Following the aggressive invasion of the bivalve, Potamocorbula amurensis, in the San Francisco Bay-Delta in 1986, selenium contamination in the benthic food web increased. Concentrations in this dominant (exotic) bivalve in North Bay were three times higher in 1995–1997 than in earlier studies, and 1990 concentrations in benthic predators (sturgeon and diving ducks) were also higher than in 1986. The contamination was widespread, varied seasonally and was greater in P. amurensis than in co-occurring and transplanted species. Selenium concentrations in the water column of the Bay were enriched relative to the Sacramento River but were not as high as observed in many contaminated aquatic environments. Total Se concentrations in the dissolved phase never exceeded 0.3 μg Se per l in 1995 and 1996; Se concentrations on particulate material ranged from 0.5 to 2.0 μg Se per g dry weight (dw) in the Bay. Nevertheless, concentrations in P. amurensis reached as high as 20 μg Se per g dw in October 1996. The enriched concentrations in bivalves (6–20 μg Se per g dw) were widespread throughout North San Francisco Bay in October 1995 and October 1996. Concentrations varied seasonally from 5 to 20 μg Se per g dw, and were highest during the periods of lowest river inflows and lowest after extended high river inflows. Transplanted bivalves (oysters, mussels or clams) were not effective indicators of either the degree of Se contamination in P. amurensis or the seasonal increases in contamination in the resident benthos. Se is a potent environmental toxin that threatens higher trophic level species because of its reproductive toxicity and efficient food web transfer. Bivalves concentrate selenium effectively because they bioaccumulate the element strongly and lose it slowly; and they are a direct link in the exposure of predaceous benthivore species. Biological invasions of estuaries are increasing worldwide. Changes in ecological structure and function are well known in response to invasions. This study shows that changes in processes such as cycling and effects of contaminants can accompany such invasions.
The transport and attachment behaviors of Spumella guttula (Kent), a nanoflagellate (protist) found in contaminated and uncontaminated aquifer sediments in Cape Cod, Mass., were assessed in flowthrough and static columns and in a field injection-and-recovery transport experiment involving an array of multilevel samplers. Transport of S. guttula harvested from low-nutrient (10 mg of dissolved organic carbon per liter), slightly acidic, granular (porous) growth media was compared to earlier observations involving nanoflagellates grown in a traditional high-nutrient liquid broth. In contrast to the highly retarded (retardation factor of ∼3) subsurface transport previously reported for S. guttula, the peak concentration of porous-medium-grown S. guttulatraveled concomitantly with that of a conservative (bromide) tracer. About one-third of the porous-medium-grown nanoflagellates added to the aquifer were transported at least 2.8 m downgradient, compared to only ∼2% of the broth-grown nanoflagellates. Flowthrough column studies revealed that a vital (hydroethidine [HE]) staining procedure resulted in considerably less attachment (more transport) of S. guttula in aquifer sediments than did a staining-and-fixation procedure involving 4′,6′-diamidino-2-phenylindole (DAPI) and glutaraldehyde. The calculated collision efficiency (∼10−2 for porous-medium-grown, DAPI-stained nanoflagellates) was comparable to that observed earlier for the indigenous community of unattached groundwater bacteria that serve as prey. The attachment of HE-labeled S. guttula onto aquifer sediment grains was independent of pH (over the range from pH 3 to 9) suggesting a primary attachment mechanism that may be fundamentally different from that of their prey bacteria, which exhibit sharp decreases in fractional attachment with increasing pH. The high degree of mobility of S. guttula in the aquifer sediments has important ecological implications for the protistan community within the temporally changing plume of organic contaminants in the Cape Cod aquifer.
Near Mirror Lake, New Hampshire (USA), hydraulically conductive, fractured bedrock was investigated with the crosswell seismic method to determine whether this method could provide any information about hydraulic conductivity between wells. To this end, crosswell seismic data, acoustic logs from boreholes, image logs from boreholes, and single borehole hydraulic tests were analyzed. The analysis showed that, first, the P-wave velocities from the acoustic logs tended to be higher in schist than they were in granite. (Schist and granite were the dominant rock types). Second, the P-wave velocities from the acoustic logs tended to be low near fractures. Third, the hydraulic conductivity was always low (always less than to 10−8 m/s) where no fractures intersected the borehole, but the hydraulic conductivity ranged from low to high (from less than to 10−10 m/s to 10−4 m/s) where one or more fractures intersected the borehole. Fourth, high hydraulic conductivities were slightly more frequent when the P-wave velocity was low (less than 5200 m/s) than when it was high (greater than or equal to 5200 m/s). The interpretation of this statistical relation was that the fractures tended to increase the hydraulic conductivity and to lower the P-wave velocity. This statistical relation was applied to a velocity tomogram to create a map showing the probability of high hydraulic conductivity; the map was consistent with results from independent hydraulic tests.
Parasites and pathogens can influence the survivorship, behavior, and very structure of their host species. For example, experimental studies have shown that trematode parasites can cause high frequencies of severe limb malformations in amphibians. In a broad-scale field survey covering parts of California, Oregon, Washington, Idaho, and Montana, we examined relationships between the frequency and types of morphological abnormalities in amphibians and the abundance of trematode parasite infection, pH, concentrations of 61 pesticides, and levels of orthophosphate and total nitrate. We recorded severe malformations at frequencies ranging from 1% to 90% in nine amphibian species from 53 aquatic systems. Infection of larvae by the trematode Ribeiroia ondatrae was associated with, and functionally related to, higher frequencies of amphibian limb malformations than found in uninfected populations (≤5%). Parasites were concentrated around the basal tissue of hind limbs in infected anurans, and malformations associated with infection included skin webbings, supernumerary limbs and digits, and missing or malformed hind limbs. In the absence of Ribeiroia, amphibian populations exhibited low (0-5%) frequencies of abnormalities involving missing digits or distal portions of a hind limb. Species were affected differentially by the parasite, and Ambystoma macrodactylum, Hyla regilla, Rand aurora, R. luteiventris, and Taricha torosa typically exhibited the highest frequencies of abnormalities. None of the water-quality variables measured was associated with malformed amphibians, but aquatic snail hosts (Planorbella spp.) were significant predictors of the presence and abundance of Ribeiroia infection. Morphological comparisons of adult specimens of Ribeiroia collected from different sites and raised in experimental definitive hosts suggested that all samples represented the same species - R. ondatrae. These field results, coupled with experimental research on the effects of Ribeiroia on amphibians, demonstrate that Ribeiroia infection is an important and widespread cause of amphibian limb malformations in the western United States. The relevance of trematode infection to declines of amphibian populations and the influence of habitat modification on the pathology and life cycle of Ribeiroia are emphasized as areas requiring further research.
","language":"English","publisher":"ESA","doi":"10.1890/0012-9615(2002)072[0151:PROILT]2.0.CO;2","issn":"00129615","usgsCitation":"Johnson, P., Lunde, K., Thurman, E., Ritchie, E., Wray, S., Sutherland, D., Kapfer, J., Frest, T., Bowerman, J., and Blaustein, A., 2002, Parasite (Ribeiroia ondatrae) infection linked to amphibian malformations in the western United States: Ecological Monographs, v. 72, no. 2, p. 151-168, https://doi.org/10.1890/0012-9615(2002)072[0151:PROILT]2.0.CO;2.","productDescription":"18 p.","startPage":"151","endPage":"168","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":233308,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","volume":"72","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a74d6e4b0c8380cd77867","contributors":{"authors":[{"text":"Johnson, P.T.J.","contributorId":104255,"corporation":false,"usgs":true,"family":"Johnson","given":"P.T.J.","email":"","affiliations":[],"preferred":false,"id":401934,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lunde, K.B.","contributorId":10200,"corporation":false,"usgs":true,"family":"Lunde","given":"K.B.","email":"","affiliations":[],"preferred":false,"id":401925,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Thurman, E.M.","contributorId":102864,"corporation":false,"usgs":true,"family":"Thurman","given":"E.M.","affiliations":[],"preferred":false,"id":401933,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Ritchie, E.G.","contributorId":97285,"corporation":false,"usgs":true,"family":"Ritchie","given":"E.G.","email":"","affiliations":[],"preferred":false,"id":401932,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Wray, S.N.","contributorId":90505,"corporation":false,"usgs":true,"family":"Wray","given":"S.N.","email":"","affiliations":[],"preferred":false,"id":401930,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Sutherland, D.R.","contributorId":15376,"corporation":false,"usgs":true,"family":"Sutherland","given":"D.R.","email":"","affiliations":[],"preferred":false,"id":401926,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Kapfer, J.M.","contributorId":68505,"corporation":false,"usgs":true,"family":"Kapfer","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":401928,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Frest, T.J.","contributorId":70964,"corporation":false,"usgs":true,"family":"Frest","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":401929,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Bowerman, J.","contributorId":94824,"corporation":false,"usgs":true,"family":"Bowerman","given":"J.","email":"","affiliations":[],"preferred":false,"id":401931,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Blaustein, A.R.","contributorId":40325,"corporation":false,"usgs":true,"family":"Blaustein","given":"A.R.","affiliations":[],"preferred":false,"id":401927,"contributorType":{"id":1,"text":"Authors"},"rank":10}]}} ,{"id":70024589,"text":"70024589 - 2002 - Fluvial sediment transport and deposition following the 1991 eruption of Mount Pinatubo","interactions":[],"lastModifiedDate":"2012-03-12T17:20:14","indexId":"70024589","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1801,"text":"Geomorphology","active":true,"publicationSubtype":{"id":10}},"title":"Fluvial sediment transport and deposition following the 1991 eruption of Mount Pinatubo","docAbstract":"The 1991 eruption of Mount Pinatubo generated extreme sediment yields from watersheds heavily impacted by pyroclastic flows. Bedload sampling in the Pasig-Potrero River, one of the most heavily impacted rivers, revealed negligible critical shear stress and very high transport rates that reflected an essentially unlimited sediment supply and the enhanced mobility of particles moving over a smooth, fine-grained bed. Dimensionless bedload transport rates in the Pasig-Potrero River differed substantially from those previously reported for rivers in temperate regions for the same dimensionless shear stress, but were similar to rates identified in rivers on other volcanoes and ephemeral streams in arid environments. The similarity between volcanically disturbed and arid rivers appears to arise from the lack of an armored bed surface due to very high relative sediment supply; in arid rivers, this is attributed to a flashy hydrograph, whereas volcanically disturbed rivers lack armoring due to sustained high rates of sediment delivery. This work suggests that the increases in sediment supply accompanying massive disturbance induce morphologic and hydrologic changes that temporarily enhance transport efficiency until the watershed recovers and sediment supply is reduced. ?? 2002 Elsevier Science B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geomorphology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0169-555X(01)00155-6","issn":"0169555X","usgsCitation":"Hayes, S., Montgomery, D.R., and Newhall, C.G., 2002, Fluvial sediment transport and deposition following the 1991 eruption of Mount Pinatubo: Geomorphology, v. 45, no. 3-4, p. 211-224, https://doi.org/10.1016/S0169-555X(01)00155-6.","startPage":"211","endPage":"224","numberOfPages":"14","costCenters":[],"links":[{"id":207641,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0169-555X(01)00155-6"},{"id":232769,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"45","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a12a4e4b0c8380cd543a4","contributors":{"authors":[{"text":"Hayes, S.K.","contributorId":81667,"corporation":false,"usgs":true,"family":"Hayes","given":"S.K.","email":"","affiliations":[],"preferred":false,"id":401808,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Montgomery, D. R.","contributorId":41582,"corporation":false,"usgs":false,"family":"Montgomery","given":"D.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":401807,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Newhall, C. G.","contributorId":93056,"corporation":false,"usgs":true,"family":"Newhall","given":"C.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":401809,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70024574,"text":"70024574 - 2002 - Effects of tidal shallowing and deepening on phytoplankton production dynamics: A modeling study","interactions":[],"lastModifiedDate":"2018-11-26T10:39:16","indexId":"70024574","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1583,"text":"Estuaries","active":true,"publicationSubtype":{"id":10}},"title":"Effects of tidal shallowing and deepening on phytoplankton production dynamics: A modeling study","docAbstract":"Processes influencing estuarine phytoplankton growth occur over a range of time scales, but many conceptual and numerical models of estuarine phytoplankton production dynamics neglect mechanisms occurring on the shorter (e.g., intratidal) time scales. We used a numerical model to explore the influence of short time-scale variability in phytoplankton sources and sinks on long-term growth in an idealized water column that shallows and deepens with the semidiurnal tide. Model results show that tidal fluctuations in water surface elevation can determine whether long-term phytoplankton growth is positive or negative. Hourly-scale interactions influencing weekly-scale to monthly-scale phytoplankton dynamics include intensification of the depth-averaged benthic grazing effect by water column shallowing and enhancement of water column photosynthesis when solar noon coincides with low tide. Photosynthesis and benthic consumption may modulate over biweekly time scales due to spring-neap fluctuations in tidal range and the 15-d cycle of solar noon-low tide phasing. If tidal range is a large fraction of mean water depth, then tidal shallowing and deepening may significantly influence net phytoplankton growth. In such a case, models or estimates of long-term phytoplankton production dynamics that neglect water surface fluctuations may overestimate or underestimate net growth and could even predict the wrong sign associated with net growth rate.
","language":"English","publisher":"Springer","doi":"10.1007/BF02804885","issn":"01608347","usgsCitation":"Lucas, L., and Cloern, J., 2002, Effects of tidal shallowing and deepening on phytoplankton production dynamics: A modeling study: Estuaries, v. 25, no. 4 A, p. 497-507, https://doi.org/10.1007/BF02804885.","productDescription":"11 p.","startPage":"497","endPage":"507","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true},{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true},{"id":5079,"text":"Pacific Regional Director's Office","active":true,"usgs":true}],"links":[{"id":233162,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"25","issue":"4 A","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a080de4b0c8380cd51955","contributors":{"authors":[{"text":"Lucas, L.V.","contributorId":62777,"corporation":false,"usgs":true,"family":"Lucas","given":"L.V.","email":"","affiliations":[],"preferred":false,"id":401754,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cloern, J. E.","contributorId":59453,"corporation":false,"usgs":true,"family":"Cloern","given":"J. E.","affiliations":[],"preferred":false,"id":401753,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70024552,"text":"70024552 - 2002 - Movement of water through the thick unsaturated zone underlying Oro Grande and Sheep Creek Washes in the western Mojave Desert, USA","interactions":[],"lastModifiedDate":"2018-09-19T08:36:41","indexId":"70024552","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"Movement of water through the thick unsaturated zone underlying Oro Grande and Sheep Creek Washes in the western Mojave Desert, USA","docAbstract":"Previous studies indicate that a small quantity of recharge occurs from infiltration of streamflow in intermittent streams in the upper Mojave River basin, in the western Mojave Desert, near Victorville, California. Chloride, tritium, and stable isotope data collected in the unsaturated zone between 1994 and 1998 from boreholes drilled in Oro Grande and Sheep Creek Washes indicate that infiltration of streamflow occurs to depths below the root zone, and presumably to the water table, along much of Oro Grande Wash and near the mountain front along Sheep Creek Wash. Differences in infiltration at sites along each wash are the result of hydrologic variables such as proximity to the mountain front, quantity of streamflow, and texture of the subsurface deposits. Differences in infiltration between the washes are the result of large-scale geomorphic processes. For example, Oro Grande wash is incised into the Victorville fan and infiltration has occurred at approximately the same location over recent geologic time. In contrast, Sheep Creek Wash overlies an active alluvial fan and the stream channel can move across the fan surface through time. Infiltration does not occur to depths below the root zone at control sites outside of the washes.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrogeology Journal","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10040-002-0194-8","issn":"14312174","usgsCitation":"Izbicki, J., Radyk, J., and Michel, R.L., 2002, Movement of water through the thick unsaturated zone underlying Oro Grande and Sheep Creek Washes in the western Mojave Desert, USA: Hydrogeology Journal, v. 10, no. 3, p. 409-427, https://doi.org/10.1007/s10040-002-0194-8.","startPage":"409","endPage":"427","numberOfPages":"19","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":232843,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":207685,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10040-002-0194-8"}],"volume":"10","issue":"3","noUsgsAuthors":false,"publicationDate":"2002-04-24","publicationStatus":"PW","scienceBaseUri":"505a5f27e4b0c8380cd70dd5","contributors":{"authors":[{"text":"Izbicki, J. A. 0000-0003-0816-4408","orcid":"https://orcid.org/0000-0003-0816-4408","contributorId":28244,"corporation":false,"usgs":true,"family":"Izbicki","given":"J. A.","affiliations":[],"preferred":false,"id":401686,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Radyk, J.","contributorId":63984,"corporation":false,"usgs":true,"family":"Radyk","given":"J.","email":"","affiliations":[],"preferred":false,"id":401687,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Michel, R. L.","contributorId":86375,"corporation":false,"usgs":true,"family":"Michel","given":"R.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":401688,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70024548,"text":"70024548 - 2002 - 15N NMR investigation of the reduction and binding of TNT in an aerobic bench scale reactor simulating windrow composting","interactions":[],"lastModifiedDate":"2020-01-04T14:00:13","indexId":"70024548","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","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":"15N NMR investigation of the reduction and binding of TNT in an aerobic bench scale reactor simulating windrow composting","docAbstract":"T15NT was added to a soil of low organic carbon content and composted for 20 days in an aerobic bench scale reactor. The finished whole compost and fulvic acid, humic acid, humin, and lignocellulose fractions extracted from the compost were analyzed by solid-state CP/MAS and DP/MAS 15N NMR. 15N NMR spectra provided direct spectroscopic evidence for reduction of TNT followed by covalent binding of the reduced metabolites to organic matter of the composted soil, with the majority of metabolite found in the lignocellulose fraction, by mass also the major fraction of the compost. In general, the types of bonds formed between soil organic matter and reduced TNT amines in controlled laboratory reactions were observed in the spectra of the whole compost and fractions, confirming that during composting TNT is reduced to amines that form covalent bonds with organic matter through aminohydroquinone, aminoquinone, heterocyclic, and imine linkages, among others. Concentrations of imine nitrogens in the compost spectra suggestthat covalent binding bythe diamines 2,4DANT and 2,6DANT is a significant process in the transformation of TNT into bound residues. Liquid-phase 15N NMR spectra of the fulvic acid and humin fractions provided possible evidence for involvement of phenoloxidase enzymes in covalent bond formation.","language":"English","publisher":"ACS","doi":"10.1021/es011382r","issn":"0013936X","usgsCitation":"Thorn, K.A., Pennington, J., and Hayes, C., 2002, 15N NMR investigation of the reduction and binding of TNT in an aerobic bench scale reactor simulating windrow composting: Environmental Science & Technology, v. 36, no. 17, p. 3797-3805, https://doi.org/10.1021/es011382r.","productDescription":"9 p.","startPage":"3797","endPage":"3805","numberOfPages":"9","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":232764,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"36","issue":"17","noUsgsAuthors":false,"publicationDate":"2002-08-06","publicationStatus":"PW","scienceBaseUri":"5059e227e4b0c8380cd459d8","contributors":{"authors":[{"text":"Thorn, K. A.","contributorId":33294,"corporation":false,"usgs":true,"family":"Thorn","given":"K.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":401670,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Pennington, J.C.","contributorId":105085,"corporation":false,"usgs":true,"family":"Pennington","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":401672,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hayes, C.A.","contributorId":50691,"corporation":false,"usgs":true,"family":"Hayes","given":"C.A.","email":"","affiliations":[],"preferred":false,"id":401671,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70024539,"text":"70024539 - 2002 - Nitrate in aquifers beneath agricultural systems","interactions":[],"lastModifiedDate":"2012-03-12T17:20:06","indexId":"70024539","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Nitrate in aquifers beneath agricultural systems","docAbstract":"Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey's NAWOA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and shallow carbonate aquifers provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional nutrient applications. The agricultural system of corn, soybeans, and hogs produced significantly larger concentrations of groundwater nitrate than all other agricultural systems, although mean nitrate concentrations in counties with dairy, poultry, cattle and grains, and horticulture systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as in Asia, may experience the greatest impact of this practice.","largerWorkTitle":"Water Science and Technology","language":"English","issn":"02731223","usgsCitation":"Burkart, M.R., and Stoner, J., 2002, Nitrate in aquifers beneath agricultural systems, in Water Science and Technology, v. 45, no. 9, p. 19-28.","startPage":"19","endPage":"28","numberOfPages":"10","costCenters":[],"links":[{"id":233160,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"45","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a66a1e4b0c8380cd72eb9","contributors":{"authors":[{"text":"Burkart, M. R.","contributorId":42190,"corporation":false,"usgs":true,"family":"Burkart","given":"M.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":401640,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stoner, J.D.","contributorId":58261,"corporation":false,"usgs":true,"family":"Stoner","given":"J.D.","email":"","affiliations":[],"preferred":false,"id":401641,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70024538,"text":"70024538 - 2002 - Potential toxicity of pesticides measured in midwestern streams to aquatic organisms","interactions":[],"lastModifiedDate":"2018-11-28T09:55:48","indexId":"70024538","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3724,"text":"Water Science and Technology","active":true,"publicationSubtype":{"id":10}},"title":"Potential toxicity of pesticides measured in midwestern streams to aquatic organisms","docAbstract":"Society is becoming increasingly aware of the value of healthy aquatic ecosystems as well as the effects that man’s activities have on those ecosystems. In recent years, many urban and industrial sources of contamination have been reduced or eliminated. The agricultural community also has worked towards reducing off-site movement of agricultural chemicals, but their use in farming is still growing. A small fraction, estimated at <1 to 2% of the pesticides applied to crops are lost from fields and enter nearby streams during rainfall events. In many cases aquatic organisms are exposed to mixtures of chemicals, which may lead to greater non-target risk than that predicted based on traditional risk assessments for single chemicals. We evaluated the potential toxicity of environmental mixtures of 5 classes of pesticides using concentrations from water samples collected from ∼50 sites on midwestern streams during late spring or early summer runoff events in 1989 and 1998. Toxicity index values are calculated as the concentration of the compound in the sample divided by the EC50 or LC50 of an aquatic organism. These index values are summed within a pesticide class and for all classes to determine additive pesticide class and total pesticide toxicity indices. Toxicity index values greater than 1.0 indicate probable toxicity of a class of pesticides measured in a water sample to aquatic organisms. Results indicate that some samples had probable toxicity to duckweed and green algae, but few are suspected of having significant toxicity to bluegill sunfish or chorus frogs.
","language":"English","publisher":"IWA Publishing","usgsCitation":"Battaglin, W., and Fairchild, J., 2002, Potential toxicity of pesticides measured in midwestern streams to aquatic organisms: Water Science and Technology, v. 45, no. 9, p. 95-103.","productDescription":"9 p.","startPage":"95","endPage":"103","costCenters":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":233126,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":351866,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://wst.iwaponline.com/content/45/9/95"}],"volume":"45","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a7f65e4b0c8380cd7aae3","contributors":{"authors":[{"text":"Battaglin, W.","contributorId":80388,"corporation":false,"usgs":true,"family":"Battaglin","given":"W.","email":"","affiliations":[],"preferred":false,"id":401639,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fairchild, J.","contributorId":50321,"corporation":false,"usgs":true,"family":"Fairchild","given":"J.","email":"","affiliations":[],"preferred":false,"id":401638,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70024535,"text":"70024535 - 2002 - Historical patterns of river stage and fish communities as criteria for operations of dams on the Illinois river","interactions":[],"lastModifiedDate":"2018-02-23T15:38:59","indexId":"70024535","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3301,"text":"River Research and Applications","active":true,"publicationSubtype":{"id":10}},"title":"Historical patterns of river stage and fish communities as criteria for operations of dams on the Illinois river","docAbstract":"The hydrologic regime of the Illinois River has been altered over the past 100 years. Locks and dams regulate water surface elevations and flow, enabling commercial navigation to continue year round. This study relates changes in water surface elevation to fish abundance in the river, and establishes target criteria for operating locks and dams. Using long-term records of daily river stage, we identified ecologically meaningful hydrological parameters for eight gage locations along the Illinois River. Inter-annual variability of a long-term fisheries dataset beginning in 1957 was related to variability in stage, flood and recession duration, frequency, timing, and rate of change of water levels. Reversals in water surface elevation, maximum stage levels, and length of the spring flood were the most important parameters influencing abundance of age-zero fishes in annual collections. Smallmouth buffalo (Ictiobus bubalus), black crappie (Pomoxis nigromaculatus), freshwater drum (Aplodinotus grunneins), and white bass (Morone chrysops) were most abundant in samples during years that approximated the natural water level regime. Of the 33 hydrologic parameters evaluated for the entire water year from an Illinois River gage site on La Grange Reach, all except average stage in January and Julian date (JD) of maximum stage had moderate or high hydrologic alteration based on the historical range of variation (RVA). The highest degree of hydrologic alteration was for minimum stage levels (1-day, 3-day, and 7-day), rate-of-rise, and rate-of-fall. Other parameters that have been severely altered were 30-day minimum stage, 90-day maximum stage, and the annual number of water level reversals. Operations of the La Grange and Peoria locks and dams could be modified so water level variability would approximate that of the late 1800s, when fish and wildlife resources were abundant. The water regime could be regulated to maintain navigation and improve conditions for native plants and animals without increasing flood damages.
","language":"English","publisher":"Wiley","doi":"10.1002/rra.630","usgsCitation":"Koel, T., and Sparks, R.E., 2002, Historical patterns of river stage and fish communities as criteria for operations of dams on the Illinois river: River Research and Applications, v. 18, no. 1, p. 3-19, https://doi.org/10.1002/rra.630.","productDescription":"17 p.","startPage":"3","endPage":"19","costCenters":[],"links":[{"id":233087,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","otherGeospatial":"Illinois River","volume":"18","issue":"1","noUsgsAuthors":false,"publicationDate":"2002-01-28","publicationStatus":"PW","scienceBaseUri":"505a3195e4b0c8380cd5e045","contributors":{"authors":[{"text":"Koel, Todd M.","contributorId":196920,"corporation":false,"usgs":false,"family":"Koel","given":"Todd M.","affiliations":[],"preferred":false,"id":401612,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sparks, Richard E.","contributorId":39091,"corporation":false,"usgs":false,"family":"Sparks","given":"Richard","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":401613,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70024534,"text":"70024534 - 2002 - Classification of reaches in the Missouri and lower Yellowstone Rivers based on flow characteristics","interactions":[],"lastModifiedDate":"2018-02-23T15:40:07","indexId":"70024534","displayToPublicDate":"2002-01-01T00:00:00","publicationYear":"2002","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3301,"text":"River Research and Applications","active":true,"publicationSubtype":{"id":10}},"title":"Classification of reaches in the Missouri and lower Yellowstone Rivers based on flow characteristics","docAbstract":"Several aspects of flow have been shown to be important determinants of biological community structure and function in streams, yet direct application of this approach to large rivers has been limited. Using a multivariate approach, we grouped flow gauges into hydrologically similar units in the Missouri and lower Yellowstone Rivers and developed a model based on flow variability parameters that could be used to test hypotheses about the role of flow in determining aquatic community structure. This model could also be used for future comparisons as the hydrological regime changes. A suite of hydrological parameters for the recent, post-impoundment period (1 October 1966–30 September 1996) for each of 15 gauges along the Missouri and lower Yellowstone Rivers were initially used. Preliminary graphical exploration identified five variables for use in further multivariate analyses. Six hydrologically distinct units composed of gauges exhibiting similar flow characteristics were then identified using cluster analysis. Discriminant analyses identified the three most influential variables as flow per unit drainage area, coefficient of variation of mean annual flow, and flow constancy. One surprising result was the relative similarity of flow regimes between the two uppermost and three lowermost gauges, despite large differences in magnitude of flow and separation by roughly 3000 km. Our results synthesize, simplify and interpret the complex changes in flow occurring along the Missouri and lower Yellowstone Rivers, and provide an objective grouping for future tests of how these changes may affect biological communities.
","language":"English","publisher":"Wiley","doi":"10.1002/rra.635","usgsCitation":"Pegg, M.A., and Pierce, C.L., 2002, Classification of reaches in the Missouri and lower Yellowstone Rivers based on flow characteristics: River Research and Applications, v. 18, no. 1, p. 31-42, https://doi.org/10.1002/rra.635.","productDescription":"12 p.","startPage":"31","endPage":"42","costCenters":[],"links":[{"id":233054,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","otherGeospatial":"Missouri River, Yellowstone River","volume":"18","issue":"1","noUsgsAuthors":false,"publicationDate":"2002-01-28","publicationStatus":"PW","scienceBaseUri":"5059f61ce4b0c8380cd4c5cd","contributors":{"authors":[{"text":"Pegg, Mark A.","contributorId":198830,"corporation":false,"usgs":false,"family":"Pegg","given":"Mark","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":401610,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Pierce, Clay L. cpierce@usgs.gov","contributorId":525,"corporation":false,"usgs":true,"family":"Pierce","given":"Clay","email":"cpierce@usgs.gov","middleInitial":"L.","affiliations":[{"id":350,"text":"Iowa Cooperative Fish and Wildlife Research Unit","active":false,"usgs":true}],"preferred":false,"id":401611,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}