ontario, Canada","active":true,"usgs":false}],"preferred":false,"id":440584,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70033721,"text":"70033721 - 2008 - Factors controlling nitrogen release from two forested catchments with contrasting hydrochemical responses","interactions":[],"lastModifiedDate":"2018-10-22T10:48:33","indexId":"70033721","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"Factors controlling nitrogen release from two forested catchments with contrasting hydrochemical responses","docAbstract":"Quantifying biogeochemical cycles of nitrogen (N) and the associated fluxes to surface waters remains challenging, given the need to deal with spatial and temporal variability and to characterize complex and heterogeneous landscapes. We focused our study on catchments S14 and S15 located in the Adirondack Mountains of New York, USA, which have similar topographic and hydrologic characteristics but contrasting stream nitrate ($\\hbox{NO}_{3}^{-}$) concentrations. We characterized the mechanisms by which $\\hbox{NO}_{3}^{-}$ reaches the streams during hydrological events in these catchments, aiming to reconcile our field data with our conceptual model of factors that regulate nutrient exports from forested catchments. Combined hydrometric, chemical and isotopic (δ$\\hbox{NO}_{3}^{-}$) data showed that the relative contributions of both soil and ground water sources were similar between the two catchments. Temporal patterns of stream chemistry were markedly different between S14 and S15, however, because the water sources in the two catchments have different solute concentrations. During late summer/fall, the largest source of $\\hbox{NO}_{3}^{-}$ in S14 was till groundwater, whereas shallow soil was the largest $\\hbox{NO}_{3}^{-}$ source in S15. $\\hbox{NO}_{3}^{-}$ concentrations in surface water decreased in S14, whereas they increased in S15 because an increasing proportion of stream flow was derived from shallow soil sources. During snowmelt, the largest sources of $\\hbox{NO}_{3}^{-}$were in the near‐surface soil in both catchments. Concentrations of $\\hbox{NO}_{3}^{-}$ increased as stream discharge increased and usually peaked before peak discharge, when shallow soil water sources made the largest contribution to stream discharge. The timing of peaks in stream $\\hbox{NO}_{3}^{-}$concentrations was affected by antecedent moisture conditions. By elucidating the factors that affect sources and transport of N, including differences in the soil nutrient cycling and hydrological characteristics of S14 and S15, this study contributes to the overall conceptualization of $\\hbox{NO}_{3}^{-}$ release from temperate forested catchments.
Treated wastewater effluent is a potential environmental point source for antidepressant pharmaceuticals. A quantitative method was developed for the determination of trace levels of antidepressants in environmental aquatic matrixes using solid-phase extraction coupled with liquid chromatography-electrospray ionization tandem mass spectrometry. Recoveries of parent antidepressants from matrix spiking experiments for the individual antidepressants ranged from 72 to 118% at low concentrations (0.5 ng/L) and 70 to 118% at high concentrations (100 ng/L) for the solid-phase extraction method. Method detection limits for the individual antidepressant compounds ranged from 0.19 to 0.45 ng/L. The method was applied to wastewater effluent and samples collected from a wastewater-dominated stream. Venlafaxine was the predominant antidepressant observed in wastewater and river water samples. Individual antidepressant concentrations found in the wastewater effluent ranged from 3 (duloxetine) to 2190 ng/L (venlafaxine), whereas individual concentrations in the waste-dominated stream ranged from 0.72 (norfluoxetine) to 1310 ng/L (venlafaxine).
The shallow‐water equations are used to model the flow resulting from the sudden release of a finite volume of frictionless, incompressible fluid down a uniform slope of arbitrary inclination. The hodograph transformation and Riemann's method make it possible to transform the governing equations into a linear system and then deduce an exact analytical solution expressed in terms of readily evaluated integrals. Although the solution treats an idealized case never strictly realized in nature, it is uniquely well‐suited for testing the robustness and accuracy of numerical models used to model shallow‐water flows on steep slopes.
","language":"English","publisher":"AGU","doi":"10.1029/2007WR006353","issn":"00431397","usgsCitation":"Ancey, C., Iverson, R.M., Rentschler, M., and Denlinger, R.P., 2008, An exact solution for ideal dam-break floods on steep slopes: Water Resources Research, v. 44, no. 1, W01430, https://doi.org/10.1029/2007WR006353.","productDescription":"W01430","costCenters":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true},{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"links":[{"id":487748,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://infoscience.epfl.ch/handle/20.500.14299/20492","text":"External Repository"},{"id":242226,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":214493,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2007WR006353"}],"volume":"44","issue":"1","noUsgsAuthors":false,"publicationDate":"2008-01-25","publicationStatus":"PW","scienceBaseUri":"5059ea5ee4b0c8380cd487f6","contributors":{"authors":[{"text":"Ancey, C.","contributorId":9476,"corporation":false,"usgs":true,"family":"Ancey","given":"C.","email":"","affiliations":[],"preferred":false,"id":442112,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Iverson, Richard M. 0000-0002-7369-3819 riverson@usgs.gov","orcid":"https://orcid.org/0000-0002-7369-3819","contributorId":536,"corporation":false,"usgs":true,"family":"Iverson","given":"Richard","email":"riverson@usgs.gov","middleInitial":"M.","affiliations":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true},{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":true,"id":442113,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rentschler, M.","contributorId":62848,"corporation":false,"usgs":true,"family":"Rentschler","given":"M.","email":"","affiliations":[],"preferred":false,"id":442115,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Denlinger, Roger P. 0000-0003-0930-0635 roger@usgs.gov","orcid":"https://orcid.org/0000-0003-0930-0635","contributorId":2679,"corporation":false,"usgs":true,"family":"Denlinger","given":"Roger","email":"roger@usgs.gov","middleInitial":"P.","affiliations":[{"id":615,"text":"Volcano Hazards Program","active":true,"usgs":true},{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":true,"id":442114,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70033399,"text":"70033399 - 2008 - Eddy correlation measurements of submarine groundwater discharge","interactions":[],"lastModifiedDate":"2018-05-02T21:26:13","indexId":"70033399","displayToPublicDate":"2008-01-01T00:00:00","publicationYear":"2008","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2662,"text":"Marine Chemistry","active":true,"publicationSubtype":{"id":10}},"title":"Eddy correlation measurements of submarine groundwater discharge","docAbstract":"This paper presents a new, non-invasive means of quantifying groundwater discharge into marine waters using an eddy correlation approach. The method takes advantage of the fact that, in virtually all aquatic environments, the dominant mode of vertical transport near the sediment–water interface is turbulent mixing. The technique thus relies on measuring simultaneously the fluctuating vertical velocity using an acoustic Doppler velocimeter and the fluctuating salinity and/or temperature using rapid-response conductivity and/or temperature sensors. The measurements are typically done at a height of 5–15 cm above the sediment surface, at a frequency of 16 to 64 Hz, and for a period of 15 to 60 min. If the groundwater salinity and/or temperature differ from that of the water column, the groundwater specific discharge (cm d− 1) can be quantified from either a heat or salt balance. Groundwater discharge was estimated with this new approach in Salt Pond, a small estuary on Cape Cod (MA, USA). Estimates agreed well with previous estimates of discharge measured using seepage meters and 222Rn as a tracer. The eddy correlation technique has several desirable characteristics: 1) discharge is quantified under in-situ hydrodynamic conditions; 2) salinity and temperature can serve as two semi-independent tracers of discharge; 3) discharge can be quantified at high temporal resolution, and 4) long-term records of discharge may be possible, due to the low power requirements of the instrumentation.