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Sample records for lake michigan sediment

  1. Plutonium and americium in Lake Michigan sediments

    International Nuclear Information System (INIS)

    Edgington, D.N.; Alberts, J.J.; Wahlgren, M.A.; Karttunen, J.O.; Reeve, C.A.

    1975-01-01

    The vertical distributions of 239 , 240 Pu, 238 Pu, and 137 Cs have been measured in sediment cores taken from Lake Michigan. Sections from a limited number of cores have been analyzed for 241 Am. In addition, grab samples from ten locations in the southern basin of the lake have been analyzed for phase distribution of 239 , 240 Pu using a sequential extraction technique. The results indicate that the 239 , 240 Pu, 238 Pu, and 137 Cs from weapons testing, and the 241 Am formed in situ are concentrated in the sediments. A comparison of the total deposition of 239 , 240 Pu and 137 Cs indicates that 137 Cs may be valuable as a monitor for 239 , 240 Pu deposition in the sediments. Values of the 238 Pu/ 239 , 240 Pu ratio are in agreement with values reported in Lake Ontario sediments (and Lake Michigan plankton) and show little variation with depth. 241 Am data support the concept of in situ production with little preferential mobility after formation. Studies of sedimentary phase distributions show that 239 , 240 Pu is associated with hydrous oxide phases which are chemically stable under the prevailing conditions in lake sediments. Since Lake Michigan sediments remain aerobic, relatively little 239 , 240 Pu is available for chemical mobilization from the hydrous oxide or organic phases present in the sediments

  2. Total and methyl mercury, moisture, and porosity in Lake Michigan surficial sediment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Total and methyl mercury, moisture content (%), and porosity were measured in Lake Michigan sediment by the U.S. Environmental Protection Agency/Office of Research...

  3. Stable lead geochronology of fine-grained sediments in Southern Lake Michigan

    International Nuclear Information System (INIS)

    Robbins, J.A.; Edgington, D.N.

    1974-01-01

    In a previous article, it was shown that the vertical distribution of stable lead in the fine-grained sediments of Lake Michigan reflects the history of cultural lead inputs. It was found that the lead distributions in dated cores are quantitatively described by a universal time-dependent loading or source function which is a linear combination of estimated annual inputs of atmospheric lead derived from the combustion of leaded gasoline and the burning of coal in and around Chicago since about 1800. The existence of such a source function for lead implies that stable lead itself may be used to date sediment cores. Mercury depth profiles in western Lake Erie sediments have shown several horizons which correspond to the development of local industrial use of mercury over the past forty years or so. The construction of the lead source function for Lake Michigan sediments was based on only four lead-210 dated cores. To establish the validity of the source function concept, it is applied to the distribution of lead determined in many cores previously obtained from southern Lake Michigan

  4. Sedimentological and mineralogical characteristics of recent sediments at selected sites in the southern basin of Lake Michigan

    International Nuclear Information System (INIS)

    Tisue, G.T.; Merk, G.

    1976-01-01

    During the 1976 field season, sediment traps and current meters were set out in the southern basin of Lake Michigan to study the relationship between suspended material and currents. The gross mineralogical and chemical characteristics of the bottom sediments at the locations of these experiments were determined

  5. Bathymetry of Lake Michigan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Michigan has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  6. Lake Michigan sediments: in-situ tracer measurements using a rare-earth element

    International Nuclear Information System (INIS)

    Krezoski, J.R.

    1985-01-01

    A rare-earth-element (REE) tracer technique is used to describe in-situ biogenic and physical sediment reworking in Green Bay, Lake Michigan. Europium, a stable, high neutron capture cross section REE, added as Eu 2 O 3 to the sediment-water interface of quadrants of natural bottom muds, served as a tracer of surficial sediment redistribution in an oligochaete-chironomid-sphaerid benthic community. Sixty days after applying a millimeter thick layer of Eu to the undisturbed sediments, divers collected cores from within and around the experimental quadrants that were sectioned in 1 cm intervals to 10 cm and were analyzed by neutron activation analysis. Minute amounts of the activated REE in the sediment, detectable through high resolution gamma spectroscopy, revealed significant burial (to 2.4 cm) and broadening of the marked layer. A calculated bio-diffusion coefficient (K/sub B/ = 2.26 +/- 1.56 x 10 -6 cm 2 sec -1 ), based on a model from earlier microcosm studies, compares remarkably well with experimentally determined values and represents the first application of this model to field data. The method provides reliable estimates of in-situ reworking rates and is more accurate than time-averaged geochronology studies which rely on atmospherically derived radionuclides

  7. Whiting in Lake Michigan

    Science.gov (United States)

    2002-01-01

    Satellites provide a view from space of changes on the Earth's surface. This series of images from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) aboard the Orbview-2 satellite shows the dramatic change in the color of Lake Michigan during the summer. The bright color that appears in late summer is probably caused by calcium carbonate-chalk-in the water. Lake Michigan always has a lot of calcium carbonate in it because the floor of the lake is limestone. During most of the year the calcium carbonate remains dissolved in the cold water, but at the end of summer the lake warms up, lowering the solubility of calcium carbonate. As a result, the calcium carbonate precipitates out of the water, forming clouds of very small solid particles that appear as bright swirls from above. The phenomenon is appropriately called a whiting event. A similar event occured in 1999, but appears to have started later and subsided earlier. It is also possible that a bloom of the algae Microcystis is responsible for the color change, but unlikely because of Lake Michigan's depth and size. Microcystis blooms have occured in other lakes in the region, however. On the shore of the lake it is possible to see the cities of Chicago, Illinois, and Milwaukee, Wisconsin. Both appear as clusters of gray-brown pixels. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  8. Recent geologic development of Lake Michigan (U.S.A.)

    Science.gov (United States)

    Gross, D.L.; Cahill, R.A.

    1983-01-01

    The stresses placed on Lake Michigan since the advent of industrialization require knowledge of the sedimentology of the whole lake in order to make informed decisions for environmental planning. Sediment accumulation rates are low: areas of the lake receiving the most sediment average only 1 mm a-1; deep-water basins average 0.1 to 0.5 mm a-1; and large areas are not receiving any sediment. Sediment was deposited rapidly (typically 5 mm a-1), in the form of rock flour, during the deglaciation of both Lake Michigan and Lake Superior Basins. Then the rate of accumulation decreased by 80-90% and has remained relatively constant since final deglaciation. Because active sedimentation occurs mostly in the deep water areas of the lake, the sediment remains undisturbed and contains a record of the chemical history of the lake. ?? 1983 Dr W. Junk Publishers.

  9. A reactive nitrogen budget for Lake Michigan

    Science.gov (United States)

    The reactive nitrogen budget for Lake Michigan was reviewed and updated, making use of recent estimates of watershed and atmospheric nitrogen loads. The updated total N load to Lake Michigan was approximately double the previous estimate from the Lake Michigan Mass Balance study ...

  10. Pollutant transformations over Lake Michigan

    International Nuclear Information System (INIS)

    Alkezweeny, A.J.; Arbuthnot, D.R.; Busness, K.M.; Easter, R.C.; Hales, J.M.; Lee, R.N.; Young, J.M.

    1979-01-01

    An aircraft, a chartered boat, and a constant altitude balloon were used to study pollutant transformations over Lake Michigan in a Lagrangian frame of reference. The experiments were conducted during the summer under strong atmospheric stability where diffusion and dry deposition of pollutants can be neglected

  11. Environmental status of the Lake Michigan region. Volume 6. Zoobenthos of Lake Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Mozley, S.C.; Howmiller, R.P.

    1977-09-01

    This report summarizes Lake Michigan zoobenthic studies up to 1974, including reports of power-plant surveys. It describes ecologies of macroinvertebrate species and some microfauna, partly through use of data from other Great Lakes. The following are discussed: methodology of field surveys; zoobenthic indicators of pollution; zoobenthic effects on sediment-water exchanges; and numbers, biomass, and production of total macroinvertebrates. Prominent features of Lake Michigan zoobenthos include predominance of the amphipod Pontoporeia affinis, usefulness of tubificid oligochaetes in mapping environmental quality, and pronounced qualitative gradients in zoobenthos in relation to depth. Further research is needed on sampling methods, energy flow rates and pathways through benthic communities, factors limiting distribution of species near shore, and effects of macroinvertebrates on sediment chemistry and structure.

  12. Environmental status of the Lake Michigan region. Volume 3. Chemistry of Lake Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Torrey, M S

    1976-05-01

    The report is a synoptic review of data collected over the past twenty years on the chemistry of Lake Michigan. Changes in water quality and sediment chemistry, attributable to cultural and natural influences, are considered in relation to interacting processes and factors controlling the distribution and concentration of chemical substances within the Lake. Temperature, light, and mixing processes are among the important natural influences that affect nutrient cycling, dispersal of pollutants, and fate of materials entering the Lake. Characterization of inshore-offshore and longitudinal differences in chemical concentrations and sediment chemistry for the main body of the Lake is supplemented by discussion of specific areas such as Green Bay and Grand Traverse Bay. Residues, specific conductance, dissolved oxygen, major and trace nutrients, and contaminants are described in the following context: biological essentiality and/or toxicity, sources to the Lake, concentrations in the water column and sediments, chemical forms, seasonal variations and variation with depth. A summary of existing water quality standards, statutes, and criteria applicable to Lake Michigan is appended.

  13. Areal distribution and concentration of contaminants of concern in surficial streambed and lakebed sediments, Lake St. Clair and tributaries, Michigan, 1990-2003

    Science.gov (United States)

    Rachol, Cynthia M.; Button, Daniel T.

    2006-01-01

    were collected throughout the lake. The distribution of trace-element concentrations corresponded well with the results of a two-dimensional hydrodynamic model of flow patterns from the Clinton River into Lake St. Clair. The model was developed independent from the bed sediment analysis described in this report; yet it showed a zone of deposition for outflow from the Clinton River into Lake St. Clair that corresponded well with the spatial distribution of trace-element concentrations. This zone runs along the western shoreline of Lake St. Clair from L'Anse Creuse Bay to St. Clair Shores, Michigan and is reflected in the samples analyzed for mercury and cadmium.Statistical summaries of the concentration data are presented for most contaminants, and selected statistics are compared to effects-based sediment-quality guidelines. Summaries were not computed for dieldrin, chlordane, hexachlorocyclohexane, lindane, and mirex because insufficient data are available for these contaminants. A statistical comparison showed that the median concentration for hexachlorobenzene, anthracene, benz[a]anthracene, chrysene, and pyrene are greater than the Threshold Effect Concentration or Lowest Effect Level.Probable Effect Concentration Quotients provide a mechanism for comparing the concentrations of contaminant mixtures against effects-based biota data. Probable Effect Concentration Quotients were calculated for individual samples and compared to effects-based toxicity ranges. The toxicity-range categories used in this study were nontoxic (quotients 0.5). Of the 546 individual samples for which Probable Effect Concentration Quotients were calculated, 469 (86 percent) were categorized as being nontoxic and 77 (14 percent) were categorized as being toxic. Bed-sediment samples with toxic Probable Effect Concentration Quotients were collected from Paint Creek, Galloway Creek, the main stem of the Clinton River, Big Beaver Creek, Red Run, Clinton River towards the mouth, Lake St. Clair

  14. Lake Michigan lake trout PCB model forecast post audit

    Science.gov (United States)

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents th...

  15. Fish impingement at Lake Michigan power plants

    International Nuclear Information System (INIS)

    Sharma, R.K.; Freeman, R.F.; Spigarelli, S.A.

    1976-01-01

    A study was initiated in 1974 to survey the magnitude and to evaluate the impact of fish impingement at 20 power plants on the Great Lakes. Data on impingement rates, site characteristics, intake designs and operational features have been collected and analyzed. Interpretive analyses of these data are in progress. The objectives of this study were: to summarize fish impingement data for Lake Michigan (16/20 plants surveyed are on Lake Michigan); to assess the significance of total and source-related mortalities on populations of forage and predator species; and to expand the assessment of power plant impingement to include all water intakes on Lake Michigan. Data are tabulated

  16. 137Cs as a tracer of recent sedimentary processes in Lake Michigan

    Science.gov (United States)

    Cahill, R.A.; Steele, J.D.

    1986-01-01

    To determine recent sediment movement, we measured the levels of 137Cs (an artificial radionuclide produced during nuclear weapons testing) of 118 southern Lake Michigan samples and 27 in Green Bay. These samples, taken from 286 grab samples of the upper 3 cm of sediment, were collected in 1975 as part of a systematic study of Lake Michigan sediment. 137Cs levels correlated well with concentrations of organic carbon, lead, and other anthropogenic trace metals in the sediment. 137Cs had a higher correlation with silt-sized than with clay-sized sediment (0.55 and 0.46, respectively). Atmospherically derived 137Cs and trace metals are being redistributed by sedimentary processes in Lake Michigan after being incorporated in suspended sediment. We determined a distribution pattern of 137Cs that represents areas of southern Lake Michigan where sediment deposition is occurring. ?? 1986 Dr W. Junk Publishers.

  17. Lake-wide distribution of Dreissena in Lake Michigan, 1999

    Science.gov (United States)

    Fleischer, Guy W.; DeSorcie, Timothy J.; Holuszko, Jeffrey D.

    2001-01-01

    The Great Lakes Science Center has conducted lake-wide bottom trawl surveys of the fish community in Lake Michigan each fall since 1973. These systematic surveys are performed at depths of 9 to 110 m at each of seven index sites around Lake Michigan. Zebra mussel (Dreissena polymorpha) populations have expanded to all survey locations and at a level to sufficiently contribute to the bottom trawl catches. The quagga (Dreissena bugensis), recently reported in Lake Michigan, was likely in the catches though not recognized. Dreissena spp. biomass ranged from about 0.6 to 15 kg/ha at the various sites in 1999. Dreissenid mussels were found at depths of 9 to 82 m, with their peak biomass at 27 to 46 m. The colonization of these exotic mussels has ecological implications as well as potential ramifications on the ability to sample fish consistently and effectively with bottom trawls in Lake Michigan.

  18. Mapping Lake Michigan Fish Catch Data

    OpenAIRE

    Wodd, Jacob; Doucette, Jarrod; Höök, Tomas O.

    2014-01-01

    The only Great Lake completely contained in the U.S., Lake Michigan offers an abundance of recreational fishing. This project takes 20 years’ worth of salmonid fish catch data, and uses GIS to organize and visually represent the data in a way that is meaningful and helpful to local fisherman and researchers. Species represented included Brown Trout, Lake Trout, Rainbow Trout, Chinook Salmon, and Coho Salmon. The species are organized by both decadal and yearly spans, as well as catch per t...

  19. Surficial geologic map of Berrien County, Michigan, and the adjacent offshore area of Lake Michigan

    Science.gov (United States)

    Stone, Byron D.; Kincare, Kevin A.; O'Leary, Dennis W.; Newell, Wayne L.; Taylor, Emily M.; Williams, Van S.; Lundstrom, Scott C.; Abraham, Jared E.; Powers, Michael H.

    2017-12-13

    The surficial geologic map of Berrien County, southwestern Michigan (sheet 1), shows the distribution of glacial and postglacial deposits at the land surface and in the adjacent offshore area of Lake Michigan. The geologic map differentiates surficial materials of Quaternary age on the basis of their lithologic characteristics, stratigraphic relationships, and age. Drill-hole information correlated in cross sections provides details of typical stratigraphic sequences that compose one or more penetrated geologic map units. A new bedrock geologic map (on sheet 2) includes contours of the altitude of the eroded top of bedrock and shows the distribution of middle Paleozoic shale and carbonate units in the subcrop. A sediment thickness map (also on sheet 2) portrays the extent of as much as 150 meters of surficial materials that overlie the bedrock surface.The major physical features of the county are related principally to deposits of the last Laurentide ice sheet that advanced and then retreated back through the region from about 19,000 to 14,000 radiocarbon years before present. Glacial and postglacial deposits underlie the entire county; shale bedrock crops out only in the adjacent offshore area on the bottom of Lake Michigan. All glacial deposits and glacial meltwater deposits in Berrien County are related to the late Wisconsinan glacial advances of the Lake Michigan ice lobe and its three regional recessional moraines, which cross the county as three north-northeast-trending belts.From east to west (oldest to youngest), the three moraine belts are known as the Kalamazoo, Valparaiso, and Lake Border morainic systems. The till-ridge morainic systems (Lake Border and local Valparaiso morainic systems) consist of multiple, elongate moraine ridges separated by till plains and lake-bottom plains. Tills in ground and end moraines in Berrien County are distinguished as informal units, and are correlated with three proposed regional till units in southwestern Michigan

  20. Synthetic musk fragrances in Lake Michigan.

    Science.gov (United States)

    Peck, Aaron M; Hornbuckle, Keri C

    2004-01-15

    Synthetic musk fragrances are added to a wide variety of personal care and household products and are present in treated wastewater effluent. Here we report for the first time ambient air and water measurements of six polycyclic musks (AHTN, HHCB, ATII, ADBI, AHMI, and DPMI) and two nitro musks (musk xylene and musk ketone) in North America. The compounds were measured in the air and water of Lake Michigan and in the air of urban Milwaukee, WI. All of the compounds except DPMI were detected. HHCB and AHTN were found in the highest concentrations in all samples. Airborne concentrations of HHCB and AHTN average 4.6 and 2.9 ng/m3, respectively, in Milwaukee and 1.1 and 0.49 ng/m3 over the lake. The average water concentration of HHCB and AHTN in Lake Michigan was 4.7 and 1.0 ng/L, respectively. A lake-wide annual mass budget shows that wastewater treatment plant discharge is the major source (3470 kg/yr) of the synthetic musks while atmospheric deposition contributes less than 1%. Volatilization and outflow through the Straits of Mackinac are major loss mechanisms (2085 and 516 kg/yr for volatilization and outflow, respectively). Concentrations of HHCB are about one-half the predicted steady-state water concentrations in Lake Michigan.

  1. Lethal and sublethal responses to a sediment bound toxicant by two oligochaetes from Lake Michigan: stylodrilus heringianus and limnodrilus hoffmeisteri

    International Nuclear Information System (INIS)

    Keilty, T.J.

    1987-01-01

    Short-term lethal, and short and long-term sublethal responses by Stylodrilus heringianus (Lumbriculidae) and Limnodrilus hoffmeisteri (Tubificidae) to sediments dosed with endrin were measured in single and mixed species tests. Ninety-six hour LC 50 values were 2588 +/- 1974 and 2757 +/- 995 ug/g dry weight sediment for S. heringianus and L. hoffmeisteri respectively. Ninety-six hour EC 50 burrowing avoidance values (concentration where 50% do not burrow) were one to two orders of magnitude lower than the LC 50 's. Short-term mixed species LC 50 data suggested that L. hoffmeisteri may benefit from the presence of S. heringianus. Long-term sublethal responses were quantified by measuring sediment reworking rates (the rate at which subsurface sediments are egested at the surface and re-buried) in laboratory microcosms. Rates were determined by monitoring a gamma-emitting 137 Cesium marker layer with a well-collimated NaI detector. Sediment endrin concentrations ranged from 3 ng/g to 82 ug/g in six 1300 hour experiments. For S. heringianus, reworking rates were stimulated at low concentrations during the first half of experiments, followed by gradual decreases relative to controls. Stimulation of L. hoffmeisteri reworking was not observed. At high concentrations, early reworking rates were reduced for both species, followed by dramatic decreases later on. In mixed species experiments at high concentrations, the presence of S. heringianus enhanced the reworking of L. hoffmeisteri, although the reverse was not observed. Decreased mortality and increased post experimental dry weights of L. hoffmeisteri in mixed, relative to single species tests were also observed. Generally, post experimental worm weights were inversely related to sediment endrin loads, and bioconcentration factors for S. heringianus (10-40) were approximately fourfold that of L. hoffmeisteri (1-10)

  2. Recruitment variability of alewives in Lake Michigan

    Science.gov (United States)

    Madenjian, C.P.; Hook, T.O.; Rutherford, E.S.; Mason, D.M.; Croley, T.E.; Szalai, E.B.; Bence, J.R.

    2005-01-01

    We used a long-term series of observations on alewife Alosa pseudoharengus abundance that was based on fall bottom-trawl catches to assess the importance of various abiotic and biotic factors on alewife recruitment in Lake Michigan during 1962–2002. We first fit a basic Ricker spawner–recruit model to the lakewide biomass estimates of age-3 recruits and the corresponding spawning stock size; we then fit models for all possible combinations of the following four external variables added to the basic model: an index of salmonine predation on an alewife year-class, an index for the spring–summer water temperatures experienced by alewives during their first year in the lake, an index of the severity of the first winter experienced by alewives in the lake, and an index of lake productivity during an alewife year-class's second year in the lake. Based on an information criterion, the best model for alewife recruitment included indices of salmonine predation and spring–summer water temperatures as external variables. Our analysis corroborated the contention that a decline in alewife abundance during the 1970s and early 1980s in Lake Michigan was driven by salmonine predation. Furthermore, our findings indicated that the extraordinarily warm water temperatures during the spring and summer of 1998 probably led to a moderately high recruitment of age-3 alewives in 2001, despite abundant salmonines.

  3. 27 CFR 9.79 - Lake Michigan Shore.

    Science.gov (United States)

    2010-04-01

    ... Michigan Shore. (a) Name. The name of the viticultural area described in this section is “Lake Michigan... southeast along the winding course of the Kalamazoo River for approximately 35 miles until it intersects the...

  4. Lake Michigan Offshore Wind Feasibility Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Boezaart, Arnold [GVSU; Edmonson, James [GVSU; Standridge, Charles [GVSU; Pervez, Nahid [GVSU; Desai, Neel [University of Michigan; Williams, Bruce [University of Delaware; Clark, Aaron [GVSU; Zeitler, David [GVSU; Kendall, Scott [GVSU; Biddanda, Bopi [GVSU; Steinman, Alan [GVSU; Klatt, Brian [Michigan State University; Gehring, J. L. [Michigan State University; Walter, K. [Michigan State University; Nordman, Erik E. [GVSU

    2014-06-30

    The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the

  5. Post Audit of Lake Michigan Lake Trout PCB Model Forecasts

    Science.gov (United States)

    The Lake Michigan (LM) Mass Balance Study was conducted to measure and model polychlorinated biphenyls (PCBs) and other anthropogenic substances to gain a better understanding of the transport, fate, and effects of these substances within the system and to aid managers in the env...

  6. Study of the behaviour of transuranics and possible chemical homologues in Lake Michigan water and biota

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Alberts, J.J.; Nelson, D.M.; Orlandini, K.A.

    1976-01-01

    Concentration factors for Pu, Am and U in Lake Michigan biota are compared to those of a number of stable trace elements that have short residence times in Lake Michigan water. The relative order of uptake for these nuclides in Lake Michigan biota is Am>Pu much>U. Evidence is summarized which suggests that the predominant oxidation state of 239 , 240 Pu in Lake Michigan water is 4+. Concentrations of 239 , 240 Pu in net plankton, filterable particulate matter, sediment trap, and benthic floc samples indicate that sorption by biogenic detritus, and settling of this material, can account for the reduced concentration of 239 , 240 Pu observed in surface waters during summer stratification, but that deposition into the sediments is primarily non-biological. Concentrations of 7 Be, 144 Ce and 137 Cs in sediment trap samples show the effect of spring convective mixing and demonstrate the resuspension of mineral-rich surficial sediments during the summer months. The effect on the concentration of dissolved plutonium in the water column, of varying degrees of resuspension of sedimentary floc, is described using a simple mass-action model. A radiochemical method for the determination of americium and uranium in Lake Michigan environmental samples is also presented. (author)

  7. Comparative analysis of discharges into Lake Michigan, Phase I - Southern Lake Michigan.

    Energy Technology Data Exchange (ETDEWEB)

    Veil, J. A.; Elcock, D.; Gasper, J. R.; Environmental Science Division

    2008-06-30

    BP Products North America Inc. (BP) owns and operates a petroleum refinery located on approximately 1,700 acres in Whiting, East Chicago, and Hammond, Indiana, near the southern tip of Lake Michigan. BP provided funding to Purdue University-Calumet Water Institute (Purdue) and Argonne National Laboratory (Argonne) to conduct studies related to wastewater treatment and discharges. Purdue and Argonne are working jointly to identify and characterize technologies that BP could use to meet the previous discharge permit limits for total suspended solids (TSS) and ammonia after refinery modernization. In addition to the technology characterization work, Argonne conducted a separate project task, which is the subject of this report. In Phase I of a two-part study, Argonne estimated the current levels of discharge to southern Lake Michigan from significant point and nonpoint sources in Illinois, Indiana, and portions of Michigan. The study does not consider all of the chemicals that are discharged. Rather, it is narrowly focused on a selected group of pollutants, referred to as the 'target pollutants'. These include: TSS, ammonia, total and hexavalent chromium, mercury, vanadium, and selenium. In Phase II of the study, Argonne will expand the analysis to cover the entire Lake Michigan drainage basin.

  8. Energy density of lake whitefish Coregonus clupeaformis in Lakes Huron and Michigan

    Science.gov (United States)

    Pothoven, S.A.; Nalepa, T.F.; Madenjian, C.P.; Rediske, R.R.; Schneeberger, P.J.; He, J.X.

    2006-01-01

    We collected lake whitefish Coregonus clupeaformis off Alpena and Tawas City, Michigan, USA in Lake Huron and off Muskegon, Michigan USA in Lake Michigan during 2002–2004. We determined energy density and percent dry weight for lake whitefish from both lakes and lipid content for Lake Michigan fish. Energy density increased with increasing fish weight up to 800 g, and then remained relatively constant with further increases in fish weight. Energy density, adjusted for weight, was lower in Lake Huron than in Lake Michigan for both small (≤800 g) and large fish (>800 g). Energy density did not differ seasonally for small or large lake whitefish or between adult male and female fish. Energy density was strongly correlated with percent dry weight and percent lipid content. Based on data from commercially caught lake whitefish, body condition was lower in Lake Huron than Lake Michigan during 1981–2003, indicating that the dissimilarity in body condition between the lakes could be long standing. Energy density and lipid content in 2002–2004 in Lake Michigan were lower than data for comparable sized fish collected in 1969–1971. Differences in energy density between lakes were attributed to variation in diet and prey energy content as well as factors that affect feeding rates such as lake whitefish density and prey abundance.

  9. Lake Michigan lake trout PCB model forecast post audit (oral presentation)

    Science.gov (United States)

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents an...

  10. Thermal discharge residence by Lake Michigan Salmonids

    International Nuclear Information System (INIS)

    Romberg, G.P.; Prepejchal, W.

    1975-01-01

    Lake Michigan salmon and trout were tagged with a thermoluminescent dosimeter (TLD) temperature tag to estimate their thermal exposure and residence time at a warm water discharge. Fish were collected, tagged, and released at the Point Beach Nuclear Plant, Two Rivers, Wisconsin, in the fall of 1973 and 1974. Tags were recovered during the same season, primarily from fish recaptured at Point Beach. Average uniform temperature exposure and maximum possible discharge residence time were determined. Appropriate hourly intake and discharge temperatures were averaged to calculate mean temperature exposure for the case of maximum discharge residence. Lowest discharge temperature not included within the period of maximum residence was identified to serve as a possible indicator of avoidance temperature. Mean values for the above parameters were calculated for fish species for each tagging year and are reported with the accompanying range of intake and discharge temperatures

  11. A post-Calumet shoreline along southern Lake Michigan

    Science.gov (United States)

    Capps, D.K.; Thompson, T.A.; Booth, R.K.

    2007-01-01

    The southern shore of Lake Michigan is the type area for many of ancestral Lake Michigan's late Pleistocene lake phases, but coastal deposits and features of the Algonquin phase of northern Lake Michigan, Lake Huron, and Lake Superior are not recognized in the area. Isostatic rebound models suggest that Algonquin phase deposits should be 100 m or more below modern lake level. A relict shoreline, however, exists along the lakeward margin of the Calumet Beach that was erosional west of Deep River and depositional east of the river. For this post-Calumet shoreline, the elevation of basal foreshore deposits east of Deep River and the base of the scarp west of Deep River indicate a slightly westward dipping water plane that is centered at ???184 m above mean sea level. Basal foreshore elevations also indicate that lake level fell ???2 m during the development of the shoreline. The pooled mean of radiocarbon dates from the surface of the peat below post-Calumet shoreline foreshore deposits indicate that the lake transgressed over the peat at 10,560 ?? 70 years B.P. Pollen assemblages from the peat are consistent with this age. The elevation and age of the post-Calumet shoreline are similar to the Main Algonquin phase of Lake Huron. Recent isostatic rebound models do not adequately address a high-elevation Algonquin-age shoreline along the southern shore of Lake Michigan, but the Goldthwait (1908) hinge-line model does. ?? 2006 Springer Science+Business Media B.V.

  12. Lake Michigan Fish Acoustic Data from 2011 to 2016

    Data.gov (United States)

    Department of the Interior — Each line in the file “Lake Michigan fish acoustic data from 2011 to 2016.csv” represents the acoustic data and estimated fish density for a single depth layer of...

  13. Environmental status of the Lake Michigan region. Volume 14. Birds of the Lake Michigan drainage basin

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, G.J.

    1977-07-01

    This report characterizes the bird life found in 100 counties of the four states peripheral to Lake Michigan. It discusses major habitats (the Lake Michigan shoreline, inland lakes, rivers and streams, marshes, fields and open spaces, and woodlots) and associates specific birds with habitats according to preferences for space and food. It also discusses the special attributes of state parks and lakeshores, refuges and sanctuaries, and other special areas which are attractive to avifauna. Patterns of historical occurrence and abundance, and the influence of pesticides and pollution, disease, and hunting pressure are explored to place present occurrence in a modern perspective. Migration patterns are discussed to explain increases and decreases which occur in nonresident avifauna of the Basin. The distribution and habits of birds that occur regularly in the Basin are described in an annotated list; a more complete list is presented in a table which encapsulates data for rapid and convenient reference. Separate sections deal with extinct, extirpated, and introduced species, and with endangered, threatened, and declining species.

  14. Acid rain stimulation of Lake Michigan phytoplankton growth

    Science.gov (United States)

    Manny, Bruce A.; Fahnenstiel, G.L.; Gardner, W.S.

    1987-01-01

    Three laboratory experiments demonstrated that additions of rainwater to epilimnetic lake water collected in southeastern Lake Michigan stimulated chlorophyll a production more than did additions of reagent-grade water during incubations of 12 to 20 d. Chlorophyll a production did not begin until 3–5 d after the rain and lake water were mixed. The stimulation caused by additions of rain acidified to pH 3.0 was greater than that caused by additions of untreated rain (pH 4.0–4.5). Our results support the following hypotheses: (1) Acid rain stimulates the growth of phytoplankton in lake water; (2) phosphorus in rain appears to be the factor causing this stimulation. We conclude that acid rain may accelerate the growth of epilimnetic phytoplankton in Lake Michigan (and other similar lakes) during stratification when other sources of bioavailable phosphorus to the epilimnion are limited

  15. Paleosecular variations from lake sediments

    International Nuclear Information System (INIS)

    Lund, S.P.; Banerjee, S.K.

    1979-01-01

    Data are presented on the secular variations of the magnetization of wet and dry lake sediments for 17 North American locations. The usefullness of this data in terms of the geomagnetic field is discussed

  16. Radiocarbon dating of lake sediments

    OpenAIRE

    Pocevičius, Matas

    2016-01-01

    Matas Pocevičius, Radiocarbon dating of lake sediments, bachelor thesis, Vilnius University, Faculty of Physics, Department of General Physics and Spectroscopy, physics, Vilnius, 45 p., 2016. The aim of this study is to evaluate the possibility of radiocarbon dating application for Tapeliai lake bottom sediments. The literature review discusses topics related to accelerator mass spectrometry, principles of radiocarbon formation, importance of nuclear fallout for 14C, possible applications of ...

  17. Mid Holocene lake level and shoreline behavior during the Nipissing phase of the upper Great Lakes at Alpena, Michigan, USA

    Science.gov (United States)

    Thompson, T.A.; Lepper, K.; Endres, A.L.; Johnston, J.W.; Baedke, S.J.; Argyilan, E.P.; Booth, R.K.; Wilcox, D.A.

    2011-01-01

    The Nipissing phase was the last pre-modern high-water stage of the upper Great Lakes. Represented as either a one- or two-peak highstand, the Nipissing occurred following a long-term lake-level rise. This transgression was primarily an erosional event with only the final stage of the transgression preserved as barriers, spits, and strandplains of beach ridges. South of Alpena, Michigan, mid to late Holocene coastal deposits occur as a strandplain between Devils Lake and Lake Huron. The landward part of this strandplain is a higher elevation platform that formed during the final stage of lake-level rise to the Nipissing peak. The pre-Nipissing shoreline transgressed over Devils Lake lagoonal deposits from 6.4 to 6.1. ka. The first beach ridge formed ~ 6. ka, and then the shoreline advanced toward Lake Huron, producing beach ridges about every 70. years. This depositional regression produced a slightly thickening wedge of sediment during a lake-level rise that formed 20 beach ridges. The rise ended at 4.5. ka at the Nipissing peak. This peak was short-lived, as lake level fell > 4. m during the following 500. years. During this lake-level rise and subsequent fall, the shoreline underwent several forms of shoreline behavior, including erosional transgression, aggradation, depositional transgression, depositional regression, and forced regression. Other upper Great Lakes Nipissing platforms indicate that the lake-level change observed at Alpena of a rapid pre-Nipissing lake-level rise followed by a slower rise to the Nipissing peak, and a post-Nipissing rapid lake-level fall is representative of mid Holocene lake level in the upper Great Lakes. ?? 2011 Elsevier B.V.

  18. 76 FR 13508 - Ninth Coast Guard District Sector Realignment; Northern Lake Michigan and Lake Huron

    Science.gov (United States)

    2011-03-14

    ... Station Alpena from Group Sault Ste. Marie to Sectors Lake Michigan and Detroit, respectively. That... boundary adjustment is that Stations Charlevoix and Alpena will be reassigned to Sector Sault Ste. Marie...

  19. Geomorphic and sedimentologic evidence for the separation of Lake Superior from Lake Michigan and Huron

    Science.gov (United States)

    Johnston, J.W.; Thompson, T.A.; Wilcox, D.A.; Baedke, S.J.

    2007-01-01

    A common break was recognized in four Lake Superior strandplain sequences using geomorphic and sedimentologic characteristics. Strandplains were divided into lakeward and landward sets of beach ridges using aerial photographs and topographic surveys to identify similar surficial features and core data to identify similar subsurface features. Cross-strandplain, elevation-trend changes from a lowering towards the lake in the landward set of beach ridges to a rise or reduction of slope towards the lake in the lakeward set of beach ridges indicates that the break is associated with an outlet change for Lake Superior. Correlation of this break between study sites and age model results for the strandplain sequences suggest that the outlet change occurred sometime after about 2,400 calendar years ago (after the Algoma phase). Age model results from one site (Grand Traverse Bay) suggest an alternate age closer to about 1,200 calendar years ago but age models need to be investigated further. The landward part of the strandplain was deposited when water levels were common in all three upper Great Lakes basins (Superior, Huron, and Michigan) and drained through the Port Huron/Sarnia outlet. The lakeward part was deposited after the Sault outlet started to help regulate water levels in the Lake Superior basin. The landward beach ridges are commonly better defined and continuous across the embayments, more numerous, larger in relief, wider, have greater vegetation density, and intervening swales contain more standing water and peat than the lakeward set. Changes in drainage patterns, foreshore sediment thickness and grain size help in identifying the break between sets in the strandplain sequences. Investigation of these breaks may help identify possible gaps in the record or missing ridges in strandplain sequences that may not be apparent when viewing age distributions and may justify the need for multiple age and glacial isostatic adjustment models. ?? 2006 Springer Science

  20. Body burdens of heavy metals in Lake Michigan wetland turtles.

    Science.gov (United States)

    Smith, Dayna L; Cooper, Matthew J; Kosiara, Jessica M; Lamberti, Gary A

    2016-02-01

    Tissue heavy metal concentrations in painted (Chrysemys picta) and snapping (Chelydra serpentina) turtles from Lake Michigan coastal wetlands were analyzed to determine (1) whether turtles accumulated heavy metals, (2) if tissue metal concentrations were related to environmental metal concentrations, and (3) the potential for non-lethal sampling techniques to be used for monitoring heavy metal body burdens in freshwater turtles. Muscle, liver, shell, and claw samples were collected from painted and snapping turtles and analyzed for cadmium, chromium, copper, iron, lead, magnesium, manganese, and zinc. Turtle tissues had measurable quantities of all eight metals analyzed. Statistically significant correlations between tissue metal concentrations and sediment metal concentrations were found for a subset of metals. Metals were generally found in higher concentrations in the larger snapping turtles than in painted turtles. In addition, non-lethal samples of shell and claw were found to be possible alternatives to lethal liver and muscle samples for some metals. Human consumption of snapping turtles presents potential health risks if turtles are harvested from contaminated areas. Overall, our results suggest that turtles could be a valuable component of contaminant monitoring programs for wetland ecosystems.

  1. 40 CFR 81.67 - Lake Michigan Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Regions § 81.67 Lake Michigan Intrastate Air Quality Control Region. The Menominee-Escanaba (Michigan)-Marinette (Wisconsin) Interstate Air Quality Control Region has been renamed the Lake Michigan Intrastate Air Quality Control Region (Wisconsin) and revised to consist of the territorial area...

  2. Seasonal stability of Cladophora-associated Salmonella in Lake Michigan watersheds

    Science.gov (United States)

    Byappanahalli, M.N.; Sawdey, R.; Ishii, S.; Shively, D.A.; Ferguson, J.A.; Whitman, R.L.; Sadowsky, M.J.

    2009-01-01

    The bacterial pathogens Shigella, Salmonella, Campylobacter, and shiga toxin-producing E. coli (STEC) were recently found to be associated with Cladophora growing in southern Lake Michigan. Preliminary results indicated that the Salmonella strains associated with Cladophora were genetically identical to each other. However, because of the small sample size (n = 37 isolates) and a lack of information on spatial-temporal relationships, the nature of the association between Cladophora and Salmonella remained speculative. In this study, we investigated the population structure and genetic relatedness of a large number of Cladophora-borne Salmonella isolates from Lake Michigan (n = 133), as well as those isolated from stream and lake water (n = 31), aquatic plants (n = 8), and beach sands and sediments (n = 8) from adjacent watersheds. Salmonella isolates were collected during 2005-2007 between May and August from Lake Michigan beachsheds in Wisconsin, Illinois, and Indiana. The genetic relatedness of Salmonella isolates was examined by using the horizontal, fluorophore-enhanced rep-PCR (HFERP) DNA fingerprinting technique. While the Salmonella isolates associated with Cladophora exhibited a high degree of genetic relatedness (???92% similarity), the isolates were not all genetically identical. Spatial and temporal relationships were evident in the populations examined, with tight clustering of the isolates both by year and location. These findings suggest that the relationship between Salmonella and Cladophora is likely casual and is related to input sources (e.g. wastewater, runoff, birds) and the predominant Salmonella genotype surviving in the environment during a given season. Our studies indicate that Cladophora is likely an important reservoir for Salmonella and other enteric bacterial pathogens in Lake Michigan beachsheds, which in turn may influence nearshore water quality. ?? 2008 Elsevier Ltd.

  3. Seasonal stability of Cladophora-associated Salmonella in Lake Michigan watersheds.

    Science.gov (United States)

    Byappanahalli, Muruleedhara N; Sawdey, Richard; Ishii, Satoshi; Shively, Dawn A; Ferguson, John A; Whitman, Richard L; Sadowsky, Michael J

    2009-02-01

    The bacterial pathogens Shigella, Salmonella, Campylobacter, and shiga toxin-producing E. coli (STEC) were recently found to be associated with Cladophora growing in southern Lake Michigan. Preliminary results indicated that the Salmonella strains associated with Cladophora were genetically identical to each other. However, because of the small sample size (n=37 isolates) and a lack of information on spatial-temporal relationships, the nature of the association between Cladophora and Salmonella remained speculative. In this study, we investigated the population structure and genetic relatedness of a large number of Cladophora-borne Salmonella isolates from Lake Michigan (n=133), as well as those isolated from stream and lake water (n=31), aquatic plants (n=8), and beach sands and sediments (n=8) from adjacent watersheds. Salmonella isolates were collected during 2005-2007 between May and August from Lake Michigan beachsheds in Wisconsin, Illinois, and Indiana. The genetic relatedness of Salmonella isolates was examined by using the horizontal, fluorophore-enhanced rep-PCR (HFERP) DNA fingerprinting technique. While the Salmonella isolates associated with Cladophora exhibited a high degree of genetic relatedness (>or=92% similarity), the isolates were not all genetically identical. Spatial and temporal relationships were evident in the populations examined, with tight clustering of the isolates both by year and location. These findings suggest that the relationship between Salmonella and Cladophora is likely casual and is related to input sources (e.g. wastewater, runoff, birds) and the predominant Salmonella genotype surviving in the environment during a given season. Our studies indicate that Cladophora is likely an important reservoir for Salmonella and other enteric bacterial pathogens in Lake Michigan beachsheds, which in turn may influence nearshore water quality.

  4. Nearshore Placement Techniques in Southern Lake Michigan

    Science.gov (United States)

    2018-03-01

    of water in small discrete mounds to prevent the sediment from obstructing the hanging gates of the scow from closing. The sediment will be...mobilized more frequently, and more energy will be dissipated if the dredged sediment is placed in shallower depths in the shape of an elongated bar or...Acting Chief, CEERD-HN-C, and Mr. Charles E. Wiggins was Acting Chief, CEERD-HN. Ms. Linda S. Lillycrop, CEERD-HN-C, was the USACE National RSM

  5. Impact of cooling systems on Lake Michigan fishes

    International Nuclear Information System (INIS)

    Spigarelli, S.A.; Romberg, G.P.

    1976-01-01

    A comparison of data on fish mortalities due to impingement at thermal power plant water intakes on Lake Michigan with available estimates of standing crop biomass, commercial and sport fishery catches, and estimated predation mortality is presented. The striking features of these data are the proportions of total mortality due to predation and the lack of accurate basic population statistics such as standing crop biomass and natural mortality for important forage and human food fishes in Lake Michigan. Although this preliminary assessment would indicate that power plant and total impingement losses constitute an insignificant fraction of total forage biomass, the potentially unstable forage-predator ratios and the apparent high degree of annual fluctuations (year-classes) in alewife, smelt, and perch indicate the need for a more detailed assessment of cooling-system related impact on selected populations

  6. Establishment of two invasive crustaceans (Copepoda: Harpacticoida) on the nearshore sands of Lake Michigan

    Science.gov (United States)

    Horvath, Thomas G.; Whitman, Richard L.; Last, Laurel L.

    2001-01-01

    Benthic copepods (Copepoda: Harpacticoida) in the nearshore sediments of southern Lake Michigan appear to be dominated by two new invasive species. We report the first occurrence in North America of Schizopera borutzkyi Montschenko, a native to the Danube River delta, and Heteropsyllus nr. nunni, likely a new species that is morphologically similar to the marine species Heteropsyllus nunni and represents the first occurrence of this genus in freshwater. Schizopera borutzkyi is a euryhaline species occurring in shallow sands in its native habitat and in deeper sands (6-15 m) in southern Lake Michigan. Based on the absence of these species from previous studies, we suggest that they are recent introductions. Heteropsyllus nr. nunni dominated (55-100%) the harpacticoid abundance to depths of 9 m, but S. borutzkyi comprised 75% of the harpacticoid abundance at 15 m. Native harpacticoids were always greatly outnumbered by invasive harpacticoids in our samples, which suggests that the natives are being replaced rapidly or that the invasive species are finding unused resources. The ecological implications of these introductions are not known, but these invasions may represent continued 'invasional meltdown' in Lake Michigan.

  7. 239 240Pu in Lake Michigan: 1971 to 1978

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Nelson, D.M.; Orlandini, K.A.; Kucera, E.T.

    1978-01-01

    The plutonium concentration data presented previously have consisted primarily of results from studies of short-term variations, i.e., the annual plutonium cycle conducted at Lake Michigan station ANL-5, 12 km SW of Grand Haven, Michigan. In this report, mean annual concentrations of total plutonium in unfiltered water from far off-shore (> 30 km) stations for the period 1971 through 1977, and from station ANL-5 (1975 through 1978) are summarized to establish the long-term trend in plutonium concentration in Lake Michigan. The results presented show that the mean annual concentration in the water column is similar at ANL-5 and at offshore stations and has decreased at the rate of only 6% per year during the period 1972 through 1978. The nearly constant concentration indicates that steady-state equilibria exist between plutonium inputs to the lake and the loss of plutonium from the water column. Observations suggest the existence of an active redox cycle for Pu in Lake Michigan. In this cycle, Pu IV atoms in solution are continually taken up by particulate materials but may be oxidized within microzones of the particles such as freshly deposited manganese coatings and also in solution by agents such as dissolved oxygen. In turn, the concentration of Pu VI in solution may be limited by reaction with reducing constituents of the coloidal-sized fraction (or decomposer organisms such as bacteria or fungi, which might have been present after filtration) and with planktonic organisms in the environment to produce Pu IV and thus maintain the cycle

  8. Lake Michigan Wind Assessment Analysis, 2012 and 2013

    Directory of Open Access Journals (Sweden)

    Charles R Standridge

    2017-03-01

    Full Text Available A study was conducted to address the wind energy potential over Lake Michigan to support a commercial wind farm.  Lake Michigan is an inland sea in the upper mid-western United States.  A laser wind sensor mounted on a floating platform was located at the mid-lake plateau in 2012 and about 10.5 kilometers from the eastern shoreline near Muskegon Michigan in 2013.  Range gate heights for the laser wind sensor were centered at 75, 90, 105, 125, 150, and 175 meters.  Wind speed and direction were measured once each second and aggregated into 10 minute averages.  The two sample t-test and the paired-t method were used to perform the analysis.  Average wind speed stopped increasing between 105 m and 150 m depending on location.  Thus, the collected data is inconsistent with the idea that average wind speed increases with height. This result implies that measuring wind speed at wind turbine hub height is essential as opposed to using the wind energy power law to project the wind speed from lower heights.  Average speed at the mid-lake plateau is no more that 10% greater than at the location near Muskegon.  Thus, it may be possible to harvest much of the available wind energy at a lower height and closer to the shoreline than previously thought.  At both locations, the predominate wind direction is from the south-southwest.  The ability of the laser wind sensor to measure wind speed appears to be affected by a lack of particulate matter at greater heights.   Keywords: wind assessment, Lake Michigan, LIDAR wind sensor, statistical analysis. Article History: Received June 15th 2016; Received in revised form January 16th 2017; Accepted February 2nd 2017 Available online How to Cite This Article: Standridge, C., Zeitler, D., Clark, A., Spoelma, T., Nordman, E., Boezaart, T.A., Edmonson, J.,  Howe, G., Meadows, G., Cotel, A. and Marsik, F. (2017 Lake Michigan Wind Assessment Analysis, 2012 and 2013. Int. Journal of Renewable Energy Development

  9. Lake Erie and Lake Michigan zebra mussel settlement monitoring and implications for chlorination treatment

    International Nuclear Information System (INIS)

    Demoss, D.; Mendelsberg, J.I.

    1992-01-01

    This paper reports on the 1991 zebra mussel veliger settlement monitoring program undertaken to record and evaluate zebra mussel veliger settlement in Lake Erie and Lake Michigan. Studies by Dr. Gerald Mackie of Canada in 1990 indicated veliger settlement may be occurring primarily during short time periods every season corresponding with warmer water temperatures. Veliger settlement monitoring was performed using a plexiglass sampler apparatus. The samplers were simple in design and consisted of a 20-inch-square plexiglass base panel with thirty-six 1 inch x 3 inch clear plexiglass microscope slides attached. The results of the monitoring program indicate the existence of preferential settlement periods for veligers correlating with sustained lake water temperatures above 70 degrees F. Veliger settlement concentrations in the south basin of Lake Michigan appear to be similar to those in western Lake Erie

  10. Environmental status of the Lake Michigan region. Volume 16. Amphibians and reptiles of the Lake Michigan drainage basin

    Energy Technology Data Exchange (ETDEWEB)

    Pentecost, E.D.; Vogt, R.C.

    1976-07-01

    The focus of this report is on regional distribution of the herpetofauna of the Lake Michigan Drainage Basin. The introduction includes a brief discussion of plant communities and their associated herpetofauna, and the importance of hibernacula and migration routes. Some aspects of the status, distribution, habitat, and life history of the amphibians and reptiles of the Basin are described in an annotated checklist. Special attention is given to uncommon and endangered species. Species range is shown on distribution maps.

  11. Environmental status of the Lake Michigan region. Volume 16. Amphibians and reptiles of the Lake Michigan drainage basin

    International Nuclear Information System (INIS)

    Pentecost, E.D.; Vogt, R.C.

    1976-07-01

    The focus of this report is on regional distribution of the herpetofauna of the Lake Michigan Drainage Basin. The introduction includes a brief discussion of plant communities and their associated herpetofauna, and the importance of hibernacula and migration routes. Some aspects of the status, distribution, habitat, and life history of the amphibians and reptiles of the Basin are described in an annotated checklist. Special attention is given to uncommon and endangered species. Species range is shown on distribution maps

  12. 75 FR 26094 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Science.gov (United States)

    2010-05-11

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... establishing a temporary safety zone from Brandon Road Lock and Dam to Lake Michigan. This temporary safety...

  13. National Water-Quality Assessment Program, western Lake Michigan drainages: Summaries of liaison committee meeting, Green Bay, Wisconsin, March 28-29, 1995

    Science.gov (United States)

    Peters, Charles A.

    1995-01-01

    The Western Lake Michigan Drainages (WMIC) study unit, under investigation since 1991, drains 20,000 square miles (mi2) in eastern Wisconsin and Upper Michigan (fig. 1). The major water-quality issues in the WMIC study unit are: (1) nonpoint-source contamination of surface and ground water by agricultural chemicals, (2) contamination in bottom sediments of rivers and harbors by toxic substances, including polychlorinated biphenyls (PCB's), other synthetic organic compounds, and trace elements, (3) nutrient enrichment of rivers and lakes resulting from nonpoint- and point-source discharges, and (4) acidification and mercury contamination of lakes in poorly buffered watersheds in the northwestern part of the study unit.

  14. Estimation of alewife biomass in Lake Michigan, 1967-1978

    Science.gov (United States)

    Hatch, Richard W.; Haack, Paul M.; Brown, Edward H.

    1981-01-01

    The buildup of salmonid populations in Lake Michigan through annual stockings of hatchery-reared fish may become limited by the quantity of forage fish, mainly alewives Alosa pseudoharengus, available for food. As a part of a continuing examination of salmonid predator-prey relations in Lake Michigan, we traced changes in alewife biomass estimated from bottom-trawl surveys conducted in late October and early November 1967–1978. Weight of adult alewives trawled per 0.5 hectare of bottom (10-minute drag) at 16 depths along eight transects between 1973 and 1977 formed a skewed distribution: 72 of 464 drags caught no alewives; 89 drags caught less than 1 kg; and 2 drags caught more than 100 kg (maximum 159 kg). Analysis of variance in normalized catch per tow indicated highly significant differences between the main effects of years and depths, and highly significant differences in the interactions of years and transects, years and depths, and transects and depths. Five geographic and depth strata, formed by combining parts of transects wherein mean catch rate did not differ significantly, were the basis for calculating annual estimates of adult alewife biomass (with 90% confidence intervals). Estimated biomass of alewives (±90% confidence limits) in Lake Michigan proper (Green Bay and Grand Traverse Bay excluded) rose gradually from 46,000 (±9,000) t in 1967 to 114,000 (±17,000) t in 1973, declined to 45,000 (±8,000) t in 1977, and rose to 77,000 (±19,000) t in 1978.

  15. Comparison between polluted and clean air masses over Lake Michigan

    International Nuclear Information System (INIS)

    Alkezweeny, A.J.; Laulainen, N.S.

    1981-01-01

    Clean and polluted air masses, advected over Lake Michigan, were studied using instrumental aircraft during the summers of 1976 and 1978. The results show that regardless of the degree of pollution, the particle size distribution is bimodal. The concentrations of sulfate, nitrate and trace metals in a clean air mass are more than an order of magnitude lower than those in polluted air masses. Furthermore, these concentrations are comparable with those measured in remote areas of the world. In clean air the ratio of the total light scattering to Rayleigh scattering is very close to one, indicating very low concentrations of particulates in the optically active size classes

  16. 76 FR 48751 - Security Zones; Captain of the Port Lake Michigan Zone

    Science.gov (United States)

    2011-08-09

    ... Jardine Water Filtration Plant security zone would encompass all U.S. navigable waters of Lake Michigan... areas near shore to Chicago's water filtration plants; the security zones have been designed to allow.... 165.910 Security Zones; Captain of the Port Lake Michigan. (a) * * * (1) Jardine Water Filtration...

  17. 75 FR 32664 - Safety Zone; Milwaukee Air and Water Show, Lake Michigan, Milwaukee, WI

    Science.gov (United States)

    2010-06-09

    .... ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a safety zone on Lake Michigan... of Lake Michigan due to a large-scale air show and a fireworks display. This temporary safety zone is... air show and fireworks display. DATES: This regulation is effective from 12:01 a.m. on June 10, 2010...

  18. 76 FR 63202 - Security Zones; Captain of the Port Lake Michigan Zone

    Science.gov (United States)

    2011-10-12

    ..., SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays... Filtration Plant security zone will encompass all U.S. navigable waters of Lake Michigan within an arc of a..., Illinois. It encompasses all U.S. navigable waters of Lake Michigan within the arc of a circle with a 100...

  19. 78 FR 17099 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Science.gov (United States)

    2013-03-20

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... Guard will enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including...

  20. 78 FR 49684 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2013-08-15

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

  1. 77 FR 20295 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Science.gov (United States)

    2012-04-04

    ... Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  2. 78 FR 65874 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2013-11-04

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... Guard will enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including...

  3. 75 FR 73966 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2010-11-30

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  4. 76 FR 23524 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2011-04-27

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago... safety zone from Brandon Road Lock and Dam to Lake Michigan. This proposed safety zone will cover 77.... This TIR established a 77 mile long safety zone from Brandon Road Lock to Lake Michigan in Chicago, IL...

  5. 78 FR 4071 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2013-01-18

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... Coast Guard will enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan...

  6. 78 FR 36091 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2013-06-17

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

  7. 77 FR 35854 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2012-06-15

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  8. 75 FR 64673 - Safety Zone, Brandon Road Lock and, Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2010-10-20

    ... Zone, Brandon Road Lock and, Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and... Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Ship and...: The Coast Guard will enforce Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des...

  9. 78 FR 40635 - Safety Zone; Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2013-07-08

    ... Zone; Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... Coast Guard will enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan...

  10. 78 FR 36092 - Safety Zone; Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2013-06-17

    ... Zone; Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... Coast Guard will enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan...

  11. 77 FR 65478 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Science.gov (United States)

    2012-10-29

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River...

  12. 76 FR 63199 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2011-10-12

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal...

  13. 76 FR 2829 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2011-01-18

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  14. 75 FR 64147 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2010-10-19

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Ship and Sanitary Canal... . SUPPLEMENTARY INFORMATION: The Coast Guard will enforce Safety Zone, Brandon Road Lock and Dam to Lake Michigan...

  15. 75 FR 52462 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2010-08-26

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  16. 77 FR 60044 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2012-10-02

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River...

  17. Response of the St. Joseph River to lake level changes during the last 12,000 years in the Lake Michigan basin

    Science.gov (United States)

    Kincare, K.A.

    2007-01-01

    The water level of the Lake Michigan basin is currently 177 m above sea level. Around 9,800 14C years B.P., the lake level in the Lake Michigan basin had dropped to its lowest level in prehistory, about 70 m above sea level. This low level (Lake Chippewa) had profound effects on the rivers flowing directly into the basin. Recent studies of the St. Joseph River indicate that the extreme low lake level rejuvenated the river, causing massive incision of up to 43 m in a valley no more than 1.6 km wide. The incision is seen 25 km upstream of the present shoreline. As lake level rose from the Chippewa low, the St. Joseph River lost competence and its estuary migrated back upstream. Floodplain and channel sediments partially refilled the recently excavated valley leaving a distinctly non-classical morphology of steep sides with a broad, flat bottom. The valley walls of the lower St. Joseph River are 12-18 m tall and borings reveal up to 30 m of infill sediment below the modern floodplain. About 3 ?? 108 m3 of sediment was removed from the St. Joseph River valley during the Chippewa phase lowstand, a massive volume, some of which likely resides in a lowstand delta approximately 30 km off-shore in Lake Michigan. The active floodplain below Niles, Michigan, is inset into an upper terrace and delta graded to the Calumet level (189 m) of Lake Chicago. In the lower portion of the terrace stratigraphy a 1.5-2.0 m thick section of clast-supported gravel marks the entry of the main St. Joseph River drainage above South Bend, Indiana, into the Lake Michigan basin. This gravel layer represents the consolidation of drainage that probably occurred during final melting out of ice-marginal kettle chains allowing stream piracy to proceed between Niles and South Bend. It is unlikely that the St. Joseph River is palimpsest upon a bedrock valley. The landform it cuts across is a glaciofluvial-deltaic feature rather than a classic unsorted moraine that would drape over pre-glacial topography

  18. Mixed stock analysis of Lake Michigan's Lake Whitefish Coregonus clupeaformis commercial fishery

    Science.gov (United States)

    Andvik, Ryan; Sloss, Brian L.; VanDeHey, Justin A.; Claramunt, Randall M.; Hansen, Scott P.; Isermann, Daniel A.

    2016-01-01

    Lake whitefish (Coregonus clupeaformis) support the primary commercial fishery in Lake Michigan. Discrete genetic stocks of lake whitefish have been identified and tagging data suggest stocks are mixed throughout much of the year. Our objectives were to determine if (1) differential stock harvest occurs in the commercial catch, (2) spatial differences in genetic composition of harvested fish were present, and (3) seasonal differences were present in the harvest by commercial fisheries that operate in management zones WI-2 and WFM-01 (Green Bay, Lake Michigan). Mixed stock analysis was conducted on 17 commercial harvest samples (n = 78–145/sample) collected from various ports lake-wide during 2009–2010. Results showed significant mixing with variability in stock composition across most samples. Samples consisted of two to four genetic stocks each accounting for ≥ 10% the catch. In 10 of 17 samples, the stock contributing the largest proportion made up differences existed in the proportional stock contribution at a single capture location. Samples from Wisconsin's primary commercial fishing management zone (WI-2) were composed predominately of fish from the Big Bay de Noc (Michigan) stock as opposed to the geographically proximate, North–Moonlight Bay (Wisconsin) stock. These findings have implications for management and allocation of fish to various quotas. Specifically, geographic location of harvest, the current means of allocating harvest quotas, is not the best predictor of genetic stock harvest.

  19. Life history of lake herring of Green Bay, Lake Michigan

    Science.gov (United States)

    Smith, Stanford H.

    1956-01-01

    Although the lake herring has been an important contributor to the commercial fish production of Green Bay, little has been known about it. This study is based on field observations and data from about 6,500 lake herring collected over the period 1948 to 1952. Relatively nonselective commercial pound nets were a primary source of material for the study of age and growth. Commercial and experimental gill nets were used to obtain data on gear selectivity and vertical distribution. Scales were employed to investigate age and growth. Age group IV normally dominated commercial catches during the first half of the calendar year and age group III the last half. At these ages the fish averaged about 10.5 inches in length. The season's growth started in May, was most rapid in July, and terminated near the end of October. The sexes grew at the same rate. Selectivity of fishing gear was found to influence the estimation of growth. Geographical and annual differences in growth are shown. Factors that might contribute to discrepancies in calculated growth are evaluated. Possible real and apparent causes of growth compensation are given. The relation between length and weight is shown to vary with sex, season, year, and method of capture. Females were relatively more plentiful in commercial catches in February than in May through December. The percentage of females decreased with increase in age in pound-net catches but increased with age in gill-net samples. Within a year class the percentage of females decreased with increase in age. Most Green Bay lake herring mature during their second or third year of life. They are pelagic spawners with most intensive spawning over shallow areas. Spawning takes place between mid-November and mid-December, and eggs hatch in April and May. Lake herring ovaries contained from 3,500 to 11,200 eggs (averaged 6,375). Progress of spawning by age, sex, and length is given. Lake herring were distributed at all depths in Green Bay in early May, were

  20. Radiological survey results at 4400 Piehl Road, Ottawa Lake, Michigan

    International Nuclear Information System (INIS)

    Foley, R.D.; Johnson, C.A.

    1993-04-01

    At the request of the US Department of Energy (DOE), a team from Oak Ridge National Laboratory conducted a radiological survey at 4400 Piehl Road in Ottawa Lake, Michigan. The survey was performed in September, 1992. The purpose of the survey was to determine if materials containing uranium from work performed under government contract at the former Baker Brothers facility in Toledo, Ohio had been transported off-site to this neighboring area. The radiological survey included surface gamma scans indoors and outdoors, alpha and beta scans inside the house and attached garage, beta-gamma scans of the hard surfaces outside, and the collection of soil, water, and dust samples for radionuclide analyses. Results of the survey demonstrated that the majority of the measurements on the property were within DOE guidelines. However, the presence of isolated spots of uranium contamination were found in two areas where materials were allegedly transported to the property from the former Baker Brothers site. Uranium uptake by persons on the property by ingestion is fairly unlikely, but inhalation is a possibility. Based on these findings, it is recommended that the residential property at 4400 Piehl Road in Ottawa Lake, Michigan be considered for inclusion under FUSRAP

  1. The food of the lake trout (Cristivomer namaycush namaycush) and of the lawyer (Lota maculosa) of Lake Michigan

    Science.gov (United States)

    Van Oosten, John; Deason, Hilary J.

    1938-01-01

    This paper reports on a qualitative and quantitative analysis of the contents of 4,979 lake trout stomachs (593 examined in 1930 and 1,253 collected in 1931 from southern Lake Michigan, 1,446 from northern Lake Michigan and 1,687 from Green Bay in 1932), and of a total of 1,528 lawyer stomachs (172 examined in 1930 and 734 collected in 1931 from southern Lake Michigan, 612 from northern Lake Michigan and 10 from Green Bay in 1932). The food of the trout consisted of 98 per cent by volume of fish of which Cottidae and Coregonidae were the principal constituents. Cottidae were dominant in southern Lake Michigan (72 per cent by volume), Coregonidae in northern Lake Michigan (51 per cent) but the lake shiner, Notropis atherinides, was most important in Green Bay in the spring of the year (64 per cent). The lawyer food consisted of 74 per cent by volume of fish and 26 per cent invertebrates. Dominant items were Cottidae (76 per cent by volume) in southern Lake Michigan, Coregonidae (51 per cent) and Pontoporeia (37 per cent) in northern Lake Michigan, and Percopsis (34 per cent) and Mysis (26 per cent) in Green Bay. Data are also presented on the frequency of occurrence (number of stomachs) of the food items and its variation with the sizes of the trout and lawyers, depths of water, seasons, and localities; on the number of individual fish of each species destroyed by the trout and lawyers; and on the calculated volume of the food fishes preceding digestion. The lake trout and lawyer are competitors for the same food, are both predators of the commercially important Coregonidae, and the lawyer through its consumption of invertebrates is a food competitor of the Coregonidae.

  2. Results of photochemical modeling sensitivity analyses in the Lake Michigan region: Current status of Lake Michigan Ozone Control Program (LMOP) modeling

    Energy Technology Data Exchange (ETDEWEB)

    Dolwick, P.D. [Lake Michigan Air Directors Consortium, Des Plaines, IL (United States); Kaleel, R.J. [Illinois Environmental Protection Agency, Springfield, IL (United States); Majewski, M.A. [Wisconsin Dept. of Natural Resources, Madison, WI (United States)

    1994-12-31

    The four states that border Lake Michigan are cooperatively applying a state-of-the-art nested photochemical grid model to assess the effects of potential emission control strategies on reducing elevated tropospheric ozone concentrations in the region to levels below the national ambient air quality standard. In order to provide an extensive database to support the application of the photochemical model, a substantial data collection effort known as the Lake Michigan Ozone Study (LMOS) was completed during the summer of 1991. The Lake Michigan Ozone Control Program (LMOP) was established by the States of Illinois, Wisconsin, Michigan, and Indiana to carry out the application of the modeling system developed from the LMOS, in terms of developing the attainment demonstrations required from this area by the Clean Air Act Amendments of 1990.

  3. Deglaciation, lake levels, and meltwater discharge in the Lake Michigan basin

    Science.gov (United States)

    Colman, Steven M.; Clark, J.A.; Clayton, L.; Hansel, A.K.; Larsen, C.E.

    1994-01-01

    The deglacial history of the Lake Michigan basin, including discharge and routing of meltwater, is complex because of the interaction among (1) glacial retreats and re-advances in the basin (2) the timing of occupation and the isostatic adjustment of lake outlets and (3) the depositional and erosional processes that left evidence of past lake levels. In the southern part of the basin, a restricted area little affected by differential isostasy, new studies of onshore and offshore areas allow refinement of a lake-level history that has evolved over 100 years. Important new data include the recognition of two periods of influx of meltwater from Lake Agassiz into the basin and details of the highstands gleaned from sedimentological evidence. Major disagreements still persist concerning the exact timing and lake-level changes associated with the Algonquin phase, approximately 11,000 BP. A wide variety of independent data suggests that the Lake Michigan Lobe was thin, unstable, and subject to rapid advances and retreats. Consequently, lake-level changes were commonly abrupt and stable shorelines were short-lived. The long-held beliefs that the southern part of the basin was stable and separated from deformed northern areas by a hinge-line discontinuity are becoming difficult to maintain. Numerical modeling of the ice-earth system and empirical modeling of shoreline deformation are both consistent with observed shoreline tilting in the north and with the amount and pattern of modern deformation shown by lake-level gauges. New studies of subaerial lacustrine features suggest the presence of deformed shorelines higher than those originally ascribed to the supposed horizontal Glenwood level. Finally, the Lake Michigan region as a whole appears to behave in a similar manner to other areas, both local (other Great Lakes) and regional (U.S. east coast), that have experienced major isostatic changes. Detailed sedimentological and dating studies of field sites and additional

  4. Excretion is Faster Than Diagenesis for Nutrient Recycling in Lake Michigan Benthos

    Science.gov (United States)

    Aguilar, C.; Cuhel, R. L.

    2013-12-01

    Regeneration of phytoplankton growth nutrients including ammonium (NH4+) and phosphate (HPO4=) occurs in aquatic systems worldwide through biogeochemical processes of diagenesis. Organic matter falling to the bottom accumulates in sediments, and bacterial decomposition removes oxygen from the sub-surface. Anaerobic metabolism is energetically inefficient, and bacteria a few cm below the surface respire or ferment organic matter into carbon dioxide or organic acids, excreting nitrogen (NH4+) or phosphorus inorganic 'waste'. Subsurface production of bacterial metabolic products often leads to sharp gradients in porewater concentrations of NH4+ and HPO4=, which drive diffusive flux out of the sediments into overlying water. Aquatic systems with totally aerobic water overlying anoxic sediment (e.g., Lake Michigan) have muted efflux of certain inorganic nutrients arising from organic matter decomposition. For example, NH4+ is oxidized to nitrate in the upper few mm of surficial sediments by nitrifying bacteria. Strong subsurface porewater gradients, especially of redox- or geochemically-reactive compounds, often decline to low values well below the sediment-water interface, indicating transformation by sediment bacterial populations, or by purely geochemical processes such as calcium hydroxyphosphate (apatite) precipitation. For these, little flux to the water column occurs. In Lake Michigan, neither NH4+ nor HPO4= escapes substantially from the biogeochemical barriers between their diagenetic sources and overlying waters, either before or after ecosystem alteration by invasive quagga mussels (QM). Silicate and total CO2 evade unimpeded in the same cores. The organic matter deposited from the water column is also the nutrition of benthic bivalve filter feeders such as QM in Lake Michigan, or the Asian Clam in San Francisco Bay. In animal metabolism for energy production, only the carbon component is oxidized through respiration, with NH4+ (from protein) and HPO4= (from

  5. Observations of cocooned Hydrobaenus (Diptera: Chironomidae) larvae in Lake Michigan

    Science.gov (United States)

    Tucker, Taaja R.; Hudson, Patrick L.; Riley, Stephen

    2016-01-01

    Larvae of the family Chironomidae have developed a variety of ways to tolerate environmental stress, including the formation of cocoons, which allows larvae to avoid unfavorable temperature conditions, drought, or competition with other chironomids. Summer cocoon formation by younger instars of the genus Hydrobaenus Fries allows persistence through increased temperatures and/or intermittent dry periods in arid regions or temporary habitats, but this behavior was not observed in the Great Lakes until the current study. Cocoon-aestivating Hydrobaenus sp. larvae were found in benthic grab samples collected in 2010–2013 near Sleeping Bear Dunes National Lakeshore in northern Lake Michigan with densities up to 7329/m2. The aestivating species was identified as Hydrobaenus johannseni (Sublette, 1967), and the associated chironomid community was typical for an oligotrophic nearshore system. Hydrobaenus cocoon formation in the Great Lakes was likely previously unnoticed due to the discrepancies between the genus' life history and typical benthos sampling procedures which has consequences for describing chironomid communities where Hydrobaenus is present.

  6. Introduction and spread of the threespine stickleback (Gasterosteus aculeatus) in Lakes Huron and Michigan

    Science.gov (United States)

    Stedman, Ralph M.; Bowen, Charles A.

    1985-01-01

    The threespine stickleback (Gasterosteus aculeatus) was not known to occur in the Great Lakes above Niagara Falls until 1980, when it was collected in South Bay, Manitoulin Island, in the Lake Huron basin. By 1984 this species had been found in tributaries of Lakes Huron and Michigan, and in the open waters of both lakes. All specimens identified were the completely plated morph that is most prevalent in fresh water along the east coast of North America. The status of this species in Lakes Huron and Michigan appears to be “Possibly Established.” If threespine stickleback increase in abundance they may eventually provide additional forage for large salmonids.

  7. Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.

    Science.gov (United States)

    Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.; Brown, S.B.

    2009-01-01

    We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos.

  8. A previously unrecognized path of early Holocene base flow and elevated discharge from Lake Minong to Lake Chippewa across eastern Upper Michigan

    Science.gov (United States)

    Loope, Walter L.; Jol, Harry M.; Fisher, Timothy G.; Blewett, William L.; Loope, Henry M.; Legg, Robert J.

    2014-01-01

    It has long been hypothesized that flux of fresh meltwater from glacial Lake Minong in North America's Superior Basin to the North Atlantic Ocean triggered rapid climatic shifts during the early Holocene. The spatial context of recent support for this idea demands a reevaluation of the exit point of meltwater from the Superior Basin. We used ground penetrating radar (GPR), foundation borings from six highway bridges, a GIS model of surface topography, geologic maps, U.S. Department of Agriculture–Natural Resources Conservation Service soils maps, and well logs to investigate the possible linkage of Lake Minong with Lake Chippewa in the Lake Michigan Basin across eastern Upper Michigan. GPR suggests that a connecting channel lies buried beneath the present interlake divide at Danaher. A single optical age hints that the channel aggraded to 225 m as elevated receipt of Lake Agassiz meltwater in the Superior Basin began to wane GIS model of Minong's shoreline are consistent with another transgression of Minong after ca. 9.5 ka. At the peak of the latter transgression, the southeastern rim of the Superior Basin (Nadoway Drift Barrier) failed, ending Lake Minong. Upon Minong's final drop, aggradational sediments were deposited at Danaher, infilling the prior breach.

  9. 75 FR 70595 - Limited Service Domestic Voyage Load Lines for River Barges on Lake Michigan

    Science.gov (United States)

    2010-11-18

    ... similar request for an eastern Lake Michigan route between Chicago, IL, and Muskegon, MI. The motivation... tow loaded with wheat departed from Milwaukee and traveled southbound for Chicago. Although the 48...

  10. Notable decomposition products of senescing Lake Michigan Cladophora glomerata

    Science.gov (United States)

    Peller, Julie R.; Byappanahalli, Muruleedhara N.; Shively, Dawn A.; Sadowsky, Michael J.; Chun, Chan Lan; Whitman, Richard L.

    2013-01-01

    Massive accumulations of Cladophora, a ubiquitous, filamentous green alga, have been increasingly reported along Great Lakes shorelines, negatively affecting beach aesthetics, recreational activities, public health and beachfront property values. Previously, the decomposition byproducts of decaying algae have not been thoroughly examined. To better understand the negative consequences and potential merit of the stranded Cladophora, a three month mesocosm study of the dynamic chemical environment of the alga was conducted using fresh samples collected from southern Lake Michigan beaches. Typical fermentation products, such as organic acids, sulfide compounds, and alcohols were detected in the oxygen–deprived algae. Short chain carboxylic acids peaked on day seven, in correspondence with the lowest pH value. Most low molecular mass carbon compounds were eventually consumed, but 4-methylphenol, indole, and 3-methylindole were detected throughout the incubation period. Natural oils were detected in fresh and decomposing algae, indicating the stable nature of these compounds. The mesocosm experiment was validated by directly sampling the fluid within decomposing Cladophora mats in the field; many of the same compounds were found. This study suggests that the problematic Cladophora accumulations may be harvested for useful byproducts, thereby reducing the odiferous and potentially harmful mats stranded along the shorelines.

  11. Cisco (Coregonus artedii) mortalities in a southern Michigan lake, July 1968

    Science.gov (United States)

    Colby, Peter J.; Brooke, Larry T.

    1969-01-01

    Cisco die-offs are common in the summer in certain lakes of northern Indiana and southern Michigan, along the southern boundary of the national distribution of coregonine fishes. Although numerous cisco die-offs have been reported, few, if any, have been accompanied by environmental information at the time of the die-off. On 31 July and 1 August 1968, we investigated a cisco die-off on Halfmoon Lake, on the border of Washtenaw and Livingston Counties, Michigan.

  12. Determination of arsenic in some Lake Michigan fish using neutron activation analysis

    International Nuclear Information System (INIS)

    Nicholson, L.W.; Rengan, K.

    1979-01-01

    The level of arsenic in six different species of fish collected from Lake Michigan near Saugatuck, Michigan has been measured using radiochemical neutron activation analysis. The arsenic concentration was found to vary from 0.05 μg/g (wet weight) for yellow perch fillet to 1.4 μg/g (wet weight) for eviscerated bloater chubs. A significant correlation was observed between arsenic concentrations and number of years in the lake for lake trout; correlations were also observed between arsenic concentrations and length of lake trout and smelt. No such correlations were found for alewife or yellow perch. (author)

  13. 76 FR 78161 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2011-12-16

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... INFORMATION: The Coast Guard will enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake...

  14. 76 FR 65609 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2011-10-24

    ... Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship Canal... Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal, Chicago... INFORMATION: The Coast Guard will enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake...

  15. Anthropopression markers in lake bottom sediments

    Science.gov (United States)

    Nadolna, Anna; Nowicka, Barbara

    2014-05-01

    Lakes are vulnerable to various types of anthropogenic disturbances. Responses of lake ecosystems to environmental stressors are varied and depend not only on the type of a factor but also on the lake natural resistance to degradation. Within the EULAKES project an evaluation of anthropogenic stress extent in a flow-through, postglacial, ribbon lake (Lake Charzykowskie) was carried out. It was assumed, that this impact manifests unevenly, depending on a type and degree of the pressure on the shore zones, water quality of tributaries, lake basin shape and dynamics of a water movement. It was stated, that anthropogenic markers are substances accumulated in bottom sediments as a result of allochthonous substances inflow from the catchment and atmosphere. Along the selected transects 105 samples from the top layer of sediments (about 20 cm) was collected representing the contemporary accumulation (about 15 years). The content of selected chemical elements and compounds was examined, including nutrients (TN and TP), heavy metals (arsenic, cadmium, lead, chromium, nickel, copper, zinc, mercury, iron, and manganese) and pesticides (DDT, DDD, DDE, DMDT , γ-HCH). The research was conducted in the deepest points of each lake basin and along the research transects - while choosing the spots, the increased intensity of anthropogenic impact (ports, roads with heavy traffic, wastewater discharge zones, built-up areas) was taken into consideration. The river outlets to the lake, where there are ecotonal zones between limnic and fluvial environment, were also taken into account. Analysis of the markers distribution was carried out against the diversity of chemical characteristics of limnic sediments. Ribbon shape of the lake basin and the dominant wind direction provide an opportunity of easy water mixing to a considerable depth. Intensive waving processes cause removal of the matter from the littoral zone towards lake hollows (separated by the underwater tresholds), where the

  16. Hydrogeochemical and stream sediment reconnaissance basic data for Ashland NTMS Quadrangle, Wisconsin; Michigan; Minnesota

    International Nuclear Information System (INIS)

    1979-01-01

    Results of a reconnaissance geochemical survey of the Ashland Quadrangle, Wisconsin; Michigan; Minnesota are reported. Field and laboratory data are presented for 312 groundwater and 383 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwater data indicate that the most promising area for potential uranium mineralization occurs along the Douglas Thrust Fault in northern Douglas County, Wisconsin. The Douglas Fault brings Fond du Lac Formation sediments in contact with Chengwatana volcanics where carbonate-rich water derived from the mafic volcanics enter the arkosic Fond du Lac Formation. Another area of interest surrounds the Bad River Indian Reservation in northern Ashland and Iron Counties. The waters here are produced from red lithic sandstone and are also associated with the Douglas Fault. Water chemistry of these waters appears similar to the waters from the Douglas County area. The stream sediment data are inconclusive because of the extensive cover of glacial deposits. A moderately favorable area is present in a strip along Lake Superior in Douglas County, where sediments are derived from arkoses of the Fond du Lac Formation

  17. Recent changes in the deep-water fish populations of Lake Michigan

    Science.gov (United States)

    Moffett, James W.

    1957-01-01

    The deep-water fish fauna of Lake Michigan consisted of lake trout (Salvelinus namaycush), burbot (Lota lota maculosa), seven species of chubs or deep-water ciscoes (Leucichthys spp.), and the deep-water sculpin (Myoxocephalus quadricornis). Other species occupied the deep-water zone but were not typically part of the fauna.

  18. Shell-free biomass and population dynamics of dreissenids in offshore Lake Michigan, 2001-2003

    Science.gov (United States)

    French, J. R. P.; Adams, J.V.; Craig, J.; Stickel, R.G.; Nichols, S.J.; Fleischer, G.W.

    2007-01-01

    The USGS-Great Lakes Science Center has collected dreissenid mussels annually from Lake Michigan since zebra mussels (Dreissena polymorpha) became a significant portion of the bottom-trawl catch in 1999. For this study, we investigated dreissenid distribution, body mass, and recruitment at different depths in Lake Michigan during 2001-2003. The highest densities of dreissenid biomass were observed from depths of 27 to 46 m. The biomass of quagga mussels (Dreissena bugensis) increased exponentially during 2001-2003, while that of zebra mussels did not change significantly. Body mass (standardized for a given shell length) of both species was lowest from depths of 27 to 37m, highest from 55 to 64 m, and declined linearly at deeper depths during 2001-2003. Recruitment in 2003, as characterized by the proportion of mussels biomass in Lake Michigan.

  19. A short-term look at potential changes in Lake Michigan slimy sculpin diets

    Science.gov (United States)

    French, John R. P.; Stickel, Richard G.; Stockdale, Beth A.; Black, M. Glen

    2010-01-01

    Diporeia hoyi and Mysis relicta are the most important prey items of slimy sculpins (Cottus cognatus) in the Great Lakes. Slimy sculpins were collected from dreissenid-infested bottoms off seven Lake Michigan ports at depths of 27–73 m in fall 2003 to study their lake-wide diets. Relatively large dreissenid biomass occurred at depths of 37- and 46-m. Quagga mussels (Dreissena bugnesis) composed at least 50% of dreissenid biomass at Manistique, Saugatuck, and Sturgeon Bay. Mysis accounted for 82% of the sculpin diet by dry weight at eastern Lake Michigan while Diporeia composed 54–69% of the diet at western Lake Michigan and dominated the diets of slimy sculpins at all sites deeper than 46 m. In northern Lake Michigan, this diet study in new sites showed that slimy sculpin consumed more prey with low energy contents, especially chironomids, than Mysis and Diporeia in shallow sites (depth diet studies on sedentary benthic fishes to be conducted along perimeters of the Great Lakes to observe changes in their diets that may be impacted by changing benthic macroinvertebrate communities.

  20. Comparative analysis of cesium 137 behavior in the lake sediments

    International Nuclear Information System (INIS)

    Zenchenko, S.A.; Zimelis, K.E.

    2002-01-01

    The results for Cs 137 distribution in the lake sediments with different contamination of the organic materials were compared. The role of the horizontal migration is shown for radioactive pollution of the lake sediment

  1. Changes in the Lake Michigan food web following dreissenid mussel invasions: A synthesis

    Science.gov (United States)

    Madenjian, Charles P.; Bunnell, David B.; Warner, David M.; Pothoven, Steven A.; Fahnenstiel, Gary L.; Nalepa, Thomas F.; Vanderploeg, Henry A.; Tsehaye, Iyob; Claramunt, Randall M.; Clark, Richard D

    2015-01-01

    Using various available time series for Lake Michigan, we examined changes in the Lake Michigan food web following the dreissenid mussel invasions and identified those changes most likely attributable to these invasions, thereby providing a synthesis. Expansion of the quagga mussel (Dreissena rostriformis bugensis) population into deeper waters, which began around 2004, appeared to have a substantial predatory effect on both phytoplankton abundance and primary production, with annual primary production in offshore (> 50 m deep) waters being reduced by about 35% by 2007. Primary production likely decreased in nearshore waters as well, primarily due to predatory effects exerted by the quagga mussel expansion. The drastic decline inDiporeia abundance in Lake Michigan during the 1990s and 2000s has been attributed to dreissenid mussel effects, but the exact mechanism by which the mussels were negatively affecting Diporeia abundance remains unknown. In turn, decreased Diporeiaabundance was associated with reduced condition, growth, and/or energy density in alewife (Alosa pseudoharengus), lake whitefish (Coregonus clupeaformis), deepwater sculpin (Myoxocephalus thompsonii), and bloater (Coregonus hoyi). However, lake-wide biomass of salmonines, top predators in the food web, remained high during the 2000s, and consumption of alewives by salmonines actually increased between the 1980–1995 and 1996–2011 time periods. Moreover, abundance of the lake whitefish population, which supports Lake Michigan's most valuable commercial fishery, remained at historically high levels during the 2000s. Apparently, counterbalancing mechanisms operating within the complex Lake Michigan food web have enabled salmonines and lake whitefish to retain relatively high abundances despite reduced primary production.

  2. 76 FR 35106 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2011-06-16

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago..., DHS. ACTION: Final rule. SUMMARY: The Coast Guard is establishing a permanent safety zone from Brandon... Safety Zones; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary...

  3. 77 FR 25595 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Science.gov (United States)

    2012-05-01

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... Safety Zone; Brandon Road Lock and [[Page 25596

  4. Modeling the Sensitivity of Primary Production in Lake Michigan to Nutrient Loads with and without Dreissenid Mussels

    Science.gov (United States)

    Dreissenid (quagga) mussels became established in large numbers in Lake Michigan beginning around 2004. Since then, significant changes have been observed in Lake Michigan open-water chlorophyll and nutrient concentrations, and in primary production. We updated the LM3-Eutro mode...

  5. Chemical composition of Lake Orta sediments

    Directory of Open Access Journals (Sweden)

    Monica BELTRAMI

    2001-08-01

    Full Text Available Lake Orta (18.2 km2, 1.3 km3, 143 m max. depth has been severely polluted since industrialisation of its watershed began in 1926, at which time the lake began to receive industrial effluents containing high concentrations of copper and ammonia. Chromium-, nickel-, and zinc-rich effluents from plating factories have also contributed to pollution levels, and pH -levels dropped below 4.0 as a result of the oxidation of ammonia to nitrates. More than 60 papers have documented the evolution of the chemical characteristics of both water and sediment, and the sudden decline of plankton, as well as benthos and fish. As a remedial action the lake was limed from May 1989 to June 1990 with 10,900 tons of CaCO3. The treatment was immediately effective in raising the pH and decreasing the metal concentrations in the water column, and plankton and fish communities quickly rebounded. However, the chemical characteristics of sediments were influenced by the liming to a much lesser extent. Since 900 tons of copper and the same amount of chromium were contained in the top 10 cm of sediment, it appears likely that the sediment could potentially act as a current and future source of these metals to the water column. This observation has resulted in the implementation of a vigorous monitoring regime to track the post-liming recovery of Lake Orta.

  6. Results of the independent radiological verification survey at 4400 Piehl Road, Ottawa Lake, Michigan (BTO002)

    Energy Technology Data Exchange (ETDEWEB)

    Murray, M.E.; Brown, K.S.

    1996-04-01

    At the request of the US Department of Energy (DOE), a team from Oak Ridge National Laboratory (ORNL) conducted an independent radiological verification survey at Ottawa Lake, Michigan. The survey was performed in November and December of 1994. The purpose of the survey was to verify that the site was remediated to levels below the DOE guidelines for FUSRAP sites. Results of the independent radiological verification survey at Ottawa Lake, Michigan confirm that the residual uranium contamination at the site is below DOE FUSRAP guidelines for unrestricted use.

  7. Sedimentation rates in Lake Pukaki, New Zealand

    International Nuclear Information System (INIS)

    Ditchburn, R.G.; McCabe, W.J.

    1977-10-01

    The layers of Lake Pukaki sediments and their possible relationship to other cyclic events have been considered with a view to determining the rate of sediment deposition. There was no evidence to determine whether the rhytmic layers in the sediments are annual deposits or controlled by flood conditions. In the hope of resolving the question, radiometric dating techniques were applied to sediment cores in which the concentrations of radionuclides such as lead 210 and caesium 137 were measured with respect to depth and then related to some known input pattern. 210 Pb and 137 Cs were determined in all three cores investigated. 147 Pr and 144 Ce were also determined in one of the cores. The 137 Cs measurements indicated sedimentation rates of 14 kg/y/m 2 for one core and 17 kg/y/m 2 for the other two

  8. Field responses of Prunus serotina and Asclepias syriaca to ozone around southern Lake Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J.P. [U.S. Geological Survey and Institute for Environmental Studies, University of Wisconsin, Madison, WI 53706 (United States)]. E-mail: jpbennet@wisc.edu; Jepsen, E.A. [Bureau of Air Management, Wisconsin Department of Natural Resources, Madison, WI 53707 (United States); Roth, J.A. [Bureau of Air Management, Wisconsin Department of Natural Resources, Madison, WI 53707 (United States)

    2006-07-15

    Higher ozone concentrations east of southern Lake Michigan compared to west of the lake were used to test hypotheses about injury and growth effects on two plant species. We measured approximately 1000 black cherry trees and over 3000 milkweed stems from 1999 to 2001 for this purpose. Black cherry branch elongation and milkweed growth and pod formation were significantly higher west of Lake Michigan while ozone injury was greater east of Lake Michigan. Using classification and regression tree (CART) analyses we determined that departures from normal precipitation, soil nitrogen and ozone exposure/peak hourly concentrations were the most important variables affecting cherry branch elongation, and milkweed stem height and pod formation. The effects of ozone were not consistently comparable with the effects of soil nutrients, weather, insect or disease injury, and depended on species. Ozone SUM06 exposures greater than 13 ppm-h decreased cherry branch elongation 18%; peak 1-h exposures greater than 93 ppb reduced milkweed stem height 13%; and peak 1-h concentrations greater than 98 ppb reduced pod formation 11% in milkweed. - Decreased cherry branch elongation, milkweed stem height and pod production, and foliar injury on both species occurred at sites around southern Lake Michigan at ozone exposures of 13 SUM06 ppm-h and 93-98 ppb peak hourly.

  9. Field responses of Prunus serotina and Asclepias syriaca to ozone around southern Lake Michigan

    International Nuclear Information System (INIS)

    Bennett, J.P.; Jepsen, E.A.; Roth, J.A.

    2006-01-01

    Higher ozone concentrations east of southern Lake Michigan compared to west of the lake were used to test hypotheses about injury and growth effects on two plant species. We measured approximately 1000 black cherry trees and over 3000 milkweed stems from 1999 to 2001 for this purpose. Black cherry branch elongation and milkweed growth and pod formation were significantly higher west of Lake Michigan while ozone injury was greater east of Lake Michigan. Using classification and regression tree (CART) analyses we determined that departures from normal precipitation, soil nitrogen and ozone exposure/peak hourly concentrations were the most important variables affecting cherry branch elongation, and milkweed stem height and pod formation. The effects of ozone were not consistently comparable with the effects of soil nutrients, weather, insect or disease injury, and depended on species. Ozone SUM06 exposures greater than 13 ppm-h decreased cherry branch elongation 18%; peak 1-h exposures greater than 93 ppb reduced milkweed stem height 13%; and peak 1-h concentrations greater than 98 ppb reduced pod formation 11% in milkweed. - Decreased cherry branch elongation, milkweed stem height and pod production, and foliar injury on both species occurred at sites around southern Lake Michigan at ozone exposures of 13 SUM06 ppm-h and 93-98 ppb peak hourly

  10. The presence and near-shore transport of human fecal pollution in Lake Michigan beaches

    Science.gov (United States)

    Molloy, S.L.; Liu, L.B.; Phanikumar, M.S.; Jenkins, T.M.; Wong, M.V.; Rose, J.B.; Whitman, R.L.; Shively, D.A.; Nevers, M.B.

    2005-01-01

    The Great Lakes are a source of water for municipal, agricultural and industrial use, and support significant recreation, commercial and sport fishing industries. Every year millions of people visit the 500 plus recreational beaches in the Great Lakes. An increasing public health risk has been suggested with increased evidence of fecal contamination at the shoreline. To investigate the transport and fate of fecal pollution at Great Lakes beaches and the health risk associated with swimming at these beaches, the near-shore waters of Mt Baldy Beach, Lake Michigan and Trail Creek, a tributary discharging into the lake were examined for fecal pollution indicators. A model of surf zone hydrodynamics coupled with a transport model with first-order inactivation of pollutant was used to understand the relative importance of different processes operating in the surf zone (e.g. physical versus biological processes). The Enterococcus human fecal pollution marker, which targets a putative virulence factor, the enterococcal surface protein (esp) in Enterococcus faecium, was detected in 2/28 samples (7%) from the tributaries draining into Lake Michigan and in 6/30 samples (20%) from Lake Michigan beaches. Preliminary analysis suggests that the majority of fecal indicator bactateria variation and water quality changes at the beaches can be explained by inputs from the influential stream and hydrometeorological conditions. Using modeling methods to predict impaired water quality may help reduce potential health threats to recreational visitors.

  11. Lake Michigan Mass Balance Study Post Audit: Integrated, Multi-media PCB Modeling and Forecasting for Lake Trout

    Science.gov (United States)

    The Lake Michigan (LM) Mass Balance Study was conducted to measure and model polychlorinated biphenyls (PCBs) and other anthropogenic substances to gain a better understanding of the transport, fate, and effects of these substances within the system and to aid managers in the env...

  12. Mobility of 137Cs in freshwater lakes: A mass balance and diffusion study of Lake St. Clair, Southeast Michigan, USA

    Science.gov (United States)

    Wang, Jinlong; Baskaran, Mark; Niedermiller, John

    2017-12-01

    Cesium-137 is one of the most widely utilized anthropogenic radionuclides, both as a tracer and chronometer in the environment. Its application as an effective chronometer requires a thorough understanding of its geochemical behavior in aqueous systems. In this study, we collected and analyzed a suite of time-series water samples over a period of 8 months (April - November 2015), for particulate and dissolved 137Cs activities from a watershed in southeast Michigan, USA, using Cu2Fe(CN)6-coated cartridges developed to pre-concentrate dissolved 137Cs. We also conducted a series of laboratory experiments with the natural freshwater sediment samples and water with different chemical composition. There were seasonal variations of both particulate and dissolved 137Cs activities in the watersheds of Lake St. Clair. The distribution coefficients of 137Cs determined over a period of 8 months varied between 0.14 × 105 and 6.1 × 105 mL g-1 (mean: 2.9 × 105 mL g-1). The annual input and export flux of total 137Cs activity via rivers into and out of Lake St. Clair were calculated to be 3.6 × 1010 Bq and 1.6 × 1010 Bq, respectively. The amount of 137Cs derived by diffusion from interstitial pore water to the water column was estimated to be 0.30 × 1010 Bq (8.3% of the total input flux) which is similar to the percentage of 137Cs desorption (13%-20%) from sediment placed in oxic soft water system over a period of 30-106 days. For the same concentrations of NH4+, Mn2+, K+, Mg2+, Ca2+, Na+ and Sr2+ in a distilled water, our lab work showed that the sediment-sorbed 137Cs is displaced by ions in the order NH4+ > Mn2+ > K+ > Mg2+ ≈ Ca2+ > Na+ > Sr2+. In laboratory studies, 137Cs sorbed onto sediment was found to be less mobile in oxic soft water (Kd: 2.0 × 103 mL g-1) and more mobile in anoxic soft water (Kd: 0.2 × 103 mL g-1). In a hard water system, however, there is no significant difference in Kd values for both oxic and anoxic conditions. The sequence of Kd values is

  13. Expansion of Dreissena into offshore waters of Lake Michigan and potential impacts on fish populations

    Science.gov (United States)

    Bunnell, D.B.; Madenjian, C.P.; Holuszko, J.D.; Adams, J.V.; French, J. R. P.

    2009-01-01

    Lake Michigan was invaded by zebra mussels (Dreissena polymorpha) in the late 1980s and then followed by quagga mussels (D. bugensis) around 1997. Through 2000, both species (herein Dreissena) were largely restricted to depths less than 50??m. Herein, we provide results of an annual lake-wide bottom trawl survey in Lake Michigan that reveal the relative biomass and depth distribution of Dreissena between 1999 and 2007 (although biomass estimates from a bottom trawl are biased low). Lake-wide mean biomass density (g/m2) and mean depth of collection revealed no trend between 1999 and 2003 (mean = 0.7??g/m2 and 37??m, respectively). Between 2004 and 2007, however, mean lake-wide biomass density increased from 0.8??g/m2 to 7.0??g/m2, because of increased density at depths between 30 and 110??m, and mean depth of collection increased from 42 to 77??m. This pattern was confirmed by a generalized additive model. Coincident with the Dreissena expansion that occurred beginning in 2004, fish biomass density (generally planktivores) declined 71% between 2003 and 2007. Current understanding of fish population dynamics, however, indicates that Dreissena expansion is not the primary explanation for the decline of fish, and we provide a species-specific account for more likely underlying factors. Nonetheless, future sampling and research may reveal a better understanding of the potential negative interactions between Dreissena and fish in Lake Michigan and elsewhere.

  14. 77 FR 55139 - Safety Zone; Chicago Red Bull Flugtag, Lake Michigan, Chicago, IL

    Science.gov (United States)

    2012-09-07

    ..., Protection of Children from Environmental Health Risks and Safety Risks. This rule is not an economically significant rule and does not create an environmental risk to health or risk to safety that may..., Chicago, IL. The Captain of the Port, Sector Lake Michigan, has determined that the Red Bull Flugtag event...

  15. 76 FR 79536 - Security Zones; Captain of the Port Lake Michigan; Technical Amendment

    Science.gov (United States)

    2011-12-22

    ... Environmental Health Risks and Safety Risks. This rule is not an economically significant rule and does not create an environmental risk to health or risk to safety that may disproportionately affect children...-AA87 Security Zones; Captain of the Port Lake Michigan; Technical Amendment AGENCY: Coast Guard, DHS...

  16. IMPORTANCE OF TEMPERATURE IN MODELLING PCB BIOACCUMULATION IN THE LAKE MICHIGAN FOOD WEB

    Science.gov (United States)

    In most food web models, the exposure temperature of a food web is typically defined using a single spatial compartment. This essentially assumes that the predator and prey are exposed to the same temperature. However, in a large water body such as Lake Michigan, due to the spati...

  17. The age, growth, and bathymetric distribution of Reighard's chub, Leucichthys reighardi koelz, in Lake Michigan

    Science.gov (United States)

    1943-01-01

    Reighard's chub has come to be one of the most important species of the group since the serious decline in abundance of the larger representatives of the genus Leucichthys in Lake Michigan. An understanding of the biology of as many species of chubs as possible is essential if further depletion and the collapse of the fishery are to be prevented.

  18. Comparative survey of petroleum hydrocarbons i lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Wakeham, S G

    1976-11-01

    Hydrocarbon distribution in sediments from three lakes in Washington State were studied and found to be related to the level of human activity in the respective drainage basins. Petroleum hydrocarbon contamination was found in surface sediments of a lake surrounded by a major city, compared to no detectable contamination in a lake located in a National Park.

  19. Lake sediment records of Quaternary climate change

    International Nuclear Information System (INIS)

    Moy, C.

    2013-01-01

    Lake sediments are excellent archives of climate and environmental change. Lakes typically exhibit high sedimentation rates, contain sedimentary components well-suited for a multi-proxy approach, multiple dating methods can be applied, exhibit a broad geographic distribution, and are relatively accessible for study. Furthermore, a number of geochemical techniques can be applied to recontsruct components of the climate system based on the stable isotope geochemistry of carbonate or organic phases preserved and exposed in lacustrine sedimentary cores. Various stable isotope methods can be applied to lacustrine systems and these are a valuable tool that can be used to monitor physical processes (e.g. evaporation), vegetation dynamics within the watershed (C 3 vs C 4 plant distributions), biologic processes (aquatic productivity), all of which can be driven by a regional climate forcing. (author). 31 refs., 11 figs.

  20. Lake sediment records of Quaternary climate change

    International Nuclear Information System (INIS)

    Moy, C.

    2016-01-01

    Lake sediments are excellent archives of climate and environmental change. Lakes typically exhibit high sedimentation rates, contain sedimentary components well-suited for a multi-proxy approach, multiple dating methods can be applied, exhibit a broad geographic distribution, and are relatively accessible for study. Furthermore, a number of geochemical techniques can be applied to recontsruct components of the climate system based on the stable isotope geochemistry of carbonate or organic phases preserved and exposed in lacustrine sedimentary cores. Various stable isotope methods can be applied to lacustrine systems and these are a valuable tool that can be used to monitor physical processes (e.g. evaporation), vegetation dynamics within the watershed (C 3 vs C 4 plant distributions), biologic processes (aquatic productivity), all of which can be driven by a regional climate forcing. (author).

  1. Lake sediment records of Quaternary climate change

    International Nuclear Information System (INIS)

    Moy, C.

    2014-01-01

    Lake sediments are excellent archives of climate and environmental change. Lakes typically exhibit high sedimentation rates, contain sedimentary components well-suited for a multi-proxy approach, multiple dating methods can be applied, exhibit a broad geographic distribution, and are relatively accessible for study. Furthermore, a number of geochemical techniques can be applied to recontsruct components of the climate system based on the stable isotope geochemistry of carbonate or organic phases preserved and exposed in lacustrine sedimentary cores. Various stable isotope methods can be applied to lacustrine systems and these are a valuable tool that can be used to monitor physical processes (e.g. evaporation), vegetation dynamics within the watershed (C 3 vs C 4 plant distributions), biologic processes (aquatic productivity), all of which can be driven by a regional climate forcing. (author)

  2. Lake sediment records of Quaternary climate change

    International Nuclear Information System (INIS)

    Moy, C.

    2015-01-01

    Lake sediments are excellent archives of climate and environmental change. Lakes typically exhibit high sedimentation rates, contain sedimentary components well-suited for a multi-proxy approach, multiple dating methods can be applied, exhibit a broad geographic distribution, and are relatively accessible for study. Furthermore, a number of geochemical techniques can be applied to recontsruct components of the climate system based on the stable isotope geochemistry of carbonate or organic phases preserved and exposed in lacustrine sedimentary cores. Various stable isotope methods can be applied to lacustrine systems and these are a valuable tool that can be used to monitor physical processes (e.g. evaporation), vegetation dynamics within the watershed (C 3 vs C 4 plant distributions), biologic processes (aquatic productivity), all of which can be driven by a regional climate forcing. (author)

  3. Paleoecology of a Northern Michigan Lake and the relationship among climate, vegetation, and Great Lakes water levels

    Science.gov (United States)

    Booth, R.K.; Jackson, S.T.; Thompson, T.A.

    2002-01-01

    We reconstructed Holocene water-level and vegetation dynamics based on pollen and plant macrofossils from a coastal lake in Upper Michigan. Our primary objective was to test the hypothesis that major fluctuations in Great Lakes water levels resulted in part from climatic changes. We also used our data to provide temporal constraints to the mid-Holocene dry period in Upper Michigan. From 9600 to 8600 cal yr B.P. a shallow, lacustrine environment characterized the Mud Lake basin. A Sphagnum-dominated wetland occupied the basin during the mid-Holocene dry period (???8600 to 6600 cal yr B.P.). The basin flooded at 6600 cal yr B.P. as a result of rising water levels associated with the onset of the Nipissing I phase of ancestral Lake Superior. This flooding event occured contemporaneously with a well-documented regional expansion of Tsuga. Betula pollen increased during the Nipissing II phase (4500 cal yr B.P.). Macrofossil evidence from Mud Lake suggests that Betula alleghaniensis expansion was primarily responsible for the rising Betula pollen percentages. Major regional and local vegetational changes were associated with all the major Holocene highstands of the western Great Lakes (Nipissing I, Nipissing II, and Algoma). Traditional interpretations of Great Lakes water-level history should be revised to include a major role of climate. ?? 2002 University of Washington.

  4. Natural radioactivity levels in lake sediment samples

    International Nuclear Information System (INIS)

    Eroglu, H.; Kabadayi, O.

    2013-01-01

    The radioactivity concentrations of nuclides 238 U, 232 Th and 40 K in lake sediments collected from 15 different stations at Altinkaya dam lake and 12 different stations at Derbent dam lake in Turkey were measured using high-resolution gamma-ray spectrometry. The measurement was done using a coaxial HPGe detector system coupled to the Ortec-Dspect jr digital MCA system. The average measured activity concentrations of the nuclides 238 U, 232 Th and 40 K were found to be 19.5, 27.7 and 460 Bq kg -1 in Altinkaya dam, whereas the activity concentrations were 18.8, 25.5 and 365 Bq kg -1 in Derbent dam, respectively. The measured activity concentrations in the present study have been compared with similar measurements from different locations in the world. (authors)

  5. Anthropogenic mercury deposition to arctic lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Hermanson, M.H. [Westchester University, Westchester, PA (United States). Dept. of Health

    1998-01-01

    The history of atmospheric mercury inputs to remote arctic regions can be measured in lake sediment cores using lead-210 chronology. In the investigation, total mercury deposition is measured in sediments from Imitavik and Annak Lakes on the Belcher Islands in southeastern Hudson Bay, an area in the southern Canadian Arctic with no history of local industrial or agricultural sources of contamination. Both lakes received background and atmospheric inputs of mercury while Annak also received mercury from raw domestic sewage from the Hamlet of Sanikiluaq, a growing Inuit community of about 550 established in the late 1960s. Results from Imitavik show that anthropogenic mercury inputs, apparently transported through the atmosphere, began to appear in the mid-eighteenth century, and continued to the 1990s. Annak had a similar mercury history until the late 1960s when disposal of domestic sewage led to increased sediment and contaminant accumulation. The high input of mercury to Annak confirms that Sanikiluaq residents are exposed to mercury through native food sources. 39 refs., 7 figs., 3 tabs.

  6. Paleolimnological sedimentation of organic carbon, nitrogen, phosphorus, fossil pigments, pollen, and diatoms in a hypereutrophic, hardwater lake: a case history of eutrophication

    Energy Technology Data Exchange (ETDEWEB)

    Manny, B.A.; Wetzel, R.G.; Bailey, R.E.

    1977-01-01

    The sediment history of this productive, hardwater lake (Wintergreen Lake in southern Michigan) developed as five periods of increasing eutrophy, each strongly influenced by a hybrid basin morphometry. This morphometry led to higher productivity per unit area by macrophytic plants in littoral waters of the lake than by phytoplankton in pelagic waters. Climate and trophic conditions during each of the five periods between 14,000 and 0 B.P. are postulated.

  7. Factors associated with the deposition of Cladophora on Lake Michigan beaches in 2012

    Science.gov (United States)

    Riley, Stephen C.; Tucker, Taaja R.; Adams, Jean V.; Fogarty, Lisa R.; Lafrancois, Brenda Moraska

    2015-01-01

    Deposition of the macroalgae Cladophora spp. was monitored on 18 beaches around Lake Michigan during 2012 at a high temporal frequency. We observed a high degree of spatial variability in Cladophora deposition among beaches on Lake Michigan, even within local regions, with no clear regional pattern in the intensity of Cladophora deposition. A strong seasonal pattern in Cladophora deposition was observed, with the heaviest deposition occurring during mid-summer. Several beaches exhibited high temporal variability in Cladophora deposition over short time scales, suggesting that drifting algal mats may be extremely dynamic in nearshore environments of the Great Lakes. Cladophora deposition on Lake Michigan beaches was primarily related to the presence of nearshore structures, local population density, and nearshore bathymetry. There was relatively little evidence that waves, winds, or currents were associated with Cladophora deposition on beaches, but this may be due to the relatively poor resolution of existing nearshore hydrodynamic data. Developing a predictive understanding of beach-cast Cladophora dynamics in Great Lakes environments may require both intensive Cladophora monitoring and fine-scale local hydrodynamic modeling efforts.

  8. Lake sediment records of Quaternary climate change

    International Nuclear Information System (INIS)

    Moy, C.

    2012-01-01

    Lake sediment records provide an excellent means to reconstruct past climate and environmental change because they typically provide long, high-resolution and continuous archives of environmental change. Lake sediment records typically exhibit high sedimentation rates (centennial to millennial scale variability is common and annual resolution is possible in some sites), contain sedimentary components well-suited for a multi-proxy approach, multiple dating methods can be applied, tend to exhibit a broad geographic distribution, and are relatively accessible. Furthermore, a number of geochemical techniques can be applied to reconstruct components of the climate system based on the stable isotope geochemistry of carbonate or organic phases preserved and exposed in lacustrine sediment cores. Various stable isotope methods can be applied to lacustrine systems and these are a valuable tool that can be used to monitor physical processes (e.g. evaporation), vegetation dynamics within the watershed (C 3 vs C 4 plant distributions), biologic processes (aquatic productivity), all of which can be driven by a regional climate forcing. (author). 31 refs., 11 figs., 1 tab.

  9. Modeling erosion and accretion along the Illinois Lake Michigan shore using integrated airborne, waterborne and ground-based method

    Science.gov (United States)

    Mwakanyamale, K. E.; Brown, S.; Larson, T. H.; Theuerkauf, E.; Ntarlagiannis, D.; Phillips, A.; Anderson, A.

    2017-12-01

    Sediment distribution at the Illinois Lake Michigan shoreline is constantly changing in response to increased human activities and complex natural coastal processes associated with wave action, short and long term fluctuations in lake level, and the influence of coastal ice. Understanding changes to volume, distribution and thickness of sand along the shore through time, is essential for modeling shoreline changes and predicting changes due to extreme weather events and lake-level fluctuation. The use of helicopter transient electromagnetic (HTEM) method and integration with ground-based and waterborne geophysical and geologic methods provides high resolution spatial rich data required for modeling the extent of erosion and accretion at this dynamic coastal system. Analysis and interpretation of HTEM, ground and waterborne geophysical and geological data identify spatial distribution and thickness of beach and lake-bottom sand. The results provide information on existence of littoral sand deposits and identify coastal hazards such as lakebed down-cutting that occurs in sand-starved areas.

  10. Water-quality characteristics of Michigan's inland lakes, 2001-10

    Science.gov (United States)

    Fuller, L.M.; Taricska, C.K.

    2012-01-01

    The U.S. Geological Survey and the Michigan Department of Environmental Quality (MDEQ) jointly monitored for selected water-quality constituents and properties of inland lakes during 2001–10 as part of Michigan's Lake Water-Quality Assessment program. During 2001–10, 866 lake basins from 729 inland lakes greater than 25 acres were monitored for baseline water-quality conditions and trophic status. This report summarizes the water-quality characteristics and trophic conditions of the monitored lakes throughout the State; the data include vertical-profile measurements, nutrient measurements at three discrete depths, Secchi-disk transparency (SDT) measurements, and chlorophyll a measurements for the spring and summer, with major ions and other chemical indicators measured during the spring at mid-depth and color during the summer from near-surface samples. In about 75 percent of inland lake deep basins (index stations), trophic characteristics were associated with oligotrophic or mesotrophic conditions; 5 percent or less were categorized as hypereutrophic, and 80 percent of hypereutrophic lakes had a maximum depth of 30 feet or less. Comparison of spring and summer measurements shows that water clarity based on SDT measurements were clearer in the spring than in the summer for 63 percent of lakes. For near-surface measurements made in spring, 97 percent of lakes can be considered phosphorus limited and less than half a percent nitrogen limited; for summer measurements, 96 percent of lakes can be considered phosphorus limited and less than half a percent nitrogen limited. Spatial patterns of major ions, alkalinity, and hardness measured in the spring at mid-depth all showed lower values in the Upper Peninsula of Michigan and a southward increase toward the southern areas of the Lower Peninsula, though the location of increase varied by constituent. A spatial analysis of the data based on U.S. Environmental Protection Agency Level III Ecoregions separated potassium

  11. 33 CFR 334.840 - Waters of Lake Michigan south of Northerly Island at entrance to Burnham Park Yacht Harbor...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Waters of Lake Michigan south of Northerly Island at entrance to Burnham Park Yacht Harbor, Chicago, Ill.; danger zone adjacent to airport on... Michigan south of Northerly Island at entrance to Burnham Park Yacht Harbor, Chicago, Ill.; danger zone...

  12. 77 FR 11426 - Safety Zones; Annual Events Requiring Safety Zones in the Captain of the Port Lake Michigan Zone

    Science.gov (United States)

    2012-02-27

    ... Memorial Day; 8:30 p.m. to 10 p.m. (6) Michigan Super Boat Grand Prix; Michigan City, IN. (i) Location. All....m. to 11 p.m. (9) Harborfest Music and Family Festival; Racine, WI. (i) Location. All waters of Lake...

  13. Field responses of Prunus serotina and Asclepias syriaca to ozone around southern Lake Michigan.

    Science.gov (United States)

    Bennett, J P; Jepsen, E A; Roth, J A

    2006-07-01

    Higher ozone concentrations east of southern Lake Michigan compared to west of the lake were used to test hypotheses about injury and growth effects on two plant species. We measured approximately 1000 black cherry trees and over 3000 milkweed stems from 1999 to 2001 for this purpose. Black cherry branch elongation and milkweed growth and pod formation were significantly higher west of Lake Michigan while ozone injury was greater east of Lake Michigan. Using classification and regression tree (CART) analyses we determined that departures from normal precipitation, soil nitrogen and ozone exposure/peak hourly concentrations were the most important variables affecting cherry branch elongation, and milkweed stem height and pod formation. The effects of ozone were not consistently comparable with the effects of soil nutrients, weather, insect or disease injury, and depended on species. Ozone SUM06 exposures greater than 13 ppm-h decreased cherry branch elongation 18%; peak 1-h exposures greater than 93 ppb reduced milkweed stem height 13%; and peak 1-h concentrations greater than 98 ppb reduced pod formation 11% in milkweed.

  14. A mercury transport and fate model (LM2-mercury) for mass budget assessment of mercury cycling in Lake Michigan

    Science.gov (United States)

    LM2-Mercury, a mercury mass balance model, was developed to simulate and evaluate the transport, fate, and biogeochemical transformations of mercury in Lake Michigan. The model simulates total suspended solids (TSS), disolved organic carbon (DOC), and total, elemental, divalent, ...

  15. Spawning habitat unsuitability: an impediment to cisco rehabilitation in Lake Michigan?

    Science.gov (United States)

    Madenjian, Charles P.; Rutherford, Edward S.; Blouin, Marc A.; Sederberg, Bryan J.; Elliott, Jeff R.

    2011-01-01

    The cisco Coregonus artedi was one of the most important native prey fishes in Lake Michigan and in the other four Laurentian Great Lakes. Most of the cisco spawning in Lake Michigan was believed to have occurred in Green Bay. The cisco population in Lake Michigan collapsed during the 1950s, and the collapse was attributed in part to habitat degradation within Green Bay. Winter water quality surveys of lower Green Bay during the 1950s and 1960s indicated that the bottom dissolved oxygen (DO) concentration was less than 2 mg/L throughout much of the lower bay, and most cisco eggs would not successfully hatch at such low DO concentrations. To determine present-day spawning habitat suitability in lower Green Bay, we compared cisco egg survival in lower Green Bay with survival at a reference site (St. Marys River, Michigan–Ontario) during 2009. We also conducted winter water quality surveys in lower Green Bay and the St. Marys River during 2009 and 2010. Cisco egg survival in lower Green Bay averaged 65.3%, which was remarkably similar to and not significantly different from the mean at the St. Marys River site (64.0%). Moreover, the lowest bottom DO concentrations recorded during the winter surveys were 11.2 mg/L in lower Green Bay and 12.7 mg/L in the St. Marys River. These relatively high DO concentrations would not be expected to have any negative effect on cisco egg survival. We conclude that winter water quality conditions in lower Green Bay were suitable for successful hatching of cisco eggs and that water quality during the egg incubation period did not represent an impediment to cisco rehabilitation in Lake Michigan. Our approach to determining spawning habitat suitability for coregonids would be applicable to other aquatic systems.

  16. A conceptual framework for Lake Michigan coastal/nearshore ecosystems, with application to Lake Michigan Lakewide Management Plan (LaMP) objectives

    Science.gov (United States)

    Seelbach, Paul W.; Fogarty, Lisa R.; Bunnell, David Bo; Haack, Sheridan K.; Rogers, Mark W.

    2013-01-01

    The Lakewide Management Plans (LaMPs) within the Great Lakes region are examples of broad-scale, collaborative resource-management efforts that require a sound ecosystems approach. Yet, the LaMP process is lacking a holistic framework that allows these individual actions to be planned and understood within the broader context of the Great Lakes ecosystem. In this paper we (1) introduce a conceptual framework that unifies ideas and language among Great Lakes managers and scientists, whose focus areas range from tributary watersheds to open-lake waters, and (2) illustrate how the framework can be used to outline the geomorphic, hydrologic biological, and societal processes that underlie several goals of the Lake Michigan LaMP, thus providing a holistic and fairly comprehensive roadmap for tackling these challenges. For each selected goal, we developed a matrix that identifies the key ecosystem processes within the cell for each lake zone and each discipline; we then provide one example where a process is poorly understood and a second where a process is understood, but its impact or importance is unclear. Implicit in these objectives was our intention to highlight the importance of the Great Lakes coastal/nearshore zone. Although the coastal/nearshore zone is the important linkage zone between the watershed and open-lake zones—and is the zone where most LaMP issues are focused--scientists and managers have a relatively poor understanding of how the coastal/nearshore zone functions. We envision follow-up steps including (1) collaborative development of a more detailed and more complete conceptual model of how (and where) identified processes are thought to function, and (2) a subsequent gap analysis of science and monitoring priorities.

  17. Ecosystem transformations of the Laurentian Great Lake Michigan by nonindigenous biological invaders.

    Science.gov (United States)

    Cuhel, Russell L; Aguilar, Carmen

    2013-01-01

    Lake Michigan, a 58,000-km(2) freshwater inland sea, is large enough to have persistent basin-scale circulation yet small enough to enable development of approximately balanced budgets for water, energy, and elements including carbon and silicon. Introduction of nonindigenous species-whether through invasion, intentional stocking, or accidental transplantation-has transformed the lake's ecosystem function and habitat structure. Of the 79 nonindigenous species known to have established reproductive populations in the lake, only a few have brought considerable ecological pressure to bear. Four of these were chosen for this review to exemplify top-down (sea lamprey, Petromyzon marinus), middle-out (alewife, Alosa pseudoharengus), and bottom-up (the dreissenid zebra and quagga mussels, Dreissena polymorpha and Dreissena rostriformis bugensis, respectively) transformations of Lake Michigan ecology, habitability, and ultimately physical environment. Lampreys attacked and extirpated indigenous lake trout, the top predator. Alewives outcompeted native planktivorous fish and curtailed invertebrate populations. Dreissenid mussels-especially quagga mussels, which have had a much greater impact than the preceding zebra mussels-moved ecosystem metabolism basin-wide from water column to bottom dominance and engineered structures throughout the lake. Each of these non indigenous species exerted devastating effects on commercial and sport fisheries through ecosystem structure modification.

  18. [Limnology of high mountain tropical lake, in Ecuador: characteristics of sediments and rate of sedimentation].

    Science.gov (United States)

    Gunkel, Günter

    2003-06-01

    Equatorial high mountain lakes are a special type of lake occurring mainly in the South American Andes as well as in Central Africa and Asia. They occur at altitudes of a few thousand meters above sea level and are cold-water lakes (limnological study was therefore undertaken at Lake San Pablo, Ecuador, to analyze the basic limnological processes of the lake, which has a tendency for eutrophication. Sediment quality of San Pablo Lake is given under consideration of horizontal and vertical distribution using sediment cores. Significance of sediments for eutrophication process of lakes is demonstrated using phosphorus concentration of sediments as well as the phosphorus retention capacity of the sediments by ratio Fe/P. Dating of the sediments is done using 137Cs and 210Pb, but the activity of 137Cs in the sediment was very low nearly at the detection level. Sedimentation rate is determined to be 3.5 mm/year and the sediment cores represent about 110 years. P concentration of the sediments is high (approximately 5 g/kg dry substance), and P retention capacity by Fe is insufficient (Fe/P = 4). The sediment quality did not change significantly during the past decades, and the trophic state of San Pablo Lake was already less or more eutrophic 110 years ago. The contamination of the lake sediments by heavy metals is insignificant.

  19. Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

    Science.gov (United States)

    Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

    2016-06-01

    Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Examining Ecological and Ecosystem Level Impacts of Aquatic Invasive Species in Lake Michigan Using An Ecosystem Productivity Model, LM-Eco

    Science.gov (United States)

    Ecological and ecosystem-level impacts of aquatic invasive species in Lake Michigan were examined using the Lake Michigan Ecosystem Model (LM-Eco). The LM-Eco model includes a detailed description of trophic levels and their interactions within the lower food web of Lake Michiga...

  1. Urban microbial ecology of a freshwater estuary of Lake Michigan.

    Science.gov (United States)

    Fisher, Jenny C; Newton, Ryan J; Dila, Deborah K; McLellan, Sandra L

    Freshwater estuaries throughout the Great Lakes region receive stormwater runoff and riverine inputs from heavily urbanized population centers. While human and animal feces contained in this runoff are often the focus of source tracking investigations, non-fecal bacterial loads from soil, aerosols, urban infrastructure, and other sources are also transported to estuaries and lakes. We quantified and characterized this non-fecal urban microbial component using bacterial 16S rRNA gene sequences from sewage, stormwater, rivers, harbor/estuary, and the lake surrounding Milwaukee, WI, USA. Bacterial communities from each of these environments had a distinctive composition, but some community members were shared among environments. We used a statistical biomarker discovery tool to identify the components of the microbial community that were most strongly associated with stormwater and sewage to describe an "urban microbial signature," and measured the presence and relative abundance of these organisms in the rivers, estuary, and lake. This urban signature increased in magnitude in the estuary and harbor with increasing rainfall levels, and was more apparent in lake samples with closest proximity to the Milwaukee estuary. The dominant bacterial taxa in the urban signature were Acinetobacter, Aeromonas , and Pseudomonas , which are organisms associated with pipe infrastructure and soil and not typically found in pelagic freshwater environments. These taxa were highly abundant in stormwater and sewage, but sewage also contained a high abundance of Arcobacter and Trichococcus that appeared in lower abundance in stormwater outfalls and in trace amounts in aquatic environments. Urban signature organisms comprised 1.7% of estuary and harbor communities under baseflow conditions, 3.5% after rain, and >10% after a combined sewer overflow. With predicted increases in urbanization across the Great Lakes, further alteration of freshwater communities is likely to occur with potential

  2. Urban microbial ecology of a freshwater estuary of Lake Michigan

    Directory of Open Access Journals (Sweden)

    Jenny C. Fisher

    2015-07-01

    Full Text Available Abstract Freshwater estuaries throughout the Great Lakes region receive stormwater runoff and riverine inputs from heavily urbanized population centers. While human and animal feces contained in this runoff are often the focus of source tracking investigations, non-fecal bacterial loads from soil, aerosols, urban infrastructure, and other sources are also transported to estuaries and lakes. We quantified and characterized this non-fecal urban microbial component using bacterial 16S rRNA gene sequences from sewage, stormwater, rivers, harbor/estuary, and the lake surrounding Milwaukee, WI, USA. Bacterial communities from each of these environments had a distinctive composition, but some community members were shared among environments. We used a statistical biomarker discovery tool to identify the components of the microbial community that were most strongly associated with stormwater and sewage to describe an “urban microbial signature,” and measured the presence and relative abundance of these organisms in the rivers, estuary, and lake. This urban signature increased in magnitude in the estuary and harbor with increasing rainfall levels, and was more apparent in lake samples with closest proximity to the Milwaukee estuary. The dominant bacterial taxa in the urban signature were Acinetobacter, Aeromonas, and Pseudomonas, which are organisms associated with pipe infrastructure and soil and not typically found in pelagic freshwater environments. These taxa were highly abundant in stormwater and sewage, but sewage also contained a high abundance of Arcobacter and Trichococcus that appeared in lower abundance in stormwater outfalls and in trace amounts in aquatic environments. Urban signature organisms comprised 1.7% of estuary and harbor communities under baseflow conditions, 3.5% after rain, and >10% after a combined sewer overflow. With predicted increases in urbanization across the Great Lakes, further alteration of freshwater communities is

  3. Urban microbial ecology of a freshwater estuary of Lake Michigan

    Science.gov (United States)

    Fisher, Jenny C.; Newton, Ryan J.; Dila, Deborah K.

    2015-01-01

    Freshwater estuaries throughout the Great Lakes region receive stormwater runoff and riverine inputs from heavily urbanized population centers. While human and animal feces contained in this runoff are often the focus of source tracking investigations, non-fecal bacterial loads from soil, aerosols, urban infrastructure, and other sources are also transported to estuaries and lakes. We quantified and characterized this non-fecal urban microbial component using bacterial 16S rRNA gene sequences from sewage, stormwater, rivers, harbor/estuary, and the lake surrounding Milwaukee, WI, USA. Bacterial communities from each of these environments had a distinctive composition, but some community members were shared among environments. We used a statistical biomarker discovery tool to identify the components of the microbial community that were most strongly associated with stormwater and sewage to describe an “urban microbial signature,” and measured the presence and relative abundance of these organisms in the rivers, estuary, and lake. This urban signature increased in magnitude in the estuary and harbor with increasing rainfall levels, and was more apparent in lake samples with closest proximity to the Milwaukee estuary. The dominant bacterial taxa in the urban signature were Acinetobacter, Aeromonas, and Pseudomonas, which are organisms associated with pipe infrastructure and soil and not typically found in pelagic freshwater environments. These taxa were highly abundant in stormwater and sewage, but sewage also contained a high abundance of Arcobacter and Trichococcus that appeared in lower abundance in stormwater outfalls and in trace amounts in aquatic environments. Urban signature organisms comprised 1.7% of estuary and harbor communities under baseflow conditions, 3.5% after rain, and >10% after a combined sewer overflow. With predicted increases in urbanization across the Great Lakes, further alteration of freshwater communities is likely to occur with

  4. Seasonal development of phytoplankton populations in offshore Lake Michigan in 1975

    International Nuclear Information System (INIS)

    Parker, J.I.; Conway, H.L.; Yaguchi, E.M.

    1975-01-01

    Relationships between phytoplankton bloom sequences and environmental factors that may account for seasonal variations have not been thoroughly evaluated in Lake Michigan. We investigated the seasonal periodicity of phytoplankton in the offshore water from April to December, 1975. The seasonal distributions of phytoplankton biomass, chlorophyll a, and primary productivity per unit of lake surface area were measured at station 5. These measurements demonstrated a bimodal seasonal distribution, with maxima occurring in June and October. Previous investigators have shown that the seasonal periodicity was unimodal, with a summer maximum. Our observations demonstrated year to year variations in this abundance pattern

  5. Heavy metal pollution assessment in the sediments of lake Chad ...

    African Journals Online (AJOL)

    Sediments were collected from Dumba and KwataYobe of Lake Chad, Nigerian Sector.The aim was to assess the pollution statusof the sediments of the lake. The concentration of heavy metals, Cadmium (Cd), Chromium (Cr), Copper (Cu), Iron (Fe), Manganese (Mn), Nickel (Ni), lead (Pb), Z (Zn) and Arsenic (As) were ...

  6. Spatial distribution of radionuclides in Lake Michigan biota near the Big Rock Point Nuclear Plant

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Yaguchi, E.M.; Nelson, D.M.; Marshall, J.S.

    1974-01-01

    A survey was made of four groups of biota in the vicinity of the Big Rock Point Nuclear Plant near Charlevoix, Michigan, to determine their usefulness in locating possible sources of plutonium and other radionuclides to Lake Michigan. This 70 MW boiling-water reactor, located on the Lake Michigan shoreline, was chosen because its fuel contains recycled plutonium, and because it routinely discharges very low-level radioactive wastes into the lake. Samples of crayfish (Orconectes sp.), green algae (Chara sp. and Cladophora sp.), and an aquatic macrophyte (Potamogeton sp.) were collected in August 1973, at varying distances from the discharge and analyzed for 239 240 Pu, 90 Sr, and five gamma-emitting radionuclides. Comparison samples of reactor waste solution have also been analyzed for these radionuclides. Comparisons of the spatial distributions of the extremely low radionuclide concentrations in biota clearly indicated that 137 Cs, 134 Cs, 65 Zn, and 60 Co were released from the reactor; their concentrations decreased exponentially with increasing distance from the discharge. Conversely, concentrations of 239 240 Pu, 95 Zr, and 90 Sr showed no correlation with distance, suggesting any input from Big Rock was insignificant with respect to the atmospheric origin of these isotopes. The significance of these results is discussed, particularly with respect to current public debate over the possibility of local environmental hazards associated with the use of plutonium as a nuclear fuel. (U.S.)

  7. Trace element composition in sediments of the Amazonian Lake Cristalino

    International Nuclear Information System (INIS)

    Ferraz, E.S.B.; Fernandes, E.A.N.

    1995-01-01

    Lake Cristalino is a small lake adjacent to the Negro River near Manaus and not far from the Amazonas River, in the central Amazon basin. The lake is fed seasonally by waters of the Negro River, a blackwater river with low levels of nutrients and suspended solids (7 g m -3 ). However, some investigations have established that Lake Cristalino has a high sedimentation rate (0.4-0.5 cm year -l ) similar to those in the alluvial floodplain lakes of the Amazonas River (suspended solids 200-300 g m -3 ). Sediment cores were taken during the low-water period and the trace-element composition and the natural radioactivity in the lake were examined. The results show a core (31 cm length) relatively uniform in concentrations of trace elements (Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Sc, Sm, Ta, Tb, Th, Yb and Zn), and the presence of 137 Cs in the first half. Concentrations of trace elements in Lake Cristalino sediments were not correlated with concentrations in the sediments of its parent river, the Negro River, or with concentrations in soils of the local area. However, significant correlation was found between the sediments of the lake and those of the Amazonas River. On the basis of these results, and water-level data at Manaus port, it is concluded that the lake occasionally receives variable amounts of sediment from the Amazonas River. 10 refs., 2 tabs., 2 figs

  8. Varves in lake sediments - a review

    Science.gov (United States)

    Zolitschka, Bernd; Francus, Pierre; Ojala, Antti E. K.; Schimmelmann, Arndt

    2015-06-01

    Downcore counting of laminations in varved sediments offers a direct and incremental dating technique for high-resolution climatic and environmental archives with at least annual and sometimes even seasonal resolution. The pioneering definition of varves by De Geer (1912) had been restricted to rhythmically deposited proglacial clays. One century later the meaning of 'varve' has been expanded to include all annually deposited laminae in terrestrial and marine settings. Under favourable basin configurations and environmental conditions, limnic varves are formed due to seasonality of depositional processes from the lake's water column and/or transport from the catchment area. Subsequent to deposition of topmost laminae, the physical preservation of the accumulating varved sequence requires the sustained absence of sediment mixing, for example via wave action or macrobenthic bioturbation. Individual (sub)laminae in varved lake sediments typically express contrasting colours, always differ in terms of their organic, chemical and/or mineralogical compositions, and often also differ with regard to grain-size. Various predominating climatic and depositional conditions may result in clastic, biogenic or endogenic (incl. evaporitic) varved sediments and their mixtures. To reliably establish a varve chronology, the annual character of laminations needs to be determined and verified in a multidisciplinary fashion. Sources and influences of possible errors in varve chronologies are best determined and constrained by repeated varve counts, and by including radioisotopes and correlation with historically documented events. A well-established varve chronology greatly enhances the scientific value of laminated limnic archives by securely anchoring the wealth of multi-proxy palaeoenvironmental information in the form of time-series for multidisciplinary investigations. Applications of varved records are discussed with special reference to advances since the 1980s. These span fields

  9. Status and trends of prey fish populations in Lake Michigan, 2013

    Science.gov (United States)

    Madenjian, Charles P.; Bunnell, David B.; Desorcie, Timothy J.; Kostich, Melissa Jean; Armenio, Patricia M.; Adams, Jean V.

    2015-01-01

    The U.S. Geological Survey Great Lakes Science Center has conducted lake-wide surveys of the fish community in Lake Michigan each fall since 1973 using standard 12-m bottom trawls towed along contour at depths of 9 to 110 m at each of seven index transects. The resulting data on relative abundance, size and age structure, and condition of individual fishes are used to estimate various population parameters that are in turn used by state and tribal agencies in managing Lake Michigan fish stocks. All seven established index transects of the survey were completed in 2013. The survey provides relative abundance and biomass estimates between the 5-m and 114-m depth contours of the lake (herein, lake-wide) for prey fish populations, as well as burbot, yellow perch, and the introduced dreissenid mussels. Lake-wide biomass of alewives in 2013 was estimated at 29 kilotonnes (kt, 1 kt = 1000 metric tonnes), which was more than three times the 2012 estimate. However, the unusually high standard error associated with the 2013 estimate indicated no significant increase in lake-wide biomass between 2012 and 2013. Moreover, the age distribution of alewives remained truncated with no alewife exceeding an age of 5. The population of age-1 and older alewives was dominated (i.e., 88%) by the 2010 and 2012 year-classes. Record low biomass was observed for deepwater sculpin (1.3 kt) and ninespine stickleback (0.004 kt) in 2013, while bloater (1.6 kt) and rainbow smelt (0.2 kt) biomasses remained at low levels. Slimy sculpin lake-wide biomass was 0.32 kt in 2013, marking the fourth consecutive year of a decline. The 2013 biomass of round goby was estimated at 10.9 kt, which represented the peak estimate to date. Burbot lake-wide biomass (0.4 kt in 2013) has remained below 3 kt since 2001. Numeric density of age-0 yellow perch (i.e., fish per ha, which is indicative of a relatively poor year-class. Lake-wide biomass estimate of dreissenid mussels in 2013 was 23.2 kt. Overall, the total

  10. 76 FR 41065 - Safety Zones; Annual Events Requiring Safety Zones in the Captain of the Port Lake Michigan Zone

    Science.gov (United States)

    2011-07-13

    ... Federal holidays and the U.S. Coast Guard Sector Lake Michigan, 2420 South Lincoln Memorial Drive...'' N, 088[deg]03'50'' W (NAD 83). (2) Enforcement date and time. The Sunday before Memorial Day; 8:30 p....m. to 11 p.m. (i) Harborfest Music and Family Festival; Racine, WI. (1) Location. All waters of Lake...

  11. Basin-scale simulation of current and potential climate changed hydrologic conditions in the Lake Michigan Basin, United States

    Science.gov (United States)

    Christiansen, Daniel E.; Walker, John F.; Hunt, Randall J.

    2014-01-01

    The Great Lakes Restoration Initiative (GLRI) is the largest public investment in the Great Lakes in two decades. A task force of 11 Federal agencies developed an action plan to implement the initiative. The U.S. Department of the Interior was one of the 11 agencies that entered into an interagency agreement with the U.S. Environmental Protection Agency as part of the GLRI to complete scientific projects throughout the Great Lakes basin. The U.S. Geological Survey, a bureau within the Department of the Interior, is involved in the GLRI to provide scientific support to management decisions as well as measure progress of the Great Lakes basin restoration efforts. This report presents basin-scale simulated current and forecast climatic and hydrologic conditions in the Lake Michigan Basin. The forecasts were obtained by constructing and calibrating a Precipitation-Runoff Modeling System (PRMS) model of the Lake Michigan Basin; the PRMS model was calibrated using the parameter estimation and uncertainty analysis (PEST) software suite. The calibrated model was used to evaluate potential responses to climate change by using four simulated carbon emission scenarios from eight general circulation models released by the World Climate Research Programme’s Coupled Model Intercomparison Project phase 3. Statistically downscaled datasets of these scenarios were used to project hydrologic response for the Lake Michigan Basin. In general, most of the observation sites in the Lake Michigan Basin indicated slight increases in annual streamflow in response to future climate change scenarios. Monthly streamflows indicated a general shift from the current (2014) winter-storage/snowmelt-pulse system to a system with a more equally distributed hydrograph throughout the year. Simulated soil moisture within the basin illustrates that conditions within the basin are also expected to change on a monthly timescale. One effect of increasing air temperature as a result of the changing

  12. Evaluating the importance of abiotic and biotic drivers on Bythotrephes biomass in Lakes Superior and Michigan

    Science.gov (United States)

    Keeler, Kevin M.; Bunnell, David B.; Diana, James S.; Adams, Jean V.; Mychek-Londer, Justin G.; Warner, David M.; Yule, Daniel; Vinson, Mark

    2015-01-01

    The ability of planktivorous fishes to exert top-down control on Bythotrephes potentially has far-reaching impacts on aquatic food-webs, given previously described effects of Bythotrephes on zooplankton communities. We estimated consumption of Bythotrephes by planktivorous and benthivorous fishes, using bioenergetics and daily ration models at nearshore (18 m), intermediate (46 m), and offshore (110 m) depths along one western Lake Superior transect (April, and September-November) and two northern Lake Michigan transects (April, July, September). In Lake Superior, consumption (primarily by cisco Coregonus artedi) exceeded Bythotrephes production at all offshore sites in September-November (up to 396% of production consumed) and at the intermediate site in November (842%) with no evidence of consumption nearshore. By comparing Bythotrephes biomass following months of excessive consumption, we conservatively concluded that top-down control was evident only at the offshore site during September-October. In Lake Michigan, consumption by fishes (primarily alewife Alosa pseudoharengus) exceeded production at nearshore sites (up to 178%), but not in deeper sites (additive models, temperature, and not fish consumption, not zooplankton prey density, best explained variability in Bythotrephes biomass. The non-linear pattern revealed Bythotrephes to increase with temperature up to 16 °C, and then decline between 16 and 23 °C. We discuss how temperature likely has direct negative impacts on Bythotrephes when temperatures near 23 °C, but speculate that predation also contributes to declining biomass when temperatures exceed 16 °C.

  13. Lake sediments record prehistoric lead pollution related to early copper production in North America.

    Science.gov (United States)

    Pompeani, David P; Abbott, Mark B; Steinman, Byron A; Bain, Daniel J

    2013-06-04

    The mining and use of copper by prehistoric people on Michigan's Keweenaw Peninsula is one of the oldest examples of metalworking. We analyzed the concentration of lead, titanium, magnesium, iron, and organic matter in sediment cores recovered from three lakes located near mine pits to investigate the timing, location, and magnitude of ancient copper mining pollution. Lead concentrations were normalized to lithogenic metals and organic matter to account for processes that can influence natural (or background) lead delivery. Nearly simultaneous lead enrichments occurred at Lake Manganese and Copper Falls Lake ∼8000 and 7000 years before present (yr BP), indicating that copper extraction occurred concurrently in at least two locations on the peninsula. The poor temporal coherence among the lead enrichments from ∼6300 to 5000 yr BP at each lake suggests that the focus of copper mining and annealing shifted through time. In sediment younger than ∼5000 yr BP, lead concentrations remain at background levels at all three lakes, excluding historic lead increases starting ∼150 yr BP. Our work demonstrates that lead emissions associated with both the historic and Old Copper Complex tradition are detectable and can be used to determine the temporal and geographic pattern of metal pollution.

  14. Multi-pathogen waterborne disease outbreak associated with a dinner cruise on Lake Michigan.

    Science.gov (United States)

    Serdarevic, F; Jones, R C; Weaver, K N; Black, S R; Ritger, K A; Guichard, F; Dombroski, P; Emanuel, B P; Miller, L; Gerber, S I

    2012-04-01

    We report an outbreak associated with a dinner cruise on Lake Michigan. This took place on the same day as heavy rainfall, which resulted in 42·4 billion liters of rainwater and storm runoff containing highly diluted sewage being released into the lake. Of 72 cruise participants, 41 (57%) reported gastroenteritis. Stool specimens were positive for Shigella sonnei (n=3), Giardia (n=3), and Cryptosporidium (n=2). Ice consumption was associated with illness (risk ratio 2·2, P=0·011). S. sonnei was isolated from a swab obtained from the one of the boat's ice bins. Environmental inspection revealed conditions and equipment that could have contributed to lake water contaminating the hose used to load potable water onto the boat. Knowledge of water holding and distribution systems on boats, and of potential risks associated with flooding and the release of diluted sewage into large bodies of water, is crucial for public health guidance regarding recreational cruises.

  15. Predicting lake trophic state by relating Secchi-disk transparency measurements to Landsat-satellite imagery for Michigan inland lakes, 2003-05 and 2007-08

    Science.gov (United States)

    Fuller, L.M.; Jodoin, R.S.; Minnerick, R.J.

    2011-01-01

    Inland lakes are an important economic and environmental resource for Michigan. The U.S. Geological Survey and the Michigan Department of Natural Resources and Environment have been cooperatively monitoring the quality of selected lakes in Michigan through the Lake Water Quality Assessment program. Sampling for this program began in 2001; by 2010, 730 of Michigan’s 11,000 inland lakes are expected to have been sampled once. Volunteers coordinated by the Michigan Department of Natural Resources and Environment began sampling lakes in 1974 and continue to sample (in 2010) approximately 250 inland lakes each year through the Michigan Cooperative Lakes Monitoring Program. Despite these sampling efforts, it still is impossible to physically collect measurements for all Michigan inland lakes; however, Landsat-satellite imagery has been used successfully in Minnesota, Wisconsin, Michigan, and elsewhere to predict the trophic state of unsampled inland lakes greater than 20 acres by producing regression equations relating in-place Secchi-disk measurements to Landsat bands. This study tested three alternatives to methods previously used in Michigan to improve results for predicted statewide Trophic State Index (TSI) computed from Secchi-disk transparency (TSI (SDT)). The alternative methods were used on 14 Landsat-satellite scenes with statewide TSI (SDT) for two time periods (2003– 05 and 2007–08). Specifically, the methods were (1) satellitedata processing techniques to remove areas affected by clouds, cloud shadows, haze, shoreline, and dense vegetation for inland lakes greater than 20 acres in Michigan; (2) comparison of the previous method for producing a single open-water predicted TSI (SDT) value (which was based on an area of interest (AOI) and lake-average approach) to an alternative Gethist method for identifying open-water areas in inland lakes (which follows the initial satellite-data processing and targets the darkest pixels, representing the deepest water

  16. 90% Below 10m: Summer Biomass and Productivity are Invisible to Satellites and Surface Transects in Modern Lake Michigan

    Science.gov (United States)

    Cuhel, R. L.; Aguilar, C.

    2013-12-01

    Deep biomass maxima, often identified through in vivo chlorophyll fluorescence profiles (DCM or deep chlorophyll maximum), have been common 'forever' in Lake Michigan. Usually present in the upper thermocline zone of 15-25m, summer DCM populations were characteristically dominated by diatoms. Increased light transmission in quagga mussel (QM) engineered Lake Michigan waters now has enabled phytoplankton to proliferate in discrete layers as deep as 50m. Instances of multiple fluorescence maxima and transmission minima, often not coincident, document the habitat diversity available in clear, often sequentially stratified offshore waters and MidLake Reef Complex locations. Phytoplankton population structure has also changed, and diatoms have become a much smaller component of algal biomass. Discrete layers of chromatically adapted picoplankton now dominate the deepest biomass maxima. Photosynthetic characteristics differ substantially among leading edge, principal biomass or fluorescence, and deep trailing edge populations. Saturation coefficients are often as low as 25 uEin/m2/sec, or 1% of midday summer surface radiance. In vivo fluorescence is only loosely related to biomass, which is greatest in shallower zones of beam transmission minima. On a daily basis, areal primary productivity post-QM is less than half of previous levels, and seasonality has been muted. Spring bloom enhancement no longer exists, and the depth zone of maximum productivity is 10-20m deeper than during the diatom epoch. Altered phytoplankton community structure and decreased productivity left strong signals in biogeochemical time series measurements. A clear discontinuity in silicate cycling indicates dampened diatom productivity and consequently lower silica loss through deposition and burial. Porewater analysis pre- and post-QM shows evidence of reduced organic sedimentation overall, with an especially strong signal in decreased potential silicate efflux. Biogeochemical consequences include

  17. Conditions affecting the release of phosphorus from surface lake sediments.

    Science.gov (United States)

    Christophoridis, Christophoros; Fytianos, Konstantinos

    2006-01-01

    Laboratory studies were conducted to determine the effect of pH and redox conditions, as well as the effect of Fe, Mn, Ca, Al, and organic matter, on the release of ortho-phosphates in lake sediments taken from Lakes Koronia and Volvi (Northern Greece). Results were evaluated in combination with experiments to determine P fractionation in the sediment. The study revealed the major effect of redox potential and pH on the release of P from lake sediments. Both lakes showed increased release rates under reductive conditions and high pH values. The fractionation experiments revealed increased mobility of the reductive P fraction as well as of the NaOH-P fraction, indicating participation of both fractions in the overall release of sediment-bound P, depending on the prevailing environmental conditions. The results were assessed in combination with the release patterns of Fe, Mn, Ca, Al, and organic matter, enabling the identification of more specific processes of P release for each lake. The basic release patterns included the redox induced reductive dissolution of P-bearing metal oxides and the competitive exchange of phosphate anions with OH- at high pH values. The formation of an oxidized surface microlayer under oxic conditions acted as a protective film, preventing further P release from the sediments of Lake Volvi, while sediments from Lake Koronia exhibited a continuous and increased tendency to release P under various physicochemical conditions, acting as a constant source of internal P loading.

  18. Sediment characteristics and wind-induced sediment dynamics in shallow Lake Markermeer, the Netherlands

    NARCIS (Netherlands)

    Kelderman, P.; Ang'weya, R.O.; De Rozari, P.; Vijverberg, T.

    2012-01-01

    In 2007/08, a study was undertaken on the sediment dynamics in shallow Lake Markermeer (the Netherlands). Firstly, sediment characteristics were determined at 49 sites in the lake. Parameters such as median grain size and loss on ignition showed a spatial as well as water depth related pattern,

  19. Groundwater flux and nutrient loading in the northeast section of Bear Lake, Muskegon County, Michigan, 2015

    Science.gov (United States)

    Totten, Alexander R.; Maurer, Jessica A.; Duris, Joseph W.

    2017-11-30

    Bear Lake in North Muskegon, Michigan, is listed as part of the Muskegon Lake area of concern as designated by the U.S. Environmental Protection Agency. This area of concern was designated as a result of eutrophication and beneficial use impairments. On the northeast end of Bear Lake, two man-made retention ponds (Willbrandt Pond East and Willbrandt Pond West), formerly used for celery farming, may contribute nutrients to Bear Lake. Willbrandt Ponds (East and West) were previously muck fields that were actively used for celery farming from the early 1900s until 2002. The restoration and reconnection of the Willbrandt Ponds into Bear Lake prompted concerns of groundwater nutrient loading into Bear Lake. Studies done by the State of Michigan and Grand Valley State University revised initial internal phosphorus load estimates and indicated an imbalance in the phosphorus budget in Bear Lake. From June through November 2015, the U.S. Geological Survey (USGS) did an investigative study to quantify the load of nutrients from shallow groundwater around the Willbrandt Ponds in an effort to update the phosphorus budget to Bear Lake. Seven sampling locations were established, including five shallow groundwater wells and two surface-water sites, in the Willbrandt pond study area and Bear Lake. A total of 12 nutrient samples and discrete water-level measurements were collected from each site from June through November 2015. Continuous water-level data were recorded for both surface-water monitoring locations for the entire sampling period.Water-level data indicated that Willbrandt Pond West had the highest average water-level elevation of all sites monitored, which indicated the general direction of flux is from Willbrandt Pond West to Bear Lake. Nutrient and chloride loading from Willbrandt Pond West to Bear Lake was calculated using two distinct methods: Dupuit and direct seepage methods. Shallow groundwater loading calculations were determined by using groundwater levels to

  20. Modeled sensitivity of Lake Michigan productivity and zooplankton to changing nutrient concentrations and quagga mussels

    Science.gov (United States)

    Pilcher, Darren J.; McKinley, Galen A.; Kralj, James; Bootsma, Harvey A.; Reavie, Euan D.

    2017-08-01

    The recent decline in Lake Michigan productivity is often attributed to filter feeding by invasive quagga mussels, but some studies also implicate reductions in lakewide nutrient concentrations. We use a 3-D coupled hydrodynamic-biogeochemical model to evaluate the effect of changing nutrient concentrations and quagga mussel filtering on phytoplankton production and phytoplankton and zooplankton biomass. Sensitivity experiments are used to assess the net effect of each change separately and in unison. Quagga mussels are found to have the greatest impact during periods of isothermal mixing, while nutrients have the greatest impact during thermal stratification. Quagga mussels also act to enhance spatial heterogeneity, particularly between nearshore-offshore regions. This effect produces a reversal in the gradient of nearshore-offshore productivity: from relatively greater nearshore productivity in the prequagga lake to relatively lesser nearshore productivity after quaggas. The combined impact of both processes drives substantial reductions in phytoplankton and zooplankton biomass, as well as significant modifications to the seasonality of surface water pCO2, particularly in nearshore regions where mussel grazing continues year-round. These results support growing concern that considerable losses of phytoplankton and zooplankton will yield concurrent losses at higher trophic levels. Comparisons to observed productivity suggest that both quagga mussel filtration and lower lakewide total phosphorus are necessary to accurately simulate recent changes in primary productivity in Lake Michigan.

  1. 137Cs radioactive dating of Lake Ontario sediment cores

    International Nuclear Information System (INIS)

    Ward, T.E.; Breeden, J.; Komisarcik, K.; Porter, R.; Czuczwa, J.; Kaminski, R.; McVeety, B.D.

    1987-12-01

    The distribution of 137 Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with 210 Pb dating and distribution of Ambrosia (ragweed) pollen compare well with 137 Cs dating. These methods can determine with precision, changes in sedimentation occurring over the past 100 years or so. Typical sedimentation rates of 0.18-0.36 cm/yr were measured. 16 refs., 3 figs., 2 tabs

  2. Zebra mussels (Dreissena polymorpha) as a biomonitor of trace elements along the southern shoreline of Lake Michigan.

    Science.gov (United States)

    Shoults-Wilson, W Aaron; Elsayed, Norhan; Leckrone, Kristen; Unrine, Jason

    2015-02-01

    The invasive zebra mussel (Dreissena polymorpha) has become an accepted biomonitor organism for trace elements, but it has yet to be studied along the Lake Michigan shoreline. Likewise, the relationships between tissue concentrations of elements, organism size, and sediment concentrations of elements have not been fully explained. The present study found that a variety of allometric variables such as length, dry tissue mass, shell mass, organism condition indices, and shell thickness index were useful in explaining intrasite variability in elemental concentrations. The flesh condition index (grams of tissue dry mass per gram of shell mass) explained variability at the most sites for most elements. Once allometric intrasite variability was taken into account, additional significant differences were found between sites, although the net effect was small. Significant positive relationships between sediment and tissue concentrations were found for Pb and Zn, with a significant negative relationship for Cd. It was also found that Cu and Zn concentrations in tissues increased significantly along the shoreline in the southeasterly direction, whereas Hg increased in a northwesterly direction. Opportunistic sampling found that zebra mussels accumulate significantly higher concentrations of nearly all elements analyzed compared to Asian clams (Corbicula fluminea) at the same site. The present study demonstrates the need to fully explain natural sources of variability before using biomonitors to explain spatial distributions of trace elements. © 2014 SETAC.

  3. Comparing Physics Scheme Performance for a Lake Effect Snowfall Event in Northern Lower Michigan

    Science.gov (United States)

    Molthan, Andrew; Arnott, Justin M.

    2012-01-01

    High resolution forecast models, such as those used to predict severe convective storms, can also be applied to predictions of lake effect snowfall. A high resolution WRF model forecast model is provided to support operations at NWS WFO Gaylord, Michigan, using a 12 ]km and 4 ]km nested configuration. This is comparable to the simulations performed by other NWS WFOs adjacent to the Great Lakes, including offices in the NWS Eastern Region who participate in regional ensemble efforts. Ensemble efforts require diversity in initial conditions and physics configurations to emulate the plausible range of events in order to ascertain the likelihood of different forecast scenarios. In addition to providing probabilistic guidance, individual members can be evaluated to determine whether they appear to be biased in some way, or to better understand how certain physics configurations may impact the resulting forecast. On January 20 ]21, 2011, a lake effect snow event occurred in Northern Lower Michigan, with cooperative observing and CoCoRaHS stations reporting new snow accumulations between 2 and 8 inches and liquid equivalents of 0.1 ]0.25 h. The event of January 21, 2011 was particularly well observed, with numerous surface reports available. It was also well represented by the WRF configuration operated at NWS Gaylord. Given that the default configuration produced a reasonable prediction, it is used here to evaluate the impacts of other physics configurations on the resulting prediction of the primary lake effect band and resulting QPF. Emphasis here is on differences in planetary boundary layer and cloud microphysics parameterizations, given their likely role in determining the evolution of shallow convection and precipitation processes. Results from an ensemble of seven microphysics schemes and three planetary boundary layer schemes are presented to demonstrate variability in forecast evolution, with results used in an attempt to improve the forecasts in the 2011 ]2012

  4. Isotopic fingerprints of anthropogenic molybdenum in lake sediments.

    Science.gov (United States)

    Chappaz, Anthony; Lyons, Timothy W; Gordon, Gwyneth W; Anbar, Ariel D

    2012-10-16

    We measured the molybdenum isotope compositions (δ(98)Mo) of well-dated sediment cores from two lakes in eastern Canada in an effort to distinguish between natural and anthropogenic contributions to these freshwater aquatic systems. Previously, Chappaz et al. (1) ascribed pronounced 20th-century Mo concentration enrichments in these lakes to anthropogenic inputs. δ(98)Mo values in the deeper sediments (reflecting predominantly natural Mo sources) differ dramatically between the two lakes: -0.32 ± 0.17‰ for oxic Lake Tantare and +0.64 ± 0.09‰ for anoxic Lake Vose. Sediment layers previously identified as enriched in anthropogenic Mo, however, reveal significant δ(98)Mo shifts of ± 0.3‰, resulting in isotopically heavier values of +0.05 ± 0.18‰ in Lake Tantare and lighter values of +0.31 ± 0.03‰ in Lake Vose. We argue that anthropogenic Mo modifies the isotopic composition of the recent sediments, and we determine δ(98)Mo(anthropogenic) values of 0.1 ± 0.1‰ (Lake Vose) and 0.2 ± 0.2‰ (Lake Tantare). These calculated inputs are consistent with the δ(98)Mo of molybdenite (MoS(2)) likely delivered to the lakes via smelting of porphyry copper deposits (Lake Vose) or through combustion of coal and oil also containing Mo (Lake Tantare). Our results confirm the utility of Mo isotopes as a promising fingerprint of human impacts and perhaps the specific sources of contamination. Importantly, the magnitudes of the anthropogenic inputs are large enough, relative to the natural Mo cycles in each lake, to have an impact on the microbiological communities.

  5. Avian botulism type E in waterbirds of Lake Michigan, 2010–2013

    Science.gov (United States)

    Chipault, Jennifer G.; White, C. LeAnn; Blehert, David S.; Jennings, Susan K.; Strom, Sean M.

    2015-01-01

    During 2010 to 2013, waterbird mortality surveillance programs used a shared protocol for shoreline walking surveys performed June to November at three areas in northern Lake Michigan. In 2010 and 2012, 1244 total carcasses (0.8 dead bird/km walked) and 2399 total carcasses (1.2 dead birds/km walked), respectively, were detected. Fewer carcasses were detected in 2011 (353 total carcasses, 0.2 dead bird/km walked) and 2013 (451 total carcasses, 0.3 dead bird/km walked). During 3 years, peak detection of carcasses occurred in October and involved primarily migratory diving and fish-eating birds, including long-tailed ducks (Clangula hyemalis; 2010), common loons (Gavia immer; 2012), and red-breasted mergansers (Mergus serrator; 2013). In 2011, peak detection of carcasses occurred in August and consisted primarily of summer residents such as gulls (Larus spp.) and double-crested cormorants (Phalacrocorax auritus). A subset of fresh carcasses was collected throughout each year of the study and tested for botulinum neurotoxin type E (BoNT/E). Sixty-one percent of carcasses (57/94) and 10 of 11 species collected throughout the sampling season tested positive for BoNT/E, suggesting avian botulism type E was a major cause of death for both resident and migratory birds in Lake Michigan. The variety of avian species affected by botulism type E throughout the summer and fall during all 4 years of coordinated surveillance also suggests multiple routes for bird exposure to BoNT/E in Lake Michigan.

  6. A synthesis of the Green Bay (Lake Michigan) mass balance project: Implications for environmental science

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, W.; Endicott, D.; Kreis, R. [Environmental Protection Agency, Grosse Ile, MI (United States). Large Lakes Research Station

    1995-12-31

    The questions confronting environmental managers responsible for the Great Lakes are complex and regulatory action (or inaction) have major social, environmental and economical consequences. It has become evident that rational approaches must be found to address the issues, more clearly identify and quantitate problems, locate and quantitate sources of important chemicals, and arrive at optimal remedial programs. A scientifically based management framework has been implemented and prototyped within the Great Lakes community of mangers and scientists referred to as the Mass Balance Approach. The US Environmental Protection Agency, led by the Great Lakes National Program Office (GLNPO) in cooperation with Office of Research and Development (ORD) and other state and academic organizations, has completed an intensive study of Green Bay (Lake Michigan) to test the feasibility of using the mass balance approach for managing toxic substances in the Great Lakes. This presentation will provide an overview of the project and the results. Conclusions and recommendations will be reviewed and implications for future policy based, scientific studies will be explored.

  7. Occurrence of Escherichia coli and enterococci in Cladophora (Chlorophyta) in nearshore water and beach sand of Lake Michigan.

    Science.gov (United States)

    Whitman, Richard L; Shively, Dawn A; Pawlik, Heather; Nevers, Meredith B; Byappanahalli, Muruleedhara N

    2003-08-01

    Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density of Escherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (+/- standard errors) of 5.3 (+/- 4.8) and 4.8 (+/- 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P Cladophora mats stored at 4 degrees C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches.

  8. Chemical speciation of 239240Pu and 137Cs in Lake Michigan waters

    International Nuclear Information System (INIS)

    Alberts, J.J.; Wahlgren, M.A.; Jehn, P.J.; Nelson, D.M.; Orlandini, K.A.

    1974-01-01

    Studies of the submicron size distribution and charge characteristics of naturally occurring levels of 239 Pu, 240 Pu, and 137 Cs were conducted to help define the physico-chemical state of these fallout derived nuclides in Lake Michigan waters and in precipitation samples taken in the Argonne Laboratory area. Procedures are described for sample collection, size distribution determination, analysis of ion exchange resins, and plutonium determination by evaporation. Results indicated that the radioisotopes exist in several different fractions within the water column and that the total charge of these fractions is different from what would be predicted by simple solution chemistry. The distribution of the isotopes in snow appears to be different from that in the water column, indicating that considerable chemical or physical transformations must take place after the atomospheric input has reached the lake surface

  9. Use of Cs-137 as tracer in lake sediment investigation

    International Nuclear Information System (INIS)

    Dinescu, L.; Vasile, E.; Timofte, L.; Cernisov, G.; Dorcioman, R.

    1997-01-01

    137 Cs vertical profile and total inventories were determined in four lakes located in Danube Delta and surroundings and in channel Dunavat. The radiocaesium total inventory of 1800 Bq/m 2 in Matita and Merhei-Middle Part, very closed to the atmospheric fallout value and a very low sedimentation rate, suggest a relative isolation of these two lakes related to the main Danube branches. The vertical profile obtained in Merhei lake (the Southern part) shows three distinct peaks corresponding to nuclear weapons tests performed in 1954 and 1963 and to Chernobyl event in 1986. Radiocaesium total inventory of 3270 Bq/m 2 was explained by an important 137 Cs contribution from the sediment transported by the channel linking lake Merhei to Dunarea Veche (Chilia branch). For the lakes Leahova and Razim, located in the immediate vicinity of the Black Sea, the total inventories of 600 Bq/m2 suggest an important transfer of sediments from the lakes to Black Sea. 137 Cs vertical profile in Dunavat channel shows two peaks, corresponding to Chernobyl event and nuclear tests. The total inventory of 2600 Bq/m 2 is due to atmospheric fallout and to the sediments transported by the river Danube and then by channel Dunavat. The sedimentation rate of 0.7 cm/year obtained from both peaks, suggests a constant sediment accumulation in the last 33 years. Other environmental tracers were used for recent lake sediment dating. The obtained results (considered as preliminary results) were compared with 137 Cs results. The results obtained from 137 Cs, 210 Pb and 241 Am measurements demonstrated that the environmental tracers are a valuable tool in sediment origin, transport and accumulation investigation. The research is in progress. (authors)

  10. Lake Michigan offshore ecosystem structure and food web changes from 1987 to 2008

    Science.gov (United States)

    Rogers, Mark W.; Bunnell, David B.; Madenjian, Charles P.; Warner, David M.

    2014-01-01

    Ecosystems undergo dynamic changes owing to species invasions, fisheries management decisions, landscape modifications, and nutrient inputs. At Lake Michigan, new invaders (e.g., dreissenid mussels (Dreissena spp.), spiny water flea (Bythotrephes longimanus), round goby (Neogobius melanostomus)) have proliferated and altered energy transfer pathways, while nutrient concentrations and stocking rates to support fisheries have changed. We developed an ecosystem model to describe food web structure in 1987 and ran simulations through 2008 to evaluate changes in biomass of functional groups, predator consumption, and effects of recently invading species. Keystone functional groups from 1987 were identified as Mysis, burbot (Lota lota), phytoplankton, alewife (Alosa pseudoharengus), nonpredatory cladocerans, and Chinook salmon (Oncorhynchus tshawytscha). Simulations predicted biomass reductions across all trophic levels and predicted biomasses fit observed trends for most functional groups. The effects of invasive species (e.g., dreissenid grazing) increased across simulation years, but were difficult to disentangle from other changes (e.g., declining offshore nutrient concentrations). In total, our model effectively represented recent changes to the Lake Michigan ecosystem and provides an ecosystem-based tool for exploring future resource management scenarios.

  11. Heavy metal speciation and their accumulation in sediments of Lake ...

    African Journals Online (AJOL)

    Several sediment samples in Lake Burullus have been affected by the discharges of heavy metals through different drains. The study aimed to analyze the chemical speciation of these metals. In particular, the chemical forms of Cd, Cu, Fe, Mn, Pb and Zn in sediments collected in spring season were studied using a ...

  12. In situ sampling of interstitial water from lake sediments

    NARCIS (Netherlands)

    Brinkman, Albertus G.; van Raaphorst, Wim; Lijklema, Lambertus

    1982-01-01

    A sampler with a relatively high resolution has been developed, which allows interstitial water to be obtained from lake sediments at well defined depths, without serious disturbance of sediment structure. Oxidation effects are excluded. Sampling time is in the order of a day. Installation requires

  13. Incorporation of Fine-Grained Sediment Erodibility Measurements into Sediment Transport Modeling, Capitol Lake, Washington

    Science.gov (United States)

    Stevens, Andrew W.; Gelfenbaum, Guy; Elias, Edwin; Jones, Craig

    2008-01-01

    Capitol Lake was created in 1951 with the construction of a concrete dam and control gate that prevented salt-water intrusion into the newly formed lake and regulated flow of the Deschutes River into southern Puget Sound. Physical processes associated with the former tidally dominated estuary were altered, and the dam structure itself likely caused an increase in retention of sediment flowing into the lake from the Deschutes River. Several efforts to manage sediment accumulation in the lake, including dredging and the construction of sediment traps upriver, failed to stop the lake from filling with sediment. The Deschutes Estuary Feasibility Study (DEFS) was carried out to evaluate the possibility of removing the dam and restoring estuarine processes as an alternative ongoing lake management. An important component of DEFS was the creation of a hydrodynamic and sediment transport model of the restored Deschutes Estuary. Results from model simulations indicated that estuarine processes would be restored under each of four restoration alternatives, and that over time, the restored estuary would have morphological features similar to the predam estuary. The model also predicted that after dam-removal, a large portion of the sediment eroded from the lake bottom would be deposited near the Port of Olympia and a marina located in lower Budd Inlet seaward of the present dam. The volume of sediment transported downstream was a critical piece of information that managers needed to estimate the total cost of the proposed restoration project. However, the ability of the model to predict the magnitude of sediment transport in general and, in particular, the volume of sediment deposition in the port and marina was limited by a lack of information on the erodibility of fine-grained sediments in Capitol Lake. Cores at several sites throughout Capitol Lake were collected between October 31 and November 1, 2007. The erodibility of sediments in the cores was later determined in the

  14. Regional groundwater-flow model of the Lake Michigan Basin in support of Great Lakes Basin water availability and use studies

    Science.gov (United States)

    Feinstein, D.T.; Hunt, R.J.; Reeves, H.W.

    2010-01-01

    A regional groundwater-flow model of the Lake Michigan Basin and surrounding areas has been developed in support of the Great Lakes Basin Pilot project under the U.S. Geological Survey's National Water Availability and Use Program. The transient 2-million-cell model incorporates multiple aquifers and pumping centers that create water-level drawdown that extends into deep saline waters. The 20-layer model simulates the exchange between a dense surface-water network and heterogeneous glacial deposits overlying stratified bedrock of the Wisconsin/Kankakee Arches and Michigan Basin in the Lower and Upper Peninsulas of Michigan; eastern Wisconsin; northern Indiana; and northeastern Illinois. The model is used to quantify changes in the groundwater system in response to pumping and variations in recharge from 1864 to 2005. Model results quantify the sources of water to major pumping centers, illustrate the dynamics of the groundwater system, and yield measures of water availability useful for water-resources management in the region. This report is a complete description of the methods and datasets used to develop the regional model, the underlying conceptual model, and model inputs, including specified values of material properties and the assignment of external and internal boundary conditions. The report also documents the application of the SEAWAT-2000 program for variable-density flow; it details the approach, advanced methods, and results associated with calibration through nonlinear regression using the PEST program; presents the water-level, drawdown, and groundwater flows for various geographic subregions and aquifer systems; and provides analyses of the effects of pumping from shallow and deep wells on sources of water to wells, the migration of groundwater divides, and direct and indirect groundwater discharge to Lake Michigan. The report considers the role of unconfined conditions at the regional scale as well as the influence of salinity on groundwater flow

  15. Sediment deposition and sources into a Mississippi River floodplain lake; Catahoula Lake, Louisiana

    Science.gov (United States)

    Latuso, Karen D.; Keim, Richard F.; King, Sammy L.; Weindorf, David C.; DeLaune, Ronald D.

    2017-01-01

    Floodplain lakes are important wetlands on many lowland floodplains of the world but depressional floodplain lakes are rare in the Mississippi River Alluvial Valley. One of the largest is Catahoula Lake, which has existed with seasonally fluctuating water levels for several thousand years but is now in an increasingly hydrologically altered floodplain. Woody vegetation has been encroaching into the lake bed and the rate of this expansion has increased since major human hydrologic modifications, such as channelization, levee construction, and dredging for improvement of navigation, but it remains unknown what role those modifications may have played in altering lake sedimentation processes. Profiles of thirteen 137Cs sediment cores indicate sedimentation has been about 0.26 cm y− 1 over the past 60 years and has been near this rate since land use changes began about 200 years ago (210Pb, and 14C in Tedford, 2009). Carbon sequestration was low (10.4 g m− 2 y− 1), likely because annual drying promotes mineralization and export. Elemental composition (high Zr and Ti and low Ca and K) and low pH of recent (sediments suggest Gulf Coastal Plain origin, but below the recent sediment deposits, 51% of sediment profiles showed influence of Mississippi River alluvium, rich in base cations such as K+, Ca2 +, and Mg2 +. The recent shift to dominance of Coastal Plain sediments on the lake-bed surface suggests hydrologic modification has disconnected the lake from sediment-bearing flows from the Mississippi River. Compared to its condition prior to hydrologic alterations that intensified in the 1930s, Catahoula Lake is about 15 cm shallower and surficial sediments are more acidic. Although these results are not sufficient to attribute ecological changes directly to sedimentological changes, it is likely the altered sedimentary and hydrologic environment is contributing to the increased dominance of woody vegetation.

  16. Age determination of bottom sediments from Lake Hovsgol, Mongolia

    International Nuclear Information System (INIS)

    Ito, Kazumi; Nakamura, Toshio; Duller, Geoff; Hasebe, Noriko; Kashiwaya, Kenji

    2013-01-01

    Dating plays a key role in determining past environmental changes in lake sediments cores. The feldspar post-IR infrared stimulated luminescence (IRSL) procedure is one of the IRSL procedures and has a great potential to date older samples compared to quartz optically stimulated luminescence (OSL). In this study, the post-IR IRSL (pIRIR) procedure was applied to the polymineral fine grained sediments from Lake Khuvsgul (Hovsgol), Mongolia, and these ages were compared to 14 C ages of bulk samples from the certain depths. The pIRIR ages are always younger than 14 C ages from bulk samples, however, it was possible to construct the suitable age model based on luminescence and 14 C ages. Therefore, pIRIR 225 protocol can be contributed to estimate the sedimentation age of lake sediments as well as 14 C dating. (author)

  17. Contemporary and historical trace metal loadings to the sediments of four lakes of the Lake Washington drainage. Completion report

    International Nuclear Information System (INIS)

    Spyridakis, D.E.; Barnes, R.S.

    1978-01-01

    Contemporary and historical loadings of lead, zinc, and copper to the profundal sediments of Lakes Washington, Sammamish, Chester Morse, and Findley were determined using chemical analysis and 210 Pb dating of sediment cores. Elemental sedimentation rates, a cross product of the sedimentation rate, and sediment concentration of a given element, were corrected for natural background concentrations and rates, and extrapolated across established sediment accumulating areas to give a conservative estimate of the pollutional trace metal loadings to each lake. The resulting chronological loadings appeared consistent with the known cultural history of the individual watersheds. Substantial alterations in sedimentation rates were noted in all lakes where deforestation, road building, suburbanization or urbanization had occurred in the lake's watershed. The quantities, elemental ratios and pollutional histories of copper, lead and zinc in the lake sediments indicate that aeolian inputs are the dominant source of trace metal pollution to the lake sediments at the present time

  18. Optimal control of suspended sediment distribution model of Talaga lake

    Science.gov (United States)

    Ratianingsih, R.; Resnawati, Azim, Mardlijah, Widodo, B.

    2017-08-01

    Talaga Lake is one of several lakes in Central Sulawesi that potentially to be managed in multi purposes scheme because of its characteristic. The scheme is addressed not only due to the lake maintenance because of its sediment but also due to the Algae farming for its biodiesel fuel. This paper governs a suspended sediment distribution model of Talaga lake. The model is derived from the two dimensional hydrodynamic shallow water equations of the mass and momentum conservation law of sediment transport. An order reduction of the model gives six equations of hyperbolic systems of the depth, two dimension directional velocities and sediment concentration while the bed elevation as the second order of turbulent diffusion and dispersion are neglected. The system is discreted and linearized such that could be solved numerically by box-Keller method for some initial and boundary condition. The solutions shows that the downstream velocity is play a role in transversal direction of stream function flow. The downstream accumulated sediment indicate that the suspended sediment and its changing should be controlled by optimizing the downstream velocity and transversal suspended sediment changing due to the ideal algae growth need.

  19. 75 FR 78928 - Limited Service Domestic Voyage Load Lines for River Barges on Lake Michigan, Delay of Effective...

    Science.gov (United States)

    2010-12-17

    ...-AA17 Limited Service Domestic Voyage Load Lines for River Barges on Lake Michigan, Delay of Effective Date AGENCY: Coast Guard, DHS. ACTION: Notice of delay of effective date and reopening of the comment... 46 CFR part 45 as amended by the final rule published in the November 18, 2010, Federal Register (75...

  20. 33 CFR 165.904 - Lake Michigan at Chicago Harbor & Burnham Park Harbor-Safety and Security Zone.

    Science.gov (United States)

    2010-07-01

    ... & Burnham Park Harbor-Safety and Security Zone. 165.904 Section 165.904 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION... Guard District § 165.904 Lake Michigan at Chicago Harbor & Burnham Park Harbor—Safety and Security Zone...

  1. 76 FR 30072 - Safety Zones; Annual Events Requiring Safety Zones in the Captain of the Port Lake Michigan Zone

    Science.gov (United States)

    2011-05-24

    ...). (2) Enforcement date and time. The Sunday before Memorial Day; 8:30 p.m. to 10 p.m. (f) Michigan.... to 11 p.m. (i) Harborfest Music and Family Festival; Racine, WI. (1) Location. All waters of Lake...

  2. Atmospheric Mercury Transport Across Southern Lake Michigan: Influence from the Chicago/Gary Urban Area

    Science.gov (United States)

    Gratz, L. E.; Keeler, G. J.; Dvonch, J. T.

    2008-12-01

    The local and regional impacts of mercury emissions from major urban and industrial areas are critical to quantify in order to further understand mercury cycling in the environment. The Chicago/Gary urban area is one such location in which mercury emissions from industrial sources are significant and regional mercury transport needs to be further examined. Speciated atmospheric mercury was measured in Chicago, IL and Holland, MI from July to November 2007 to better characterize the impact of Chicago/Gary on southwest Michigan. Previous work under the 1994-1995 Lake Michigan Mass Balance Study (LMMBS) indicated that the highest levels of mercury deposition in southwest Michigan occurred with transport from the Chicago/Gary area, particularly with rapid transport where less mercury was deposited close to sources(1). However, at that time it was not possible to measure reactive gas phase mercury (RGM), a highly-soluble form of mercury in industrial emissions that is readily removed from the atmosphere. Since the LMMBS, the development of speciated mercury systems has made it possible to continuously monitor gaseous elemental mercury (Hg0), particulate mercury (HgP), and RGM. These measurements are useful for understanding atmospheric mercury chemistry and differentiating between local and regional source impacts due to the different behaviors of reactive and elemental mercury. Results from 2007 show that, on average, Hg0 and HgP were 1.5 times higher and RGM was 2 times higher in Chicago than in Holland. Mean mercury wet deposition was nearly 3 times higher in Chicago than in Holland. Meteorological analysis indicates that transport across the lake from Chicago/Gary occurred frequently during the study. Additional measurements of O3, SO2, meteorological parameters, event mercury and trace element precipitation samples, and modeled back-trajectories are used to discern regional transport events from local deposition and characterize the impact of the Chicago/Gary urban

  3. Spatial and temporal analysis of lake sedimentation under reforestation

    Directory of Open Access Journals (Sweden)

    C.M. Pilgrim

    2015-10-01

    Full Text Available Spatial and temporal land cover changes can reduce or accelerate lake sedimentation. This study was conducted to examine morphometry and bathymetry, and the long-term changes (over 75 years in sedimentation in the Lake Issaqueena reservoir, South Carolina. The watershed and catchment areas were delineated using Light Detection and Ranging (LiDAR based data. Trends in lake surface area and riparian buffer condition (vegetated or unvegetated were determined from historical aerial photography. From 1938 to 2009, the lake experienced a decrease in surface area of approximately 11.33 ha while catchment area increased by 6.99 ha, and lake volume decreased by 320,800.00 m3. Lake surface area decreased in years corresponding to equal coverage or largely unvegetated riparian buffers. Surface area and average annual precipitation were not correlated; therefore other factors such as soil type, riparian buffer condition and changes in land use likely contributed to sedimentation. Shift from agricultural land to forestland in this watershed resulted in a decrease in sedimentation rates by 88.28%. Keywords: Bathymetry, Erosion, Geographic Information Systems (GIS, Land cover, Riparian buffer, Soils

  4. Early steroid sulfurisation in surface sediments of a permanebtly stratified lake (Ace Lake, Antarctica)

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Rijpstra, W.I.C.; Robertson, L.; Volkman, J.K.

    2000-01-01

    Surface sediments (0 25 cm) from Ace Lake (eastern Antarctica), a saline euxinic lake, were analyzed to study the early incorporation of reduced inorganic sulfur species into organic matter. The apolar fractions were shown to consist predominantly of dimeric (poly)sulfide linked C27-C29 steroids.

  5. Climatic changes inferred fron analyses of lake-sediment cores, Walker Lake, Nevada

    International Nuclear Information System (INIS)

    Yang, In Che.

    1989-01-01

    Organic and inorganic fractions of sediment collected from the bottom of Walker Lake, Nevada, have been dated by carbon-14 techniques. Sedimentation rates and the organic-carbon content of the sediment were correlated with climatic change. The cold climate between 25,000 and 21,000 years ago caused little runoff, snow accumulation on the mountains, and rapid substantial glacial advances; this period of cold climate resulted in a slow sedimentation rate (0.20 millimeter per year) and in a small organic-carbon content in the sediment. Also, organic-carbon accumulation rates in the lake during this period were slow. The most recent period of slow sedimentation rate and small organic-carbon content occurred between 10,000 and 5500 years ago, indicative of low lake stage and dry climatic conditions. This period of dry climate also was evidenced by dry conditions for Lake Lahontan in Nevada and Searles Lake in California, as cited in the literature. Walker Lake filled rapidly with water between 5500 and 4500 years ago. The data published in this report was not produced under an approved Site Investigation Plan (SIP) or Study Plan (SP) and will not be used in the licensing process. 10 refs., 3 figs., 2 tabs

  6. Evaluating the negative effect of benthic egg predators on bloater recruitment in northern Lake Michigan

    Science.gov (United States)

    Bunnell, David B.; Mychek-Londer, Justin G.; Diana, James S.; Stott, Wendylee; Madenjian, Charles P.

    2012-01-01

    As the only extant deepwater cisco in Lake Michigan, bloater is currently at record low levels of abundance.  Several mechanisms to regulate their recruitment have been proposed, including skewed sex ratios, predation on their larvae by adult alewife, and climatic factors during early life history stages, but none has unequivocal support.  In this research, we evaluated an alternative mechanism of egg predation that was supported by an inverse relationship between bloater recruitment and biomass of slimy sculpin, which are known to be effective egg predators.  To that end, we used a combination of field sampling, laboratory experiments, and modeling to estimate the proportion of bloater eggs consumed by sculpins each year between 1973 and 2008.  Monthly field sampling between January through May 2009-2010 (when bloater eggs were incubating) offshore of Frankfort (Michigan), Sturgeon Bay (Wisconsin), Two Rivers (Wisconsin), and Muskegon (Michigan) provided benthivore diets for subsequent laboratory processing.  Identification and enumeration of stomach contents and subsequent genetic analyses of eggs revealed that the mean proportion of bloater eggs in slimy sculpin diets (N = 1016) equaled 0.04.  Bloater eggs also were consumed by deepwater sculpins (N = 699) at a slightly lower mean proportion (0.02), and only one round goby diet among 552 enumerated revealed a bloater egg.  Based on the diet results, we developed daily ration models to estimate consumption for both deepwater and slimy sculpins.  We conducted feeding experiments to estimate gastric evacuation (GEVAC) for water temperatures ranging 2-5 °C, similar to those observed during egg incubation.  GEVAC rates equaled 0.0115/ h for slimy sculpin and 0.0147/h for deepwater sculpin, and did not vary between 2.7 and 5.1 °C for either species or between prey types (Mysis relicta and fish eggs) for slimy sculpin.  Index of fullness [(g prey/g fish weight)100%] was estimated from sculpins sampled in

  7. Modern processes of sediment formation in Lake Towuti, Indonesia, as derived from the composition of lake surface sediments

    Science.gov (United States)

    Hasberg, Ascelina; Melles, Martin; Morlock, Marina; Vogel, Hendrik; Russel, James M.; Bijaksana, Satria

    2016-04-01

    In summer 2015, a drilling operation funded by the International Continental Scientific Drilling Program (ICDP) was conducted at Lake Towuti (2.75°S, 121.5°E), the largest tectonically formed lake (surface area: 561 km²) of the Republic Indonesia. The Towuti Drilling Project (TDP) recovered more than 1000 meters of sediment core from three sites. At all three sites replicate cores down to 133, 154, and 174 m below lake floor have penetrated the entire lake sediment record, which is expected to comprise the past ca. 650.000 years continuously. Lake Towutís sediment record thus can provide unique information for instance concerning the climatic and environmental history in the Indo-Pacific-Warm-Pool (IPWP) and concerning the evolutionary biology in SE Asia. For a better understanding of the palaeoenvironmental proxies to be analyzed on the drill cores, the modern processes of sediment formation in the lake and in its catchment - under known environmental conditions - were investigated on a set of 84 lake sediment surface samples. Sampling was conducted by grab sampler (UWITEC Corp., Austria) in a grid of 1 to 4 km resolution that covers the entire lake. The samples were analyzed for inorganic geochemical composition (XRF powder scans and ICP-MS), magnetic susceptibility (Kappabridge), grain-size distribution (laser scanner), biogenic components (smear-slide analyses), biogenic silica contents (leaching), and carbonate, total organic carbon (TOC), nitrogen (TN), and sulfur (TS) concentrations (elemental analyzer). The sediments close to the lake shores and in front of the major river inlets are characterized by mean grain sizes coarser than average and high magnetic susceptibilities presented by high ratios of Cr, Ni, Co, and Zr. This reflects higher energies due to wave action and fluvial sediment supply, as well as the occurrence of magnetic minerals particularly in the sand and gravel fractions of the sediments. In regions of deeper waters and more distal to

  8. Age and growth of the kiyi, Leucichthys kiyi Koelz, in Lake Michigan

    Science.gov (United States)

    Deason, Hilary J.; Hile, Ralph

    1947-01-01

    Ages were determined and individual growth histories were calculated from the examination and measurement of the scales of 1,649 kiyis captured at seven localities in Lake Michigan in 1931 and 1932. The numbers of individuals employed for the investigation of other phases of the life history (such as length-frequency distributions, length-weight relationship, and sex ratio) varied according to the amount of data available or required. Age-group IV was dominant in the 1931 collections from Racine, Port Washington, and Kewaunee, Wisconsin, and age-group V dominated the 1932 samples from the Fox Islands and from three localities southward of Manistique, Michigan. A trend was noticeable toward an increase in average age from south to north. Among the explanations suggested for the observed differences in age composition were: Variation with latitude in the natural span of life; differences in fishing intensity; fluctuations in the strength of year classes (to account possibly for the shift in the dominant age group from 1931 to 1932). The oldest male kiyi belonged to the VII group and the oldest female was a member of the X group. The possible distorting effects of such factors as gear selection traceable to differences in the mesh sizes of nets fished in 1931 and 1932, selection by nets on the basis of the condition (K) of the fish, and local variations in fishing intensity and hence in the selective destruction of rapidly growing individuals in the fishery were held to be sufficiently great to render doubtful the significance of most of the observed local differences in growth rate. Kiyis from all samples were combined to determine the general growth in length. The growth in weight of the Fox Islands fish, however, was considered separately as these fish were consistently lighter than kiyis of corresponding length from other localities. The Lake Michigan kiyi grows slowly, with the females growing slightly more rapidly than the males. The grand average calculated

  9. An integrated assessment for wind energy in Lake Michigan coastal counties.

    Science.gov (United States)

    Nordman, Erik; VanderMolen, Jon; Gajewski, Betty; Isely, Paul; Fan, Yue; Koches, John; Damm, Sara; Ferguson, Aaron; Schoolmaster, Claire

    2015-04-01

    The benefits and challenges of onshore and offshore wind energy development were assessed for a 4-county area of coastal Michigan. Economic, social, environmental, and spatial dimensions were considered. The coastal counties have suitable wind resources for energy development, which could contribute toward Michigan's 10% renewable energy standard. Wind energy is cost-effective with contract prices less than the benchmark energy price of a new coal-fired power plant. Constructing a 100 MW wind farm could have a $54.7 million economic impact. A patchwork of township-level zoning ordinances regulates wind energy siting. Voluntary collaborations among adjacent townships standardizing the ordinances could reduce regulatory complexity. A Delphi Inquiry on offshore wind energy in Lake Michigan elicited considerable agreement on its challenges, but little agreement on the benefits to coastal communities. Offshore turbines could be acceptable to the participants if they reduced pollution, benefited coastal communities, involved substantial public participation, and had minimal impact on property values and tourism. The US Coast Guard will take a risk-based approach to evaluating individual offshore developments and has no plans to issue blanket restrictions around the wind farms. Models showed that using wind energy to reach the remainder of the 10% renewable energy standard could reduce SO2 , NOx , and CO2 pollution by 4% to 7%. Turbines are highly likely to impact the area's navigational and defense radar systems but planning and technological upgrades can reduce the impact. The integrated assessment shows that responsible wind energy development can enhance the quality of life by reducing air pollution and associated health problems and enhancing economic development. Policies could reduce the negative impacts to local communities while preserving the benefits to the broader region. © 2015 SETAC.

  10. Cesium-137 activities in fish residing in thermal discharges to Lake Michigan

    International Nuclear Information System (INIS)

    Spigarelli, S.A.

    1976-01-01

    The results of a study of 137 Cs activity in brown and rainbow trout and chinook salmon found in the thermal discharges from power plant sites on Lake Michigan, are reported. The objectives of the investigation were: (1) to compare 137 Cs activities in plume 'resident' fish with those in fish collected from reference (unheated) areas; (2) to compare the residence effect on the three sport fishes; and (3) to evaluate the radioecological significance of thermal discharge residence on temporal trends in 137 Cs accumulation by these fishes. Plume resident fish were identified and the residence time of these individuals estimated by the use of temperature-sensitive fish tags. Results are shown tabulated. (U.K.)

  11. The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan

    Science.gov (United States)

    Heuvel, A.V.; McDermott, C.; Pillsbury, R.; Sandrin, T.; Kinzelman, J.; Ferguson, J.; Sadowsky, M.; Byappanahalli, M.; Whitman, R.; Kleinheinz, G.T.

    2010-01-01

    A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. Th is study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations in water underlying mats were significantly greater than surrounding water (p bacterial pathogens, however, could not be detected by microbiological culture methods either attached to mat biomass or in underlying water. Removal of Cladophora mats from beach areas may improve aesthetic and microbial water quality at affected beaches. These associations and potential natural growth of E. coli in bathing waters call into question the efficacy of using E. coli as a recreational water quality indicator of fecal contaminations. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  12. The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan.

    Science.gov (United States)

    Vanden Heuvel, Amy; McDermott, Colleen; Pillsbury, Robert; Sandrin, Todd; Kinzelman, Julie; Ferguson, John; Sadowsky, Michael; Byappanahalli, Muruleedhara; Whitman, Richard; Kleinheinz, Gregory T

    2010-01-01

    A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. This study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations in water underlying mats were significantly greater than surrounding water (p Cladophora mats had lower E. coli concentrations, but surpassed EPA swimming criteria the majority of sampling days. A significant positive association was found between E. coli concentrations attached to Cladophora and in underlying water (p Cladophora mats from beach areas may improve aesthetic and microbial water quality at affected beaches. These associations and potential natural growth of E. coli in bathing waters call into question the efficacy of using E. coli as a recreational water quality indicator of fecal contaminations.

  13. Cesium-137 activities in fish residing in thermal discharges to Lake Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Spigarelli, S A [Argonne National Lab., Ill. (USA)

    1976-05-01

    The results of a study of /sup 137/Cs activity in brown and rainbow trout and chinook salmon found in the thermal discharges from power plant sites on Lake Michigan, are reported. The objectives of the investigation were: (1) to compare /sup 137/Cs activities in plume 'resident' fish with those in fish collected from reference (unheated) areas; (2) to compare the residence effect on the three sport fishes; and (3) to evaluate the radioecological significance of thermal discharge residence on temporal trends in /sup 137/Cs accumulation by these fishes. Plume resident fish were identified and the residence time of these individuals estimated by the use of temperature-sensitive fish tags. Results are shown tabulated.

  14. Vertical distribution of 137Cs in lake sediments in post-Chernobyl period

    International Nuclear Information System (INIS)

    Gorgun, T.V.; Putyrskaya, V.V.; Klemt, E.; Goncharova, N.V.

    2011-01-01

    The vertical distribution of 137 Cs was studied in one of the glacial lakes situated in the region of Tuchola Forest National Park (Poland). Radiocaesium was used for sedimentation rates estimation and dating of the sediment layers of the lake.

  15. Influence of Cladophora-Quagga Mussel Assemblages on Nearshore Methylmercury Production in Lake Michigan.

    Science.gov (United States)

    Lepak, Ryan F; Krabbenhoft, David P; Ogorek, Jacob M; Tate, Michael T; Bootsma, Harvey A; Hurley, James P

    2015-07-07

    Recent spread of invasive mussels in Lake Michigan has altered primary productivity in the nearshore zone, resulting in proliferation of filamentous benthic green algae (Cladophora glomerata). In areas of dense Cladophora and quagga mussel (Dreissena bugensis) assemblages, as well as in regions where sloughed Cladophora accumulates, methylmercury (MeHg) production is enhanced. A shoreline transect from a river mouth through waters overlying Cladophora/quagga-rich zones showed that aqueous MeHg concentrations increased, despite river dilution. Cladophora, as primary producers, ranged from 0.6 to 7.5 ng g(-1) MeHg [4-47% of total mercury (Hg) as MeHg], and were higher than MeHg concentrations in offshore-collected seston. Concentrations of MeHg in decaying Cladophora accumulated onshore ranged from 2.6 to 18.0 ng g(-1) MeHg (18-41% as MeHg) and from 0.1 to 3.0 ng g(-1) MeHg (2-21% as MeHg) in deposits of recently sloughed and accumulated Cladophora in a nearshore topographical depression. Relative to offshore open waters, interstitial waters within decaying Cladophora from onshore and nearshore deposits were elevated in MeHg concentration, 1000- and 10-fold, respectively. Percent Hg as MeHg was also elevated (65-75% and 9-19%, respectively for onshore interstitial water and nearshore interstitial water, compared to 0.2-3.3% as MeHg for open water). Quagga mussels collected within growing Cladophora beds in the nearshore zone were significantly higher in MeHg than offshore counterparts. Our combined results suggest that recent changes in nearshore primary production contributes to MeHg production and bioaccumulation in Lake Michigan.

  16. Cladophora (Chlorophyta) spp. harbor human bacterial pathogens in nearshore water of Lake Michigan

    Science.gov (United States)

    Ishii, S.; Yan, T.; Shively, D.A.; Byappanahalli, M.N.; Whitman, R.L.; Sadowsky, M.J.

    2006-01-01

    Cladophora glomerata, a macrophytic green alga, is commonly found in the Great Lakes, and significant accumulations occur along shorelines during the summer months. Recently, Cladophora has been shown to harbor high densities of the fecal indicator bacteria Escherichia coli and enterococci. Cladophora may also harbor human pathogens; however, until now, no studies to address this question have been performed. In the present study, we determined whether attachedCladophora, obtained from the Lake Michigan and Burns Ditch (Little Calumet River, Indiana) sides of a breakwater during the summers of 2004 and 2005, harbored the bacterial pathogens Shiga toxin-producing Escherichia coli (STEC),Salmonella, Shigella, and Campylobacter. The presence of potential pathogens and numbers of organisms were determined by using cultural methods and by using conventional PCR, most-probable-number PCR (MPN-PCR), and quantitative PCR (QPCR) performed with genus- and toxin-specific primers and probes. WhileShigella and STEC were detected in 100% and 25%, respectively, of the algal samples obtained near Burns Ditch in 2004, the same pathogens were not detected in samples collected in 2005. MPN-PCR and QPCR allowed enumeration of Salmonella in 40 to 80% of the ditch- and lakeside samples, respectively, and the densities were up to 1.6 × 103 cells per g Cladophora. Similarly, these PCR methods allowed enumeration of up to 5.4 × 102 Campylobacter cells/gCladophora in 60 to 100% of lake- and ditchside samples. The Campylobacterdensities were significantly higher (P fingerprint analyses indicated that genotypically identical Salmonella isolates were associated with geographically and temporally distinct Cladophora samples. However, Campylobacter isolates were genetically diverse. Since animal hosts are thought to be the primary habitat forCampylobacter and Salmonella species, our results suggest that Cladophora is a likely secondary habitat for pathogenic

  17. Cladophora (Chlorophyta) spp. harbor human bacterial pathogens in nearshore water of Lake Michigan.

    Science.gov (United States)

    Ishii, Satoshi; Yan, Tao; Shively, Dawn A; Byappanahalli, Muruleedhara N; Whitman, Richard L; Sadowsky, Michael J

    2006-07-01

    Cladophora glomerata, a macrophytic green alga, is commonly found in the Great Lakes, and significant accumulations occur along shorelines during the summer months. Recently, Cladophora has been shown to harbor high densities of the fecal indicator bacteria Escherichia coli and enterococci. Cladophora may also harbor human pathogens; however, until now, no studies to address this question have been performed. In the present study, we determined whether attached Cladophora, obtained from the Lake Michigan and Burns Ditch (Little Calumet River, Indiana) sides of a breakwater during the summers of 2004 and 2005, harbored the bacterial pathogens Shiga toxin-producing Escherichia coli (STEC), Salmonella, Shigella, and Campylobacter. The presence of potential pathogens and numbers of organisms were determined by using cultural methods and by using conventional PCR, most-probable-number PCR (MPN-PCR), and quantitative PCR (QPCR) performed with genus- and toxin-specific primers and probes. While Shigella and STEC were detected in 100% and 25%, respectively, of the algal samples obtained near Burns Ditch in 2004, the same pathogens were not detected in samples collected in 2005. MPN-PCR and QPCR allowed enumeration of Salmonella in 40 to 80% of the ditch- and lakeside samples, respectively, and the densities were up to 1.6 x 10(3) cells per g Cladophora. Similarly, these PCR methods allowed enumeration of up to 5.4 x 10(2) Campylobacter cells/g Cladophora in 60 to 100% of lake- and ditchside samples. The Campylobacter densities were significantly higher (P Cladophora samples than in the ditchside Cladophora samples. DNA fingerprint analyses indicated that genotypically identical Salmonella isolates were associated with geographically and temporally distinct Cladophora samples. However, Campylobacter isolates were genetically diverse. Since animal hosts are thought to be the primary habitat for Campylobacter and Salmonella species, our results suggest that Cladophora is a

  18. Geochemical Anomalies in the Sediments of Lake Druksiai

    International Nuclear Information System (INIS)

    Kleinas, A.

    1999-01-01

    In order to evaluate the impact of Ignalina Nuclear Power Plant (NPP) on natural processes in Lake Druksiai and accumulation of pollutants, in 19931997, carrying on the state scientific program, the Marine Geochemistry Division of the Institute of Geography performed lithological geochemical mapping of lake bottom sediments on a scale of 1 .50 000. The results obtained enabled to distinguish zones of higher anthropogenous geochemical load, where geochemical anomalies of pollutants, including oil hydrocarbons and heavy metals, had been taken into account. Applying concentration coefficients for oil hydrocarbons and heavy metals (Cr, Cu, Ni, Pb, and Zn) and their natural background, the attempt was made to differentiate natural and technogenous components in the geochemical anomalies As expected, the finer sediments -aleurite-pelite mud - showed amounts of oil hydrocarbons and heavy metals being 12.1 times higher than in fine sand - the most coarse of the sediments studied Sediments with organic mater exceeding 20% contained 11.7 times more pollutants than those with organic matter below 1 .5%. Calculations of concentration coefficients (CC) showed no elements in no stations exceeded 10 - the sediments did not reach the category of high pollution However, in many sites, the coefficients exceeded values of 1-2, thus, showing sediments attributable to the categories of weakly polluted or just polluted. Mapping model done by GIS methods (by superimposing schemes of pollutant CCs distribution in the lake and summing them) for geochemical anomalies two derivative map-schemes were obtained for oil hydrocarbons and heavy metals. They showed that clean sediments cover just 24.75% (according to the pollutant background for soil types) and 12.35% (according to the organic matter background for its amount intervals) lake bottom area. Zones slightly polluted by an element at least cover 69.7 and 80.29% of lake area, correspondingly; whereas zones slightly polluted by all

  19. Monitoring climate signal transfer into the varved lake sediments of Lake Czechowskie, Poland

    Science.gov (United States)

    Groß-Schmölders, Miriam; Ott, Florian; Brykała, Dariusz; Gierszewski, Piotr; Kaszubski, Michał; Kienel, Ulrike; Brauer, Achim

    2015-04-01

    In 2012 we started a monitoring program at Lake Czechowskie, Poland, because the lake comprises a long Holocene time series of calcite varves until recent times. The aim of the program is to understand how environmental and climatic conditions influence the hydrological conditions and, ultimately, the sediment deposition processes of the lake. Lake Czechowskie is located in the north of Poland in the Pomeranian Lake District and is part of the national park Tuchola Forest. The landscape and the lake is formed by the glacier retreat after the last glaciation (Weichselian). Lake Czechowskie is a typical hardwater lake and has a length of 1.4 km, an average width of 600 m and a lake surface area of ca 4 km. The maximum depth of 32 m is reached in a rather small hollow in the eastern part of the lake. Two different types of sediment traps provide sediment samples with monthly resolution from different water depths (12m, 26m). In addition, hydrological data including water temperature in different depths, water inflow, throughflow and outflow and the depth of visibility are measured. These data allow to describe strength and duration of lake mixing in spring and autumn and its influence on sedimentation. The sediment samples were analyzed with respect to their dry weight (used to calculate mean daily sediment flux), their inorganic and organic carbon contents, the stable C- and O-isotopes of organic matter and calcite as well as N-isotopes of organic matter. For selected samples dominant diatom taxa are determined. Our first results demonstrate the strong influence of the long winter with ice cover until April in 2013 on the sedimentation. A rapid warming in only 9 days starting on April 9th from -0,3 C° to 15,2 C° resulted in fast ice break-up and a short but intensive lake mixing. In consequence of this short mixing period a strong algal bloom especially of Fragilaria and Crysophycea commenced in April and had its maximum in May. This bloom further induced biogenic

  20. Excess unsupported sup(210)Pb in lake sediment from Rocky Mountain lakes

    International Nuclear Information System (INIS)

    Norton, S.A.; Hess, C.T.; Blake, G.M.; Morrison, M.L.; Baron, J.

    1985-01-01

    Sediment cores from four high-altitude (approximately 3200 m) lakes in Rocky Mountain National Park, Colorado, were dated by sup(210)Pb chronology. Background (supported) sup(210)Pb activities for the four cores range from 0.26 to 0.93 Beq/g dry weight, high for typical oligotrophic lakes. Integrated unsupported sup(210)Pb ranges from 0.81 (a typical value for most lakes) to 11.0 Beq/cmsup(2). The sup(210)Pb activity in the surface sediments ranges from 1.48 to 22.2 Beq/g dry weight. Sedimentation from Lake Louise, the most unusual of the four, has 22.2 Beq/g dry weight at the sediment surface, an integrated unsupported sup(210)Pb=11.0 Beq/cmsup(2), and supported sup(210)Pb=0.74 Beq/g dry weight. sup(226)Ra content of the sediment is insufficient to explain either the high unsupported sup(210)Pb or the sup(222)Rn content of the water column of Lake Louise, which averaged 96.2 Beq/L. We concluded that sup(222)Rn-rich groundwater entering the lake is the source of the high sup(222)Rn in the water column. This, in turn, is capable of supporting the unusually high sup(210)Pb flux to the sediment surface. Groundwater with high sup(222)Rn may control the sup(210)Pb budget of lakes where sediment cores have integrated unsupported sup(210)Pb greater than 2 Beq/cmsup(2)

  1. Occurrence of Escherichia coli and enterococci in Cladophora (Clorophyta) in nearshore water and beach sand of Lake Michigan

    Science.gov (United States)

    Whitman, Richard L.; Shively, Dawn A.; Pawlik, Heather; Nevers, Meredith B.; Byappanahalli, Muruleedhara N.

    2003-01-01

    Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density of Escherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (± standard errors) of 5.3 (± 4.8) and 4.8 (± 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P R2 = 0.73, n = 17) but not in northern beaches (P = 0.892, n = 16). Both E. coli and enterococci survived for over 6 months in sun-dried Cladophora mats stored at 4°C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches.

  2. Fine sediment erodibility in Lake Okeechobee, Florida

    OpenAIRE

    Mehta, Ashish J.; Hwang, Kyu-Nam

    1989-01-01

    The critical need to predict the turbidity in water due to fine-grained sediment suspension under wave action over mud deposits for sedimentation and erosion studies, as well as sorbed contaminant transport, is well known. Since fall velocities of fine sediment particles are very small, they can be easily transported by hydrodynamic flows such as waves and currents. The presence of these particles in the water column affects accoustic transmission, heat absorption and depth of ...

  3. Spatially explicit measures of production of young alewives in Lake Michigan: Linkage between essential fish habitat and recruitment

    Science.gov (United States)

    Hook, Tomas O.; Rutherford, Edward S.; Brines, Shannon J.; Mason, Doran M.; Schwab, David J.; McCormick, Michael; Desorcie, Timothy J.

    2003-01-01

    The identification and protection of essential habitats for early life stages of fishes are necessary to sustain fish stocks. Essential fish habitat for early life stages may be defined as areas where fish densities, growth, survival, or production rates are relatively high. To identify critical habitats for young-of-year (YOY) alewives (Alosa pseud oharengus) in Lake Michigan, we integrated bioenergetics models with GIS (Geographic Information Systems) to generate spatially explicit estimates of potential population production (an index of habitat quality). These estimates were based upon YOY alewife bioenergetic growth rate potential and their salmonine predators’ consumptive demand. We compared estimates of potential population production to YOY alewife yield (an index of habitat importance). Our analysis suggested that during 1994–1995, YOY alewife habitat quality and yield varied widely throughout Lake Michigan. Spatial patterns of alewife yield were not significantly correlated to habitat quality. Various mechanisms (e.g., predator migrations, lake circulation patterns, alternative strategies) may preclude YOY alewives from concentrating in areas of high habitat quality in Lake Michigan.

  4. Lake Michigan Diversion Accounting land cover change estimation by use of the National Land Cover Dataset and raingage network partitioning analysis

    Science.gov (United States)

    Sharpe, Jennifer B.; Soong, David T.

    2015-01-01

    The U.S. Army Corps of Engineers (USACE), Chicago District, is responsible for monitoring and computation of the quantity of Lake Michigan water diverted by the State of Illinois. As part of this effort, the USACE uses the Hydrological Simulation Program–FORTRAN (HSPF) with measured meteorological data inputs to estimate runoff from the Lake Michigan diversion special contributing areas (SCAs), the North Branch Chicago River above Niles and the Little Calumet River above South Holland gaged basins, and the Lower Des Plaines and the Calumet ungaged that historically drained to Lake Michigan. These simulated runoffs are used for estimating the total runoff component from the diverted Lake Michigan watershed, which is accountable to the total diversion by the State of Illinois. The runoff is simulated from three interpreted land cover types in the HSPF models: impervious, grass, and forest. The three land cover data types currently in use were derived from aerial photographs acquired in the early 1990s.

  5. Circulation and sedimentation in a tidal-influenced fjord lake: Lake McKerrow, New Zealand

    Science.gov (United States)

    Pickrill, R. A.; Irwin, J.; Shakespeare, B. S.

    1981-01-01

    Lake McKerrow is a tide-influenced fjord lake, separated from the open sea by a Holocene barrier spit. Fresh, oxygenated waters of the epilimnion overlie saline, deoxygenated waters of the hypolimnion. During winter, water from the Upper Hollyford River interflows along the pycnocline, depositing coarse silt on the steep delta and transporting finer sediment down-lake. An extensive sub-lacustrine channel system on the foreset delta slope is possibly maintained by turbidity currents. Saline waters of the hypolimnion are periodically replenished. During high tides and low lake levels saline water flows into the lake and downslope into the lake basin as a density current in a well defined channel.

  6. Effects of dressing and cooking on DDT concentrations in certain fish from Lake Michigan

    Science.gov (United States)

    Reinert, Robert E.; Stewart, Donald; Seagran, Harry L.

    1972-01-01

    Concentrations of DDT residues were highest in parts of the body with the highest oil content in four species of fish from Lake Michigan: yellow perch (Perca flavescens), bloater (Coregonus hoyi), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch). Dressing reduced the DDT residues and oil content by more than 90% in yellow perch but had little effect in the other three species. The concentration of DDT residues in bloaters was changed little by smoking but was reduced 64–72% by other methods of cooking: from 8.0 ppm (raw) to 2.2 ppm after frying in corn oil; from 10.7 to 3.9 ppm after frying in lard; and from 9.1 to 3.2 ppm after broiling. The concentration of DDT residues in fillets of yellow perch changed only from 0.3 ppm (raw) to 0.4 or 0.5 ppm after baking, frying, or broiling.

  7. Fish abundance and distribution near three heated effluents to Lake Michigan

    International Nuclear Information System (INIS)

    Spigarelli, S.A.; Goldstein, R.M.; Prepejchal, W.; Thommes, M.M.

    1982-01-01

    A combined echo location-temperature mapping technique was used to determine the abundance and distribution of fish with depth and temperature in locally heated and unheated areas of Lake Michigan. Surveys were conducted between April and October at two adjacent power plants in the southern basin and at one plant in the northern basin of the lake. Fish densities in plume and reference areas differed seasonally. Densities typically differed by a factor of 2-4 although on one occasion plume area density was 90 times greater. Highest plume densities occurred during late spring when alewife (Alosa pseudoharengus) were spawning inshore. Consistently dense congregations of fish were found downstream of the interfaces between ambient shore-parallel currents and discharge flows. The general distribution of fish with depth was similar in all areas. Differences between plume and reference areas were related to the discharge type: at canal discharges fish tended to congregate inshore while at the offshore discharge they congregated in deeper zones. Fish also tended to occupy shallower depth strata in all plume areas. Positive correlation between fish density and increasing temperature was common at both plume and reference areas during all three seasons, but more frequent at plume areas. Temperatures selected by fish in plume areas were 1-3 0 C higher than maximum ambient temperatures

  8. Population structure of Cladophora-borne Escherichia coli in nearshore water of Lake Michigan.

    Science.gov (United States)

    Byappanahalli, Muruleedhara N; Whitman, Richard L; Shively, Dawn A; Ferguson, John; Ishii, Satoshi; Sadowsky, Michael J

    2007-08-01

    We previously reported that the macrophytic green alga Cladophora harbors high densities (up to 10(6) colony-forming units/g dry weight) of the fecal indicator bacteria, Escherichia coli and enterococci, in shoreline waters of Lake Michigan. However, the population structure and genetic relatedness of Cladophora-borne indicator bacteria remain poorly understood. In this study, 835 E. coli isolates were collected from Cladophora tufts (mats) growing on rocks from a breakwater located within the Indiana Dunes National Lakeshore in northwest Indiana. The horizontal fluorophore enhanced rep-PCR (HFERP) DNA fingerprinting technique was used to determine the genetic relatedness of the isolates to each other and to those in a library of E. coli DNA fingerprints. While the E. coli isolates from Cladophora showed a high degree of genetic relatedness (92% similarity), in most cases, however, the isolates were genetically distinct. The Shannon diversity index for the population was very high (5.39). Both spatial and temporal influences contributed to the genetic diversity. There was a strong association of isolate genotypes by location (79% and 80% for lake- and ditch-side samplings, respectively), and isolates collected from 2002 were distinctly different from those obtained in 2003. Cladophora-borne E. coli isolates represented a unique group, which was distinct from other E. coli isolates in the DNA fingerprint library tested. Taken together, these results indicate that E. coli strains associated with Cladophora may be a recurring source of indicator bacteria to the nearshore beach.

  9. Phytoplankton Communities in Green Bay, Lake Michigan after Invasion by Dreissenid Mussels: Increased Dominance by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Bart T. De Stasio

    2014-11-01

    Full Text Available Biological invasions of aquatic systems disrupt ecological communities, and cause major changes in diversity and ecosystem function. The Laurentian Great Lakes of North America have been dramatically altered by such invasions, especially zebra (Dreissena polymorpha and quagga (D. rostriformis bugensis mussels. Responses to mussel invasions have included increased water clarity, and decreased chlorophyll and phytoplankton abundance. Although not all systems have responded similarly, in general, mussels have changed nutrient dynamics and physical habitat conditions. Therefore examination of different impacts can help us further understand mechanisms that underlie ecosystem responses to biological invasions. To aid our understanding of ecosystem impacts, we sampled established locations along a well-studied trophic gradient in Green Bay, Lake Michigan, after the 1993 zebra mussel invasion. A strong trophic gradient remained during the period sampled after the mussel invasion (2000–2012. However, mean summer chlorophyll increased and other measures of phytoplankton biomass (microscope and electronic cell counting did not change significantly. Multivariate analyses of phytoplankton community structure demonstrate a significant community shift after the invasion. Cyanobacteria increased in dominance, with Microcystis becoming the major summer taxon in lower Green Bay. Diatom diversity and abundance also increased and Chlorophyta became rare. Phytoplankton responses along the trophic gradient of Green Bay to zebra mussel invasion highlight the importance of mussel effects on nutrient dynamics and phytoplankton diversity and function.

  10. Sediment processes and mercury transport in a frozen freshwater fluvial lake (Lake St. Louis, QC, Canada).

    Science.gov (United States)

    Canário, João; Poissant, Laurier; O'Driscoll, Nelson; Vale, Carlos; Pilote, Martin; Lean, David

    2009-04-01

    An open-bottom and a closed-bottom mesocosm were developed to investigate the release of mercury from sediments to the water column in a frozen freshwater lake. The mesoscosms were deployed in a hole in the ice and particulate mercury (Hg(P)) and total dissolved mercury (TDHg) were measured in sediments and in water column vertical profiles. In addition, dissolved gaseous mercury (DGM) in water and mercury water/airflux were quantified. Concentrations of TDHg, DGM, and mercury flux were all higher in the open-bottom mesocosm than in the closed-bottom mesocosm. In this paper we focus on the molecular diffusion of mercury from the sediment in comparison with the TDHg accumulation in the water column. We conclude that the molecular diffusion and sediment resuspension play a minor role in mercury release from sediments suggesting that solute release during ebullition is an important transport process for mercury in the lake.

  11. The environmental state of Lake Ladoga sediments, Russia

    International Nuclear Information System (INIS)

    Pellinen, J.; Ristola, T.; Kukkonen, J.; Leppaenen, M.; Hoof, P.L. van; Robbins, J.A.

    1994-01-01

    The authors collected sediments in the summer 1993 from Lake Ladoga for chemical analyses and toxicity tests to assess the state of the lake. The sediments were analyzed for heavy metals, fluorides, chlorinated hydrocarbons, polyaromatic hydrocarbons, and certain radionuclides related to the fallout from the Chernobyl accident. In general, the concentrations of toxic chemicals were low. Most chemicals were below the limit of detection. The range of the total concentration of 17 PCB congeners was from 6 to 30 ng/kg dw; the highest value was at the pulp and paper mill located in the northeastern shore of the lake (Pitkaeranta). The highest concentrations of Cr, Co, Ni, Cu, Zn, Pb were 10, 42, 46, 36, 188, and 143 μg/g dw, respectively. Arsene was not detected at all and Cd only at one out of 12 sites studied. The toxicological testing with larvae of a midge, Chironomus riparius, and Daphnia magna resulted in only slight effects which may in part be related to different physical characteristics of the sediments rather than to toxic effects. The highest mortality was 75% at the deepest part of the lake (close to Valamo Island) which was believed to be the least polluted. The highest heavy metal concentrations and slow development of the larvae were observed for the same site. In the south of the lake at the Volhov Bay which receives effluents from forest and aluminum industry, the mortality was 10--50%

  12. Heavy metal speciation and their accumulation in sediments of Lake ...

    African Journals Online (AJOL)

    UFUOMA

    Key words: Heavy metals, chemical speciation, sediments, Burullus, Lake. INTRODUCTION ..... fuel for use in internal combustion engines and in making batteries. ..... (Tuner, 1989). According to this model, human risk assessment was .... 593 - 594. Hökanson L (1980). "Ecological Risk Index for Aquatic Pollution. Control.

  13. The release of dissolved phosphorus from lake sediments

    NARCIS (Netherlands)

    Boers, P.C.M.

    1991-01-01

    Chapter 1. Introduction: Eutrophication is one of the world's major water quality problems. Attempts to alleviate eutrophication of lakes have involved the control of phosphorus loadings. In such cases, an internal loading of phosphorus from the sediments may

  14. Multi-Elements in Waters and Sediments of Shallow Lakes: Relationships with Water, Sediment, and Watershed Characteristics.

    Science.gov (United States)

    Kissoon, La Toya T; Jacob, Donna L; Hanson, Mark A; Herwig, Brian R; Bowe, Shane E; Otte, Marinus L

    2015-06-01

    We measured concentrations of multiple elements, including rare earth elements, in waters and sediments of 38 shallow lakes of varying turbidity and macrophyte cover in the Prairie Parkland (PP) and Laurentian Mixed Forest (LMF) provinces of Minnesota. PP shallow lakes had higher element concentrations in waters and sediments compared to LMF sites. Redundancy analysis indicated that a combination of site- and watershed-scale features explained a large proportion of among-lake variability in element concentrations in lake water and sediments. Percent woodland cover in watersheds, turbidity, open water area, and macrophyte cover collectively explained 65.2 % of variation in element concentrations in lake waters. Sediment fraction smaller than 63 µm, percent woodland in watersheds, open water area, and sediment organic matter collectively explained 64.2 % of variation in element concentrations in lake sediments. In contrast to earlier work on shallow lakes, our results showed the extent to which multiple elements in shallow lake waters and sediments were influenced by a combination of variables including sediment characteristics, lake morphology, and percent land cover in watersheds. These results are informative because they help illustrate the extent of functional connectivity between shallow lakes and adjacent lands within these lake watersheds.

  15. Strontium-90 in the bottom sediments of some Finnish lakes

    Energy Technology Data Exchange (ETDEWEB)

    Ilus, E.; Puhakainen, M.; Saxen, R

    1999-07-01

    The {sup 90}Sr concentrations in surface waters varied from 14 to 29 Bq m{sup -3} in 1988 and from 16 to 23 Bq m{sup -3} in 1990. In Lake Pielinen almost all the {sup 90}Sr seemed to originate from weapons test fallout, whereas in Lakes Ontojaervi, Naesijaervi and Pyhaejaervi the share of the Chernobyl fallout was equal to that of weapons test fallout. In the sediments, the total amount of {sup 90}Sr per square metre varied from 97 to 1060 Bq m{sup -2} in 1988 and from 310 to 1160 Bq m{sup -2} in 1990. The maximum values occurred in Lake Naesijaervi. The local amount of deposition and the type of sediment were the most important factors affecting strontium values in sediments. In addition, the large variation in total amounts of {sup 90}Sr was due to other environmental factors. The total amounts of {sup 90}Sr in sediments were generally of the same order of magnitude as the {sup 90}Sr deposition on the ground in the area. The concentrations of {sup 90}Sr in surface waters also conformed quite well to the distribution pattern of the deposition values. At some stations there was a clear maximum in a deeper sediment layer, which could be construed as a marker of the nuclear weapons tests in the 1960s. (orig.)

  16. Possible pitfalls in the search for uranium deposits using lake sediments and lake waters

    International Nuclear Information System (INIS)

    Levinson, A.A.; Bland, C.J.

    1978-01-01

    The organic-rich sediments from the centres of Canadian lakes are a valuable sampling medium in the search for uranium. However, because of the young age of hydromorphically transported uranium in these sediments, which must post-date the last period of glaciation, there has been insufficient time for the isotope 214 Bi to reach equilibrium with its ancestor 238 U. This results in equivalent uranium (eU) values significantly lower than actual uranium values determined by fluorometry or delayed neutron activation analysis. Radiometric ( 226 Ra) analyses of 12 centre-lake sediments from Seahorse Lake, Saskatchewan illustrate the potential pitfalls which may be encountered using gamma-ray spectrometry, as only 3-8% of the actual uranium present in most of the samples would have been detected. (author)

  17. Geochemistry records from laminated sediments of Shira Lake (Russian Asia)

    Science.gov (United States)

    Phedorin, M.; Vologina, E.; Drebuschak, M.; Tolomeev, A.; Kirichenko, I.; Toyabin, A.

    2009-04-01

    We measured downcore elements distributions in five cores collected across the Shira Lake situated in Central part of Asia (E90o12', N54o30'). The lake is small (32km2), saline (ca.20g/l SO4-, Cl-, Na+, Mg+, K+), being filled with regional precipitation of about 300mm/year (mainly through one major tributary, river Son) and has no surface outflow. The aim of our study was to reconstruct history of changes in the regime of the lake that happened both before and during period of instrumental meteorological observations. In particular, we were interested in lake-level changes due to evaporation, water supply from surface and from underground sources, and in changes of bioproduction in the lake as well. To construct depth-age model for the cores, we measured Cs-137 and unsupported Pb-210 in top layers of the cores. The sedimentation rate thus identified varied in the range of 1-2 mm/year for different cores. We visually observed fine sedimentation ‘rhythms' having thickness of about 0.x-2.x mm: these layers may now be reliably identified as annual lamination. We also determined concentrations of elements in the sediments by recording x-ray fluorescence (XRF) spectra when continuously scanning the halves of the cores under sharp synchrotron radiation (SR) beam, using an instrument described in (Zolotarev et al., 2001). The resolution of the scanning was 0.1 mm. After processing of the measured XRF-SR data as in (Phedorin and Goldberg, 2005) we obtained downcore records of 20 elements. We correlated all five cores employing elements patterns. We qualitatively identified variations in surface-water supply treating markers of ‘clastic' material (Ti, Rb, Zr). We identified downcore variations in authgenic mineralization, which appeared to have different kinds: Ca-related, Sr-related, Ba-related, Fe-related. We tried to assess biogenic production changes from Br distribution, admitting analogy of Br in Shira sediments to Br in Lake Baikal sediments (Phedorin et al., 2000

  18. Episodes of low dissolved oxygen indicated by ostracodes and sediment geochemistry at Crystal Lake, Illinois, USA

    Science.gov (United States)

    Curry, B. Brandon; Filippelli, G.M.

    2010-01-01

    Low dissolved oxygen during the summer and early fall controls profundal continental ostracode distribution in Crystal Lake (McHenry County), Illinois, favoring Cypria ophthalmica and Physocypria globula at water depths from 6 to 13 m. These species also thrived in the lake's profundal zone from 14,165 to 9600 calendar year before present (cal yr b.p.) during the late Boiling, Allerod, and Younger Dryas chronozones, and early Holocene. Characterized by sand, cemented tubules, large aquatic gastropod shells, and littoral ostracode valves, thin (1-6 cm) tempestite deposits punctuate thicker deposits of organic gyttja from 16,080 to 11,900 cal yr b.p. The succeeding 2300 yr (11,900-9600 cal yr b.p.) lack tempestites, and reconstructed water depths were at their maximum. Deposition of marl under relatively well-oxygenated conditions occurred during the remainder of the Holocene until the arrival of Europeans, when the lake returned to a pattern of seasonally low dissolved oxygen. Such conditions are also indicated in the lake sediment by the speciation of phosphorus, high concentrations of organic carbon, and abundant iron and manganese occluded to mineral grains. Initial low dissolved oxygen was probably caused by the delivery of dissolved P and Fe in shallow groundwater, the chemistry of which was influenced by Spodosol pedogenesis under a spruce forest. The triggering may have been regionally warm and wet conditions associated with retreat of the Lake Michigan lobe (south-central Laurentide Ice Sheet). ?? 2010, by the American Society of Limnology and Oceanography Inc.

  19. A sediment resuspension and water quality model of Lake Okeechobee

    Science.gov (United States)

    James, R.T.; Martin, J.; Wool, T.; Wang, P.-F.

    1997-01-01

    The influence of sediment resuspension on the water quality of shallow lakes is well documented. However, a search of the literature reveals no deterministic mass-balance eutrophication models that explicitly include resuspension. We modified the Lake Okeeehobee water quality model - which uses the Water Analysis Simulation Package (WASP) to simulate algal dynamics and phosphorus, nitrogen, and oxygen cycles - to include inorganic suspended solids and algorithms that: (1) define changes in depth with changes in volume; (2) compute sediment resuspension based on bottom shear stress; (3) compute partition coefficients for ammonia and ortho-phosphorus to solids; and (4) relate light attenuation to solids concentrations. The model calibration and validation were successful with the exception of dissolved inorganic nitrogen species which did not correspond well to observed data in the validation phase. This could be attributed to an inaccurate formulation of algal nitrogen preference and/or the absence of nitrogen fixation in the model. The model correctly predicted that the lake is lightlimited from resuspended solids, and algae are primarily nitrogen limited. The model simulation suggested that biological fluxes greatly exceed external loads of dissolved nutrients; and sedimentwater interactions of organic nitrogen and phosphorus far exceed external loads. A sensitivity analysis demonstrated that parameters affecting resuspension, settling, sediment nutrient and solids concentrations, mineralization, algal productivity, and algal stoichiometry are factors requiring further study to improve our understanding of the Lake Okeechobee ecosystem.

  20. Sediment Source Fingerprinting of the Lake Urmia Sand Dunes.

    Science.gov (United States)

    Ahmady-Birgani, Hesam; Agahi, Edris; Ahmadi, Seyed Javad; Erfanian, Mahdi

    2018-01-09

    Aeolian sand dunes are continuously being discovered in inner dry lands and coastal areas, most of which have been formed over the Last Glacial Maximum. Presently, due to some natural and anthropogenic implications on earth, newly-born sand dunes are quickly emerging. Lake Urmia, the world's second largest permanent hypersaline lake, has started shrinking, vast lands comprising sand dunes over the western shore of the lake have appeared and one question has been playing on the minds of nearby dwellers: where are these sand dunes coming from, What there was not 15 years ago!! In the present study, the determination of the source of the Lake Urmia sand dunes in terms of the quantifying relative contribution of each upstream geomorphological/lithological unit has been performed using geochemical fingerprinting techniques. The findings demonstrate that the alluvial and the fluvial sediments of the western upstream catchment have been transported by water erosion and they accumulated in the lower reaches of the Kahriz River. Wind erosion, as a secondary agent, have carried the aeolian sand-sized sediments to the sand dune area. Hence, the Lake Urmia sand dunes have been originating from simultaneous and joint actions of alluvial, fluvial and aeolian processes.

  1. Historical variations of Bera Lake (Malaysia) sediments geochemistry using radioisotopes and sediment quality indices

    International Nuclear Information System (INIS)

    Mohammadreza Gharibreza; John Kuna Raj; Ismail Yusoff; Zainudin Othman; Wan Zakaria Wan Muhamad Tahir; Muhammad Aqeel Ashraf

    2013-01-01

    The Bera Lake basin is a lacustrine mire system and the largest natural lake in Peninsular Malaysia. Three cores were collected from the lake sediments in order to assess sediment quality and ecological risks for aquatic life and human health. An index analysis approach (C f , C d , E r , and IR) and fallout 210 Pb and 137 Cs radioisotopes were applied to assess the impacts of environmental evolutionary changes. Sediment chronology was determined using the Constant Rate of Supply model with the resultant ages verified by 137 Cs horizons. Although the general contamination factors indicate low risk conditions in Bera Lake the risks associated with individual layers ranged from moderate to considerable. Five deforestation phases can be identified in the dated sediment cores with distinct variations in heavy metal influxes since 1972. These phases are in excellent agreement with the dates of land clearance and development projects undertaken over the past four decades. This study has highlighted the capability of contamination factors and chronological methods in environmental evolutionary studies where catchments have experienced extensive land use changes. The destiny of heavy metal influxes into a lake can also be revealed using this methodology. (author)

  2. Mono Lake sediments preserve a record of recent environmental change

    Science.gov (United States)

    Meixnerova, J.; Betts, M.; Westacott, S.; Ingalls, M.; Miller, L. G.; Sessions, A. L.; Trower, L.; Geobiology Course, A.

    2017-12-01

    Modern Mono Lake is a geochemically unique closed-basin, hypersaline soda lake. Since 1941, anthropogenic water diversions have decreased the lake's volume and water level, driving changes in water chemistry and ecology. Mono Lake sediments offer an opportunity to investigate the nature and extent of these changes. We analyzed a 70 cm sediment core from the center of Mono Lake recording the past 116 years of deposition. At the time of recovery, the entire core was dark green. 16S rRNA gene analysis indicated a sedimentary bacterial community dominated by Cyanobacteria. SEM imaging revealed abundant, well-preserved diatom frustules below 10 cm core depth, in contrast they are nearly absent above 10 cm depth. Fatty acid (FAME) biomarkers for diatoms and algal sterols were present throughout the core in varying concentrations. Phytol was exceptionally abundant in the core; ratios of phytol/C-18 FAME were commonly >200. The δ13Corg ranged between -17.5 and -20‰ in the lower 52 cm of the core while the upper part shows significant decrease of δ13Corg to -28‰. We interpret the shift in δ13Corg as an ecological transition from mainly diatoms in the lower core towards the green alga Picocystis, which is the main primary producer today and has a δ13Corg value of -32.5‰. The onset of this change dates back 23 years, which roughly coincides with the highest reported salinity, 88 g/L in 1995. We hypothesize that diatoms gradually became marginalized as a result of hypersaline conditions. We also observed a variety of trends that may be characterized as unique fingerprints of Mono Lake. The unusually high abundance of phytol was consistent with the core's pervasive green coloring and could potentially indicate a higher preservation potential of phytol under alkaline conditions. Throughout the core, δ15Norg fluctuated between +10 and +13‰. Such atypical enrichment in δ15Norg could be explained by NH4 dissociation and subsequent NH3 volatilization under high p

  3. AMS radiocarbon analyses from Lake Baikal, Siberia: Challenges of dating sediments from a large, oligotrophic lake

    Science.gov (United States)

    Colman, Steven M.; Jones, Glenn A.; Rubin, M.; King, J.W.; Peck, J.A.; Orem, W.H.

    1996-01-01

    A suite of 146 new accelerator-mass spectrometer (AMS) radiocarbon ages provides the first reliable chronology for late Quaternary sediments in Lake Baikal. In this large, highly oligotrophic lake, biogenic and authigenic carbonate are absent, and plant macrofossils are extremely rare. Total organic carbon is therefore the primary material available for dating. Several problems are associated with the TOC ages. One is the mixture of carbon sources in TOC, not all of which are syndepositional in age. This problem manifests itself in apparent ages for the sediment surface that are greater than zero. However, because most of the organic carbon in Lake Baikal sediments is algal (autochthonous) in origin, this effect is limited to about 1000+500 years, which can be corrected, at least for young deposits. The other major problem with dating Lake Baikal sediments is the very low carbon contents of glacial-age deposits, which makes them extremely susceptible to contamination with modern carbon. This problem can be minimized by careful sampling and handling procedures. The ages show almost an order of magnitude difference in sediment-accumulation rates among different sedimentary environments in Lake Baikal, from about 0.04 mm/year on isolated banks such as Academician Ridge, to nearly 0.3 mm/year in the turbidite depositional areas beneath the deep basin floors, such as the Central Basin. The new AMS ages clearly indicate that the dramatic increase in diatom productivity in the lake, as evidenced by increases in biogenic silica and organic carbon, began about 13 ka, in contrast to previous estimates of 7 ka for the age of this transition. Holocene net sedimentation rates may be less than, equal to, or greater than those in the late Pleistocene, depending on the site. This variability reflects the balance between variable terrigenous sedimentation and increased biogenic sedimentation during interglaciations. The ages reported here, and the temporal and spatial variation in

  4. Concentration of PCB Aroclors, Total Organic Carbon (TOC), and other parameters, Manistique Harbor, Lake Michigan, 2012-09-17 to 2012-09-21 (NCEI Accession 0151632)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project was part of a team effort by NOAA, the EPA, the State of Michigan, and the USGS to collect samples of sediments within the Manistique Harbor Area of...

  5. Tumours in white suckers from Lake Michigan tributaries: Pathology and prevalence

    Science.gov (United States)

    Blazer, Vicki S.; Walsh, H.L.; Braham, R.P.; Hahn, C. M.; Mazik, P.; McIntyre, P.B.

    2016-01-01

    The prevalence and histopathology of neoplastic lesions were assessed in white suckerCatostomus commersonii captured at two Lake Michigan Areas of Concern (AOCs), the Sheboygan River and Milwaukee Estuary. Findings were compared to those observed at two non-AOC sites, the Root and Kewaunee rivers. At each site, approximately 200 adult suckers were collected during their spawning migration. Raised skin lesions were observed at all sites and included discrete white spots, mucoid plaques on the body surface and fins and large papillomatous lesions on lips and body. Microscopically, hyperplasia, papilloma and squamous cell carcinoma were documented. Liver neoplasms were also observed at all sites and included both hepatocellular and biliary tumours. Based on land use, the Kewaunee River was the site least impacted by human activities previously associated with fish tumours and had significantly fewer liver neoplasms when compared to the other sites. The proportion of white suckers with liver tumours followed the same patterns as the proportion of urban land use in the watershed: the Milwaukee Estuary had the highest prevalence, followed by the Root, Sheboygan and Kewaunee rivers. The overall skin neoplasm (papilloma and carcinoma) prevalence did not follow the same pattern, although the percentage of white suckers with squamous cell carcinoma exhibited a similar relationship to land use. Testicular tumours (seminoma) were observed at both AOC sites but not at the non-AOC sites. Both skin and liver tumours were significantly and positively associated with age but not sex.

  6. Determination of inositol phosphate ester in lake sediments

    International Nuclear Information System (INIS)

    Weimer, W.C.; Armstrong, D.E.

    1977-01-01

    A procedure for the determination of the total inositol polyphosphate content of lake sediments is presented and evaluated. This technique involves extraction with NaOH, cleanup of the extract, and isolation and identification of two groups of inositol phosphate esters by ion-exchange chromatography. Radioisotope dilution is employed to correct for losses during the extraction, cleanup and isolation steps. Recoveries of the radiotracer inositol phosphates have averaged 85% during the analysis of approximately 40 calcareous and non-calcareous sediment samples and more than 20 soil samples

  7. pH dependent dissolution of sediment aluminum in six Danish lakes treated with aluminum

    DEFF Research Database (Denmark)

    Reitzel, Kasper; Jensen, Henning S.; Egemose, Sara

    2013-01-01

    The possible pH dependent dissolution of aluminum hydroxides (Al(OH)(3)) from lake sediments was studied in six lakes previously treated with Al to bind excess phosphorus (P). Surface sediment was suspended for 2 h in lake water of pH 7.5, 8.5, or 9.5 with resulting stepwise increments in dissolved...

  8. Trace elements in lake sediments measured by the PIXE technique

    International Nuclear Information System (INIS)

    Gatti, Luciana V.; Mozeto, Antonio A.; Artaxo, Paulo

    1999-01-01

    Lakes are ecosystems where there is a great potential of metal accumulation in sediments due to their depositional characteristics. Total concentration of trace elements was measured on a 50 cm long sediment core from the Infernao Lake, that is an oxbow lake of the Moji-Guacu River basin, in the state of Sao Paulo, Brazil. Dating of the core shows up to 180 yrs old sediment layers. The use of the PIXE technique for elemental analysis avoids the traditional acid digestion procedure common in other techniques. The multielemental characteristic of PIXE allows a simultaneous determination of about 20 elements in the sediment samples, such as, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Zr, Ba, and Pb. Average values for the elemental composition were found to be similar to the bulk crustal composition. The lake flooding pattern strongly influences the time series of the elemental profiles. Factor analysis of the elemental variability shows five factors. Two of the factors represent the mineralogical matrix, and others represent the organic component, a factor with lead, and another loaded with chromium. The mineralogical component consists of elements such as, Fe, Al, V, Ti, Mn, Ni, K, Zr, Sr, Cu and Zn. The variability of Si is explained by two distinct factors, because it is influenced by two different sources, aluminum-silicates and quartz, and the effect of inundation are different for each other. The organic matter is strongly associated with calcium, and also bounded with S, Zn, Cu and P. Lead and chromium appears as separated factors, although it is not clear the evidences for their anthropogenic origin. The techniques developed for sample preparation and PIXE analysis was proven as advantageous and provided very good reproducibility and accuracy

  9. Radioisotope Concentration in Lake Sediments of Maracaibo, Venezuela

    International Nuclear Information System (INIS)

    Salas, A. Rangel; Viloria, T.; Sajo-Bohus, L.; Barros, H.; Greaves, E. D.; Palacios, D.

    2007-01-01

    Maracaibo Lake is one of the most important water basing and oil producing regions in Venezuela. Changes in the local environment have been monitored for chemical pollution in the past. For this study we selected a set of sediment samples collected in the shore and analyzed for its radioisotope content. Results show the gamma emitting isotopes distribution. Isotopes concentrations have been determined within the natural K, Th and U families

  10. Mesoscale spiral vortex embedded within a Lake Michigan snow squall band - High resolution satellite observations and numerical model simulations

    Science.gov (United States)

    Lyons, Walter A.; Keen, Cecil S.; Hjelmfelt, Mark; Pease, Steven R.

    1988-01-01

    It is known that Great Lakes snow squall convection occurs in a variety of different modes depending on various factors such as air-water temperature contrast, boundary-layer wind shear, and geostrophic wind direction. An exceptional and often neglected source of data for mesoscale cloud studies is the ultrahigh resolution multispectral data produced by Landsat satellites. On October 19, 1972, a clearly defined spiral vortex was noted in a Landsat-1 image near the southern end of Lake Michigan during an exceptionally early cold air outbreak over a still very warm lake. In a numerical simulation using a three-dimensional Eulerian hydrostatic primitive equation mesoscale model with an initially uniform wind field, a definite analog to the observed vortex was generated. This suggests that intense surface heating can be a principal cause in the development of a low-level mesoscale vortex.

  11. Sedimentation rates and erosion changes recorded in recent sediments of Lake Piaseczno, south-eastern Poland

    Science.gov (United States)

    Tylmann, Wojciech; Turczyński, Marek; Kinder, Małgorzata

    2009-10-01

    This paper presents the dating results and basic analyses of recent sediments from Lake Piaseczno. The age of sediments was determined using the 210Pb method and constant flux: constant sedimentation (CF: CS) model. The estimated timescale was in agreement with the AMS14C date from the base of the core. The mean sediment accumulation rate during the last 100 years was calculated as 0.025 g cm-2 a-1. Based on the radiocarbon date, the rate of sediment accumulation below the 210Pb dating horizon was estimated as 0.066 g cm-2 a-1. The variability of main physical properties and sediment components along the core was analysed as well. The sediments were characterised by a very high water content (>80%). Carbonates were either not present or at a very low level (interesting record of increasing erosion intensity in the catchment area. Analysis of archival cartographic materials demonstrated that the most likely reason for the enhanced transport of minerogenic matter to the lake was deforestation caused by human activity in the beginning of the 20th century.

  12. Polycyclic aromatic hydrocarbons (PAHs) in surface sediments of two lakes of the Dongting Lake district in Hunan, China

    Science.gov (United States)

    He, Jiang; Yang, Yajing; Zhang, Lugang; Luo, Yushuang; Liu, Fei; Yang, Pinhong

    2018-04-01

    In this paper, 18 and 12 surface sediment samples were collected from Datong Lake and Shanpo Lake, respectively, and the 16 USEPA priority Polycyclic aromatic hydrocarbons (PAHs) in these samples were detected. The result indicated that the Σ16PAHs ranged from 206.56 to 1058.98 ng.g-1 with an average concentration of 667.22 ng.g-1 in sediments from Datong Lake, whereas it ranged from 90.62 to 900.70 ng.g-1 with an average concentration of 364.97 ng.g-1 in sediments from Shanpo Lake. The concentrations of individual PAHs in sediments ranged from 5.50 to 85.23 and from 4.39 to 52.74 ng.g-1 in Datong Lake and Shanpo Lake, respectively. According to the indexes such as HMW/LMW, Ant/(Ant+Phe), Flua/(Flua+Pyr), IcdP/(IcdP+BghiP), and BaA/(BaA+Chr), the PAHs in sediments from both lakes are mainly of pyrogenic origin. The total BaP equivalent in the surface sediment samples from Datong Lake and Shanpo Lake is 42.77 and 33.35 ng.g-1, respectively.

  13. Lake sediments as natural seismographs: Earthquake-related deformations (seismites) in central Canadian lakes

    Science.gov (United States)

    Doughty, M.; Eyles, N.; Eyles, C. H.; Wallace, K.; Boyce, J. I.

    2014-11-01

    Central Canada experiences numerous intraplate earthquakes but their recurrence and source areas remain obscure due to shortness of the instrumental and historic records. Unconsolidated fine-grained sediments in lake basins are 'natural seismographs' with the potential to record ancient earthquakes during the last 10,000 years since the retreat of the Laurentide Ice Sheet. Many lake basins are cut into bedrock and are structurally-controlled by the same Precambrian basement structures (shear zones, terrane boundaries and other lineaments) implicated as the source of ongoing mid-plate earthquake activity. A regional seismic sub-bottom profiling of lakes Gull, Muskoka, Joseph, Rousseau, Ontario, Wanapitei, Fairbanks, Vermilion, Nipissing, Georgian Bay, Mazinaw, Simcoe, Timiskaming, Kipawa, Parry Sound and Lake of Bays, encompassing a total of more than 2000 kilometres of high-resolution track line data supplemented by multibeam and sidescan sonar survey records show a consistent sub-bottom stratigraphy of relatively-thick lowermost lateglacial facies composed of interbedded semi-transparent mass flow facies (debrites, slumps) and rhythmically-laminated silty-clays. Mass flows together with cratered ('kettled') lake floors and associated deformations reflect a dynamic ice-contact glaciolacustrine environment. Exceptionally thick mass flow successions in Lake Timiskaming along the floor of the Timiskaming Graben within the seismically-active Western Quebec Seismic Zone (WQSZ), point to a higher frequency of earthquakes and slope failure during deglaciation and rapid glacio-isostatic rebound though faulting continues into the postglacial. Lateglacial faulting, diapiric deformation and slumping of coeval lateglacial sediments is observed in Parry Sound, Lake Muskoka and Lake Joseph, which are all located above prominent Precambrian terrane boundaries. Lateglacial sediments are sharply overlain by relatively-thin rhythmically-laminated and often semi

  14. Lead-210 analyses of sediment accumulation rates in five Southern Illinois surface mine lakes

    International Nuclear Information System (INIS)

    Brugam, R.B.; Carlson, M.A.

    1981-01-01

    210 Pb is a naturally occurring radionuclide with a short half-life (22 yrs) which can be used to determine sedimentation rates in lakes. The technique was applied in 5 Southern Illinois surface mine lakes where it revealed past sedimentation rates to have been extremely variable. In some of the lakes there was evidence for extensive slumping immediately after mining ceased followed by a more regular sedimentary regime that continued until the present. In others there have been one or more changes in sediment accumulation rates since lacustrine sedimentation began. These results suggest that simply measuring the amount of sediment that has accumulated in a surface mine lake since mining ceased is inadequate to determine filling rates. Sedimentation rates in the 5 lakes varied from .60 +- .19 to 1.46 +- .19 cm/y. These rates are similar to natural lakes with moderately disturbed watersheds

  15. Logarithmic velocity structure in the deep hypolimnetic waters of Lake Michigan

    Science.gov (United States)

    Troy, Cary; Cannon, David; Liao, Qian; Bootsma, Harvey

    2016-01-01

    The characteristics of the bottom boundary layer are reported from a Lake Michigan field study carried out in deep hypolimnetic waters (55 m depth) during the stratified period (June-September 2012). The sandy substrate at the measurement site was densely covered with invasive quagga mussels (mean size: 1.6 cm; mean density: 10,000 mussels m-2). The measurements reveal a sluggish, compact bottom boundary layer, with flow speeds at 1 mab less than 5 cm s-1 for most of the period, and a dominance of subinertial energy. A downwelling event caused the largest currents observed during the deployment (10 cm s-1 at 1 mab) and a logarithmic layer thickness of 15 m. In spite of the weak flow, logarithmic profile fitting carried out on high-resolution, near-bed velocity profiles show consistent logarithmic structure (90% of profiles). Flow was dominated by subinertial energy but strong modified by near-inertial waves. Fitted drag coefficients and roughness values are = 0.004 and = 0.12 cm, respectively. These values increase with decreasing flow speed, but approach canonical values for 1 mab flow speeds exceeding 4 cm s-1. The estimated vertical extent of the logarithmic region was compact, with a mean value of 1.2 m and temporal variation that is reasonably described by Ekman scaling, 0.07 /, and the estimated overall Ekman layer thickness was generally less than 10 m. Near-bed dissipation rates inferred from the law of the wall were 10-8-10-7 W kg-1 and turbulent diffusivities were 10-4-10-3 m2s-1.

  16. Budget analysis of Escherichia coli at a southern Lake Michigan Beach

    Science.gov (United States)

    Thupaki, P.; Phanikumar, M.S.; Beletsky, D.; Schwab, D.J.; Nevers, M.B.; Whitman, R.L.

    2010-01-01

    Escherichia coli (EC) concentrations at two beaches impacted by river plume dynamics in southern Lake Michigan were analyzed using three-dimensional hydrodynamic and transport models. The relative importance of various physical and biological processes influencing the fate and transport of EC were examined via budget analysis and a first-order sensitivity analysis of model parameters. The along-shore advective fluxofEC(CFU/m2·s)was found to be higher compared to its crossshore counterpart; however, the sum of diffusive and advective components was of a comparable magnitude in both directions showing the importance of cross-shore exchange in EC transport. Examination of individual terms in the EC mass balance equation showed that vertical turbulent mixing in the water column dominated the overall EC transport for the summer conditions simulated. Dilution due to advection and diffusion accounted for a large portion of the total EC budget in the nearshore, and the net EC loss rate within the water column (CFU/m3·s) was an order of magnitude smaller compared to the horizontal and vertical transport rates. This result has important implications for modeling EC at recreational beaches; however, the assessment of the magnitude of EC loss rate is complicated due to the strong coupling between vertical exchange and depth-dependent EC loss processes such as sunlight inactivation and settling. Sensitivity analysis indicated that solar inactivation has the greatest impact on EC loss rates. Although these results are site-specific, they clearly bring out the relative importance of various processes involved.

  17. Comparison of the distribution coefficients of plutonium and other radionuclides in Lake Michigan to those in other systems

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Nelson, D.M.

    1976-01-01

    Filtration of Lake Michigan water samples has been carried out routinely since 1973, and some plutonium concentrations in the seston have been reported. During 1975 and 1976 a sufficient number of filter samples from various depths was obtained throughout the field seasons to establish whether or not a distribution coefficient also controls the uptake of plutonium by the formation of particulates and their settling from the surface waters. Samples from ANL station 5 (10 km SW of Grand Haven, Michigan, water depth 67 m), of the southern basin, and from the lower Great Lakes have been analyzed for dry weight, ash weight, total organic (loss of weight on ignition), amorphous silica, calcite, and residual minerals. Distribution coefficients were calculated on the basis of each of these solid components, and self-consistent values were observed for depth, season, or lake only, on the basis of dry weight of seston. The findings strongly suggest that the uptake of fallout plutonium (including inputs of new fallout during the summer of 1975) is dominated by a surface coating process common to all seston particle types. An insufficient number of 137 Cs analyses were obtained to correlate its uptake to a specific component of the seston, but its behavior is clearly different from that of plutonium

  18. Lake sediment records on climate change and human activities in the Xingyun Lake catchment, SW China.

    Science.gov (United States)

    Zhang, Wenxiang; Ming, Qingzhong; Shi, Zhengtao; Chen, Guangjie; Niu, Jie; Lei, Guoliang; Chang, Fengqin; Zhang, Hucai

    2014-01-01

    Sediments from Xinyun Lake in central Yunnan, southwest China, provide a record of environmental history since the Holocene. With the application of multi-proxy indicators (total organic carbon (TOC), total nitrogen (TN), δ13C and δ15N isotopes, C/N ratio, grain size, magnetic susceptibility (MS) and CaCO3 content), as well as accelerator mass spectrometry (AMS) 14C datings, four major climatic stages during the Holocene have been identified in Xingyun's catchment. A marked increase in lacustrine palaeoproductivity occurred from 11.06 to 9.98 cal. ka BP, which likely resulted from an enhanced Asian southwest monsoon and warm-humid climate. Between 9.98 and 5.93 cal. ka BP, a gradually increased lake level might have reached the optimum water depth, causing a marked decline in coverage by aquatic plants and lake productivity of the lake. This was caused by strong Asian southwest monsoon, and coincided with the global Holocene Optimum. During the period of 5.60-1.35 cal. ka BP, it resulted in a warm and dry climate at this stage, which is comparable to the aridification of India during the mid- and late Holocene. The intensifying human activity and land-use in the lake catchment since the early Tang Dynasty (∼1.35 cal. ka BP) were associated with the ancient Dian culture within Xingyun's catchment. The extensive deforestation and development of agriculture in the lake catchment caused heavy soil loss. Our study clearly shows that long-term human activities and land-use change have strongly impacted the evolution of the lake environment and therefore modulated the sediment records of the regional climate in central Yunnan for more than one thousand years.

  19. Lake sediment records on climate change and human activities in the Xingyun Lake catchment, SW China.

    Directory of Open Access Journals (Sweden)

    Wenxiang Zhang

    Full Text Available Sediments from Xinyun Lake in central Yunnan, southwest China, provide a record of environmental history since the Holocene. With the application of multi-proxy indicators (total organic carbon (TOC, total nitrogen (TN, δ13C and δ15N isotopes, C/N ratio, grain size, magnetic susceptibility (MS and CaCO3 content, as well as accelerator mass spectrometry (AMS 14C datings, four major climatic stages during the Holocene have been identified in Xingyun's catchment. A marked increase in lacustrine palaeoproductivity occurred from 11.06 to 9.98 cal. ka BP, which likely resulted from an enhanced Asian southwest monsoon and warm-humid climate. Between 9.98 and 5.93 cal. ka BP, a gradually increased lake level might have reached the optimum water depth, causing a marked decline in coverage by aquatic plants and lake productivity of the lake. This was caused by strong Asian southwest monsoon, and coincided with the global Holocene Optimum. During the period of 5.60-1.35 cal. ka BP, it resulted in a warm and dry climate at this stage, which is comparable to the aridification of India during the mid- and late Holocene. The intensifying human activity and land-use in the lake catchment since the early Tang Dynasty (∼1.35 cal. ka BP were associated with the ancient Dian culture within Xingyun's catchment. The extensive deforestation and development of agriculture in the lake catchment caused heavy soil loss. Our study clearly shows that long-term human activities and land-use change have strongly impacted the evolution of the lake environment and therefore modulated the sediment records of the regional climate in central Yunnan for more than one thousand years.

  20. Holocene evolution of the Tonle Sap Lake: valley network infill and rates of sedimentation in Cambodia's Great Lake

    Science.gov (United States)

    Best, J.; Darby, S. E.; Langdon, P. G.; Hackney, C. R.; Leyland, J.; Parsons, D. R.; Aalto, R. E.; Marti, M.

    2017-12-01

    Tonle Sap Lake, the largest freshwater lake in SE Asia (c. 120km long and 35 km wide), is a vital ecosystem that provides 40-60% of the protein for the population of Cambodia. The lake is fed by flow from the Mekong River that causes the lake rise in level by c. 8m during monsoonal and cyclone-related floods, with drainage of the lake following the monsoon. Hydropower dam construction on the Mekong River has raised concerns as to the fragility of the Tonle Sap habitat due to any changing water levels and sedimentation rates within the lake. This paper details results of sub-bottom profiling surveys of Tonle Sap Lake in October 2014 that detailed the stratigraphy of the lake and assessed rates of infill. An Innomar Parametric Echo Sounder (PES) was used to obtain c. 250 km of sub-bottom profiles, with penetration up to 15m below the lake bed at a vertical resolution of c. 0.20m. These PES profiles were linked to cores from the north of the lake and previous literature. The PES profiles reveal a network of valleys, likely LGM, with relief up to c. 15-20m, that have been infilled by a suite of Holocene sediments. The valley surface is picked out as a strong reflector throughout the lake, and displays a series of valleys that are up to c. 15m deep and commonly 50-200m wide, although some of the largest valleys are 1.2km in width. Modelling of channel network incision during LGM conditions generates landscapes consistent with our field observations. The Tonle Sap valley network is infilled by sediments that show firstly fluvial and/or subaerial slope sedimentation, and then by extensive, parallel-bedded, lacustrine sedimentation. Lastly, the top c. 1m of sedimentation is marked by a distinct basal erosional surface that can be traced over much of the Tonle Sap Lake, and that is overlain by a series of parallel PES reflections. This upper sediment layer is interpreted to represent sedimentation in the Tonle Sap lake due to sediment suspension settling but after a period

  1. Sediment biomarkers elucidate the Holocene ontogeny of a shallow lake.

    Directory of Open Access Journals (Sweden)

    T E Arnold

    Full Text Available We carried out geochemical analyses on a sediment core from Lake Harris, Florida (USA to identify sources of organic matter to the sediment throughout the Holocene, and relate changes in those sources to shifts in past climate and environmental conditions. We hypothesized that the sources of organic matter changed in response to regional hydrologic shifts following de-glaciation, and to human population expansion in the state during the 20th century. Hydroclimate shifts in Florida were related to: 1 a steady rise in relative sea level and the fresh water table that began in the early Holocene, 2 wetland formation and expansion ca. 5,000 cal yrs BP, and 3 the onset of the modern El Niño (ENSO cycle ~3,000 cal yrs BP. Stratigraphic changes in sediment variables from Lake Harris reflect each of these hydroclimate periods. Early in the Holocene, Lake Harris was a marsh-like system in a relatively dry, open-prairie environment. Organic sediments deposited at that time were derived largely from terrestrial sources, as inferred from high TOC/TN ratios, a dominance of longer-chain of n-alkanes (n-C29-31, relatively negative organic carbon isotope values (δ13CTOC, and low biogenic silica concentrations. In the middle Holocene, a positive shift in δ13CTOC coincided with the onset of wetter conditions in Florida. Submerged macrophyte biomarkers (n-C21-23 dominated, and during that period bulk organic carbon isotope values were most similar to δ13C values of mid-chain-length n-alkanes. In the late Holocene, δ13CTOC values declined, CaCO3 levels decreased to trace amounts, organic carbon concentrations increased and diatom biogenic silica concentrations increased from 10 to 120 mg g-1. Around 2,900 cal yrs BP, the effects of ENSO intensified and many Florida lakes deepened to their current limnetic state. Concentrations of algal and cyanobacterial biomarkers in the Lake Harris core increased by orders of magnitude after about AD 1940, in response to

  2. Distribution and dynamics of nitrogen and microbial plankton in southern Lake Michigan during spring transition 1999-2000

    Science.gov (United States)

    Gardner, Wayne S.; Lavrentyev, Peter J.; Cavaletto, Joann F.; McCarthy, Mark J.; Eadie, Brian J.; Johengen, Thomas H.; Cotner, James B.

    2004-03-01

    Ammonium and amino acid fluxes were examined as indicators of N and microbial food web dynamics in southern Lake Michigan during spring. Either 15NH4+ or a mixture of 15N-labelled amino acids (both at 4 μM N final concentration) was added to Lake Michigan water. Net fluxes were measured over 24 h under natural light and dark conditions using deck-top incubators and compared to microbial food web characteristics. Isotope dilution experiments showed similar light and dark NH4+ regeneration rates at lake (6 versus 5 nM N h-1) and river-influenced (20 versus 24 nM N h-1) sites. Ammonium uptake rates were similar to regeneration rates in dark bottles. Dark uptake (attributed mainly to bacteria) accounted for ˜70% of total uptake (bacteria plus phytoplankton) in the light at most lake sites but only ˜30% of total uptake at river-influenced sites in or near the St. Joseph River mouth (SJRM). Cluster analysis grouped stations having zero, average, or higher than average N-cycling rates. Discriminant analysis indicated that chlorophyll concentration, oligotrich ciliate biomass, and total P concentration could explain 66% of N-cycling rate variation on average. Heterotrophic bacterial N demand was about one third of the NH4+ regeneration rate. Results suggest that, with the exception of SJRM stations, bacterial uptake and protist grazing mediated much of the N dynamics during spring transition. Since NH4+ is more available to bacteria than NO3-, regenerated NH4+ may have a strong influence on spring, lake biochemical energetics by enhancing N-poor organic matter degradation in this NO3- -replete ecosystem.

  3. Variations of alkaline phosphatase activity and P fractions in sediments of a shallow Chinese eutrophic lake (Lake Taihu)

    International Nuclear Information System (INIS)

    Zhang Tingxi; Wang Xiaorong; Jin Xiangcan

    2007-01-01

    The distribution of alkaline phosphatase activity (APA) and P fractions in sediment cores and the relationship between them were studied in a shallow Chinese freshwater lake (Lake Taihu). Sediment cores were collected from four sites, characterized by different degrees of eutrophication in June 2004. Sediment P was fractionated into Fe/Al-P, Ca-P, organic P (OP), inorganic P (IP) and total P (TP). The former two species made the largest contribution to the sediment P pool. Results show that trophic status and hydrological conditions have great impact on the APA of the sediments. The order of the APA in sediments was conjectured to be: macrophyte dominated lake > transitional lake > algal dominated lake. APA profiles follow a similar downcore decreasing trend. There was a positive relationship between the APA and the TP, IP. The multiple linear regression equation of the APA and P fractions is: APA = -97 + 0.768TP - 0.985Fe/Al-P. - Characteristics of the alkaline phosphatase activity and P fractions in sediments of different trophic status lake were studied in Lake Taihu

  4. Temperature Dependence of Apparent Respiratory Quotients and Oxygen Penetration Depth in Contrasting Lake Sediments

    Science.gov (United States)

    Sobek, Sebastian; Gudasz, Cristian; Koehler, Birgit; Tranvik, Lars J.; Bastviken, David; Morales-Pineda, María.

    2017-11-01

    Lake sediments constitute an important compartment in the carbon cycle of lakes, by burying carbon over geological timescales and by production and emission of greenhouse gases. The degradation of organic carbon (OC) in lake sediments is linked to both temperature and oxygen (O2), but the interactive nature of this regulation has not been studied in lake sediments in a quantitative way. We present the first systematic investigation of the effects of temperature on the apparent respiratory quotient (RQ, i.e., the molar ratio between carbon dioxide (CO2) production and O2 consumption) in two contrasting lake sediments. Laboratory incubations of sediment cores of a humic lake and an eutrophic lake across a 1-21°C temperature gradient over 157 days revealed that both CO2 production and O2 consumption were positively, exponentially, and similarly dependent on temperature. The apparent RQ differed significantly between the lake sediments (0.63 ± 0.26 and 0.99 ± 0.28 in the humic and the eutrophic lake, respectively; mean ± SD) and was significantly and positively related to temperature. The O2 penetration depth into the sediment varied by a factor of 2 over the 1-21°C temperature range and was significantly, negatively, and similarly related to temperature in both lake sediments. Accordingly, increasing temperature may influence the overall extent of OC degradation in lake sediments by limiting O2 supply to aerobic microbial respiration to the topmost sediment layer, resulting in a concomitant shift to less effective anaerobic degradation pathways. This suggests that temperature may represent a key controlling factor of the OC burial efficiency in lake sediments.

  5. A preliminary magnetic study of Sawa lake sediments, Southern Iraq

    Science.gov (United States)

    Ameen, Nawrass

    2016-04-01

    A preliminary magnetic study combined with chemical analyses was carried out in Sawa Lake in Al-Muthanna province, southern Iraq, about 22 km south west of Samawa city (31°18'48.80"N, 45°0'25.25"E). The lake is about 4.74 km length, 1.75 km width and 5.5 m height, it is surrounded by a salt rim which is higher than the lake water by about 2.8 m and sea water by about 18.5 m (Naqash et al., 1977 in Hassan, 2007). The lake is an elongated closed basin with no surface water available to it, it may be fed by groundwater of the Euphrates and Dammam aquifers through system of joints and cracks. This study aims to investigate the concentrations of selected heavy metals as pollutants and magnetic susceptibility (MS) and other magnetic properties of sediment samples from fifty sites collected from the bottom of the lake, the study area lies in an industrial area. The results show spatial variations of MS with mean value of about 4.58 x 10-8 m3 kg-1. Scanning electron microscopy and magnetic mineralogy parameters indicate the dominance of soft magnetic phase like magnetite and presence of hard magnetic phase like hematite. Spatial variations of MS combined with the concentrations of heavy metals suggests the efficiency of magnetic methods as effective, inexpensive and non-time consuming method to outlining the heavy metal pollution. References: Hassan W.F., 2007. The Physio-chemical characteristic of Sawa lake water in Samawa city-Iraq. Marine Mesopotamica, 22(2), 167-179.

  6. LBA-ECO LC-07 Lake Sediment Nutrient Data, Lago Calado, Brazil: 1982-1984

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set reports lake sediment texture and porosity, carbon (C), nitrogen (N), and phosphorus (P) content of surficial sediments, 210Pb-derived nutrient...

  7. LBA-ECO LC-07 Lake Sediment Nutrient Data, Lago Calado, Brazil: 1982-1984

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set reports lake sediment texture and porosity, carbon (C), nitrogen (N), and phosphorus (P) content of surficial sediments, 210Pb-derived...

  8. Relative importance of phosphorus, invasive mussels and climate for patterns in chlorophyll a and primary production in Lakes Michigan and Huron

    Science.gov (United States)

    Warner, David M.; Lesht, Barry M.

    2015-01-01

    1. Lakes Michigan and Huron, which are undergoing oligotrophication after reduction of phosphorus loading, invasion by dreissenid mussels and variation in climate, provide an opportunity to conduct large-scale evaluation of the relative importance of these changes for lake productivity. We used remote sensing, field data and an information-theoretic approach to identify factors that showed statistical relationships with observed changes in chlorophyll a (chla) and primary production (PP). 2. Spring phosphorus (TP), annual mean chla and PP have all declined significantly in both lakes since the late 1990s. Additionally, monthly mean values of chla have decreased in many but not all months, indicating altered seasonal patterns. The most striking change has been the decrease in chla concentration during the spring bloom. 3. Mean chlorophyll a concentration was 17% higher in Lake Michigan than in Lake Huron, and total production for 2008 in Lake Michigan (9.5 tg year 1 ) was 10% greater than in Lake Huron (7.8 tg year 1 ), even though Lake Michigan is slightly smaller (by 3%) than Lake Huron. Differences between the lakes in the early 1970s evidently persisted to 2008. 4. Invasive mussels influenced temporal trends in spring chla and annual primary production. However, TP had a greater effect on chla and primary production than did the mussels, and TP varied independently from them. Two climatic variables (precipitation and air temperature in the basins) influenced annual chla and annual PP, while the extent of ice cover influenced TP but not chla or primary production. Our results demonstrate that observed temporal patterns in chla and PP are the result of complex interactions of P, climate and invasive mussels.

  9. Sedimentation rates and depositional processes in Lake Superior from 210Pb geochronology

    International Nuclear Information System (INIS)

    Evans, J.E.; Johnson, T.C.; Alexander, E.C. Jr.; Lively, R.S.; Eisenreich, S.J.

    1981-01-01

    Sedimentation rates range from 0.01 to 0.32 cm/yr in 17 sediment box cores from Lake Superior, as determined by 210 Pb geochronology. Shoreline erosion and resuspension of nearshore sediments causes moderate to high (0.05-0.11 cm/yr) sedimentation rates in the western arm of Lake Superior. Sedimentation rates are very high (> 0.15 cm/yr) in marginal bays adjoining Lake Superior; and moderate to very high (0.07-0.19 cm/yr) in open lake regions adjacent to marginal bays. Resuspension of nearshore and shoal top sediments in southern and southeastern Lake Superior by storms is responsible for depositional anomalies in 210 Pb profiles corresponding to 1905, 1916-1918, and 1940 storms. Sedimentation rates are very low (0.01-0.03 cm/yr) in the central basins due to isolation from sediment sources. These data indicate that sedimentation rates and processes vary significantly in different regions of Lake Superior. The sedimentation rates provided by this study, in conjunction with previously-reported sedimentation rates, yield a better understanding of the Lake Superior depositional environment

  10. High resolution analysis of northern Patagonia lake sediments

    Science.gov (United States)

    Jarvis, S. W.; Croudace, I. W.; Langdon, P. G.; Rindby, A.

    2009-04-01

    Sediment cores covering the period from the last glacial maximum through the Holocene to the present have been collected from sites in the Chacubuco valley, southern Chile (around 47°08'S, 72°25'W, to the east of the North Patagonian Icecap). Cores were taken from five lakes and one recently dried lake bed. Short cores (0.2 to 0.5m), covering approximately the last two hundred years, were taken from all the lakes. Additionally, long sequences were obtained from one of the lakes and from the dried lake bed, the latter sequence extending back to the last glacial maximum as indicated by thick clay at the base. Each of the lakes are small-medium sized and are open systems situated at 300-1000m above sea level. The shorter cores comprise predominantly clastic gyttja but show a number of distinct changes in colour and chemical composition that suggest major environmental changes over the period of sediment accumulation. This is also reflected in variations in the loss on ignition of samples from the cores and in elemental profiles produced by scanning the cores with the Itrax micro-XRF corescanner at 200μm resolution. The long sequence from the dried lake bed has very low organic content glacial clay at the base, interpreted as last glacial maximum basal clay following determination in the field that this layer exceeded 2m in thickness. Similar sediments occur within a stratigraphically discrete section of approximately 14cm and may relate to a stadial event. The latter section also shows a drop in organic content and appears to be glacial clay incorporating some coarse sandy components indicative of detrital input from the catchment. The second long sequence, from a carbonate lake, includes two mineral layers indicating increased detrital input from the catchment. The deeper and thicker of these layers appears similar to the 14cm layer in the first long sequence, while the upper layer comprises a fine grain size indicative of rock flour and hence also of glacial

  11. Natural Environmental Hazards Reflected in High-Altitude Patagonian Lake Sediments (lake Caviahue, Argentina)

    Science.gov (United States)

    Müller, Anne; Scharf, Burkhard; von Tümpling, Wolf; Pirrung, Michael

    2009-03-01

    Two 6-m long sediment cores drilled in the two basins of Lake Caviahue give new evidence of the impact of natural hazards such as ash fallouts linked to nearby volcanic eruptions in the ecologically sensitive environment of the high-altitude region of the Argentinan Patagonian Andes. The two cores show distinct signals of changes in autochthonous productivity and terrigenous input into the lake from ash fallout as well as from river load and shore erosion. Multiproxy records of the sediments indicate whether these changes can be related to volcanic activity. High values of magnetic susceptibility in the cores reflect periods of basaltic ash fallouts during eruptions of the nearby Copahue Volcano. The southern basin is located in the prevalent direction of ash fallouts and has been affected by these volcanic inputs more intensely than the northern basin of the lake. In contrast, sedimentation and authochthonous productivity in the northern basin are strongly affected by fluvial inputs such as suspended river load and acidic stream waters.

  12. 210Pb-137Cs dating of glacial lake sediments

    International Nuclear Information System (INIS)

    Graham, I.J.; Ditchburn, R.G.; Barry, B.J.

    2004-01-01

    Sediments deposited in New Zealand lakes in the recent past provide excellent archives of local climate change via their trapped biodiversity, varve structure ad sedimentological composition. To unlock the archival information, accurate and fine-scale dating of the deposits is essential. A combination of 210 Pb and 137 Cs dating provides the most reliable and robust approach. Under favourable conditions, 210 Pb dating can provide a detailed chronology to c.120-140 y, and can be accurately calibrated by 137 Cs for the last 40 y or thereabouts. (author). 6 refs., 4 figs

  13. Unravelling Copenhagen's stride into the Anthropocene using lake sediments

    Science.gov (United States)

    Schreiber, Norman; Andersen, Thorbjørn J.; Frei, Robert; Ilsøe, Peter; Louchouarn, Patrick; Andersen, Kenneth; Funder, Svend; Rasmussen, Peter; Andresen, Camilla S.; Odgaard, Bent; Kjær, Kurt H.

    2014-05-01

    Industrialization including the effects of expanding energy consumption and metallurgy production as well as population growth and demographic pressure increased heavy-metal pollution loads progressively since the Industrial Revolution. Especially the burning of fossil fuels mobilizes heavy metals like lead and zinc on a large scale. By wet and dry deposition, these loads end up in the aquatic environment where sediments serve as sinks for these contaminations. In this study, we examine the pollution history of Copenhagen, Denmark. A sediment core was retrieved for the lake in the Botanical Gardens in central Copenhagen using a rod-operated piston corer. The water body used to be part of the old town's defence-wall system and was turned into a lake by terrain levelling in the mid 17th century. After initial X-ray fluorescence core scanning, element concentrations were determined using emission spectroscopy. The onset of gyttja accumulation in the lake is assumed to start immediately after the construction of the fortification in approximately AD 1645. An age model representing the last approximately 135 years for the uppermost 60cm was established by lead-210 and cesium-137 dating. The older part was dated via recognition of markedly increased levels of levoglucosan which are interpreted to be linked with recorded fires in Copenhagen. Similarly, two distinct layers interstratify the sediment column and mark pronounced increases of minerogenic material inflow which can be linked to known historical events. Significant pollution load increases are evident from the 1700s along with urban growth and extended combustion of carbon carriers fuels such as wood and coals. However, a more pronounced increase in lead and zinc deposition only begins by the mid-19th century. Maxima for the latter two pollutants are reached in the late 1970s followed by a reduction of emissions in accordance with stricter environmental regulations. Here, especially the phasing-out of tetraethyl

  14. Budgeting suspended sediment fluxes in tropical monsoonal watersheds with limited data: the Lake Tana basin

    Directory of Open Access Journals (Sweden)

    Zimale Fasikaw A.

    2018-03-01

    Full Text Available Soil erosion decreases soil fertility of the uplands and causes siltation of lakes and reservoirs; the lakes and reservoirs in tropical monsoonal African highlands are especially affected by sedimentation. Efforts in reducing loads by designing management practices are hampered by lack of quantitative data on the relationship of erosion in the watersheds and sediment accumulation on flood plains, lakes and reservoirs. The objective of this study is to develop a prototype quantitative method for estimating sediment budget for tropical monsoon lakes with limited observational data. Four watersheds in the Lake Tana basin were selected for this study. The Parameter Efficient Distributed (PED model that has shown to perform well in the Ethiopian highlands is used to overcome the data limitations and recreate the missing sediment fluxes. PED model parameters are calibrated using daily discharge data and the occasionally collected sediment concentration when establishing the sediment rating curves for the major rivers. The calibrated model parameters are then used to predict the sediment budget for the 1994-2009 period. Sediment retained in the lake is determined from two bathymetric surveys taken 20 years apart whereas the sediment leaving the lake is calculated based on measured discharge and observed sediment concentrations. Results show that annually on average 34 t/ha/year of sediment is removed from the gauged part of the Lake Tana watersheds. Depending on the up-scaling method from the gauged to the ungauged part, 21 to 32 t/ha/year (equivalent to 24-38 Mt/year is transported from the upland watersheds of which 46% to 65% is retained in the flood plains and 93% to 96% is trapped on the flood plains and in the lake. Thus, only 4-7% of all sediment produced in the watersheds leaves the Lake Tana Basin.

  15. Sediment radioisotope dating across a stratigraphic discontinuity in a mining-impacted lake.

    Science.gov (United States)

    McDonald, C P; Urban, N R

    2007-01-01

    Application of radioisotope sediment dating models to lakes subjected to large anthropogenic sediment inputs can be problematic. As a result of copper mining activities, Torch Lake received large volumes of sediment, the characteristics of which were dramatically different from those of the native sediment. Commonly used dating models (CIC-CSR, CRS) were applied to Torch Lake, but assumptions of these methods are violated, rendering sediment geochronologies inaccurate. A modification was made to the CRS model, utilizing a distinct horizon separating mining from post-mining sediment to differentiate between two focusing regimes. (210)Pb inventories in post-mining sediment were adjusted to correspond to those in mining-era sediment, and a sediment geochronology was established and verified using independent markers in (137)Cs accumulation profiles and core X-rays.

  16. The role of Lake Dongting in regulating the sediment budget of the Yangtze River

    Directory of Open Access Journals (Sweden)

    Shi-bao Dai

    2005-01-01

    Full Text Available Lake Dongting, the second largest freshwater lake in China and located in the middle reaches of the River Yangtze catchment, was formed at the beginning of the Holocene period by sea level rise and has varied in size with changes in local weather patterns. The sedimentation rate in Lake Dongting during the Holocene is about 50×106 m3 yr-1, or 80×106 t yr-1 (a sand bulk density of 1.6×103 kg m-3, given the sediment deposition rate as 10 mm yr-1 and the average lake size as 5000 km2. By comparing the sediment import and export, it is estimated that the sediment deposition rate of Lake Dongting was 110.6×106 t yr-1 from 1956 to 2003. Siltation and raised embankments reduced the size of the lake and its capacity to accommodate floods. The sediment delivery ratio (SDR of the middle and lower Yangtze is about 0.92 (total sediment output divided by total sediment input given that the total sediment supply into the middle and lower Yangtze is 455.1×106 t yr-1 and the total sediment discharge into the sea is 419×106 t yr-1. Therefore, if it were not for Lake Dongting, the sediment flux at Datong would be 73.6×106 t yr-1 (80×106 t yr-1×0.92 more, an increase of 27% during the Holocene and an increase of 26% to 101.75×106 t yr-1 from 1956 to 2003. Historically, Lake Dongting had a considerable influence in regulating the sediment budget of the Yangtze. However, afforestation and the construction of large dams, such as the Three Gorges Dam, reduced significantly the sediment deposition in Lake Dongting. In 2003, the completion of the Three Gorges Dam and the subsequent impoundment of water reduced the sediment input from the Yangtze and net deposition in Lake Dongting dropped to 25% and 18% of the mean values of the historic records (1956-2003. During the same period, the amount of sediment deposited in Lake Dongting was only 10% of the sediment discharge at Datong. The influence of the sediment deposited in Lake Dongting on the sediment flux to

  17. Using a Hydrodynamic and Biogeochemical Model to Investigate the Effects of Nutrient Loading from a Wastewater Treatment Plant into Lake Michigan

    Science.gov (United States)

    Khazaei, B.; Bravo, H.; Bootsma, H.

    2017-12-01

    There is clear evidence that excessive nutrient, in particular phosphorus (P), loading into Lake Michigan has produced significant problems, such as algal blooms, hypoxia, and reduced water quality. Addressing those problems requires understanding the transport and fate of P in the lake. The dominance of mixing and dispersion processes on the P transport has been demonstrated, yet recent research has shown the remarkable influence of dreissenid mussels and Cladophora on water clarity and the P budget. Since mussels and Cladophora tend to concentrate near the coastlines, nearshore-offshore P exchange is of a big importance. In this research, a computer model was developed to simulate the P cycle by incorporating the biogeochemical processes relevant to the transport of P into a 3D high-resolution hydrodynamic model. The near-bottom biogeochemical model consists of three linked modules: Cladophora, mussel, and sediment storage modules. The model was applied to the Milwaukee Metropolitan Sewerage District South Shore Wastewater Treatment Plant, between June and October of 2013 and 2015, as a case study. The plant outfall introduces a point source of P into the study domain—the nearshore zone of Lake Michigan adjacent to Milwaukee County. The model was validated against field observations of water temperature, dissolved phosphorus (DP), particulate phosphorus (PP), Cladophora biomass, and P content. The model simulations showed reasonably good agreement with field measurements. Model results showed a) different temporal patterns in 2013 and 2015, b) a larger range of fluctuations in DP than that in PP, and c) that the effects of mussels and Cladophora could explain the differences in patterns and ranges. PP concentrations showed more frequent spikes of concentration in 2013 due to resuspension events during that year because of stronger winds. The model is being applied as a management tool to test scenarios of nutrient loading to determine effluent P limits for the

  18. Sediment diffusion method improves wastewater nitrogen removal in the receiving lake sediments.

    Science.gov (United States)

    Aalto, Sanni L; Saarenheimo, Jatta; Ropponen, Janne; Juntunen, Janne; Rissanen, Antti J; Tiirola, Marja

    2018-07-01

    Sediment microbes have a great potential to transform reactive N to harmless N 2 , thus decreasing wastewater nitrogen load into aquatic ecosystems. Here, we examined if spatial allocation of the wastewater discharge by a specially constructed sediment diffuser pipe system enhanced the microbial nitrate reduction processes. Full-scale experiments were set on two Finnish lake sites, Keuruu and Petäjävesi, and effects on the nitrate removal processes were studied using the stable isotope pairing technique. All nitrate reduction rates followed nitrate concentrations, being highest at the wastewater-influenced sampling points. Complete denitrification with N 2 as an end-product was the main nitrate reduction process, indicating that the high nitrate and organic matter concentrations of wastewater did not promote nitrous oxide (N 2 O) production (truncated denitrification) or ammonification (dissimilatory nitrate reduction to ammonium; DNRA). Using 3D simulation, we demonstrated that the sediment diffusion method enhanced the contact time and amount of wastewater near the sediment surface especially in spring and in autumn, altering organic matter concentration and oxygen levels, and increasing the denitrification capacity of the sediment. We estimated that natural denitrification potentially removed 3-10% of discharged wastewater nitrate in the 33 ha study area of Keuruu, and the sediment diffusion method increased this areal denitrification capacity on average 45%. Overall, our results indicate that sediment diffusion method can supplement wastewater treatment plant (WWTP) nitrate removal without enhancing alternative harmful processes. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Early steroid sulfurization in surface sediments of a permanently stratified lake (Ace Lake, Antarctica)

    Science.gov (United States)

    Kok, Marika D.; Rijpstra, W. Irene C.; Robertson, Lisette; Volkman, John K.; Sinninghe Damstéé, Jaap S.

    2000-04-01

    Surface sediments (0-25 cm) from Ace Lake (eastern Antarctica), a saline euxinic lake, were analyzed to study the early incorporation of reduced inorganic sulfur species into organic matter. The apolar fractions were shown to consist predominantly of dimeric (poly)sulfide linked C 27-C 29 steroids. These steroid moieties were identified by GC-MS analysis of the apolar fractions after cleavage of polysulfide linkages using MeLi and MeI and after desulfurisation. The polar fractions contained the oligomeric analogues. The S-bound steroids are most likely formed by sulfur incorporation into steroidal ketones formed from Δ 5 sterols by biohydrogenation by anaerobic bacteria. The concentrations of these sulfurised steroids increased with depth in the sediment. The sulfurisation reaction is completed in 1000-3000 years. Despite a wide range of functionalised lipids present in these sediments that are potentially available for sulfurisation, there is a very strong preference for the incorporation of sulfur into steroidal compounds. A predominance of sulfurised C 27 steroids contrasted with the distribution of free sterols, which showed a strong predominance of C 29 sterols. This indicates that the incorporation of sulfur is biased towards C 27 sterols. The results demonstrate that intermolecular sulfurisation of organic matter can occur in surface sediments at low temperatures and in the absence of light.

  20. Vitality of aquatic plants and microbial activity of sediment in an oligotrophic lake (Lake Bohinj, Slovenia

    Directory of Open Access Journals (Sweden)

    Tatjana SIMČIČ

    2011-08-01

    Full Text Available The vitality of eight macrophyte species and the microbial activity of sediment in an oligotrophic lake (Lake Bohinj, Slovenia were studied via the terminal electron transport system (ETS activity of mitochondria. The levels of ETS activity of vascular plants were as follows: Ranunculus circinatus, Myriohpyllum spicatum, Potamogeton alpinus, P. perfoliatus, P. lucens. Fontinalis antipyretica exhibited the highest ETS activity of the non-vascular plants, followed by charales Chara delicatula and C. aspera. High values enable R. circinatus, an amphibious species with rapid growth, to survive under conditions in which the water level changes throughout the season. M. spicatum, a species with broad ecological tolerance, also exhibited high ETS activity. The ETS activity of the microbial community in sediment was affected by temperature and/or the amount and origin of the organic matter. A positive correlation between the ETS activity of the sediment and that of M. spicatum and R. circinatus was measured, while negative correlations or no correlation were observed for mosses and macroalgae. The high ETS activity in sediment indicates rapid mineralization of organic matter and, in turn, sufficient nutrients for growth of macrophytes.

  1. Measuring groundwater transport through lake sediments by advection and diffusion

    International Nuclear Information System (INIS)

    Cornett, R.J.; Risto, B.A.; Lee, D.R.

    1989-08-01

    A method for estimating low rates of groundwater inflow and outflow through the bottom sediments of surface waters was developed and tested. A one-dimensional advection-diffusion model was fitted to measured pore water profiles of two nonreactive solutes, tritiated water and chloride, and the advection rate was calculated by a nonlinear least squares technique. Using 3 H profiles measured 0-0.5 m below the sediment-water interface, rates of groundwater advection into a lake through interbedded sands and gyttja were estimated to be about 1.0 m/year. In midlake locations underlain by soft organic gyttja, rates of advection were much lower (<0.1 m/year). Knowledge of the rate and direction of groundwater flow substantially altered the interpretation of pore water profiles within the sediments and the fluxes of solutes. This technique can be used to estimate flow rates less than 2 m/annum with minimal disturbance, without enclosing the sediments in a container, in a diversity of systems. (author)

  2. Flood-Induced Surface Blooms Alter Deep Chlorophyll Maxima Community Structure in Lake Michigan.

    Science.gov (United States)

    Aguilar, C.; Cuhel, R. L.; Seline, L.

    2008-12-01

    Watershed-wide floods can bring increased nutrients and phytoplankton to receiving waters. This input can alter physical, chemical and phytoplankton community structure in a major way. Phytoplankton species composition and size distribution are key factors in their use as ecological indicators. Since 2003, phytoplankton communities in Lake Michigan have shifted from diatom and big cell (>10μm)- dominated to small cell picocyanobacteria-dominated phytoplankton (Quagga Mussels, dampened seasonal cycling of silicate indicated a basin-wide reduction of diatom production, and unicellular Cyanobacteria became dominant in deep chlorophyll maximum (DCM) zones. In the DCM, Synechococcus-like cells reached populations of at least 210,000 cells/ml. DCM chlorophyll (chl) remained similar (3-4μg/l) but late summer species composition changed dramatically to mostly 10μm fraction increased from previous years, and over 75% of the particulate Si was also in this size fraction. Because of the rapid sinking of diatoms during calm weather of late June-early July of 2008, particulate Si did not reach high values in surfaces waters (ca. 1.5μM) but remained at a consistently higher level than in 2007. Sinking of diatoms from the surface depleted chl in a progression from inshore to offshore during July 2008. In July surface chl was higher 40-70 km offshore than in the coastal zone. Surface phytoplankton waxed and waned in population density as if a wave or lens moved continuously further offshore, with sinking cells depleting the surface algae following behind the crest. In the wake, strong DCM populations with higher chl and particulate Si accumulated in the 30-45m zone at the bottom of the thermocline. However, in 2008 DCM zones, picocyanobacteria attained only 70,000 cells/mL, one-third of the same dates in 2007. The ratio of chlorophyll per Synechococcus cell in 2008 was about 5-fold higher than in 2007, corroborating microscopic observations of lowered picoplanktonic abundance

  3. Modern sedimentation patterns in Lake El'gygytgyn, NE Russia, derived from surface sediment and inlet streams samples

    Directory of Open Access Journals (Sweden)

    V. Wennrich

    2013-01-01

    Full Text Available Lake El'gygytgyn/NE Russia holds a continuous 3.58 Ma sediment record, which is regarded as the most long-lasting climate archive of the terrestrial Arctic. Based on multi-proxy geochemical, mineralogical, and granulometric analyses of surface sediment, inlet stream and bedrock samples, supplemented by statistical methods, major processes influencing the modern sedimentation in the lake were investigated. Grain-size parameters and chemical elements linked to the input of feldspars from acidic bedrock indicate a wind-induced two-cell current system as major driver of sediment transport and accumulation processes in Lake El'gygytgyn. The distribution of mafic rock related elements in the sediment on the lake floor can be traced back to the input of weathering products of basaltic rocks in the catchment. Obvious similarities in the spatial variability of manganese and heavy metals indicate sorption or co-precipitation of these elements with Fe and Mn hydroxides and oxides. But the similar distribution of organic matter and clay contents might also point to a fixation to organic components and clay minerals. An enrichment of mercury in the inlet streams might be indicative of neotectonic activity around the lake. The results of this study add to the fundamental knowledge of the modern lake processes of Lake El'gygytgyn and its lake-catchment interactions, and thus, yield crucial insights for the interpretation of paleo-data from this unique archive.

  4. Lake-sediment evidence for the date of deglaciation of the Hidden Lake area, Kenai Peninsula, Alaska

    Science.gov (United States)

    Rymer, Michael J.; Sims, John D.

    1982-06-01

    An abrupt environmental change is reflected in a core from Hidden Lake, Alaska, by differences in sediment type, chlorite crystallinity, and content of organic carbon and water of the sediments. This abrupt change in the sedimentary record occurred about 14,500 14C yr ago and probably marks the time of recession of the glacier from the Hidden Lake drainage basin. Deglaciation of the area was then underway, and rock flour was being deposited in the lake. After recession of the glacier from the Hidden Lake drainage basin, rock flour was no longer introduced, and organic-matter content of the sediment increased. By the dating of these changes in sediment type, we show that retreat of glaciers in this area took place significantly earlier than previously estimated; this agrees with the timing of retreat of alpine glaciers elsewhere in western North America.

  5. Population biology of alewives, Alosa pseudoharengus, in Lake Michigan, 1949-70

    Science.gov (United States)

    Brown, Edward H.

    1972-01-01

    Alewives were unknown in Lake Michigan before 1949, but became extremely abundant in the 1960s and soon exceeded the carrying capacity of the lake. In 1967 they were decimated by a lakewide mass mortality, and have since been less abundant as 'adults' (a?Y 120 mm long), although numerous young were produced in 1969-70 and the adult population appeared to be gradually increasing. Alewives were studied intensively during 1962-70 on the basis of collections made primarily with bottom trawls. Principal considerations in the population study include effects of seasonal changes in distribution on length composition of young and adults, sex and maturity in relation to size and age at recruitment into adult stocks, and changes in age, growth, condition, and population structure that accompanied the drastic changes in abundance. A substantial increase in the age of adults in the bottom stocks and on the spawning grounds was among the important population changes after the 1967 die-off. Growth of older adults also increased appreciably immediately after the die-off, and a sharp increase in average weight (16-26%) over a standard range of lengths was maintained in 1968-70. Selective depletion of zooplankton by alewives was evidence that overabundance decreased the food supply, depressed growth, and caused the poor condition that made alewives vulnerable to excessive mortality in 1967. Although poor condition in fall undoubtedly increased winter and spring mortality in the mid-1960s, alewives apparently were stressed by below-average temperature in the winter of 1969-70, and experiences a light die-off through May 1970 despite their good condition and relatively low population density the preceding fall. The population upsurge that preceded the 1967 die-off was reflected by a fivefold increase of adults in the fall index catch (in trawls) from 1962 to 1965 and 1966. The index catch then dropped 70% in fall 1967. Mortality among the 1960-64 year-classes, as represented by

  6. Emerging technologies and approaches to minimize discharges into Lake Michigan Phase 2, Module 3 report.

    Energy Technology Data Exchange (ETDEWEB)

    Negri, M. C.; Gillenwater, P.; Urgun Demirtas, M. (Energy Systems)

    2011-05-11

    Purdue University Calumet (Purdue) and Argonne National Laboratory (Argonne) have conducted an independent study to identify deployable technologies that could help the BP Whiting Refinery, and other petroleum refineries, meet future wastewater discharge limits. This study has been funded by BP. Each organization tested a subset of the target technologies and retains sole responsibility for its respective test design and implementation, quality assurance and control, test results obtained from each of the technologies, and corresponding conclusions and recommendations. This project was divided in two phases and modules. This report summarizes the work conducted by Argonne in Phase II Module 3 (Bench Scale Testing). Other Modules are discussed elsewhere (Emerging Technologies and Approaches to Minimize Discharges into Lake Michigan, Phase 2, Modules 1-3 Report, April 2011, prepared for BP Americas by the Argonne - Purdue Task Force). The goal of this project was to identify and assess available and emerging wastewater treatment technologies for removing mercury and vanadium from the Whiting Refinery wastewater and to conduct bench-scale tests to provide comparable, transparent, and uniform results across the broad range of technologies tested. After the bench-scale testing phase, a previously developed decision matrix was refined and applied by Argonne to process and review test data to estimate and compare the preliminary performance, engineering configuration, preliminary cost, energy usage, and waste generation of technologies that were shown to be able to remove Hg and/or V to below the target limit at the bench scale. The data were used as the basis to identify the best candidates for further testing at the bench or pilot scale on a slip stream of effluent to lake (ETL) or clarifier effluent (CE) at the Whiting Refinery to determine whether future limits could be met and to generate other pertinent data for scale-up and sustainability evaluation. As a result of

  7. Potential nitrate removal in a coastal freshwater sediment (Haringvliet Lake, The Netherlands) and response to salinization

    NARCIS (Netherlands)

    Laverman, A.M.; Canavan, R.W.; Slomp, C.P.; Van Cappellen, P.

    2007-01-01

    Nitrogen transformations and their response to salinization were studied in bottom sediment of a coastal freshwater lake (Haringvliet Lake, The Netherlands). The lake was formed as the result of a river impoundment along the south-western coast of the Netherlands, and is currently targeted for

  8. Microbial communities and fecal indicator bacteria associated with Cladophora mats on beach sites along Lake Michigan shores.

    Science.gov (United States)

    Olapade, Ola A; Depas, Morgan M; Jensen, Erika T; McLellan, Sandra L

    2006-03-01

    A high biomasses of Cladophora, a filamentous green alga, is found mainly during the summer along the shores of Lake Michigan. In this study, the abundance and persistence of the fecal indicator bacterium Escherichia coli and sulfate-reducing bacteria (SRB) on Cladophora mats collected at Lake Michigan beaches were evaluated using both culture-based and molecular analyses. Additionally, 16S rRNA gene cloning and sequencing were used to examine the bacterial community composition. Overall, E. coli was detected in all 63 samples obtained from 11 sites, and the average levels at most beaches ranged from 2,700 CFU/100 g (wet weight) of Cladophora to 7,500 CFU/100 g of Cladophora. However, three beaches were found to have site average E. coli densities of 12,800, 21,130, and 27,950 CFU/100 g of Cladophora. The E. coli levels in the lake water collected at the same time from these three sites were less than the recommended U.S. Environmental Protection Agency limit, 235 CFU/100 ml. E. coli also persisted on Cladophora mats in microcosms at room temperature for more than 7 days, and in some experiments it persisted for as long as 28 days. The SRB densities on Cladophora mats were relatively high, ranging from 4.4x10(6) cells/g (6.64 log CFU/g) to 5.73x10(6) cells/g (6.76 log CFU/g) and accounting for between 20% and 27% of the total bacterial counts. Partial sequences of the 16S rRNA gene clones revealed a phylogenetically diverse community, in which the Cytophaga-Flavobacterium-Bacteroides cluster and the low-G+C-content gram-positive bacteria were the dominant organisms, accounting for 40% and 12.8%, respectively, of the total clone library. These results further reveal the potential public health and ecological significance of Cladophora mats that are commonly found along the shoreline of Lake Michigan, especially with regard to the potential to harbor microorganisms associated with fecal pollution and odor-causing bacteria.

  9. Suspended-sediment budget, flow distribution, and lake circulation for the Fox Chain of Lakes in Lake and McHenry Counties, Illinois, 1997-99

    Science.gov (United States)

    Schrader, David L.; Holmes, Robert R.

    2000-01-01

    The Fox Chain of Lakes is a glacial lake system in McHenry and Lake Counties in northern Illinois and southern Wisconsin. Sedimentation and nutrient overloading have occurred in the lake system since the first dam was built (1907) in McHenry to raise water levels in the lake system. Using data collected from December 1, 1997, to June 1, 1999, suspended-sediment budgets were constructed for the most upstream lake in the system, Grass Lake, and for the lakes downstream from Grass Lake. A total of 64,900 tons of suspended sediment entered Grass Lake during the study, whereas a total of 70,600 tons of suspended sediment exited the lake, indicating a net scour of 5,700 tons of sediment. A total of 44,100 tons of suspended sediment was measured exiting the Fox Chain of Lakes at Johnsburg, whereas 85,600 tons entered the system downstream from Grass Lake. These suspended-sediment loads indicate a net deposition of 41,500 tons downstream from Grass Lake, which represents a trapping efficiency of 48.5 percent. A large amount of recreational boating takes place on the Fox Chain of Lakes during summer months, and suspended-sediment load was observed to rise from 110 tons per day to 339 tons per day during the 1999 Memorial Day weekend (May 26 ?31, 1999). Presumably, this rise was the result of the boating traffic because no other hydrologic event is known to have occurred that might have caused the rise. This study covers a relatively short period and may not represent the long-term processes of the Fox Chain of Lakes system, although the sediment transport was probably higher than an average year. The bed sediments found on the bottom of the lakes are composed of mainly fine particles in the silt-clay range. The Grass Lake sediments were characterized as black peat with an organic content of between 9 and 18 percent, and the median particle size ranged from 0.000811 to 0.0013976 inches. Other bed material samples were collected at streamflow-gaging stations on the

  10. Ferromagnetic response of a sediment record from Lake Soppensee

    Science.gov (United States)

    Kind, J.; García-Rubio, I.; Gehring, A. U.

    2012-12-01

    Environmental magnetism uses the spatial and temporal occurrence of magnetic carriers as diagnostic tools to detect environmental changes. Concentration, composition, grain size, and configuration of magnetite can be indicative of the origin of this magnetic carrier. In order to reconstruct the development of Lake Soppensee (Central Switzerland) since the late Pleistocene, a detailed ferromagnetic resonance (FMR) spectroscopy analysis was applied. FMR is a powerful tool to probe the magnetic properties of ferrimagnetic materials. Sediments from Lake Soppensee were analyzed in order to deduce different processes causing the formation of magnetite and its preservation. Based on the occurrence of magnetite, the sediment record can be subdivided into three stages. The first stage, attributed to the deglaciation contains superparamagnetic (SP) magnetite that is detected by the low-temperature FMR analysis. The simultaneous occurrence of SP magnetite in sediments with predominant hematite is interpreted as magnetite formation in reducing interstitial voids within a prevailing oxic environment. The second stage, assigned to the Bølling/Allerød - Younger Dryas period contains stable single domain (SSD) magnetite in varying concentrations. During the Bølling/Allerød denser vegetation cover led to an increase of organic matter in the depositional environment, which accelerated the microbial activity and the consumption of oxygen and the enhanced formation of SSD magnetite. An opposite trend is found for the cold Younger Dryas period. The third stage during the fairly stable Holocene exhibits the formation of SSD magnetite solely. Even though no drastic climatic changes are documented throughout the Holocene, the magnetite content varies considerably. In sediments with high magnetite content, dispersed magnetite particles and magnetite in chain-like configuration were detected by anisotropy traits inferred from the FMR spectra. This configuration provides clear evidence

  11. Toxicities and risk assessment of heavy metals in sediments of Taihu Lake, China, based on sediment quality guidelines.

    Science.gov (United States)

    Zhang, Yanfeng; Han, Yuwei; Yang, Jinxi; Zhu, Lingyan; Zhong, Wenjue

    2017-12-01

    The occurrence, toxicities, and ecological risks of five heavy metals (Pb, Cu, Cd, Zn and Ni) in the sediment of Taihu Lake were investigated in this study. To evaluate the toxicities caused by the heavy metals, the toxicities induced by organic contaminants and ammonia in the sediments were screened out with activated carbon and zeolite. The toxicities of heavy metals in sediments were tested with benthic invertebrates (tubificid and chironomid). The correlations between toxicity of sediment and the sediment quality guidelines (SQGs) derived previously were evaluated. There were significant correlations (pheavy metals based on SQGs, indicating that threshold effect level (TEL) and probable effect level (PEL) were reliable to predict the toxicities of heavy metals in the sediments of Taihu Lake. By contrast, the method based on acid volatile sulfides (AVS) and simultaneously extracted metals (SEM), such as ∑SEM/AVS and ∑SEM-AVS, did not show correlations with the toxicities. Moreover, the predictive ability of SQGs was confirmed by a total predicting accuracy of 77%. Ecological risk assessment based on TELs and PELs showed that the contaminations of Pb, Cu, Cd and Zn in the sediments of Taihu Lake were at relatively low or medium levels. The risks caused by heavy metals in the sediments of northern bay of the lake, which received more wastewater discharge from upper stream, were higher than other area of the lake. Copyright © 2017. Published by Elsevier B.V.

  12. Heavy metals in bottom sediments of Lake Umbozero in Murmansk Region, Russia

    DEFF Research Database (Denmark)

    Jernström, Jussi; Lehto, J.; Dauvalter, A.

    2010-01-01

    Sediment cores collected from different locations of Lake Umbozero were studied with respect to concentration and mobility of trace and heavy metals Co, Cu, Fe, Mn, Ni, Pb, U, and Zn. Lake Umbozero is the second largest lake in the Murmansk Region and subjected to contamination by air......-borne emissions and river transportation from the nearby metallurgical and mining industries. Unlike its neighboring, more industry-prone Lake Imandra, Lake Umbozero is relatively unexplored with respect to its state of pollution. In our study, metal distribution in sediments was found to vary with respect...... in lakes of Kola Peninsula located further off from industrial pollutant sources. An exception was Pb the concentration of which was at the same level as in Lake Imandra, probably due to long-distance transport. Sediment layers were subjected to four-step sequential extraction procedure to reveal the metal...

  13. Rare elements in sediments of brine lakes of Sasykkul'skaya depression (East Pamir)

    International Nuclear Information System (INIS)

    Volkova, N.I.; Pachadzhanov, D.N.; Ozerov, A.M.; AN Uzbekskoj SSR, Tashkent

    1993-01-01

    Contents of wide range of chemical elements have been determined for the first time in chemical-terigenous sediments of brine lakes of Sasykkul'skaya depression. It has been shown that the global evolution of sedimentation process in salt-forming basin of Sasykkul'skaya depression resulted in pronounced separation of chemical elements to accumulating and dispersing in lake sediments ones from one hand and to the elements with halophobe and halophile properties-from another. It has been stated that lake sediments are enriched in B, Mo, W, U, Th

  14. Temporal and Spatial Dynamics of Sediment Anaerobic Ammonium Oxidation (Anammox) Bacteria in Freshwater Lakes.

    Science.gov (United States)

    Yang, Yuyin; Dai, Yu; Li, Ningning; Li, Bingxin; Xie, Shuguang; Liu, Yong

    2017-02-01

    Anaerobic ammonium-oxidizing (anammox) process can play an important role in freshwater nitrogen cycle. However, the distribution of anammox bacteria in freshwater lake and the associated environmental factors remain essentially unclear. The present study investigated the temporal and spatial dynamics of sediment anammox bacterial populations in eutrotrophic Dianchi Lake and mesotrophic Erhai Lake on the Yunnan Plateau (southwestern China). The remarkable spatial change of anammox bacterial abundance was found in Dianchi Lake, while the relatively slight spatial shift occurred in Erhai Lake. Dianchi Lake had greater anammox bacterial abundance than Erhai Lake. In both Dianchi Lake and Erhai Lake, anammox bacteria were much more abundant in summer than in spring. Anammox bacterial community richness, diversity, and structure in these two freshwater lakes were subjected to temporal and spatial variations. Sediment anammox bacterial communities in Dianchi Lake and Erhai Lake were dominated by Candidatus Brocadia and a novel phylotype followed by Candidatus Kuenenia; however, these two lakes had distinct anammox bacterial community structure. In addition, trophic status determined sediment anammox bacterial community structure.

  15. Gut content analysis of Lake Michigan waterbirds in years with avian botulism type E mortality, 2010–2012

    Science.gov (United States)

    Essian, David A.; Chipault, Jennifer G.; Lafrancois, Brenda M.; Leonard, Jill B.K.

    2016-01-01

    Waterbird die-offs caused by Clostridium botulinum neurotoxin type E (BoNT/E) have occurred sporadically in the Great Lakes since the late 1960s, with a recent pulse starting in the late 1990s. In recent die-offs, round gobies (Neogobius melanostomus) have been implicated as vectors for the transfer of BoNT/E to fish-eating birds due to the round goby invasion history and their importance as prey. Dreissenid mussels (Dreissena spp.) are also potentially involved in BoNT/E transmission to birds and round gobies. We examined gut contents of waterbirds collected in Lake Michigan during die-offs in 2010–2012, and the gut contents of culled, presumably BoNT/E-free double-crested cormorants (Phalacrocorax auritus). Round gobies were found in 86% of the BoNT/E-positive individuals, 84% of the BoNT/E-negative birds, and 94% of the BoNT/E-free cormorants examined. Double-crested cormorants, ring-billed gulls (Larus delewarensis), and common loons (Gavia immer) consumed larger-sized round gobies than horned and red-necked grebes (Podiceps auritus and Podiceps grisegena), white-winged scoters (Melanitta deglandi), and long-tailed ducks (Clangula hymealis). Other common prey included dreissenid mussels, terrestrial insects, and alewives (Alosa pseudoharengus). Our data emphasize the importance of round gobies and mussels in diets of Lake Michigan waterbirds and suggest they may play a role in the transfer of BoNT/E to waterbirds; however, round gobies and mussels were found in BoNT/E-positive, -negative, and -free individuals, suggesting that other factors, such as alternative trophic pathways for toxin transfer, bird migratory timing and feeding locations, prey behavior, and individual physiological differences across birds may affect the likelihood that a bird will succumb to BoNT/E intoxication.

  16. 33 CFR 165.929 - Safety Zones; Annual events requiring safety zones in the Captain of the Port Lake Michigan zone.

    Science.gov (United States)

    2010-07-01

    ... weather, then this section will be enforced July 4; 9 p.m. to 11 p.m. (15) Taste of Chicago Fireworks; Chicago IL—(i) Location. All waters of Monroe Harbor and all waters of Lake Michigan bounded by a line... 11 p.m. If the July 4 fire works are cancelled due to inclement weather, then this section will be...

  17. 33 CFR 165.T09-0166 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety Zone, Brandon Road Lock... Areas Ninth Coast Guard District § 165.T09-0166 Safety Zone, Brandon Road Lock and Dam to Lake Michigan.... waters of the Des Plaines River located between mile marker 286.0 (Brandon Road Lock and Dam) and mile...

  18. Coastal Change Analysis Program (C-CAP) Great Lakes; Michigan 1996-2001 era land cover change analysis (NODC Accession 0042189)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is a change analysis of 1996-era C-CAP land cover and 2001-era C-CAP land cover for the State of Michigan, in the Great Lakes Region of the U.S. This...

  19. Organic sedimentation in modern lacustrine systems: A case study from Lake Malawi, East Africa

    Science.gov (United States)

    Ellis, Geoffrey S.; Barry J. Katz,; Christopher A. Scholz,; Peter K. Swart,

    2015-01-01

    This study examines the relationship between depositional environment and sedimentary organic geochemistry in Lake Malawi, East Africa, and evaluates the relative significance of the various processes that control sedimentary organic matter (OM) in lacustrine systems. Total organic carbon (TOC) concentrations in recent sediments from Lake Malawi range from 0.01 to 8.80 wt% and average 2.83 wt% for surface sediments and 2.35 wt% for shallow core sediments. Hydrogen index (HI) values as determined by Rock-Eval pyrolysis range from 0 to 756 mg HC g−1 TOC and average 205 mg HC g−1 TOC for surface sediments and 228 mg HC g−1 TOC for shallow core samples. On average, variations in primary productivity throughout the lake may account for ~33% of the TOC content in Lake Malawi sediments (as much as 1 wt% TOC), and have little or no impact on sedimentary HI values. Similarly, ~33% to 66% of the variation in TOC content in Lake Malawi sediments appears to be controlled by anoxic preservation of OM (~1–2 wt% TOC), although some component of the water depth–TOC relationship may be due to physical sediment transport processes. Furthermore, anoxic preservation has a minimal effect on HI values in Lake Malawi sediments. Dilution of OM by inorganic sediment may account for ~16% of variability in TOC content in Lake Malawi sediments (~0.5 wt% TOC). The effect of inputs of terrestrial sediment on the organic character of surface sediments in these lakes is highly variable, and appears to be more closely related to the local depositional environment than the regional flux of terrestrial OM. Total nitrogen and TOC content in surface sediments collected throughout the lake are found to be highly correlated (r2 = 0.95), indicating a well-homogenized source of OM to the lake bottom. The recurring suspension and deposition of terrestrial sediment may account for significant amounts of OM deposited in offshore regions of the lake. This process effectively separates denser

  20. Sedimentation influx and volcanic interactions in the Fuji Five Lakes: implications for paleoseismological records

    Science.gov (United States)

    Lamair, Laura; Hubert-Ferrari, Aurélia; Yamamoto, Shinya; El Ouahabi, Meriam; Garrett, Ed; Shishikura, Masanobu; Schmidt, Sabine; Boes, Evelien; Obrochta, Stephen; Nakamura, Atsunori; Miyairi, Yosuke; Yokoyama, Yusuke; De Batist, Marc; Heyvaert, Vanessa M. A.

    2017-04-01

    The Fuji Fives Lakes are located at the foot of Mount Fuji volcano close to the triple junction, where the North American Plate, the Eurasian plate and the Philippine Sea Plate meet. These lakes are ideally situated to study Mount Fuji volcanism and the interaction between volcanism, changes in lake sedimentation rates and the ability of lakes to record paleoearthquakes. Here, we present newly acquired geological data of Lake Yamanaka and Lake Motosu, including seismic reflection profiles, gravity and piston cores. These two lakes and their respective watersheds were affected by several eruptions of Mount Fuji. Lake Yamanaka, a very shallow lake (max. depth 14 m), was heavily impacted by the scoria fall-out of the A.D. 1707 Hoei eruption of Mount Fuji. A detailed investigation of the effect of the Hoei eruption was conducted on short gravity cores, using high resolution XRD, C/N and 210Pb/137Cs analyses. The preliminary results suggest that the sedimentation rate of Lake Yamanaka drastically reduced after the Hoei eruption, followed by an increase until the present day. Similarly, lacustrine sedimentation in Lake Motosu (max. depth 122 m) was disturbed by Mount Fuji volcanism at a larger scale. The watershed of Lake Motosu was impacted by several lava flows and scoria cones. For example, the Omuro scoria cone reduced the catchment size of Lake Motosu and modified its physiography. The related scoria fall out covered an extensive part of the lake catchment and reduced terrigenous sedimentary influx to Lake Motosu. Within the deep basin of Lake Motosu, seismic reflection data shows two different periods that are distinguished by a major change in the dominant sedimentary processes. During the first period, sublacustrine landslides and turbidity currents were the dominant sedimentation processes. During the second one, the seismic stratigraphy evidences only deposition of numerous turbidites interrupting the hemipelagic sedimentation. Changes in sedimentary processes

  1. Characterization of water and lake sediments in Laguna de Bay

    International Nuclear Information System (INIS)

    San Diego, Cherry Ann; Francisco, Pattrice Armynne; Navoa, Joshua Antonio; Johnson, Bryan; Dave, Harshil; Cryer, Karl; Panemanglor, Rajeev; Rama, Mariecar; Sucgang, Raymond J.

    2011-01-01

    In this work we studied elemental distributions of trace elements, dissolved oxygen and microbiological allotment (total plate count, Coliform, and E. coli) in sediment and surface water from 3 sites in Laguna de Bay. The measured parameters were associated with the quality of the water and to anthropogenic and geogenic processes taking place in the lake. In all cases sediment samples were collected and analyzed for elemental composition using an X-ray fluorescence technique. Water samples were collected and analyzed for nitrate, chloride, and sulfate ions using selective electrodes. Bicarbonate ions in the lake water were determined by titration. The microbial load (total plate count, total coliform and E,. Coli) were determined using Simplate. Field parameters such as pH and conductivity were likewise measured. Preliminary assumptions suggest that proximity to anthropogenic sources has substantially contributed to the combined loads of major ions pollution in the lake. Laguna de Bay is classified as Class C (DENR Administrative Order No. 34). For all the sites, the conductivity of the water were considerably elevated, which ranged from 929 to 933 uS/cm; Site 1 water exceeded the permissible range for pH for Class C water which is 6.5 to 8.5 for the support and rearing of fish. None of the lake waters exceeded the limits for the ions, chloride (set at 350 mg/L) and nitrate (set at 10 mg/L), for Class C water criteria. All the sites meet the dissolved oxygen, DO, criterion for Class C waters which is set at 5 mg/L. In terms of microbiological load, Site 1 had the least most probable number per ml of water, MPN/ml: total plate count (6720), Coliform (less that detection limit) and E. coli (less than LLD); Site 3 was the most contaminated: total plate count (greater than 70,000), Coliform(48768) and E. Coli (23808). X-ray fluorescence analyses of sediments allowed the determination of elements Na, Mg, Al, P, Si, Cl, K. Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Br, Rb

  2. Water-Sediment Partition of Polycyclic Aromatic Hydrocarbons (PAHs) in Nansi Lake

    Science.gov (United States)

    Zhang, Guizhai; Diao, Youjiang

    2018-06-01

    Based on field data of polycyclic aromatic hydrocarbons (PAHs) in water and sediment in Nansi Lake. The concentrations and the partitioning characteristic of PAHs in the water and sediment were studied. The lgKd of high molecular weight PAHs were higher than the low molecular weight PAHs. The most of PAHs Kd values were negligible correlated with TOC, soluble salt, clay and pH of the sediment in Nansi Lake.

  3. Sources of mercury in sediments, water, and fish of the lakes of Whatcom County, Washington

    Science.gov (United States)

    Paulson, Anthony J.

    2004-01-01

    Concerns about mercury (Hg) contamination in Lake Whatcom, Washington, were raised in the late 1990s after a watershed protection survey reported elevated concentrations of Hg in smallmouth bass. The U.S. Geological Survey, the Whatcom County Health Department, and the Washington State Department of Ecology (Ecology) cooperated to develop a study to review existing data and collect new data that would lead to a better understanding of Hg deposition to Lake Whatcom and other lakes in Whatcom County, Washington. A simple atmospheric deposition model was developed that allowed comparisons of the deposition of Hg to the surfaces of each lake. Estimates of Hg deposition derived from the model indicated that the most significant deposition of Hg would have occurred to the lakes north of the City of Bellingham. These lakes were in the primary wind pattern of two municipal waste incinerators. Of all the lakes examined, basin 1 of Lake Whatcom would have been most affected by the Hg emissions from the chlor-alkali plant and the municipal sewage-sludge incinerator in the City of Bellingham. The length-adjusted concentrations of Hg in largemouth and smallmouth bass were not related to estimated deposition rates of Hg to the lakes from local atmospheric sources. Total Hg concentrations in the surface sediments of Lake Whatcom are affected by the sedimentation of fine-grained particles, whereas organic carbon regulates the concentration of methyl-Hg in the surface sediments of the lake. Hg concentrations in dated sediment core samples indicate that increases in Hg sedimentation were largest during the first half of the 20th century. Increases in Hg sedimentation were smaller after the chlor-alkali plant and the incinerators began operating between 1964 and 1984. Analysis of sediments recently deposited in basin 1 of Lake Whatcom, Lake Terrell, and Lake Samish indicates a decrease in Hg sedimentation. Concentrations of Hg in Seattle precipitation and in tributary waters were

  4. Assessing the natural recovery of a lake contaminated with Hg using estimated recovery rates determined by sediment chronologies

    International Nuclear Information System (INIS)

    Parsons, Matthew J.; Long, David T.; Yohn, Sharon S.

    2010-01-01

    Research highlights: → Identifying the cause of Hg contamination via correlations to iron ore production. → Using Hg:Al ratio to show changes in pathway from a point to non-point source. → Overcoming challenges to age determination using event-based dating. → Using sediment cores to estimate recovery rates and identify arrested recovery. - Abstract: Deer Lake is an impoundment located near Ishpeming, Michigan, USA. Iron mining assay laboratories located in Ishpeming disposed of Hg salts to the city sewer whose outfall was located along an inlet to Deer Lake. An effort to remediate the system in the mid 1980s which consisted of drawing down water in the impoundment in order to volatize Hg from the sediments did not result in recovery of the system. Since the mid 1990s, the remediation strategy has been to allow the continual burial of the contaminated sediments, i.e., natural recovery. The goal of this study was to assess the effectiveness of this strategy. This was accomplished by investigating State of the system in terms of its recovery and estimating the time frame for recovery. Sediment cores were collected in 2000 to determine historical trends in accumulation rates and concentrations of Hg and other metals. Sedimentation rates and sediment ages were estimated using 210 Pb. Event-based dating (e.g., peak of 137 Cs in 1963) was used to supplement 210 Pb data due to non-monotonic features in the 210 Pb profile and activities that were not at supported levels at the base of the core. Selected results are that: (1) drawdown significantly influenced sedimentation patterns causing slopes for 210 Pb profiles that reflected the influx of older sediment, (2) periods of Fe production correlate to Hg loading indicating the point source for contamination, a relationship not previously identified, (3) Hg:Al ratios indicate a recent change to a watershed pathway for Hg loading and (4) Hg concentrations had decreased from their peak, remain elevated, and were

  5. Assessing the natural recovery of a lake contaminated with Hg using estimated recovery rates determined by sediment chronologies

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, Matthew J. [Michigan State University, Department of Geological Sciences, 206 Natural Science, East Lansing, MI 48824 (United States); Long, David T., E-mail: long@msu.edu [Michigan State University, Department of Geological Sciences, 206 Natural Science, East Lansing, MI 48824 (United States); Yohn, Sharon S. [Juniata College, Raystown Field Station, Brumbaugh Academic Center, Huntingdon, PA 16652 (United States)

    2010-11-15

    Research highlights: {yields} Identifying the cause of Hg contamination via correlations to iron ore production. {yields} Using Hg:Al ratio to show changes in pathway from a point to non-point source. {yields} Overcoming challenges to age determination using event-based dating. {yields} Using sediment cores to estimate recovery rates and identify arrested recovery. - Abstract: Deer Lake is an impoundment located near Ishpeming, Michigan, USA. Iron mining assay laboratories located in Ishpeming disposed of Hg salts to the city sewer whose outfall was located along an inlet to Deer Lake. An effort to remediate the system in the mid 1980s which consisted of drawing down water in the impoundment in order to volatize Hg from the sediments did not result in recovery of the system. Since the mid 1990s, the remediation strategy has been to allow the continual burial of the contaminated sediments, i.e., natural recovery. The goal of this study was to assess the effectiveness of this strategy. This was accomplished by investigating State of the system in terms of its recovery and estimating the time frame for recovery. Sediment cores were collected in 2000 to determine historical trends in accumulation rates and concentrations of Hg and other metals. Sedimentation rates and sediment ages were estimated using {sup 210}Pb. Event-based dating (e.g., peak of {sup 137}Cs in 1963) was used to supplement {sup 210}Pb data due to non-monotonic features in the {sup 210}Pb profile and activities that were not at supported levels at the base of the core. Selected results are that: (1) drawdown significantly influenced sedimentation patterns causing slopes for {sup 210}Pb profiles that reflected the influx of older sediment, (2) periods of Fe production correlate to Hg loading indicating the point source for contamination, a relationship not previously identified, (3) Hg:Al ratios indicate a recent change to a watershed pathway for Hg loading and (4) Hg concentrations had decreased from

  6. Evidence for stagnation of the Harvard sublobe (Lake Michigan lobe) in Northeastern Illinois, U.S.A., from 24 000 to 17 600 BP and subsequent tundra-like ice-marginal paleoenvironments from 17 600 to 15 700 BP

    Science.gov (United States)

    Curry, B. Brandon; Yansa, C.H.

    2004-01-01

    Glacial deposits of the last glaciation associated with the Harvard sublobe (Lake Michigan lobe) in northeastern Illinois, U.S.A., occur between sediment with dateable organics. The lower organics include fragments of Picea sp. as young as 24 000 ?? 270 BP. The supraglacial organics occur sparsely in laminated silt and fine sand in landforms that are positioned relatively high on the landscape, such as deposits from ice-walled lakes. These terrestrial organics yield ages that are 2500 to 1300 14C years older than organics at the base of sediment successions in nearby kettle basins. Basal 14C ages from four upland sites range from 17 610 ?? 270 to 16 120 ?? 80 BP. Our revised time-distance diagram of the Harvard sublobe now reflects a period of stagnation from 24 000 to about 17 600 BP. The supraglacial lacustrine silt yielded plant macrofossil assemblages of primarily tundra plants, including Salix herbacea and Dryas integrifolia. These plants likely grew in supraglacial and ice-marginal environments. The ostracode fauna include Cytherissa lacustris and Limnocythere friabilis. Geomorphic relations and ostracode ecology indicate that more than 17 m of ice buttressed some of the supraglacial lakes.

  7. Studies of dry deposition of trace elements and diesel soot onto Lake Michigan and the Chesapeake Bay

    International Nuclear Information System (INIS)

    Ondov, J.M.; Caffrey, P.F.; Suarez, A.E.; Han, M.; Borgoul, P.V.

    1995-01-01

    As part of the Atmospheric Exchange Over Lakes and Oceans Study (AEOLOS) study, the University of Maryland participated in four intensive field campaigns, three on Lake Michigan (LM) and one on the Chesapeake Bay (CB), to determine the size distributions of potentially toxic elemental aerosol constituents, determine their sources, and their dry deposition loadings to surface waters. The work further seeks to elucidate the relative importance of constituents of fine- and coarse particles, as differentiation of these modes is essential to the eventual formation of control strategies. Unique components of the UMCP studies include (1) resolution of toxic elemental components of aerosol particles depositing to LM and CB by particle size and by source and (2) a Lake-wide evaluation of the importance of fine and coarse particle deposition to inorganic contamination of LM surface waters. In addition, a unique component of the Baltimore Study was the application of a sensitive iridium tracer to intentionally tag emissions form the City of Baltimore's sanitation truck fleet to tag the Baltimore urban plume and to determine the atmospheric behavior of diesel soot particles, a major source of urban carbon aerosol and the principle carrier of toxic polynuclear aromatic hydrocarbons. The work encompasses results for >40 elements by X-ray fluorescence and instrumental neutron activation analyses of more than 700 individual size-segregated aerosol, deposition, urban dust, and surface-water-suspended particulate samples. An overview of the results of these studies will be presented

  8. Recent increases in sediment and nutrient accumulation in Bear Lake, Utah/Idaho, USA

    Science.gov (United States)

    Smoak, J.M.; Swarzenski, P.W.

    2004-01-01

    This study examines historical changes in sediment and nutrient accumulation rates in Bear Lake along the northeastern Utah/Idaho border, USA. Two sediment cores were dated by measuring excess 210Pb activities and applying the constant rate of supply (CRS) dating model. Historical rates of bulk sediment accumulation were calculated based on the ages within the sediment cores. Bulk sediment accumulation rates increased throughout the last 100 years. According to the CRS model, bulk sediment accumulation rates were TOC) were calculated by multiplying bulk sediment accumulation rates times the concentrations of these nutrients in the sediment. Accumulation rates of TP, TN, TIC, and TOC increased as a consequence of increased bulk sediment accumulation rates after the re-connection of Bear River with Bear Lake.

  9. Prospects of obtaining samples of bottom sediments from subglacial lake Vostok

    Directory of Open Access Journals (Sweden)

    Н. И. Васильев

    2017-04-01

    Full Text Available The paper proves the timeliness of obtaining and examining bottom sediments from subglacial Lake Vostok. Predictive geological section of Lake Vostok and information value of bottom sediments have been examined. Severe requirements towards environmental security of lake examinations and sampling of bottom sediments rule out the use of conventional drilling technologies, as they would pollute the lake with injection liquid from the borehole. In order to carry out sampling of bottom sediments from the subglacial lake, it is proposed to use a dynamically balanced tool string, which enables rotary drilling without any external support on borehole walls to transmit counter torque.     A theoretical analysis has been carried out to assess the operation of the tool string, which is a two-mass oscillatory electromechanical system of reciprocating and rotating motion (RRM with two degrees of freedom.

  10. Hidden plastics of Lake Ontario, Canada and their potential preservation in the sediment record

    International Nuclear Information System (INIS)

    Corcoran, Patricia L.; Norris, Todd; Ceccanese, Trevor; Walzak, Mary Jane; Helm, Paul A.; Marvin, Chris H.

    2015-01-01

    Microplastics are a source of environmental pollution resulting from degradation of plastic products and spillage of resin pellets. We report the amounts of microplastics from various sites of Lake Ontario and evaluate their potential for preservation in the sediment record. A total of 4635 pellets were sampled from the Humber Bay shoreline on three sampling dates. Pellet colours were similar to those from the Humber River bank, suggesting that the river is a pathway for plastics transport into Lake Ontario. Once in the lake, high density microplastics, including mineral-polyethylene and mineral-polypropylene mixtures, sink to the bottom. The minerals may be fillers that were combined with plastics during production, or may have adsorbed to the surfaces of the polymers in the water column or on the lake bottom. Based on sediment depths and accumulation rates, microplastics have accumulated in the offshore region for less than 38 years. Their burial increases the chance of microplastics preservation. Shoreline pellets may not be preserved because they are mingled with organic debris that is reworked during storm events. - Highlights: • We determine the amount of microplastics in Lake Ontario shore and bottom sediments. • Pellet preservation in shoreline sediment is unlikely. • Microplastics have been accumulating in bottom sediments over <38 years. • Buried plastics in lake bottom sediment have a high potential for preservation. - Microplastics were identified in bottom sediments of Lake Ontario. Their burial could result in microplastics preservation in the future rock record

  11. Wind influence on the course of sedimentation processes of the laminated lacustrine sediments of Lake Czechowskie

    Science.gov (United States)

    Wiśniewska, Daria; Kramkowski, Mateusz; Tyszkowski, Sebastian

    2016-04-01

    The studies of the laminated lacustrine sediments play a very important role in the analysis of climate change. They provide valuable information related to the response of the ecosystem to changes in the environment. The condition for the development of the annual lamination is calm sedimentation, which can be compromised by the movement of water caused by waving. The depth to which this movement affects depends on the shape of the lake basin as well as the velocity and direction of the wind. During the study of sedimentary processes of laminated deposits in Lake Czechowskie (Tuchola Forest, North Poland, 53°52'N, 18°14' E, 108 m asl), the following question arose: How strong was the influence of the wind on the processes of lacustrine sedimentation? The key in getting the answers was the use of GIS techniques. Lake Czechowskie has an area of 76.6 hectares; it has two deeps separated by a threshold: a deeper one of 33 m (maximum depth of the basin) in the central-eastern part, and a shallower of 13 m in the western part. The speed of movement of water that is able to move sediment from the bottom of the lake, called the orbital wave velocity, is the basis for the designation of areas where re-suspension takes place. To calculate the wave parameters, the process of mixing, as well as the designation of re-suspension zones, the tool-script Wave Model (Rohweder et al. 2008) in the program ArsGIS 10.1 was used. The input data were wind direction and velocity from the meteorological station of Wirty about 15 km away, bathymetric data from acoustic profiling, and the Maximum Orbital Wave Velocity. The elements taken into account include maximum wind velocity of the multi-year 1996-2013, with particular emphasis on hurricanes Ksawery (December 2013) and Yoda (November 2011), during which wind velocity exceeded 120 km/h. In addition, maximum wind velocity ever recorded in the Polish Lowlands was considered. On the basis of the modelling, the authors delimited the areas

  12. A model for landscape development in terms of shoreline displacement, sediment dynamics, lake formation, and lake choke-up processes

    International Nuclear Information System (INIS)

    Brydsten, Lars

    2006-12-01

    This project expands on the study 'A mathematical model for lake ontogeny in terms of filling with sediments and macrophyte vegetation' published in SKB TR-04-09. As the title suggests, this older model focuses on lakes (existing and future lakes). This newer study extends the model to examine progress of terrestrial objects such as mires or arable land. Furthermore, this newer model could simulate progress of the areas close to the objects. These areas are divided according to their watershed boundaries. If two or more objects are situated along the same brook, the lower situated area is defined as its catchments minus the catchments of the closest higher situated object. The model encourages the study of an object situated in the sea from the time of deglaciation (c. 10,000 BP) to the time for the object due to positive shore displacement is situated on land or that a lake object has progressed to a wetland, however not longer than 18,000 AP. The model focuses on the object and its location in 100-year steps. The model is written in VisualBasic and is divided into two modules, a marine module and a lake module. The marine module deals with shoreline displacement, erosion and accumulation of postglacial fine-grained sediments and erosion of glacial clay. Inputs to the marine module are a digital elevation model (DEM), a digital map showing the extension of the objects and a marine quaternary map. The two maps are in raster formats with exactly the same formats (extension and cell sizes) as the DEM. For each time step the water depths at each pixel are calculated using a shore displacement equation. Next, the water depth changes due to sediment dynamics are calculated using the following rules; accumulation of fine-grained sediments are allowed if the pixel is situated within a future lake object; erosion of fine-grained sediment is allowed if the pixel is not within a future lake object and the marine quaternary map shows occurrence of postglacial sediments and

  13. A model for landscape development in terms of shoreline displacement, sediment dynamics, lake formation, and lake choke-up processes

    Energy Technology Data Exchange (ETDEWEB)

    Brydsten, Lars [Umeaa University, Dept. of Ecology and Environmental Science (Sweden)

    2006-12-15

    This project expands on the study 'A mathematical model for lake ontogeny in terms of filling with sediments and macrophyte vegetation' published in SKB TR-04-09. As the title suggests, this older model focuses on lakes (existing and future lakes). This newer study extends the model to examine progress of terrestrial objects such as mires or arable land. Furthermore, this newer model could simulate progress of the areas close to the objects. These areas are divided according to their watershed boundaries. If two or more objects are situated along the same brook, the lower situated area is defined as its catchments minus the catchments of the closest higher situated object. The model encourages the study of an object situated in the sea from the time of deglaciation (c. 10,000 BP) to the time for the object due to positive shore displacement is situated on land or that a lake object has progressed to a wetland, however not longer than 18,000 AP. The model focuses on the object and its location in 100-year steps. The model is written in VisualBasic and is divided into two modules, a marine module and a lake module. The marine module deals with shoreline displacement, erosion and accumulation of postglacial fine-grained sediments and erosion of glacial clay. Inputs to the marine module are a digital elevation model (DEM), a digital map showing the extension of the objects and a marine quaternary map. The two maps are in raster formats with exactly the same formats (extension and cell sizes) as the DEM. For each time step the water depths at each pixel are calculated using a shore displacement equation. Next, the water depth changes due to sediment dynamics are calculated using the following rules; accumulation of fine-grained sediments are allowed if the pixel is situated within a future lake object; erosion of fine-grained sediment is allowed if the pixel is not within a future lake object and the marine quaternary map shows occurrence of postglacial

  14. Estimation of sediment sources using selected chemical tracers in the Perry lake basin, Kansas, USA

    Science.gov (United States)

    Juracek, K.E.; Ziegler, A.C.

    2009-01-01

    The ability to achieve meaningful decreases in sediment loads to reservoirs requires a determination of the relative importance of sediment sources within the contributing basins. In an investigation of sources of fine-grained sediment (clay and silt) within the Perry Lake Basin in northeast Kansas, representative samples of channel-bank sources, surface-soil sources (cropland and grassland), and reservoir bottom sediment were collected, chemically analyzed, and compared. The samples were sieved to isolate the TOC), and 137Cs were selected for use in the estimation of sediment sources. To further account for differences in particle-size composition between the sources and the reservoir bottom sediment, constituent ratio and clay-normalization techniques were used. Computed ratios included TOC to TN, TOC to TP, and TN to TP. Constituent concentrations (TN, TP, TOC) and activities (137Cs) were normalized by dividing by the percentage of clay. Thus, the sediment-source estimations involved the use of seven sediment-source indicators. Within the Perry Lake Basin, the consensus of the seven indicators was that both channel-bank and surface-soil sources were important in the Atchison County Lake and Banner Creek Reservoir subbasins, whereas channel-bank sources were dominant in the Mission Lake subbasin. On the sole basis of 137Cs activity, surface-soil sources contributed the most fine-grained sediment to Atchison County Lake, and channel-bank sources contributed the most fine-grained sediment to Banner Creek Reservoir and Mission Lake. Both the seven-indicator consensus and 137Cs indicated that channel-bank sources were dominant for Perry Lake and that channel-bank sources increased in importance with distance downstream in the basin. ?? 2009 International Research and Training Centre on Erosion and Sedimentation and the World Association for Sedimentation and Erosion Research.

  15. Arctic deltaic lake sediments as recorders of fluvial organic matter deposition

    Directory of Open Access Journals (Sweden)

    Jorien E Vonk

    2016-08-01

    Full Text Available Arctic deltas are dynamic and vulnerable regions that play a key role in land-ocean interactions and the global carbon cycle. Delta lakes may provide valuable historical records of the quality and quantity of fluvial fluxes, parameters that are challenging to investigate in these remote regions. Here we study lakes from across the Mackenzie Delta, Arctic Canada, that receive fluvial sediments from the Mackenzie River when spring flood water levels rise above natural levees. We compare downcore lake sediments with suspended sediments collected during the spring flood, using bulk (% organic carbon, % total nitrogen, 13C, 14C and molecular organic geochemistry (lignin, leaf waxes. High-resolution age models (137Cs, 210Pb of downcore lake sediment records (n=11 along with lamina counting on high-resolution radiographs show sediment deposition frequencies ranging between annually to every 15 years. Down-core geochemical variability in a representative delta lake sediment core is consistent with historical variability in spring flood hydrology (variability in peak discharge, ice jamming, peak water levels. Comparison with earlier published Mackenzie River depth profiles shows that (i lake sediments reflect the riverine surface suspended load, and (ii hydrodynamic sorting patterns related to spring flood characteristics are reflected in the lake sediments. Bulk and molecular geochemistry of suspended particulate matter from the spring flood peak and lake sediments are relatively similar showing a mixture of modern higher-plant derived material, older terrestrial permafrost material, and old rock-derived material. This suggests that deltaic lake sedimentary records hold great promise as recorders of past (century-scale riverine fluxes and may prove instrumental in shedding light on past behaviour of arctic rivers, as well as how they respond to a changing climate.

  16. Identification of hot spot area of sediment contamination in a lake system using texture characteristics.

    Science.gov (United States)

    Sheela, A M; Letha, J; Joseph, Sabu; Thomas, Jobin

    2013-04-01

    Texture plays an important role in the identification of polluted stretch in a lake system. The organic matter as well as toxic elements get accumulated in the finer sediments. The aim of the work is to show the spatio-temporal distribution of texture of the lake sediment (Akkulam-Veli lake, Kerala) and to identify the hot spot areas of contamination. Hot spot areas vary with seasons. During PRM, (premonsoon), the upstream portion of the Akkulam lake is the hot spot. During MON (monsoon), the downstream portion of the Akkulam lake and the upstream portion of the Veli lake are the hot spots. During POM (postmonsoon), hot spot area is the downstream portion of the Akkulam lake. This methodology can be used for the quick identification of hot spots in water bodies.

  17. Urbanization increased metal levels in lake surface sediment and catchment topsoil of waterscape parks

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hong-Bo [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Yu, Shen, E-mail: syu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Li, Gui-Lin [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Liu, Yi; Yu, Guang-Bin [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Deng, Hong [Department of Environmental Sciences, Tiantong National Station of Forest Ecosystem, Key Laboratory of Urbanization and Ecological Restoration, East China Normal University, Shanghai 200062 (China); Wu, Sheng-Chun [State Key Laboratory in Marine Pollution, Biology and Chemistry Department, City University of Hong Kong, Hong Kong (China); Wong, Ming-Hung [Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Hong Kong (China)

    2012-08-15

    Lake surface sediment is mainly derived from topsoil in its catchment. We hypothesized that distribution of anthropogenic metals would be homogenous in lake surface sediment and the lake's catchment topsoil. Anthropogenic metal distributions (cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) in fourteen waterscape parks were investigated in surface sediments and catchment topsoils and possible source homogeneity was tested using stable Pb isotopic ratio analysis. The parks were located along an urbanization gradient consisting of suburban (SU), developing urban (DIU), developed urban (DDU), and central urban core (CUC) areas in Shanghai, China. Results indicated that surface lake sediments and catchment topsoils in the CUC parks were highly contaminated by the investigated anthropogenic metals. Total metal contents in surface sediment and topsoil gradually increased along the urbanization gradient from the SU to CUC areas. Generally, the surface sediments had greater total metal contents than their catchment topsoils. These results suggest that urbanization drives the anthropogenic metal enrichment in both surface sediment and its catchment topsoil in the waterscape parks. Soil fine particles (< 63 {mu}m) and surface sediments had similar enrichment ratios of metals, suggesting that surface runoff might act as a carrier for metals transporting from catchment to lake. Stable Pb isotope ratio analysis revealed that the major anthropogenic Pb source in surface sediment was coal combustion as in the catchment topsoil. Urbanization also correlated with chemical fractionation of metals in both surface sediment and catchment topsoil. From the SU to the CUC parks, amounts of labile metal fractions increased while the residual fraction of those metals remained rather constant. In short, urbanization in Shanghai drives anthropogenic metal distribution in environmental matrices and the sources were homogenous. -- Highlights: Black-Right-Pointing-Pointer Obvious

  18. Urbanization increased metal levels in lake surface sediment and catchment topsoil of waterscape parks

    International Nuclear Information System (INIS)

    Li, Hong-Bo; Yu, Shen; Li, Gui-Lin; Liu, Yi; Yu, Guang-Bin; Deng, Hong; Wu, Sheng-Chun; Wong, Ming-Hung

    2012-01-01

    Lake surface sediment is mainly derived from topsoil in its catchment. We hypothesized that distribution of anthropogenic metals would be homogenous in lake surface sediment and the lake's catchment topsoil. Anthropogenic metal distributions (cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) in fourteen waterscape parks were investigated in surface sediments and catchment topsoils and possible source homogeneity was tested using stable Pb isotopic ratio analysis. The parks were located along an urbanization gradient consisting of suburban (SU), developing urban (DIU), developed urban (DDU), and central urban core (CUC) areas in Shanghai, China. Results indicated that surface lake sediments and catchment topsoils in the CUC parks were highly contaminated by the investigated anthropogenic metals. Total metal contents in surface sediment and topsoil gradually increased along the urbanization gradient from the SU to CUC areas. Generally, the surface sediments had greater total metal contents than their catchment topsoils. These results suggest that urbanization drives the anthropogenic metal enrichment in both surface sediment and its catchment topsoil in the waterscape parks. Soil fine particles (< 63 μm) and surface sediments had similar enrichment ratios of metals, suggesting that surface runoff might act as a carrier for metals transporting from catchment to lake. Stable Pb isotope ratio analysis revealed that the major anthropogenic Pb source in surface sediment was coal combustion as in the catchment topsoil. Urbanization also correlated with chemical fractionation of metals in both surface sediment and catchment topsoil. From the SU to the CUC parks, amounts of labile metal fractions increased while the residual fraction of those metals remained rather constant. In short, urbanization in Shanghai drives anthropogenic metal distribution in environmental matrices and the sources were homogenous. -- Highlights: ► Obvious urbanization effect on metal

  19. Sedimentation in Lake Onalaska, Navigation Pool 7, upper Mississippi River, since impoundment

    Science.gov (United States)

    Korschgen, C.E.; Jackson, G.A.; Muessig, L.F.; Southworth, D.C.

    1987-01-01

    Sediment accumulation was evaluated in Lake Onalaska, a 2800-ha backwater impoundment on the Upper Mississippi River. Computer programs were used to process fathometric charts and generate an extensive data set on water depth for the lake. Comparison of 1983 survey data with pre-impoundment (before 1937) data showed that Lake Onalaska had lost less than 10 percent of its original mean depth in the 46 years since impoundment. Previous estimates of sedimentation rates based on Cesium-137 sediment core analysis appear to have been too high. (DBO)

  20. Midwest Flood of 2008: Lake Michigan Basin-Wide Summer Plankton Bloom is not due to Nutrient Injection

    Science.gov (United States)

    Cuhel, R. L.; Aguilar, C.; Balch, B.

    2008-12-01

    Major Midwestern US flooding occurred in June of 2008 following over 30cm of rainfall in a 4-day period. Tributaries to Lake Michigan swelled, with outflow from the Milwaukee River increasing 30-fold from long-term means of 8.5 m3/s to over 250 m3/s. Flood stage was sustained for 8 days and dampened over a protracted 30-day period. A series of inshore, transect, and mid-lake cruises established the presence of unseasonally strong gradients in surface phytoplankton biomass moving progressively offshore, to ultimately influence at least half of the 150 km-wide Lake Michigan basin. Remote sensing of chlorophyll (chl) and the diffuse attenuation coefficient (at 490nm) documented the existence of blooms offshore of each major river on both sides of the lake persisting into mid-July, and then disappearing from surface waters, not visible to space-based satellite sensors. Profiles detailed deep chlorophyll maxima that were distinct from previous years. Surface transects in 2007 yielded typical summer chl of quagga mussel-infested shallower reef zone. Offshore transects displayed high chl in the upper 5m only a few days after the onset of high flow. Unseasonably high phytoplankton population densities progressed with time and distance offshore in a manner suggestive of advection of a surface lens across the well-stratified lake. As the lens progressed offshore, populations continued to grow, appearing as a band of high chl extending across the lake. After 2 weeks, inshore areas had substantially lower surface biomass than those offshore, reflecting settling of denser cells during a long period of relatively calm weather. Development of deep chlorophyll maxima (DCM) at 25-40m followed the decrease of surface populations at all locations deeper than 50m. High satellite- derived diffuse attenuation coefficients also reflected the presence of dense algal populations in the upper water column. 1% PAR penetration reached to only 25m, substantially short of the 35-40m

  1. Microplastic pollution in Vembanad Lake, Kerala, India: The first report of microplastics in lake and estuarine sediments in India.

    Science.gov (United States)

    Sruthy, S; Ramasamy, E V

    2017-03-01

    We present the first study of microplastics in the sediments of Vembanad Lake, a Ramsar site in India. Microplastics are emerging pollutants of increasing environmental concern with a particle size of microplastics pollution on the environment and biota is not well known. Vast data exist in the literature on marine microplastics while reports on freshwater ecosystems are scarce. In this context, to examine the occurrence of microplastic particles (MPs) in the Vembanad Lake, samples were collected from ten sites and processed for microplastic extraction through density separation. Identification of the polymer components of MPs was done using micro Raman spectroscopy. MPs were recovered from all sediment samples, indicating their extensive distribution in the lake. The abundance of MPs recorded from the sediment samples is in the range of 96-496 particles m -2 with a mean abundance of 252.80 ± 25.76 particles m -2 . Low density polyethylene has been identified as the dominant type of polymer component of the MPs. As clams and fishes are the major source of protein to the local population, the presence of MPs in the lake becomes critically important, posing a severe threat of contaminating the food web of this lake. This study, being the first report from India on MPs in lake sediments, provide impetus for further research on the distribution and impact of this emerging pollutant on the biota of many aquatic systems spread across India. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Role of sulfate reduction in long term accumulation of organic and inorganic sulfur in lake sediments

    International Nuclear Information System (INIS)

    Rudd, J.W.M.; Kelly, C.A.; Furutani, A.

    1986-01-01

    Sulfate reduction and the accumulation of reduced sulfur in epilimnetic sediments were studied in lakes in southern Norway, the Adirondack Mountains, and at the Experimental Lakes Area (ELA) of northwestern Ontario. In all of the lakes, sulfate reduction produced substantial quantities of pyrite and organic sulfur compounds. In 9-month in situ experiments at ELA using 35 S, there was a large loss (55%) with time of the S initially reduced and deposited in the sediments and a preferential loss of inorganic S compounds which led to a predominance of organic 35 S accumulation in the sediments. An intensive study of long term accumulation of sulfur in the epilimnetic sediments of four Adirondack lakes also showed that the most important long term end product of sulfate reduction was organic S and that sulfate reduction was the major source of S to the sediments. Because of high concentrations of iron in all of the sediments samples and because of the long term storage of sulfur in sediments, mostly as organic S, iron did not limit iron sulfide accumulation in these sediments. Iron limitation is unlikely to occur except in unusual circumstances. This study indicates that formation of organic S in epilimnetic sediments is primarily responsible for H + consumption via sulfate reduction in acidified lakes

  3. Matuyama/Brunhes Polarity Transition in Owens Lake, CA, Sediment

    Science.gov (United States)

    Liddicoat, Joseph; Kravchinsky, Vadim

    2014-05-01

    The complexity of the Matuyama/Brunhes (M/B) polarity transition is becoming better understood from investigations of volcanic rocks (Coe et al., 2004), loess (Jin et al., 2012; Evans et al., 2011; Kravchinsky, 2013), and marine (Clement and Opdyke, 1982; Hartl and Tauxe, 1996; Macri et al., 2010) and lacustrine (Valet et al., 1988; Sagnotti et al., 2013) sediments. The transition appears to include a brief interval of normal polarity prior to the entry into the Brunhes Normal Chron (Coe et al., 2004; Jin et al., 2012; Evans et al., 2011), and the transition has Virtual Geomagnetic Poles rapidly moving from the Southern Hemisphere to the Northern Hemisphere (Coe et al., 2004; Jin et al., 2012; Evans et al., 2011; Sagnotti et al., 2013). The M/B polarity transition is recorded in exposed Pleistocene lake sediments near Bishop, CA, where the brief interval of normal polarity noted above is present and the change from full reverse to full normal polarity occurs rapidly. The brief interval of normal polarity is recorded at two sites separated laterally by about 150 m and is in single hand samples measured at vertical spacing of 2.0-2.5 cm using six samples per measured level and alternating field demagnetization at 20 mT (Liddicoat, 1993, Table 1 and Fig. 8). The siltstone is unweathered glacial flour from the Sierra Nevada that borders the western side of Owens Valley where the sediments were deposited in Owens Lake. In the siltstone, the majority of the samples have a percentage of about 60 percent where the grain diameter is less than 63 micrometres, and in those samples there is about a five percent fraction when the diameter is two micrometres or less. The Total Inorganic Carbon in most samples is about 0.25 percent (Bergeron, 2013), and magnetite is the dominant carrier of the magnetization (Liddicoat, 1993). The palaeomagnetic directions recording the terminus of the full M/B transition, which occurs before the field intensity is completely recovered, spans no

  4. Lake Mixing Regime Influences Arsenic Transfer from Sediments into the Water Column and Uptake in Plankton

    Science.gov (United States)

    Gawel, J.; Barrett, P. M.; Hull, E.; Burkart, K.; McLean, J.; Hargrave, O.; Neumann, R.

    2017-12-01

    The former ASARCO copper smelter in Ruston, WA, now a Superfund site, contaminated a large area of the south-central Puget Sound region with arsenic over its almost 100-year history. Arsenic, a priority Superfund contaminant and carcinogen, is a legacy pollutant impacting aquatic ecosystems in urban lakes downwind of the ASARCO emissions stack. We investigated the impact of lake mixing regime on arsenic transfer from sediments into lake water and aquatic biota. We regularly collected water column and plankton samples from four study lakes for two years, and deployed sediment porewater peepers and sediment traps to estimate arsenic flux rates to and from the sediments. In lakes with strong seasonal stratification, high aqueous arsenic concentrations were limited to anoxic hypolimnetic waters while low arsenic concentrations were observed in oxic surface waters. However, in polymictic, shallow lakes, we observed elevated arsenic concentrations throughout the entire oxic water column. Sediment flux estimates support higher rates of arsenic release from sediments and vertical transport. Because high arsenic in oxic waters results in spatial overlap between arsenate, a phosphate analog, and lake biota, we observed enhanced trophic transfer of arsenic in polymictic, shallow study lakes, with higher arsenic accumulation (up to an order of magnitude) in both phytoplankton and zooplankton compared to stratified lakes. Chemical and physical mechanisms for higher steady-state arsenic concentrations will be explored. Our work demonstrates that physical mixing processes coupled with sediment/water redox status exert significant control over bioaccumulation, making shallow, periodically-mixed urban lakes uniquely vulnerable to environmental and human health risks from legacy arsenic contamination.

  5. Sediment dynamics in a large shallow lake characterized by seasonal flood pulse in Southeast Asia.

    Science.gov (United States)

    Siev, Sokly; Yang, Heejun; Sok, Ty; Uk, Sovannara; Song, Layheang; Kodikara, Dilini; Oeurng, Chantha; Hul, Seingheng; Yoshimura, Chihiro

    2018-08-01

    Most of studies on sediment dynamics in stable shallow lakes focused on the resuspension process as it is the dominant process. However, understanding of sediment dynamics in a shallow lake influenced by flood pulse is unclear. We tested a hypothesis that floodplain vegetation plays as a significant role in lessening the intensity of resuspension process in a shallow lake characterized by the flood pulse system. Therefore, this study aimed to investigate sediment dynamics in this type of shallow lake. The target was Tonle Sap Lake (TSL), which is a large shallow lake influenced by a flood pulse system of Mekong River located in Southeast Asia. An extensive and seasonal sampling survey was conducted to measure total suspended solid (TSS) concentrations, sedimentation and resuspension rates in TSL and its 4 floodplain areas. The study revealed that sedimentation process was dominant (TSS ranged: 3-126mgL -1 ) in the high water period (September-December) while resuspension process was dominant (TSS ranged: 4-652mgL -1 ) only in the low water period (March-June). In addition, floodplain vegetation reduced the resuspension of sediment (up to 26.3%) in water. The implication of the study showed that resuspension is a seasonally dominant process in shallow lake influenced by the flood pulse system at least for the case of TSL. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. The preglacial sediment record of Lake Ladoga, Russia - first results from a seismic survey and sediment coring in 2013

    Science.gov (United States)

    Melles, Martin; Krastel, Sebastian; Fedorov, Grigory; Subetto, Dmitry A.; Savelieva, Larisa A.; Andreev, Andrej; Wagner, Bernd

    2014-05-01

    The new German-Russian project PLOT (Paleolimnological Transect) aims at investigating the Late Quaternary climatic and environmental history along a more than 6000 km long longitudinal transect crossing northern Eurasia. Special emphasis is put on the preglacial history. For this purpose shallow and deep seismic surveys shall be carried out on five lakes, which potentially host preglacial sediment records, followed by sediment coring based on the results of the seismic campaigns. The well-studied Lake El'gygytgyn represents the eastern-most location of the transect and acts as reference site. Within the scope of a pilot phase for the PLOT project, funded by the German Federal Ministry of Education and Research, we were able to investigate Lake Ladoga, which is located close to St. Petersburg at the western end of the transect. Lake Ladoga is the largest lake in Europe, covering an area of almost 18.000 km2. The modern sedimentation as well as the late glacial and Holocene history of the lake were already studied in detail over the past decades. The older, preglacial lake history, however, is only rudimentary known from a core transect drilled in the southern lake in the 1930th. The cores of up to about 60 m length were only briefly described and are not existing any more. The results from these cores, known from unpublished reports only, suggest the existence of marine sediments of presumably Eemian age, representing a time when Lake Lagoga was part of a precursor of the Baltic Sea, which had a connection via Ladoga and Onega Lakes to the White Sea and further to the Arctic Ocean. In late August/early September 2013 we carried out a seismic survey on Lake Ladoga using a Mini-GI-Gun and a 32-channel seismic streamer. In total, 1500 km of seismic profiles were measured, covering most parts of the lake. The seismic lines typically show acoustically well stratified Holocene muds overlaying rather transparent postglacial varves. These sediment successions can reach

  7. Modelling land cover change effects on catchment-to-lake sediment transfer

    Science.gov (United States)

    Smith, Hugh; Peñuela Fernández, Andres; Sellami, Haykel; Sangster, Heather; Boyle, John; Chiverrell, Richard; Riley, Mark

    2017-04-01

    Measurements of catchment soil erosion and sediment transfer to streams and lakes are limited and typically short duration (physical and social records coupled with high-resolution, sub-annual simulations of catchment-to-lake soil erosion and sedimentation. This choice of modelling period represents a compromise between the length of record and data availability for model parameterisation. We combine historic datasets for climate and land cover from four lake catchments in Britain with a fully revised catchment-scale modelling approach based on the Morgan-Morgan-Finney model, called MMF-TWI, that incorporates new elements representing plant growth, soil water balance and variable runoff and sediment contributing areas. The catchments comprise an intensively-farmed lowland agricultural catchment and three upland catchments. Historic change simulations were compared with sedimentation rates determined from multiple dated cores taken from each lake. Our revised modelling approach produced generally comparable rates of lake sediment flux to those based on sediment archives. Moreover, these centennial scale records form the basis for examining hypothetical scenarios linked to changes in crop rotation (lowland) and riparian re-afforestation (uplands), as well as providing an extended historic baseline against which to compare future climate effects on runoff, erosion and lake sediment delivery.

  8. Lake ecosystem response to rapid lateglacial climate changes in lake sediments from northern Poland

    Science.gov (United States)

    Słowiński, Michał; Zawiska, Izabela; Ott, Florian; Noryśkiewicz, Agnieszka M.; Apolinarska, Karina; Lutyńska, Monika; Michczyńska, Danuta J.; Brauer, Achim; Wulf, Sabine; Skubała, Piotr; Błaszkiewicz, Mirosław

    2013-04-01

    During the Late Glacial Period environment changes were triggered by climatic oscillations which in turn controlled processes like, for example, permafrost thawing, vegetation development and ground water circulation. These environmental changes are ideally recorded in lake sediments and thus can be reconstructed applying a multi-poxy approach. Here, we present the results from the Trzechowskie paleolake, located in the northern Polish lowlands (eastern part of the Pomeranian Lakeland). The site is situated on the outwash plain of the Wda River, which was formed during the Pomeranian phase of the Vistulian glaciation ca 16,000 14C yrs BP. The depression of the Trzechowskie lake basin formed after melting of a buried ice block during the Allerød (13903±170 cal yrs BP). We reconstructed environmental changes in the Trzechowskie paleolake and its catchment using biotic proxies (macrofossils, pollen, cladocera, diatoms, oribatidae mite) and geochemical proxies (δ18O, δ13C, loss-on-ignition (LOI), CaCO3 content). In addition, we carried out µ-XRF element core scanning. The chronology has been established by means of biostratigraphyAMS14C dating on plant macro remains, varve counting in laminated intervals and the late Allerød Laacher See Tephra isochrone. Our results showed that biogenic accumulation in the lake started during the Bølling. Development of coniferous forest during the Allerød with dominance of Pinus sylvestris lead to leaching of carbonates in the catchment due to low pH increasing the flux of Ca ions into the lake. In consequence calcite precipitating in the lake increased as evidences by increasing CaCO3 contents. Both biotic and physical proxies clearly reflect the rapid decrease in productivity at the onset of the Younger Dryas. We compare the data from the Trzechowskie paleolake with the Meerfelder Maar and Rehwiese lake records based on tephrochronological synchronization using the Laacher See Tephra. This study is a contribution to the

  9. Gamma-emitting radionuclides in the bottom sediments of some Finnish lakes

    International Nuclear Information System (INIS)

    Ilus, E.; Puhakainen, M.; Saxen, R.

    1993-10-01

    In 1988 and 1990 bottom sediment and surface water samples were taken from eight large lakes representing all five categories of deposition regions contaminated by the chernobyl fallout in Finland. All samples were analysed for gamma-emitting radionuclides. The 137 Cs concentrations in surface waters varied in 1988 from 20 to 310 Bq/m 3 and in 1990 from 78 to 170 Bq/m 3 . The other radionuclides of Chernobyl origin detected in water samples were 106 Ru, 125 Sb and 134 Cs. In the sediments the total amount of 137 Cs per square metre varied in 1988 from 1100 to 160 000 Bq/m 2 and in 1990 from 14 000 to 250 000 Bq/m 2 . The maximum values were in Lake Pyhaejaervi. The maximum concentration of 137 Cs in the surface layer of sediment (0-2cm) was 55 700 Bq/kg dry wt in Lake Naesijaervi. In addition to the cesium isotopes 137 Cs and 134 Cs , Chernobyl derived 106 Ru, 125 Sb amd 144 Ce were detected i the surface layer of sediment in most lakes. 54 Mn, 60 Co and 110m Ag were also detected in some lakes situated in the regions most contaminated by the Chernobyl fallout. In 1988 the maximum concentrations of 137 Cs and 134 Cs were in the uppermost layer of sediment (0-2cm) at almost all stations. In 1990, the cesium peaks already occurred at many stations in the second slice (2-5cm), which may indicate downward diffusion of cesium in sediments or mixing of sediment layers during sampling. The most important factors affecting cesium values in sediments were the local amount of deposition and the type of sediment. This study did not reveal any correletion between the maximum depth of the lake and the area of the lake with the cesium amounts in the sediments. (orig.). (23 refs., 10 figs., 6 tabs.)

  10. What fraction of the total metal flux into lakes is retained in the sediments

    Energy Technology Data Exchange (ETDEWEB)

    Nriagu, J O; Wong, H K.T.

    1986-12-01

    The concentrations of, and deposition rates for, the pollutant metals (Pb, Cu, Zn, Ni, and Cd) and the rare earth elements are reported for the sediments and settling particulates in a large, remote lake (Lake Opeongo) in the Algonquin Provincial Park, Ontario. Using a mass conservation model based on the rare earth elements, it is estimated that only 40 to 60% of pollutant metals getting into the lake is retained by the sediments. The low retention rate may explain the widely reported intrabasin and intra-lake differences in metal contents of sediments and casts some doubt on the use of pollutant metal profiles in retrospective assessment of the human contribution to the metal flux into many lake basins. 22 references.

  11. An Overview of Sediment Organic Matter Records of Human Eutrophication in the Laurentian Great Lakes Region

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, Philip A. [University of Michigan, Department of Geological Sciences (United States)], E-mail: pameyers@umich.ed

    2006-12-15

    The isotopic and molecular compositions of organic matter buried in lake sediments provide information that helps to reconstruct past environmental conditions and to assess impacts of humans on local ecosystems. This overview of sedimentary records from the North American Great Lakes region describes examples of applications of organic geochemistry to paleolimnological reconstructions. These lakes experienced a succession of human-induced environmental changes that started after completion of the Erie Canal in 1825. Agricultural deforestation in the mid-nineteenth century released soil nutrients that increased algal productivity and caused an associated increase in algal biomarkers in sediment records. Eutrophication that accompanied magnified delivery of municipal nutrients to the lakes in the 1960s and 1970s created excursions to less negative {delta}{sup 13}C values in sediment organic matter. Increased organic carbon mass accumulation rates mirror the isotopic evidence of eutrophication in the Great Lakes.

  12. Applicability of API ZYM to capture seasonal and spatial variabilities in lake and river sediments.

    Science.gov (United States)

    Patel, Drashti; Gismondi, Renee; Alsaffar, Ali; Tiquia-Arashiro, Sonia M

    2018-05-02

    Waters draining into a lake carry with them much of the suspended sediment that is transported by rivers and streams from the local drainage basin. The organic matter processing in the sediments is executed by heterotrophic microbial communities, whose activities may vary spatially and temporally. Thus, to capture and evaluate some of these variabilities in the sediments, we sampled six sites: three from the St. Clair River and three from Lake St. Clair in spring, summer, fall, and winter of 2016. At all sites and dates, we investigated the spatial and temporal variations in 19 extracellular enzyme activities using API ZYM. Our results indicated that a broad range of enzymes were found to be active in the sediments. Phosphatases, lipases, and esterases were synthesized most intensively by the sediment microbial communities. No consistent difference was found between the lake and sediment samples. Differences were more obvious between sites and seasons. Sites with the highest metabolic (enzyme) diversity reflected the capacity of the sediment microbial communities to breakdown a broader range of substrates and may be linked to differences in river and lake water quality. The seasonal variability of the enzymes activities was governed by the variations of environmental factors caused by anthropogenic and terrestrial inputs, and provides information for a better understanding of the dynamics of sediment organic matter of the river and lake ecosystems. The experimental results suggest that API ZYM is a simple and rapid enzyme assay procedure to evaluate natural processes in ecosystems and their changes.

  13. ECOLOGICAL RISKS OF DIOXINS IN LAKE ONTARIO: A TALE OF TWO SEDIMENT CORES

    Science.gov (United States)

    Sediment box cores have frequently been used to determine organochlorine chemical loading histories of lakes and reservoirs. 137Cs and 210Pb radionuclide dating techniques are employed synchronously with chemical analyses of the contaminants for thin sections extruded from adjace...

  14. Patterns of microbial activity in the shallow bottom sediments of Lake ...

    African Journals Online (AJOL)

    FDA), was investigated in two sediment cores collected from Manzala Lake during November 2011. FDA hydrolysis positively correlated with total bacterial counts, bacterial biomass and chlorophyll a in both cores. The 10–20 cm subsurface layer ...

  15. Elemental composition of a deep sediment core from Lake Stocksjoen in the Forsmark area

    Energy Technology Data Exchange (ETDEWEB)

    Stroemgren, Maarten [Umeaa Univ. (Sweden). Dept. of Ecology and Environmental Sciences; Brunberg, Anna-Kristina [Uppsala Univ. (Sweden). Dept. of Ecology and Evolution/Limnology

    2006-10-15

    A deep sediment core was taken from Lake Stocksjoen, situated within the Forsmark site investigation area. The 55 cm long sediment core, representing the entire history of the lake (approx 430 years) was sliced in 5 cm portions and analysed for various chemical elements, using ICP-MS technique. In total, 54 different elements - classified as main elements, heavy metals and trace elements - were analysed. In general terms, three different patterns of stratigraphy were derived from all the analysed elements. Calcium, manganese, lead and mercury occurred in highest concentrations in the upper sediments (<30 cm depth). Phosphorus, zinc, cadmium, antimony, tin and strontium occurred in more even proportions throughout the sediment core. All the other elements were substantially reduced in the upper parts (<30 cm) compared to the deeper parts of the sediment core. Metals that are considered as airborne pollutants were found in low or moderate concentrations. This is in concert with other investigations of pollutants that have been performed in the Forsmark area. The sediment of Lake Stocksjoen is highly organic, and has been so during the entire history of the lake. Much of the organic Material seems to be refractory and less susceptible for mineralisation and respiration during the prevailing environmental conditions. This corresponds well with the characteristic gelatinous cyanophycee gyttja found in the lower parts of the sediment core. Although speculative, the pronounced changes in elemental composition of the sediment at 30 cm depth may correspond to the final isolation of the lake from the Baltic Sea, which occurred approximately 230 years ago. The deeper parts (below 30 cm depth) thus may represent the time period with regular intrusions of brackish water into the lake basin. One important factor governing the environmental conditions and the resulting elemental composition of the sediment is the unusually thick 'microbial mat', which is characteristic

  16. Proglacial lake sediments – a basis for uninterrupted chronicles of the Holocene glacier variations

    Directory of Open Access Journals (Sweden)

    M. Y. Alexandrin

    2015-01-01

    Full Text Available The article covers the origin of paleolimnological method in glaciology, concerns the theoretical background of the approach, and focuses on the principal methods of analysis of the lake sediments and creating the sedimentary age-depth models. Lake sediments can provide a basis for creating uninterrupted reconstructions of the Holocene glacier variations with high resolution. The fundament of paleolimnological method is based on the differences between glacial and non-glacial components of the bottom sediments of proglacial lakes. The glacial signal in the lake sediments was originally distinguished by measuring the organic content of the sediment (normally with loss-on-ignition and the magnetic properties of the sediment. Subsequent methods of analysis could yield more precision and normally include geochemical composition (with the use of high-resolution scanning x-ray fluorescence analysis, use of biogenic indicators (such as pollen and diatoms contained in the sediment and more. Obtaining the most accurate age of the sediment is a crucial question in subsequent application of the sediment parameters for reconstruction of glacier variability. The article covers various methods of dating the lake sediment – radiocarbon, Cs- and Pb-isotope dating, varve counting. Techniques of creating age-depth models are taken into account. A state-of-the-art application of sedimentary properties in paleoglaciology yields a reconstruction of a former equilibrium line altitude – ELA. The article focuses on the basis of the ELA reconstruction approach. Successful examples of reconstructions of glacier variations based on the lake sediments can be found throughout the majority of the glaciated regions of the planet. The article states the most prominent of them and gives an update on the current progress in paleolimnological research in the Caucasus Mountains.

  17. Vertical distributions of PAHs in the sediments of four lakes in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Takehiko; Watanabe, Seigo; Kamiya, Koichi [Tsukuba Univ., Ibaraki (Japan). Graduate School of Life and Environment; Ozaki, Noriatsu [Hiroshima Univ., Higashihiroshima (Japan). Graduate School of Engineering

    2012-12-15

    Purpose: The purpose of this study was to elucidate historical trends, spatial variations, and the sources of polycyclic aromatic hydrocarbons (PAHs) pollution in several Japanese lakes. Materials and methods: The vertical distributions of PAHs in the core samples of sediments taken at several points in lakes Kasumigaura, Suwa, Kizaki, and Shinji were determined using a gas chromatograph equipped with a mass selective detector and combined with chronological information and the physical/elemental properties of the sediment. Results and discussion: Seventeen related compounds (congeners) typically had concentration peaks at sediment depths corresponding to the 1960s to 1970s. In Lake Shinji and one bay of Lake Kasumigaura, there was a tendency for PAH concentrations to increase downstream; in contrast, another bay of Lake Kasumigaura showed the reverse trend. During big flood events, the fluxes of PAHs increased due to large inputs of particulate matter, although PAH concentrations were reduced. For the four study lakes and other similar lakes, PAH concentrations of surface sediments were approximately proportional to population densities in the respective watersheds, while the total input of PAHs to the lakes were correlated with their population and watershed area. The source apportionment analysis using isomer ratios for the congener profiles indicated that the principal sources of the PAHs in the lake sediments were gasoline and/or diesel engine exhausts and biomass burning. Conclusions: The observed concentration peaks showed a deterioration of the chemical quality of atmospheric conditions around 1960-1970 and a recent tendency for their amelioration. Between-lake differences suggest that the influence of human activity in the watersheds influences sediment PAH concentrations. The PAH sources were identified to be of pyrogenic origin. (orig.)

  18. Electricity generation by anaerobic bacteria and anoxic sediments from hypersaline soda lakes

    Science.gov (United States)

    Miller, L.G.; Oremland, R.S.

    2008-01-01

    Anaerobic bacteria and anoxic sediments from soda lakes produced electricity in microbial fuel cells (MFCs). No electricity was generated in the absence of bacterial metabolism. Arsenate respiring bacteria isolated from moderately hypersaline Mono Lake (Bacillus selenitireducens), and salt-saturated Searles Lake, CA (strain SLAS-1) oxidized lactate using arsenate as the electron acceptor. However, these cultures grew equally well without added arsenate using the MFC anode as their electron acceptor, and in the process oxidized lactate more efficiently. The decrease in electricity generation by consumption of added alternative electron acceptors (i.e. arsenate) which competed with the anode for available electrons proved to be a useful indicator of microbial activity and hence life in the fuel cells. Shaken sediment slurries from these two lakes also generated electricity, with or without added lactate. Hydrogen added to sediment slurries was consumed but did not stimulate electricity production. Finally, electricity was generated in statically incubated "intact" sediment cores from these lakes. More power was produced in sediment from Mono Lake than from Searles Lake, however microbial fuel cells could detect low levels of metabolism operating under moderate and extreme conditions of salt stress. ?? 2008 US Government.

  19. Fine sediment dynamics in a shallow lake and implication for design of hydraulic works

    NARCIS (Netherlands)

    Vijverberg, T.; Winterwerp, J.C.; Aarninkhof, S.G.J.; Drost, H.

    2010-01-01

    Lake Markermeer is a large (680 km2), shallow body of water in the middle of the Netherlands, with a mean water depth of 3.6 m. One of the major problems in the lake is its decreasing ecological value which is, among other reasons, caused by a gradual increase of suspended sediment concentration and

  20. Preliminary Report on Unique Laminated Holocene Sediments from the Qarun Lake in Egypt

    Directory of Open Access Journals (Sweden)

    Marks Leszek

    2016-06-01

    Full Text Available The Lake Qarun (Faiyum Oasis, northern Egypt is a relic of the much larger Holocene lake. Past lake levels and extensions were reconstructed, based on setting of archaeological sites scattered along northern paleoshores of the ancient lake. However, geoarcheological works did not yield enough data to establish continuous environmental history of the lake. A deep drilling FA-1 on the southeastern shore of the lake, performed in 2014, supplied with a core, 26 m long that is the one of the longest lake sediment cores in northeastern Africa. The basal section of the core consisted of thin-laminated diatom marly deposits, underlain at the Late Pleistocene/Holocene boundary by coarse-grained sands. The sediment lamine were quite well developed, especially in the lower part of the core. Preliminary results indicated annually deposited sediment sequence with seasonality signals provided by microlamine of diatoms, calcite, organic matter and clastic material. Early Holocene varved sediments from the Faiyum Oasis supplied with exceptional paleoenvironmental data for northeastern Africa, which enriched a record from previous logs drilled at the southwestern margin of the Qarun Lake.

  1. Trace metals in floodplain lake sediments : SEM/AVS as indicator of bioavailability and ecological effects

    NARCIS (Netherlands)

    Griethuysen, van C.

    2006-01-01

    This thesis addresses the geochemical aspects of AVS (Acid Volatile Sulfide) and SEM (Simultaneously Extracted Metals) in floodplain lake sediment, its spatial distribution in floodplain lakes and dynamics over time, the link with effects on single species (bioassays), as well as the impact of

  2. [Impacts of Asian clams (Corbicula fluminea) on lake sediment properties and phosphorus movement].

    Science.gov (United States)

    Zhang, Lei; Gu, Xiao-Zhi; Shao, Shi-Guang; Hu, Hai-Yan; Zhong, Ji-Cheng; Fan, Cheng-Xin

    2011-01-01

    To examine the impact of Corbicula fluminea on sediment properties and phosphorus dynamics across sediment-water interface in lake, the microcosm experiment was carried out with sediment and lake water from the estuary of Dapu River, a eutrophic area in Taihu Lake. Rhizon samplers were used to acquire pore water, and soluble reactive phosphorus (SRP) flux across sediment-water interface and sediment properties were determined. The activity of C. fluminea destroyed the initial sediment structure, mixed sediment in different depths, increased oxygen penetration depth, sediment water content, and total microbial activity in sediment. The downward movement of overlying water was enhanced by the activity of C. fluminea, which decreased Fe2+ in pore water by oxidation. The production of ferric iron oxyhydroxide adsorbed SRP from pore water and decreased SRP concentration in pore water, and this increased iron bound phosphorus in corresponding sediment. The emergence of C. fluminea accelerated SRP release from sediment to overlying water, and enhanced SRP flux increased with the rise of introduced C. fluminea density. Metabolization of C. fluminea might play an important role in accelerating SRP release.

  3. A hydrous Ca-bearing magnesium carbonate from playa lake sediments, Salines Lake, Spain

    Science.gov (United States)

    Queralt, I.; Julia, R.; Plana, F.; Bischoff, J.L.

    1997-01-01

    Sediments of playa Lake Salines, SE, Spain, contain a carbonate mineral characterized by X-ray diffraction peaks very similar to, but systematically shifted from those of pure magnesite. Analyses (SEM, IR and Raman spectroscopy, DTA, TGA, and ICP) indicate the mineral is a hydrous Ca-bearing magnesium carbonate with the chemical formula (Mg0.92,Ca0.08)CO3??3H2O. Thermal characteristics of the mineral are similar to those of other known hydrated magnesium carbonates. X-ray and electron diffraction data suggests a monoclinic system (P21/n space group) with unit-cell parameters of a = 6.063(6), b = 10.668(5), and c = 6.014(4) A?? and ?? = 107.28??.

  4. Inputting history of heavy metals into the inland lake recorded in sediment profiles: Poyang Lake in China

    International Nuclear Information System (INIS)

    Yuan Guoli; Liu Chen; Chen Long; Yang Zhongfang

    2011-01-01

    The temporal and spatial distribution of heavy metals (Cd, Hg, Pb, As and Cr) in Poyang Lake, the largest freshwater lake (3050 km 2 ) in China, were studied based on the sedimentary profiles. For this purpose, eight sedimentary cores were selected which located at lake area, outfall of lake and the main branch rivers, respectively. High-resolution profiles with interval 2 cm were used for analyzing the concentration of metals, and the ages of them were determined by 210 Pb and 137 Cs isotopic dating. While studying the change of metals concentration with the age in profile, it is found that the concentration of them in sediments was influenced not only by the sources in history but also by the sediment types. Based on this detailed work, the inventory and burden of heavy metals per decade were estimated in lake area during the past 50 years. Significantly, rivers-contribution ratio per decade was estimated to distinguish each river's contribution of heavy metals into lake while river-flux in history and metals concentration in profiles were considered as calculating factors. So, our research provides a proof to well understand the sedimentary history and the inputting history of heavy metals from main rivers into an inland lake.

  5. Sedimentation rate and chronology of As and Zn in sediment of a recent former tin mining lake estimated using Pb-210 dating technique

    International Nuclear Information System (INIS)

    Zaharidah Abu Bakar; Ahmad Saat; Zaini Hamzah; Abdul Khalik Wood; Zaharudin Ahmad

    2011-01-01

    Sedimentation in lake occurred through run-off from the land surface and settles on the bottom lake. Past mining activities might enhance sedimentation process in the former tin mining lakes either through natural or human activities. Former tin mining lakes were suspected to have high sedimentation rate due undisturbed environment for almost 50 years. To estimate sedimentation rate and metals contamination in this lake, Pb-210 dating technique was used. Two sediments cores were sampled using gravity corer from a former tin mining lake then analyzed using alpha-spectrometry and Neutron Activation Analysis (NAA). From this study, the results showed the sedimentation rate for sediment cores S1 and S2 are 0.26 cm y -1 and 0.23 cmy -1 respectively. According to sediment chronological sequences, high concentrations of As and Zn in the upper layer indicated that human activities contributed to these metals contamination in the lake sediment. Sedimentation rate and metals contamination possibly due to recent anthropogenic activities around the lake such as human settlement, farming and agricultures activities since the ceased of mining activities a few decades ago. (author)

  6. Applications of the Regional Atmospheric Modeling System (RAMS) to provide input to photochemical grid models for the Lake Michigan Ozone Study (LMOS)

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, W.A.; Tremback, C.J.; Pielke, R.A. [ASTeR, Inc., Ft. Collins, CO (United States); Eastman, J.L. [Colorado State Univ., Ft. Collins, CO (United States)

    1994-12-31

    In spite of stringent emission controls, numerous exceedances of the US ozone air quality standard have continued in the Lake Michigan region, especially during the very hot summers of 1987 and 1988. Analyses revealed that exceedances of the 120 PPB hourly standard were 400% more likely at monitors located within 20 km of the lakeshore. While the role of Lake Michigan in exacerbating regional air quality problems has been investigated for almost 20 years, the relative impacts of various phenomena upon regional photochemical air quality have yet to be quantified. In order to design a defensible regional emission control policy, LMOS sponsored the development of a comprehensive regional photochemical modeling system. This is comprised of an emission model, an advanced regional photochemical model, and a prognostic meteorological model.

  7. Investigation of environmental change on the Tega Lake based on lake sediment analysis. Pt. 2. Dating of sediment by the lead-210/cesium-137 method and environmental change detected by the diatom assemblage analysis

    International Nuclear Information System (INIS)

    Hamada, Takaomi

    1998-01-01

    Sediment collected in the Tega Lake was dated by lead-210/cesium-137 method and environmental change in the Tega Lake was investigated by analysis of diatom remain assemblages in the sediment. Dating of the lead-210/cesium-137 method proved that the surface 30 cm-thickness of sediment in the Tega Lake was deposited during the recent 50 years. Diatom remain assemblage change in the Hon-Tega Lake sediment started in the early half of 1960's and the changes is characterized decrease of Fragilaria construens, that does not prefer to inhabit eutrophic water, and increase of Cyclotella meneghiniana that prefers to inhabit eutrophic water. This diatom assemblage change indicates that the Tega Lake was eutrophicated, and probably suggests water pollution in the Tega Lake. It is detected that influence of residential development around the Tega Lake and reclaiming by drainage on the Tega Lake. (author)

  8. Utilization of diatoms as a food source by calanoid copepods and the abundance and distribution of zoodetritus in southeastern Lake Michigan

    International Nuclear Information System (INIS)

    Ferrante, J.G.

    1975-01-01

    The transfer of material from phytoplankton to zooplankton is important in understanding the movement and cycling of substances in aquatic systems. Since Lake Michigan phytoplankton are predominantly diatoms, their utilization for nutrition by calanoid copepods is an important aspect that is currently being investigated. The contents of fecal pellets were examined with the scanning electron microscope and the diatoms enumerated. Twenty-one species and subspecies of diatoms in eight genera were observed in calanoid pellets

  9. Impacts of flamingos on saline lake margin and shallow lacustrine sediments in the Kenya Rift Valley

    Science.gov (United States)

    Scott, Jennifer J.; Renaut, Robin W.; Owen, R. Bernhart

    2012-11-01

    Studies of modern, Holocene, and Pleistocene sediments around saline to hypersaline, alkaline Lake Bogoria and Lake Magadi show that evidence of flamingo activity in marginal areas of these lakes is nearly ubiquitous. Flamingos produce discrete structures such as webbed footprints (~ 9 cm long, ~ 11 cm wide) and nest mounds (~ 30 cm wide, ~ 20 cm high), and they also extensively rework sediments in delta front, delta plain, and shoreline areas. Large (~ 0.5-2 cm in diameter), pinched, 'bubble pores' and ped-like mud clumps are formed by the trampling and churning of wet clay-rich sediments in these settings. Flamingo nest mounds, although superficially similar to some thrombolite mounds, are typically internally structureless, unless formed on pre-existing sediments that preserve internal structures. The flamingo mounds consist of a dense, packed oval-shaped core, a surrounding 'body' of packed sediment, and an external layer with a ped-like texture of clumped mud. The nests may contain open holes from roots or feather shafts incorporated into the nest, and (or) burrows produced once the nests are abandoned. In areas with high densities of flamingos, lake margin sediments may be preferentially compacted, particularly at breeding sites, and become resistant to subaerial erosion and the effects of transgressive ravinement on time scales ranging from seasons to tens of thousands of years. The relatively well-compacted nest mounds and associated sediments also contribute to the stability of delta distributary channels during regressive-transgressive cycles, and can lead to the minor channelization of unconfined flows where currents are diverted around nest mounds. Pleistocene exhumed surfaces of relatively well-indurated lake margin sediments at Lake Bogoria and Lake Magadi that are interpreted as combined regressive and transgressive surfaces (flooding surface/sequence boundary) preserve evidence of flamingo activities, and are overlain by younger, porous lacustrine

  10. The impact of an urban-industrial region on the magnitude and variability of persistent organic pollutant deposition to Lake Michigan.

    Science.gov (United States)

    Hornbuckle, Keri C; Green, Mark L

    2003-09-01

    A predictive model for gas-phase PCBs and trans-nonachlor over Lake Michigan has been constructed and the resulting data examined for trends. In this paper, we describe the model results to show how the magnitude and variability of a plume of contaminants from the Chicago area contributes to a highly variable region of net contaminant deposition over the entire lake. For the whole lake, gross annual deposition of PCBs is approximately 3200 kg, although the net annual gas exchange is not significantly different from zero. The data-driven model illustrates that on a daily basis, the net exchange of persistent organic pollutants (POPs) can change from net deposition to net volatilization depending on the area of plume impact. These findings suggest that i) control of urban areas can accelerate the rate of volatilization from lakes; and ii) release of POPs from urban areas is largely a result of volatilization processes.

  11. Distribution of metals in fauna, flora and sediments of wet detention ponds and natural shallow lakes

    DEFF Research Database (Denmark)

    Stephansen, D.A.; Nielsen, A.H.; Hvitved-Jacobsen, T.

    2014-01-01

    Fauna, flora, and sediment were collected from 9 wet detention ponds receiving stormwater runoff and 11 small natural shallow lakes. The fauna and flora samples were sorted into species or groups of species and, together with sediments, analyzed for aluminum, copper, iron, zinc, arsenic, cadmium,...

  12. Biogenic elements in bottom sediments of lake Drukshiai - the cooler of Ignalina nuclear power plant

    International Nuclear Information System (INIS)

    Ilgevichiute, J.

    1995-01-01

    The accumulation and distribution of nitrogen, phosphorus, organic carbon, iron and calcium in sediments from different test - places of lake Drukshiai were investigated. The fractional composition of phosphorus and concentration of soluble phosphorus in liquid fraction of sediments and in water were determined. (author). 7 refs., 1 tab., 2 figs

  13. Atmospheric radiocarbon calibration beyond 11,900 cal BP from Lake Suigetsu laminated sediments

    NARCIS (Netherlands)

    Kitagawa, H; van der Plicht, J

    2000-01-01

    This paper presents an updated atmospheric radiocarbon calibration from annually laminated (varved) sediments from Lake Suigetsu (LS). central Japan. As presented earlier, the LS varved sediments can be used to extend the radiocarbon time scale beyond the tree ring calibration range that reaches

  14. Biological and chemical characterization of metal bioavailability in sediments from Lake Roosevelt, Columbia River, Washington, USA

    Science.gov (United States)

    Besser, J.M.; Brumbaugh, W.G.; Ivey, C.D.; Ingersoll, C.G.; Moran, P.W.

    2008-01-01

    We studied the bioavailability and toxicity of copper, zinc, arsenic, cadmium, and lead in sediments from Lake Roosevelt (LR), a reservoir on the Columbia River in Washington, USA that receives inputs of metals from an upstream smelter facility. We characterized chronic sediment toxicity, metal bioaccumulation, and metal concentrations in sediment and pore water from eight study sites: one site upstream in the Columbia River, six sites in the reservoir, and a reference site in an uncontaminated tributary. Total recoverable metal concentrations in LR sediments generally decreased from upstream to downstream in the study area, but sediments from two sites in the reservoir had metal concentrations much lower than adjacent reservoir sites and similar to the reference site, apparently due to erosion of uncontaminated bank soils. Concentrations of acid-volatile sulfide in LR sediments were too low to provide strong controls on metal bioavailability, and selective sediment extractions indicated that metals in most LR sediments were primarily associated with iron and manganese oxides. Oligochaetes (Lumbriculus variegatus) accumulated greatest concentrations of copper from the river sediment, and greatest concentrations of arsenic, cadmium, and lead from reservoir sediments. Chronic toxic effects on amphipods (Hyalella azteca; reduced survival) and midge larvae (Chironomus dilutus; reduced growth) in whole-sediment exposures were generally consistent with predictions of metal toxicity based on empirical and equilibrium partitioning-based sediment quality guidelines. Elevated metal concentrations in pore waters of some LR sediments suggested that metals released from iron and manganese oxides under anoxic conditions contributed to metal bioaccumulation and toxicity. Results of both chemical and biological assays indicate that metals in sediments from both riverine and reservoir habitats of Lake Roosevelt are available to benthic invertebrates. These findings will be used as

  15. Clastic sediment flux to tropical Andean lakes: records of glaciation and soil erosion

    Science.gov (United States)

    Rodbell, Donald T.; Seltzer, Geoffrey O.; Mark, Bryan G.; Smith, Jacqueline A.; Abbott, Mark B.

    2008-08-01

    We developed records of clastic sediment flux to 13 alpine lakes in Peru, Ecuador, and Bolivia, and compared these with independently dated records of regional glaciation. Our objectives are to determine whether a strong relationship exists between the extent of ice cover in the region and the rate of clastic sediment delivery to alpine lakes, and thus whether clastic sediment records serve as reliable proxies for glaciation during the late Pleistocene. We isolated the clastic component in lake sediment cores by removing the majority of the biogenic and authigenic components from the bulk sediment record, and we dated cores by a combination of radiocarbon and tephrochronology. In order to partially account for intra-basin differences in sediment focusing, bedrock erosivity, and sediment availability, we normalized each record to the weighted mean value of clastic sediment flux for each respective core. This enabled the stacking of all 13 lake records to produce a composite record that is generally representative of the tropical Andes. There is a striking similarity between the composite record of clastic sediment flux and the distribution of ˜100 cosmogenic radionuclide (CRN) exposure ages for erratics on moraine crests in the central Peruvian and northern Bolivian Andes. The extent of ice cover thus appears to be the primary variable controlling the delivery of clastic sediment to alpine lakes in the region, which bolsters the increasing use of clastic sediment flux as a proxy for the extent of ice cover in the region. The CRN moraine record and the stacked lake core composite record together indicate that the expansion of ice cover and concomitant increase in clastic sediment flux began at least 40 ka, and the local last glacial maximum (LLGM) culminated between 30 and 20 ka. A decline in clastic sediment flux that began ˜20 ka appears to mark the onset of deglaciation from the LLGM, at least one millennium prior to significant warming in high latitude regions

  16. Factors influencing release of phosphorus from sediments in a high productive polymictic lake system.

    Science.gov (United States)

    Solim, S U; Wanganeo, A

    2009-01-01

    Phosphorus (P) release rates from bottom sediments are high (20.6 mg/m(2)/day) in Dal Lake (India), a polymictic hyper-eutrophic lake. These gross release rates occur over a period of 72 days during summer only. Likewise, a net internal load of 11.3 tons was obtained from mass balance estimates. Significant proportion i.e. approximately 80% of 287.3 tons/yr of nitrate nitrogen (NO(3)-N) load is either eliminated by denitrification or gets entrapped for a short period in high macrophyte biomass of 3.2 kg/m(2) f.w., which eventually get decomposed and nitrogen (N) is released back. These processes result in low lake water NO(3)-N concentrations which potentially influence sediment phosphorus (P) release. Especially, nitrate nitrogen (NO(3)-N) 500 microg/L in the lake waters were associated with high P concentrations. Phosphorus was also observed to increase significantly in relation to temperature and pH, and it seems likely that release of phosphorus and ammonical nitrogen (NH(4)-N) depend on decomposition of rich reserves of organic matter (893 tons d.w. in superficial 10-cm bottom sediment layer). Lake P concentrations were significantly predicted by a multivariate regression model developed for the lake. This study describes significance of various lake water variables in relation to P-release from bottom sediments.

  17. Sediment pollution in margins of the Lake Guaíba, Southern Brazil.

    Science.gov (United States)

    de Andrade, Leonardo Capeleto; Tiecher, Tales; de Oliveira, Jessica Souza; Andreazza, Robson; Inda, Alberto Vasconcellos; de Oliveira Camargo, Flávio Anastácio

    2017-12-02

    Sediments are formed by deposition of organic and inorganic particles on depth of water bodies, being an important role in aquatic ecosystems, including destination and potential source of essential nutrients and heavy metals, which may be toxic for living organisms. The Lake Guaíba supplies water for approximately two million people and it is located in the metropolitan region of Porto Alegre, Rio Grande do Sul State, Brazil. Thus, the aim of this study was to evaluate the sediment pollution in the margins of Lake Guaíba in the vicinity of Porto Alegre city. Surface sediment was sampled in 12 sites to assess the concentration of several elements (C, N, P, Fe, Al, Ca, Mg, Na, K, Mn, Ba, Zn, V, Pb, Cu, Cr, Ni, Cd, Mo, and Se) and the mineralogical composition. Sediment in margins of Lake Guaíba presented predominantly (> 95%) sandy fraction in all samples, but with significant differences between evaluated sites. Sediments in the margins of Lake Guaíba showed indications of punctual water pollution with Pb, Cu, Cr, Ni, TOC, TKN, and P, mainly derived from urban streams that flow into the lake. In order to solve these environmental liabilities, public actions should not focus only on Guaíba, but also in the streams that flow into the lake.

  18. Heavy metals in sediments of a large, turbid tropical lake affected by anthropogenic discharges

    Energy Technology Data Exchange (ETDEWEB)

    Rosales-Hoz, L.; Carranza-Edwards, A.; Lopez-Hernandez, M. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Ciencias del Mar y Limnologia

    2000-01-01

    Bottom-water data and trace metal concentration of Cu, Cr, Ni, Pb, Co, Zn, and organic matter in surficial sediment samples from 13 sampling stations of Lake Chapala in Mexico were studied. The lake is turbid with a great amount of flocculated sediments as a result of wind mixing, sediment re-suspension, and Lerma River discharges. Al distribution pattern in sediments was used as an indicator of the Lerma River discharges into Lake Chapala. The highest values of Cu (33.27 ppm), Cr (81.94 ppm), Pb (99.8 ppm), and Zn (149.7 ppm) were detected in sediments near the lake outlet. The bioavailable metal fraction is low for all metals except Pb, which shows 65-93% of the total metal concentration in bioavailable form. The minimum energy zone in the lake was related to organic matter concentration and was located in the SE part of the lake. An analysis of the studied parameters shows two zones: eastern zone (fluvio-deltaic) and central-western zone (lacustrine). (orig.)

  19. Bioassay of Lake Onego bottom sediments toxicity based on their chemical composition and deepwater macrozoobenthos state

    Directory of Open Access Journals (Sweden)

    Kalinkina Nataliya Michailovna

    2017-03-01

    Full Text Available The bioassay of the toxicity of bottom sediments sampled in different areas of Lake Onega was carried out by crustaceans biotesting (Ceriodaphnia affinis Lillijeborg. It was shown that in the most areas of Lake Onega there are non-toxic bottom sediments. Toxic bottom sediments were found in Kondopogskaya Bay, intensively polluted with pulp-and-paper mill wastewaters. For the first time in the deep central part of Lake Onega the area was revealed where the toxic bottom sediments contain a high content of iron, manganese and other trace elements typical for the central areas of the lake. The mapping of the bottom of Lake Onega was accomplished, and three zones were identified based on the analysis of the data concerning the chemical composition of bottom sediments, bioassay toxicity data and the results of the deepwater macrozoobenthos assessment. For each zone the parameters of the main groups of benthos (Amphipoda, Oligochaeta, Chironomidae were defined. The first zone is located in the area of intensive anthropogenic influence (Kondopogskaya Bay, Petrozavodskaya Bay, Povenets Bay, Kizhi Skerries. The second zone is located mostly in the deep part of Petrozavodskaya Bay, where the most intensive development of amphipods is observed. The third area is identified for the first time: it is located in the central deep part of Lake Onega, where the communities of macrozoobenthos are limited by a natural toxic factor.

  20. 33 CFR 165.910 - Security Zones; Captain of the Port Lake Michigan.

    Science.gov (United States)

    2010-07-01

    .... All waters between the Navy Pier and the Jardine Water Filtration Plant shoreward of a line drawn from the southeast corner of the Jardine Water Filtration Plant at 41°53′36″ N, 87°36′10″ W, to the... Jardine Water Filtration Plant back to the beginning. (ii) Regulations. The Captain of the Port Lake...

  1. Assessment of lake sturgeon (Acipenser fulvescens) spawning efforts in the lower St. Clair River, Michigan

    Science.gov (United States)

    Nichols, S. Jerrine; Kennedy, Gregory; Crawford, Eric; Allen, Jeffrey; French, John; Black, Glen; Blouin, Marc; Hickey, James P.; Chernyak, Sergei; Haas, Robert; Thomas, Michael

    2003-01-01

    One of the most threatened remaining populations of lake sturgeon in the Great Lakes is found in the connecting channels between Lake Huron and Lake Erie. Only two spawning grounds are presently known to be active in this region, and both are in the St. Clair River. The spawning reef in the St. Clair River delta has been recently colonized by round gobies (Neogobius melanostomus) in densities up to 25/m2, raising concerns regarding predation on the benthic-oriented eggs and larvae of the sturgeon. Investigations in 1998–1999 showed that while round goby predation does occur, a number of other factors may be equally affecting sturgeon spawning success, including few spawning adults (noted in either year. There were factors other than predation affecting larval survival in 1999. There was a higher silt load on the reef than in 1998 and large numbers of dead larvae were found. Recruitment success from this site could be improved by utilizing techniques to increase the number of eggs on the reef, such as reducing the illegal take of adult fish and by placing eggs in predator-exclusion chambers to increase hatch rate.

  2. A 500 year sediment lake record of anthropogenic and natural inputs to Windermere (English Lake District) using double-spike lead isotopes, radiochronology, and sediment microanalysis.

    Science.gov (United States)

    Miller, Helen; Croudace, Ian W; Bull, Jonathan M; Cotterill, Carol J; Dix, Justin K; Taylor, Rex N

    2014-07-01

    A high-resolution record of pollution is preserved in recent sediments from Windermere, the largest lake in the English Lake District. Data derived from X-ray core scanning (validated against wavelength dispersive X-ray fluorescence), radiochronological techniques ((210)Pb and (137)Cs) and ultrahigh precision, double-spike mass spectrometry for lead isotopes are combined to decipher the anthropogenic inputs to the lake. The sediment record suggests that while most element concentrations have been stable, there has been a significant increase in lead, zinc, and copper concentrations since the 1930s. Lead isotope down-core variations identify three major contributory sources of anthropogenic (industrial) lead, comprising gasoline lead, coal combustion lead (most likely source is coal-fired steam ships), and lead derived from Carboniferous Pb-Zn mineralization (mining activities). Periods of metal workings do not correlate with peaks in heavy metals due to the trapping efficiency of up-system lakes in the catchment. Heavy metal increases could be due to flood-induced metal inwash after the cessation of mining and the weathering of bedrock in the catchment. The combination of sediment analysis techniques used provides new insights into the pollutant depositional history of Windermere and could be similarly applied to other lake systems to determine the timing and scale of anthropogenic inputs.

  3. Role of organic phosphorus in sediment in a shallow eutrophic lake

    Science.gov (United States)

    Shinohara, Ryuichiro; Hiroki, Mikiya; Kohzu, Ayato; Imai, Akio; Inoue, Tetsunori; Furusato, Eiichi; Komatsu, Kazuhiro; Satou, Takayuki; Tomioka, Noriko; Shimotori, Koichi; Miura, Shingo

    2017-08-01

    We tested the hypothesis that mineralization of molybdenum unreactive phosphorus (MUP) in pore water is the major pathway for the changes in the concentration of molybdenum-reactive P (MRP) in pore water and inorganic P in sediment particles. The concentration of inorganic P in the sediment particles increased from December to April in Lake Kasumigaura, whereas concentrations of organic P in the sediment particles and MUP in pore water decreased. These results suggest that MUP mineralization plays a key role as the source of MRP, whereas desorption of inorganic P from the sediment particles into the pore water is a minor process. One-dimensional numerical simulation of sediment particles and the pore water supported the hypothesis. Diffusive flux of MUP was small in pore water, even in near-surface layers, so mineralization was the dominant process for changing the MUP concentration in the pore water. For MRP, diffusion was the dominant process in the surface layer, whereas adsorption onto the sediment was the dominant process in deeper layers. Researchers usually ignore organic P in the sediment, but organic P in sediment particles and the pore water is a key source of inorganic P in the sediment particles and pore water; our results suggest that in Lake Kasumigaura, organic P in the sediment is an important source, even at depths more than 1 cm below the sediment surface. In contrast, the large molecular size of MUP in pore water hampers diffusion of MUP from the sediment into the overlying water.

  4. Occurance of geophilic of keratinophilic fungi in bottom sediments of lakes of various trophicity

    Directory of Open Access Journals (Sweden)

    Teresa Korniłłowicz

    2014-08-01

    Full Text Available The present investigations proved that colonization of bottom sediments with geophilie kerationophilic fungi in lakes of different trophicity was conditioned by the organic matter content. There was a relationship between occurrence of microorganisms and the basin management method. The greatest concentration of keratinophilic fungi where species typical of sewages polluted with them dominated was found in sediments of a basin used for recreation. In sediments of a lake located in the agricultural region there was a domination of species charakteristic of pure water in respect to sanitary regulations.

  5. Trace elements in sediment samples of the Aswan High Dam Lake

    International Nuclear Information System (INIS)

    Sherief, M.K.; Awadallah, R.M.; Grass, F.

    1981-01-01

    Main and trace elements in Nile sediments of the Aswan High Dam Lake were investigated by means of Instrumental Activation Analysis. It was shown that the composition of the Nile sediments changes in accordance with the large gradients in flow rate and with elution and absorption processes. Particles containing Ca, Ba, Hf, Ti, V, and Na are sedimented preferentially near the headwater of Lake Nubia, whereas some elements are rather uniformly distributed, e.g. Fe, Co, Sm, and Eu, and some, such as Al, Sc, Cs, Th, La, and Ce, show a distinct increase downstream. Some elements do not fit into any of these three groups. (author)

  6. Spatial distribution and source apportionment of PFASs in surface sediments from five lake regions, China

    Science.gov (United States)

    Qi, Yanjie; Huo, Shouliang; Xi, Beidou; Hu, Shibin; Zhang, Jingtian; He, Zhuoshi

    2016-03-01

    Perfluoroalkyl substances (PFASs) have been found in environment globally. However, studies on PFAS occurrence in sediments of lakes or reservoirs remain relatively scarce. In this study, two hundred and sixty-two surface sediment samples were collected from forty-eight lakes and two reservoirs all over China. Average PFAS concentrations in surface sediments from each lake or reservoir varied from 0.086 ng/g dw to 5.79 ng/g dw with an average of 1.15 ng/g dw. Among five lake regions, average PFAS concentrations for the lakes from Eastern Plain Region were the highest. Perfluorooctanoic acid, perfluoroundecanoic acid and perfluorooctane sulfonic acid (PFOS) were the predominant PFASs in surface sediments. The significant positive correlations between PFAS concentrations and total organic carbon, total nitrogen and total phosphorus contents in sediments revealed the influences of sedimentary characteristics on PFAS occurrence. A two-dimensional hierarchical cluster analysis heat map was depicted to analyze the possible origins of sediments and individual PFAS. The food-packaging, textile, electroplating, firefighting and semiconductor industry emission sources and the precious metals and coating industry emission sources were identified as the main sources by two receptor models, with contributions of 77.7 and 22.3% to the total concentrations of C4-C14- perfluoroalkyl carboxylic acids and PFOS, respectively.

  7. Spatial distribution and source apportionment of PFASs in surface sediments from five lake regions, China.

    Science.gov (United States)

    Qi, Yanjie; Huo, Shouliang; Xi, Beidou; Hu, Shibin; Zhang, Jingtian; He, Zhuoshi

    2016-03-07

    Perfluoroalkyl substances (PFASs) have been found in environment globally. However, studies on PFAS occurrence in sediments of lakes or reservoirs remain relatively scarce. In this study, two hundred and sixty-two surface sediment samples were collected from forty-eight lakes and two reservoirs all over China. Average PFAS concentrations in surface sediments from each lake or reservoir varied from 0.086 ng/g dw to 5.79 ng/g dw with an average of 1.15 ng/g dw. Among five lake regions, average PFAS concentrations for the lakes from Eastern Plain Region were the highest. Perfluorooctanoic acid, perfluoroundecanoic acid and perfluorooctane sulfonic acid (PFOS) were the predominant PFASs in surface sediments. The significant positive correlations between PFAS concentrations and total organic carbon, total nitrogen and total phosphorus contents in sediments revealed the influences of sedimentary characteristics on PFAS occurrence. A two-dimensional hierarchical cluster analysis heat map was depicted to analyze the possible origins of sediments and individual PFAS. The food-packaging, textile, electroplating, firefighting and semiconductor industry emission sources and the precious metals and coating industry emission sources were identified as the main sources by two receptor models, with contributions of 77.7 and 22.3% to the total concentrations of C4-C14- perfluoroalkyl carboxylic acids and PFOS, respectively.

  8. The sediment accumulation rates measured in Lake Poyang using 210Pb dating method

    International Nuclear Information System (INIS)

    Wang Xiuyu; Zeng Erkang; Wan Yusong; Liu Xiaosong

    1987-01-01

    The sediment accumulation rates were estimated from the vertical distribution of excess 210 Pb measured in sediment cores collected from Lake Poyang, Jiangxi Provence of China. These rates were various with the differences in hydrology. The sedimentation rates are the lowest in the middle region of the lake, in which the rates could not be determined from the two samples and the other one is 0.14 cm/a. The sedimentation rates are lower in the northeast basin section, averaging to 0.19 cm/a. The sediment rates in the diffusion area of the lake from which 5 rivers enter sand deposion is more than the rates in other areas of the lake (0.08 cm/a to 0.28 cm/a) and the hydrology factors are various. Because of the sand from the Yangzhi River the sedimentation rates are the highest in the water-way section of the lake, averaging from 0.23 to 0.62 cm/a

  9. Historical analysis of salmon-derived polychlorinated biphenyls (PCBs) in lake sediments

    International Nuclear Information System (INIS)

    Kruemmel, Eva M.; Scheer, Michael; Gregory-Eaves, Irene; Macdonald, Robie W.; Kimpe, Lynda E.; Smol, John P.; Finney, Bruce; Blais, Jules M.

    2009-01-01

    Several recent studies have highlighted the importance of salmon as a means to deliver biomagnifying contaminants to nursery lakes. There is a lack of studies, however, which demonstrate empirically how this source has varied through time. This is of great significance because past salmon-derived contaminant loading was potentially greater than it is today. By analyzing radiometrically dated sediment cores collected from ten lakes in Alaska and British Columbia (B.C.), we relate historical numbers of sockeye salmon spawners to ΣPCB concentrations and δ 15 N values (a paleolimnological proxy for past salmon-derived nitrogen) in the sediments. The results confirm that sockeye salmon have provided an important route for PCBs to enter the lakes in the past, a finding that is especially evident when the data of all lakes are pooled. Significant relationships between sockeye salmon numbers and δ 15 N, as well as ΣPCB concentrations and δ 15 N in sediments, were also found. However, it is difficult to establish relationships between salmon numbers, ΣPCBs and δ 15 N in individual lakes. This may be due to a number of factors which may influence contaminant loadings to the lakes. The factors include: a) changing salmon contaminant loads over time resulting from a lag in the upper ocean reservoir and/or changing salmon feeding locations; b) greater importance of atmospheric transport in lakes with relatively low salmon returns; and c) increased PCB scavenging due to higher algae productivity in the lakes in recent years

  10. Sources and sinks of microplastics in Canadian Lake Ontario nearshore, tributary and beach sediments.

    Science.gov (United States)

    Ballent, Anika; Corcoran, Patricia L; Madden, Odile; Helm, Paul A; Longstaffe, Fred J

    2016-09-15

    Microplastics contamination of Lake Ontario sediments is investigated with the aim of identifying distribution patterns and hotspots in nearshore, tributary and beach depositional environments. Microplastics are concentrated in nearshore sediments in the vicinity of urban and industrial regions. In Humber Bay and Toronto Harbour microplastic concentrations were consistently >500 particles per kg dry sediment. Maximum concentrations of ~28,000 particles per kg dry sediment were determined in Etobicoke Creek. The microplastic particles were primarily fibres and fragments microplastics in terms of how and where to implement preventative measures to reduce the contaminant influx. Although the impacts of microplastics contamination on ecosystem health and functioning is uncertain, understanding, monitoring and preventing further microplastics contamination in Lake Ontario and the other Great Lakes is crucial. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Rock magnetic properties of sediments from Lake Sanabria and its catchment (NW Spain): paleoenvironmental implications

    Science.gov (United States)

    Larrasoaña, J. C.; Borruel, V.; Gómez-Paccard, M.; Rico, M.; Valero-Garces, B.; Moreno-Caballud, A.; Soto, R.

    2013-12-01

    Lake Sanabria is located in the NW Spanish mountains at 1000 m a.s.l., and constitutes the largest lake of glacial origin in the Iberian Peninsula. Here we present an environmental magnetic study of a Late Pleistocene-Holocene sediment core from Lake Sanabria and from different lithologies that crop out in its catchment, which includes Paleozoic plutonic, metamorphic and vulcanosedimentary rocks, and Quaternary deposits of glacial origin. This study was designed to complement sedimentologic and geochemical studies aimed at unraveling the climatic evolution of the NW Iberian Peninsula during the last deglaciation. Our results indicate that magnetite and pyrrhotite dominate the magnetic assemblage of both the sediments from the lower half of the studied sequence (25.6 - 13 cal kyr BP) deposited in a proglacial environment, and the Paleozoic rocks that make up most of the catchment of the lake. The occurrence of these minerals both in the catchment rocks and in the lake sediments indicates that sedimentation was then driven by the erosion of a glacial flour, which suffered minimal chemical transformation in response to a rapid and short routing to the lake. Sediments from the upper half of the studied sequence, accumulated after 12.4 cal kyr BP in a fluviolacustrine environment, contain magnetite and greigite. This points to a prominent role of post-depositional reductive dissolution, driven by a sharp increase in the accumulation of organic matter into the lake and the creation of anoxic conditions in the sediments, in shaping the magnetic assemblage of Holocene sediments. Pyrrhotite is stable under reducing conditions as opposed to magnetite, which is unstable. We therefore interpret that previous pedogenic processes occurred in the then deglaciated catchment of the lake were responsible for the oxidation of pyrrhotite and authigenic formation of magnetite, which survived subsequent reductive diagenesis given its initial larger concentrations. This interpretation is

  12. Magnetic Signature of Glacial Flour in Sediments From Bear Lake, Utah/Idaho

    Science.gov (United States)

    Rosenbaum, J. G.; Dean, W. E.; Colman, S. M.; Reynolds, R. L.

    2002-12-01

    Variations in magnetic properties within an interval of Bear Lake sediments correlative with oxygen isotope stage 2 (OIS 2) and OIS 3 provide a record of glacial flour production for the Uinta Mountains. Like sediments of the same age from Upper Klamath Lake (OR), these Bear Lake sediments have high magnetic susceptibilities (MS) relative to non-glacial-age sediments and contain well-defined millennial-scale variations in magnetic properties. In contrast to glacial flour derived from volcanic rocks surrounding Upper Klamath Lake, glacial flour derived from the Uinta Mountains and deposited in Bear Lake by the Bear River has low magnetite content but high hematite content. The relatively low MS values of younger and older non-glacial-age sediments are due entirely to dilution by non-magnetic endogenic carbonate and to the effects of sulfidic alteration of detrital Fe-oxides. Analysis of samples from streams entering Bear Lake and from along the course of the Bear River demonstrates that, in comparison to other areas of the catchment, sediment derived from the Uinta Mountains is rich in hematite (high HIRM) and aluminum, and poor in magnetite (low MS) and titanium. Within the glacial-age lake sediments, there are strong positive correlations among HIRM, Al/Ti, and fine sediment grain size. MS varies inversely with theses three variables. These relations indicate that the observed millennial-scale variations in magnetic and chemical properties arise from varying proportions of two detrital components: (1) very fine-grained glacial flour derived from Proterozoic metasedimentary rocks in the Uinta Mountains and characterized by high HIRM and low MS, and (2) somewhat coarser material, characterized by higher MS and lower HIRM, derived from widespread sedimentary rocks along the course of the Bear River and around Bear Lake. Measurement of glacial flour incorporated in lake sediments can provide a continuous history of alpine glaciation, because the rate of accumulation

  13. A preliminary study on sedimentation rate in Tasek Bera Lake estimated using Pb-210 dating technique

    International Nuclear Information System (INIS)

    Wan Zakaria Wan Muhamad Tahir; Johari Abdul Latif; Juhari Mohd Yusof; Kamaruzaman Mamat; Gharibreza, M.R.

    2010-01-01

    Tasek Bera is the largest natural lake system (60 ha) in Malaysia located in southwest Pahang. The lake is a complex dendritic system consisting of extensive peat-swamp forests. The catchment was originally lowland dipterocarp forest, but this has nearly over the past four decades been largely replaced with oil palm and rubber plantations developed by the Federal Land Development Authority (FELDA). Besides the environmentally importance of Tasek Bera, it is seriously subjected to erosion, sedimentation and morphological changes. Knowledge and information of accurate sedimentation rate and its causes are of utmost importance for appropriate management of lakes and future planning. In the present study, environmental 210 Pb (natural) dating technique was applied to determine sedimentation rate and pattern as well as the chronology of sediment deposit in Tasek Bera Lake. Three undisturbed core samples from different locations at the main entry and exit points of river mouth and in open water within the lake were collected during a field sampling campaign in October 2009 and analyzed for 210 Pb using gamma spectrometry method. Undisturbed sediments are classified as organic soils to peat with clayey texture that composed of 93 % clay, 5 % silt, and 2 % very fine sand. Comparatively higher sedimentation rates in the entry (0.06-1.58 cm/ yr) and exit (0.05-1.55 cm/ yr) points of the main river mouth as compared to the lakes open water (0.02- 0.74 cm/ yr) were noticed. Reasons for the different pattern of sedimentation rates in this lake and conclusion are discussed in this paper. (author)

  14. Reconstruction of historical atmospheric Pb using Dutch urban lake sediments: A Pb isotope study

    Energy Technology Data Exchange (ETDEWEB)

    Walraven, N., E-mail: n.walraven@geoconnect.nl [GeoConnect, Meester Dekkerstraat 4, 1901 PV Castricum (Netherlands); Os, B.J.H. van, E-mail: b.vanos@rce.nl [Rijksdienst voor Archeologie, Cultuurlandschap en Monumenten, P.O. Box 1600, 3800 BP Amersfoort (Netherlands); Klaver, G.Th., E-mail: g.klaver@brgm.nl [BRGM, 3 avenue Claude-Guillemin, BP 36009, 45060 Orléans Cedex 2 (France); Middelburg, J.J., E-mail: j.b.m.middelburg@uu.nl [University Utrecht, Faculty of Geosciences, P.O. Box 80021, 3508 TA Utrecht (Netherlands); Davies, G.R., E-mail: g.r.davies@vu.nl [VU University Amsterdam, Faculty of Earth and Life Sciences, Petrology, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)

    2014-06-01

    Lake sediments provide a record of atmospheric Pb deposition and changes in Pb isotope composition. To our knowledge, such an approach has not previously been performed in The Netherlands or linked to national air monitoring data. Results are presented for Pb content and isotope composition of {sup 137}Cs dated lake sediments from 2 Dutch urban lakes. Between 1942 and 2002 A.D. anthropogenic atmospheric Pb deposition rates in the two lakes varied from 12 ± 2 to 69 ± 16 μg cm{sup −2} year{sup −1}. The rise and fall of leaded gasoline is clearly reflected in the reconstructed atmospheric Pb deposition rates. After the ban on leaded gasoline, late 1970s/early 1980s, atmospheric Pb deposition rates decreased rapidly in the two urban lakes and the relative contributions of other anthropogenic Pb sources — incinerator ash (industrial Pb) and coal/galena — increased sharply. Atmospheric Pb deposition rates inferred from the lake record a clear relationship with nearby measured annual mean air Pb concentrations. Based on this relationship it was estimated that air Pb concentrations between 1942 and 2002 A.D. varied between 5 and 293 ng/m{sup 3}. - Highlights: • Sixty years of atmospheric Pb was reconstructed using urban lake sediments. • Stable Pb isotopes were applied to determine Pb sources in urban lakes. • The rise and fall of leaded gasoline is clearly reflected in the lake sediments. • Other dominant anthropogenic Pb sources are incinerator ash and coal/galena. • The lake Pb record shows a clear relationship with measured air Pb concentrations.

  15. Multi-scale temporal and spatial variation in genotypic composition of Cladophora-borne Escherichia coli populations in Lake Michigan.

    Science.gov (United States)

    Badgley, Brian D; Ferguson, John; Vanden Heuvel, Amy; Kleinheinz, Gregory T; McDermott, Colleen M; Sandrin, Todd R; Kinzelman, Julie; Junion, Emily A; Byappanahalli, Muruleedhara N; Whitman, Richard L; Sadowsky, Michael J

    2011-01-01

    High concentrations of Escherichia coli in mats of Cladophora in the Great Lakes have raised concern over the continued use of this bacterium as an indicator of microbial water quality. Determining the impacts of these environmentally abundant E. coli, however, necessitates a better understanding of their ecology. In this study, the population structure of 4285 Cladophora-borne E. coli isolates, obtained over multiple three day periods from Lake Michigan Cladophora mats in 2007-2009, was examined by using DNA fingerprint analyses. In contrast to previous studies that have been done using isolates from attached Cladophora obtained over large time scales and distances, the extensive sampling done here on free-floating mats over successive days at multiple sites provided a large dataset that allowed for a detailed examination of changes in population structure over a wide range of spatial and temporal scales. While Cladophora-borne E. coli populations were highly diverse and consisted of many unique isolates, multiple clonal groups were also present and accounted for approximately 33% of all isolates examined. Patterns in population structure were also evident. At the broadest scales, E. coli populations showed some temporal clustering when examined by year, but did not show good spatial distinction among sites. E. coli population structure also showed significant patterns at much finer temporal scales. Populations were distinct on an individual mat basis at a given site, and on individual days within a single mat. Results of these studies indicate that Cladophora-borne E. coli populations consist of a mixture of stable, and possibly naturalized, strains that persist during the life of the mat, and more unique, transient strains that can change over rapid time scales. It is clear that further study of microbial processes at fine spatial and temporal scales is needed, and that caution must be taken when interpolating short term microbial dynamics from results obtained

  16. Reconstructing geomorphic patterns and forcing factors from Alpine Lake Sediment

    Science.gov (United States)

    Arnaud, Fabien; Poulenard, Jérôme; Giguet-Covex, Charline; Wilhelm, Bruno; Révillon, Sidonie; Jenny, Jean-Philippe; Revel, Marie; Enters, Dirk; Bajard, Manon; Fouinat, Laurent; Doyen, Elise; Simonneau, Anaëlle; Pignol, Cécile; Chapron, Emmanuel; Vannière, Boris; Sabatier, Pierre

    2017-04-01

    In this paper we review the scientific efforts that were led over the last decades to reconstruct geomorphic patterns from continuous alpine lake sediment records. Whereas our results point a growing importance of humans as erosion forcing factors, we will focus here on climate-related processes. Our main dataset is made of a regional approach which was led without any a priori regarding erosion forcing factors. We hence integrated a set of sediment sequences from various environment along an altitudinal gradient from 200 up to 2400m asl in Northern French Alps. Altogether our data point climate change as one of the main factor of erosion variability. In particular, the last two cold spells that occurred during the early middle age (Dark Age) and between the 14th and the 20th century AD (Little Ice Age) appear to be outstanding compared to any other periods of enhanced erosion along the Holocene. The climatic forcing of those erosion phases is supported by an increase in the contribution of glacier-eroded material at a regional scale. At local scales, our data also point the growing importance, since at least the mid Bronze Age (ca. 3500 cal. BP) of human activities as a major erosion factor. This influence peaked during the late Iron Age and Antiquity periods (200 BC - 400 AD) when we record a regional generalised period of enhanced erosion in response to the development of pasturing activities. Thanks to provenance and weathering markers, we evidenced a strong relationship between the changes in ecosystems, soil development and erosion patterns. We hence showed the vegetal colonisation of bared soil led to a period of intense weathering while new soils were under formation between 11,000 and 8,000 cal. BP. Soils then knew an optimum until the onset of the Neoglacial at ca. 4,500 cal. BP prior to decline under both climate and human pressures. Altogether our data point the complexity of processes that affected the Earth critical zone along the Holocene. However

  17. Environmental magnetic methods for detecting and mapping contaminated sediments in lakes

    Science.gov (United States)

    Boyce, J. I.

    2009-05-01

    The remediation of contaminated sediments is an urgent environmental priority in the Great Lakes and requires detailed mapping of impacted sediment layer thickness, areal distribution and pollutant levels. Magnetic property measurements of sediment cores from two heavily polluted basins in Lake Ontario (Hamilton Harbour, Frenchman's Bay) show that concentrations of hydrocarbons (PAH) and a number of heavy metals (Pb, As, Ni, Cu, Cr, Zn, Cd, Fe) are strongly correlated with magnetic susceptibility. The magnetic susceptibility contrast between the contaminated sediment and underlying 'pre-colonial' sediments is sufficient to generate a total field anomaly (ca. 2-20 nT) that can be measured with a magnetometer towed above the lake bed. Systematic magnetic surveying (550 line km) of Hamilton Harbour using a towed marine magnetometer clearly identifies a number of well-defined magnetic anomalies that coincide with known accumulations of contaminated lake sediment. When calibrated against in-situ magnetic property measurements, the modeled apparent susceptibility from magnetic survey results can be used to classify the relative contaminant impact levels. The results demonstrate the potential of magnetic property measurements for rapid reconnaissance mapping of large areas of bottom contamination prior to detailed coring and sediment remediation.

  18. Ancient DNA from lake sediments: Bridging the gap between paleoecology and genetics

    Directory of Open Access Journals (Sweden)

    Lumibao Candice Y

    2011-01-01

    Full Text Available Abstract Background Quaternary plant ecology in much of the world has historically relied on morphological identification of macro- and microfossils from sediments of small freshwater lakes. Here, we report new protocols that reliably yield DNA sequence data from Holocene plant macrofossils and bulk lake sediment used to infer ecological change. This will allow changes in census populations, estimated from fossils and associated sediment, to be directly associated with population genetic changes. Results We successfully sequenced DNA from 64 samples (out of 126 comprised of bulk sediment and seeds, leaf fragments, budscales, and samaras extracted from Holocene lake sediments in the western Great Lakes region of North America. Overall, DNA yields were low. However, we were able to reliably amplify samples with as few as 10 copies of a short cpDNA fragment with little detectable PCR inhibition. Our success rate was highest for sediments Conclusions An ability to extract ancient DNA from Holocene sediments potentially allows exciting new insights into the genetic consequences of long-term environmental change. The low DNA copy numbers we found in fossil material and the discovery of multiple sequence variants from single macrofossil extractions highlight the need for careful experimental and laboratory protocols. Further application of these protocols should lead to better understanding of the ecological and evolutionary consequences of environmental change.

  19. Temporal and spatial variations in kinetics of alkaline phosphatase in sediments of a shallow Chinese eutrophic lake (Lake Donghu).

    Science.gov (United States)

    Yiyong, Zhou; Jianqiu, Li; Min, Zhang

    2002-04-01

    Monthly sediment and interstitial water samples were collected in a shallow Chinese freshwater lake (Lake Donghu) from three areas to determine if alkaline phosphatase activity (APA) plays an important role, in phosphorus cycling in sediment. The seasonal variability in the kinetics of APA and other relevant parameters were investigated from 1995-1996. The phosphatase hydrolyzable phosphorus (PHP) fluctuated seasonally in interstitial water, peaking in the spring. A synchronous pattern was observed in chlorophyll a contents in surface water in general. The orthophosphate (o-P) concentrations in the interstitial water increased during the spring. An expected negative relationship between PHP and Vmax of APA is not evident in interstitial water. The most striking feature of the two variables is their co-occurring, which can be explained in terms of an induction mechanism. It is argued that phosphatase activity mainly contributes to the driving force of o-P regeneration from PHP in interstitial water, supporting the development of phytoplankton biomass in spring. The Vmax values in sediment increased during the summer, in conjunction with lower Km values in interstitial water that suggest a higher affinity for the substrate. The accumulation of organic matter in the sediment could be traced back to the breakdown of the algal spring bloom, which may stimulate APA with higher kinetic efficiency, by a combination of the higher Vmax in sediments plus lower Km values in interstitial water, in summer. In summary, a focus on phosphatase and its substrate in annual scale may provide a useful framework for the development of novel P cycling, possible explanations for the absence of a clear relationship between PHP and APA were PHP released from the sediment which induced APA, and the presence of kinetically higher APA both in sediment and interstitial water which permitted summer mineralization of organic matter derived from the spring bloom to occur. The study highlighted the

  20. Diversity analysis of bacterial community compositions in sediments of urban lakes by terminal restriction fragment length polymorphism (T-RFLP).

    Science.gov (United States)

    Zhao, Dayong; Huang, Rui; Zeng, Jin; Yan, Wenming; Wang, Jianqun; Ma, Ting; Wang, Meng; Wu, Qinglong L

    2012-11-01

    Bacteria are crucial components in lake sediments and play important role in various environmental processes. Urban lakes in the densely populated cities are often small, shallow, highly artificial and hypereutrophic compared to rural and natural lakes and have been overlooked for a long time. In the present study, bacterial community compositions in surface sediments of three urban lakes (Lake Mochou, Lake Qianhu and Lake Zixia) in Nanjing City, China, were investigated using the terminal restriction fragment length polymorphism (T-RFLP) of PCR-amplified 16S rRNA gene and clone libraries. Remarkable differences in the T-RFLP patterns were observed in different lakes or different sampling stations of the same lake. Canonical correspondence analysis indicated that total nitrogen (TN) had significant effects on bacterial community structure in the lake sediments. Chloroflexi were the most dominant bacterial group in the clone library from Lake Mochou (21.7 % of the total clones) which was partly associated with its higher TN and organic matters concentrations. However, Bacteroidetes appeared to be dominated colonizers in the sediments of Lake Zixia (20.4 % of the total clones). Our study gives a comprehensive insight into the structure of bacterial community of urban lake sediments, indicating that the environmental factors played a key role in influencing the bacterial community composition in the freshwater ecosystems.

  1. Origin of fin-clipped salmonids collected at two thermal discharges on Lake Michigan

    International Nuclear Information System (INIS)

    Romberg, G.P.; Thommes, M.M.; Spigarelli, S.A.

    1974-01-01

    Fin clips observed on fish collected during tagging studies at the Point Beach and Waukegan thermal discharges were recorded and the data were tabulated by species. Using fin clip and fish size, attempts were made to identify probable stocking locations and dates from agency records. Data are presented for lake trout, rainbow trout, brown trout, and Coho salmon. Tables are presented to show probable stocking locations and dates

  2. Wave Height and Water Level Variability on Lakes Michigan and St Clair

    Science.gov (United States)

    2012-10-01

    Observations: http://www.ssec.wisc.edu/sose/glwx_activity.html 4. NASA Atlas of Extratropical Storm Tracks: http://data.giss.nasa.gov/stormtracks...term meteorological, ice, wave, and water level measurements. 15. SUBJECT TERMS Base flood elevation Coastal flood Extratropical storms Great...Box 1027 Detroit, MI 48231-1027 ERDC/CHL TR-12-23 ii Abstract The Great Lakes are subject to coastal flooding as a result of severe storms

  3. Drought drove forest decline and dune building in eastern upper Michigan, USA, as the upper Great Lakes became closed basins

    Science.gov (United States)

    Loope, Walter L.; Loope, Henry M.; Goble, Ronald J.; Fisher, Timothy G.; Lytle, David E.; Legg, Robert J.; Wysocki, Douglas A.; Hanson, Paul R.; Young, Aaron R.

    2012-01-01

    Current models of landscape response to Holocene climate change in midcontinent North America largely reconcile Earth orbital and atmospheric climate forcing with pollen-based forest histories on the east and eolian chronologies in Great Plains grasslands on the west. However, thousands of sand dunes spread across 12,000 km2 in eastern upper Michigan (EUM), more than 500 km east of the present forest-prairie ecotone, present a challenge to such models. We use 65 optically stimulated luminescence (OSL) ages on quartz sand deposited in silt caps (n = 8) and dunes (n = 57) to document eolian activity in EUM. Dune building was widespread ca. 10–8 ka, indicating a sharp, sustained decline in forest cover during that period. This decline was roughly coincident with hydrologic closure of the upper Great Lakes, but temporally inconsistent with most pollen-based models that imply canopy closure throughout the Holocene. Early Holocene forest openings are rarely recognized in pollen sums from EUM because faint signatures of non-arboreal pollen are largely obscured by abundant and highly mobile pine pollen. Early Holocene spikes in nonarboreal pollen are recorded in cores from small ponds, but suggest only a modest extent of forest openings. OSL dating of dune emplacement provides a direct, spatially explicit archive of greatly diminished forest cover during a very dry climate in eastern midcontinent North America ca. 10–8 ka.

  4. Late Holocene Hydrologic Variability in the southeast Mojave Desert using sediments from Ford Lake, California

    Science.gov (United States)

    Leidelmeijer, J.; Kirby, M.; Anderson, W. T., Jr.; Mayer, S. A.; Palermo, J. A.; Stout, C.; Shellhorn, A.; Weisberg, G.; Rangel, H.; Hess, B.

    2017-12-01

    Most published lacustrine studies located in the Mojave Desert focus on lakes that receive the majority of their water from the Mojave River (e.g., Silver Lake, Cronese Lakes, Soda Lake, etc). Consequently, these Mojave River-fed lake sites record coastal hydroclimatic signals rather than a solely Mojave-only signal. The reason for this signal-disconnect is that the Mojave River is sourced in the San Bernardino Mountains, where annual precipitation is dictated by coastal hydroclimates. Therefore, much remains unknown about how the Mojave Desert changed during the Holocene at sub-millennial time scales. To address this problem and fill in an important geographical gap, we focus on Ford Lake in the southeastern Mojave Desert. Ford Lake is an internally drained, closed basin, and it is completely disconnected from the Mojave River. As a result, it represents one of the first lakes studied in the Mojave Desert with a climate signal that is 100% Mojave. Sediments from Ford Lake provide valuable context for understanding hydroclimatic variability exclusive to the Mojave Desert. To date, two hand-dug 1.5 m trenches (depocenter and littoral zone) and 3 overlapping sediments cores from the lake's depocenter have been sampled. The total core length is 3.55 m and bottomed in coarse alluvium, suggesting we captured the complete lacustrine sediment package. Initial results by Mayer (2016) focused on the most recent 1200 calendar years before present, or the upper 2.16 m. Mayer (2016) found evidence for increased run-off (wetter climate) during the Little Ice Age and reduced run-off (drier climate) during the Medieval Climatic Anomaly. Here, we complete the study, improving age control using sediment charcoal. Grain size, magnetic susceptibility, percent total organic matter, percent total carbonate content, C:N ratios and C and N isotopic analyses are (will be) measured at 1 cm contiguous intervals. The Ford Lake record has been (will be) compared to pre-existing regional

  5. Behavior of plutonium and other long-lived radionuclides in Lake Michigan. I. Biological transport, seasonal cycling, and residence times in the water column

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Marshall, J.S.

    1975-01-01

    Eight operating nuclear reactors are situated on the shores of Lake Michigan, but their releases of radioactivity have been much less than that entering the lake from stratospheric fallout. Measurements of 239 , 240 Pu, 241 Am, and 137 Cs from the latter source have been made in order to study biological transport, seasonal cycling, and residence times of long-lived radionuclides in the lake. The apparent turnover times for the residual fallout 239 , 240 Pu and 137 Cs, which are present as nonfilterable, ionic forms, are about 3 to 4 y. Resuspension may be occurring at a low rate, probably through the feeding activities of benthic organisms. Transport by settling of phytodetritus and zooplankton fecal pellets is postulated to be the cause of the rapid decline of the concentration of 239 , 240 Pu in surface waters observed during summer thermal stratification of the lake, while the concentration of 137 Cs remained almost constant. Concentration factors for fallout 239 , 240 Pu, 137 Cs, and 90 Sr at various trophic levels in the food chain in Lake Michigan have been measured. Analyses of biological samples taken at various distances from the Big Rock Point Nuclear Power Plant and of plant waste discharge show that any plutonium possibly released from the recycle plutonium test fuel is too low to be detectable in the presence of fallout plutonium. Measurements of 239 , 240 Pu, 137 Cs, and 90 Sr on a comparison set of surface water and net plankton samples from all five Great Lakes indicate generally consistent behavior patterns in these lakes. (U.S.)

  6. Estimation of sediment sources using selected chemical tracers in the Perry lake basin, Kansas, USA

    Science.gov (United States)

    Juracek, K.E.; Ziegler, A.C.

    2009-01-01

    The ability to achieve meaningful decreases in sediment loads to reservoirs requires a determination of the relative importance of sediment sources within the contributing basins. In an investigation of sources of fine-grained sediment (clay and silt) within the Perry Lake Basin in northeast Kansas, representative samples of channel-bank sources, surface-soil sources (cropland and grassland), and reservoir bottom sediment were collected, chemically analyzed, and compared. The samples were sieved to isolate the phosphorus), organic and total carbon, 25 trace elements, and the radionuclide cesium-137 (137Cs). On the basis of substantial and consistent compositional differences among the source types, total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), and 137Cs were selected for use in the estimation of sediment sources. To further account for differences in particle-size composition between the sources and the reservoir bottom sediment, constituent ratio and clay-normalization techniques were used. Computed ratios included TOC to TN, TOC to TP, and TN to TP. Constituent concentrations (TN, TP, TOC) and activities (137Cs) were normalized by dividing by the percentage of clay. Thus, the sediment-source estimations involved the use of seven sediment-source indicators. Within the Perry Lake Basin, the consensus of the seven indicators was that both channel-bank and surface-soil sources were important in the Atchison County Lake and Banner Creek Reservoir subbasins, whereas channel-bank sources were dominant in the Mission Lake subbasin. On the sole basis of 137Cs activity, surface-soil sources contributed the most fine-grained sediment to Atchison County Lake, and channel-bank sources contributed the most fine-grained sediment to Banner Creek Reservoir and Mission Lake. Both the seven-indicator consensus and 137Cs indicated that channel-bank sources were dominant for Perry Lake and that channel-bank sources increased in importance with distance

  7. The effect of lake sediment on the hatching success of Daphnia ephippial eggs

    Directory of Open Access Journals (Sweden)

    Jacek Radzikowski

    2016-07-01

    Full Text Available A large proportion of lake-Daphnia ephippia which are shed by females in the water column sink to the bottom, where they form an assemblage of dormant stages known as an egg bank. Although the quantity of zooplankton eggs in such assemblages may exceed tens of thousands per square meter, the annual hatch from this bank is usually extremely low (from zero to a few dozens animals per square meter per year. This low-hatching phenomenon may be caused by isolation from hatching stimuli by water or sediment layers, a mechanical barrier formed by sediment that does not allow hatchlings to reach the water, or by a bet-hedging strategy of the resting eggs. The aim of our study was to determine the extent to which coverage by lake sediment may affect the hatching of Daphnia dormant eggs. The ephippia of lake-Daphnia (longispina species complex, covered by sterilized lake sediment of different thicknesses (0, 0.25, 0.5, 1, 2 and 4 cm; 4 replicates per treatment, were incubated for 8 weeks in lab controlled conditions. The results indicate that even the thinnest tested layer (0.25 cm may completely inhibit hatching of ephippial eggs. A few Daphnia neonates were observed in two (of five sediment treatments, while dozens of animals hatched in the control one. In the second experiment we determined that the sediment sterilization process did not affect the hatching proportion of ephippial eggs (when compared to the treatment with unsterilized sediments. We hypothesize that the observed inhibition of Daphnia hatching in the main experiment, which may cause a serious problem for Cladoceran populations in lakes where no sediment mixing occurs, may be caused by low light intensity, anoxic conditions or a physical barrier created by the sediment.

  8. Predicting lake responses to phosphorus loading with measurement-based characterization of P recycling in sediments

    Science.gov (United States)

    Katsev, S.; Li, J.

    2017-12-01

    Predicting the time scales on which lake ecosystems respond to changes in anthropogenic phosphorus loadings is critical for devising efficient management strategies and setting regulatory limits on loading. Internal loading of phosphorus from sediments, however, can significantly contribute to the lake P budget and may delay recovery from eutrophication. The efficiency of mineralization and recycling of settled P in bottom sediments, which is ultimately responsible for this loading, is often poorly known and is surprisingly poorly characterized in the societally important systems such as the Great Lakes. We show that a simple mass-balance model that uses only a minimum number of parameters, all of which are measurable, can successfully predict the time scales over which the total phosphorus (TP) content of lakes responds to changes in external loadings, in a range of situations. The model also predicts the eventual TP levels attained under stable loading conditions. We characterize the efficiency of P recycling in Lake Superior based on a detailed characterization of sediments at 13 locations that includes chemical extractions for P and Fe fractions and characterization of sediment-water exchange fluxes of P. Despite the low efficiency of P remobilization in these deeply oxygenated sediments (only 12% of deposited P is recycled), effluxes of dissolved phosphorus (2.5-7.0 μmol m-2 d-1) still contribute 37% to total P inputs into the water column. In this oligotrophic large lake, phosphate effluxes are regulated by organic sedimentation rather than sediment redox conditions. By adjusting the recycling efficiency to conditions in other Laurentian Great Lakes, we show that the model reproduces the historical data for total phosphorus levels. Analysis further suggests that, in the Lower Lakes, the rate of P sequestration from water column into sediments has undergone a significant change in recent decades, possibly in response to their invasion by quagga mussels

  9. Characterizing the Fate and Mobility of Phosphorus in Utah Lake Sediments

    Science.gov (United States)

    Carling, G. T.; Randall, M.; Nelson, S.; Rey, K.; Hansen, N.; Bickmore, B.; Miller, T.

    2017-12-01

    An increasing number of lakes worldwide are impacted by eutrophication and harmful algal blooms due to anthropogenic nutrient inputs. Utah Lake is a unique eutrophic freshwater lake that is naturally shallow, turbid, and alkaline with high dissolved oxygen levels that has experienced severe algal blooms in recent years. Recently, the Utah Division of Water Quality has proposed a new limitation of phosphorus (P) loading to Utah Lake from wastewater treatment plants in an effort to mitigate eutrophication. However, reducing external P loads may not lead to immediate improvements in water quality due to the legacy pool of nutrients in lake sediments. The purpose of this study was to characterize the fate and mobility of P in Utah Lake sediments to better understand P cycling in this unique system. We analyzed P speciation, mineralogy, and binding capacity in lake sediment samples collected from 15 locations across Utah Lake. P concentrations in sediment ranged from 615 to 1894 ppm, with highest concentrations in Provo Bay near the major metropolitan area. Sequential leach tests indicate that 25-50% of P is associated with Ca (CaCO₃/ Ca10(PO4)6(OH,F,Cl)2 ≈ P) and 40-60% is associated with Fe (Fe(OOH) ≈ P). Ca-associated P was confirmed by SEM images, which showed the highest P concentrations correlating with Ca (carbonate minerals/apatite). The Ca-associated P fraction is likely immobile, but the Fe-bound P is potentially bioavailable under changing redox conditions. Batch sorption results indicate that lake sediments have a high capacity to absorb and remove P from the water column, with an average uptake of 70-96% removal over the range of 1-10 mg/L P. Mineral precipitation and sorption to bottom sediments is an efficient removal mechanism of P in Utah Lake, but a significant portion of P may be temporarily available for resuspension and cycling in surface waters. Mitigating lake eutrophication is a complex problem that goes beyond decreasing external nutrient

  10. Carbon 14, carbon 13 and oxygen 18 in carbonate sediments from lake Titicaca. Preliminary estimates of sedimentation rate and paleoclimatological attempt

    International Nuclear Information System (INIS)

    Fontes, J.-C.; Boulange, Bruno; Rodrigo, L.-A.

    1981-01-01

    Stable isotope and radiocarbon measurements in carbonates from Titicaca lake indicate equilibrium with lake water and atmospheric CO 2 . Average sedimentation rate is close to 0,5 mm.yr -1 for the last millenium which was marked by large fluctuations of the hydrologic balance and lake level [fr

  11. Carbon 14, carbon 13 and oxygen 18 in carbonate sediments from Lake Titicaca. Preliminary estimates of sedimentation rate and paleoclimatological attempt

    Energy Technology Data Exchange (ETDEWEB)

    Fontes, J.C. (Paris-11 Univ., 91 - Orsay (France)); Boulange, B. (Orstom, 75 - Paris (France)); Rodrigo, L.A. (Universidad Mayor de San Andres, La Paz (Bolivia). Lab. de Fisica Cosmica de Chacaltaya)

    1981-07-06

    Stable isotope and radiocarbon measurements in carbonates from Lake Titicaca indicate equilibrium with lake water and atmospheric CO/sub 2/. Average sedimentation rate is close to 0,5 mm.yr/sup -1/ for the last millenium which was marked by large fluctuations of the hydrologic balance and lake level.

  12. Stream Sediment Geochemical Survey of Selected Element In Catchment Area Of Saguling Lake

    Directory of Open Access Journals (Sweden)

    Wardhani Eka

    2018-01-01

    Full Text Available Saguling Lake is one of the largest lakes in West Java Province that accommodates domestic and non-domestic wastes via the Citarum River as its main water source. This study aims to determine the geochemical background concentration (Cbg in water catchment area of Saguling Lake. The knowledge of the Cbg of heavy metals is essential for defining pollution, identifying the source of contamination, and for establishing reliable environmental quality criteria for sediments. The value of Cbg will be used for assessment of the sediment quality in Saguling Lake. Assessment of sediment quality is very important to determine the actual condition of water in the lake and as the basis for management of waters environment in the future. The search was taken at 22 sampling points in the unpolluted water catchment area. Samples were collected and analyzed for Cd, Cr, Cu, and Pb. Each sample was digested in agua regia and analyzed by ICP-EOS. Results showed Cbg which are: Cd 0.34 ± 0.10 mg/kg, Cr 110.57 ± 28.61 mg/kg, Cu 49.93 ± 9.28 mg/kg, and Pb 18.62 ± 9.83 mg/kg. Based on the assessment result, it is concluded that the sediment quality in Saguling Lake is categorized as polluted by Cd, Cr, Cu, and Pb metals.

  13. Comparison of benthos and plankton for selected areas of concern and non-areas of concern in western Lake Michigan Rivers and Harbors in 2012

    Science.gov (United States)

    Eikenberry, Barbara C. Scudder; Bell, Amanda H.; Olds, Hayley T.; Burns, Daniel J.

    2016-07-25

    Recent data are lacking to assess whether impairments still exist at four of Wisconsin’s largest Lake Michigan harbors that were designated as Areas of Concern (AOCs) in the late 1980s due to sediment contamination and multiple Beneficial Use Impairments (BUIs), such as those affecting benthos (macroinvertebrates) and plankton (zooplankton and phytoplankton) communities. During three seasonal sampling events (“seasons”) in May through August 2012, the U.S. Geological Survey collected sediment benthos and water plankton at the four AOCs as well as six less-degraded non-AOCs along the western Lake Michigan shoreline to assess whether AOC communities were degraded in comparison to non-AOC communities. The four AOCs are the Lower Menominee River, the Lower Green Bay and Fox River, the Sheboygan River, and the Milwaukee Estuary. Due to their size and complexity, multiple locations or “subsites” were sampled within the Lower Green Bay and Fox River AOC (Lower Green Bay, the Fox River near Allouez, and the Fox River near De Pere) and within the Milwaukee Estuary AOC (the Milwaukee River, the Menomonee River, and the Milwaukee Harbor) and single locations were sampled at the other AOCs and non-AOCs. The six non-AOCs are the Escanaba River in Michigan, and the Oconto River, Ahnapee River, Kewaunee River, Manitowoc River, and Root River in Wisconsin. Benthos samples were collected by using Hester-Dendy artificial substrates deployed for 30 days and by using a dredge sampler; zooplankton were collected by net and phytoplankton by whole-water sampler. Except for the Lower Green Bay and Milwaukee Harbor locations, communities at each AOC were compared to all non-AOCs as a group and to paired non-AOCs using taxa relative abundances and metrics, including richness, diversity, and an Index of Biotic Integrity (IBI, for Hester-Dendy samples only). Benthos samples collected during one or more seasons were rated as degraded for at least one metric at all AOCs. In the

  14. Tsunami-generated sediment wave channels at Lake Tahoe, California-Nevada, USA

    Science.gov (United States)

    Moore, James G.; Schweickert, Richard A.; Kitts, Christopher A.

    2014-01-01

    A gigantic ∼12 km3 landslide detached from the west wall of Lake Tahoe (California-Nevada, USA), and slid 15 km east across the lake. The splash, or tsunami, from this landslide eroded Tioga-age moraines dated as 21 ka. Lake-bottom short piston cores recovered sediment as old as 12 ka that did not reach landslide deposits, thereby constraining the landslide age as 21–12 ka.Movement of the landslide splashed copious water onto the countryside and lowered the lake level ∼10 m. The sheets of water that washed back into the lake dumped their sediment load at the lowered shoreline, producing deltas that merged into delta terraces. During rapid growth, these unstable delta terraces collapsed, disaggregated, and fed turbidity currents that generated 15 subaqueous sediment wave channel systems that ring the lake and descend to the lake floor at 500 m depth. Sheets of water commonly more than 2 km wide at the shoreline fed these systems. Channels of the systems contain sediment waves (giant ripple marks) with maximum wavelengths of 400 m. The lower depositional aprons of the system are surfaced by sediment waves with maximum wavelengths of 300 m.A remarkably similar, though smaller, contemporary sediment wave channel system operates at the mouth of the Squamish River in British Columbia. The system is generated by turbidity currents that are fed by repeated growth and collapse of the active river delta. The Tahoe splash-induced backwash was briefly equivalent to more than 15 Squamish Rivers in full flood and would have decimated life in low-lying areas of the Tahoe region.

  15. Current status and historical variations of phthalate ester (PAE) contamination in the sediments from a large Chinese lake (Lake Chaohu).

    Science.gov (United States)

    Kang, Lei; Wang, Qing-Mei; He, Qi-Shuang; He, Wei; Liu, Wen-Xiu; Kong, Xiang-Zhen; Yang, Bin; Yang, Chen; Jiang, Yu-Jiao; Xu, Fu-Liu

    2016-06-01

    The residual levels of phthalate esters (PAEs) in the surface and two core sediments from Lake Chaohu were measured with a gas chromatograph-mass spectrometer (GC-MS). The temporal-spatial distributions, compositions of PAEs, and their effecting factors were investigated. The results indicated that di-n-butyl phthalate (DnBP), diisobutyl phthalate (DIBP), and di(2-ethylhexyl) phthalate (DEHP) were three dominant PAE components in both the surface and core sediments. The residual level of total detected PAEs (∑PAEs) in the surface sediments (2.146 ± 2.255 μg/g dw) was lower than that in the western core sediments (10.615 ± 9.733 μg/g) and in the eastern core sediments (5.109 ± 4.741 μg/g). The average content of ∑PAEs in the surface sediments from the inflow rivers (4.128 ± 1.738 μg/g dw) was an order of magnitude higher than those from the lake (0.323 ± 0.093 μg/g dw), and there were similar PAE compositions between the lake and inflow rivers. This finding means that there were important effects of PAE input from the inflow rivers on the compositions and distributions of PAEs in the surface sediments. An increasing trend was found for the residual levels of ΣPAEs, DnBP, and DIBP from the bottom to the surface in both the western and eastern core sediments. Increasing PAE usage with the population growth, urbanization, and industrial and agricultural development in Lake Chaohu watershed would result in the increasing production of PAEs and their resulting presence in the sediments. The significant positive relationships were also found between the PAE contents and the percentage of sand particles, as well as TOC contents in the sediment cores.

  16. Salinity drives archaeal distribution patterns in high altitude lake sediments on the Tibetan Plateau.

    Science.gov (United States)

    Liu, Yongqin; Priscu, John C; Xiong, Jinbo; Conrad, Ralf; Vick-Majors, Trista; Chu, Haiyan; Hou, Juzhi

    2016-03-01

    Archaeal communities and the factors regulating their diversity in high altitude lakes are poorly understood. Here, we provide the first high-throughput sequencing study of Archaea from Tibetan Plateau lake sediments. We analyzed twenty lake sediments from the world's highest and largest plateau and found diverse archaeal assemblages that clustered into groups dominated by methanogenic Euryarchaeota, Crenarchaeota and Halobacteria/mixed euryarchaeal phylotypes. Statistical analysis inferred that salinity was the major driver of community composition, and that archaeal diversity increased with salinity. Sediments with the highest salinities were mostly dominated by Halobacteria. Crenarchaeota dominated at intermediate salinities, and methanogens were present in all lake sediments, albeit most abundant at low salinities. The distribution patterns of the three functional types of methanogens (hydrogenotrophic, acetotrophic and methylotrophic) were also related to changes in salinity. Our results show that salinity is a key factor controlling archaeal community diversity and composition in lake sediments on a spatial scale that spans nearly 2000 km on the Tibetan Plateau. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Modeled tephra ages from lake sediments, base of Redoubt Volcano, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Schiff, C J; Kaufman, D S; Wallace, K L; Werner, A; Ku, T L; Brown, T A

    2007-02-25

    A 5.6-m-long lake sediment core from Bear Lake, Alaska, located 22 km southeast of Redoubt Volcano, contains 67 tephra layers deposited over the last 8750 cal yr, comprising 15% of the total thickness of recovered sediment. Using 12 AMS {sup 14}C ages, along with the {sup 137}Cs and {sup 210}Pb activities of recent sediment, we evaluated different models to determine the age-depth relation of sediment, and to determine the age of each tephra deposit. The age model is based on a cubic smooth spline function that was passed through the adjusted tephra-free depth of each dated layer. The estimated age uncertainty of the 67 tephras averages {+-} 105 yr (1{sigma}). Tephra-fall frequency at Bear Lake was among the highest during the past 500 yr, with eight tephras deposited compared to an average of 3.7 per 500 yr over the last 8500 yr. Other periods of increased tephra fall occurred 2500-3500, 4500-5000, and 7000-7500 cal yr. Our record suggests that Bear Lake experienced extended periods (1000-2000 yr) of increased tephra fall separated by shorter periods (500-1000 yr) of apparent quiescence. The Bear Lake sediment core affords the most comprehensive tephrochronology from the base of the Redoubt Volcano to date, with an average tephra-fall frequency of once every 130 yr.

  18. 210Pb and 137Cs dating of sediments from Zigetang Lake, Tibetan Plateau

    International Nuclear Information System (INIS)

    Yao, S.C.; Li, S.J.; Zhang, H.C.

    2008-01-01

    Zigetang Lake located in the central Tibetan Plateau was selected for the purpose of understanding of recent sedimentation rates. Based on 137 Cs dating marker, the sediment rate was 0.077 cm x yr -1 . The sedimentation rate was calculated to be 0.071 cm x yr -1 and 0.029 g x cm -2 x yr -1 on the basis of 210 Pb CIC model. 210 Pb CRS model was also used for understanding of recent sedimentation change. The sediment accumulation rates for the CRS model ranged from 0.022 to 0.038 g x cm -2 x yr -1 with an irregular high value of 0.12 g x cm -2 x yr -1 around 1932 at Zigetang Lake core in the past eighty years. (author)

  19. Methane Bubbles Transport Particles From Contaminated Sediment to a Lake Surface

    Science.gov (United States)

    Delwiche, K.; Hemond, H.

    2017-12-01

    Methane bubbling from aquatic sediments has long been known to transport carbon to the atmosphere, but new evidence presented here suggests that methane bubbles also transport particulate matter to a lake surface. This transport pathway is of particular importance in lakes with contaminated sediments, as bubble transport could increase human exposure to toxic metals. The Upper Mystic Lake in Arlington, MA has a documented history of methane bubbling and sediment contamination by arsenic and other heavy metals, and we have conducted laboratory and field studies demonstrating that methane bubbles are capable of transporting sediment particles over depths as great as 15 m in Upper Mystic Lake. Methane bubble traps were used in-situ to capture particles adhered to bubble interfaces, and to relate particle mass transport to bubble flux. Laboratory studies were conducted in a custom-made 15 m tall water column to quantify the relationship between water column height and the mass of particulate transport. We then couple this particle transport data with historical estimates of ebullition from Upper Mystic Lake to quantify the significance of bubble-mediated particle transport to heavy metal cycling within the lake. Results suggest that methane bubbles can represent a significant pathway for contaminated sediment to reach surface waters even in relatively deep water bodies. Given the frequent co-occurrence of contaminated sediments and high bubble flux rates, and the potential for human exposure to heavy metals, it will be critical to study the significance of this transport pathway for a range of sediment and contaminant types.

  20. Geographic relatedness and predictability of Escherichia coli along a peninsular beach complex of Lake Michigan

    Science.gov (United States)

    Nevers, M.B.; Shively, D.A.; Kleinheinz, G.T.; McDermott, C.M.; Schuster, W.; Chomeau, V.; Whitman, R.L.

    2009-01-01

    To determine more accurately the real-time concentration of fecal indicator bacteria (FIB) in beach water, predictive modeling has been applied in several locations around the Great Lakes to individual or small groups of similar beaches. Using 24 beaches in Door County, Wisconsin, we attempted to expand predictive models to multiple beaches of complex geography. We examined the importance of geographic location and independent variables and the consequential limitations for potential beach or beach group models. An analysis of Escherichia coli populations over 4 yr revealed a geographic gradient to the beaches, with mean E. coli concentrations decreasing with increasing distance from the city of Sturgeon Bay. Beaches grouped strongly by water type (lake, bay, Sturgeon Bay) and proximity to one another, followed by presence of a storm or creek outfall or amount of shoreline enclosure. Predictive models developed for beach groups commonly included wave height and cumulative 48-h rainfall but generally explained little E. coli variation (adj. R2 = 0.19-0.36). Generally low concentrations of E. coli at the beaches influenced the effectiveness of model results presumably because of low signal-to-noise ratios and the rarity of elevated concentrations. Our results highlight the importance of the sensitivity of regressors and the need for careful methods evaluation. Despite the attractiveness of predictive models as an alternative beach monitoring approach, it is likely that FIB fluctuations at some beaches defy simple prediction approaches. Regional, multi-beach, and individual beach predictive models should be explored alongside other techniques for improving monitoring reliability at Great Lakes beaches. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  1. Preliminary study of the chronology of the sedimentation process in lakes

    International Nuclear Information System (INIS)

    Patrocinio Junior, Antonio C.; Andrello, Avacir C.

    2009-01-01

    The soil erosion accelerated which produces the presence of sediment in rivers is one of the main environmental problems and represents a challenge for the sustainable use of soil and water resources. The problems associated with the increased sediments production are mainly related to the rivers siltation, reduced storage capacity of dams and reservoirs and reduction in the quality of aquatic environment. Thus, further information on sedimentation rates in lakes and reservoirs are required, as a parameter for estimating the chronology of production rates of sediment. Therefore, methods to establish the chronology of recent sediments are central base for such research. The cesium-137 is an artificial radionuclide with a half life of 30.2 years, inserted in the environment through the 'fallout' radioactive between the 1950's and 1970's, with two predominant peaks of deposition in 1959 and 1964. The basis for using the cesium-137 in this context (chronology of sediments) is that the cesium-137 is rapidly and strongly adsorbed to fine particles of soil and its distribution in the sediment profile directly reflects the chronology of sediment deposition. The purpose of this work is to use the cesium-137 profile in lake sediments to assess the history of deposition and to obtain information about the erosive process. For this, lake sediments of a mini-hydroelectric power plant built in the 1940's in the city of Londrina-PR were analyzed, showing that cesium-137 can be used as a source of data for chronological assessment of erosive processes occurring in the vicinity of the lake. (author)

  2. [Composition and Environmental Effects of LFOM and HFOM in "Incense-Ash" Sediments of West Lake, Hangzhou, China].

    Science.gov (United States)

    Li, Jing; Zhu, Guang-wei; Zhu, Meng-yuan; Gong, Zhi-jun; Xu, Hai; Yang, Gui-jun

    2015-06-01

    To understand the organic matter pollution characteristic and its relationship with nitrogen, phosphorus and other nutrients in sediments of high organic matter type of urban shallow lakes, the organic matter content, light fraction organic matter (LFOM), heavy fraction organic matter (HFOM), and nitrogen and phosphorus contents were investigated in eight different regions of West Lake, Hangzhou. The results showed that, the organic matter content of the west lake sediment was 28-251 g x kg(-1), belonging to typical high organic matter sediment. The difference of organic matter content in different lake sediments was very big. The sediments located at the input site of water diversion engineering had significantly lower organic content than the rest regions. The LFOM content of West Lake sediment ranged 0.57-9.17 g x kg(-1), which averagely occupied 2.83% of the total organic matter, and the HFOM content ranged 5.35-347.41 g x kg(-1), which occupied more than 90% of the total organic matter. Compared to other shallow lakes located in China, sediments of West Lake had significantly high percentage of HFOM/LFOM ratio. But the HFOM content was obviously on the high side, reflecting the west lake as an urban lake with a long history, as well as high organic matter pollution load and sediment humification degree. Both the content and the ratio of LFOM/HFOM in sediment were related to nitrogen and phosphorus contents in sediment. This suggested that the composition of organic matter in West Lake sediments had potential control ability for the internal loading of N and P of the lake.

  3. Spatiotemporal patterns of mercury accumulation in lake sediments of western North America

    Science.gov (United States)

    Drevnick, Paul; Cooke, Colin A.; Barraza, Daniella; Blais, Jules M.; Coale, Kenneth; Cumming, Brian F.; Curtis, Chris; Das, Biplob; Donahue, William F.; Eagles-Smith, Collin A.; Engstrom, Daniel R.; Fitzgerald, William F.; Furl, Chad V.; Gray, John R.; Hall, Roland I.; Jackson, Togwell A.; Laird, Kathleen R.; Lockhart, W. Lyle; Macdonald, Robie W.; Mast, M. Alisa; Mathieu, Callie; Muir, Derek C.G.; Outridge, Peter; Reinemann, Scott; Rothenberg, Sarah E.; Ruiz-Fernandex, Ana Carolina; St. Louis, V.L.; Sanders, Rhea; Sanei, Hamed; Skierszkan, Elliott; Van Metre, Peter C.; Veverica, Timothy; Wiklund, Johan A.; Wolfe, Brent B.

    2016-01-01

    For the Western North America Mercury Synthesis, we compiled mercury records from 165 dated sediment cores from 138 natural lakes across western North America. Lake sediments are accepted as faithful recorders of historical mercury accumulation rates, and regional and sub-regional temporal and spatial trends were analyzed with descriptive and inferential statistics. Mercury accumulation rates in sediments have increased, on average, four times (4×) from 1850 to 2000 and continue to increase by approximately 0.2 μg/m2 per year. Lakes with the greatest increases were influenced by the Flin Flon smelter, followed by lakes directly affected by mining and wastewater discharges. Of lakes not directly affected by point sources, there is a clear separation in mercury accumulation rates between lakes with no/little watershed development and lakes with extensive watershed development for agricultural and/or residential purposes. Lakes in the latter group exhibited a sharp increase in mercury accumulation rates with human settlement, stabilizing after 1950 at five times (5×) 1850 rates. Mercury accumulation rates in lakes with no/little watershed development were controlled primarily by relative watershed size prior to 1850, and since have exhibited modest increases (in absolute terms and compared to that described above) associated with (regional and global) industrialization. A sub-regional analysis highlighted that in the ecoregion Northwestern Forest Mountains, mercury deposited to watersheds is delivered to lakes. Research is warranted to understand whether mountainous watersheds act as permanent sinks for mercury or if export of “legacy” mercury (deposited in years past) will delay recovery when/if emissions reductions are achieved.

  4. Lead pollution in a large, prairie-pothole lake (Rush Lake, WI, USA): Effects on abundance and community structure of indigenous sediment bacteria

    International Nuclear Information System (INIS)

    Grandlic, Christopher J.; Geib, Ian; Pilon, Renee; Sandrin, Todd R.

    2006-01-01

    Rush Lake (WI, USA), the largest prairie-pothole lake east of the Mississippi River, has been contaminated with lead pollution as a result of over 140 years of waterfowl hunting. We examined: (1) the extent of lead pollution in Rush Lake sediments and (2) whether lead pollution in Rush Lake is affecting the abundance and community structure of indigenous sediment bacteria. Sediment lead concentrations did not exceed 59 mg Pb kg -1 dry sediment. No relationship was observed between sediment lead concentration and the abundance of aerobic (P = 0.498) or anaerobic (P = 0.416) heterotrophic bacteria. Similarly, lead did not appear to affect bacterial community structure when considering both culturable and nonculturable community members. In contrast, the culturable fraction of sediment bacteria in samples containing 59 mg Pb kg -1 exhibited a unique community structure. While factors other than lead content likely play roles in determining bacterial community structure in the sediments of Rush Lake, these data suggest that the culturable fraction of sediment bacterial communities is affected by elevated lead levels. - Low levels of lead pollution in Rush Lake are not impinging upon the abundance of indigenous sediment bacteria, but may be affecting the community structure of the culturable fraction of these bacteria

  5. Preliminary Nearshore Sedimentation Rate Analysis of the Tuungane Project Northern Mahale Conservation Area, Lake Tanganyika (Tanzania)

    Science.gov (United States)

    Smiley, R. A.; McGlue, M. M.; Yeager, K. M.; Soreghan, M. J.; Lucas, J.; Kimirei, I.; Mbonde, A.; Limbu, P.; Apse, C.

    2017-12-01

    The combined effects of climate change, overfishing, and sediment pollution are altering Lake Tanganyika's littoral fisheries in profoundly negative ways. One method for conserving critical fish resources and safeguarding biodiversity in Lake Tanganyika is by establishing small-scale nearshore protected zones, which can be administrated by lakeshore villagers organized into beach management units (BMUs). Each BMU endeavors to manage offshore "no-catch" protected zones, prohibit the use of illegal fishing gear, and promote sustainable agriculture that abates erosion in the lake watershed, in order to mitigate sediment pollution in the lake. We adopted a limnogeological approach to assist in characterizing the littoral zone associated with BMUs in the northern Mahale region of Lake Tanganyika (Tanzania), a critical conservation area for the Nature Conservancy's Tuungane Project (https://www.nature.org/ourinitiatives/regions/africa/wherewework/tuungane-project.xml). We hypothesized that BMUs with heavy onshore agricultural activity would experience relatively high offshore sedimentation rates, due to enhanced sediment-laden runoff in the wet season. Such changes are predicted to alter benthic substrates and degrade habitat available for fish spawning. We mapped bathymetry and sediment types along a 29 km2 area of the littoral zone using high-resolution geophysical tools, and assessed short-term sedimentation rates using sediment cores and radionuclide geochronology (210Pb). Initial results from 210Pb analyses show that sedimentation rates at the mud-line ( 85-100 m water depth) are relatively slow but spatially variable in the northern Mahale area. Offshore of the Kalilani village BMU, linear sedimentation rates are 0.50 mm/yr. By contrast, sedimentation rates offshore from the Igualula village BMU are 0.90-1.30 mm/yr. Higher sedimentation rates near Igualula are consistent with greater sediment inputs from the nearby Lagosa River and its watershed, which has been

  6. Sediment-water gas exchange in two Swedish lakes measured by Eddy Correlation

    Science.gov (United States)

    Kokic, J.; Sahlee, E.; Brand, A.; Sobek, S.

    2014-12-01

    Lake sediments are hotspots for carbon (C) cycling, acting both as sinks and sources through C burial and production of carbon dioxide (CO2) and methane. The fate of this CO2 in the water column is controlled by bottom water turbulence, a factor not accounted for in current estimates of sediment CO2 fluxes. This study is aimed to quantify the turbulent CO2 flux across the sediment-water interface (SWI) by measuring the oxygen (O2) flux with the non-invasive Eddy Correlation (EC) method that combines measurements of 3D velocity (ADV) and O2 fluctuations with a microsensor. Using the metabolic relation (respiratory quotient, RQ) of O2 and CO2 derived from a sediment incubation experiment we present the first estimates of turbulent lake sediment CO2 flux from two boreal lakes in Sweden (Erssjön and Erken, 0.07 km2 and 23.7 km2 respectively). Only ~10 % of the total dataset was extracted for flux calculations due to poor signal-to-noise ratio in the velocity and O2 signals. The sediment in Lake Erssjön was both consuming and producing O2, related to bacterial respiration and photosynthesis. Mean O2 flux was -0.19 and 0.17 μmol O2 m-2 sec-1, comparing to 0.04 μmol O2 m-2 sec-1 derived from the sediment incubation experiment. Fluxes for Lake Erken are still to be determined. Experimentally derived RQ of the both lake sediments were close to unity implying that in-situ CO2 fluxes are of similar magnitude as O2 fluxes, varying between -0.15 and 0.18 μmol C m-2 sec-1. The first measurement of turbulent sediment O2 flux and estimate of turbulent CO2 flux from a small boreal lake show higher and more variable fluxes than previously found in experimental studies. The low amount of data extracted for flux calculations (~10%) point towards the difficulties in EC measurement in low-turbulence environments. On-going work focuses on the turbulence structure in lakes and its influence on the gas fluxes at the SWI.

  7. Sediment sources and storages in the urbanizing South Creek catchment, Lake Macquarie, NSW

    International Nuclear Information System (INIS)

    Curtis, S.J.

    1988-10-01

    An investigation of the sediment source areas and sediment storages has been undertaken in the South Creek catchment, Lake Macquarie, NSW. Source areas have been examined by analyzing suspended sediment concentrations, field measurements and observations, and caesium-137 values. The caesium-137 technique and field measurements were used to study the sediment storages on the South Creek flood plain. Particle size analysis of sediments on the slopes and flood plain were undertaken to provide information on the efficiency of the sediment transport system. The results of these investigations indicate that the developing urban areas are the main sources of poorest water quality (in terms of suspended sediment) in the South Creek catchment. The open woodland, rural and established urban areas were minor sediment source areas, although the open woodland had the potential to become a major sediment source if disturbed by human activities. The developing urban areas had efficient sediment transport systems, while the open woodland and rural areas tended to deposit sediment locally. The upstream section of the flood plain was found to be storing more sediment than the downstream section. The study revealed that when urban development occurs on the steeper gradients of the South Creek catchment erosion processes are greatly accelerated and thus the developing urban area becomes the major source of poorest water quality in the catchment. The importance of the developing urban area as a sediment source needs to be considered in any future land developments in urbanizing drainage basins

  8. Contribution to the study of sedimentation rates in some french Polynesian lakes and lagoon

    International Nuclear Information System (INIS)

    Serra, C.; Poletiko, C.; Badie, C.

    1991-03-01

    210 Pb measurements using 210 Po deposition technique were performed in several marine and lacustrine sediments of French Polynesia to determine sedimentation rates in lakes and lagoons. Some results in terrigeneous sediments were acceptable and permit rate measurements; on the contrary other sediments, especially coral sands provided a 210 Pb/ 226 Ra disequilibrium (0.33 to 0.69). The occurring phenomena seem to be related to 222 Rn scavenging and geothermal endoupwelling which induces 226 Ra enhancement; this leads to the same 210 Pb/ 226 Ra disequilibrium as in deep ocean waters as described, for instance by Thomson and Turekian (1976) in an upwelling zone on Peru coasts [fr

  9. [Characteristics of organic carbon forms in the sediment of Wuliangsuhai and Daihai Lakes].

    Science.gov (United States)

    Mao, Hai-Fang; He, Jiang; Lü, Chang-Wei; Liang, Ying; Liu, Hua-Lin; Wang, Feng-Jiao

    2011-03-01

    The characteristics and differences of organic carbon forms in the sediments of the Wuliangsuhai and the Daihai Lakes with different eutrophication types were discussed in the present study. The results showed that the range of total organic carbon content (TOC) in Wuliangsuhai Lake was 4.50-22.83 g x kg(-1) with the average of 11.80 g x kg(-1). The range of heavy-fraction organic carbon content was 3.38-21.67 g x kg(-1) with the average of 10.76 g x kg(-1). The range of light-fraction organic carbon content was 0.46-1.80 g x kg(-1) with the average of 1.04 g x kg(-1); The range of ROC content was 0.62-3.64 g x kg(-1) with the average of 2.11 g x kg(-1), while the range of total organic carbon content in Daihai lake was 6.84-23.46 g x kg(-1) with the average of 14.94 g x kg(-1). The range of heavy-fraction organic carbon content was 5.27-22.23 g x kg(-1) with the average of 13.89 g x kg(-1). The range of light-fraction organic carbon content was 0.76-1.57 g x kg(-1). The range of ROC content was 1.54-7.08 g x kg(-1) with the average of 3.62 g x kg(-1). The results indicated that the heavy-fraction organic carbon was the major component of the organic carbon and plays an important role in the accumulation of organic carbon in the sediments of two Lakes. The content of light-fraction organic carbon was similar in the sediments of two lakes, whereas, the contents of total organic carbon and heavy-fraction organic carbon in the sediment of Wuliangsuhai Lake were less than those in the sediment of Daihai Lake, and the value of LFOC/TOC in the Wuliangsuhai Lake was larger than that in the Daihai Lake. The humin was the dominant component of the sediment humus, followed by fulvic acid in the two lakes. The values of HM/HS in the sediments of Wuliangsuhai lake range from 43.06% to 77.25% with the average of 62.15% and values of HM/HS in the sediments of Dahai lake range from 49.23% to 73.85% with the average of 65.30%. The tightly combined humus was the dominant form in

  10. Mercury pollution in the lake sediments and catchment soils of anthropogenically-disturbed sites across England.

    Science.gov (United States)

    Yang, Handong; Turner, Simon; Rose, Neil L

    2016-12-01

    Sediment cores and soil samples were taken from nine lakes and their catchments across England with varying degrees of direct human disturbance. Mercury (Hg) analysis demonstrated a range of impacts, many from local sources, resulting from differing historical and contemporary site usage and management. Lakes located in industrially important areas showed clear evidence for early Hg pollution with concentrations in sediments reaching 400-1600 ng g -1 prior to the mid-19th century. Control of inputs resulting from local management practices and a greater than 90% reduction in UK Hg emissions since 1970 were reflected by reduced Hg pollution in some lakes. However, having been a sink for Hg deposition for centuries, polluted catchment soils are now the major Hg source for most lakes and consequently recovery from reduced Hg deposition is being delayed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. The effect of dissolved organic carbon on pelagial and near-sediment water traits in lakes

    Directory of Open Access Journals (Sweden)

    Krzysztof Banaś

    2011-01-01

    Full Text Available The effect of dissolved organic carbon (DOC on the environmental conditions of macrophytes has been studied in 35 lakes divided into soft- and hardwater: oligohumic (16.0 mg C dm-3. The optimum environmental conditions for macrophytes have been found in oligohumic lakes, characterised by low water colour and its good transparency. In soft- and hardwater lakes increasing concentration of DOC is accompanied with an increase in the colour (r=0.95, while the visibility decreases. With increasing DOC in the near-sediment layer the pH values decrease while the concentration of nitrogen increases and the concentration of phosphorus slightly increases. In hardwater lakes with increasing DOC concentration, the redox potential, conductivity, total hardness and calcium concentration in the near-sediment water decrease, whereas the content of CO2 remains at a very low level.

  12. Distribution of global fallout 237Np, Pu isotopes, and 241Am in lake and sea sediments

    International Nuclear Information System (INIS)

    Yamamoto, Masayoshi; Yamauchi, Y.; Chatani, K.; Komura, K.; Ueno, Kaoru; Sakanoue, Masanobu

    1991-01-01

    In order to investigate the sedimentary behaviour of neptunium, 237 Np together with Pu isotopes and 241 Am were measured for the sediment cores collected from Lake Mikata (freshwater), from Lake Kugushi (brakish water) and from Nyu Bay (sea water). In all sediment core samples 237 Np was detected, and its concentrations were far below those of 239,240 Pu and 241 Am measured for the same samples. Inventories of 237 Np in the lakes were estimated to be 0.53, 0.29 and 0.34 MBq/km 2 , respectively. The activity ratios of 237 Np/ 239,240 Pu, except for Lake Mikata, are two or three times lower than the value of 0.3-0.4% observed for surface soils of 0-20 cm depth, suggesting that Np is more soluble compared with Pu. (author) 21 refs.; 6 figs.; 3 tabs

  13. Questa baseline and premining ground-water quality investigation. 8. Lake-sediment geochemical record from 1960 to 2002, Eagle Rock and Fawn Lakes, Taos County, New Mexico

    Science.gov (United States)

    Church, S.E.; Fey, D.L.; Marot, M.E.

    2005-01-01

    Geochemical studies of lake sediment from Eagle Rock Lake and upper Fawn Lake were conducted to evaluate the effect of mining at the Molycorp Questa porphyry molybdenum deposit located immediately north of the Red River. Two cores were taken, one from each lake near the outlet where the sediment was thinnest, and they were sampled at 1-cm intervals to provide geochemical data at less than 1-year resolution. Samples from the core intervals were digested and analyzed for 34 elements using ICP-AES (inductively coupled plasma-atomic emission spectrometry). The activity of 137Cs has been used to establish the beginning of sedimentation in the two lakes. Correlation of the geochemistry of heavy-mineral suites in the cores from both Fawn and Eagle Rock Lakes has been used to develop a sedimentation model to date the intervals sampled. The core from upper Fawn Lake, located upstream of the deposit, provided an annual sedimentary record of the geochemical baseline for material being transported in the Red River, whereas the core from Eagle Rock Lake, located downstream of the deposit, provided an annual record of the effect of mining at the Questa mine on the sediment in the Red River. Abrupt changes in the concentrations of many lithophile and deposit-related metals occur in the middle of the Eagle Rock Lake core, which we correlate with the major flood-of-record recorded at the Questa gage at Eagle Rock Lake in 1979. Sediment from the Red River collected at low flow in 2002 is a poor match for the geochemical data from the sediment core in Eagle Rock Lake. The change in sediment geochemistry in Eagle Rock Lake in the post-1979 interval is dramatic and requires that a new source of sediment be identified that has substantially different geochemistry from that in the pre-1979 core interval. Loss of mill tailings from pipeline breaks are most likely responsible for some of the spikes in trace-element concentrations in the Eagle Rock Lake core. Enrichment of Al2O3, Cu, and Zn

  14. Emerging technologies and approaches to minimize discharges into Lake Michigan, phase 2 module 4 report.

    Energy Technology Data Exchange (ETDEWEB)

    Negri, M.C.; Gillenwater, P.; Urgun-Demirtas, M.; Nnanna, G.; Yu, J.; Jannotta, I, (Energy Systems); (Purdue University Calumet)

    2012-04-19

    The Great Lakes Initiative (GLI) established the new water quality-based discharge criteria for mercury (Hg), thereby increasing the need for many municipal and industrial wastewater treatment plants in the region to lower the mercury in their effluents. Information on deployable technologies to satisfy these requirements for industrial and municipal dischargers in the Great lakes region is scarce. Therefore, BP funded Purdue University Calumet and Argonne to identify deployable Hg removal technologies to meet the GLI discharge criterion at its Whiting Refinery in Indiana. The joint PUC/Argonne project was divided into 2 phases. Results from Phase I and Phase II Modules 1-3 have been previously reported. This report summarizes the work done in Phase 3 Module 4, which consisted of the pilot scale testing of Hg removal technologies previously selected in Module 3. The pilot testing was an Argonne/PUC jointly directed project that was hosted at and funded by the BP refinery in Whiting, IN. As two organizations were involved in data analysis and interpretation, this report combines two independent sets of evaluations of the testing that was done, prepared respectively by Argonne and Purdue. Each organization retains sole responsibility for its respective analysis conclusions and recommendations. Based on Module 3 bench testing with pre-Effluent To Lake (pre-ETL) and clarifier effluent (CE) samples from the Whiting refinery, three different technologies were chosen for pilot testing: (1) Ultrafiltration (using GE ZeeWeed(reg sign) Technology, 0.04 {mu}m pore size and made up of PVDF) for particulate mercury removal; (2) Adsorption using Mersorb(reg sign) LW, a sulfur-impregnated activated carbon, for dissolved mercury removal if present and (3) The Blue PRO(reg sign) reactive filtration process for both particulate and dissolved (if present) mercury removal. The ultrafiltration and the Blue PRO(reg sign) reactive filtration pilot studies were done simultaneously at the

  15. Characterization of expandable clay minerals in Lake Baikal sediments by thermal dehydration and cation exchange

    Czech Academy of Sciences Publication Activity Database

    Grygar, Tomáš; Bezdička, Petr; Hradil, David; Hrušková, Michaela; Novotná, Kateřina; Kadlec, Jaroslav; Pruner, Petr; Oberhansli, H.

    2005-01-01

    Roč. 53, č. 4 (2005), s. 389-400 ISSN 0009-8604 R&D Projects: GA AV ČR(CZ) IAA3032401 Grant - others:European Commission(XE) EVK2-2000-00057 Institutional research plan: CEZ:AV0Z40320502 Keywords : cation exchange capacity * Lake Baikal * Lake Sediments Subject RIV: CA - Inorganic Chemistry Impact factor: 1.364, year: 2005

  16. Archaeal community changes in Lateglacial lake sediments: Evidence from ancient DNA

    Science.gov (United States)

    Ahmed, Engy; Parducci, Laura; Unneberg, Per; Ågren, Rasmus; Schenk, Frederik; Rattray, Jayne E.; Han, Lu; Muschitiello, Francesco; Pedersen, Mikkel W.; Smittenberg, Rienk H.; Yamoah, Kweku Afrifa; Slotte, Tanja; Wohlfarth, Barbara

    2018-02-01

    The Lateglacial/early Holocene sediments from the ancient lake at Hässeldala Port, southern Sweden provide an important archive for the environmental and climatic shifts at the end of the last ice age and the transition into the present Interglacial. The existing multi-proxy data set highlights the complex interplay of physical and ecological changes in response to climatic shifts and lake status changes. Yet, it remains unclear how microorganisms, such as Archaea, which do not leave microscopic features in the sedimentary record, were affected by these climatic shifts. Here we present the metagenomic data set of Hässeldala Port with a special focus on the abundance and biodiversity of Archaea. This allows reconstructing for the first time the temporal succession of major Archaea groups between 13.9 and 10.8 ka BP by using ancient environmental DNA metagenomics and fossil archaeal cell membrane lipids. We then evaluate to which extent these findings reflect physical changes of the lake system, due to changes in lake-water summer temperature and seasonal lake-ice cover. We show that variations in archaeal composition and diversity were related to a variety of factors (e.g., changes in lake water temperature, duration of lake ice cover, rapid sediment infilling), which influenced bottom water conditions and the sediment-water interface. Methanogenic Archaea dominated during the Allerød and Younger Dryas pollen zones, when the ancient lake was likely stratified and anoxic for large parts of the year. The increase in archaeal diversity at the Younger Dryas/Holocene transition is explained by sediment infilling and formation of a mire/peatbog.

  17. Metal impacts on microbial biomass in the anoxic sediments of a contaminated lake

    Energy Technology Data Exchange (ETDEWEB)

    Gough, Heidi L.; Dahl, Amy L.; Nolan, Melissa A.; Gaillard, Jean-Francois; Stahl, David A.

    2008-04-26

    Little is known about the long-term impacts of metal contamination on the microbiota of anoxic lake sediments. In this study, we examined microbial biomass and metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, and zinc) in the sediments of Lake DePue, a backwater lake located near a former zinc smelter. Sediment core samples were examined using two independent measures for microbial biomass (total microscopic counts and total phospholipid-phosphate concentrations), and for various fractions of each metal (pore water extracts, sequential extractions, and total extracts of all studied metals and zinc speciation by X-ray absorption fine structure (XAFS). Zinc concentrations were up to 1000 times higher than reported for sediments in the adjacent Illinois River, and ranged from 21,400 mg/kg near the source to 1,680 mg/kg near the river. However, solid metal fractions were not well correlated with pore water concentrations, and were not good predictors of biomass concentrations. Instead, biomass, which varied among sites by as much as two-times, was inversely correlated with concentrations of pore water zinc and arsenic as established by multiple linear regression. Monitoring of other parameters known to naturally influence biomass in sediments (e.g., organic carbon concentrations, nitrogen concentrations, pH, sediment texture, and macrophytes) revealed no differences that could explain observed biomass trends. This study provides strong support for control of microbial abundance by pore water metal concentrations in contaminated freshwater sediments.

  18. Status of heavy metal in sediment of Saguling Lake, West Java

    Science.gov (United States)

    Wardhani, E.; Roosmini, D.; Notodarmojo, S.

    2017-03-01

    The quality of water in the Saguling lake has been monitored since 1990 by the state agency for environmental control. However, no data on heavy metal in sediment had been reported. Metal pollutans have receives considerable attention due to their persistence, biogeochemical recycling, and environmental risk. The objective of this study was to assess the level contamination of heavy metals (Cd, Cr, Cu, and Pb) in the surface sediment of the Saguling Lake West Java. Surface sediment samples were collected from 10 location of the Saguling Lake on July and November 2015. The concentration of heavy metals in the surface sediment on July and November 2015 decreased in the order of Cu>Cr>Pb>Cd and Cr>Cu>Pb>Cd respectively. Mean metals concentrations (mg/kg) in July 2015 were in the range of: Cd: 10.69-16.65, Cr: 76.67-138.38, Cu:106.02-229.54, Pb: 23.93-80.17. Mean metals concentrations (mg/kg) in November 2015 were in the range of Cd: 18.64-23.25, Cr: 152.16-197.98, Cu: 63.32-152.53, Pb: 20.31-32.74. Geochemical approaches such as contamination factor, and pollution load index were exploited for the assessment of the contamination and enrichment level of heavy metals in the lake sediment. Contamination factor and pollution load index values indicated that surface sediments around Saguling Lake were polluted with heavy metals. The finding of this study would help in formulating guidelines to control the pollution and suggested for Saguling lake revitalization.

  19. 14C dating of freshwater carbonate sediments with special reference to calcareous tufas and laminated lake sediments

    International Nuclear Information System (INIS)

    Pazdur, M.F.

    1992-09-01

    The sequence of laminated sediment of the lake Gosciaz, Poland, covers more than 13,000 years and is actually the longest sequence known so far. Besides of reconstructing past environmental changes, this sequence offers an excellent possibility for studying natural C-14 variations and calibrating the C-14 time scale in a range beyond 6,000 years B.P. The floating varve chronology based on previously taken sediment cores which cover a period of 9,682 years, has been improved by this study. Relative water level changes of the lake during the past 11,500 years have been reconstructed by means of C-14 and C-13 measurements carried out on carbonate fractions of the lake sediments. Periodical variations in the width of annual layers were found. The periods identified are 11 years and 22 years (solar cycle), 35 years (Bruckner cycle), and 200 years. The ratio of summer layer width and the total width of the annual layer shows secular changes which correlate with paleotemperature records. The duration of the Younger Dryas period was determined by combining the floating varve chronology with isotope and pollen analyses of the sediment material. A value of 1,500 years was found. The study also included radiocarbon dating of calcareous tufa taken from different study areas. 26 refs, 26 figs, 6 tabs

  20. Diversity of active aerobic methanotrophs along depth profiles of arctic and subarctic lake water column and sediments

    Science.gov (United States)

    He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Quensen, John; Tiedje, James M.; Leigh, Mary Beth

    2012-01-01

    Methane (CH4) emitted from high-latitude lakes accounts for 2–6% of the global atmospheric CH4 budget. Methanotrophs in lake sediments and water columns mitigate the amount of CH4 that enters the atmosphere, yet their identity and activity in arctic and subarctic lakes are poorly understood. We used stable isotope probing (SIP), quantitative PCR (Q-PCR), pyrosequencing and enrichment cultures to determine the identity and diversity of active aerobic methanotrophs in the water columns and sediments (0–25 cm) from an arctic tundra lake (Lake Qalluuraq) on the north slope of Alaska and a subarctic taiga lake (Lake Killarney) in Alaska's interior. The water column CH4 oxidation potential for these shallow (~2m deep) lakes was greatest in hypoxic bottom water from the subarctic lake. The type II methanotroph, Methylocystis, was prevalent in enrichment cultures of planktonic methanotrophs from the water columns. In the sediments, type I methanotrophs (Methylobacter, Methylosoma and Methylomonas) at the sediment-water interface (0–1 cm) were most active in assimilating CH4, whereas the type I methanotroph Methylobacter and/or type II methanotroph Methylocystis contributed substantially to carbon acquisition in the deeper (15–20 cm) sediments. In addition to methanotrophs, an unexpectedly high abundance of methylotrophs also actively utilized CH4-derived carbon. This study provides new insight into the identity and activity of methanotrophs in the sediments and water from high-latitude lakes.

  1. Environmental evidence of fossil fuel pollution in Laguna Chica de San Pedro lake sediments (Central Chile)

    Energy Technology Data Exchange (ETDEWEB)

    Chirinos, L. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile)]. E-mail: lchirin@pucp.edu.pe; Rose, N.L. [Environmental Change Research Centre, University College London, 26 Bedford Way, London WG1HOAP (United Kingdom); Urrutia, R. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Munoz, P. [Departamento de Biologia Marina, Universidad Catolica del Norte, Larrondo 1281, Coquimbo (Chile); Torrejon, F. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Torres, L. [Departamento de Botanica, Universidad de Concepcion, Concepcion (Chile); Cruces, F. [Departamento de Botanica, Universidad de Concepcion, Concepcion (Chile); Araneda, A. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Zaror, C. [Facultad de Ingenieria Quimica, Universidad de Concepcion, Concepcion (Chile)

    2006-05-15

    This paper describes lake sediment spheroidal carbonaceous particle (SCP) profiles from Laguna Chica San Pedro, located in the Biobio Region, Chile (36{sup o} 51' S, 73{sup o} 05' W). The earliest presence of SCPs was found at 16 cm depth, corresponding to the 1915-1937 period, at the very onset of industrial activities in the study area. No SCPs were found at lower depths. SCP concentrations in Laguna Chica San Pedro lake sediments were directly related to local industrial activities. Moreover, no SCPs were found in Galletue lake (38{sup o} 41' S, 71{sup o} 17.5' W), a pristine high mountain water body used here as a reference site, suggesting that contribution from long distance atmospheric transport could be neglected, unlike published data from remote Northern Hemisphere lakes. These results are the first SCP sediment profiles from Chile, showing a direct relationship with fossil fuel consumption in the region. Cores were dated using the {sup 21}Pb technique. - The lake sediment record of SCPs shows the record of fossil-fuel derived pollution in Central Chile.

  2. Environmental evidence of fossil fuel pollution in Laguna Chica de San Pedro lake sediments (Central Chile)

    International Nuclear Information System (INIS)

    Chirinos, L.; Rose, N.L.; Urrutia, R.; Munoz, P.; Torrejon, F.; Torres, L.; Cruces, F.; Araneda, A.; Zaror, C.

    2006-01-01

    This paper describes lake sediment spheroidal carbonaceous particle (SCP) profiles from Laguna Chica San Pedro, located in the Biobio Region, Chile (36 o 51' S, 73 o 05' W). The earliest presence of SCPs was found at 16 cm depth, corresponding to the 1915-1937 period, at the very onset of industrial activities in the study area. No SCPs were found at lower depths. SCP concentrations in Laguna Chica San Pedro lake sediments were directly related to local industrial activities. Moreover, no SCPs were found in Galletue lake (38 o 41' S, 71 o 17.5' W), a pristine high mountain water body used here as a reference site, suggesting that contribution from long distance atmospheric transport could be neglected, unlike published data from remote Northern Hemisphere lakes. These results are the first SCP sediment profiles from Chile, showing a direct relationship with fossil fuel consumption in the region. Cores were dated using the 21 Pb technique. - The lake sediment record of SCPs shows the record of fossil-fuel derived pollution in Central Chile

  3. Aeolian particle transport inferred using a ~150-year sediment record from Sayram Lake, arid northwest China

    Directory of Open Access Journals (Sweden)

    Long Ma

    2015-05-01

    Full Text Available We studied sediment cores from Sayram Lake in the Tianshan Mountains of northwest China to evaluate variations in aeolian transport processes over the past ~150 years. Using an end-member modeling algorithm of particle size data, we interpreted end members with a strong bimodal distribution as having been transported by aeolian processes, whereas other end members were interpreted to have been transported by fluvial processes. The aeolian fraction accounted for an average of 27% of the terrigenous components in the core. We used the ratio of aeolian to fluvial content in the Sayram Lake sediments as an index of past intensity of aeolian transport in the Tianshan Mountains. During the interval 1910-1930, the index was high, reflecting the fact that dry climate provided optimal conditions for aeolian dust transport. From 1930-1980, the intensity of aeolian transport was weak. From the 1980s to the 2000s, aeolian transport to Sayram Lake increased. Although climate in northwest China became more humid in the mid-1980s, human activity had by that time altered the impact of climate on the landscape, leading to enhanced surface erosion, which provided more transportable material for dust storms. Comparison of the Lake Sayram sediment record with sediment records from other lakes in the region indicates synchronous intervals of enhanced aeolian transport from 1910 to 1930 and 1980 to 2000.

  4. Contamination and Risk Assessment of Heavy Metals in Lake Bed Sediment of a Large Lake Scenic Area in China

    Science.gov (United States)

    Wan, Li; Xu, Liang; Fu, Yongsheng

    2016-01-01

    The exposure of heavy metals to lake bed sediment of scenic areas may pose risks on aquatic ecosystems and human health, however very few studies on risk assessment have been reported for scenic areas. Accordingly, this study determined concentration levels, and assessed contamination characteristics and risks, of heavy metals in lake bed sediment of National Scenic Areas Songhuahu (NSAS) in China. The concentrations of Zn, Cr, Pb, Ni, and Cu were determined in 29 bed sediment samples. Results showed that the mean values of Zn, Cr, Pb, Ni, and Cu were 92.69, 90.73, 38.29, 46.77, and 49.44 mg/kg, respectively. Pearson correlation coefficients indicated that organic matter was a major factor influencing distribution of heavy metals. The results for enrichment factors indicated that contamination rates and anthropogenic inputs of single heavy metals decreased in the order Cu > Ni > Pb > Cr > Zn; results of Nemerow integrated pollution index suggested that 72.41% of sampling sites were exposed to low to moderately integrated pollution, and 27.59% of sampling sites were exposed to strongly integrated pollution. According to results for potential ecological risk index, ecological risks of single and all the heavy metals in bed sediment from all the sampling sites were low. Human risks were assessed with hazardous quotients, and the results suggested that exposure of heavy metals to bed sediment posed no or little risk to human health, and the pathway of ingestion significantly contributed to human health risks. PMID:27455296

  5. The behavior of molybdenum and its isotopes across the chemocline and in the sediments of sulfidic Lake Cadagno, Switzerland

    DEFF Research Database (Denmark)

    Dahl, Tais W.; Anbar, Ariel D.; Gordon, Gwyneth W.

    2010-01-01

    scavenging of Mo when buried into sulfidic sediments. This paper contains the first complete suite of Mo isotope fractionation observations in a sulfidic water column and sediment system, the meromictic Lake Cadagno, Switzerland, a small alpine lake with a pronounced oxygen-sulfide transition reaching up...

  6. BIOGEOCHEMICAL CONTROLS ON REACTION OF SEDIMENTARY ORGANIC MATTER AND AQUEOUS SULFIDES IN HOLOCENE SEDIMENTS OF MUD LAKE FLORIDA

    Science.gov (United States)

    The distribution and quantity of organic sulfur and iron sulfur species were determined in theHolocene sediments from Mud Lake, Florida. The sediments of this shallow, sinkhole lake are characterized by high sulfur and organic carbon contents as well as active sulfate reducti...

  7. Mercury in sediment, water, and fish in a managed tropical wetland-lake ecosystem.

    Science.gov (United States)

    Malczyk, Evan A; Branfireun, Brian A

    2015-08-15

    Mercury pollution has not been well documented in the inland lakes or fishes of Mexico, despite the importance of freshwater fish as a source of protein in local diets. Total mercury and methylmercury in waters, sediments, and the commercial fish catch were investigated in Lake Zapotlán, Mexico. Concentrations of total and methylmercury were very high in runoff and wastewater inputs, but very low in sediments and surface waters of the open water area of the lake. Concentrations of total mercury in tilapia and carp were very low, consistent with the low concentrations in lake water and sediments. Particle settling, sorption, the biogeochemical environment, and/or bloom dilution are all plausible explanations for the significant reductions in both total mercury and methylmercury. Despite very high loading of mercury, this shallow tropical lake was not a mercury-impaired ecosystem, and these findings may translate across other shallow, alkaline tropical lakes. Importantly, the ecosystem services that seemed to be provided by peripheral wetlands in reducing mercury inputs highlight the potential for wetland conservation or restoration in Mexico. Copyright © 2015. Published by Elsevier B.V.

  8. Assessment of Water and Sediment Physical-Chemical Composition in the West Coast of Maracaibo Lake

    Directory of Open Access Journals (Sweden)

    Jorge Moronta-Riera

    2016-05-01

    Full Text Available The objective of this investigation was to determine the physical and chemical composition of the water streams and sediments of the Maracaibo Lake in three sampling areas located in Tía Juana, Lagunillas and Ceuta in order to know the level of contamination and assess water quality based on permissible values established by the 883 Decree. The results indicate that the overall hydrocarbon concentrations in the water and sediments are above permissible levels. It is concluded that petroleum prospection is the root cause of the lake contamination.

  9. {sup 137}Cs and {sup 210}Pb inventories in soils and sediments from Chapala Lake (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Fernandez, A.C.; Perez-Bernal, L.H. [Unidad Academica Mazatlan, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico (Mexico); Sanchez-Cabeza, J.A. [Unidad Academica de Procesos Oceanicos y Costeros, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico (Mexico); Ontiveros-Cuadras, J.F. [Posgrado en Ciencias del Mar y Limnologia, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico (Mexico)

    2014-07-01

    Chapala Lake is the largest natural freshwater reservoir in Mexico and it is located in Central Mexico, at 1524 m above sea level. The lake is considered to be fairly anthropized and it has experienced periods of extremely low water level as a result of recent climate change and water extraction. The study of recent manifestations of global change in Chapala Lake requires accurate {sup 210}Pb chronological reconstructions, taking into account the expected variability of sediment accumulation rates by using the Constant Flux model. For a reliable application of this dating model, it is important that {sup 210}Pb flux values in the lacustrine sedimentary record are in correspondence with the local atmospheric fluxes. With the aim to estimate the fluxes of the fallout radionuclides {sup 210}Pb and {sup 137}Cs in the region, sediment and soil cores were collected in the Chapala Lake. Sediment profiles were evaluated and estimated fluxes in sediments and soils were compared. Some geochemical properties (e.g. grain size distribution, organic matter concentration, XRF-derived elemental composition and magnetic susceptibility) were also evaluated to understand how diagenesis changes and sediment provenance can affect the {sup 210}Pb and {sup 137}Cs depth profiles and inventories. Document available in abstract form only. (authors)

  10. Temperature and cyanobacterial bloom biomass influence phosphorous cycling in eutrophic lake sediments.

    Directory of Open Access Journals (Sweden)

    Mo Chen

    Full Text Available Cyanobacterial blooms frequently occur in freshwater lakes, subsequently, substantial amounts of decaying cyanobacterial bloom biomass (CBB settles onto the lake sediments where anaerobic mineralization reactions prevail. Coupled Fe/S cycling processes can influence the mobilization of phosphorus (P in sediments, with high releases often resulting in eutrophication. To better understand eutrophication in Lake Taihu (PRC, we investigated the effects of CBB and temperature on phosphorus cycling in lake sediments. Results indicated that added CBB not only enhanced sedimentary iron reduction, but also resulted in a change from net sulfur oxidation to sulfate reduction, which jointly resulted in a spike of soluble Fe(II and the formation of FeS/FeS2. Phosphate release was also enhanced with CBB amendment along with increases in reduced sulfur. Further release of phosphate was associated with increases in incubation temperature. In addition, CBB amendment resulted in a shift in P from the Fe-adsorbed P and the relatively unreactive Residual-P pools to the more reactive Al-adsorbed P, Ca-bound P and organic-P pools. Phosphorus cycling rates increased on addition of CBB and were higher at elevated temperatures, resulting in increased phosphorus release from sediments. These findings suggest that settling of CBB into sediments will likely increase the extent of eutrophication in aquatic environments and these processes will be magnified at higher temperatures.

  11. Manganese and iron geochemistry in sediments underlying the redox-stratified Fayetteville Green Lake

    Science.gov (United States)

    Herndon, Elizabeth M.; Havig, Jeff R.; Singer, David M.; McCormick, Michael L.; Kump, Lee R.

    2018-06-01

    Manganese and iron are redox-sensitive elements that yield clues about biogeochemistry and redox conditions both in modern environments and in the geologic past. Here, we investigated Mn and Fe-bearing minerals preserved in basin sediments underlying Fayetteville Green Lake, a redox-stratified lake that serves as a geochemical analogue for Paleoproterozoic oceans. Synchrotron-source microprobe techniques (μXRF, μXANES, and μXRD) and bulk geochemical analyses were used to examine the microscale distribution and speciation of Mn, Fe, and S as a function of depth in the top 48 cm of anoxic lake sediments. Manganese was primarily associated with calcite grains as a manganese-rich carbonate that precipitated in the chemocline of the water column and settled through the euxinic basin to collect in lake sediments. Iron was preserved in framboidal iron sulfides that precipitated in euxinic bottom waters and underwent transformation to pyrite and marcasite in the sediments. Previous studies attribute the formation of manganese-rich carbonates to the diagenetic alteration of manganese oxides deposited in basins underlying oxygenated water. Our study challenges this paradigm by providing evidence that Mn-bearing carbonates form in the water column and accumulate in sediments below anoxic waters. Consequently, manganoan carbonates preserved in the rock record do not necessarily denote the presence of oxygenated bottom waters in ocean basins.

  12. Promise and Pitfalls of Using Grain Size Analysis to Identify Glacial Sediments in Alpine Lake Cores.

    Science.gov (United States)

    Clark, D. H.

    2011-12-01

    Lakes fed by glacier outwash should have a clastic particle-size record distinct from non-glacial lakes in the same area, but do they? The unique turquoise color of alpine glacial lakes reflects the flux of suspended clastic glacial rock flour to those lakes; conversely, lakes not fed by outwash are generally clear with sediments dominated by organics or slope-wash from nearby hillslopes. This contrast in sediment types and sources should produce a distinct and measureable different in grain sizes between the two settings. Results from a variety of lakes suggest the actual situation is often more subtle and complex. I compare grain size results to other proxies to assess the value of grain size analysis for paleoglacier studies. Over the past 10 years, my colleagues and I have collected and analyzed sediment cores from a wide variety of lakes below small alpine glaciers in an attempt to constrain the timing and magnitude of alpine glaciation in those basins. The basic concept is that these lakes act as continuous catchments for any rock flour produced upstream by glacier abrasion; as a glacier grows, the flux of rock flour to the lake will also increase. If the glacier disappears entirely, rock flour deposition will also cease in short order. We have focused our research in basins with simple sedimentologic settings: mostly small, high-altitude, stripped granitic or metamorphic cirques in which the cirque glaciers are the primary source of clastic sediments. In most cases, the lakes are fed by meltwater from a modern glacier, but were ice free during the earlier Holocene. In such cases, the lake cores should record formation of and changes in activity of the glacier upstream. We used a Malvern Mastersizer 2000 laser particle size analyzer for our grain size analyses, as well as recording magnetic susceptibility, color, and organics for the same cores. The results indicate that although lakes often experience increases in silt and clay-size (<0.63 mm) clastic

  13. Fast phosphorus loss by sediment resuspension in a re-established shallow lake on former agricultural fields

    DEFF Research Database (Denmark)

    Kragh, Theis; Sand-Jensen, Kaj; Petersen, Kathrine

    2017-01-01

    Lake restoration on fertilized agricultural fields can lead to extensive nutrient release from flooded soils which can maintain a poor ecological quality in the new lake. The period with high sediment release is poorly understood due to few detailed lake restorations studies. We conducted such a ...

  14. Fast phosphorus loss by sediment resuspension in a re-established shallow lake on former agricultural fields

    DEFF Research Database (Denmark)

    Kragh, Theis; Sand-Jensen, Kaj; Petersen, Kathrine

    2017-01-01

    Lake restoration on fertilized agricultural fields can lead to extensive nutrient release from flooded soils which can maintain a poor ecological quality in the new lake. The period with high sediment release is poorly understood due to few detailed lake restorations studies. We conducted...

  15. Using lead isotopes and trace element records from two contrasting Lake Tanganyika sediment cores to assess watershed – Lake exchange

    Science.gov (United States)

    Odigie, Kingsley; Cohen, A.D.; Swarzenski, Peter W.; Flegal, R

    2014-01-01

    Lead isotopic and trace element records of two contrasting sediment cores were examined to reconstruct historic, industrial contaminant inputs to Lake Tanganyika, Africa. Observed fluxes of Co, Cu, Mn, Ni, Pb, and Zn in age-dated sediments collected from the lake varied both spatially and temporally over the past two to four centuries. The fluxes of trace elements were lower (up to 10-fold) at a mid-lake site (MC1) than at a nearshore site (LT-98-58), which is directly downstream from the Kahama and Nyasanga River watersheds and adjacent to the relatively pristine Gombe Stream National Park. Trace element fluxes at that nearshore site did not measurably change over the last two centuries (1815–1998), while the distal, mid-lake site exhibited substantial changes in the fluxes of trace elements – likely caused by changes in land use – over that period. For example, the flux of Pb increased by ∼300% from 1871 to 1991. That apparent accelerated weathering and detrital mobilization of lithogenic trace elements was further evidenced by (i) positive correlations (r = 0.77–0.99, p factors (EF operations within the lake’s watershed over the past century. The data also indicate that the mid-lake site is a much more sensitive and useful recorder of environmental changes than the nearshore site. Furthermore, the lead isotopic compositions of sediment at the sites differed spatially, indicating that the Pb (and other trace elements by association) originated from different natural sources at the two locations.

  16. Quantification of human-associated fecal indicators reveal sewage from urban watersheds as a source of pollution to Lake Michigan

    Science.gov (United States)

    Olds, Hayley T.; Dila, Deborah K.; Bootsma, Melinda J.; Corsi, Steven; McLellan, Sandra L.

    2016-01-01

    Sewage contamination of urban waterways from sewer overflows and failing infrastructure is a major environmental and public health concern. Fecal coliforms (FC) are commonly employed as fecal indicator bacteria, but do not distinguish between human and non-human sources of fecal contamination. Human Bacteroides and humanLachnospiraceae, two genetic markers for human-associated indicator bacteria, were used to identify sewage signals in two urban rivers and the estuary that drains to Lake Michigan. Grab samples were collected from the rivers throughout 2012 and 2013 and hourly samples were collected in the estuary across the hydrograph during summer 2013. Human Bacteroides and human Lachnospiraceae were highly correlated with each other in river samples (Pearson’s r = 0.86), with average concentrations at most sites elevated during wet weather. These human indicators were found during baseflow, indicating that sewage contamination is chronic in these waterways. FC are used for determining total maximum daily loads (TMDLs) in management plans; however, FC concentrations alone failed to prioritize river reaches with potential health risks. While 84% of samples with >1000 CFU/100 ml FC had sewage contamination, 52% of samples with moderate (200–1000 CFU/100 ml) and 46% of samples with low (events and was highest during an event with a short duration of intense rain. This work demonstrates urban areas have unrecognized sewage inputs that may not be adequately prioritized for remediation by the TMDL process. Further analysis using these approaches could determine relationships between land use, storm characteristics, and other factors that drive sewage contamination in urban waterways.

  17. A Microbial Signature Approach to Identify Fecal Pollution in the Waters Off an Urbanized Coast of Lake Michigan

    Science.gov (United States)

    Newton, Ryan J.; Bootsma, Melinda J.; Morrison, Hilary G.; Sogin, Mitchell L.

    2014-01-01

    Urban coasts receive watershed drainage from ecosystems that include highly developed lands with sewer and stormwater infrastructure. In these complex ecosystems, coastal waters are often contaminated with fecal pollution, where multiple delivery mechanisms that often contain multiple fecal sources make it difficult to mitigate the pollution. Here, we exploit bacterial community sequencing of the V6 and V6V4 hypervariable regions of the bacterial 16S rRNA gene to identify bacterial distributions that signal the presence of sewer, fecal, and human fecal pollution. The sequences classified to three sewer infrastructure-associated bacterial genera, Acinetobacter, Arcobacter, and Trichococcus, and five fecal-associated bacterial families, Bacteroidaceae, Porphyromonadaceae, Clostridiaceae, Lachnospiraceae, and Ruminococcaceae, served as signatures of sewer and fecal contamination, respectively. The human fecal signature was determined with the Bayesian source estimation program SourceTracker, which we applied to a set of 40 sewage influent samples collected in Milwaukee, WI, USA to identify operational taxonomic units (≥97 % identity) that were most likely of human fecal origin. During periods of dry weather, the magnitudes of all three signatures were relatively low in Milwaukee's urban rivers and harbor and nearly zero in Lake Michigan. However, the relative contribution of the sewer and fecal signature frequently increased to >2 % of the measured surface water communities following sewer overflows. Also during combined sewer overflows, the ratio of the human fecal pollution signature to the fecal pollution signature in surface waters was generally close to that of sewage, but this ratio decreased dramatically during dry weather and rain events, suggesting that nonhuman fecal pollution was the dominant source during these weather-driven scenarios. The qPCR detection of two human fecal indicators, human Bacteroides and Lachno2, confirmed the urban fecal footprint in

  18. Complex postglacial recolonization inferred from population genetic structure of mottled sculpin Cottus bairdii in tributaries of eastern Lake Michigan, U.S.A.

    Science.gov (United States)

    Homola, J J; Ruetz, C R; Kohler, S L; Thum, R A

    2016-11-01

    This study used analyses of the genetic structure of a non-game fish species, the mottled sculpin Cottus bairdii to hypothesize probable recolonization routes used by cottids and possibly other Laurentian Great Lakes fishes following glacial recession. Based on samples from 16 small streams in five major Lake Michigan, U.S.A., tributary basins, significant interpopulation differentiation was documented (overall F ST = 0·235). Differentiation was complex, however, with unexpectedly high genetic similarity among basins as well as occasionally strong differentiation within basins, despite relatively close geographic proximity of populations. Genetic dissimilarities were identified between eastern and western populations within river basins, with similarities existing between eastern and western populations across basins. Given such patterns, recolonization is hypothesized to have occurred on three occasions from more than one glacial refugium, with a secondary vicariant event resulting from reduction in the water level of ancestral Lake Michigan. By studying the phylogeography of a small, non-game fish species, this study provides insight into recolonization dynamics of the region that could be difficult to infer from game species that are often broadly dispersed by humans. © 2016 The Fisheries Society of the British Isles.

  19. Characteristics of sediment resuspension in Lake Taihu, China: A wave flume study

    Science.gov (United States)

    Ding, Yanqing; Sun, Limin; Qin, Boqiang; Wu, Tingfeng; Shen, Xia; Wang, Yongping

    2018-06-01

    Lake Taihu is a typical shallow lake which frequently happens sediment resuspension induced by wind-induced waves. The experiments are carried on to simulate the wave disturbance processes in wave flume by setting a series of wave periods (1.2 s, 1.5 s, 1.8 s) and wave heights (2 cm, 10 cm). It aims to analyze the characteristics of sediment resuspension and the mechanisms of nutrients release and to evaluate the effects of sediment dredging on sediment resuspension and nutrients release in Lake Taihu. The results show that wave shear stress during 2 cm and 10 cm wave height processes ranges 0.018-0.023 N/m2 and 0.221-0.307 N/m2, respectively. Wave shear stress has no significant differences between wave periods. Wave height has much more effects on sediment resuspension. Wave height of 2 cm could induce total suspended solids (TSS) reaching up to 5.21 g/m2 and resuspension flux of sediment (M) up to 1.74 g/m2. TSS sharply increases to 30.33-52.41 g/m2 and M reached up to 48.94 g/m2 when wave height reaches to 10 cm. The disturbance depth under different sediment bulk weights ranges from 0.089 to 0.161 mm. Variation of suspended solids in 3 layers (1 cm, 5 cm, 20 cm above sediment interface) has no significant differences. Organic matter, TN and TP have positive relationship with SS. Organic matter is only accounted for 5.7%-7.3% of SS. The experiments under different sediment bulk densities (1.34 g/cm3, 1.47 g/cm3 and 1.59 g/cm3) find that TSS and M fall by 44.2% and 39.8% with sediment bulk density increasing, respectively. Total TN, DTN, TP and DTP decrease by 24.3%-33.6%. It indicates that sediment dredging could effectively reduce SS concentration and nutrient levels in water column. The researches provide a theoretical basis for sediment dredging to control the shore zone of Lake Taihu for lake management.

  20. Information from uranium and thorium isotopes recorded in lake bottom sediment - Lake Kawaguchi. Attempt to evaluate environmental changes

    International Nuclear Information System (INIS)

    Sakaguchi, A.; Yamamoto, M.; Shimizu, T.; Sasaki, K.; Koshimizu, S.

    2003-01-01

    Lake sediments, as well as ice cores and marine sediments, have been used to reveal past environmental changes caused by both natural and artificial events with local and global scales. Particles in the lake originate from soil and other suspended matter which are carried in from the inflowing water or from direct discharge (lithogenous particles), and they are also formed in the lake as a result of the growth, metabolism and death of plants and animals (autogenous particles). The settling particles contain U and Th isotopes due to lithogenous particles (soil), and adsorbed U to the particles. Thorium has an exceedingly low solubility in water and is very strongly adsorbed onto particles. If we can distinguish these two different components in the mixture of U due to lithogenous particles themselves and adsorption fractions, the former might provide useful information on past environmental changes by natural events, while the latter information on past environmental changes by artificial events. In this paper, we aimed to test the above hypothesis using data on U and Th isotopes of sediment cores (0- ca. 40 cm depth, covering periods of past several hundred years) from 3 points in Lake Kawaguchi of Fuji-Goko in Japan. By using model equation and results obtained from analysis, we distinguished U due to lithogenous and autogenous particles. And these depth profiles were compared with changes in the rainfall during the period of 1933 - 2001. Although the changes in the 238 U/ 232 Th ratios with depth for lithogenous particles and rainfall do not fluctuate synchronously, some parts of depth coincided with each other. The results suggest strongly that variation in the U and Th isotopic ratios separated by model might be helpful in tracing the past environmental changes in regional scale. To check the usefulness of this method, physical and chemical data such as grain size, grain density, water content and biogenic SiO 2 in the sediment will be further compared with the

  1. Lake depth rather than fish planktivory determines cladoceran community structure in Faroese lakes - evidence from contemporary data and sediments

    DEFF Research Database (Denmark)

    Amsinck, S.L.; Strzelczak, A.; Bjerring, R.

    2006-01-01

    development was inferred by cladoceran-based paleolimnological investigations of a 14C-dated sediment core covering the last ca 5700 years. 3. The 29 study lakes were overall shallow, small-sized, oligotrophic and dominated by brown trout (Salmo trutta). Cladoceran species richness was overall higher...... depth. A recent increase in inferred Zmax may, however, be an artefact induced by, for instance, eutrophication....

  2. Reconnaissance Study for the Western Lake Huron Basin, Watershed Study, Michigan, Section 905(b)

    Science.gov (United States)

    2012-05-01

    North and South Branch  v. Important for Walleye spawning  b. Install sediment traps  c. Promote 10 foot filter strips for  farmers     Page 2 of 8    d...goal to have 85% of livestock  farmers  meeting standards  ii. New legislation    15. Existing ordinances  a. Lack of staffing/resources to enforce  b. No...Jamie McCombs, Chairman/Member  Village of Lexington Environmental  Committee/Sanilac County Watershed Advisory  Council  5689 Old  Orchard  Bluff

  3. Integrated synoptic surveys of the hydrodynamics and water-quality distributions in two Lake Michigan rivermouth mixing zones using an autonomous underwater vehicle and a manned boat

    Science.gov (United States)

    Jackson, P. Ryan; Reneau, Paul C.

    2014-01-01

    The U.S. Geological Survey (USGS), in cooperation with the National Monitoring Network for U.S. Coastal Waters and Tributaries, launched a pilot project in 2010 to determine the value of integrated synoptic surveys of rivermouths using autonomous underwater vehicle technology in response to a call for rivermouth research, which includes study domains that envelop both the fluvial and lacustrine boundaries of the rivermouth mixing zone. The pilot project was implemented at two Lake Michigan rivermouths with largely different scales, hydrodynamics, and settings, but employing primarily the same survey techniques and methods. The Milwaukee River Estuary Area of Concern (AOC) survey included measurements in the lower 2 to 3 miles of the Milwaukee, Menomonee, and Kinnickinnic Rivers and inner and outer Milwaukee Harbor. This estuary is situated in downtown Milwaukee, Wisconsin, and is the most populated basin that flows directly into Lake Michigan. In contrast, the Manitowoc rivermouth has a relatively small harbor separating the rivermouth from Lake Michigan, and the Manitowoc River Watershed is primarily agricultural. Both the Milwaukee and Manitowoc rivermouths are unregulated and allow free exchange of water with Lake Michigan. This pilot study of the Milwaukee River Estuary and Manitowoc rivermouth using an autonomous underwater vehicle (AUV) paired with a manned survey boat resulted in high spatial and temporal resolution datasets of basic water-quality parameter distributions and hydrodynamics. The AUV performed well in these environments and was found primarily well-suited for harbor and nearshore surveys of three-dimensional water-quality distributions. Both case studies revealed that the use of a manned boat equipped with an acoustic Doppler current profiler (ADCP) and multiparameter sonde (and an optional flow-through water-quality sampling system) was the best option for riverine surveys. To ensure that the most accurate and highest resolution velocity data

  4. A mathematical model for lake ontogeny in terms of filling with sediments and macrophyte vegetation

    International Nuclear Information System (INIS)

    Brydsten, Lars

    2004-05-01

    A mathematical model for simulation of lake basin filling processes in areas with positive shore displacement was constructed. The model was calibrated using sediment and catchments data from eight existing lake basins situated in the northern coastal area of the province of Uppland, Sweden. The lake basin filling processes were separated into three phases: basin filling with wave-washed material (silt, silty sand or sand), filling with fine-grained material during the shallow gulf and lake stages, respectively, and filling with vegetation during the lake stage. The basin filling rates for wave-washed material were generally low but varied considerably both between and within lakes. The mean basin filling rate of wave-washed material was 4.1%. The volume of inorganic sediments produced, and basin filling rates during the shallow gulf and lake phases were determined for all the eight lakes. The relationship between basin filling rate and parameters describing the catchments, the former postglacial basins and the lakes, respectively, was determined using multiple regression analysis. The basin filling rate with inorganic sediments was best described by parameters related to former postglacial basin morphometry and current lake morphometry, e.g. basin volume, lake volume, and lake area. The goodness of fit turned out to be 0.99 for a simple regression with basin volume as the sole independent variable. The basin filling with vegetation (Phragmites australis followed by Sphagnum spp.) was treated as a 2-dimensional process. A dataset with 84 bogs was selected from a digital soil map. The ages of the bogs were calculated using a digital elevation map and an equation for shore displacement. The choke-up rate was then calculated by dividing the area of the bogs with their age. A strong exponential relationship exists between areas of the bogs and choke-up rat, and this relationship was then used in the model. The resulting model starts by filling the former coastal basin

  5. A mathematical model for lake ontogeny in terms of filling with sediments and macrophyte vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Brydsten, Lars [Umeaa Univ. (Sweden). Dept. of Biology and Environmental Science

    2004-05-01

    A mathematical model for simulation of lake basin filling processes in areas with positive shore displacement was constructed. The model was calibrated using sediment and catchments data from eight existing lake basins situated in the northern coastal area of the province of Uppland, Sweden. The lake basin filling processes were separated into three phases: basin filling with wave-washed material (silt, silty sand or sand), filling with fine-grained material during the shallow gulf and lake stages, respectively, and filling with vegetation during the lake stage. The basin filling rates for wave-washed material were generally low but varied considerably both between and within lakes. The mean basin filling rate of wave-washed material was 4.1%. The volume of inorganic sediments produced, and basin filling rates during the shallow gulf and lake phases were determined for all the eight lakes. The relationship between basin filling rate and parameters describing the catchments, the former postglacial basins and the lakes, respectively, was determined using multiple regression analysis. The basin filling rate with inorganic sediments was best described by parameters related to former postglacial basin morphometry and current lake morphometry, e.g. basin volume, lake volume, and lake area. The goodness of fit turned out to be 0.99 for a simple regression with basin volume as the sole independent variable. The basin filling with vegetation (Phragmites australis followed by Sphagnum spp.) was treated as a 2-dimensional process. A dataset with 84 bogs was selected from a digital soil map. The ages of the bogs were calculated using a digital elevation map and an equation for shore displacement. The choke-up rate was then calculated by dividing the area of the bogs with their age. A strong exponential relationship exists between areas of the bogs and choke-up rat, and this relationship was then used in the model. The resulting model starts by filling the former coastal basin

  6. Geochemical Dataset of the Rhone River Delta (Lake Geneva) Sediments - Disentangling Human Impacts from Climate Change

    Science.gov (United States)

    Silva, T. A.; Girardclos, S.; Loizeau, J. L.

    2016-12-01

    Lake sediment records are often the most complete continental archives. In the last 200 years, in addition to climatic variability, humans have strongly impacted lake watersheds around the world. During the 20th century the Rhone River and its watershed upstream Lake Geneva (Switzerland/France) have been subject to river channelization, dam construction, water flow regulation, water and sediment abstraction as well as various land use changes. Under the scope of the SEDFATE project (Swiss National Science Foundation nº147689) we address human and climatic impact on the sediment transfer from the Rhone River watershed to Lake Geneva. Nineteen short sediment cores were collected in the Rhone River delta area in May 2014. Cores have been scanned with MSCL and XRF, sub-sampled every 1cm and 8 cores were dated by radiometric methods (137Cs and 210Pb). Photographs taken right after core opening were used for lithological description and in addition to MSCL data were used to correlate cores. Core dating shows that mass accumulation rates decreased in the 1964-1986 interval and then increased again in the interval between 1986-2014. XRF elements and ratios, known to indicate detrital sources (Al, Al/Si, Fe, K, Mn, Rb, Si, Ti, Ti/Ca), show that clastic input diminished from 1964 to 1986 and re-increased to the present. Other elemental (Zr/Rb, Zr/K, Si/Ti) and geophysical data (magnetic susceptibility) combined with lithology identify density flow deposits vs hemipelagic sedimentation. Changes in frequency of these event deposits indicate changes in the sedimentation patterns in the Rhone River sublacustrine delta during the last century. From these results we hypothesize that a significant sediment amount was abstracted from the system after the major dam constructions in the 1950's and that, since the 1990's, a contrary signal is due to increased sediment loads that follows glacial melting due to global warming.

  7. Total mercury concentrations in surface water and sediments from Danube Delta lakes

    Directory of Open Access Journals (Sweden)

    TEODOROF Liliana

    2007-10-01

    Full Text Available The samples were collected from surface water and sediments of Danube Delta lakes, during april and may 2006. The sediments were digested with nitric acid, and the surface water with real aqua, at Microwave Oven Anton Paar and analised at FIMS 400 Perkin Elmer. The results show that the total mercury is compared with the maximum allowed limits according with Normative 161/2006.

  8. Sources of anthropogenic lead in sediments from an artificial lake in Brasilia-central Brazil

    International Nuclear Information System (INIS)

    Gioia, S.M.C.L.; Pimentel, M.M.; Tessler, M.; Dantas, E.L.; Campos, J.E.G.; Guimaraes, E.M.; Maruoka, M.T.S.; Nascimento, E.L.C.

    2006-01-01

    Pb concentration and Pb isotopic composition are known to represent powerful tools to investigate the history of Pb pollution in water and sediments. In this paper, we present and discuss the results of a detailed study of sediments deposited in the Paranoa Lake, a 44-year-old artificial reservoir in Brasilia, central Brazil. Pb concentration and isotopic composition of the sediments were obtained by ID-TIMS, on three different sample fractions: leachate, residue, and bulk sample. The leachate phase has proven to be most efficient to distinguish between anthropogenic and natural Pb inputs. In the Paranoa lake, important sources of contamination were recognized, producing higher Pb concentrations (max. 37.68 ppm) and significant variations in Pb isotopic composition, relative to the regional geogenic background. Contamination of the sediments due to anthropogenic activity produced less radiogenic Pb isotopic compositions ( 206 Pb/ 207 Pb = 1.15-1.17), compared with the regional natural composition ( 206 Pb/ 207 Pb = 1.19-1.25). 21 Pb analyses along one bore hole which sampled the entire sediment section indicated a sedimentation rate of 8.2 ± 1.8 mm/year. The combined use of the 21 Pb ages and Pb isotopic compositions of these samples revealed three distinct periods in the lake history: (1) the period of the time formation of the lake in 1959 until ca. 1970 was characterized by the deposition of sediments displaying more radiogenic Pb isotopic signature, (2) the time interval from the start of the process of eutrophication at 1970, until 1995, was characterized by the deposition of sediments having less radiogenic average compositions, and (3) from 1995 until the present represents a period of recovery of water quality, after two sewage treatment stations started to operate

  9. Sediment nitrogen cycling rates and microbial abundance along a submerged vegetation gradient in a eutrophic lake.

    Science.gov (United States)

    Yao, Lu; Chen, Chengrong; Liu, Guihua; Liu, Wenzhi

    2018-03-01

    Decline of submerged vegetation is one of the most serious ecological problems in eutrophic lakes worldwide. Although restoration of submerged vegetation is widely assumed to enhance ecological functions (e.g., nitrogen removal) and aquatic biodiversity, the evidence for this assumption is very limited. Here, we investigated the spatio-temporal patterns of sediment potential nitrification, unamended denitrification and N 2 O production rates along a vegetation gradient in the Lake Honghu, where submerged vegetation was largely restored by prohibiting net-pen aquaculture. We also used five functional genes as markers to quantify the abundance of sediment nitrifying and denitrifying microorganisms. Results showed that unvegetated sediments supported greater nitrification rates than rhizosphere sediments of perennial or seasonal vegetation. However, the absence of submerged vegetation had no significant effect on denitrification and N 2 O production rates. Additionally, the abundance of functional microorganisms in sediments was not significantly different among vegetation types. Season had a strong effect on both nitrogen cycling processes and microbial abundances. The highest nitrification rates were observed in September, while the highest denitrification rates occurred in December. The temporal variation of sediment nitrification, denitrification and N 2 O production rates could be due to changes in water quality and sediment properties rather than submerged vegetation and microbial abundances. Our findings highlight that vegetation restoration in eutrophic lakes improves water quality but does not enhance sediment nitrogen removal rates and microbial abundances. Therefore, for reducing the N level in eutrophic lakes, major efforts should be made to control nutrients export from terrestrial ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The Influence of Macrophytes on Sediment Resuspension and the Effect of Associated Nutrients in a Shallow and Large Lake (Lake Taihu, China)

    Science.gov (United States)

    Zhu, Mengyuan; Zhu, Guangwei; Nurminen, Leena; Wu, Tingfeng; Deng, Jianming; Zhang, Yunlin; Qin, Boqiang; Ventelä, Anne-Mari

    2015-01-01

    A yearlong campaign to examine sediment resuspension was conducted in large, shallow and eutrophic Lake Taihu, China, to investigate the influence of vegetation on sediment resuspension and its nutrient effects. The study was conducted at 6 sites located in both phytoplankton-dominated zone and macrophyte-dominated zone of the lake, lasting for a total of 13 months, with collections made at two-week intervals. Sediment resuspension in Taihu, with a two-week high average rate of 1771 g·m-2·d-1 and a yearly average rate of 377 g·m-2·d-1, is much stronger than in many other lakes worldwide, as Taihu is quite shallow and contains a long fetch. The occurrence of macrophytes, however, provided quite strong abatement of sediment resuspension, which may reduce the sediment resuspension rate up to 29-fold. The contribution of nitrogen and phosphorus to the water column from sediment resuspension was estimated as 0.34 mg·L-1 and 0.051 mg·L-1 in the phytoplankton-dominated zone. Sediment resuspension also largely reduced transparency and then stimulated phytoplankton growth. Therefore, sediment resuspension may be one of the most important factors delaying the recovery of eutrophic Lake Taihu, and the influence of sediment resuspension on water quality must also be taken into account by the lake managers when they determine the restoration target. PMID:26030094

  11. Salinity Affects the Composition of the Aerobic Methanotroph Community in Alkaline Lake Sediments from the Tibetan Plateau.

    Science.gov (United States)

    Deng, Yongcui; Liu, Yongqin; Dumont, Marc; Conrad, Ralf

    2017-01-01

    Lakes are widely distributed on the Tibetan Plateau, which plays an important role in natural methane emission. Aerobic methanotrophs in lake sediments reduce the amount of methane released into the atmosphere. However, no study to date has analyzed the methanotroph community composition and their driving factors in sediments of these high-altitude lakes (>4000 m). To provide new insights on this aspect, the abundance and composition in the sediments of six high-altitude alkaline lakes (including both freshwater and saline lakes) on the Tibetan Plateau were studied. The quantitative PCR, terminal restriction fragment length polymorphism, and 454-pyrosequencing methods were used to target the pmoA genes. The pmoA gene copies ranged 10 4 -10 6 per gram fresh sediment. Type I methanotrophs predominated in Tibetan lake sediments, with Methylobacter and uncultivated type Ib methanotrophs being dominant in freshwater lakes and Methylomicrobium in saline lakes. Combining the pmoA-pyrosequencing data from Tibetan lakes with other published pmoA-sequencing data from lake sediments of other regions, a significant salinity and alkalinity effect (P = 0.001) was detected, especially salinity, which explained ∼25% of methanotroph community variability. The main effect was Methylomicrobium being dominant (up to 100%) in saline lakes only. In freshwater lakes, however, methanotroph composition was relatively diverse, including Methylobacter, Methylocystis, and uncultured type Ib clusters. This study provides the first methanotroph data for high-altitude lake sediments (>4000 m) and shows that salinity is a driving factor for the community composition of aerobic methanotrophs.

  12. Methanogenesis in the sediment of the acidic Lake Caviahue in Argentina

    Science.gov (United States)

    Koschorreck, Matthias; Wendt-Potthoff, Katrin; Scharf, Burkhard; Richnow, Hans H.

    2008-12-01

    The biogeochemistry of methane in the sediments of Lake Caviahue was examined by geochemical analysis, microbial activity assays and isotopic analysis. The pH in the water column was 2.6 and increased up to a pH of 6 in the deeper sediment pore waters. The carbon isotope composition of CH 4 was between - 65 and - 70‰ which is indicative for the biological origin of the methane. The enrichment factor ɛ increased from - 46‰ in the upper sediment column to more than - 80 in the deeper sediment section suggesting a transition from acetoclastic methanogenesis to CO 2 reduction with depth. In the most acidic surface layer of the sediment (pH Copahue Volcano, supported high rates of sulfate reduction which probably raised the pH and created favorable conditions for methanogens in deeper sediment layers.

  13. Biota sediment concentration ratio (CRs-b) for fishes of Rana Pratap Sagar Lake, Rawatbhata

    International Nuclear Information System (INIS)

    Goyal, S.K.; Srivastava, A.P.; Jain, A.K.; Meenal, Balram; Tiwari, S.N.; Ravi, P.M.; Tripathi, R.M.

    2018-01-01

    Radionuclides dissolved in water can be adsorbed by bottom/shore sediment transferring it to the deep sediment layers. These adsorbed radionuclides can be remobilized and be available again for uptake by freshwater biota. The biota sediment concentration ratio (CR s-b ) is the ratio of the concentration of a radionuclide in an organism (C b ) on a fresh weight basis to the radionuclide concentration measured in the sediment (C sediment ). Using the data of 137 Cs activity in fish and shore sediment, CR s-b was calculated for fish samples of Rana Pratap Sagar (RPS) Lake, Rawatbhata. This value can be applied in predictive models to calculate radionuclide concentration in fish samples

  14. Genetic variation in bacterial kidney disease (BKD) susceptibility in Lake Michigan Chinook Salmon and its progenitor population from the Puget Sound

    Science.gov (United States)

    Purcell, Maureen K.; Hard, Jeffrey J.; Neely, Kathleen G.; Park, Linda K.; Winton, James R.; Elliott, Diane G.

    2014-01-01

    Mass mortality events in wild fish due to infectious diseases are troubling, especially given the potential for long-term, population-level consequences. Evolutionary theory predicts that populations with sufficient genetic variation will adapt in response to pathogen pressure. Chinook Salmon Oncorhynchus tshawytscha were introduced into Lake Michigan in the late 1960s from a Washington State hatchery population. In the late 1980s, collapse of the forage base and nutritional stress in Lake Michigan were thought to contribute to die-offs of Chinook Salmon due to bacterial kidney disease (BKD). Previously, we demonstrated that Lake Michigan Chinook Salmon from a Wisconsin hatchery have greater survival following BKD challenge relative to their progenitor population. Here, we evaluated whether the phenotypic divergence of these populations in BKD susceptibility was due to selection rather than genetic drift. Comparison of the overall magnitude of quantitative trait to neutral marker divergence between the populations suggested selection had occurred but a direct test of quantitative trait divergence was not significant, preventing the rejection of the null hypothesis of differentiation through genetic drift. Estimates of phenotypic variation (VP), additive genetic variation (VA) and narrow-sense heritability (h2) were consistently higher in the Wisconsin relative to the Washington population. If selection had acted on the Wisconsin population there was no evidence of a concomitant loss of genetic variation in BKD susceptibility. The Renibacterium salmoninarum exposures were conducted at both 14°C and 9°C; the warmer temperature accelerated time to death in both populations and there was no evidence of phenotypic plasticity or a genotype-by-environment (G × E) interaction. High h2 estimates for BKD susceptibility in the Wisconsin population, combined with a lack of phenotypic plasticity, predicts that future adaptive gains in BKD resistance are still possible and

  15. On the radiocesium carbonate barrier in organics-rich sediments of Lake Juodis, Lithuania

    International Nuclear Information System (INIS)

    Tarasiuk, N.; Koviazina, E.; Kubareviciene, V.; Shliahtich, E.

    2007-01-01

    Radiocesium vertical profiles in organics-rich sediments of running shallow eutrophic Lake Juodis (Lithuania) were studied in relation to seasonal variations of vertical profiles (in water column and sediments) of standard variables (pH, redox potential, temperature, oxygen concentrations, conductivity). It is shown that the sedimentation rate, radiocesium mobility and its vertical profiles in sediments are controlled by the vital cycle (processes of the growth, accumulation and decomposition) of green algae covering the main bottom areas of the lake. It is also shown that calcite deposits are formed in the shallow bottom areas that are oxygenated throughout the year because of the photosynthetic activity of the green algae covering the sediment. Formation of the calcite coatings on freshly accumulated organics is remarkable for causing elevated densities of sediment solids in the upper part of the respective vertical profiles. These calcite deposits behave as a barrier for radiocesium backward flux to the bottom water making the respective bottom areas a radionuclide sink. Together with the jelly-structured sediments lying below these deposits, the calcite preserves the shape of the primary radiocesium vertical profiles formed due to free-ion diffusion after the deposition event. It was determined that bottom areas anaerobic in winter are the main radiocesium source in the water column and cause characteristic radiocesium redistribution in surface sediments

  16. Effects of hurricanes Katrina and Rita on the chemistry of bottom sediments in Lake Pontchartrain, Louisiana, USA

    Science.gov (United States)

    Van Metre, P.C.; Horowitz, A.J.; Mahler, B.J.; Foreman, W.T.; Fuller, C.C.; Burkhardt, M.R.; Elrick, K.A.; Furlong, E.T.; Skrobialowski, S.C.; Smith, J.J.; Wilson, J.T.; Zaugg, S.D.

    2006-01-01

    The effects of Hurricanes Katrina and Rita and the subsequent unwatering of New Orleans, Louisiana, on the sediment chemistry of Lake Pontchartrain were evaluated by chemical analysis of samples of street mud and suspended and bottom sediments. The highest concentrations of urban-related elements and compounds (e.g., Pb, Zn, polycyclic aromatic hydrocarbons, and chlordane) in bottom sediments exceeded median concentrations in U.S. urban lakes and sediment-quality guidelines. The extent of the elevated concentrations was limited, however, to within a few hundred meters of the mouth of the 17th Street Canal, similar to results of historical assessments. Chemical and radionuclide analysis of pre- and post-Hurricane Rita samples indicates that remobilization of near-shore sediment by lake currents and storms is an ongoing process. The effects of Hurricanes Katrina and Rita on the sediment chemistry of Lake Pontchartrain are limited spatially and are most likely transitory. ?? 2006 American Chemical Society.

  17. Results of submerged sediment core sampling and analysis on Par Pond, Pond C, and L Lake: July 1995

    International Nuclear Information System (INIS)

    Koch, J.W. II; Martin, F.D.; Friday, G.P.

    1996-06-01

    Sediment cores from shallow and deep water locations in Par Pond, Pond C, and L Lake were collected and analyzed in 1995 for radioactive and nonradioactive constituents. This core analysis was conducted to develop a defensible characterization of contaminants found in the sediments of Par Pond, Pond C, and L Lake. Mercury was the only nonradiological constituent with a nonestimated quantity that was detected above the U.S Environmental Protection Agency Region IV potential contaminants of concern screening criteria. It was detected at a depth of 0.3--0.6 meters (1.0--2.0 feet) at one location in L Lake. Cesium-137, promethium-146, plutonium-238, and zirconium-95 had significantly higher concentrations in Par Pond sediments than in sediments from the reference sites. Cobalt-60, cesium-137, plutonium-238, plutonium-239/240, and strontium-90 had significantly higher concentrations in L-Lake sediments than sediments from the reference sites

  18. The Legacy of Arsenic Contamination from Giant Mine, Northern Canada: An Assessment of Impacts Based on Lake Water and Lake Sediment Core Analysis

    Science.gov (United States)

    Blais, J. M.; Korosi, J.

    2016-12-01

    The Giant Mine, which operated between 1948 and 2004 and located near the City of Yellowknife (Northwest Territories, Canada), has left a legacy of arsenic, antimony, and mercury contamination extending to the present day. Over 20,000 tonnes of arsenic trioxide dust was released from roaster stack emissions during its first 10 years of operations, leading to a significant contamination of the surrounding landscape. Here we present a summary of impacts by the recent contamination from Giant Mine on the surrounding region. A survey we conducted of 25 lakes of the region in 2010 revealed that most lake water within a 15 km radius of the roaster stack had arsenic concentrations in water > 10 mg/L, the standard for drinking water, with concentrations declining exponentially with increasing distance from the roaster stack. Sediment cores from lakes were collected near the Giant Mine roaster stack and radiometrically dated by 137Cs and excess 210Pb. Arsenic concentrations in these sediments increased by 1700% during the 1950s and 60s, consistent with the history of arsenic releases from roaster emissions. Correspondingly, pelagic diatoms and cladocerans were extirpated from one lake during this period, based on microfossil analysis of lake sediment deposits. Sediment core analysis further showed that this lake ecosystem has not recovered, even ten years after closure of the mine. Likely causes for the lack of recent recovery are explored with the use of sediment toxicity bioassays, using a novel paleo-ecotoxicological approach of using toxicity assessments of radiometrically dated lake sediment horizons.

  19. A comparison of sediment toxicity test methods at three Great Lake Areas of Concern

    Science.gov (United States)

    Burton, G. Allen; Ingersoll, Christopher G.; Burnett, LouAnn C.; Henry, Mary; Hinman, Mark L.; Klaine, Stephen J.; Landrum, Peter F.; Ross, Phillipe; Tuchman, Marc

    1996-01-01

    The significance of sediment contamination is often evaluated using sediment toxicity (bioassay) testing. There are relatively few “standardized” test methods for evaluating sediments. Popular sediment toxicity methods examine the extractable water (elutriate), interstitial water, or whole (bulk) sediment phases using test species spanning the aquatic food chain from bacteria to fish. The current study was designed to evaluate which toxicity tests were most useful in evaluations of sediment contamination at three Great Lake Areas of Concern. Responses of 24 different organisms including fish, mayflies, amphipods, midges, cladocerans, rotifers, macrophytes, algae, and bacteria were compared using whole sediment or elutriate toxicity assays. Sediments from several sites in the Buffalo River, Calumet River (Indiana Harbor), and Saginaw River were tested, as part of the U.S. Environmental Protection Agency's (USEPA) Assessment and Remediation of Contaminated Sediments (ARCS) Project. Results indicated several assays to be sensitive to sediment toxicity and able to discriminate between differing levels of toxicity. Many of the assay responses were significantly correlated to other toxicity responses and were similar based on factor analysis. For most applications, a test design consisting of two to three assays should adequately detect sediment toxicity, consisting of various groupings of the following species: Hyalella azteca, Ceriodaphnia dubia, Chironomus riparius, Chironomus tentans, Daphnia magna, Pimephales promelas, Hexagenia bilineata, Diporeia sp., Hydrilla verticillata, or Lemna minor.

  20. Historical analysis of salmon-derived polychlorinated biphenyls (PCBs) in lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Kruemmel, Eva M. [Inuit Circumpolar Council (ICC), Canada Office, 75 Albert St., Suite 1001, Ottawa, Ontario, K1P 5E7 (Canada)], E-mail: eva_kruemmel@hotmail.com; Scheer, Michael [Scheer Software Solutions, 6 Coghlan Lane, P.O. Box 86, Barry' s Bay, Ontario, K0J 1B0 (Canada); Gregory-Eaves, Irene [Department of Biology, McGill University, Montreal, Quebec, H3A 1B1 (Canada); Macdonald, Robie W. [Department of Fisheries and Oceans, Institute of Ocean Sciences, Sidney, British Columbia, V8L 4B2 (Canada); Kimpe, Lynda E. [Department of Biology, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, K1N 6N5 (Canada); Smol, John P. [Paleoecological Environmental Assessment and Research Laboratory, Department of Biology, Queen' s University, 10 Kingston, Ontario, K7L 3N6 (Canada); Finney, Bruce [Department of Biological Sciences, Idaho State University, Pocatello, ID 83209 (United States); Blais, Jules M. [Department of Biology, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, K1N 6N5 (Canada)

    2009-03-01

    Several recent studies have highlighted the importance of salmon as a means to deliver biomagnifying contaminants to nursery lakes. There is a lack of studies, however, which demonstrate empirically how this source has varied through time. This is of great significance because past salmon-derived contaminant loading was potentially greater than it is today. By analyzing radiometrically dated sediment cores collected from ten lakes in Alaska and British Columbia (B.C.), we relate historical numbers of sockeye salmon spawners to {sigma}PCB concentrations and {delta}{sup 15}N values (a paleolimnological proxy for past salmon-derived nitrogen) in the sediments. The results confirm that sockeye salmon have provided an important route for PCBs to enter the lakes in the past, a finding that is especially evident when the data of all lakes are pooled. Significant relationships between sockeye salmon numbers and {delta}{sup 15}N, as well as {sigma}PCB concentrations and {delta}{sup 15}N in sediments, were also found. However, it is difficult to establish relationships between salmon numbers, {sigma}PCBs and {delta}{sup 15}N in individual lakes. This may be due to a number of factors which may influence contaminant loadings to the lakes. The factors include: a) changing salmon contaminant loads over time resulting from a lag in the upper ocean reservoir and/or changing salmon feeding locations; b) greater importance of atmospheric transport in lakes with relatively low salmon returns; and c) increased PCB scavenging due to higher algae productivity in the lakes in recent years.

  1. Spatial distribution and risk assessment of heavy metals and As pollution in the sediments of a shallow lake.

    Science.gov (United States)

    Deng, Jiancai; Wang, Yuansheng; Liu, Xin; Hu, Weiping; Zhu, Jinge; Zhu, Lin

    2016-05-01

    The concentrations and spatial distributions of eight heavy metals in surface sediments and sediment core samples from a shallow lake in China were investigated to evaluate the extent of the contamination and potential ecological risks. The results showed that the heavy metal concentrations were higher in the northern and southwestern lake zones than those in the other lake zones, with lower levels of As, Hg, Zn, Cu, Pb, Cr, and Ni primarily observed in the central and eastern lake regions and Cd primarily confined to areas surrounding the lake. The concentrations of the eight heavy metals in the sediment profiles tended to decrease with increasing sediment depth. The contents of Ni, Cu, Zn, Pb, and Cd in the surface sediment were approximately 1.23-18.41-fold higher than their background values (BVs), whereas the contents of Cr, As, and Hg were nearly identical to their BVs. The calculated pollution load index (PLI) suggested that the surface sediments of this lake were heavily polluted by these heavy metals and indicated that Cd was a predominant contamination factor. The comprehensive potential ecological risk index (PERI) in the surface sediments ranged from 99.2 to 2882.1, with an average of 606.1. Cd contributed 78.7 % to the PERI, and Hg contributed 8.4 %. Multivariate statistical analyses revealed that the surface sediment pollution with heavy metals mainly originated from industrial wastewater discharged by rivers located in the western and northwestern portion of the lake.

  2. Role of storms and forest practices in sedimentation of an Oregon Coast Range lake

    Science.gov (United States)

    Richardson, K.; Hatten, J. A.; Wheatcroft, R. A.; Guerrero, F. J.

    2014-12-01

    The design of better management practices in forested watersheds to face climate change and the associated increase in the frequency of extreme events requires a better understanding of watershed responses to extreme events in the past and also under management regimes. One of the most sensitive watershed processes affected is sediment yield. Lake sediments record events which occur in a watershed and provide an opportunity to examine the interaction of storms and forest management practices in the layers of the stratigraphy. We hypothesize that timber harvesting and road building since the 1900s has resulted in increases in sedimentation; however, the passage of the Oregon Forest Practices Act (OFPA) in 1972 has led to a decrease in sedimentation. Sediment cores were taken at Loon Lake in the Oregon Coast Range. The 32-m deep lake captures sediment from a catchment highly impacted by recent land use and episodic Pacific storms. We can use sedimentological tools to measure changes in sediment production as motivated by extreme floods before settlement, during a major timber harvesting period, and after installation of forestry Best Management Practices. Quantification of changes in particle size and elemental composition (C, N, C/N) throughout the cores can elucidate changes in watershed response to extreme events, as can changes in layer thickness. Age control in the cores is being established by Cesium-137 and radiocarbon dating. Given the instrumental meteorological data and decadal climate reconstructions, we will disentangle climate driven signals from changes in land use practices. The sediment shows distinct laminations and varying thickness of layers throughout the cores. Background deposition is composed of thin layers (events to determine if the OFPA is having an effect on reducing sedimentation rates as a result of extreme magnitude storm events.

  3. Phosphorus fractions and its potential release in the sediments of Koycegiz Lake, Turkey

    Directory of Open Access Journals (Sweden)

    Yalçın Şahin

    2012-12-01

    Full Text Available This study was conducted to find out the seasonal and spatial patterns of the phosphorus in the littoral sediment and its potential release into the Koycegiz Lake, south west Turkey, between November 2011 and March 2012 at two months intervals. The scanning electron microscopy was used for elemental compositions of the sediment. The amounts and forms of phosphorus (P in surface sediments of Koycegiz Lake were examined using a not sequential chemical extraction procedure. Four fractions of sedimentary P, including organic bound phosphorus fraction (Org≈P, calcium bound phosphorus fraction (Ca≈P, iron+aluminium bound phosphorus fraction (Fe+Al≈P and carbonate bound phosphorus fraction (CO3≈P were separately quantified. The results indicated that the contents of different phosphorus fractions in the sediments varied greatly. The proportion of phosphorus fractions was estimated as Org≈P (90.20 %, this fraction was followed by Ca≈P (9.06 %, Fe+Al≈P (0.47 % and CO3≈P (0.27 % in this study. The level of phosphorus release from the sediment to the lake is calculated as low. The sediment phosphorus release fluctuated between -6.647–75.883 μg/m2.d-1 and the total phosphorus (TP concentrations of the sediment samples were changed between 980.39 μg/gDW (Dry Weight - 1990.81 μg/gDW. The results show that it can be evaluation as eutrophic for Koycegiz Lake.

  4. Patterns and controls of mercury accumulation in sediments from three thermokarst lakes on the Arctic Coastal Plain of Alaska

    Science.gov (United States)

    Burke, Samantha M.; Zimmerman, Christian E.; Branfireun, Brian A.; Koch, Joshua C.; Swanson, Heidi K.

    2018-01-01

    The biogeochemical cycle of mercury will be influenced by climate change, particularly at higher latitudes. Investigations of historical mercury accumulation in lake sediments inform future predictions as to how climate change might affect mercury biogeochemistry; however, in regions with a paucity of data, such as the thermokarst-rich Arctic Coastal Plain of Alaska (ACP), the trajectory of mercury accumulation in lake sediments is particularly uncertain. Sediment cores from three thermokarst lakes on the ACP were analyzed to understand changes in, and drivers of, Hg accumulation over the past ~ 100 years. Mercury accumulation in two of the three lakes was variable and high over the past century (91.96 and 78.6 µg/m2/year), and largely controlled by sedimentation rate. Mercury accumulation in the third lake was lower (14.2 µg/m2/year), more temporally uniform, and was more strongly related to sediment Hg concentration than sedimentation rate. Sediment mercury concentrations were quantitatively related to measures of sediment composition and VRS-inferred chlorophyll a, and sedimentation rates were related to various catchment characteristics. These results were compared to data from 37 previously studied Arctic and Alaskan lakes. Results from the meta-analysis indicate that thermokarst lakes have significantly higher and more variable Hg accumulation rates than non-thermokarst lakes, suggesting that certain properties (e.g., thermal erosion, thaw slumping, low hydraulic conductivity) likely make lakes prone to high and variable Hg accumulation rates. Differences and high variability in Hg accumulation among high latitude lakes highlight the complexity of predicting future climate-related change impacts on mercury cycling in these environments.

  5. Geochronologic study of sediments deposition of two lakes from the Rio Negro basin, Amazonas State, Brazil

    International Nuclear Information System (INIS)

    Gomes, Ana Carla F.; Mozeto, Antonio A.; Cazotti, Raul I.; Nascimento Filho, Virgilio F.; Taddei, Maria Helena

    2000-01-01

    Since 1963 the radionuclide 210 Pb became an important tool for dating (geochronology) recent sediments (up to 120 years). In this work the sedimentary geochronology of two lakes from the Negro River Basin was determined, using different radiochemical separation methods for 210 Pb and 226 Ra. (author)

  6. Patterns of extracellular enzyme activities in littoral sediments of Lake Gooimeer, The Netherlands

    NARCIS (Netherlands)

    Boschker, H.T.S.; Cappenberg, T.E.

    1998-01-01

    The seasonal variation in enzymatic activities against protein and several polysaccharides together with esterase as a measure of general hydrolytic activity was studied in a transect of sediments through the littoral zone of Lake Gooimeer, The Netherlands. Absolute activities showed a linear

  7. Application of PAH concentration profiles in lake sediments as indicators for smelting activity.

    Science.gov (United States)

    Warner, Wiebke; Ruppert, Hans; Licha, Tobias

    2016-09-01

    The ability of lake sediment cores to store long-term anthropogenic pollution establishes them as natural archives. In this study, we focus on the influence of copper shale mining and smelting in the Mansfeld area of Germany, using the depth profiles of two sediment cores from Lake Süßer See. The sediment cores provide a detailed chronological deposition history of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the studied area. Theisen sludge, a fine-grained residue from copper shale smelting, reaches the lake via deflation by wind or through riverine input; it is assumed to be the main source of pollution. To achieve the comparability of absolute contaminant concentrations, we calculated the influx of contaminants based on the sedimentation rate. Compared to the natural background concentrations, PAHs are significantly more enriched than heavy metals. They are therefore more sensitive and selective for source apportionment. We suggest two diagnostic ratios of PAHs to distinguish between Theisen sludge and its leachate: the ratio fluoranthene to pyrene ~2 and the ratio of PAH with logKOW5.7 converging to an even lower value than 2.3 (the characteristic of Theisen sludge) to identify the particulate input in lake environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Biogeochemical Cycling of Nutrients and Trace Metals in the Sediment of Haringvliet Lake: Response to Salinization

    NARCIS (Netherlands)

    Canavan, R.W.

    2006-01-01

    This thesis examines sediment redox processes associated with organic matter degradation and their impact on the cycling of nutrients (N, P) and trace metals (Cd, Co, Ni, Pb, Zn). Our study site, Haringvliet Lake, is located in the Rhine-Meuse River Delta in the southwest of The Netherlands. This

  9. Nitrogen removal by denitrification in the sediments of a shallow lake

    NARCIS (Netherlands)

    Luijn, van F.

    1997-01-01

    Most surface waters in the Netherlands are highly eutrophicated due to high loadings with the nutrients nitrogen (N) and phosphorus (P). To improve the water quality of lakes often the phosphorus loading is reduced. Due to phosphorus release from the sediments the success of the recovery of

  10. Silver and lead in high-altitude lake sediments: Proxies for climate changes and human activities

    International Nuclear Information System (INIS)

    Garçon, Marion; Chauvel, Catherine; Chapron, Emmanuel; Faïn, Xavier; Lin, Mingfang; Campillo, Sylvain; Bureau, Sarah; Desmet, Marc; Bailly-Maître, Marie-Christine; Charlet, Laurent

    2012-01-01

    High-altitude lake sediments are often used as archives for environmental changes and their chemical and isotopic compositions provide significant constraints on natural and anthropogenic long-term changes that have occurred in their catchment area. Here, trace-element concentrations and Pb isotopes are presented for two sedimentary cores from Lake Blanc Huez in the French Alps, to trace the impact of climate changes and human activities over the Holocene. Lead and Ag contents are very high and clearly dominated by input from a Pb–Ag vein located a few meters from the lakeshore, a vein that also buffers the Pb isotopes. Mining of this vein in medieval times is recorded in the corresponding lake sediments with high Ag content coupled with high Pb/U ratio. These chemical characteristics can be used to constrain the major Holocene climate changes. Significant advances of glaciers next to the lake produced sediments with Ag and Pb concentration peaks and high Pb/U ratios due to accelerated erosion of the Pb–Ag vein, similar to the effects of the medieval mining. In contrast, reduced glacier activity led to the formation of organic-rich sediments with high U and As contents and low Pb/U ratios. More generally, the observed combination of chemical changes could be used elsewhere to decipher environmental changes over long periods of time.

  11. Distribution and sources of n-alkanes in surface sediments of Taihu Lake, China

    Directory of Open Access Journals (Sweden)

    Yu Yunlong

    2016-03-01

    Full Text Available The last study on n-alkanes in surface sediments of Taihu Lake was in 2000, only 13 surface sediment samples were analysed, in order to have a comprehensive and up-to-date understanding of n-alkanes in the surface sediments of Taihu Lake, 41 surface sediment samples were analyzed by GC-MS. C10 to C37 were detected, the total concentrations of n-alkanes ranged from 2109 ng g−1 to 9096 ng g−1 (dry weight. There was strong odd carbon predominance in long chain n-alkanes and even carbon predominance in short chain n-alkanes. When this finding was combined with the analysis results of wax n-alkanes (WaxCn, carbon preference index (CPI, unresolved complex mixture (UCM, hopanes and steranes, it was considered that the long chain n-alkanes were mainly from terrigenous higher plants, and that the short chain n-alkanes mainly originated from bacteria and algae in the lake, compared with previous studies, there were no obvious anthropogenic petrogenic inputs. Terrestrial and aquatic hydrocarbons ratio (TAR and C21−/C25+ indicated that terrigenous input was higher than aquatic sources and the nearshore n-alkanes were mainly from land-derived sources. Moreover, the distribution of short chain n-alkanes presented a relatively uniform pattern, while the long chain n-alkanes presented a trend that concentrations dropped from nearshore places to the middle of lake.

  12. The distribution and abundance of gamma emitting radionuclides in Lake Ontario sediments

    International Nuclear Information System (INIS)

    McKinley, R.S.

    1985-03-01

    The distribution of gamma emitting radionuclides in Lake Ontario sediments was investigated. Samples were collected using a systematic design in the vicinity of Pickering and Darlington, and supplemented by lakewide offshore samples. Naturally occurring 40 K was the predominant source of gamma activity. 60 Co was the only potentially CANDU released radionuclide which showed a distributional association with the Pickering 'A' NGS discharge

  13. Reconstruction of historical atmospheric Pb using Dutch urban lake sediments: A Pb isotope study

    NARCIS (Netherlands)

    Walraven, N.; van Os, B.J.H.; Klaver, G.Th.; Middelburg, J.J.; Davies, G.R.

    2014-01-01

    Lake sediments provide a record of atmospheric Pb deposition and changes in Pb isotope composition. To our knowledge, such an approach has not previously been performed in The Netherlands or linked to national air monitoring data. Results are presented for Pb content and isotope composition of 137Cs

  14. Sediment Budget on the Indiana Shore at Burns Harbor, Lake Michigan

    Science.gov (United States)

    2015-05-15

    Zone 16N, North American Datum 1983, units in meters. Features specifically related to an elevation (for example, +2 ft low water datum ( LWD ...redrawn and imported into RMAP software. Original English units for distance and elevation with respect to LWD IGLD 1955 retained. (1 ft = 0.3048 m...2 ft LWD IGLD1955. Photographs from other dates are in Morang et al. (2012). Fig. 6. October 2011. The exposed fillet extended to about half the

  15. Chemical indicators of anthropogenic impacts in sediments of the pristine karst lakes.

    Science.gov (United States)

    Mikac, I; Fiket, Z; Terzić, S; Barešić, J; Mikac, N; Ahel, M

    2011-08-01

    The anthropogenic impact on the pristine karst lakes was investigated using combination of specific parameters, including multielemental analysis of major inorganic constituents (Al, K, Fe) and trace metals (Li, Ag, Cd, Sn, Pb, Bi, Cr, Co, Ni, Cu, Zn and Sb), polycyclic aromatic hydrocarbons (PAHs) and anionic surfactants of linear alkylbenzene sulfonate (LAS) type. The study was performed in the Plitvice Lakes National Park, situated in a sparsely populated area of the northwestern Dinarides, central Croatia. Dated cores of recent sediments from the two biggest lakes, Lake Prosce and Lake Kozjak, were analysed for the selected contaminants using highly specific methods, involving inductively coupled plasma mass spectrometry (ICP/MS), gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). The concentration of inorganic constituents reflected primarily the geological background of the area as well as geomorphological and geochemical characteristics of the Plitvice Lakes. Due to the higher terrigenous input, the concentration of all elements was significantly higher in the Lake Prosce. The concentration of toxic metals was relatively low in both lakes, except for Cd (>1 mg kg(-1)) and Pb (up to 40 mg kg(-1)). The vertical profiles of these metals suggested that elevated concentrations of Cd were of natural origin, derived from the erosion of the Jurassic dolomite bedrock, while Pb was predominately of recent anthropogenic origin. A similar distribution pattern, suggesting the same prevailing mechanism of input, was observed for pyrolytic PAHs. The characteristic diagnostic PAH ratios revealed that higher PAHs prevailingly originated from the combustion of biomass and fossil fuels. LAS, which represent highly specific indicators of untreated wastewaters, were found in rather high concentrations in the recent sediment layers (up to 4.7 mg kg(-1)), suggesting that contaminated household and hotel wastewaters reach the

  16. Long livestock farming history and human landscape shaping revealed by lake sediment DNA.

    Science.gov (United States)

    Giguet-Covex, Charline; Pansu, Johan; Arnaud, Fabien; Rey, Pierre-Jérôme; Griggo, Christophe; Gielly, Ludovic; Domaizon, Isabelle; Coissac, Eric; David, Fernand; Choler, Philippe; Poulenard, Jérôme; Taberlet, Pierre

    2014-01-01

    The reconstruction of human-driven, Earth-shaping dynamics is important for understanding past human/environment interactions and for helping human societies that currently face global changes. However, it is often challenging to distinguish the effects of the climate from human activities on environmental changes. Here we evaluate an approach based on DNA metabarcoding used on lake sediments to provide the first high-resolution reconstruction of plant cover and livestock farming history since the Neolithic Period. By comparing these data with a previous reconstruction of erosive event frequency, we show that the most intense erosion period was caused by deforestation and overgrazing by sheep and cowherds during the Late Iron Age and Roman Period. Tracking plants and domestic mammals using lake sediment DNA (lake sedDNA) is a new, promising method for tracing past human practices, and it provides a new outlook of the effects of anthropogenic factors on landscape-scale changes.

  17. Sediment core fossils in ancient Lake Ohrid: testing for faunal change since the Last Interglacial

    Directory of Open Access Journals (Sweden)

    C. Albrecht

    2010-11-01

    Full Text Available Ancient Lake Ohrid is probably of early Pleistocene or Pliocene origin and amongst the few lakes in the world harbouring an outstanding degree of endemic biodiversity. Although there is a long history of evolutionary research in Lake Ohrid, particularly on molluscs, a mollusc fossil record has been missing up to date. For the first time, gastropod and bivalve fossils are reported from the basal, calcareous part of a 2.6 m long sediment succession (core Co1200 from the north-eastern part of Lake Ohrid. Electron spin resonance (ESR dating of mollusc shells from the same stratigraphic level yielded an age of 130 ± 28 ka. Lithofacies III sediments, i.e. a stratigraphic subdivision comprising the basal succession of core Co1200 between 181.5–263 cm, appeared solid, greyish-white, and consisted almost entirely of silt-sized endogenic calcite (CaCO3>70% and intact and broken mollusc shells. Here we compare the faunal composition of the thanatocoenosis with recent mollusc associations in Lake Ohrid. A total of 13 mollusc species (9 gastropod and 4 bivalve species could be identified within Lithofacies III sediments. The value of sediment core fossils for reconstructing palaeoenvironmental settings was evaluated and the agreement between sediment and palaeontological proxies was tested.

    The study also aims at investigating major faunal changes since the Last Interglacial and searching for signs of extinction events.

    The combined findings of the ecological study and the sediment characteristics suggest deposition in a shallow water environment during the Last Interglacial. The fossil fauna exclusively included species also found in the present fauna, i.e. no extinction events are evident for this site since the Last Interglacial. The thanatocoenosis showed the highest similarity with recent Intermediate Layer (5–25 m water depth mollusc assemblages. The demonstrated existence of a mollusc fossil record in Lake Ohrid

  18. Holocene glacier fluctuations inferred from lacustrine sediment, Emerald Lake, Kenai Peninsula, Alaska

    Science.gov (United States)

    LaBrecque, Taylor S.; Kaufman, Darrell S.

    2016-01-01

    Physical and biological characteristics of lacustrine sediment from Emerald Lake were used to reconstruct the Holocene glacier history of Grewingk Glacier, southern Alaska. Emerald Lake is an ice-marginal threshold lake, receiving glaciofluvial sediment when Grewingk Glacier overtops the topographic divide that separates it from the lake. Sub-bottom acoustical profiles were used to locate core sites to maximize both the length and resolution of the sedimentary sequence recovered in the 4-m-long cores. The age model for the composite sequence is based on 13 14C ages and a 210Pb profile. A sharp transition from the basal inorganic mud to organic-rich mud at 11.4 ± 0.2 ka marks the initial retreat of Grewingk Glacier below the divide of Emerald Lake. The overlaying organic-rich mud is interrupted by stony mud that records a re-advance between 10.7 ± 0.2 and 9.8 ± 0.2 ka. The glacier did not spill meltwater into the lake again until the Little Ice Age, consistent with previously documented Little Ice Ages advances on the Kenai Peninsula. The retreat of Grewingk Glacier at 11.4 ka took place as temperature increased following the Younger Dryas, and the subsequent re-advance corresponds with a climate reversal beginning around 11 ka across southern Alaska.

  19. Evidence for mild sediment Pb contamination affecting leaf-litter decomposition in a lake.

    Science.gov (United States)

    Oguma, Andrew Y; Klerks, Paul L

    2015-08-01

    Much work has focused on the effects of metal-contaminated sediment on benthic community structure, but effects on ecosystem functions have received far less attention. Decomposition has been widely used as an integrating metric of ecosystem function in lotic systems, but not for lentic ones. We assessed the relationship between low-level sediment lead (Pb) contamination and leaf-litter decomposition in a lentic system. We measured 30-day weight loss in 30 litter-bags that were deployed along a Pb-contamination gradient in a cypress-forested lake. At each deployment site we also quantified macrobenthos abundance, dissolved oxygen, water depth, sediment organic content, sediment silt/clay content, and both total sediment and porewater concentrations of Cd, Cu, Ni, Pb and Zn. Principal components (PC) analysis revealed a negative relationship between Pb concentration and benthic macroinvertebrate abundance, and this covariation dominated the first PC axis (PC1). Subsequent correlation analyses revealed a negative relationship between PC1 and percent leaf-litter loss. Our results indicate that leaf-litter decomposition was related to sediment Pb and benthic macroinvertebrate abundance. They also showed that ecosystem function may be affected even where sediment Pb concentrations are mostly below threshold-effects sediment quality guidelines--a finding with potential implications for sediment risk assessment. Additionally, the litter-bag technique used in this study showed promise as a tool in risk assessments of metal-contaminated sediments in lentic systems.

  20. Heavy metal speciation and their accumulation in sediments of Lake ...

    African Journals Online (AJOL)

    UFUOMA

    African Journal of Environmental Science and Technology Vol. 5(4), pp. 280-298, April ..... present study gave higher values due to the effect of increasing ...... on The Heavy Metal. Pollution of Guanabara Bay Sediments and Evaluation of The.

  1. Uranium isotopes in waters and bottom sediments of rivers and lakes in Poland

    International Nuclear Information System (INIS)

    Pietrzak-Flis, Z.; Kaminska, I.; Chrzanowski, E.

    2004-01-01

    Activity concentrations of 238 U, 234 U and 235 U were determined in waters and bottom sediments in two main rivers in Poland (the Vistula and Odra rivers) with their tributaries, in four coastal rivers and six lakes. Concentration of 238 U and 233 U were compared with the concentrations of 226 Ra determined in another study. As compared with concentrations in coastal rivers and in lakes, enhanced concentrations of the radionuclides were observed in water and bottom sediments in the upper and middle courses of Vistula river, whereas in the Odra river the enhanced concentrations were present only in the bottom sediments. The enhanced concentrations in the Vistula river result from the discharge of coal mine waters from the Upper Silesian Coal Basin, and they indicate that the discharge was continued. The enhanced concentration in Odra river observed only in bottom sediments indicate that the discharge occurred in the past. The 234 U/ 238 U ratio for the bottom sediments was close to unity, indicating that these isotopes were close to equilibrium, whereas for water the average ratio was form 1.2 for lakes to 1.5 for the Vistula river, demonstrating the lack of equilibrium. (author)

  2. Metal pollution assessment in the surface sediment of Lake Nasser, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed E. Goher

    2014-01-01

    Full Text Available Eight heavy metals were measured seasonally in the sediment of Lake Nasser during 2013. 27 sites were chosen through 9 sectors across the main channel of the lake from Abu-Simbel to Aswan High Dam to assess the levels of the selected metals. The abundance of these metals was in the order of Fe > Mn > Zn > Cr > Ni > Cu > Pb > Cd, with mean concentrations of 12.41 mg/g, 279.56, 35.38, 30.79, 27.56, 21.78, 11.21 and 0.183 μg/g, respectively. Heavy metals are positively correlated with fine particles (mud fractions and organic matter accumulation. The results showed perspicuous spatial high significant differences (P < 0.01 for all the measured metals. Fe, Cr, Ni, Pb and Cd exhibited temporally high significant differences (P < 0.01 before and after the flood period. Four Pollution Indices were used for the environmental assessment of Lake Nasser sediment. The indices included three single indices, Enrichment Factor (EF, Index of Geo-accumulation (Igeo and Contamination Factor (CF. While the fourth, Pollution Load Index (PLI was an integrated index. The pollution indexes confirmed that the Lake Nasser sediment was not contaminated with these elements. Sediments of Lake Nasser may be represented as a reference for the pre-industrial background of River Nile Sediments downstream Aswan High Dam.

  3. Impact of methane flow through deformable lake sediments on atmospheric release

    Science.gov (United States)

    Scandella, B.; Juanes, R.

    2010-12-01

    Methane is a potent greenhouse gas that is generated geothermally and biologically in lake and ocean sediments. Free gas bubbles may escape oxidative traps and contribute more to the atmospheric source than dissolved methane, but the details of the methane release depend on the interactions between the multiple fluid phases and the deformable porous medium. We present a model and supporting laboratory experiments of methane release through “breathing” dynamic flow conduits that open in response to drops in the hydrostatic load on lake sediments, which has been validated against a high-resolution record of free gas flux and hydrostatic pressure in Upper Mystic Lake, MA. In contrast to previous linear elastic fracture mechanics analysis of gassy sediments, the evolution of gas transport in a deformable compliant sediment is presented within the framework of multiphase poroplasticity. Experiments address how strongly the mode and rate of gas flow, captured by our model, impacts the size of bubbles released into the water column. A bubble's size in turn determines how efficiently it transports methane to the atmosphere, and integrating this effect will be critical to improving estimates of the atmospheric methane source from lakes. Cross-sectional schematic of lake sediments showing two venting sites: one open at left and one closed at right. The vertical release of gas bubbles (red) at the open venting site creates a local pressure drop, which drives both bubble formation from the methane-rich pore water (higher concentrations shaded darker red) and lateral advection of dissolved methane (purple arrows). Even as bubbles in the open site escape, those at the closed site remain trapped.

  4. Patterns and sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in surficial sediments of Lakes Erie and Ontario

    International Nuclear Information System (INIS)

    Shen Li; Gewurtz, Sarah B.; Reiner, Eric J.; MacPherson, Karen A.; Kolic, Terry M.; Helm, Paul A.; Brindle, Ian D.; Marvin, Chris H.

    2008-01-01

    This study determines spatial trends and congener patterns of 2378-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in surficial sediments of Lakes Erie and Ontario. Sediments are enriched in 2378-PCDFs in Lake Ontario, and the PCDD/F concentrations increased from shallow near-shore sediments towards deep-water depositional zone sediments. In Lake Erie, sediments were dominated by octachlorodibenzo-p-dioxin, and the highest PCDD/F concentrations were observed in the western basin and the southern shoreline of the central basin with a decrease towards the eastern basin and the northern shoreline of the central basin. Principal components analysis revealed that chemical manufacture and disposal of chemical waste along the Niagara River has been a major PCDD/F source to Lake Ontario; while PCDD/Fs in Lake Erie are from multiple sources including industrial sources along the Detroit River, major tributaries along the southern shoreline of the lake, and atmospherically-derived material from the upper lakes and connecting channels. - Lake-wide 2378-PCDD/F congener patterns are first reported in L. Erie and L. Ontario sediments

  5. Recent changes in mercury deposition and primary productivity inferred from sediments of lakes from the Hudson Bay Lowlands, Ontario, Canada

    International Nuclear Information System (INIS)

    Brazeau, Michelle L.; Poulain, Alexandre J.; Paterson, Andrew M.; Keller, Wendel; Sanei, Hamed; Blais, Jules M.

    2013-01-01

    Spatial and temporal changes in mercury (Hg) concentrations and organic carbon in lake sediments were examined from the Hudson Bay Lowlands to investigate whether Hg deposition to sediments is related to indicators of autochthonous production. Total organic carbon, “S2” carbon (mainly algal-derived OC), C:N and ∂ 13 C indicators suggest an increase in autochthonous productivity in recent decades. Up-core profiles of S2 concentrations and fluxes were significantly correlated with Hg suggesting that varying algal matter scavenging of Hg from the water column may play an important role in the temporal profiles of Hg throughout the sediment cores. Absence of significant relationship between total Hg and methyl Hg (MeHg) in surficial sediments suggested that inorganic Hg supply does not limit MeHg production. MeHg and OC were highly correlated across lakes in surface and deep sediment layers, indicating that sediment organic matter content explains part of the spatial variation in MeHg concentrations between lakes. - Highlights: ► Hg concentrations in sediment cores correlate with autochthonous organic production. ► Inorganic Hg supply in sediment does not limit MeHg production. ► Sediment methylmercury concentration is highly correlated with organic C content. - Increased mercury concentrations in lake sediment cores coincide with evidence of increased autochthonous production in lakes of the Hudson Bay Lowlands, Canada.

  6. Effects of experimental acidification on mobilisation of metals from sediments of limed and non-limed lakes

    International Nuclear Information System (INIS)

    Waellstedt, Teresia; Borg, H