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Sample records for sediments central bay

  1. Sediment depositional environment in some bays in Central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rajamanickam, G.V.; Gujar, A.R.

    negatively and Ratnagiri Bay positively skewed. Kalbadevi sediments show high kurtosis values while those of Mirya Bay show medium and Ratnagiri Bay low values. Bivariant plots between various textural parameters predict mixed environments, viz. for Kalbadevi...

  2. Hydrocarbons in the Bay of Bengal and Central Indian Basin bottom sediments: Indicators of geochemical processes in the lithosphere

    Digital Repository Service at National Institute of Oceanography (India)

    Chernova, T.G.; Paropkari, A.L.; Pikovskii, Yu.I.; Alekseeva, T.A.

    A study on the bulk distributions and molecular structures of n-alkanes and polycyclic aromatic hydrocarbons (PAH) in organic matter of the sediments from the Bay of Bengal and the Eastern and Central Indian Basins was underdaken. The former two...

  3. Anthropogenic influence on recent bathymetric change in west-central San Francisco Bay

    Science.gov (United States)

    Barnard, Patrick L.; Kvitek, Rikk G.

    2010-01-01

    Two multibeam sonar surveys of west-central San Francisco Bay, California, were conducted in 1997 and 2008. Bathymetric change analysis between the two surveys indicates a loss of 14.1 million cubic meters (-3.1 cm/yr-1) of sediment during this time period, representing an approximately three-fold acceleration of the rate that was observed from prior depth change analysis from 1947 to 1979 for all of Central Bay, using more spatially coarse National Ocean Service (NOS) soundings. The portions of the overlapping survey areas between 1997 and 2008 designated as aggregate mining lease sites lost sediment at five times the rate of the remainder of west-central San Francisco Bay. Despite covering only 28% of the analysis area, volume change within leasing areas accounted for 9.2 million cubic meters of sediment loss, while the rest of the area lost 4.9 million cubic meters of sediment. The uncertainty of this recent analysis is more tightly constrained due to more stringent controls on vertical and horizontal position via tightly coupled, inertially aided differential Global Positioning Systems (GPS) solutions for survey vessel trajectory that virtually eliminate inaccuracies from traditional tide modeling and vessel motion artifacts. Further, quantification of systematic depth measurement error can now be calculated through comparison of static surfaces (e.g., bedrock) between surveys using seafloor habitat maps based on acoustic backscatter measurements and ground-truthing with grab samples and underwater video. Sediment loss in the entire San Francisco Bay Coastal System during the last half-century,as estimated from a series of bathymetric change studies, is 240 million cubic meters, and most of this is believed to be coarse sediment (i.e., sand and gravel) from Central Bay and the San Francisco Bar, which is likely to limit the sand supply to adjacent, open-coast beaches. This hypothesis is supported by a calibrated numerical model in a related study that indicates

  4. Pb’s high sedimentation inside the bay mouth of Jiaozhou Bay

    Science.gov (United States)

    Yang, Dongfang; Miao, Zhenqing; Huang, Xinmin; Wei, Linzhen; Feng, Ming

    2017-12-01

    Sedimentation is one of the key environmental behaviors of pollutants in the ocean. This paper analyzed the seasonal and temporal variations of Pb’s sedimentation process in Jiaozhou Bay in 1987. Results showed that Pb contents in bottom waters in Jiaozhou Bay in May, July and November 1987 were 1.87-2.60 μg L-1, 15.11-19.68 μg L-1 and 11.08-15.18 μg L-1, and the pollution levels of Pb in May, July and November 1987 were slight, heavy and heavy, respectively. In May 1987, there was low sedimentation process in waters in the outside of the bay mouth, yet were high sedimentation process in waters in the middle and inside of the bay mouth. In July and November 1987, there was low sedimentation process in waters in the outside of the bay mouth, yet were high sedimentation process in waters in the inside of the bay mouth. The seasonal-temporal variation of sedimentation processes of Pb were determined by the variations of sources input and the vertical water’s effect.

  5. Radionuclides in sediments from Port Phillip Bay, Australia

    International Nuclear Information System (INIS)

    Smith, J.D.; Tinker, R.A.; Towler, P.H.

    1998-01-01

    Full text: Sediment cores were collected from two sites in Port Phillip Bay, Australia, in 1994 and 1995. The concentration of 210 Pb and parameters including water content were measured. The sites chosen were near the centre of the bay where fine sediment accumulates, and towards the northern end of the bay closer to the mouth of the Yarra River. The mid-bay sediment had a high water content (about 1.8 g water per g dry sediment) and a supported 210 Pb activity of about 22 mBq per g of dry sediment. The sediments from further north in the bay were more consolidated, with a lower water content (about 0.6 g water per g dry sediment), and had a supported 210 Pb activity of about 6 mBq per g of dry sediment. Unsupported 210 Pb occurred to depths of about 10 cm in the mid-bay sediment and about 20 cm in sediment from further north in the bay. Models incorporating the water and 210 Pb contents of the sediments were used to calculate possible rates of sediment accumulation and mixing. The distribution of other radionuclides was used as an aid in understanding the sediment behaviour in Port Phillip Bay

  6. Distribution and behavior of major and trace elements in Tokyo Bay, Mutsu Bay and Funka Bay marine sediments

    International Nuclear Information System (INIS)

    Honda, Teruyuki; Kimura, Ken-ichiro

    2003-01-01

    Fourteen major and trace elements in marine sediment core samples collected from the coasts along eastern Japan, i.e. Tokyo Bay (II) (the recess), Tokyo Bay (IV) (the mouth), Mutsu Bay and Funka Bay and the Northwest Pacific basin as a comparative subject were determined by the instrumental neutron activation analysis (INAA). The sedimentation rates and sedimentary ages were calculated for the coastal sediment cores by the 210 Pb method. The results obtained in this study are summarized as follows: (1) Lanthanoid abundance patterns suggested that the major origin of the sediments was terrigenous material. La*/Lu* and Ce*/La* ratios revealed that the sediments from Tokyo Bay (II) and Mutsu Bay more directly reflected the contribution from river than those of other regions. In addition, the Th/Sc ratio indicated that the coastal sediments mainly originated in the materials from the volcanic island-arcs, Japanese islands, whereas those from the Northwest Pacific mainly from the continent. (2) The correlation between the Ce/U and Th/U ratios with high correlation coefficients of 0.920 to 0.991 indicated that all the sediments from Tokyo Bay (II) and Funka Bay were in reducing conditions while at least the upper sediments from Tokyo Bay (IV) and Mutsu Bay were in oxidizing conditions. (3) It became quite obvious that the sedimentation mechanism and the sedimentation environment at Tokyo Bay (II) was different from those at Tokyo Bay (IV), since the sedimentation rate at Tokyo Bay (II) was approximately twice as large as that at Tokyo Bay (IV). The sedimentary age of the 5th layer (8∼10 cm in depth) from Funka Bay was calculated at approximately 1940∼50, which agreed with the time, 1943∼45 when Showa-shinzan was formed by the eruption of the Usu volcano. (author)

  7. Development, evaluation, and application of sediment quality targets for assessing and managing contaminated sediments in Tampa Bay, Florida

    Science.gov (United States)

    MacDonald, D.D.; Carr, R.S.; Eckenrod, D.; Greening, H.; Grabe, S.; Ingersoll, C.G.; Janicki, S.; Janicki, T.; Lindskoog, R.A.; Long, E.R.; Pribble, R.; Sloane, G.; Smorong, D.E.

    2004-01-01

    Tampa Bay is a large, urban estuary that is located in west central Florida. Although water quality conditions represent an important concern in this estuary, information from numerous sources indicates that sediment contamination also has the potential to adversely affect aquatic organisms, aquatic-dependent wildlife, and human health. As such, protecting relatively uncontaminated areas of the bay from contamination and reducing the amount of toxic chemicals in contaminated sediments have been identified as high-priority sediment management objectives for Tampa Bay. To address concerns related to sediment contamination in the bay, an ecosystem-based framework for assessing and managing sediment quality conditions was developed that included identification of sediment quality issues and concerns, development of ecosystem goals and objectives, selection of ecosystem health indicators, establishment of metrics and targets for key indicators, and incorporation of key indicators, metrics, and targets into watershed management plans and decision-making processes. This paper describes the process that was used to select and evaluate numerical sediment quality targets (SQTs) for assessing and managing contaminated sediments. These SQTs included measures of sediment chemistry, whole-sediment and pore-water toxicity, and benthic invertebrate community structure. In addition, the paper describes how the SQTs were used to develop site-specific concentration-response models that describe how the frequency of adverse biological effects changes with increasing concentrations of chemicals of potential concern. Finally, a key application of the SQTs for defining sediment management areas is discussed.

  8. Suspended sediment and sediment-associated contaminants in San Francisco Bay

    Science.gov (United States)

    Schoellhamer, D.H.; Mumley, T.E.; Leatherbarrow, J.E.

    2007-01-01

    Water-quality managers desire information on the temporal and spatial variability of contaminant concentrations and the magnitudes of watershed and bed-sediment loads in San Francisco Bay. To help provide this information, the Regional Monitoring Program for Trace Substances in the San Francisco Estuary (RMP) takes advantage of the association of many contaminants with sediment particles by continuously measuring suspended-sediment concentration (SSC), which is an accurate, less costly, and more easily measured surrogate for several trace metals and organic contaminants. Continuous time series of SSC are collected at several sites in the Bay. Although semidiurnal and diurnal tidal fluctuations are present, most of the variability of SSC occurs at fortnightly, monthly, and semiannual tidal time scales. A seasonal cycle of sediment inflow, wind-wave resuspension, and winnowing of fine sediment also is observed. SSC and, thus, sediment-associated contaminants tend to be greater in shallower water, at the landward ends of the Bay, and in several localized estuarine turbidity maxima. Although understanding of sediment transport has improved in the first 10 years of the RMP, determining a simple mass budget of sediment or associated contaminants is confounded by uncertainties regarding sediment flux at boundaries, change in bed-sediment storage, and appropriate modeling techniques. Nevertheless, management of sediment-associated contaminants has improved greatly. Better understanding of sediment and sediment-associated contaminants in the Bay is of great interest to evaluate the value of control actions taken and the need for additional controls. ?? 2007 Elsevier Inc. All rights reserved.

  9. Seasonal variation of iron speciation in a pearl-raising bay sediment by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Kuno, Akihito; Matsuo, Motoyuki; Chiba, Satoshi; Yamagata, Yoichi

    2008-01-01

    Ago Bay in Mie Prefecture, central Japan, is world-famous for the site of Mikimoto pearl culture, but recently the production of pearls has considerably declined. Environmental deterioration of the bay is suspected of having caused the decline. The periodic investigation into iron speciation of the bay sediment by 57 Fe Moessbauer spectroscopy revealed its high pyrite (FeS 2 ) content from the surface to the 20-cm depth. The pyrite in the surface sediment decreased only in spring, three months after the dissolved oxygen in the bottom water was at maximum. Such oxygen-consuming material as pyrite accumulated through long-term biotic activity is a most-likely explanation for the prolonged environmental deterioration of the bay, which appears in the high chemical oxygen demand (COD) of the sediment. (author)

  10. Storm-driven sediment transport in Massachusetts Bay

    Science.gov (United States)

    Warner, J.C.; Butman, B.; Dalyander, P.S.

    2008-01-01

    Massachusetts Bay is a semi-enclosed embayment in the western Gulf of Maine about 50 km wide and 100 km long. Bottom sediment resuspension is controlled predominately by storm-induced surface waves and transport by the tidal- and wind-driven circulation. Because the Bay is open to the northeast, winds from the northeast ('Northeasters') generate the largest surface waves and are thus the most effective in resuspending sediments. The three-dimensional oceanographic circulation model Regional Ocean Modeling System (ROMS) is used to explore the resuspension, transport, and deposition of sediment caused by Northeasters. The model transports multiple sediment classes and tracks the evolution of a multilevel sediment bed. The surficial sediment characteristics of the bed are coupled to one of several bottom-boundary layer modules that calculate enhanced bottom roughness due to wave-current interaction. The wave field is calculated from the model Simulating WAves Nearshore (SWAN). Two idealized simulations were carried out to explore the effects of Northeasters on the transport and fate of sediments. In one simulation, an initially spatially uniform bed of mixed sediments exposed to a series of Northeasters evolved to a pattern similar to the existing surficial sediment distribution. A second set of simulations explored sediment-transport pathways caused by storms with winds from the northeast quadrant by simulating release of sediment at selected locations. Storms with winds from the north cause transport southward along the western shore of Massachusetts Bay, while storms with winds from the east and southeast drive northerly nearshore flow. The simulations show that Northeasters can effectively transport sediments from Boston Harbor and the area offshore of the harbor to the southeast into Cape Cod Bay and offshore into Stellwagen Basin. This transport pattern is consistent with Boston Harbor as the source of silver found in the surficial sediments of Cape Cod Bay and

  11. Microbial biogeography of San Francisco Bay sediments

    Science.gov (United States)

    Lee, J. A.; Francis, C. A.

    2014-12-01

    The largest estuary on the west coast of North America, San Francisco Bay is an ecosystem of enormous biodiversity, and also enormous human impact. The benthos has experienced dredging, occupation by invasive species, and over a century of sediment input as a result of hydraulic mining. Although the Bay's great cultural and ecological importance has inspired numerous surveys of the benthic macrofauna, to date there has been almost no investigation of the microbial communities on the Bay floor. An understanding of those microbial communities would contribute significantly to our understanding of both the biogeochemical processes (which are driven by the microbiota) and the physical processes (which contribute to microbial distributions) in the Bay. Here, we present the first broad survey of bacterial and archaeal taxa in the sediments of the San Francisco Bay. We conducted 16S rRNA community sequencing of bacteria and archaea in sediment samples taken bimonthly for one year, from five sites spanning the salinity gradient between Suisun and Central Bay, in order to capture the effect of both spatial and temporal environmental variation on microbial diversity. From the same samples we also conducted deep sequencing of a nitrogen-cycling functional gene, nirS, allowing an assessment of evolutionary diversity at a much finer taxonomic scale within an important and widespread functional group of bacteria. We paired these sequencing projects with extensive geochemical metadata as well as information about macrofaunal distribution. Our data reveal a diversity of distinct biogeographical patterns among different taxa: clades ubiquitous across sites; clades that respond to measurable environmental drivers; and clades that show geographical site-specificity. These community datasets allow us to test the hypothesis that salinity is a major driver of both overall microbial community structure and community structure of the denitrifying bacteria specifically; and to assess

  12. Beryllium-10 in Chesapeake Bay sediments: an indicator of sediment provenance

    International Nuclear Information System (INIS)

    Helz, G.R.; Valette-Silver, Nathalie

    1992-01-01

    In a plot of 10 Be vs. Fe, central Chesapeake Bay sediments can be segregated into distinct units. This plot reveals an unexpected, statistically significant difference between sediments on the eastern and western flanks of the main channel, implying different origins. Although the 10 Be concentrations in sediments from these two regions span as much as an order of magnitude range, the 10 Be/Fe ratios vary by an amount approximating analytical error alone. The large concentration ranges are ascribed to hydraulic sorting, which can produce variance in composition while not affecting ratios between grain surface components such as Fe and Be. On the basis of 10 Be/Fe signatures, sediments on the western flank of the main channel appear to have been derived from the Susquehanna or another Piedmont/Appalachian river. Sediments on the eastern flank may have been transported from the south, by landward flowing bottom currents, or may be relics of a Pleistocene estuarine system. Conditions under which 10 Be may prove a useful tool in sediment provenance studies elsewhere are discussed. (Author)

  13. POTENTIAL HAZARDS OF SEDIMENT IN KENDARI BAY, SOUTHEAST SULAWESI

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    Nur Adi Kristanto

    2017-07-01

    Full Text Available Kendari bay is located in front of Kendari city. There are two harbors in the inner part of bay which very important to support economic activities such as shipping and passenger transportation. The result of coastal characteristic mapping and physical oceanography survey show various coastal morphology, vegetation, weathering processes, sedimentation, currents, and water depth and sea floor morphology. Kendari bay is an enclosed bay; the area is wide in the inner part and narrow in mouth of bay (outlet, the morphology look like a bottle’s neck. Numerous mouth rivers are concentrate around the bay. The rivers load material from land since erosion on land is intensive enough. There is indication that sediment supplies from land trough river mouth not equivalent with outlet capacity. Sediment load is trapped in the inner bay caused the outlet morphology. So high sediment rate play an important role in the process of shallow of water depth in Kendari bay. This condition make the Kendari bay is a prone area of sediment hazard due to height rate of sedimentary process. Therefore, to anticipate the hazards, precaution should be taken related to the Kendari bay as the center of activities in southeast of Sulawesi. The further survey is needed such as marine geotechnique and on land environmental to collect data, which can be used as database for development planning. Key words: Potential hazard, sediment, Kendari Bay Teluk

  14. Soft sediment dwelling macro-invertebrates of Rajapur Bay, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Parulekar, A.H.

    Thirtyfour species of soft sediment dwelling macro-invertebrates were recorded in Rajapur Bay at the proposed effluent discharge location of nuclear power plant. The fauna mainly composed of polychaetes (42.52%), molluscs (39.03%), crustaceans (7...

  15. Literature Review of Unconsolidated Sediment in San Francisco Bay and Nearby Pacific Ocean Coast

    Directory of Open Access Journals (Sweden)

    Barry R. Keller

    2009-09-01

    Full Text Available A review of the geologic literature regarding sedimentation in the San Francisco Bay estuarine system shows that the main part of the bay occupies a structural tectonic depression that developed in Pleistocene time. Eastern parts, including San Pablo Bay and Suisun Bay, have had sedimentation throughout late Mesozoic and Tertiary. Carquinez Strait and the Golden Gate may represent antecedent stream erosion. Sedimentation has included estuarine, alluvial, and eolian deposition. The ages of estuarine deposition includes the modern high sea level stand and earlier Pleistocene interglacial periods. Sediment sources can be generally divided into the Coast Ranges, particularly the Franciscan Complex, and “Sierran.” Much of the estuarine system is floored by very fine sediment, with local areas of sand floor. Near the Golden Gate, sediment size decreases in both directions away from the deep channel. Bedforms include sand waves (submarine dunes, flat beds, and rock and boulders. These are interpreted in terms of dominant transport directions. Near the Golden Gate is an ebb-tidal delta on the outside (including San Francisco bar and a flood-tidal delta on the inside (parts of Central Bay. The large tidal prism causes strong tidal currents, which in the upper part of the estuary are normally much stronger than river currents, except during large floods. Cultural influences have altered conditions, including hydraulic mining debris, blasting of rocks, dredging of navigation channels, filling of the bay, and commercial sand mining. Many of these have served to decrease the tidal prism, correspondingly decreasing the strength of tidal currents.

  16. Polychlorinated naphthalenes (PCNs) in riverine and marine sediments of the Laizhou Bay area, North China

    International Nuclear Information System (INIS)

    Pan Xiaohui; Tang Jianhui; Chen Yingjun; Li Jun; Zhang Gan

    2011-01-01

    PCN congeners were analyzed in marine and riverine sediments of the Laizhou Bay area, North China. Concentrations of PCNs ranged from 0.12 to 5.1 ng g -1 dry weight (dw) with a mean value of 1.1 ng g -1 dw. The levels of PCNs varied largely, with industrial group approximately ten folds higher than those of the rural in riverine sediment. A strong impact by direct discharge from local factories was suggested. Similar compositional profiles were found within groups. High resemblance of compositional profiles between industrial samples and Halowax 1014 was observed. It was indicated that PCNs in riverine sediments were mainly from release of industrial usage, with additional contributions from industrial thermal process at certain sites. In marine sediments, it was suggested that PCNs along the coast of Laizhou Bay were mainly controlled by riverine input. While in the central bay, PCN distributions were possibly impacted by combined multiple factors. - Highlights: → We investigated the PCN levels both in the riverine and marine surface sediments of Laizhou Bay. → PCN concentrations in the river sediments of industrial group were ten times higher than in the rural group. → Leakage from industrial materials and thermal processes were the major sources. → PCNs in the coastal sites were more influenced by the river discharge. → In the centre bay, PCN distributions were possibly impacted by combined multiple factors. - A systematic sampling of riverine and marine sediments was conducted in Laizhou Bay area to investigate the distribution and possible sources of PCNs.

  17. Particle fluxes in the Bay of Bengal measurEd. by sediment traps

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaswamy, V.; Parthiban, G.

    Particle fluxes were measured between October, 1987 and March, 1988 using six automated time series sediment traps at three locations in the northern, central and southern Bay of Bengal. Particle fluxes varied between 16.8 and 345 mg m/2 day/1...

  18. Short Term Sediment Exchange Between Marshes and Bays Using Beryllium-7 as a Tracer, Fourleague Bay, Louisiana.

    Science.gov (United States)

    Restreppo, G. A.; Bentley, S. J.; Xu, K.; Wang, J.

    2016-12-01

    Modern delta models focus on the availability and exchange of coarse sediment as one of the major factors of deltaic growth or decay. Fine-grained sediment exchange within a river's delta is relatively poorly understood, as is the impact that this exchange has on land building and land loss. To better understand the dynamics of fine grain sediment exchange between river mouth, adjacent bays, and marshland, sediment cores from Fourleague Bay, LA, were collected and analyzed for 7Be, a naturally occurring radioisotope that serves as a marker for recently deposited sediment. Time-series push cores were collected every two months at ten sites, five located across a longitudinal transect in the middle bay and five located along adjacent marshes, from May 2015 to May 2016. All sites fall within 11 to 28 km of the Atchafalaya Delta, along a gradient extending towards the open ocean. Cores were extruded in 2 cm intervals, dried, ground, and analyzed via gamma spectrometry for the presence of 7Be. Inventories of 7Be were then calculated and used to determine bimonthly sedimentation rates over the course twelve months. Sediment deposition on the bay floor and marsh surface were then compared to Atchafalaya River discharge, wind speed and direction, and wave action. Preliminary results indicate patterns of initial fluvial sediment transfer from river to bay floor, then bay floor to marsh surface, with decreasing fluvial influence towards the open ocean. Sediment transport from bay to marsh appears to be coupled with meteorological forcing that induces bay-floor sediment resuspension and the flooding of marsh surfaces. This indirect mechanism of fluvial sediment supply to wetland surfaces may extend the region of influence for sediment delivery from man-made river-sediment diversions.

  19. Sediment Characterization in St. Alban's Bay, VT

    Science.gov (United States)

    Nethercutt, S.; Manley, T.; Manley, P.

    2017-12-01

    St. Alban's Bay within Lake Champlain is plagued with harmful algal blooms. With future intensification due to climate change, a multidisciplinary program (BREE-Basin Resilience to Extreme Events) was initiated in 2016. In order to assess the mobilization of harmful nutrients from sediment resuspension events and riverine input, 74 sediment samples were collected in a grid fashion throughout St. Alban's Bay. Sediments were deflocculated and analyzed using a LA920 Horiba laser scattering particle size distribution analyzer to define the frequency of sediment sizes from clay to sand. Gridded surfaces of mean sortable silt percentage, silt percentage, sand percentage, and clay percentage were used to represent the sediment distribution of the region. A plot of diameter versus frequency showed the bimodal nature of some of the sediments, with one peak at about 10 microns diameter (silt) and the second at about 525 microns diameter (sand). The data showed an extremely low percentage of clay relative to that of sand and silt. The highest frequencies of sortable silt, which represents the most easily mobilized particle size, are found in the deepest areas of the bay, suggesting that these regions are where dominant bottom flow occurs. The high occurrence of sortable silt in the St. Alban's Bay does suggest that sediment mobilization, and therefore nutrient mobilization has the potential to occur. These data combined with high-resolution multibeam and hydrodynamic data will allow for future models of water flow and remobilization studies in the future.

  20. Heavy metals in superficial sediment of Algiers Bay

    International Nuclear Information System (INIS)

    Benamar, M.A.; Toumert, C.L.; Chaouch, L.; Bacha, L.; Tobbeche, S.

    1996-01-01

    Sediment samples were collected in 33 stations from the bay of Algiers for the potential sources of pollution. the analyses were made x-ray fluorescence (XRF) and atomic absorption spectrometry (AAS) the results give information about level of concentrations morphology of the bay (funnel form of bay). only Co,Mn,Fe, and Cd present a particular repartition (unrelated to the sedimentary facies). the level pollution bu heavy metals of the bottom sediments in algiers bay have been compared with those of Surkouk considered as a region with low anthropogenic activities

  1. Polycyclic aromatic hydrocarbons in sediments and mussels of Corral Bay, south central Chile.

    Science.gov (United States)

    Palma-Fleming, Hernan; P, Adalberto J Asencio; Gutierrez, Elena

    2004-03-01

    PAHs were measured in sediments and mussels (Mytilus chilensis) from Carboneros and Puerto Claro, located in Corral Bay, Valdivia. According to the ratio of phenanthrene/anthracene and fluoranthene/pyrene concentrations, these sites are medium polluted with PAHs originating mainly from pyrolytic sources. Fluoranthene was the major component measured in mussels (3.1-390 ng g(-1) dry weight) and sediments (6.9-74.1 ng g(-1) dry weight). In general, mussels were mainly exposed to the dissolved fraction of the lower molecular weight PAHs (tri- and tetra-aromatics) while the higher molecular ring systems (penta- and hexa-aromatics) were more bioavailable to sediments. Mussel PAHs content was relatively constant, with the exception of the 1999 summer season (March), when higher concentration values were found in both sites; however, PAHs residues in sediments showed a temporal variation.

  2. Predominant Nearshore Sediment Dispersal Patterns in Manila Bay

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    Fernando Siringan

    1997-12-01

    Full Text Available Net nearshore sediment drift patterns in Manila Bay were determined by combining the coastal geomorphology depicted in 1 : 50,000scale topographic maps and Synthetic Aperture Radar (SAR images, with changes in shoreline position and predominant longshore current directions derived from the interaction of locally generated waves and bay morphology.Manila Bay is fringed by a variety of coastal subenvironments that reflect changing balances of fluvial, wave, and tidal processes. Along the northern coast, a broad tidal-river delta plain stretching from Bataan to Bulacan indicates the importance of tides, where the lateral extent of tidal influences is amplified by the very gentle coastal gradients. In contrast, along the Cavite coast sandy strandplains, spits, and wave-dominated deltas attest to the geomorphic importance of waves that enter the bay from the South China Sea.The estimates of net sediment drift derived from geomorphological, shoreline-change, and meteorological information are generally in good agreement. Sediment drift directions are predominantly to the northeast along Cavite, to the northwest along Manila and Bulacan, and to the north along Bataan. Wave refraction and eddy formation at the tip of the Cavite Spit cause southwestward sediment drift along the coast from Zapote to Kawit. Geomorphology indicates that onshore-offshore sediment transport is probably more important than alongshore transport along the coast fronting the tidal delta plain of northern Manila Bay. Disagreements between the geomorphic-derived and predicted net sediment drift directions may be due to interactions of wave-generated longshore currents with wind- and tide-generated currents.

  3. Magnetic and mineralogical properties of central Baffin Bay sediments since the Last Glacial Maximum

    Science.gov (United States)

    Simon, Q.; St-Onge, G.; Hillaire-Marcel, C.

    2011-12-01

    Magnetic and mineralogical properties of terrigenous sediments from the deep central Baffin Bay (HU2008-029-016PC - 70°46,14N/-64°65,77W - 2063 m) were analyzed as a means of linking sedimentological changes to ice-margin dynamics along the surrounding coastlines of W. Greenland, E. Baffin Island and N.E. Ellesmere Island since the Last Glacial Maximum (LGM). A chronology based on relative paleointensity (RPI) and secular variation (PSV) in sections where magnetism properties were suitable has been set. The age-model yields a low mean sedimentation rate varying between 4 - 8 cm/kyr along the core and illustrates a significant increase during Termination 1. Carbonate content increases drastically from 16 ka due to increasing supplies of dolomitic material from dolostone rocks outcropping in the Canadian Arctic Archipelago and associated with inputs from the Innuitian Ice Sheet margin. The magnetic properties demonstrate major changes during the deglaciation and especially during Heinrich event 1 (H1), the Younger Dryas (YD) and throughout the Holocene. Very low median destructive field (MDF) of the natural remanent magnetization (NRM) values are observed during the 11.5 - 12.6 ka (YD) and 14.8 - 16 (H1) ka intervals, and are reflecting coarser magnetic grains. Similarly, the kARM/kLF grain-size ratio shows coarser magnetic grain size during the H1 and YD intervals, and finer magnetic grains during the LGM (19 - 22 ka). During the LGM, "glacial flour" formed by mechanical grinding of rocks by ice sheets released finer magnetic grains from lateral source (e.g., Greenland continental shelf). On the contrary, during the YD and H1 periods, icebergs released coarser magnetic grains from a northern source (axial source). The Holocene is marked by the highest median destructive field (MDF) and ARM20mT/ARM0mT values of the core, indicating an increased proportion of finer magnetic grains during this interval. Together with the large increase in the silt fraction, these

  4. Organic Matter Remineralization Predominates Phosphorus Cycling in the Mid-Bay Sediments in the Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Sunendra, Joshi R.; Kukkadapu, Ravi K.; Burdige, David J.; Bowden, Mark E.; Sparks, Donald L.; Jaisi, Deb P.

    2015-05-19

    The Chesapeake Bay, the largest and most productive estuary in the US, suffers from varying degrees of water quality issues fueled by both point and non–point source nutrient sources. Restoration of the bay is complicated by the multitude of nutrient sources, their variable inputs and hydrological conditions, and complex interacting factors including climate forcing. These complexities not only restrict formulation of effective restoration plans but also open up debates on accountability issues with nutrient loading. A detailed understanding of sediment phosphorus (P) dynamics enables one to identify the exchange of dissolved constituents across the sediment- water interface and aid to better constrain mechanisms and processes controlling the coupling between the sediments and the overlying waters. Here we used phosphate oxygen isotope ratios (δ18Op) in concert with sediment chemistry, XRD, and Mössbauer spectroscopy on the sediment retrieved from an organic rich, sulfidic site in the meso-haline portion of the mid-bay to identify sources and pathway of sedimentary P cycling and to infer potential feedback effect on bottom water hypoxia and surface water eutrophication. Isotope data indicate that the regeneration of inorganic P from organic matter degradation (remineralization) is the predominant, if not sole, pathway for authigenic P precipitation in the mid-bay sediments. We interpret that the excess inorganic P generated by remineralization should have overwhelmed any bottom-water and/or pore-water P derived from other sources or biogeochemical processes and exceeded saturation with respect to authigenic P precipitation. It is the first research that identifies the predominance of remineralization pathway against remobilization (coupled Fe-P cycling) pathway in the Chesapeake Bay. Therefore, these results are expected to have significant implications for the current understanding of P cycling and benthic-pelagic coupling in the bay, particularly on the

  5. Geochemistry of sediments in the Back Bay and Yellowknife Bay of the Great Slave Lake

    International Nuclear Information System (INIS)

    Mudroch, A.; Joshi, S.R.; Sutherland, D.; Mudroch, P.; Dickson, K.M.

    1989-01-01

    Gold mining activities have generated wastes with high concentrations of arsenic and zinc in the vicinity of Yellowknife, Northwest Territories, Canada. Some of the waste material has been discharged into Yellowknife Bay of Great Slave Lake. Concentrations of arsenic and zinc were determined in sediment cores collected at the depositional areas of Yellowknife Bay. Sedimentation rates were estimated using two different radiometric approaches: the depth profiles of cesium 137 and lead 210. Geochemical analysis of the sediment cores indicated input of similar material into sampling areas over the past 50 yr. Age profiles of the sediment constructed from the radionuclide measurements were used to determine historical trends of arsenic and zinc inputs into Yellowknife Bay. The historical record was in good agreement with implemented remedial actions and the usage patterns of both elements. 16 refs., 6 figs., 3 tabs

  6. Heavy Metal Pollution Evolution in Sediments from Urdaibai Bay (Spain)

    International Nuclear Information System (INIS)

    Soto, J.; Soto, J.A.; Corral, D.; Gelen, A.; Diaz, O.; Navas, A.

    2003-01-01

    Full Text: The Urdaibai bay is a biosphere reservoir located in the north of Spain. The mayor components of bay sediments come from marls and clays eroded which are deposited together with metallic pollutants present in water, air and rain. For this reason it is possible to study the temporal evolution of the bay pollution by measuring the heavy metal concentrations in the sediments and considering the correspondence with its age. To this aim, sediments cores were taken in two different points of the Urdaibai bay. The cores were cut into 1 cm thick horizontal sections. Sediment dating was performed using a low background gamma spectrometry with GeHP to determine Cs-137, Ra-226 and Pb-210 activities and applying the CIC and CRS models. The heavy metal concentrations in sediments were determined by ICP-MS. The obtained results in one of the studied positions show an increment of the Pb, Zn, Ni, Cu and Cr concentrations in the first 10 cm of the sediment core. This fact can be related to an increase of the bay pollution in the last 100 years. In the second studied core the heavy metal concentrations are constant in depth or lower in the superficial layers. This could be due to an increment the deposition rate of eroded material

  7. Rate of Loaded Sediments in Honda Bay, Puerto Princesa City, Palawan, Philippines

    Directory of Open Access Journals (Sweden)

    Joel Becira

    2006-06-01

    Full Text Available A study in Honda Bay, Puerto Princesa City, Palawan, Philippines was conducted to determine and compare the rate of loaded sediments of and among six sites in Honda Bay and during two seasons, and to discuss sedimentation rate in relation to selected environmental parameters commencing on April 2003 to November 2003.Results showed that the Babuyan River significantly contributed to the amounts of sediments being loaded to Honda Bay, Puerto Princesa City of which the amount of sediments loaded between the two sampling season and among the six sampling events had no significant difference. Sediment's color and texture affirmed the land-based activities in Babuyan and Mauyon watersheds, which eventually carried into the Bay during storm weather condition.The amount of trapped sediments in all stations is probably affected by the river's discharge capacity and the river's water velocity, although the duration sediment traps were mounted could also affect the measurement of sedimentation rate.

  8. Concentrations of PAHs (Polycyclicaromatic Hydrocarbons Pollutant in Sediment of The Banten Bay

    Directory of Open Access Journals (Sweden)

    Khozanah Munawir

    2018-02-01

    Full Text Available Banten Bay is end of stream for a few rivers from Banten mainland where many manufactures and petrochemical industries are built. This may give environmental pressure of water quality of the bay due to pollutant input, such as Polycyclic Aromatic Hydrocarbons (PAHs. This study is to identify those pollutants and determine their total concentration and distribution in sediments. Surface sediment samples were collected in four zones: inner coastline within the bay, middle bay, coastline off the bay and outer of the Bay in April 2016. PAH components were extracted and measured using a gas chromatography-mass spectrometry. Levels of total PAHs in sediments in inner coastline within the bay ranged between 0.381-2.654 ppm with an average of 1.288 ppm, middle of the bay ranged between 0.747-1.762 ppm with an average of 1.198 ppm, outer of the bay ranged between 0.192-1.394 ppm with an average of 0.921 ppm, and east coast of the bay ranged between 0.191-1.394 ppm and an average of 0.778 ppm. The levels of total PAH contamination is apparently lower than those of PAH threshold in sediments (i.e. 4.5 ppm. Keywords: PAHs (Polycyclic Aromatic Hydrocarbons, Banten Bay

  9. Observation on Heavy Metals in Sediment of Jakarta Bay Waters

    Directory of Open Access Journals (Sweden)

    Abdul Rozak

    2007-04-01

    Full Text Available Observation on heavy metals in Jakarta Bay, from June and September 2003. Heavy metals Pb in sediment at the West have been conductet of Jakarta Bay Waters varied between Pb = 8,49-31,22 ppm, Cd = <0,001-0,47 ppm, Cu = 13,81-193,75 ppm, Zn = 82,18-533,59 ppm and Ni = 0,99-35,38 ppm,while those at the Center of Jakarta Bay, varied between Pb = 2,21-69,22 ppm, Cd = <0,001-0,28 ppm, Cu = 3,36-50,65 ppm, Zn = 71,13-230,54 ppm and Ni = 0,42-15,58 ppm and at the East of Jakarta Bay, Pb content varied between 0,25-77,42 ppm, Cd = <0,001-0,42 ppm, Cu = 0,79-44,94 ppm, Zn = 93,21-289,00 ppm and Ni = 0,42-128,47 ppm. Hevy metals content in sediment the West of Jakarta Bay was high of equivalent the Center and East of Jakarta Bay. At than those composition sediment at the west was black, that indicated high heavy metals content.

  10. A Tidally Averaged Sediment-Transport Model for San Francisco Bay, California

    Science.gov (United States)

    Lionberger, Megan A.; Schoellhamer, David H.

    2009-01-01

    A tidally averaged sediment-transport model of San Francisco Bay was incorporated into a tidally averaged salinity box model previously developed and calibrated using salinity, a conservative tracer (Uncles and Peterson, 1995; Knowles, 1996). The Bay is represented in the model by 50 segments composed of two layers: one representing the channel (>5-meter depth) and the other the shallows (0- to 5-meter depth). Calculations are made using a daily time step and simulations can be made on the decadal time scale. The sediment-transport model includes an erosion-deposition algorithm, a bed-sediment algorithm, and sediment boundary conditions. Erosion and deposition of bed sediments are calculated explicitly, and suspended sediment is transported by implicitly solving the advection-dispersion equation. The bed-sediment model simulates the increase in bed strength with depth, owing to consolidation of fine sediments that make up San Francisco Bay mud. The model is calibrated to either net sedimentation calculated from bathymetric-change data or measured suspended-sediment concentration. Specified boundary conditions are the tributary fluxes of suspended sediment and suspended-sediment concentration in the Pacific Ocean. Results of model calibration and validation show that the model simulates the trends in suspended-sediment concentration associated with tidal fluctuations, residual velocity, and wind stress well, although the spring neap tidal suspended-sediment concentration variability was consistently underestimated. Model validation also showed poor simulation of seasonal sediment pulses from the Sacramento-San Joaquin River Delta at Point San Pablo because the pulses enter the Bay over only a few days and the fate of the pulses is determined by intra-tidal deposition and resuspension that are not included in this tidally averaged model. The model was calibrated to net-basin sedimentation to calculate budgets of sediment and sediment-associated contaminants. While

  11. Aromatic hydrocarbon concentrations in sediments of Placentia Bay, Newfoundland

    International Nuclear Information System (INIS)

    Kiceniuk, J.W.

    1992-01-01

    A study was conducted to examine the potential for contamination of recent sediments with polycyclic aromatic hydrocarbons due to tanker and refinery activity in Placentia Bay, Newfoundland, an area without large local anthropogenic sources of aromatics. Sediment samples were taken from the vicinity of the Come By Chance refinery, Woody Island, Wild Cove, and Port Royal Arm, all in the north end of the bay. The samples were extracted by two methods, dichloromethane extraction of dried sediment for determination of total aromatic hydrocarbon content and hexane extraction of wet sediment for estimation of the bioavailability of hydrocarbons and determination of more volatile compounds. Class analysis of aromatic hydrocarbons was conducted on a NH 2 column with detection at 255 nm. Total concentrations of di-tricyclic aromatics were highest at the Woody Island site (0.6 μg/g). The sediments from the Come By Chance site, Wild Cove, and Port Royal Arm sediments contained 0.3, 0.1, and 0.2 μg/g respectively. The hexane extracts from Come By Chance were lowest in di-tricyclic aromatics (0.007 μg/g), with the other sites being equal in concentration (0.01 μg/g). It is evident from the study that aromatic hydrocarbon concentrations in Placentia Bay are elevated in some parts of the bay in the absence of local combustion sources, and that the most likely source is petroleum. 12 refs., 5 figs., 2 tabs

  12. Studies of movement of sediments in Santos bay

    International Nuclear Information System (INIS)

    Bandeira, J.V.; Aun, P.E.; Bomtempo, V.L.; Salim, L.H.; Minardi, P.S.P.; Santos, J.A.

    1990-01-01

    In the years of 1973, 74, 80, 81 and 85 several studies were performed at Santos bay, using radioactive tracers, with the following main objectives: to evaluate the behaviour (on the bottom and in suspension) of the mixture of silt and clay which is dredged from the estuary and from its access channel and dumped at pre-determined sites, in the bay and surrounding regions, with the objective of optimizing dredging disposal operations; to quantify the movement of sandy sediments on the bottom, in 3 areas of the bay, in summer and winter conditions, to obtain pertinent information related to the siltation of the access channel. As results of these studies, it was found that: the ancient dumping site, near Itaipu Point, in the western limit of the bay, was inadequate, since the material could return to the bay and to the estuary. The dumping site was moved to a region at the south of Moela Island, located eastwards relative to the bay, which brought substantial economies in dredging works; the bottom sediment transport was quantified, following clouds of tagged materials for about 8 months, thus obtaining important conclusions about transport rates in different regions of the bay. An analysis of the intervening hydrodynamic agents is also presented. (author) (L.J.C.)

  13. Particle-borne radionuclides as tracers for sediment in the Susquehanna River and Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Donoghue, J F [Florida State Univ., Tallahassee, FL (USA). Dept. of Geology; Bricker, O P [Geological Survey, Reston, VA (USA). Water Resources Div.; Olsen, C R [Oak Ridge National Lab., TN (USA)

    1989-10-01

    The Chesapeake Bay receives nearly 1,000,000 tonnes of sediment annually from its major tributary, the Susquehanna River. The pattern of deposition of this sediment affects the lifetime of the estuarine resource and the fate of any sediment-borne contaminants. Previous estimates of the extent to which Susquehanna River sediment is transported down the Chesapeake have differed considerably. By use of reactor-generated radionuclides adsorbed on the river sediment, a sediment budget has been compiled for the upper Chesapeake Bay and the reservoirs on the lower Susquehanna. Reservoirs impound nearly 1,400,000 tonnes of sediment annually behind the power dams on the lower Susquehanna River. Without the dams, sediment delivery to the upper bay would more than double. The uppermost Chesapeake Bay, within and above the turbidity maximum, retains virtually all of the fluvial sediment delivered to it. The result is an annual sedimentation rate of approximately 3 mm yr{sup -1} in the upper bay, an infilling rate that is nearly equal to the regional rate of sea level rise. (author).

  14. Particle-borne radionuclides as tracers for sediment in the Susquehanna River and Chesapeake Bay

    International Nuclear Information System (INIS)

    Donoghue, J.F.

    1989-01-01

    The Chesapeake Bay receives nearly 1,000,000 tonnes of sediment annually from its major tributary, the Susquehanna River. The pattern of deposition of this sediment affects the lifetime of the estuarine resource and the fate of any sediment-borne contaminants. Previous estimates of the extent to which Susquehanna River sediment is transported down the Chesapeake have differed considerably. By use of reactor-generated radionuclides adsorbed on the river sediment, a sediment budget has been compiled for the upper Chesapeake Bay and the reservoirs on the lower Susquehanna. Reservoirs impound nearly 1,400,000 tonnes of sediment annually behind the power dams on the lower Susquehanna River. Without the dams, sediment delivery to the upper bay would more than double. The uppermost Chesapeake Bay, within and above the turbidity maximum, retains virtually all of the fluvial sediment delivered to it. The result is an annual sedimentation rate of approximately 3 mm yr -1 in the upper bay, an infilling rate that is nearly equal to the regional rate of sea level rise. (author)

  15. 137Cs and 210Pb distribution in Manila Bay sediment

    International Nuclear Information System (INIS)

    Sta. Maria, Efren J.; Madrid, Jordan F.; Olivares, Ryan U.; Bulos, Adelina DM; Dayaon, Jennyvi P.; Asa, Anie Day DC; Sombrito, Elvira Z.

    2011-01-01

    Two radionuclides were measured in surface sediment samples taken from geographically distributed sections of Manila Bay, namely cesium-137 ( 137 Cs) and lead-210 ( 210 Pb). Results indicated a noticeable change in the radioactivity concentration levels in sediments collected in 2005 and 2010, with a median concentration of 1.0 and 2.64 Bq kg -1 , respectively. Higher levels of 137 Cs radioactivity were measured in the northern and inner portion of the bay adjacent to major river systems, agricultural and highly industrialized urban areas. 137 Cs isotope increased in activity in most of the samples especially in the northwestern areas of Bataan and Pampanga with five times more than the activity from the first sampling measurements. Nevertheless, radioactivity concentrations observed in surface sediments along the bay are within the range of radioactivity in several areas monitored in the Northern Hemisphere. The country has been frequented by tropical cyclones and storms that have caused erosion, which may have introduced elevated material input in the bay. In addition, wind-driven circulation especially in the shallower areas of the bay is a possibility for the substantial sediment movement and accumulation along this coast. Conversely, areas with higher 137 Cs have lower values of 210 Pb. In an undisturbed environment, 210 Pb deposition values are assumed nearly constant. Hence, changes in the radioactivity concentration levels of these radionuclides can be an indicator of pollution input from land-based sources, sediment movement and reworking in the coastal areas. At present, there is very limited information on the radioactivity level of various radioisotopes in Manila Bay.The data obtained are benchmark values against which changes that will be occurring in the bay can be assessed. (author)

  16. Sedimentation processes in a coral reef embayment: Hanalei Bay, Kauai

    Science.gov (United States)

    Storlazzi, C.D.; Field, M.E.; Bothner, Michael H.; Presto, M.K.; Draut, A.E.

    2009-01-01

    Oceanographic measurements and sediment samples were collected during the summer of 2006 as part of a multi-year study of coastal circulation and the fate of terrigenous sediment on coral reefs in Hanalei Bay, Kauai. The goal of this study was to better understand sediment dynamics in a coral reef-lined embayment where winds, ocean surface waves, and river floods are important processes. During a summer period that was marked by two wave events and one river flood, we documented significant differences in sediment trap collection rates and the composition, grain size, and magnitude of sediment transported in the bay. Sediment trap collection rates were well correlated with combined wave-current near-bed shear stresses during the non-flood periods but were not correlated during the flood. The flood's delivery of fine-grained sediment to the bay initially caused high turbidity and sediment collection rates off the river mouth but the plume dispersed relatively quickly. Over the next month, the flood deposit was reworked by mild waves and currents and the fine-grained terrestrial sediment was advected around the bay and collected in sediment traps away from the river mouth, long after the turbid surface plume was gone. The reworked flood deposits, due to their longer duration of influence and proximity to the seabed, appear to pose a greater long-term impact to benthic coral reef communities than the flood plumes themselves. The results presented here display how spatial and temporal differences in hydrodynamic processes, which result from variations in reef morphology and orientation, cause substantial variations in the deposition, residence time, resuspension, and advection of both reef-derived and fluvial sediment over relatively short spatial scales in a coral reef embayment.

  17. A reevaluation of the late quaternary sedimentation in todos os Santos Bay (BA, Brazil

    Directory of Open Access Journals (Sweden)

    GUILHERME C. LESSA

    2000-12-01

    Full Text Available Todos os Santos Bay is a large ( 1000 km², structurally controlled tidal bay in northeast Brazil. Three main drainage basins debouch into the bay, providing a mean freshwater discharge of 200 m³/s (prior to 1985, or less than 1% of the spring tidal discharge through the bay mouth. Based on the result of several sedimentological studies performed in the 1970's, five surface sedimentary facies were identified inside the bay, namely i transgressive siliciclastic marine sand facies; ii transgressive bay sand-mud facies; iii a transgressive carbonate marine sand facies; iv regressive bay-mud facies, and v regressive fluvial sand facies. The spatial distribution of these facies would follow, somewhat closely, the hydrodynamic-energy distribution inside the bay. Seismic profiles along the bay bottom indicate the existence of several paleochannels, 5-10 m deep, blanketed at least by three different sedimentary units. The topmost sedimentary unit, 5-20 m thick, appears to be associated with the regressive bay-mud facies, and assuming that it was laid down within the last 5000 years, sedimentation rates for the central and northeastern part of the bay would average at 2,4 mm/y.

  18. Assessment of sediment contamination in Casco Bay, Maine, USA

    Energy Technology Data Exchange (ETDEWEB)

    Wade, Terry L. [Geochemical and Environmental Research Group, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States); Sweet, Stephen T. [Geochemical and Environmental Research Group, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: sweet@gerg.tamu.edu; Klein, Andrew G. [Geography Department, Texas A and M University, 814B Eller O and M Building, College Station, TX 77843 (United States)

    2008-04-15

    The current status of contaminant concentrations in Casco Bay, decadal trends of these contaminants and changes in their geographical distribution are assessed using sediment samples collected approximately 10 years apart. In general, regulated contaminants appeared to be decreasing in concentration. Total PAH and dioxins/furans concentrations did not significantly change over this period. Total organochlorine pesticides, 4,4-DDE, 4,4-DDD, total DDT, PCB, tributyltin and total butyltin decreased in concentration. Trace element concentrations in sediments decreased at the majority of the sampling sites for chromium, nickel, and selenium while arsenic, cadmium, copper, lead, mercury, silver, and zinc remained relatively constant. None of the contaminants measured has increased by more than a factor of 2. Selected sites located in the Inner Bay, where concentrations are higher and new inputs were more likely, showed increased concentrations of contaminants. Most contaminants were not found at concentrations expected to adversely affect sediment biota based on ERL/ERM guidelines. - Sediment studies indicate decadal decreases for many chemical contaminants in Casco Bay.

  19. Assessment of sediment contamination in Casco Bay, Maine, USA

    International Nuclear Information System (INIS)

    Wade, Terry L.; Sweet, Stephen T.; Klein, Andrew G.

    2008-01-01

    The current status of contaminant concentrations in Casco Bay, decadal trends of these contaminants and changes in their geographical distribution are assessed using sediment samples collected approximately 10 years apart. In general, regulated contaminants appeared to be decreasing in concentration. Total PAH and dioxins/furans concentrations did not significantly change over this period. Total organochlorine pesticides, 4,4-DDE, 4,4-DDD, total DDT, PCB, tributyltin and total butyltin decreased in concentration. Trace element concentrations in sediments decreased at the majority of the sampling sites for chromium, nickel, and selenium while arsenic, cadmium, copper, lead, mercury, silver, and zinc remained relatively constant. None of the contaminants measured has increased by more than a factor of 2. Selected sites located in the Inner Bay, where concentrations are higher and new inputs were more likely, showed increased concentrations of contaminants. Most contaminants were not found at concentrations expected to adversely affect sediment biota based on ERL/ERM guidelines. - Sediment studies indicate decadal decreases for many chemical contaminants in Casco Bay

  20. An investigation of recent storm histories using Ground Penetrating Radar at Bay-Bay Spit, Bicol, Central Philippines

    Science.gov (United States)

    Switzer, Adam D.; Pile, Jeremy; Soria, Janneli Lea A.; Siringan, Fernando; Daag, Arturo; Brill, Dominik

    2016-04-01

    The Philippine archipelago lies in the path of seasonal tropical cyclones, and much of the coast is prone to periodic inundation and overwash during storm surges. On example is typhoon Durian a category 3 storm that made landfall on the 30th November 2006, in Bicol province, on the east central Philippine coast. Satellite imagery from May 2007 reveal that Durian breached a sandy spit that runs southeast from the mouth of the Quinale River at Bay-Bay village towards Tabaco City. The imagery also showed that, although the breach site showed signs of partial recovery, geomorphological evidence of the inundation event associated with typhoon Durian still remains. In 2012 we mapped the geomorphological features of Durian. In June 2013 we returned to conduct Ground Penetrating Radar (GPR) surveys on the Bay-Bay spit to investigate potential subsurface evidence of previous storm events. The GPR surveys comprised five, 1.5 km, longshore profiles and 12 cross-shore profiles, of 50 m - 200 m in length. The GPR system used for this study was a Sensors and Software Noggin with 100 Mhz antennas. Near surface velocities were determine using Hyperbolae matching in order to estimate depth. Topographic and positional data were collected using a dGPS system. After minimal processing depth of penetration during the survey varied from 2 - 8 m. The cross-shore GPR profiles reveal at least two erosional events prior to 2006 typhoon Durian, with approximately 10 m of recovery and progradation between each erosion surface. The GPR profiles that captured the erosional features were revisited in September 2013 for trial pitting, stratigraphic description, and sediment sampling. Sediment cores were taken horizontally from the trench walls and vertically from the trench bases to date sediments using Optically Stimulated Luminescence (OSL), which eventually could constrain the timing of the erosional surfaces.

  1. Temporal shifts in reef lagoon sediment composition, Discovery Bay, Jamaica

    Science.gov (United States)

    Perry, Christopher T.; Taylor, Kevin G.; Machent, Philip G.

    2006-03-01

    Discovery Bay, north Jamaica, forms a large (1.5 km wide), deep (up to 56 m) embayment that acts as a sink for reef-derived and lagoonal carbonate sediments. Since the mid-1960s, the bay has also provided a sink for inputs of bauxite sediment that are spilled during loading at a boat terminal constructed within Discovery Bay. Bauxite has accumulated across much of the southern section of the bay with surficial sediments presently composed of up to 35 weight% non-carbonate. Cores recovered from sites on the western side of the bay provide a stratigraphic record of this history of bauxite contamination across water depths from 5 to 25 m. The bauxite-influenced upper sediment horizons are clearly visible in each core from the distinctive red-brown colouration of the sediment. These sediments are composed of approximately 10% non-carbonate (bauxite) and have Fe contents of around 2-3000 μg/g (up to 7000 μg/g). The thickness of this upper bauxite-contaminated sequence increases down transect (approximately 18 cm in the shallowest core, to around 47 cm in the deepest core), and in each core overlies a sequence of 'clean' lagoon carbonates. These typically are poorly sorted carbonate sands with variable amounts of coral rubble. Down-core data on CaCO 3 and Fe content provide a chemical record of decreasing sediment contamination with depth, with the lower 'clean' carbonates composed of only around 2% non-carbonate and coral, mollusc, Amphiroa and Halimeda in the clean lagoon sands, to assemblages dominated by Halimeda and Amphiroa within the surficial sediments. At the deeper sites, no major down-core shifts in sediment constituents occur. These sites thus record a rather complex history of changes in sediment composition and chemistry. Clear shifts in chemistry and stratigraphy occur in all the cores and reflect progressive bauxite contamination in the near-surface horizons. These inputs, however, do not appear to have directly affected carbonate production, since the

  2. Source-to-sink constraints on tectonic and sedimentary evolution of the western Central Range and Cenderawasih Bay (Indonesia)

    Science.gov (United States)

    Babault, Julien; Viaplana-Muzas, Marc; Legrand, Xavier; Van Den Driessche, Jean; González-Quijano, Manuel; Mudd, Simon M.

    2018-05-01

    The island of New Guinea is the result of continent-arc collision that began building the island's Central Range during the late Miocene. Recent studies have shown that rapid subduction, uplift and exhumation events took place in response to rapid, oblique convergence between the Pacific and the Australian plates. The tectonic and sedimentary evolution of Cenderawasih Bay, in the northwestern part of the New Guinea Island is still poorly understood: this bay links a major structural block, the Kepala Burung block, to the island's Central Ranges. Previous studies have shown that Cenderawasih Bay contains a thick (>8 km) sequence of undated sediments. One hypothesis claims that the embayment resulted from a 3 Ma opening created by anticlockwise rotation of the Kepala Burung block with respect to the northern rim of the Australian plate. Alternatively, the current configuration of Cenderawasih Bay could have resulted from the southwest drift of a slice of volcanics and oceanic crust between 8 and 6 Ma. We test these hypotheses using (i) a geomorphologic analysis of the drainage network dynamics, (ii) a reassessment of available thermochronological data, and (iii) seismic lines interpretation. We suggest that sediments started to accumulate in Cenderawasih Bay and onshore in the Waipoga Basin in the late Miocene since the inception of growth of the Central Range, beginning at 12 Ma, resulting in sediment accumulation of up to 12,200 m. This evidence is more consistent with the second hypothesis, and the volume of sediment accumulated means it is unlikely that the embayment was the result of recent (2-3 Ma) rotation of structural blocks. At first order, we predict that infilling is mainly composed of siliciclastics sourced in the graphite-bearing Ruffaer Metamorphic Belt and its equivalent in the Weyland Overthrust. Ophiolites, volcanic arc rocks and diorites contribute minor proportions. From the unroofing paths in the Central Range we deduce two rates of solid phase

  3. Sediment sources and their Distribution in Chwaka Bay, Zanzibar ...

    African Journals Online (AJOL)

    This work establishes sediment sources, character and their distribution in Chwaka Bay using (i) stable isotopes compositions of organic carbon (OC) and nitrogen, (ii) contents of OC, nitrogen and CaCO3, (iii) C/N ratios, (iv) distribution of sediment mean grain size and sorting, and (v) thickness of unconsolidated sediments.

  4. Sediment sources and transport in Kings Bay and vicinity, Georgia and Florida, July 8-16, 1982

    Science.gov (United States)

    Radtke, D.B.

    1985-01-01

    Water quality, bottom-material, suspended-sediment, and current velocity data were collected during July 1982 in Kings Bay and vicinity to provide information on the source and transport of estuarine sediments. Kings Bay and Cumberland Sound, the site of the Poseidon Submarine Base in southeast Georgia, are experiencing high rates of sediment deposition and accumulation, which are causing serious navigational and operational problems. Velocity, bathymetry, turbidity, and bottom-material data suggest sediment transported from lower Kings Bay is accumulating deposits of suspended sediment transported from Cumberland Sound on the floodtide and from upper Kings Bay and the tidal march drained by Marianna Creek on the ebbtide. Suspended-sediment discharges computed for consecutive 13-hr ebbtides and floodtides showed that a net quantity of suspended sediment was transported seaward from upper Kings Bay and Marianna Creek. A net landward transport of suspended sediment computed at the St. Marys Entrance indicated areas seaward of St. Marys Entrance may be supplying sediment to the shoaling areas of the estuary, including lower Kings Bay. (USGS)

  5. Sedimentation rate estimates in Sorsogon Bay, Philippines using 210Pb method

    International Nuclear Information System (INIS)

    Madrid, Jordan F.; Sta. Maria, Efren J.; Olivares, Ryan U.; Aniago, Ryan Joseph; Asa Anie Day DC; Dayaon, Jennyvi P.; Bulos, Adelina DM; Sombrito, Elvira Z.

    2011-01-01

    Sorsogon Bay has experienced a long history of recurring harmful algal blooms over the past few years. In an attempt to establish a chronology of events in the sediment layer, lead-210 ( 210 Pb) dating method has been utilized in estimating sedimentation rates from three selected areas along the bay. Based on the unsupported 210 Pb data and by applying the Constant Initial Concentration (CIC) model, the calculated sedimentation rates were 0.8, 1.3 and 1.8 cm yr 1 for sediment cores collected near the coastal areas of Castilla (SO-01), Sorsogon City (SO-07) and Cadacan River (SO-03), respectively. High sedimentation rates were measured in sediment cores believed to be affected from frequent volcanic ash releases and from areas near human settlement combined with intensive farming and agricultural activities. The collected sediments exhibited non-uniform down core values of dry bulk density and moisture content. This variation in measurements may indicate the general quality and composition of the sediment samples, i.e., amount of organic matter and grain size. The calculated sedimentation rates obtained provided an overview of the sedimentation processes and reflect the land use pattern around the bay which may help in understanding the history and distribution of materials and nutrient input relative to the occurrence of harmful algal bloom in the sediment columns. (author)

  6. Gamma Activation Analysis in the Havana Bay superficial sediments

    International Nuclear Information System (INIS)

    Lopez, N.; Gelen, A.; Diaz Riso, O.; Manso, M.V.; Simon, M.J.; Maslov, A.G.; Gustova, M.V.; Beltran, J.; Soto, J.

    2003-01-01

    A preliminary study of 26 elements of Havana Bay superficial sediments were made using Gamma Activation Analysis. Samples from five zones of Havana Bay were analyzed. The results show a close interrelation between the concentration levels of the studied elements and the contaminant sources

  7. Organochlorine residues in sediments from selected tributaries to Manila Bay, Philippines

    International Nuclear Information System (INIS)

    Bajet, C.M.; Varca, L.M.; Navarro, M.P.

    1999-01-01

    Sediment borne pesticides are the major route of transport of pesticides in the marine environment and benthic dwellers, filter feeders and the flora/fauna closely associated with the sediments could greatly be affected. This paper focuses on the monitoring of organochlorine pesticides in sediments collected from the mouth of rivers draining to Manila Bay and relate to the contribution of inland activities to the overall pollution of the Bay. Sediments from 14-25 tributaries were collected in 1996 to 1998 and analyzed for the presence of HCB, aldrin, dieldrin, lindane, DDT, DDE, DDD, endosulfan I, endosulfan II and endosulfan sulfate using GLC-ECD

  8. A preliminary appraisal of sediment sources and transport in Kings Bay and vicinity, Georgia and Florida

    Science.gov (United States)

    McConnell, J.B.; Radtke, D.B.; Hale, T.W.; Buell, G.R.

    1983-01-01

    Water-quality, bottom-material, suspended-sediment, and current-velocity data were collected during November 1981 in Kings Bay and vicinity to provide information on the sources and transport of estuarine sediments. Kings Bay and Cumberland Sound , the site of the Poseidon Submarine Base in southeast Georgia, are experiencing high rates of sediment deposition and accumulation, which are causing serious navigational and operational problems. Velocity, bathymetry, turbidity, and bottom-material data suggest that the area in the vicinity of lower Kings Bay is accumulating deposits of suspended sediment transported from Cumberland Sound on the floodtide and from upper Kings Bay and the tidal marsh drained by Marianna Creek on the ebbtide. Suspended-sediment discharges computed for consecutive 13-hour ebbtides and floodtides showed that a net quantity of suspended sediment was transported seaward from upper Kings Bay and Marianna Creek. A net landward transport of suspended sediment computed at the St. Marys Entrance indicated areas seaward of St. Marys Entrance may be supplying sediment to the shoaling areas of the estuary, including lower Kings Bay. (USGS)

  9. The geochemistry of coprostanol in waters and surface sediments from Narragansett Bay

    Science.gov (United States)

    LeBlanc, Lawrence A.; Latimer, James S.; Ellis, John T.; Quinn, James G.

    1992-05-01

    A geochemical study of coprostanol (5β-Cholestan-3β-ol) was undertaken, to examine the transport and fate of a compound of moderate polarity and reactivity in the marine environment, and also because of the interest in coprostanol for use as a sewage tracer. During 1985-86, 20 sites in Narragansett Bay, including the major point sources and rivers discharging into the bay estuary, were sampled at four different times. In addition, surface sediments from 26 stations in the bay were collected. The large number and diversity of samples allowed for an assessment of major inputs of sewage into the bay as well as the recent fate of sewage-derived particles in surface sediments. Results from the study revealed that 50% of the total particulate coprostanol entering the bay was discharged into the Providence River, primarily due to inputs from the wastewater treatment facility (WWTF) at Fields Point, as well as input from the Pawtuxet and Blackstone Rivers. In the lower bay, the Newport WWTF was the largest single source of coprostanol (37% of the total particulate coprostanol) to the bay. Effluent concentrations of coprostanol from secondary WWTFs were consistently lower than those of primary treatment facilities, demonstrating the usefulness of corporstanol as an indicator of treatment plant efficiency. The distribution of coprostanol in waters and surface sediments showed a gradient of decreasing concentration downbay. When coprostanol concentrations in surface sediments were normalized to organic carbon (OC) concentrations, elevated levels were seen only in the Providence River, with a more or less even distribution throughout the rest of the bay. Results also suggest that coprostanol degrades more rapidly in the water column compared to the petroleum hydrocarbons (PHCs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), however, it is relatively stable once it is buried in the sediments. Coprostanol concentrations in waters (0·02-0·22

  10. Contribution of chronic petroleum inputs to Narragansett Bay and Rhode Island Sound sediments

    Energy Technology Data Exchange (ETDEWEB)

    Van Vleet, E S; Quin, J G

    1978-05-01

    Sediment cores from Narragansett Bay and Rhode Island Sound have been analyzed for petroleum hydrocarbons and compared with a relatively unpolluted sediment core from the Gulf of Maine. The sediments were analyzed for unbound hydrocarbons, hydrocarbons bound or closely associated with humic substances, and residual hydrocarbons bound or closely associated with the clay mineral or kerogen matrix. Results indicated that in general 90-100% of the hydrocarbons were in the unbound form and could be easily extracted with organic solvents. The petroleum hydrocarbons decreased with depth at all stations. Biogenic hydrocarbons (nC/sub 25/, nC/sub 27/, nC/sub 29/, and nC/sub 31/) made up an increasingly greater percentage of the total with increasing depth. The hydrocarbons in the Narragansett Bay sediments and near surface Rhode Island Sound sediments strongly resembled the hydrocarbons previously reported for the Providence River and upper Narragansett Bay. These petroleum-like hydrocarbons were shown to be largely introduced to the river and bay through chronic inputs from a municipal wastewater treatment plant. These hydrocarbons then undergo sedimentation throughout the entire bay and into Rhode Island Sound. Preliminary calculations indicate that over 0.2 million t (tonne) of petroleum hydrocarbons may be transported to the marine environment annually from municipal treatment plants. Most of these hydrocarbons appear to accumulate in estuarine and coastal sediments.

  11. DDT residues in sediments from the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.; SenGupta, R.

    in the sediments from the Bay of Bengal. Peterson grab and hydrographic winch was used to collect the sediment samples. Each sample was extracted and cleaned. Residues were detected by electron capture gas chromatography. A range variation in the concentration...

  12. A Numerical Study of Hydrodynamics and Sediment Transport in Fourleague Bay, Louisiana

    Science.gov (United States)

    Hu, K.; Chen, Q. J.; Xu, K.; Bentley, S. J.; WANG, J.

    2017-12-01

    Fourleague Bay is a shallow and vertically well-mixed estuary in south-central Louisiana. This estuary is highly impacted by wind (e.g., cold fronts and tropical storms), river discharge from the Atchafalaya River and tides from the Gulf of Mexico, and is being used as an analog site to study impacts of sediment-diversion restoration strategies in the Mississippi River Delta. In this study, a coupled flow-wave Delft3D model was setup and applied to study hydrodynamics and sediment transport in this area. The model grid size is 1071x631 with a 50-m resolution in the bay. Vegetation is considered by rigid cylinders in both flow and wave modules. The offshore water level boundary conditions were provided by a Gulf-scale Delft3D model. Model parameters, especially for cohesive sediment transport such as settling velocity, erosion rate and critical bottom shear stress, were calibrated using the field observation data during three seasons from May 2015 to March 2016. The modeled water levels, currents, significant wave heights and suspended sediment concentrations agreed fairly well with measurements, which suggests a reasonable model performance. Seasonal variations were analyzed based on different scenarios. A series of numerical experiments were set up to quantify the contributions of different factors, such as river discharge, tides and waves to sediment transport in this area. This model will be further applied to be part of a landscape ecosystem model to test landscape and population change over time with manipulations to sediment delivery. This study was funded by the National Science Foundation (SEES-1427389 and CCF-1539567).

  13. Historical sediment budget and present-day catchment-shoreline coupling at Twofold Bay, southeastern Australia

    Science.gov (United States)

    Tamura, T.; Oliver, T.; Hudson, J.; Woodroffe, C. D.

    2017-12-01

    Considering projected impacts of sea-level rise in the 21st century on sandy shorelines, an understanding of long-term sediment budget for individual beaches or coastal compartments supports assessments of shoreline stability. We examined a low-lying coastal beach-ridge barrier in Twofold Bay using optically stimulated luminescence (OSL) dating , airborne LiDAR, sedimentological analysis and seismic data to assess changes in rates of sediment supply to this shoreline through time. Calculations of barrier volume, Twofold Bay bay-floor sediment volume and estimates of sediment delivery from a proximal river system provide a broad-scale assessment of past-sediment budget. Between ca. 7500 years ago and 1500 years ago, sources of sediment for shoreline progradation at Boydtown were bay-floor sediments either inherited or moved into the embayment during late-stage transgression. Progradation rate between ca. 7500-1500 years ago was 0.16 m/yr with subaerial barrier volume accumulating at 0.46 m3/m/yr. Between ca. 1500 years and present day, the Towamba River to the south has delivered additional sediment to the Boydtown shoreline more than doubling shoreline progradation rate to 0.65 m/yr and subaerial barrier accumulation has risen to 1.83 m3/m/yr. The delivery of fluvial sediment from the Towamba River was restricted to the past ca. 1500 years as prior to this, estuary infilling prevented floods delivering sediments to the bay. This recent historical coupling of river sand supply and shoreline progradation rate implies that anthropogenic modifications to the Towamba River catchment such as river damming, or climatic changes reducing rainfall or runoff, would negatively impact the Boydtown Beach shoreline. Conversely increased rainfall or deforestation may increase sediment discharge due to upstream erosion. The Boydtown shoreline within Twofold Bay may be able to maintain its current position in the coming century if fluvial sediment delivery continues. The fact that

  14. Sedimentation rate in Trombay bay, west coast of India

    International Nuclear Information System (INIS)

    Borkar, M.D.; Pillai, K.C.

    1991-01-01

    The sedimentation rate plays a significant role in the distribution of pollutants discharged into the water bodies. Of the several methods available for determining the sedimentation rate in the shallow water environment, the one based on exponential profile of excess 210 Pb in undisturbed sediment core, has been widely used. Based on this, the sedimentation rate in the Trombay bay ranges between 3 and 4 mm.y -1 . (author). 13 refs

  15. Delaware River and Upper Bay Sediment Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The area of coverage consists of 192 square miles of benthic habitat mapped from 2005 to 2007 in the Delaware River and Upper Delaware Bay. The bottom sediment map...

  16. Concentrations of some elements in the coastal sea sediments. Bays with marinas

    International Nuclear Information System (INIS)

    Obhodas, J.; Kutle, A.; Valkovic, V.

    2006-01-01

    Surface sediments and sediment cores from two bays in the Adriatic sea (Punat Bay and Soline Bay, Croatia) have been analyzed for a number of elements, in particular: Ti, V, Mn, Fe, Cu, Zn, As and Pb, by using XRF. Maps of elemental distribution in surface sediments show increased concentrations for some elements present in antifouling paints (Cu, Zn, Pb) near the service areas in the villages or marinas. Core profiles for these elements were used to evaluate the environmental impact of newly constructed marinas. Source partition indicates the influence of other sources located in near by villages. The critical factor in these considerations was shown to be water exchange with the open sea. (author)

  17. Radionuclides and trace elements in middle Chesapeake Bay sediments

    International Nuclear Information System (INIS)

    Gavrilas, M.

    1988-01-01

    Sediments play an important role in aquatic ecology by serving as a repository for radioactive substances and for soluble chemical pollutants that they may transport over considerable distances and may pass to a higher trophic level by way of bottom-feeding biota. The Chesapeake Bay is a moderately stratified, drowned river valley estuary. The oscillatory flood and ebb of the tidal currents are the most obvious motions in the bay and its tributary estuaries. It is considered that the distribution of most of the pollutants, once diluted by the mixing action of the tidal flow, remains relatively constant for many miles up and down the bay. This paper documents the present status of the radioactivity and of trace elements in sediment samples collected in March 1986 from and extended area around the Calvert Cliffs Nuclear Power Plant

  18. Sediment transport of streams tributary to San Francisco, San Pablo, and Suisun Bays, California, 1909-66

    Science.gov (United States)

    Porterfield, George

    1980-01-01

    A review of historical sedimentation data is presented, results of sediment-data collection for water years 1957-59 are summarized, and long-term sediment-discharge estimates from a preliminary report are updated. Comparison of results based on 3 years of data to those for the 10 water years, 1957-66, provides an indication of the adequacy of the data obtained during the short period to define the long-term relation between sediment transport and streamflow. During 1909-66, sediment was transported to the entire San Francisco Bay system at an average rate of 8.6 million cubic yards per year. The Sacramento and San Joaquin River basins provided about 83% of the sediment inflow to the system annually during 1957-66 and 86% during 1909-66. About 98% of this inflow was measured or estimated at sediment measuring sites. Measured sediment inflow directly to the bays comprised only about 40% of the total discharged by basins directly tributary to the bays. About 90% of the total sediment discharge to the delta and the bays in the San Francisco Bay system thus was determined on the basis of systematic measurements. (USGS)

  19. Temporal and spatial distribution of beryllium-7 in the sediments of Chesapeake Bay

    International Nuclear Information System (INIS)

    Dibb, J.E.; Rice, D.L.

    1989-01-01

    The sediment inventory of 7 Be was determined at six stations in the main stem of Chesapeake Bay nine times between April, 1986, and September, 1987. The inventories ranged from -2 . Comparison to the atmospherically supported 7 Be inventory (range 2-4 dpm cm -2 ) showed significant focusing of 7 Be in the sediments in the zone of the turbidity maximum during the summer, and suggested that the spatial distribution of 7 Be in the lower Bay apparently had a recurrence frequency greater than the sampling frequency in this investigation. The temporal pattern of 7 Be accumulation at the six stations over the first year of this investigation allowed estimation of sedimentation rates, which suggested that the processes governing the distribution of 7 Be in Chesapeake Bay sediments were similar to the processes determining sedimentation patterns over about the past 100 years. (author)

  20. Trace metal contamination in mangrove sediments, Guanabara Bay, Rio de Janeiro, Brazil

    OpenAIRE

    Farias,Cassia O.; Hamacher,Claudia; Wagener,Angela de Luca R.; Campos,Reinaldo C. de; Godoy,José M.

    2007-01-01

    The Guanabara Bay in Rio de Janeiro has undergone profound alterations of its natural environmental conditions. Metal concentration increase in sediments has been reported to be among these alterations. Trace-metal contamination and availability were studied in sediments of 3 mangrove areas of the bay. Cd, Zn, Pb, Ni, Cu and Al concentrations were determined in segments of sediment cores, after treatment with 1 mol L-1 HCl and with concentrated HNO3. Fe and Mn were determined in the leach wit...

  1. Use of excess 210Pb and 228Th to estimate rates of sediment accumulation and bioturbation in Port Phillip Bay, Australia

    International Nuclear Information System (INIS)

    Hancock, G.J.; Hunter, J.R.

    1999-01-01

    Rates of sediment accumulation, sediment mixing and depositional particle fluxes were estimated by use of excess 210 Pb and 228 Th. In central Port Phillip Bay, there was a rapidly mixed surface layer and two layers of different mixing rates at 2-20 cm and 2145 cm depths. When the sediment profiles of excess 210 Pb and 228 Th were combined and diffusive mixing was assumed, the sediment accumulation rate in the 2-20 cm layer was constrained to be -1 . The mixing coefficient in the 2-20 cm layer was 5.0 ± 0.1 cm 2 year -1 . Hence, mixing rather than sedimentation governs the distribution of 210 Pb and 228 Th in the surficial 20 cm. Below 20 cm, the different mixing regime may be due to the dominance of deposit-feeders at these depths. Evidence for bioturbation to a depth of 50 cm was obtained from profiles of excess 210 Pb and 228 Ra deficiency. The mean residence time of particles in the central bay water column was 10 ± 2 days (a normalized depositional particle flux of 0.16 ± 0.02 g cm -2 year -1 ). This flux is three times the upper estimate of the sediment accumulation rate, indicating that most of the suspended particulate matter in the water column is resuspended bottom sediment. Copyright (1997) CSIRO Publishing

  2. Trends in Accretion Rates of Riverine Sediments in a Distal Bay and Wetlands Using 7-Beryllium as a Tracer: Fourleague Bay, Louisiana.

    Science.gov (United States)

    Restreppo, G. A.; Bentley, S. J.; Wang, J.; Xu, K.

    2017-12-01

    To combat land loss along the Mississippi River Delta, Louisiana has launched a historic campaign to sustain and regrow coastal lands using, in part, sediment diversions. Previous research has focused primarily on sand sized sediment load, which is usually deposited proximal to a river's delta or a diversion's outlet. Fine sediments constitute the majority of sediment load in the Mississippi, but are under-studied with respect to dispersal processes, particularly in terms of sediment supply to distal deltaic bays and wetlands. The Atchafalaya River and associated wetlands serve as prime study areas for this purpose. Bimonthly time-series push cores were collected from May 2015 to May 2016 along ten sites within Fourleague Bay, Louisiana. Fourleague Bay has remained stable against the deteriorative effects of relative sea level rise, standing out along Louisiana's declining coastline. Of the ten field sites, five are located across a longitudinal transect in the middle bay, while the other five are located in adjacent marshes. All sites fall within 10 to 30 km of the Atchafalaya Delta, extending south towards the Gulf of Mexico. Cores were extruded in 2 cm intervals, dried, ground, and analyzed via gamma spectrometry for the presence of 7Be. Inventories of 7Be were then calculated and used to determine daily mass accretion rate (MAR) over twelve months. Average MAR values for the bay and the marshes are compared with Atchafalaya River discharge, wind data, and atmospheric pressure through the year of sampling. Peak marsh MAR, 0.88 ± 0.20 kg m-2 d-1, occurs just after historically high river discharge. Peak bay MAR, 1.2 ± 0.67 kg m-2 d-1, occurs during seasonal low river discharge and calm winds. Average bay and marsh MARs have a moderate to strong, negative correlation when compared. Results indicate sediment bypass of the bay floor during periods of moderate to high river discharge, entering the marshes directly when inundation occurs and enhanced by the passage

  3. Chlorinated hydrocarbon pesticides and polychlorinated biphenyls in sediment cores from San Francisco Bay

    Science.gov (United States)

    Venkatesan, M.I.; De Leon, R. P.; VanGeen, A.; Luoma, S.N.

    1999-01-01

    Sediment cores of known chronology from Richardson and San Pablo Bays in San Francisco Bay, CA, were analyzed for a suite of chlorinated hydrocarbon pesticides and polychlorinated biphenyls to reconstruct a historic record of inputs. Total DDTs (DDT = 2,4'- and 4,4'-dichlorodiphenyltrichloroethane and the metabolites, 2,4'- and 4,4'-DDE, -DDD) range in concentration from 4-21 ng/g and constitute a major fraction (> 84%) of the total pesticides in the top 70 cm of Richardson Bay sediment. A subsurface maximum corresponds to a peak deposition date of 1969-1974. The first measurable DDT levels are found in sediment deposited in the late 1930's. The higher DDT inventory in the San Pablo relative to the Richardson Bay core probably reflects the greater proximity of San Pablo Bay to agricultural activities in the watershed of the Sacramento and San Joaquin rivers. Total polychlorinated biphenyls (PCBs) occur at comparable levels in the two Bays (inventories in San Pablo Bay are about a factor of four higher in the last four decades than in Richardson Bay, suggesting a distribution of inputs not as strongly weighed towards the upper reaches of the estuary as DDTs. The shallower subsurface maximum in PCBs compared to DDT in the San Pablo Bay core is consistent with the imposition of drastic source control measures four these constituents in 1970 and 1977 respectively. The observed decline in DDT and PCB levels towards the surface of both cores is consistent with a dramatic drop in the input of these pollutants once the effect of sediment resuspension and mixing is taken into account.

  4. Diurnal variation in rates of calcification and carbonate sediment dissolution in Florida Bay

    Science.gov (United States)

    Yates, K.K.; Halley, R.B.

    2006-01-01

    Water quality and circulation in Florida Bay (a shallow, subtropical estuary in south Florida) are highly dependent upon the development and evolution of carbonate mud banks distributed throughout the Bay. Predicting the effect of natural and anthropogenic perturbations on carbonate sedimentation requires an understanding of annual, seasonal, and daily variations in the biogenic and inorganic processes affecting carbonate sediment precipitation and dissolution. In this study, net calcification rates were measured over diurnal cycles on 27 d during summer and winter from 1999 to 2003 on mud banks and four representative substrate types located within basins between mud banks. Substrate types that were measured in basins include seagrass beds of sparse and intermediate density Thalassia sp., mud bottom, and hard bottom communities. Changes in total alkalinity were used as a proxy for calcification and dissolution. On 22 d (81%), diurnal variation in rates of net calcification was observed. The highest rates of net carbonate sediment production (or lowest rates of net dissolution) generally occurred during daylight hours and ranged from 2.900 to -0.410 g CaCO3 m-2 d-1. The lowest rates of carbonate sediment production (or net sediment dissolution) occurred at night and ranged from 0.210 to -1.900 g CaCO3 m -2 night-1. During typical diurnal cycles, dissolution during the night consumed an average of 29% of sediment produced during the day on banks and 68% of sediment produced during the day in basins. Net sediment dissolution also occurred during daylight, but only when there was total cloud cover, high turbidity, or hypersalinity. Diurnal variation in calcification and dissolution in surface waters and surface sediments of Florida Bay is linked to cycling of carbon dioxide through photosynthesis and respiration. Estimation of long-term sediment accumulation rates from diurnal rates of carbonate sediment production measured in this study indicates an overall average

  5. Algae Reefs in Shark Bay, Western Australia, Australia

    Science.gov (United States)

    1990-01-01

    Numerous algae reefs are seen in Shark Bay, Western Australia, Australia (26.0S, 113.5E) especially in the southern portions of the bay. The south end is more saline because tidal flow in and out of the bay is restricted by sediment deposited at the north and central end of the bay opposite the mouth of the Wooramel River. This extremely arid region produces little sediment runoff so that the waters are very clear, saline and rich in algae.

  6. Coastal currents and mass transport of surface sediments over the shelf regions of Monterey Bay, California

    Science.gov (United States)

    Wolf, S.C.

    1970-01-01

    In Monterey Bay, the highest concentrations of medium and fine sands occur nearshore between ten and thirty fathoms. Silt and clay accumulate in greater depths. Contours of median diameter roughly parallel the isobaths. Fine-grained materials are supplied to the bay region from erosion of cliffs which partly surround Monterey Bay, from sediment laden river discharge, and from continual reworking of widespread Pleistocene and Recent sea floor sediments. These sediments in turn are picked up by coastal currents and distributed over the shelf regions by present day current regimes. Studies of bottom currents over the shelf regions and in Monterey Canyon have revealed patterns which vary with seasonal changes. Current patterns during August and September exhibit remarkable symmetry about the axis of Monterey Submarine Canyon. Central Shelf currents north and south of Monterey Canyon flowed northwest at an average rate of 0.2 knots and south at 0.3 knots respectively. On the North Shelf between January and March currents flowed east to southeast at 0.3-0.5 knots with mirror image patterns above the South Shelf during the same period. Irregular current flow in the canyon indicates a complex current structure with frequent shifts in counterclockwise and clockwise direction over very short periods of time. Bottom topography of the canyon complex often causes localization of canyon currents. One particular observation at a depth of 51 fathoms indicated up-canyon flow at a rate of 0.2 knots. Most of the observed currents are related to seasonal variations, upwelling, ocean swell patterns, and to changes in the California and Davidson currents. Changes in current regimes are reflected in the patterns of sediment distribution and transport. Sediment transport is chiefly parallel to the isobaths, particularly on the North and South Shelf regions. Complex dispersal patterns are observed near Monterey Canyon and Moss Landing Harbor jetties. Longshore currents move sediments

  7. Delaware Bay, Delaware Sediment Distribution 2003 to 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The area of coverage consists of 38 square miles of benthic habitat mapped from 2003 to 2004 along the middle to lower Delaware Bay Coast. The bottom sediment map...

  8. The Kara Bogaz Gol Bay, Lake Issyk Kul and Aral Sea sediments as archives of climate change in the Aral-Caspian catchment basin

    International Nuclear Information System (INIS)

    Ferronsky, V.I.; Brezgunov, V.S.; Vlasova, L.S.; Karpychev, Y.A.; Polyakov, V.A.; Bobkov, A.F.; Romanovsky, V.V.; Johnson, T.; Ricketts, D.; Rasmussen, K.

    2002-01-01

    A 5-m long core of bottom sediments from the Kara Bogaz Gol Bay of the Caspian Sea, 4- m and 2-m cores from the Issyk Kul Lake of the Thian Shan Mountains, and a 4-m core from the Aral Sea were examined for evidence of climatic and environmental changes in the catchment basin of the Central Asia Region. The distribution of 18 O and 13 C in the bulk carbonates, 2 H in the pore water, radiocarbon age, oxygen and hydrogen isotopes in the lake water, abundance of CaCO 3 , MgCO 3 , and the basic salt ions of Na + , K + , Cl - , SO 4 2- in the cores were measured. The isotope and hydrogeochemical data of the Kara Bogaz Gol Bay sediments prove a historical scenario for the basin which suggests that fresh water has been discharged to the Caspian Sea during the Bay's humid episode across the Central Asia Region (∼ 9 Ka BP). Isotope and geochemical evidence indicate that the sedimentation of the upper core segment has taken place during the last ∼2.2 Ka BP in the environment of sea water recharged from the Central Caspian Basin. The period of between 4.3 and 6 Ka BP, which relates to the core depth interval of between 170 cm and 260 cm, demonstrates the most dramatic change in the sedimentation rate in the Issyk Kul Lake. It means that active melting of the mountain glaciers and warming of climate has happened just in this period. The swamp plant peat layers at depths of 230 cm and 130 cm indicate that during 3.5-3.7 Ka BP and 1.6-1.8 Ka BP the Aral Sea dried and broke up into a number of lakes and swamps. Sediment cores taken from the bottom of the Kara Bogaz Gol Bay, Lake Issyk Kul and Aral Sea show periodic rise and fall in water levels during the last ∼10 000 years. Two peat layers within the sediment core of the Aral Sea and dated at 1.6-1.8 Ka BP and 3.5-3.7 Ka BP demonstrate that this reservoir also periodically dried. (author)

  9. The sediment budget of an urban coastal lagoon (Jamaica Bay, NY) determined using 234Th and 210Pb

    Science.gov (United States)

    Renfro, Alisha A.; Cochran, J. Kirk; Hirschberg, David J.; Bokuniewicz, Henry J.; Goodbred, Steven L.

    2016-10-01

    The sediment budget of Jamaica Bay (New York, USA) has been determined using the natural particle-reactive radionuclides 234Th and 210Pb. Inventories of excess thorium-234 (234Thxs, half-life = 24.1 d) were measured in bottom sediments of the Bay during four cruises from September 2004 to July 2006. The mean bay-wide inventory for the four sampling periods ranged from 3.5 to 5.0 dpm cm-2, four to six times that expected from 234Th production in the overlying water column. The presence of dissolved 234Th and a high specific activity of 234Thxs on particles at the bay inlet (∼30 dpm g-1) indicated that both dissolved and particulate 234Th could be imported into the bay from the ocean. Based on these observations, a mass balance of 234Th yields an annual input of ∼39 ± 14 × 1010 g sediment into the bay. Mass accumulation rates determined from profiles of excess 210Pb (half-life = 22.3 y) in sediment cores require annual sediment import of 7.4 ± 4.5 × 1010 g. Both radionuclides indicate that there is considerable marine-derived sediment import to Jamaica Bay, consistent with earlier work using 210Pb. Such sediment input may be important in sustaining longer-term accretion rates of salt marshes in the bay.

  10. Estimating sediment accumulation rates in Manila Bay, a marine pollution hot spot in the Seas of East Asia.

    Science.gov (United States)

    Sta Maria, E J; Siringan, F P; Bulos, A dM; Sombrito, E Z

    2009-01-01

    The GEF/UNDP/IMO/PEMSEA project identifies Manila Bay as among the marine pollution hot spots in the Seas of East Asia. (210)Pb dating of its sediment can provide a historical perspective of its pollution loading. However, the validity of (210)Pb dating in a complex dynamic coastal system of Manila Bay may come into question. Land-based sediment input can be high and physical and biological processes can possibly disturb the sediment layers. In this report, the (210)Pb profiles of sediment cores from different parts of the bay are presented. The linear sedimentation rates are shown to be higher in the recent past and are also variable across the bay. The largest change in sedimentation rate, coincided with the occurrence of a volcanic eruption in 1991 and is shown by applying a variant of the CIC model in sedimentation rate calculations. The data suggest that (210)Pb dating can be useful in estimating relative magnitudes of sedimentation rates, even in a complex dynamic coastal system like Manila Bay.

  11. A comparative study on the heavy metals distribution in sediment profiles from Ribeira and Sepetiba Bays, RJ - Brazil

    International Nuclear Information System (INIS)

    Carvalho, Franciane; Tadeu Lopes, Ricardo

    2008-01-01

    A set of sediment cores was sampled at Sepetiba bay and Ribeira bay, in the Rio de Janeiro State, Brazil. Sedimentation rates were determined by geochronological evaluation of sediments by Pb-210. In Ribeira Bay, the sedimentation rate increases from the sampling point RB1 (0.15 cm y -1 ), in the inner part of the bay, towards the sampling point RB4, close to its entrance (0.34 cm y -1 ). For Sepetiba Bay, two well-defined sedimentation rates were observed, a lower value of 0.3 cm y -1 for the period before the 1960s, and a more recent rate of 0.75 cm y -1 . These measurements are consistent to the construction of the Santa Cecilia impoundment in 1955, which brings water from the Paraiba do Sul Basin into the Guandu River, increasing the river flow from 20 m 3 s -1 to 160 m 3 s -1 . The metal concentrations were determined by ICP-MS. It could be seen that the reliability of Ribeira bay as a reference database for metal concentrations in the neighboring Sepetiba Bay is valid for a specific set of elements, such as K, Ti, Mn, Zn, Ga, Rb and Sr, but not for V, Cr and Cd. Applying to the mean elemental concentration, of the upper contaminated 45 cm sediment layer, and to the elemental concentration of the deepest analysed sediment layer a normalization to iron, a double ratio was calculated and it was concluded that the Sepetiba Bay sediments are, particularly, contaminated with Cr, may be, from a leather tanning plant existing in this region and Cd and Zn from the former Inga Metais. The overall results can be used to confirm the reliability of the utilization of Ribeira bay as a reference database to the evaluation of metal pollution profile of Sepetiba bay, by an intercomparison methodology. (author)

  12. Superficial distribution of aromatic compounds and geomicrobiology of sediments from Suruí Mangrove, Guanabara Bay, RJ, Brazil

    OpenAIRE

    Fontana,Luiz F.; Silva,Frederico S. da; Figueiredo,Natália G. de; Brum,Daniel M.; Netto,Annibal D. Pereira; Gigueiredo Junior,Alberto G. de; Crapez,Mirian A.C.

    2010-01-01

    The distribution of selected aromatic compounds and microbiology were assessed in superficial sediments from Suruí Mangrove, Guanabara Bay. Samples were collected at 23 stations, and particle size, organic matter, aromatic compounds, microbiology activity, biopolymers, and topography were determined. The concentration of aromatic compounds was distributed in patches over the entire mangrove, and their highest total concentration was determinated in the mangrove's central area. Particle size d...

  13. Sediment biogeochemistry in an East African mangrove forest (Gazi Bay, Kenya)

    NARCIS (Netherlands)

    Middelburg, J.J.; Nieuwenhuize, J.; Slim, F.J.; Ohowa, B.

    1996-01-01

    The biogeochemistry of mangrove sediments was investigated in several mangrove forest communities in Gazi Bay, a coastal lagoon in Kenya, Africa. Carbon dioxide fluxes, sediment median grain sizes, sedimentary organic carbon, nitrogen and phosphorus contents and pore-water characteristics (ammonium,

  14. Long-term impacts due to sediment supply changes towards the San Francisco Bay-Delta system

    Science.gov (United States)

    Achete, F.; Van der Wegen, M. V.; Jaffe, B. E.

    2012-12-01

    The Sacramento-San Joaquin Delta and Watershed is the main source of fresh water and sediment to San Francisco Bay. Mid 19th century hydraulic mining in the catchment caused an excessive supply of sediment. After mining activities stopped, in the first part of the 20th century several hydraulic structures were built deviating fresh water and trapping sediment upstream. The main purpose of most of these structures is water storage for irrigation and/or water supply Wright and Schoellhamer (2004) show that from 1957 to 2001 the sediment load carried to San Francisco Bay has decreased by about one half. The lack of sediments may lead to a different erosion/deposition pattern in the Bay-Delta system causing problems like mud flat erosion, shift in navigation channel, land subsidence and changing habitat for endemic species. The objective of this work is to identify and quantify morphological shifts in the Bay-Delta system due to variation in fresh water and sediment supply. In this study, we couple the Delta and Bay in a unique model network (the Delta-Bay model). This coupling allows tracking of sediment from Sacramento via the Delta and Bay and through the Golden Gate, making it possible to identify erosion and deposition areas. The numerical model applied is an unstructured, process-based model (D-Flow Flexible Mesh developed by Deltares). It simulates the hydrodynamics and morphodynamics of the area on a detailed, 64000-node mesh (10-200m mesh length scale) on a timescale of minutes. The morphological impact is assessed for multiple scenarios with different input of sediment and fresh water. A statistical analysis is performed to account for uncertainty of model parameters and climate change impacts. The fresh water discharge already has a strong natural seasonal and inter-annual variation. The human impact by foreseen different water pumping strategies due to the peripheral canal will be considered. Jaffe et al. (2007) has shown that substantial morphological

  15. Study of recent sediment accumulation rate using 210Pb around Mumbai Harbor Bay

    International Nuclear Information System (INIS)

    Chaudhury, Moushumi D.; Pulhani, Vandana; Jha, S.K.; Tripathi, R.M.

    2016-01-01

    The study of the coastal marine sediment of Mumbai harbor bay (MHB) provides a significant insight of the stress due to unprecedented increase of anthropogenic activities in and around the bay and climatic changes. This encourages archiving the sediments for characterizing the depositional environment of water system by examining the sediment accumulation rate (SAR) to understand thc annual deposition of chemical contaminants. The study of SAR evaluates the fate and potential effects of chemical contaminants which when discharged into aquatic environment quickly become attached to sediment particles at different exchange sites. The rate of sediment accumulation has a significant impact on many geochemical processes; it is also vital for the functioning of benthic organisms in this environment, particularly the seabed fauna. SAR is calculated from sedimentation rate, bulk density and porosity

  16. Distribution of trace elements in the coastal sea sediments of Maslinica Bay, Croatia

    Science.gov (United States)

    Mikulic, Nenad; Orescanin, Visnja; Elez, Loris; Pavicic, Ljiljana; Pezelj, Durdica; Lovrencic, Ivanka; Lulic, Stipe

    2008-02-01

    Spatial distributions of trace elements in the coastal sea sediments and water of Maslinica Bay (Southern Adriatic), Croatia and possible changes in marine flora and foraminifera communities due to pollution were investigated. Macro, micro and trace elements’ distributions in five granulometric fractions were determined for each sediment sample. Bulk sediment samples were also subjected to leaching tests. Elemental concentrations in sediments, sediment extracts and seawater were measured by source excited energy dispersive X-ray fluorescence (EDXRF). Concentrations of the elements Cr, Cu, Zn, and Pb in bulk sediment samples taken in the Maslinica Bay were from 2.1 to over six times enriched when compared with the background level determined for coarse grained carbonate sediments. A low degree of trace elements leaching determined for bulk sediments pointed to strong bonding of trace elements to sediment mineral phases. The analyses of marine flora pointed to higher eutrophication, which disturbs the balance between communities and natural habitats.

  17. Hurricane-induced Sediment Transport and Morphological Change in Jamaica Bay, New York

    Science.gov (United States)

    Hu, K.; Chen, Q. J.

    2016-02-01

    Jamaica Bay is located in Brooklyn and Queens, New York on the western end of the south shore of the Long Island land mass. It experienced a conversion of more than 60% of the vegetated salt-marsh islands to intertidal and subtidal mudflats. Hurricanes and nor'easters are among the important driving forces that reshape coastal landscape quickly and affect wetland sustainability. Wetland protection and restoration need a better understanding of hydrodynamics and sediment transport in this area, especially under extreme weather conditions. Hurricane Sandy, which made landfall along east coast on October 30, 2012, provides a critical opportunity for studying the impacts of hurricanes on sedimentation, erosion and morphological changes in Jamaica Bay and salt marsh islands. The Delft3D model suit was applied to model hydrodynamics and sediment transport in Jamaica Bay and salt marsh islands. Three domains were set up for nesting computation. The local domain covering the bay and salt marshes has a resolution of 10 m. The wave module was online coupled with the flow module. Vegetation effects were considered as a large number of rigid cylinders by a sub-module in Delft3D. Parameters in sediment transport and morphological change were carefully chosen and calibrated. Prior- and post-Sandy Surface Elevation Table (SET)/accretion data including mark horizon (short-term) and 137Cs and 210Pb (long-term) at salt marsh islands in Jamaica Bay were used for model validation. Model results indicate that waves played an important role in hurricane-induced morphological change in Jamaica Bay and wetlands. In addition, numerical experiments were carried out to investigate the impacts of hypothetic hurricanes. This study has been supported by the U.S. Geological Survey Hurricane Sandy Disaster Recovery Act Funds.

  18. Mapping sediment contamination and toxicity in Winter Quarters Bay, McMurdo Station, Antarctica.

    Science.gov (United States)

    Crockett, Alan B; White, Gregory J

    2003-07-01

    Winter Quarters Bay (WQB) is a small embayment located adjacent to McMurdo Station, the largest research base in Antarctica. The bay is approximately 250 m wide and long, with a maximum depth of 33 m. Historically, trash from the McMurdo Station was piled on the steep shoreline of WQB, doused with fuel and ignited. That practice has ceased, and the adjacent land area has been regraded to cover the residual waste. The bottom of WQB remains littered with drums, equipment, tanks, tires, cables, and other objects, especially the southeastern side of the bay where dumping took place. Sediments are contaminated with PCBs, metals, and hydrocarbon fuels. The objectives of this study were to map the distribution of organic contaminants in WQB, assess the toxicity of WQB sediments using a simple microbial test, and determine correlations between toxicity and contaminant levels. The study suggests that adverse ecological effects have occurred from one or more of the contaminants found in WQB but the source of the toxic impacts to bay sediments remains unknown. Whole sediment toxicity was only correlated with oil-equivalent while solvent extracts of sediments were correlated with PAHs and oil-equivalent. The authors recommend that an integrated research plan be developed that focuses on determining what additional information is needed to make informed decisions on possible remediation of WQB.

  19. Late Quaternary sedimentation in eastern Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S; Mascarenhas, A; Paropkari, A; Rao, Ch.M.

    This study presents variations in various size measures, calcium carbonate, organic carbon, clay mineralogy and major and trace elements in a core (5.40 m long, 2713 m depth) from the eastern Bay of Bengal. On a CM diagram, the sediments of the core...

  20. Radiocarbon dating, chronologic framework, and changes in accumulation rates of holocene estuarine sediments from Chesapeake Bay

    Science.gov (United States)

    Colman, Steven M.; Baucom, P.C.; Bratton, J.F.; Cronin, T. M.; McGeehin, J.P.; Willard, D.; Zimmerman, A.R.; Vogt, P.R.

    2002-01-01

    Rapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelarator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different components of the sediments show that total organic carbon ages are largely unreliable, because much of the carbon (including coal) has been transported to the bay from upstream sources and is older than sediments in which it was deposited. Mollusk shells (clams, oysters) and foraminifera appear to give reliable results, although reworking and burrowing are potential problems. Analyses of museum specimens collected alive before atmospheric nuclear testing suggest that the standard reservoir correction for marine samples is appropriate for middle to lower Chesapeake Bay. The biogenic carbonate radiocarbon ages are compatible with 210 Pb and 137 Cs data and pollen stratigraphy from the same sites. Post-settlement changes in sediment transport and accumulation is an important environmental issue in many estuaries, including the Chesapeake. Our data show that large variations in sediment mass accumulation rates occur among sites. At shallow water sites, local factors seem to control changes in accumulation rates with time. Our two relatively deep-water sites in the axial channel of the bay have different long-term average accumulation rates, but the history of sediment accumulation at these sites appears to reflect overall conditions in the bay. Mass accumulation rates at the two deep-water sites rapidly increased by about fourfold coincident with widespread land clearance for agriculture in the Chesapeake watershed.

  1. Bank-derived material dominates fluvial sediment in a suburban Chesapeake Bay watershed

    Science.gov (United States)

    Cashman, M. J.; Gellis, A.; Gorman-Sanisaca, L.; Noe, G. B.; Cogliandro, V.; Baker, A.

    2017-12-01

    Excess fine sediment is a leading cause of ecological degradation within the Chesapeake Bay watershed. The Piedmont physiographic province, which includes parts of the Washington, D.C. metro area, has the highest sediment yields in the Chesapeake Bay. In order to effectively employ sediment mitigation measures, it is necessary to identify and quantify the contributions of sediments sources within rapidly urbanizing areas in the Piedmont. This sediment fingerprinting study examines the inputs of various sediment sources to Upper Difficult Run (14.2 km2; 22.6% impervious surface), an urbanized watershed in Fairfax County, Virginia. A source sediment library was constructed from collections of stream bank material, forest soils, and road dust from across the watershed. Target fluvial sediments were collected from fine channel margin deposits and from suspended sediment using an autosampler during 16 storm events from 2008 - 2012. Apportionment of the target samples to the source sediments was performed using Sed_SAT, a publically available toolkit for sediment fingerprinting. Bed sediment was found to be dominated by stream bank sources (mean: 96%), with minor contributions from forest (4%) and no detectable contribution from roads (0%). Suspended fine sediments were also found to predominantly originate from stream bank sources (SSC-weighted mean: 91%), with minor contributions from roads (8%), and negligible contributions from forests (1%). Stream bank sources dominated at all discharges, with the greatest contributions from overland sources found only at low discharges. On the rising limb of the hydrograph and at peak flow, sediment concentrations increased due to increasing contributions of bank material rather than surface erosion caused by overland flow. Results demonstrate that stream bank erosion is responsible for the vast majority of fine sediment occurring in this suburban basin of the Chesapeake Bay watershed. This is likely a consequence of storm

  2. Mercury pollution in sediments, benthic organisms and inshore fishes of Haifa Bay, Israel

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, H; Krumgalz, B S; Cohen, Y

    1984-01-01

    Total mercury concentrations were determined in surficial sediments, eleven species of benthic organisms and six species of fish from Haifa Bay, Israel. The results show that essentially all of the shallow water zone of the Bay receives anthropogenic mercury. A mercury-cell chlor-alkali plant was identified as the source of pollution. Surficial sediments in vicinity of the plant, containing up to 0.99 micro-g Hg/g dry weight, were up to 157 times enriched in mercury relative to an unpolluted area. Mercury levels in the benthic organisms reflected the levels in the sediments. Maximal concentrations reaching 38.7 and 18.2 micro-g Hg/g dry weight were found in the carnivorous gastropod mollusks Arcularia circumcinta and Arcularia gibbosula, respectively. In all fish species, specimens caught in Haifa Bay had higher mercury concentrations in the muscle tissue than specimens caught south of the Bay. A maximal value of 1.66 micro-g Hg/g wet weight was recorded in Diplodus sargus. 17 references, 3 figures, 3 tables.

  3. Rapid sedimentation of iron oxyhydroxides in an active hydrothermal shallow semi-enclosed bay at Satsuma Iwo-Jima Island, Kagoshima, Japan

    Science.gov (United States)

    Kiyokawa, Shoichi; Ueshiba, Takuya

    2015-04-01

    Hydrothermal activity is common in the fishing port of Nagahama Bay, a small semi-enclosed bay located on the southwest coast of Satsuma Iwo-Jima Island (38 km south of Kyushu Island, Japan). The bay contains red-brown iron oxyhydroxides and thick deposits of sediment. In this work, the high concentration and sedimentation rates of oxyhydroxide in this bay were studied and the sedimentary history was reconstructed. Since dredging work in 1998, a thickness of 1.0-1.5 m of iron oxyhydroxide-rich sediments has accumulated on the floor of the bay. To estimate the volume of iron oxyhydroxide sediments and the amount discharged from hydrothermal vents, sediment traps were operated for several years and 13 sedimentary core samples were collected to reconstruct the 10-year sedimentary history of Nagahama Bay. To confirm the timing of sedimentary events, the core data were compared with meteorological records obtained on the island, and the ages of characteristic key beds were thus identified. The sedimentation rate of iron oxyhydroxide mud was calculated, after correcting for sediment input from other sources. The sediments in the 13 cores from Nagahama Bay consist mainly of iron oxyhydroxide mud, three thick tephra beds, and a topmost thick sandy mud bed. Heavy rainfall events in 2000, 2001, 2002, and 2004-2005 coincide with tephra beds, which were reworked from Iwo-Dake ash deposits to form tephra-rich sediment. Strong typhoon events with gigantic waves transported outer-ocean-floor sediments and supplied quartz, cristobalite, tridymite, and albite sands to Nagahama Bay. These materials were redeposited together with bay sediments as the sandy mud bed. Based on the results from the sediment traps and cores, it is estimated that the iron oxyhydroxide mud accumulated in the bay at the relatively rapid rate of 33.3 cm/year (from traps) and 2.8-4.9 cm/year (from cores). The pore water contents within the sediment trap and core sediments are 73%-82% and 47%-67%, respectively

  4. Characterization of Dredged Sediments from Santander Bay

    International Nuclear Information System (INIS)

    Cortes, M.; Ibanez, R.; Viguri, J.R.; Irabien, A.

    1999-01-01

    The purpose of this study is the physico- chemical characterisation of Santander Bay (North Spain) inter-tidal sediments, with the determination of levels of selected organic compounds pollution. A sampling strategy has been developed based on characteristic parameters of the study. The physico-chemical seasonal characterisation of sediments has been performed by determination of waster content, Ph, density, humidity, lost on ignition (LOI), particle size distribution, and chemical analysis of three categories of organic compounds (VOCs,EOX and PAHs) selected for its ubiquity, persistence and high potential of environmental hazard. The EOX analysis give a picture of the total load of organo halogen compounds in the estuarine area and the VOC and ph values obtained, allow the characterization of sediments in two areas in function of the closeness to the urban and industrial activities

  5. Shifting shoals and shattered rocks : How man has transformed the floor of west-central San Francisco Bay

    Science.gov (United States)

    Chin, John L.; Wong, Florence L.; Carlson, Paul R.

    2004-01-01

    subembayments--north bay (San Pablo and Suisun Bays), central bay, and south bay--each characterized by a central area of open water surrounded by intertidal mudflats and marshes. Central bay includes Alcatraz and Angel Islands and also a number of submerged bedrock knobs that protrude through the sediment of the bay floor and rise to within about 40 feet (12 m) of the water surface. The most prominent of these are Harding, Shag, Arch, and Blossom Rocks. These rocks have been lowered by blasting several times in the past, but they remain a potential hazard to shipping because newer cargo vessels are designed with increasingly deeper drafts. Central bay's location adjacent to two major population and commerce centers, San Francisco and Oakland, subjects it to greater human influences than less developed parts of the estuary. The western part of central San Francisco Bay is adjacent to the Golden Gate, the estuary's outlet to the Pacific Ocean. The changing submarine topography of the west-central bay, as well as its geology, form the main focus of this book.

  6. Acute and chronic toxicity of sediment samples from Guanabara Bay (RJ) during the rainy period

    OpenAIRE

    Maranho,Luciane Alves; Abreu,Ilene Matanó; Santelli,Ricardo Erthal; Cordeiro,Renato Campelo; Soares-Gomes,Abílio; Moreira,Lucas Buruaem; Morais,Rodofley Davino; Abessa,Denis Moledo de Sousa

    2010-01-01

    Guanabara Bay is a marine-estuarine environment of high ecological and socio-economic importance, subject to a variety of environmental impacts. Sediment is the eventual repository for most substances introduced into water bodies and may, therefore, provide an integrated measure of the environmental quality, which can be assessed by many different approaches. In this project, the quality of sediments from Guanabara Bay was evaluated by the ecotoxicological approach: whole-sediment toxicity te...

  7. Improving Sediment Transport Prediction by Assimilating Satellite Images in a Tidal Bay Model of Hong Kong

    Directory of Open Access Journals (Sweden)

    Peng Zhang

    2014-03-01

    Full Text Available Numerical models being one of the major tools for sediment dynamic studies in complex coastal waters are now benefitting from remote sensing images that are easily available for model inputs. The present study explored various methods of integrating remote sensing ocean color data into a numerical model to improve sediment transport prediction in a tide-dominated bay in Hong Kong, Deep Bay. Two sea surface sediment datasets delineated from satellite images from the Moderate Resolution Imaging Spectra-radiometer (MODIS were assimilated into a coastal ocean model of the bay for one tidal cycle. It was found that remote sensing sediment information enhanced the sediment transport model ability by validating the model results with in situ measurements. Model results showed that root mean square errors of forecast sediment both at the surface layer and the vertical layers from the model with satellite sediment assimilation are reduced by at least 36% over the model without assimilation.

  8. Assessment of Marine Pollution in İzmir Bay: Heavy Metal and Organic Compound Concentrations in Surficial Sediments

    OpenAIRE

    AKSU, Ali Engin

    2014-01-01

    The extent of marine pollution in İzmir Bay is investigated using inorganic and organic geochemical data from surface sediments. The concentrations of 42 elements in 84 samples established that surface sediments in Inner İzmir Bay display significant enrichments in Ag, As, Cd, Cr, Cu, Hg, Mo, P, Pb, Sb, Sn, V, and Zn, associated with notably high concentrations of total organic carbon and sulphur. Organic geochemical data in 14 samples from Inner İzmir Bay showed that these sediments...

  9. Evaluation of older bay mud sediment from Richmond Harbor, California

    Energy Technology Data Exchange (ETDEWEB)

    Pinza, M.R.; Mayhew, H.L.; Word, J.Q.

    1996-09-01

    The older, bay mud (OBM) unit predates modem man and could act as a barrier to the downward transport of contaminants from the younger bay mud (YBM) because of its hard-packed consistency. However, its chemical and biological nature have not been well characterized. Battelle/Marine Sciences Laboratory (MSL) conducted three independent studies of OBM sediment in January 1993, January 1994, and October 1994. These studies evaluated potential chemical contamination and biological effects of OBM that could occur as a result of dredging and disposal activities. These evaluations were performed by conducting chemical analysis, solid-phase toxicity tests, suspended- particulate-phase (SPP) toxicity tests, and bioaccumulation tests on the OBM sediment. If the sediment chemistry and toxicity results showed no or minimal contamination and toxicological responses, then either the OBM could be left exposed in Richmond Harbor after dredging the YBM without leaving a source of contamination, or if the project depths necessitate, the OBM would be acceptable for disposal at an appropriate disposal site.

  10. Transport and accumulation of radionuclides in the marine sediment of Urazoko Bay

    International Nuclear Information System (INIS)

    Nagaya, Yutaka; Nakamura, Kiyoshi

    1976-01-01

    Concentrations of 60 Co and other radionuclides in surface sediment samples were investigated in and around Urazoko Bay, Fukui Prefecture, where a nuclear power plant has been operating since 1969 and the radioactive waste effluent has been released into the sea. The main source of 90 Sr and 137 Cs was recognized to be radioactive fallout from nuclear explosions, whereas 60 Co was considered to originate from the nuclear power reactor. For evaluating radioactive pollution characteristics of the sea bottom, the behaviour of 60 Co was investigated using the 137 Cs concentration as an indicator of the radionuclide sorption capability or accumulation capability of the sediment. No seasonal variation was observed in the distribution pattern of the 60 Co/ 137 Cs ratio and the retention of the heavy initial discharge in 1969 is considered to dominate the radionuclide level in the sediment. The 60 Co contamination in the sediment, expressed as the 60 Co/ 137 Cs ratio, in this narrow and semi-closed bay was found to vary according to a simple exponential function of the distance from the discharge outlet. It was found that the contamination is spreading out gradually from Urazoko Bay to outer regions. Also the correlation between the amount of discharged radioactive waste and the variation of the 60 Co level in the sediment was investigated. (auth.)

  11. Spatial variation in sediment-water exchange of phosphorus in Florida Bay: AMP as a model organic compound.

    Science.gov (United States)

    Huang, Xiao-Lan; Zhang, Jia-Zhong

    2010-10-15

    Dissolved organic phosphorus (DOP) has been recognized as dominant components in total dissolved phosphorus (TDP) pools in many coastal waters, and its exchange between sediment and water is an important process in biogeochemical cycle of phosphorus. Adenosine monophosphate (AMP) was employed as a model DOP compound to simulate phosphorus exchange across sediment-water interface in Florida Bay. The sorption data from 40 stations were fitted to a modified Freundlich equation and provided a detailed spatial distribution both of the sediment's zero equilibrium phosphorus concentration (EPC(0-T)) and of the distribution coefficient (K(d-T)) with respect to TDP. The K(d-T) was found to be a function of the index of phosphorus saturation (IPS), a molar ratio of the surface reactive phosphorus to the surface reactive iron oxide content in the sediment, across the entire bay. However, the EPC(0-T) was found to correlate to the contents of phosphorus in the eastern bay only. Sediment in the western bay might act as a source of the phosphorus in the exchange process due to their high EPC(0-T) and low K(d-T), whereas sediments in the eastern bay might act as a sink because of their low EPC(0-T) and high K(d-T). These results strongly support the hypothesis that both phosphorus and iron species in calcareous marine sediments play a critical role in governing the sediment-water exchange of both phosphate and DOP in the coastal and estuarine ecosystems.

  12. Tracking riverborne sediment and contaminants in Commencement Bay, Washington, using geochemical signatures

    Science.gov (United States)

    Takesue, Renee K.; Conn, Kathleen E.; Dinicola, Richard S.

    2017-09-29

    Large rivers carry terrestrial sediment, contaminants, and other materials to the coastal zone where they can affect marine biogeochemical cycles and ecosystems. This U.S. Geological Survey study combined river and marine sediment geochemistry and organic contaminant analyses to identify riverborne sediment and associated contaminants at shoreline sites in Commencement Bay, Puget Sound, Washington, that could be used by adult forage fish and other marine organisms. Geochemical signatures distinguished the fine fraction (contaminants were measured in surface sediment did not have measurable 7Be activities in that layer, so their contaminant assemblages were attributed to sources from previous years. Concentrations of organic contaminants (the most common of which were polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and fecal sterols) were higher in the contaminants in marine rather than river sediment, indicates that riverborne sediment-bound contaminants are retained in shallow marine habitats of Commencement Bay. The retention of earlier inputs complicates efforts to identify recent inputs and sources. Understanding modern sources and fates of riverborne sediment and contaminants and their potential ecological impacts will therefore require a suite of targeted geochemical studies in such marine depositional environments.

  13. Enhanced land subsidence in Galveston Bay, Texas: Interaction between sediment accumulation rates and relative sea level rise

    Science.gov (United States)

    Al Mukaimi, Mohammad E.; Dellapenna, Timothy M.; Williams, Joshua R.

    2018-07-01

    Galveston Bay is the second largest estuary along the northern Gulf of Mexico coast, with a watershed containing one of largest concentrations of petroleum and chemical industries globally, as well as Houston, the fifth largest metropolitan area in the USA. Throughout the last century, extensive groundwater extraction to support these industries and an expanding population has resulted in significantly enhanced land subsidence (0.6-3.0 cm yr-1). The highest subsidence rates observed in the bay are within the lower 15 km of the San Jacinto River/Houston Ship Channel region (SJR/HSC), with distal areas in East and West Galveston Bays having subsidence rates on the order of 0.2 cm yr-1. In order to investigate the impacts of subsidence on sedimentation, a series of 22 vibracores were collected throughout the bay, and 210Pb and 137Cs radioisotope geochronologies and grain size distributions were determined. Sediment accumulation rates are highest (1.9 ± 0.5 cm yr-1) in the SJR/HSC, and decrease (sedimentation rates are significantly (p sedimentation rates are lower (as much as 50%) than estimated RSLR, indicating a sediment accretionary deficit. In areas (e.g., Scott Bay) within the SJR/HSC, the bay has deepened by more than 1.5 m, suggesting that sediment accumulation cannot keep pace with RSLR. Ultimately, this has resulted in a loss of coastal wetlands and a conversion of marine habitats from relatively shallow to deeper water settings.

  14. Evaluation of recent sedimentation rates in Guajara Bay (N Brazilian coast) with 210Pb and 137Cs

    International Nuclear Information System (INIS)

    Ferreira, Paulo A.L.; Neves, Patricia A.; Figueira, Rubens C.L.

    2013-01-01

    In the last 50 years the Amazon region suffered the negative effects of urban growth and industrial and agricultural development. Belem, capital city of the state of Para located, is one of its greatest urban centers, and, within its influence, Guajara Bay receives wastes discharges from Belem, which introduce many organic and inorganic contaminants to this bay. As the environmental accumulation of these pollutants is deeply related to intensity and volume of sediments deposition, this study aims to evaluate recent sedimentation rates (in a time range of 60 years) in Guajara Bay. By using high resolution gamma spectrometry, a nuclear technique proper for the analysis of radionuclides 137 Cs and 210 Pb, recent sedimentation rates were assessed in three sediment cores collected in 2011. The mean sedimentation rates found were 0.85 ± 0.12 cm yr -1 for Anadim core, 1.02 ± 0.17 cm yr -1 for Outeiro core and 0.53 ± 0.04 cm yr -1 for Tucunduba core, which are within the range of expected values for systems such as bays, estuaries and lagoons with anthropic presence (the case of Guajara Bay). (author)

  15. Modern sedimentation processes in a wave-dominated coastal embayment: Espírito Santo Bay, southeast Brazil

    Science.gov (United States)

    Bastos, Alex Cardoso; Costa Moscon, Daphnne Moraes; Carmo, Dannilo; Neto, José Antonio Baptista; da Silva Quaresma, Valéria

    2015-02-01

    Sediment dynamics in wave-dominated coastal embayments are generally controlled by seasonal meteorological conditions, storms having a particularly strong influence. In the present study, such hydrodynamic processes and associated deposits have been investigated in a coastal embayment located along the southeast coast of Brazil, i.e. Espírito Santo Bay, in the winter (June/July) of 2008. The bay has undergone a series of human interventions that have altered the local hydrodynamic processes and, consequently, the sediment transport patterns. Facies distribution and sediment dynamics were examined by acoustic seabed mapping, sediment and core sampling, hydrodynamic measurements and sand transport modelling. The results show that sediment distribution can be described in terms of nearshore and offshore zones. The offshore bay sector is predominantly composed of "palimpsest" lithoclastic medium-coarse sands deposited in the course of the early Holocene transgression that peaked about 5,000 years ago. In the inner bay or nearshore zone (up to depths of 4-8 m), these older transgressive deposits are today overlain by a thin (up to 30-cm-thick) and partly patchy blanket of younger regressive fine sand/muddy fine sands. Both coarse- and fine-grained facies are being reworked during high-energy events (Hs>1.5 m) when fine sediment is resuspended, weak tide-induced drift currents causing the sand patches to be displaced. The coarser sediment, by contrast, is mobilized as bedload to produce wave ripples with spacings of up to 1.2 m. These processes lead to a sharp spatial delimitation between a fine sand/mud facies and a rippled coarse sand facies. The fine sand patches have a relief of about 20-30 cm and reveal a typical internal tempestite depositional sequence. Fair-weather wave-induced sediment transport (Hs<1 m), supported by weak tidal currents, seems to only affect the fine sediment facies. Sediment dynamics in Espírito Santo Bay is thus essentially controlled by

  16. Neutron activation analysis to the profile surface sediments from several sites on the Havana Bay

    International Nuclear Information System (INIS)

    Diaz Riso, O.; Gelen, A.; Lopez, N.; Gonzalez, H.; Manso, M.V.; Graciano, A.M.; Nogueira, C.A.; Beltran, J.; Soto, J.

    2003-01-01

    Instrumental neutron activation analysis (INAA) technique was employed to analyze the surface sediments from several sites on the Havana Bay, Cuba. Measurements of heavy and trace elements in the sediments are reported. The results show that the concentration of the elements is site dependent. The data suggest that an anthropogenic input into the bay from domestic sewage and industries occurred

  17. Source-to-Sink constraints on tectonic and sedimentary evolution of the Central Range, Cenderawasih Bay (Indonesia) and Gulf of Papua (Papua New Guinea)

    Science.gov (United States)

    Babault, J.; Viaplana-Muzas, M.; Legrand, X.; Van Den Driessche, J.; González-Quijano, M.; Mudd, S. M.; Kergaravat, C.; Ringenbach, J. C.; Callot, J. P.; Vetel, W.; Dhont, D.

    2017-12-01

    The island of Papua New Guinea is the result of continent-arc collision that began building the island's Central Range during the late Miocene. The tectono-sedimentary evolution of the Cenderawasih Bay, in the northwestern part of the island of Papua New Guinea (Indonesia), which links the Kepala Burung block to the Central Range is still poorly understood. Previous studies have shown that this bay contains a thick (> 8 km) sequence of undated sediments. Hypothesis claim that the embayment resulted from a 3 Ma aperture created by anticlockwise rotation of the Kepala Burung block with respect to the northern rim of the Australian plate, or from the southwest drift of a slice of volcanics/oceanic crust between 8 and 6 Ma. Using a source-to-sink approach, based on i) a geomorphologic analysis of the drainage network dynamics, ii) a reassessment of available thermochronological data, and iii) seismic lines interpretation, we suggest that sediments started to accumulate in the Cenderawasih Bay and onshore in the Waipoga Basin in the late Miocene since the beginning of the Central Range building at 12 Ma, resulting in sediment accumulation of up to 12200 m. At first order, we predict that infilling is mainly composed of siliciclastics sourced in the graphite-bearing Ruffaer Metamorphic Belt and its equivalent in the Weyland Overthrust. From the unroofing paths in the Central Range we deduce two rates of solid phase accumulation (SPAR) since 12 Ma, the first one at a mean SPAR ranging between 0.12-0.25 mm/a with a maximum SPAR of 0.23-0.58 mm/a, and the second during the last 3 Ma, at a mean SPAR ranging between 0.93-1.62 mm/a and with a maximum SPAR between 2.13-3.17 mm/a, i.e., 6700-10000 m of Plio-Pleistocene sediment accumulation. Local transtensional tectonics may explain these unusually high rates of sedimentation in an overall sinistral oblique convergence setting. We further extended this approach to the Gulf of Papua (Papua New Guinea), a foreland basin developed

  18. Evaluating the potential effects of hurricanes on long-term sediment accumulation in two micro-tidal sub-estuaries: Barnegat Bay and Little Egg Harbor, New Jersey, U.S.A.

    Science.gov (United States)

    Marot, Marci E.; Smith, Christopher G.; Ellis, Alisha M.; Wheaton, Cathryn J.

    2016-06-23

    Barnegat Bay, located along the eastern shore of New Jersey, was significantly impacted by Hurricane Sandy in October 2012. Scientists from the U.S. Geological Survey (USGS) developed a multidisciplinary study of sediment transport and hydrodynamics to understand the mechanisms that govern estuarine and wetland responses to storm forcing. This report details the physical and chemical characteristics of surficial and downcore sediments from two areas within the bay. Eleven sites were sampled in both the central portion of the bay near Barnegat Inlet and in the southern portion of the bay in Little Egg Harbor. Laboratory analyses include Be-7, Pb-210, bulk density, porosity, x-radiographs, and grain-size distribution. These data will serve as a critical baseline dataset for understanding the current sedimentological regime and can be applied to future storms for understanding estuarine and wetland evolution.

  19. Study on origin and sedimentary environment of marine sediments from Kii Channel, Hiroshima Bay and Tosa Bay

    International Nuclear Information System (INIS)

    Suzuki, Misaki

    2008-01-01

    The trace amounts of elements in the sediments of sea bottom in Kii Channel, Hiroshima Bay and Tosa Bay were determined quantitatively by the neutron activation analysis. The following facts were illustrated particularly from the quantitative analysis of scandium, rare earths, thorium and uranium: 1) It was known from Ce/La ratio that the geological feature in the west part of Japan is reflected in Kii Channel, Hiroshima Bay and Tosa Bay; 2) The rare-earth element pattern and La/Lu ratio suggest the fact that Kii Channel, Hiroshima Bay and Tosa Bay are essentially composed of the materials of which origin is land; 3) From the fact that Ce/La ratio in these sites are slightly under 1.0, these sites are considered to be affected mainly by the materials of which origin is land; 4) The sedimentary environment in the marine bottom of the Japanese coasts has been found to be mostly under a reductive state. (M.H.)

  20. Distributions and contamination assessment of heavy metals in the surface sediments of western Laizhou Bay: Implications for the sources and influencing factors.

    Science.gov (United States)

    Zhang, Pan; Hu, Rijun; Zhu, Longhai; Wang, Peng; Yin, Dongxiao; Zhang, Lianjie

    2017-06-15

    Heavy metals (Cu, Pb, Cr, Cd and As) contents in surface sediments from western Laizhou Bay were analysed to evaluate the spatial distribution pattern and their contamination level. As was mainly concentrated in the coastal area near the estuaries and the other metals were mainly concentrated in the central part of the study area. The heavy metals were present at unpolluted levels overall evaluated by the sediment quality guidelines and geoaccumulation index. Principal component analysis suggest that Cu, Pb and Cd were mainly sourced from natural processes and As was mainly derived from anthropogenic inputs. Meanwhile, Cr originated from both natural processes and anthropogenic contributions. Tidal currents, sediments and human activities were important factors affecting the distribution of heavy metals. The heavy metal environment was divided into four subareas to provide a reference for understanding the distribution and pollution of heavy metals in the estuary-bay system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Sediment transport in the San Francisco Bay Coastal System: An overview

    Science.gov (United States)

    Barnard, Patrick L.; Schoellhamer, David H.; Jaffe, Bruce E.; Lester J. McKee,

    2013-01-01

    The papers in this special issue feature state-of-the-art approaches to understanding the physical processes related to sediment transport and geomorphology of complex coastal-estuarine systems. Here we focus on the San Francisco Bay Coastal System, extending from the lower San Joaquin-Sacramento Delta, through the Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic species introductions, land reclamation, and wetland restoration. The Golden Gate strait is the sole inlet connecting the Bay to the Pacific Ocean, and serves as the conduit for a tidal flow of ~ 8 x 109 m3/day, in addition to the transport of mud, sand, biogenic material, nutrients, and pollutants. Despite this physical, biological and chemical connection, resource management and prior research have often treated the Delta, Bay and adjacent ocean as separate entities, compartmentalized by artificial geographic or political boundaries. The body of work herein presents a comprehensive analysis of system-wide behavior, extending a rich heritage of sediment transport research that dates back to the groundbreaking hydraulic mining-impact research of G.K. Gilbert in the early 20th century.

  2. Sedimentation of cobalt-60 and caesium-137 released in Tvaeren, a Baltic bay

    International Nuclear Information System (INIS)

    Ramberg, L.

    1984-01-01

    The amounts of cobalt-60 and caesium-137 bound in the sediment in a bay off the Studsvik research station were determined. Of the cumulative released activity during 22 years, 19% of 60 Co and 1.8% of 137 Cs were found in the sediments within an area of 23 km 2 . The rate of input through sedimentation and the loss rate through physical decay were of the same order in 1981 and were close to steady state for 60 Co while for 137 Cs they had only reached 30% of that level. The sedimentation coefficients calculated for the bay were 6.5 year -1 for 60 Co and 0.49 year -1 for 137 Cs, higher values than many published previously. Cobalt-60 seemed to precipitate close to the outlet and to migrate near the bottom as bed-load. (author)

  3. Distribution, Source, and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Surface Sediment of Liaodong Bay, Northeast China

    Science.gov (United States)

    Xu, Shuang; Tao, Ping; Li, Yuxia; Guo, Qi; Zhang, Yan; Wang, Man; Jia, Hongliang; Shao, Mihua

    2018-01-01

    Sixteen polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediments from Liaodong Bay, northeast China. The concentration levels of total PAHs (Σ16PAHs) in sediment were 11.0˜249.6 ng·g-1 dry weight (dw), with a mean value of 89.9 ng·g-1 dry weight (dw). From the point of the spatial distribution, high PAHs levels were found in the western areas of Liaodong Bay. In the paper, sources of PAHs were investigated by diagnostic ratios, which indicated that pyrogenic sources were the main sources of PAHs in the sediment of Liaodong Bay. Therefore, selected PAH levels in sediments were compared with Sediments Quality Guidelines (ERM-ERL indexes) for evaluation probable toxic effects on marine organism.

  4. Presence of selected chemicals of emerging concern in water and bottom sediment from the St. Louis River, St. Louis Bay, and Superior Bay, Minnesota and Wisconsin, 2010

    Science.gov (United States)

    Christensen, Victoria G.; Lee, Kathy E.; Kieta, Kristen A.; Elliott, Sarah M.

    2012-01-01

    The St. Louis Bay of Lake Superior receives substantial urban runoff, wastewater treatment plant effluent, and industrial effluent. In 1987, the International Joint Commission designated the St. Louis Bay portion of the lower St. Louis River as one of the Great Lakes Areas of Concern. Concerns exist about the potential effects of chemicals of emerging concern on aquatic biota because many of these chemicals, including endocrine active chemicals, have been shown to affect the endocrine systems of fish. To determine the occurrence of chemicals of emerging concern in the St. Louis River, the St. Louis Bay, and Superior Bay, the U.S. Geological Survey in cooperation with the Minnesota Pollution Control Agency and the Wisconsin Department of Natural Resources collected water and bottom-sediment samples from 40 sites from August through October 2010. The objectives of this study were to (1) identify the extent to which chemicals of emerging concern, including pharmaceuticals, hormones, and other organic chemicals, occur in the St. Louis River, St. Louis Bay, and Superior Bay, and (2) identify the extent to which the chemicals may have accumulated in bottom sediment of the study area. Samples were analyzed for selected wastewater indicators, hormones, sterols, bisphenol A, and human-health pharmaceuticals. During this study, 33 of 89 chemicals of emerging concern were detected among all water samples collected and 56 of 104 chemicals of emerging concern were detected in bottom-sediment samples. The chemical N,N-diethyl-meta-toluamide (DEET) was the most commonly detected chemical in water samples and 2,6-dimethylnaphthalene was the most commonly detected chemical in bottom-sediment samples. In general, chemicals of emerging concern were detected at a higher frequency in bottom-sediment samples than in water samples. Estrone (a steroid hormone) and hexahydrohexamethyl cyclopentabensopyran (a synthetic fragrance) were the most commonly detected endocrine active chemicals in

  5. Ecosystem history of South Florida; Biscayne Bay sediment core descriptions

    Science.gov (United States)

    Ishman, S.E.

    1997-01-01

    The 'Ecosystem History of Biscayne Bay and the southeast Coast' project of the U.S. Geological Survey is part of a multi-disciplinary effort that includes Florida Bay and the Everglades to provide paleoecologic reconstructions for the south Florida region. Reconstructions of past salinity, nutrients, substrate, and water quality are needed to determine ecosystem variability due to both natural and human-induced causes. Our understanding of the relations between the south Florida ecosystem and introduced forces will allow managers to make informed decisions regarding the south Florida ecosystem restoration and monitoring. The record of past ecosystem conditions can be found in shallow sediment cores. This U.S. Geological Survey Open-File Report describes six shallow sediment cores collected from Biscayne Bay. The cores described herein are being processed for a variety of analytical procedures, and this provides the descriptive framework for future analyses of the included cores. This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

  6. Butiltins Compound in Seawater and Sediment of Banten Bay

    Directory of Open Access Journals (Sweden)

    Hamidah Razak

    2004-08-01

    Full Text Available bservation on butiltin (BTs compound content in seawater and sediments from Banten Bay were conducted in August 2003 and October 2003. Butiltin content including TBT, DBT and MBT on August 2003 respectively range between <2ng Sn/l, <2 to 9 ng Sn/l and < 5 to 17 ng Sn/l and on October 2003 was found respectively nd to <2 ng Sn/l, <0.5 to 12 ng Sn/g, 0.5 to 2.7 ng Sn/g and <0.5 to 2.2 ng Sn/g, and on October 2003 was found varied from <0.5 to 4.2ng Sn/g, <0.5 to 1.1ng Sn/g and <0.5 to 1 ng Sn/g. Content of TBT was found on August 2003 higher than October 03 and also the content of TBT compound in sediments was high compared to waters. It indicated that there was accumulation of TBT in sediment. The minimal risk of TBT in seaport and for marine life according to Minister of environment in Keputusan Menteri Negara Kependudukan dan Lingkungan Hidup No.51 tahun 2004 is 10 ng/l. The results showed that Banten Bay is still appropiate for seaport and marine life.

  7. Suspended-sediment dynamics in the tidal reach of a San Francisco Bay tributary

    Science.gov (United States)

    Shellenbarger, Gregory; Downing-Kunz, Maureen; Schoellhamer, David H.

    2015-01-01

    To better understand suspended-sediment transport in a tidal slough adjacent to a large wetland restoration project, we deployed continuously measuring temperature, salinity, depth, turbidity, and velocity sensors in 2010 at a near-bottom location in Alviso Slough (Alviso, California, USA). Alviso Slough is the downstream reach of the Guadalupe River and flows into the far southern end of San Francisco Bay. River flow is influenced by the Mediterranean climate, with high flows (∼90 m3 s−1) correlated to episodic winter storms and low base flow (∼0.85 m3 s−1) during the summer. Storms and associated runoff have a large influence on sediment flux for brief periods, but the annual peak sediment concentrations in the slough, which occur in April and May, are similar to the rest of this part of the bay and are not directly related to peak discharge events. Strong spring tides promote a large upstream sediment flux as a front associated with the passage of a salt wedge during flood tide. Neap tides do not have flood-directed fronts, but a front seen sometimes during ebb tide appears to be associated with the breakdown of stratification in the slough. During neap tides, stratification likely suppresses sediment transport during weaker flood and ebb tides. The slough is flood dominant during spring tides, and ebb dominant during neap tides. Extreme events in landward (salt wedge) and bayward (rainfall events) suspended-sediment flux account for 5.0 % of the total sediment flux in the slough and only 0.55 % of the samples. The remaining 95 % of the total sediment flux is due to tidal transport, with an imbalance in the daily tidal transport producing net landward flux. Overall, net sediment transport during this study was landward indicating that sediment in the sloughs may not be flushed to the bay and are available for sedimentation in the adjacent marshes and ponds.

  8. HEAVY METAL CONTENTS IN MARINE SEDIMENTS AND SEAWATER AT TOTOK BAY AREA, NORTH SULAWESI

    Directory of Open Access Journals (Sweden)

    Delyuzar Ilahude

    2017-07-01

    Full Text Available The study area is located in north-eastern part of Tomini Bay, approximately 80 km south of Manado city, North Sulawesi. This area is closed to submarine tailing disposal system in Buyat Bay. Five marine sediment samples and four water samples from seawater and dig wells have been used for heavy metals (Hg, As, CN analyses by using Atomic Absorption Spectrometry (AAS. This study is a part of research conducted by Marine Geological Institute of Indonesia on morphological changes of seabed in the Totok Bay. The result shows that concentration of mercury (Hg in water samples taken from Ratatotok estuary is higher than standards stipulated Government Regulation (Peraturan Pemerintah/PP No. 82/2001. Meanwhile, concentration of arsenic (As is almost reaching its standard threshold, and conversely cyanide (CN concentration is low. This value of mercury (Hg concentration taken from Ratatotok estuary is much higher than water samples from of Buyat Bay estuary. Significant concentration of mercury (Hg analysed from those particular sampling sites indicated high mercury contamination. Therefore, further examination on ground water of dig wells is necessary, especially for mercury analysis (Hg. Furthermore, comparing the formerly obtained data of mercury concentration in the sediment, this particular study concludes that the sediments in the Totok Bay had contaminated by mercury from gold-processing of illegal mining.

  9. QUANTIFYING SEDIMENT CONTRIBUTIONS TO THE GUÁNICA BAY PUERTO RICO

    Science.gov (United States)

    The island of Puerto Rico faces considerable challenges regarding sustainable land use and effects of land use on adjacent freshwater and marine ecosystem services. In watersheds feeding Guánica Bay (southwestern Puerto Rico), increased soil erosion and sediment loading to strea...

  10. Combining contamination indexes, sediment quality guidelines and multivariate data analysis for metal pollution assessment in marine sediments of Cienfuegos Bay, Cuba.

    Science.gov (United States)

    Peña-Icart, Mirella; Pereira-Filho, Edenir Rodrigues; Lopes Fialho, Lucimar; Nóbrega, Joaquim A; Alonso-Hernández, Carlos; Bolaños-Alvarez, Yoelvis; Pomares-Alfonso, Mario S

    2017-02-01

    The purpose of the present work was to combine several tools for assessing metal pollution in marine sediments from Cienfuegos Bay. Fourteen surface sediments collected in 2013 were evaluated. Concentrations of As, Cu, Ni, Zn and V decreased respect to those previous reported. The metal contamination was spatially distributed in the north and south parts of the bay. According to the contamination factor (CF) enrichment factor (EF) and index of geoaccumulation (I geo ), Cd and Cu were classified in that order as the most contaminated elements in most sediment. Comparison of the total metal concentrations with the threshold (TELs) and probable (PELs) effect levels in sediment quality guidelines suggested a more worrisome situation for Cu, of which concentrations were occasional associated with adverse biological effects in thirteen sediments, followed by Ni in nine sediments; while adverse effects were rarely associated with Cd. Probably, Cu could be considered as the most dangerous in the whole bay because it was classified in the high contamination levels by all indexes and, simultaneously, associated to occasional adverse effects in most samples. Despite the bioavailability was partially evaluated with the HCl method, the low extraction of Ni (<3% in all samples) and Cu (<55%, except sample 3) and the relative high extraction of Cd (50% or more, except sample 14) could be considered as an attenuating (Ni and Cu) or increasing (Cd) factor in the risk assessment of those element. Copyright © 2016. Published by Elsevier Ltd.

  11. Chemical and isotopic characterisation and sedimentation rates in Princess Charlotte Bay, Queensland

    International Nuclear Information System (INIS)

    Torgersen, T.; Chivas, A.R.; Chapman, A.

    1983-01-01

    Sedimentation rates in Princess Charlotte Bay are in the range 2.3-6.1 mm/yr, with mixed layers up to 10 cm thick, as determined by the 210 Pb method. 137 Cs determinations of sedimentation rate are not in disagreement, but are likely to yield ambiguous results in the Great Barrier Reef Province, because of diffusive redistribution, owing to the low distribution coefficient, K/sub D/ = 420-800, measured in lagoonal sediments

  12. Methodical Features of the Field Researches of the Anapa Bay-Bar Sediment Composition

    Science.gov (United States)

    Krylenko, Marina; Krylenko, Viacheslav; Gusakova, Anastasiya; Kosyan, Alisa

    2014-05-01

    Resort Anapa (Black Sea coast, Russia) holds leading positions in the Russian market of sanatorium-resort and children's recreation. The 50-200 m sandy beaches of Anapa bay-bar are the main value of the resort. Anapa bay-bar is an extensive accumulative sandy body having the length about 47 km. Obvious attributes of the beaches degradation demanding immediate measures on their protection and restoration are observed in last years. The main reason of degradation is beach material deficiency. To organize researches of the sediments of this extensive natural object is a difficult challenge. It is necessary to reduce number of tests to minimum. It is important to record differences of separate bay-bar sites and to receive comparable data for different seasons and years. Our researches showed that the grain-size sediment composition significantly depends of position on local relief. Consequently, researching of the alongshore change of the sediment size is effectual to realize at this morphological elements. Shelly detritus makes to 30% of total amount of beach sediments. It is necessary to consider that quantitative shell distribution along the coast significantly depends on a configuration of the coastline and an underwater relief. Quantity of the shells for cross-shore profile is maximal near coastline. For identification of the sediment sources and researching of their fluxes to use minerals markers (heavy minerals) is optimum. The maximum of heavy minerals concentration is characteristic for fraction 0.1-0.05mm at depth more 5 m. The maintenance of this fraction within other morphological zones isn't enough for the analysis or is excessively changeable. Use of the revealed features allowed to conduct the representative field researches of grain-size and mineral sediment composition for all morphological zones of underwater and coast part of the Anapa bay-bar. This methodic recommendations are workable for researches on others coast accumulative body. The work is

  13. Evaluation of recent sedimentation rates in Guajara Bay (N Brazilian coast) with {sup 210}Pb and {sup 137}Cs

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Paulo A.L.; Neves, Patricia A.; Figueira, Rubens C.L., E-mail: paulo.alves.ferreira@usp.br, E-mail: ticinev@yahoo.com.br, E-mail: rfigueira@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto Oceanografico

    2013-07-01

    In the last 50 years the Amazon region suffered the negative effects of urban growth and industrial and agricultural development. Belem, capital city of the state of Para located, is one of its greatest urban centers, and, within its influence, Guajara Bay receives wastes discharges from Belem, which introduce many organic and inorganic contaminants to this bay. As the environmental accumulation of these pollutants is deeply related to intensity and volume of sediments deposition, this study aims to evaluate recent sedimentation rates (in a time range of 60 years) in Guajara Bay. By using high resolution gamma spectrometry, a nuclear technique proper for the analysis of radionuclides {sup 137}Cs and {sup 210}Pb, recent sedimentation rates were assessed in three sediment cores collected in 2011. The mean sedimentation rates found were 0.85 ± 0.12 cm yr{sup -1}for Anadim core, 1.02 ± 0.17 cm yr{sup -1}for Outeiro core and 0.53 ± 0.04 cm yr{sup -1}for Tucunduba core, which are within the range of expected values for systems such as bays, estuaries and lagoons with anthropic presence (the case of Guajara Bay). (author)

  14. Seasonal variability in the surface sediments of Mobile Bay, Alabama, recorded by geochemistry and foraminifera, 2009–2010

    Science.gov (United States)

    Umberger, D.K.; Osterman, L.E.; Smith, C.G.; Frazier, J.; Richwine, K.A.

    2012-01-01

    A study was undertaken in order to document and quantify recent environmental change in Mobile Bay, Alabama. The study was part of the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility project, a regional project funded by the Coastal and Marine Geology Program to understand how natural forcings and anthropogenic modifications influence coastal ecosystems and their susceptibility to coastal hazards. Mobile Bay is a large drowned-river estuary that has been modified significantly by humans to accommodate the Port of Mobile. Examples include repeated dredging of a large shipping channel down the central axis of the bay and construction of a causeway across the head of the bay and at the foot of the bayhead delta. In addition to modifications, the bay is also known to have episodic periods of low oxygen (hypoxia) that result in significant mortality to fish and benthic organisms (May, 1973). For this study a series of surface sediment samples were collected. Surface benthic foraminiferal and bulk geochemical data provide the modern baseline conditions of the bay and can be used as a reference to changing environmental parameters in the past (Osterman and Smith, in press) and into the future. This report archives data collected as part of the Mobile Bay Study that may be used in future environmental change studies.

  15. Evolution of sediment plumes in the Chesapeake bay and implications of climate variability.

    Science.gov (United States)

    Zheng, Guangming; DiGiacomo, Paul M; Kaushal, Sujay S; Yuen-Murphy, Marilyn A; Duan, Shuiwang

    2015-06-02

    Fluvial sediment transport impacts fisheries, marine ecosystems, and human health. In the upper Chesapeake Bay, river-induced sediment plumes are generally known as either a monotonic spatial shape or a turbidity maximum. Little is known about plume evolution in response to variation in streamflow and extreme discharge of sediment. Here we propose a typology of sediment plumes in the upper Chesapeake Bay using a 17 year time series of satellite-derived suspended sediment concentration. On the basis of estimated fluvial and wind contributions, we define an intermittent/wind-dominated type and a continuous type, the latter of which is further divided into four subtypes based on spatial features of plumes, which we refer to as Injection, Transport, Temporary Turbidity-Maximum, and Persistent Turbidity-Maximum. The four continuous types exhibit a consistent sequence of evolution within 1 week to 1 month following flood events. We also identify a "shift" in typology with increased frequency of Turbidity-Maximum types before and after Hurricane Ivan (2004), which implies that extreme events have longer-lasting effects upon estuarine suspended sediment than previously considered. These results can serve as a diagnostic tool to better predict distribution and impacts of estuarine suspended sediment in response to changes in climate and land use.

  16. Multielemental analysis to the profile sediments from several sites on the Havana Bay, by the Neutron activation analysis

    International Nuclear Information System (INIS)

    Diaz Riso, O.; Gelen, A.; Lopez, N.; Manso, M.V.; Graciano, A.M.; Nogueira, C.A.; Beltran, J.

    2003-01-01

    Instrumental neutron activation analysis (INAA) technique was employed to analyze the profile sediments from several sites on the Havana Bay, Cuba. Measurements of 24 heavy and trace elements in the sediments are reported. The results show the increment in the sediment pollution occurred in the 70-80 years of the last century. The data confirm that an anthropogenic input into the bay from domestic sewage and industries occurred

  17. Mapping the extent and relative toxicity of sediments, Winter Quarters Bay, Antarctica

    International Nuclear Information System (INIS)

    Crockett, A.; White, G.; Huynh, H.

    1995-01-01

    McMurdo Station was established in the mid 1950s and is the largest research station in Antarctica. In earlier days, wastes were dumped on the steep shores of Winter Quarters Bay, dosed with up to 19,000 L of diesel or jet fuel and ignited. Along with periodic fuel spills, and the discharge of raw sewage the Bay became littered with trash and contaminated with elevated levels of metals, PCBs and petroleum hydrocarbons. The original benthic community was essentially totally replaced with more opportunistic species. In 1993, a study was initiated to map the distribution of PCB and hydrocarbon contamination as well as determine sediment pore water toxicity. Sediments were collected from over forty locations with an Ekman dredge after drilling through about 210 cm of ice. Maps of sediment particle size distribution, percent organic carbon, total PCBs, total petroleum hydrocarbons, etc. were developed. Potential toxicity was mapped by normalizing the data to 1 percent organic carbon and comparing the data with various sediment quality criteria. While onsite sediment pore water toxicity tests showed essentially no impacts, the new Microtox trademark chronic bioassay on both pore water and solvent extra showed considerable toxic effects. This paper compares the relative levels of contamination, with sediment quality criteria and toxicity as determined by a chronic microbial bioassays

  18. Determination of heavy metals and other elements in sediments from Sepetiba Bay (RJ, Brazil) by neutron activation analysis

    International Nuclear Information System (INIS)

    Pellegatti, Fabio

    2000-01-01

    Sepetiba Bay, located about 60 km south of the city of Rio de Janeiro, Brazil, is one of the most important fishery areas in the State of Rio de Janeiro. A large harbor brought up a lot of industrial investment in that area. Since the 1970's, the Sepetiba region has undergone fast industrial expansion, leading to high levels of pollution by metals. For the last two decades, an industrial park composed of about 400 industrial plants, basically metallurgical, was established in the Sepetiba Bay basin, releasing its industrial waste either straight into the bay or through local rivers. Metal contamination in the bay for some metals, such as Zn, has already exceeded acceptable levels. Many authors have studied the distribution and behavior of heavy metals and another elements in the bay, but only few elements have been focused (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn). This is probably due to the fact that the analytical technique most employed has been atomic absorption spectrometry, which is not a multi-elemental technique. In this work, Instrumental Neutron Activation Analysis (INAA) was applied to the determination of the elements As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Nd, Rb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn in 28 bottom sediment samples and four sediment cores from Sepetiba Bay. The elements Co, Cr, Cs, Fe, Sc, Ta and Zn presented similar behavior in the bottom sediments, showing higher concentration along the Northern coast of the bay, where most of the fluvial water flows out to the bay. The contamination of Sepetiba Bay was also assessed by the analysis of four sediment cores. Two of them were sampled in the Eastern part of the bay, where the industrial park is located, whereas the other two were sampled in the Western part of the bay, a more preserved region. For each region, two cores were sampled within the mangrove trees and the others at the edge of the tidal flat. The results showed that, the sediments displayed higher metal concentration within the

  19. Metagenomic evidence for reciprocal particle exchange between the mainstem estuary and lateral bay sediments of the lower Columbia River

    Directory of Open Access Journals (Sweden)

    Mariya W Smith

    2015-10-01

    Full Text Available Lateral bays of the lower Columbia River estuary are areas of enhanced water retention that influence net ecosystem metabolism through activities of their diverse microbial communities. Metagenomic characterization of sediment microbiota from three disparate sites in two brackish lateral bays (Baker and Youngs produced approximately 100 Gbp of DNA sequence data analyzed subsequently for predicted SSU rRNA and peptide-coding genes. The metagenomes were dominated by Bacteria. A large component of Eukaryota was present in Youngs Bay samples, i.e. the inner bay sediment was enriched with the invasive New Zealand mudsnail, Potamopyrgus antipodarum, known for high ammonia production. The metagenome was also highly enriched with an archaeal ammonia oxidizer closely related to Nitrosoarchaeum limnia. Combined analysis of sequences and continuous, high-resolution time series of biogeochemical data from fixed and mobile platforms revealed the importance of large-scale reciprocal particle exchanges between the mainstem estuarine water column and lateral bay sediments. Deposition of marine diatom particles in sediments near Youngs Bay mouth was associated with a dramatic enrichment of Bacteroidetes (58% of total Bacteria and corresponding genes involved in phytoplankton polysaccharide degradation. The Baker Bay sediment metagenome contained abundant Archaea, including diverse methanogens, as well as functional genes for methylotrophy and taxonomic markers for syntrophic bacteria, suggesting that active methane cycling occurs at this location. Our previous work showed enrichments of similar anaerobic taxa in particulate matter of the mainstem estuarine water column. In total, our results identify the lateral bays as both sources and sinks of biogenic particles significantly impacting microbial community composition and biogeochemical activities in the estuary.

  20. Depth profile distribution of Cr, Cu, Co, Ni and Pb in the sediment cores of Mumbai Harbour Bay

    International Nuclear Information System (INIS)

    Madhuparna, D.; Hemalatha, P.; Raj, Sanu S.; Jha, S.K.; Tripathi, R.M.

    2014-01-01

    Estuarine and coastal sediments act as ultimate sink for trace metals that are discharged into the aquatic environment. Sources of environmental contaminants to the coastal system are numerous and may enter the estuarine environment via a number of pathways Mumbai Harbour Bay on the western coast of India, receives low level nuclear wastes and industrial and domestic sewage waste from the surrounding dwellings. Also, the bay is extensively exploited for various other local activities. The present study was carried out in the bay sediment cores to investigate the depth profile distribution of trace element concentration. Biologically significant toxic elements such as Cr, Cu, Co, Ni and Pb were estimated in the sediment cores to find out pattern of distribution in the sediment bed to follow the accumulation of elements with respect to depth

  1. Chesapeake Bay impact structure: A blast from the past

    Science.gov (United States)

    Powars, David S.; Edwards, Lucy E.; Gohn, Gregory S.; Horton, J. Wright

    2015-10-28

    About 35 million years ago, a 2-mile-wide meteorite smashed into Earth in what is now the lower Chesapeake Bay in Virginia. The oceanic impact vaporized, melted, fractured, and displaced rocks and sediments and sent billions of tons of water, sediments, and rocks into the air. Glassy particles of solidified melt rock rained down as far away as Texas and the Caribbean. Large tsunamis affected most of the North Atlantic basin. The resulting impact structure is more than 53 miles wide and has a 23-mile-wide, filled central crater surrounded by collapsed sediments. Now buried by hundreds of feet of younger sediments, the Chesapeake Bay impact structure is among the 20 largest known impact structures on Earth.

  2. Spatial distribution of heavy metals in surficial sediments from Guanabara Bay: Rio de Janeiro, Brazil

    Science.gov (United States)

    Neto, José Antônio Baptista; Gingele, Franz Xaver; Leipe, Thomas; Brehme, Isa

    2006-04-01

    Ninety-two surface sediment samples were collected in Guanabara Bay, one of the most prominent urban bays in SE Brazil, to investigate the spatial distribution of anthropogenic pollutants. The concentrations of heavy metals, organic carbon and particle size were examined in all samples. Large spatial variations of heavy metals and particle size were observed. The highest concentrations of heavy metals were found in the muddy sediments from the north western region of the bay near the main outlets of the most polluted rivers, municipal waste drainage systems and one of the major oil refineries. Another anomalous concentration of metals was found adjacent to Rio de Janeiro Harbour. The heavy metal concentrations decrease to the northeast, due to intact rivers and the mangrove systems in this area, and to the south where the sand fraction and open-marine processes dominate. The geochemical normalization of metal data to Li or Al has also demonstrated that the anthropogenic input of heavy metals have altered the natural sediment heavy metal distribution.

  3. Dynamics of sediment carbon stocks across intertidal wetland habitats of Moreton Bay, Australia.

    Science.gov (United States)

    Hayes, Matthew A; Jesse, Amber; Hawke, Bruce; Baldock, Jeff; Tabet, Basam; Lockington, David; Lovelock, Catherine E

    2017-10-01

    Coastal wetlands are known for high carbon storage within their sediments, but our understanding of the variation in carbon storage among intertidal habitats, particularly over geomorphological settings and along elevation gradients, is limited. Here, we collected 352 cores from 18 sites across Moreton Bay, Australia. We assessed variation in sediment organic carbon (OC) stocks among different geomorphological settings (wetlands within riverine settings along with those with reduced riverine influence located on tide-dominated sand islands), across elevation gradients, with distance from shore and among habitat and vegetation types. We used mid-infrared (MIR) spectroscopy combined with analytical data and partial least squares regression to quantify the carbon content of ~2500 sediment samples and provide fine-scale spatial coverage of sediment OC stocks to 150 cm depth. We found sites in river deltas had larger OC stocks (175-504 Mg/ha) than those in nonriverine settings (44-271 Mg/ha). Variation in OC stocks among nonriverine sites was high in comparison with riverine and mixed geomorphic settings, with sites closer to riverine outflow from the east and south of Moreton Bay having higher stocks than those located on the sand islands in the northwest of the bay. Sediment OC stocks increased with elevation within nonriverine settings, but not in riverine geomorphic settings. Sediment OC stocks did not differ between mangrove and saltmarsh habitats. OC stocks did, however, differ between dominant species across the research area and within geomorphic settings. At the landscape scale, the coastal wetlands of the South East Queensland catchments (17,792 ha) are comprised of approximately 4,100,000-5,200,000 Mg of sediment OC. Comparatively high variation in OC storage between riverine and nonriverine geomorphic settings indicates that the availability of mineral sediments and terrestrial derived OC may exert a strong influence over OC storage potential across

  4. Heavy metals pollution and pb isotopic signatures in surface sediments collected from Bohai Bay, North China.

    Science.gov (United States)

    Gao, Bo; Lu, Jin; Hao, Hong; Yin, Shuhua; Yu, Xiao; Wang, Qiwen; Sun, Ke

    2014-01-01

    To investigate the characteristics and potential sources of heavy metals pollution, surface sediments collected from Bohai Bay, North China, were analyzed for the selected metals (Cd, Cr, Cu, Ni, Pb, and Zn). The Geoaccumulation Index was used to assess the level of heavy metal pollution. Pb isotopic compositions in sediments were also measured to effectively identify the potential Pb sources. The results showed that the average concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 0.15, 79.73, 28.70, 36.56, 25.63, and 72.83 mg/kg, respectively. The mean concentrations of the studied metals were slightly higher than the background values. However, the heavy metals concentrations in surface sediments in Bohai Bay were below the other important bays or estuaries in China. The assessment by Geoaccumulation Index indicated that Cr, Zn, and Cd were classified as "the unpolluted" level, while Ni, Cu, and Pb were ranked as "unpolluted to moderately polluted" level. The order of pollution level of heavy metals was: Pb > Ni > Cu > Cr > Zn > Cd. The Pb isotopic ratios in surface sediments varied from 1.159 to 1.185 for (206)Pb/(207)Pb and from 2.456 to 2.482 for (208)Pb/(207)Pb. Compared with Pb isotopic radios in other sources, Pb contaminations in the surface sediments of Bohai Bay may be controlled by the mix process of coal combustion, aerosol particles deposition, and natural sources.

  5. Sediment Chemistry and Toxicity in Barnegat Bay, New Jersey: Pre- and Post- Hurricane Sandy, 2012-2013.

    Science.gov (United States)

    Romanok, Kristin M.; Szabo, Zoltan; Reilly, Timothy J.; Defne, Zafer; Ganju, Neil K.

    2016-01-01

    Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especially north of Barnegat Inlet, consistent with northward redistribution of silt. Loss of organic compounds, clay, and organic carbon is consistent with sediment winnowing and transport through the inlets and sediment transport modeling results. The number of sites exceeding sediment quality guidance levels for trace elements tripled post-Sandy. Sediment toxicity post-Sandy was mostly unaffected relative to pre-Sandy conditions, but at the site with the greatest relative increase for trace elements, survival rate of the test amphipod decreased (indicating degradation). This study would not have been possible without comprehensive baseline data enabling the evaluation of storm-derived changes in sediment quality.

  6. Distribution of polycyclic aromatic hydrocarbons in water and surface sediments from Daya Bay, China

    International Nuclear Information System (INIS)

    Zhou, J.L.; Maskaoui, K.

    2003-01-01

    Findings indicate an urgent need to establish a monitoring program for persistent organic pollutants in water and sediment. - Marine culture is thriving in China and represents a major component of the regional economy in coastal zones, yet the environmental quality of many of those areas has never been studied. This paper attempts to investigate the quality status of Daya Bay, a key aquaculture area in China. The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in water and sediment samples of the bay. The total concentrations of 16 PAHs varied from 4228 to 29325 ng l -1 in water, and from 115 to 1134 ng g -1 dry weight in sediments. In comparison to many other marine systems studied, the PAH levels in Daya Bay waters were relatively high, and at six sites they were sufficiently high (>10 μg l -1 ) to cause acute toxicity. The PAH composition pattern in sediments suggest dominance by medium to high molecular weight compounds, and the ratio of certain related PAHs indicate important pyrolytic and petrogenic sources. Further analysis showed that the distribution coefficient (K D ) increased with the particular organic carbon content of sediments, consistent with the PAH partition theory. The organic carbon normalised distribution coefficient (K oc ) also increased with the compounds' octanol/water partition coefficient (K ow ), confirming the potential applicability of the linear free energy relationships in the modelling and prediction of PAH behaviour in marine environments

  7. Ecological risk, source and preliminary assessment of metals in the surface sediments of Chabahar Bay, Oman Sea

    International Nuclear Information System (INIS)

    Agah, Homira; Saleh, Abolfazl; Bastami, Kazem Darvish; Fumani, Neda Sheijooni

    2016-01-01

    In this study, concentrations of Aluminum (Al), Iron (Fe), Chromium (Cr), Copper (Cu), Nickel (Ni), Vanadium (V), Zinc (Zn), Arsenic (As), Cobalt (Co) and lead (Pb) in the surface sediments from Chabahar Bay were studied to assess the degree of heavy metal pollution as a consequence of natural and anthropogenic sources. Metal contents in the sediments were observed in the order of: Al > Fe > Cr > V > Ni > Zn > Cu > > As > Pb > Co. According to enrichment factor (EF), Arsenic was higher than 1.5 at some sites, indicating anthropogenic inputs. Contents of Ni, As and Cr in the some sampling sites were higher than sediment quality guideline implying adverse impacts of these metals. Based on potential ecological risk (PER), the Chabahar Bay had low ecological risk. - Highlights: •Metals and major elements were determined in surface sediments from Chabahar Bay, Oman Sea. •EF values indicated non-enriched to moderate-enriched. •Ni, As and Cr were above ERL values.

  8. Differential leaching of 137Cs from sediment core depth fractions of Bombay harbour bay

    International Nuclear Information System (INIS)

    Hemalatha, P.; Desai, M.V.M.

    1998-01-01

    Bombay harbour bay receives 137 Cs from the effluents of research reactors, fuel reprocessing plant and isotope laboratories. 137 Cs is strongly taken up by suspended particulates and sediments and is trapped in the layer lattices of the clay minerals. As the siltation rate is high in the bay, 137 Cs gets distributed vertically along the depth of sediment. NaCl solution has been proved to desorb 137 Cs from clay minerals effectively. NaCl solution of ionic strength 1.6 was used to desorb 137 Cs from depth fractions of a sediment core to obtain a possible gradient of leaching with the depth. A definite rate of leaching was observed for the 137 Cs in the core sediment depth fractions. About 13% to 56% of 137 Cs was leached. As the depth increases removal rate of cesium decreases. This is expected to bring out a relation between age of 137 Cs and rate of its leaching. (author)

  9. Environmental assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Santander Bay, Northern Spain.

    Science.gov (United States)

    Viguri, J; Verde, J; Irabien, A

    2002-07-01

    Samples of intertidal surface sediments (0-2 cm) were collected in 17 stations of the Santander Bay, Cantabric Sea, Northern Spain. The concentrations of polycyclic aromatic hydrocarbons (PAHs), 16, were analysed by HPLC and MS detection. Surface sediments show a good linear correlation among the parameters of the experimental organic matter evaluation, where total carbon (TC) and loss on ignition (LOI) are approximately 2.5 and 5 times total organic carbon (TOC). A wide range of TOC from 0.08% to 4.1%, and a broad distribution of the sum of sigma16PAHs, from 0.02 to 344.6 microg/g d.w., which can be correlated by an exponential equation to the TOC, has been identified. A qualitative relationship may be established between the industrial input along the rivers and the concentration of sigma6PAHs in the sediments of the estuaries: Boo estuary (8404-4631 microg/g OC), Solia-San Salvador estuaries (305-113 microg/g OC) and Cubas estuary (31-32 microg/g OC). This work shows a dramatic change in the spatial distribution in the concentration of PAHs of intertidal surface sediments. The left edge of the Bay has the main traffic around the city and the major source of PAHs is from combustion processes and estuarine inputs, leading to medium values of PAHs in the sediments; the right edge of the Bay has much lesser anthropogenic activities leading to lower values of PAHs in sediments. The distribution of individual PAHs in sediments varies widely depending on their structure and molecular weight; the 4-6 ring aromatics predominate in polluted sediments due to their higher persistence. The isomer ratio does not allow any clear identification of the PAHs origin. Environmental evaluation according to Dutch guidelines and consensus sediment quality guidelines based on ecotoxicological data leads to the same conclusion, sediments in the Santander Bay show a very different environmental quality depending on the spatial position from heavily polluted/medium effects to non

  10. Prokaryotic community composition involved production of nitrogen in sediments of Mejillones Bay

    International Nuclear Information System (INIS)

    Moraga, Ruben; Galan, Alexander; Rosello-Mora, Ramon; Araya, Ruben; Valdes, Jorge

    2014-01-01

    Conventional denitrification and anaerobic ammonium oxidation (anammox) contributes to nitrogen loss in oxygen-deficient systems, thereby influencing many aspects of ecosystem function and global biogeochemistry. Mejillones Bay, northern Chile, presents ideal conditions to study nitrogen removal processes, because it is inserted in a coastal upwelling system, its sediments have anoxia and hypoxia conditions and under the influence of the Oxygen Minimum Zone (OMZ), unknown processes that occur there and what are the microbial communities responsible for their removal. Microbial communities associated with coastal sediments of Mejillones Bay were studied by denaturing gel electrophoresis (DGGE) and fluorescence in situ hybridization (FISH), by incubation experiments with 15 N isotope tracers were studied nitrogen loss processes operating in these sediments. DGGE analysis showed high bacterial diversity, certain redundant phylotypes and differences in community structure given by the depth; this reflects the microbial community adaptations to environmental conditions. A large fraction (up to 70%) of DAPI-stained cells hybridized with the bacterial probes. Nearly 52-90% of the cell could be further identified to know phyla. Members of the Cytophaga-Flavobacterium cluster were most abundant in the sediments (13-26%), followed by Proteobacteria. Isotopic tracer experiments for the sediments studied indicated that nitrogen loss processes that predominated were performed by denitrifying communities (43.31-111.20 μMd -1 ) was not possible to detect anammox in the area and not anammox bacteria were detected

  11. Study of recent changes in sedimentation regime inside Cienfuegos Bay, Cuba using 210Pb and 137Cs as tracers

    International Nuclear Information System (INIS)

    Alonso-Hernandez, A.; Delfanti, R.; Papucci, C.; Diaz-Asencio, M.; Munoz-Caravaca, A.

    2002-01-01

    Sedimentation dynamics in the Cienfuegos Bay was investigated based on profiles and inventories of 210 Pb ex and 137 Cs in cores collected at two sites. The age of sediment layers was determined using the CRS model. Both cores show changes in sedimentation regime in the last 40 years. Since 1960-1965 sediment accumulation rates have doubled in both cells of the bay, from 0.2 to 0.4 g.cm -2 .y -1 . This change was probably one of the factors that influenced the important environmental modifications observed in the area. (author)

  12. Distribution and temporal variation of trace metal enrichment in surface sediments of San Jorge Bay, Chile.

    Science.gov (United States)

    Valdés, Jorge; Román, Domingo; Guiñez, Marcos; Rivera, Lidia; Morales, Tatiana; Morales, Tomás; Avila, Juan; Cortés, Pedro

    2010-08-01

    Cu, Pb, and Hg concentrations were determined in surface sediment samples collected at three sites in San Jorge Bay, northern Chile. This study aims to evaluate differences in their spatial distribution and temporal variability. The highest metal concentrations were found at the site "Puerto", where minerals (Cu and Pb) have been loaded for more than 60 years. On the other hand, Hg does not pose a contamination problem in this bay. Cu and Pb concentrations showed significant variations from 1 year to another. These variations seem to be a consequence of the combination of several factors, including changes in the loading and/or storage of minerals in San Jorge Bay, the dredging of bottom sediments (especially at Puerto), and seasonal changes in physical-chemical properties of the water column that modify the exchange of metals at the sediment-water interface. Differences in the contamination factor and geoaccumulation index suggest that pre-industrial concentrations measured in marine sediments of this geographical zone, were better than geological values (average shale, continental crust average) for evaluating the degree of contamination in this coastal system. Based on these last two indexes, San Jorge Bay has a serious problem of Cu and Pb pollution at the three sampling locations. However, only Cu exceeds the national maximum values used to evaluate ecological risk and the health of marine environments. It is suggested that Chilean environmental legislation for marine sediment quality--presently under technical discussion--is not an efficient tool for protecting the marine ecosystem.

  13. Natural and man-made radionuclide concentrations in marine sediments of Gokova Bay, Aegean Turkish coast

    International Nuclear Information System (INIS)

    Tanbay, A.U.; Yener, G.; Mulsow, S.; Fowler, S.W.; Duman, M.

    1999-01-01

    The purpose of this research is to define a baseline study of selected radionuclides (natural and man made) on sediments collected along Goekova Bay. A total of six sediment cores (gravity corer) were collected, each sediment core was sliced in sections and 210 Po, 210 Pb, 226 Ra, 232 Th and 40 K and 137 Cs, 239,240 Pu, 238 Pu and 241 Am were determined for each layer of sediment

  14. Sedimentation of Cobalt-60 and Cesium-137 in the bay of Tvaeren 1964-1980

    International Nuclear Information System (INIS)

    Ramberg, L.; Lampe, S.

    1980-11-01

    Since 1964 the Co-60 and Cs-137 radioactivity of the sediments of the Tvaeren bay has been recorded every year at several points. Changes have been analysed in relation to atmospheric fallout releases from Studsvik distance from release point and depth. Estimates of total quantity for both nuclides bound up in the sediments and a forecast of future trends are presented. Sedimentation coefficients have been calculated and the factors which govern the degree of sedimentation are discussed.(G.B.)

  15. Multielemental analysis of surface sediments in Havana bay (Cuba) using X-ray fluorescence

    International Nuclear Information System (INIS)

    Gelen, A.; Corrales, Y.; Lopez, N.; Manso Guevara, M. V.; Casanova, A. O.; Alessandro, K. D'; Diaz, O.; Espen, P. Van; Beltran, J.; Soto, J.

    2006-01-01

    Multielemental Analysis was performed in Superficial Sediments in Havana Bay. Twenty one samples were analysed by Dispersive Energy X- Ray Fluorescence using an spectrometer based on Si (Li) semiconductor detector an a 109 Cd source. The results showed a similar behaviour in the levels of contamination related with neutron activation analysis. The data suggest that an anthropogenic input into the bay from domestic sewage and industries occurred. (Full text)

  16. Enhanced particle fluxes in Bay of Bengal inducEd. by injection of freshwater

    Digital Repository Service at National Institute of Oceanography (India)

    Ittekkot, V.; Nair, R.R.; Honjo, S.; Ramaswamy, V.; Bartsch, M.; Manganini, S.J.; Desai, B.N.

    deployed three sediment-trap moorings (two traps in each mooring) in the northern, central and southern parts of the Bay of Bengal, respectively. The Bay of Bengal is suitable for such a study, because some of the world's largest rivers supply pulses...

  17. Paleomagnetic investigation of late Quaternary sediments of south San Francisco Bay, California

    Science.gov (United States)

    Hillhouse, John W.

    1977-01-01

    Paleomagnetic inclinations of the Late Quaternary sediments of South San Francisco Bay were determined from bore hole samples collected near Dumbarton Bridge. The sediments consist of estuarine muds and nonmarine sand deposits, floored by bedrock of the Mesozoic Franciscan Formation. - Beneath Dumbarton Bridge the entire sedimentary fill is normally polarized; therefore, the fill postdates the Brunhes-Matayama polarity reversal (700,000 y. B.P.). Magnetic time lines such as the Mono Lake excursion (24,000 y. B.P.) and the reversed Blake event (110,000 y B.P.) were not found in this bore hole. In addition to Holocene and modern deposits of San Francisco Bay, an older estuarine unit occurs in the stratigraphic section. The older unit was deposited during a period of high sea level, tentatively correlated with the Sangamon interglacial period. Because evidence of the Blake event is not present in the older estuarine unit, the proposed age of this unit could not be confirmed. Although the Holocene estuarine deposits of South San Francisco Bay carry stable remanent magnetization, a reliable record of geomagnetic secular variation could not be recovered because the water-saturated sdiment was deformed by drilling.

  18. 137Cs in marine sediments of Admiralty Bay, King George Island, Antarctica

    International Nuclear Information System (INIS)

    Ferreira, Paulo Alves de Lima; Ribeiro, Andreza Portella; Nascimento, Mylene Giseli do; Martins, Cesar de Castro; Mahiques, Michel Michaelovitch de; Montone, Rosalinda Carmelo; Figueira, Rubens Cesar Lopes

    2013-01-01

    The radionuclide cesium-137 ( 137 Cs) is produced exclusively by anthropogenic processes and primarily by nuclear explosions. This study determined the reference inventory that is 137 Cs associated with the element's original input, and utilized the levels of activity of this radionuclide previously measured in five sediment profiles collected from Admiralty Bay, Antarctica, to investigate the mobility of this element in the environment. 137 Cs has a half-life of 30 years. Because of this, it is environmentally persistent and has been shown to accumulate in marine organisms. The mean reference inventory of this radionuclide in Admiralty Bay sediments, determined using high resolution gamma ray spectrometry, was 20.23 ± 8.94 Bq m −2 , and within the ambient 137 Cs activity range. A model of 137 Cs diffusion–convection was applied to data collected from 1 cm intervals in sediment cores with the aim of providing insights with respect to this element's behavior in sediments. Model results showed a significant correlation between measured and modeled values using the concentrations of 137 Cs, and estimated input into the system from the global fallout of past nuclear tests and expected values based on local sedimentation rates. Results highlight the importance of accounting for the vertical diffusion of 137 Cs in marine sediments when used as a tracer for environmental processes and for assessing potential bioavailability. - Highlights: ► Cesium-137 ( 137 Cs) is produced exclusively by anthropogenic processes. ► A model of diffusion–convection simulated 137 Cs environmental behavior. ► This is important for assessing the bioavailability of this toxic element. ► In Antarctica ice cover influenced the input to the sediments

  19. Sustainable development in the Hudson Bay/James Bay bioregion

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    An overview is presented of projects planned for the James Bay/Hudson Bay region, and the expected environmental impacts of these projects. The watershed of James Bay and Hudson Bay covers well over one third of Canada, from southern Alberta to central Ontario to Baffin Island, as well as parts of north Dakota and Minnesota in the U.S.A. Hydroelectric power developments that change the timing and rate of flow of fresh water may cause changes in the nature and duration of ice cover, habitats of marine mammals, fish and migratory birds, currents into and out of Hudson Bay/James Bay, seasonal and annual loads of sediments and nutrients to marine ecosystems, and anadromous fish populations. Hydroelectric projects are proposed for the region by Quebec, Ontario and Manitoba. In January 1992, the Canadian Arctic Resources Committee (CARC), the Environmental Committee of Sanikuluaq, and the Rawson Academy of Arctic Science will launch the Hudson Bay/James Bay Bioregion Program, an independent initiative to apply an ecosystem approach to the region. Two main objectives are to provide a comprehensive assessment of the cumulative impacts of human activities on the marine and freshwater ecosystems of the Hudson Bay/James Bay bioregion, and to foster sustainable development by examining and proposing cooperative processes for decision making among governments, developers, aboriginal peoples and other stakeholders. 1 fig

  20. [Surface Property and Sorption Characteristics of Phosphorus onto Surface Sediments in Sanggou Bay].

    Science.gov (United States)

    Zhu, Jia-mei; Cao, Xiao-yan; Liu, Su-mei; Wang, Li-sha; Yang, Gui-peng; Ge, Cheng-feng; Lu, Min

    2016-02-15

    Kinetic curves and isotherms were investigated to study the sorption mechanism of phosphorus onto the sediments of Sanggou Bay, together with the surface charge properties of sediments and the forms of phosphorus studied. The results showed that the sorption including a fast process and a slow one, and could be described by a two-compartment first order equation. The thermodynamic isotherms were well fitted with a modified Langmuir equation. The maximum adsorption capacity was larger in summer than in spring, and the smaller particle size was favorable to the sorption. The maximum adsorption capacities (Qm) were 0.0471-0.1230 mg x g(-1), and the zero equilibrium phosphorus concentration (EPC0) of the sediments ranged from 0.0596 mg x L(-1) to 0.1927 mg x L(-1), which indicated that the sediments from Sanggou Bay were sources of phosphorus. Inorganic phosphorus (IP) was the main form of total phosphorus (TP). The contents of exchangeable or loosely absorbed P and Fe-bound P increased significantly in the samples after sorption. The sorption process involved physical sorption and chemical sorption, with the former being the predominant.

  1. 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.

  2. Seismic stratigraphy and late Quaternary shelf history, south-central Monterey Bay, California

    Science.gov (United States)

    Chin, J.L.; Clifton, H.E.; Mullins, H.T.

    1988-01-01

    The south-central Monterey Bay shelf is a high-energy, wave-dominated, tectonically active coastal region on the central California continental margin. A prominent feature of this shelf is a sediment lobe off the mouth of the Salinas River that has surface expression. High-resolution seismic-reflection profiles reveal that an angular unconformity (Quaternary?) underlies the entire shelf and separates undeformed strata above it from deformed strata below it. The Salinas River lobe is a convex bulge on the shelf covering an area of approximately 72 km2 in water depths from 10 to 90 m. It reaches a maximum thickness of 35 m about 2.5 km seaward of the river mouth and thins in all directions away from this point. Adjacent shelf areas are characterized by only a thin (2 to 5 m thick) and uniform veneer of sediment. Acoustic stratigraphy of the lobe is complex and is characterized by at least three unconformity-bounded depositional sequences. Acoustically, these sequences are relatively well bedded. Acoustic foresets occur within the intermediate sequence and dip seaward at 0.7?? to 2.0??. Comparison with sedimentary sequences in uplifted onshore Pleistocene marine-terrace deposits of the Monterey Bay area, which were presumably formed in a similar setting under similar processes, suggests that a general interpretation can be formulated for seismic stratigraphic patterns. Depositional sequences are interpreted to represent shallowing-upwards progradational sequences of marine to nonmarine coastal deposits formed during interglacial highstands and/or during early stages of falling sea level. Acoustic foresets within the intermediate sequence are evidence of seaward progradation. Acoustic unconformities that separate depositional sequences are interpreted as having formed largely by shoreface planation and may be the only record of the intervening transgressions. The internal stratigraphy of the Salinas River lobe thus suggests that at least several late Quaternary

  3. Sources of suspended-sediment flux in streams of the chesapeake bay watershed: A regional application of the sparrow model

    Science.gov (United States)

    Brakebill, J.W.; Ator, S.W.; Schwarz, G.E.

    2010-01-01

    We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According to our model, urban development generates on average the greatest amount of suspended sediment per unit area (3,928 Mg/km2/year), although agriculture is much more widespread and is the greatest overall source of suspended sediment (57 Mg/km2/year). Factors affecting sediment transport from uplands to streams include mean basin slope, reservoirs, physiography, and soil permeability. On average, 59% of upland suspended sediment generated is temporarily stored along large rivers draining the Coastal Plain or in reservoirs throughout the watershed. Applying erosion and sediment controls from agriculture and urban development in areas of the northern Piedmont close to the upper Bay, where the combined effects of watershed characteristics on sediment transport have the greatest influence may be most helpful in mitigating sedimentation in the bay and its tributaries. Stream restoration efforts addressing floodplain and bank stabilization and incision may be more effective in smaller, headwater streams outside of the Coastal Plain. ?? 2010 American Water Resources Association. No claim to original U.S. government works.

  4. Recent 137Cs deposition in sediments of Admiralty Bay, Antarctica

    International Nuclear Information System (INIS)

    Sanders, Christian J.; Santos, Isaac R.; Patchineelam, Sambasiva R.; Schaefer, Carlos; Silva-Filho, Emmanoel V.

    2010-01-01

    Cesium-137, radium-226 and lead-210 profiles of a 25 cm sediment core give an indication of recent changes in land-ocean interactions at a polar coastal environment (Admiralty Bay, King George Island, Antarctica). The linear sedimentation accumulation rate at the study site calculated from the unsupported 210 Pb profile was 6.7 mm/year from 1965 to 2005. A 3.5-fold increase in 137 Cs concentrations was observed in the top layer of this sediment core. This sharp increase seems to indicate a recent redistribution of fallout radionuclides previously deposited on soil, vegetation and snow. These results imply enhanced land-ocean interactions at this site likely as a result of climate change. Because our results are based on a single core, additional investigations are needed to confirm our observations.

  5. Potential sources of hydrogel stabilization of Florida Bay lime mud sediments and implications for organic matter preservation

    Science.gov (United States)

    Louda, J.W.; Loitz, J.W.; Melisiotis, A.; Orem, W.H.

    2004-01-01

    The fine grained carbonate mud sediments of central Florida Bay are resuspended quite easily. However, this disturbance is usually limited to the surficial ('floc') layer, as the underlying sediments appear to be stabilized by an hydrogelation involving the bulk organic matter. That gelation has occurred within these sediments is suggested from their physical behavior and an observed mathematical relationship between the percentages of organic carbon (C org) and water. Specifically, when extruded from a core barrel, the sediment maintains its integrity and has the consistency of a fine spackling compound. However, upon homogenization, as with a stirring rod prior to sieving, these sediments break into two distinct phases, 1/2-2/3 milky water and 1/3-1/2 sediment grains, by volume. The relationship observed between Corg and water was modeled as both linear (% water = (0.0777) Corg + 0.2984, R2 = 0.8664) and logarithmic (% water = 0.2489 Ln Corg + 0.2842, R2 = 0.9455) functions. As this relationship tends to be asymptotic at higher Corg (>3.5% dry)/water values (>60%) and given an higher correlation, the relationship appears better modeled as a logarithmic function. Values of C org from 1.2 to over 6.5%dry wt. and water contents from 30 to over 70%wt. were observed. The calculated intercept revealed that, without organic carbon (viz. hydrogel formation), these carbonates would likely contain only ???30% water by weight ('m' from linear model). This gelation is proposed to involve exopolymeric substances (EPS), likely polysaccharides, derived from diatoms and cyanobacteria of the microphytobenthos. A cyanobacterial-diatomaceous biofilm/mat underlain by purple sulfur bacteria was shown, by pigment based chemotaxonomy, to form the main components of the microphytobenthos. Additional water column detrital biomass, also mainly cyanobacteria and diatoms, is admixed with the living microphytobenthos in a flocculent/nephloid layer above the sediments prior to final

  6. Tracking polychlorinated biphenyls (PCBs) congener patterns in Newark Bay surface sediment using principal component analysis (PCA) and positive matrix factorization (PMF).

    Science.gov (United States)

    Saba, Tarek; Su, Steave

    2013-09-15

    PCB congener data for Newark Bay surface sediments were analyzed using PCA and PMF, and relationships between the outcomes from these two techniques were explored. The PCA scores plot separated the Lower Passaic River Mouth samples from North Newark Bay, thus indicating dissimilarity. Although PCA was able to identify subareas in the Bay system with specific PCB congener patterns (e.g., higher chlorinated congeners in Elizabeth River), further conclusions reading potential PCB source profiles or potential upland source areas were not clear for the PCA scores plot. PMF identified five source factors, and explained the Bay sample congener profiles as a mix of these Factors. This PMF solution was equivalent to (1) defining an envelope that encompasses all samples on the PCA scores plot, (2) defining source factors that plot on that envelope, and (3) explaining the congener profile for each Bay sediment sample (inside the scores plot envelope) as a mix of factors. PMF analysis allowed identifying characteristic features in the source factor congener distributions that allowed tracking of source factors to shoreline areas where PCB inputs to the Bay may have originated. The combined analysis from PCA and PMF showed that direct discharges to the Bay are likely the dominant sources of PCBs to the sediment. Review of historical upland activities and regulatory files will be needed, in addition to the PCA and PMF analysis, to fully reconstruct the history of operations and PCB releases around the Newark Bay area that impacted the Bay sediment. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Lithogenic fluxes in the Bay of Bengal measured by sediment traps

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaswamy, V.; VijayKumar, B.; Parthiban, G.; Ittekkot, V.; Nair, R.R.

    -Sea Research I, Vol. 44, No. 5, pp. 793410, 1997 0 1997 Elsevier Science Ltd PII: S0967-0637(96)00117-3 All tights reserved. Printed in Great Britain 09674x37/97 917.00+0.00 Lithogenic fluxes in the Bay of Bengal measured by sediment traps V. RAMASWAMY,* B... of amorphous silica in marine sediments. Journal of Sedimentary Petrology, 50, 215-225. Emmel, F. J. and Curray, J. R. (1984) The Bengal submarine fan, northeastern Indian Ocean. Geo-Marine Letters, 3, 119-124. Goldberg, E. D. and Griffin, J. J. (1970...

  8. Plutonium characteristics in sediments of Hiroshima Bay in the Seto Inland Sea in Japan

    International Nuclear Information System (INIS)

    Zhiyong Liu; National Institute of Radiological Sciences, Chiba; Jian Zheng; Masatoshi Yamada; Hirosaki University, Hirosaki, Aomori; Shaoming Pan; Hodaka Kawahata

    2011-01-01

    Sediment core samples were collected from Hiroshima Bay in the Seto Inland Sea, western Northwest Pacific Ocean, and their 239+240 Pu activities and 240 Pu/ 239 Pu atom ratios were determined by sector field ICP-MS. The activities of 239+240 Pu ranged from 0.556 ± 0.025 to 0.745 ± 0.023 mBq/g. The atom ratios of 240 Pu/ 239 Pu were almost constant within the whole depth; the average value was 0.227 ± 0.014. This atom ratio was significantly higher than the mean global fallout ratio of 0.18, proving the presence of close-in fallout Pu that originated from the Pacific Proving Ground (PPG). The water masses exchanges between the Kuroshio Current and the Seto Inland Sea brought the PPG source Pu to this area, then Pu was extensively scavenged into sediment particles supplied by the rivers around the bay. The relative contributions of the global fallout Pu and the PPG close-in fallout Pu were evaluated by the two end-member mixing model. The contribution of the PPG close-in fallout was 38-41% of the total Pu in sediment. The remaining 59-62% was attributed to direct global fallout and the land-origin Pu transported by the rivers around the Hiroshima Bay. (author)

  9. Petroleum Hydrocarbon Profiles of Water and Sediment of Algoa Bay, Eastern Cape, South Africa

    Directory of Open Access Journals (Sweden)

    Abiodun O. Adeniji

    2017-10-01

    Full Text Available Petroleum hydrocarbon profiles of water and sediment samples of Algoa Bay in the Eastern Cape Province of South Africa were assessed using standard analytical procedures. Water (from surface and bottom levels and sediment samples were collected from five locations in the bay from February to June 2016. Extraction of the petroleum hydrocarbons from the water and sediment samples collected was achieved using liquid-liquid and Soxhlet extraction techniques, respectively, followed by column clean up. Target compounds were analytically determined with gas chromatography–flame ionization detector (GC-FID and quantified by integrating the areas of both the resolved and unresolved components. Physicochemical properties of the water samples were also determined on site using a SeaBird 19plusV2 CTD SBE 55 device. Estimated limit of detection, limit of quantitation and relative standard deviation for the 35 n-alkane standards ranged from 0.06 to 0.13 μg/L, 0.30 to 0.69 μg/L and 3.61 to 8.32%, respectively. Results showed that total petroleum hydrocarbon (TPH varied from 45.07 to 307 μg/L in the water and 0.72 to 27.03 mg/kg in the sediments. The mean concentrations of TPH in both the water and sediment samples from Algoa Bay revealed a slight level of pollution. The diagnostic indices used showed that the hydrocarbons in the area were from both biogenic and anthropogenic sources. Hence, there is need for adequate regulation and control of all activities contributing to the levels of petroleum hydrocarbon in the marine environment for the safety of human, aquatic and wild lives in the area.

  10. Petroleum Hydrocarbon Profiles of Water and Sediment of Algoa Bay, Eastern Cape, South Africa.

    Science.gov (United States)

    Adeniji, Abiodun O; Okoh, Omobola O; Okoh, Anthony I

    2017-10-20

    Petroleum hydrocarbon profiles of water and sediment samples of Algoa Bay in the Eastern Cape Province of South Africa were assessed using standard analytical procedures. Water (from surface and bottom levels) and sediment samples were collected from five locations in the bay from February to June 2016. Extraction of the petroleum hydrocarbons from the water and sediment samples collected was achieved using liquid-liquid and Soxhlet extraction techniques, respectively, followed by column clean up. Target compounds were analytically determined with gas chromatography-flame ionization detector (GC-FID) and quantified by integrating the areas of both the resolved and unresolved components. Physicochemical properties of the water samples were also determined on site using a SeaBird 19plusV2 CTD SBE 55 device. Estimated limit of detection, limit of quantitation and relative standard deviation for the 35 n -alkane standards ranged from 0.06 to 0.13 μg/L, 0.30 to 0.69 μg/L and 3.61 to 8.32%, respectively. Results showed that total petroleum hydrocarbon (TPH) varied from 45.07 to 307 μg/L in the water and 0.72 to 27.03 mg/kg in the sediments. The mean concentrations of TPH in both the water and sediment samples from Algoa Bay revealed a slight level of pollution. The diagnostic indices used showed that the hydrocarbons in the area were from both biogenic and anthropogenic sources. Hence, there is need for adequate regulation and control of all activities contributing to the levels of petroleum hydrocarbon in the marine environment for the safety of human, aquatic and wild lives in the area.

  11. Characterization of trace organic contaminants in marine sediment from Yeongil Bay, Korea: 2. Dioxin-like and estrogenic activities

    International Nuclear Information System (INIS)

    Koh, Chul-Hwan; Khim, Jong Seong; Villeneuve, Daniel L.; Kannan, Kurunthachalam; Giesy, John P.

    2006-01-01

    This study employed mechanism-specific in vitro bioassays to help characterize the occurrence and distribution of dioxin-like and estrogenic contaminants in sediment from Yeongil Bay, Korea. Approximately 85% of the sediments tested induced significant dioxin-like activity in the H4IIE-luc bioassay, while approximately 50% induced significant estrogenic activity in the MVLN bioassay. Instrumentally-derived estimates of 2,3,7,8-tetrachlorodibenzo-p-dioxin and 17β-estradiol equivalents tended to underestimate the magnitude of response observed in the bioassays, suggesting that compounds detected by chemical analysis did not account for all the activity associated with Yeongil Bay sediments, or that non-additive interactions were occurring. The greatest dioxin-like and estrogenic activity was associated with the mid-polarity Florisil fractions (F2) expected to contain polycyclic aromatic hydrocarbons (PAHs) as well as chlorinated dioxins and furans. As in previous studies of Korean coastal sediment, more polar fractions (F3) generated more modest responses both in terms of magnitude and the number of samples responding. -- In vitro bioassay responses observed for Yeongil Bay surficial sediment and sediment core extracts showed the greatest dioxin-like and estrogenic activities in the mid-polarity fraction containing PAHs as well as chlorinated dioxins and furans

  12. Metal and trace elements assessment in sediments of Kakinada Bay, East Coast India, by INAA and PIXE

    International Nuclear Information System (INIS)

    Dasari, K.B.; Ratna Raju, M.; Lakshminarayana, S.; Naidu, T.Y.; Raju, V.S.

    2012-01-01

    Aquatic sediment is more homogeneous in grain-size (< 0.06 mm) distribution, and the fine particles are more capable of adsorbing pollutants than coarser fractions. Aquatic mediums are the receipt of the liquid effluents of the variety of industries, atmosphere changes and anthropogenic processes. Godavari river is one of the most important rivers in India and which is adjoining coast into the Bay of Bengal near Kakinada. The study area viz. Kakinada Bay (Godavari delta) rich in industries, appears to be fragile with thick pile of sediments dipping towards sea and underlain by faults. Hence any change in existing equilibrium would affect aquatic ecosystem. The objective of this study is to quantify the amount of trace, heavy metals ions present in sediments collected from Kakinada Bay, Andhra Pradesh, India. Five sites were selected along the coastal area covering the important potential pollutions sources at Godavari delta. Instrumental neutron activation analysis and particle induced X-ray emission techniques were carried out for trace and some metals determination

  13. Quantitative research for pollution levels in marine sediments of Ha Long Bay by nuclear technique

    International Nuclear Information System (INIS)

    Nguyen Quang Long; Tran Thi Tuyet Mai; Pham Ngoc Khai; Nguyen Trung Thanh; Nguyen Van Phuc; Doan Thuy Hau; Duong Van Thang; Ha Lan Anh; Vo Thi Anh; Nguyen Thi Thu Ha

    2013-01-01

    Under the theme of Quantitative study of pollution levels in marine sediments of Halong bay by nuclear techniques conducted from June 2011 to June 2013, the authors conducted monitoring, sediment samples collected in the bay below the sediment column at 8 locations, in which 7 columns located at the estuary near Tuan Chau Island and 1 column at the area near the harbor of Cam Pha. The column samples were taken to the laboratory, cut slices with a distance of 2 cm in the form of frozen and conduct tests of radioactive Pb-210 to determine the rate of sediment in the survey area. Evaluation results based on the method by determining 210 Pb, the sediment rate showed speed in the survey area ranged from 0.3 cm.a -1 to 1.2 cm.a -1 and an average of 1.0 cm.a -1 . The slices of sediment samples (110 samples) were analyzed heavy metals (KLN) and As elemental by ICP-MS method. These sediment sample also were analyzed for simultaneous determination of N and P and total organic carbon (TOC). Results showed that heavy metal concentrations and As is smaller than the value specified in the National Technical Regulation on Sediment Quality of Vietnam (QCVN), phosphorus concentration less than that can cause harmful effects, but the concentration of total nitrogen and organic carbon that may exceed be harmful as directed by Canadian standards (Persuad et al. 1992). The concentration data in the Halong bay sediment were processed by statistical software SPSS-18, results showed high correlation between the quality TOC, N, P, K and correlation the majority of KLN, this proves the origin of sediments is part of the natural soil components and parts (TOC, N, P, K) is due to the activity of human activity as well as by agricultural fertilizers. The average content of elements in sediments Halong be compared with other data published works of sediment Quang Ninh area, the results show the correlation figures are also high. However, the results of the analysis of KLN and As in Halong

  14. Characterization of organic matter in sediment cores of the Todos os Santos Bay, Bahia, Brazil, by elemental analysis and 13C NMR

    International Nuclear Information System (INIS)

    Costa, A.B.; Novotny, E.H.; Bloise, A.C.; Azevedo, E.R. de; Bonagamba, T.J.; Zucchi, M.R.; Santos, V.L.C.S.; Azevedo, A.E.G.

    2011-01-01

    Highlights: → The impact of human activity on the sediments of Todos os Santos Bay in Brazil was evaluated by EA and 13 C NMR. → This article reports a study of six sediment cores collected at different depths and regions. → The elemental profiles of cores suggest an abrupt change in the sedimentation regime, corresponds to about 50 years ago, coinciding with the implantation of major onshore industrial projects. → The results presented illustrate several important aspects of environmental impact of human activity on this bay. - Abstract: The impact of human activity on the sediments of Todos os Santos Bay in Brazil was evaluated by elemental analysis and 13 C Nuclear Magnetic Resonance ( 13 C NMR). This article reports a study of six sediment cores collected at different depths and regions of Todos os Santos Bay. The elemental profiles of cores collected on the eastern side of Frades Island suggest an abrupt change in the sedimentation regime. Autoregressive Integrated Moving Average (ARIMA) analysis corroborates this result. The range of depths of the cores corresponds to about 50 years ago, coinciding with the implantation of major onshore industrial projects in the region. Principal Component Analysis of the 13 C NMR spectra clearly differentiates sediment samples closer to the Subae estuary, which have high contents of terrestrial organic matter, from those closer to a local oil refinery. The results presented in this article illustrate several important aspects of environmental impact of human activity on this bay.

  15. Study of recent changes in sedimentation regime inside Cienfuegos Cuban bay, using 210Pb and 137Cs as tracers

    International Nuclear Information System (INIS)

    Alonso Hernandez, C.M.; Diaz Asencio, M.; Munnoz Caravaca, A.; Delfanti, R.; Papucci, C.

    2001-01-01

    Cienfuegos Bay is a semi closed bay with a surface area of 90 km2 and an average depth of 14m, connected to the Caribbean Sea by a narrow channel of about 3 km long. The bay is divided in two well defined hydro graphic cells, due to the presence of a submerged ridge about 1m below the water surface. The northern cell receives most of the anthropic impact from the outfall of Cienfuegos city, industrial pole in the country, and the fluvial supply of Damuji and Salado rivers. The southern cell receives a lower anthropic impact from the Caonao and Arimao river inputs. Part of this southern cell is a natural protected park, which represents a niche of migratory birds and marine species in conservation status.The bay represents the most important natural resource in the province, due to fishing activities, maritime transport, tourism industry, and natural parks. In the last three decades, deleterious ecological signers in the area have been observed. Declining of biodiversity in the ecosystem, bethonic communities' movement, reduction of size and capture levels of commercial marine species, erosion of coastline, could be associated with changes of sedimentation regime in the bay. The distribution of 210Pb, 137Cs in sediments provide, insight into the sedimentation processes in the last 100 years. The main goal of the present study was the application of 210Pb, 137Cs dating techniques to estimate the recent sedimentation rates in the bay. Two sediment cores, (S and N) have been collected in 1999 using a gravity corer. The lengths of the cores were 0.93m. The cores were extruded and sliced immediately in 1.5cm intervals. Aliquots of 5g of each core sections were used for complementary analyses. The remaining parts were dried and placed in standard geometry for the determination of 210Pb and 137Cs activities, by g spectrometry with an hyper pure Germanium detector coupled with multichannel analyzer. Both core profiles show that important environmental changes have been

  16. Distribution of some biochemical compounds in the sediments of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Dhople, V.M.

    Surficial sediment samples collected from the continental shelf and slope of the Bay of Bengal were studied for the distribution of organic carbon and its constituent fractions such as carbohydrates, proteins, amino acids and lipids. Organic carbon...

  17. Understanding processes controlling sediment transports at the mouth of a highly energetic inlet system (San Francisco Bay, CA)

    Science.gov (United States)

    Elias, Edwin P.L.; Hansen, Jeff E.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    San Francisco Bay is one of the largest estuaries along the U.S. West Coast and is linked to the Pacific Ocean through the Golden Gate, a 100 m deep bedrock inlet. A coupled wave, flow and sediment transport model is used to quantify the sediment linkages between San Francisco Bay, the Golden Gate, and the adjacent open coast. Flow and sediment transport processes are investigated using an ensemble average of 24 climatologically derived wave cases and a 24.8 h representative tidal cycle. The model simulations show that within the inlet, flow and sediment transport is tidally dominated and driven by asymmetry of the ebb and flood tides. Peak ebb velocities exceed the peak flood velocities in the narrow Golden Gate channel as a result of flow convergence and acceleration. Persistent flow and sediment gyres at the headland tips are formed that limit sediment transfer from the ebb-tidal delta to the inlet and into the bay. The residual transport pattern in the inlet is dominated by a lateral segregation with a large ebb-dominant sediment transport (and flow) prevailing along the deeper north side of the Golden Gate channel, and smaller flood dominant transports along the shallow southern margin. The seaward edge of the ebb-tidal delta largely corresponds to the seaward extent of strong tidal flows. On the ebb-tidal delta, both waves and tidal forcing govern flow and sediment transport. Wave focusing by the ebb-tidal delta leads to strong patterns of sediment convergence and divergence along the adjacent Ocean Beach.

  18. Distribution of clay minerals in marine sediments off Chennai, Bay of Bengal, India: Indicators of sediment sources and transport processes .

    Digital Repository Service at National Institute of Oceanography (India)

    Veerasingam, S.; Venkatachalapathy, R.; Ramkumar, T.

    Clay mineralogy, texture size and statistical analyses were carried out on surface sediments from the continental shelf of Chennai, Bay of Bengal, India. The purpose of this study is to characterize the clay mineral distribution and its relation...

  19. Difference of nitrogen-cycling microbes between shallow bay and deep-sea sediments in the South China Sea.

    Science.gov (United States)

    Yu, Tiantian; Li, Meng; Niu, Mingyang; Fan, Xibei; Liang, Wenyue; Wang, Fengping

    2018-01-01

    In marine sediments, microorganisms are known to play important roles in nitrogen cycling; however, the composition and quantity of microbes taking part in each process of nitrogen cycling are currently unclear. In this study, two different types of marine sediment samples (shallow bay and deep-sea sediments) in the South China Sea (SCS) were selected to investigate the microbial community involved in nitrogen cycling. The abundance and composition of prokaryotes and seven key functional genes involved in five processes of the nitrogen cycle [nitrogen fixation, nitrification, denitrification, dissimilatory nitrate reduction to ammonium (DNRA), and anaerobic ammonia oxidation (anammox)] were presented. The results showed that a higher abundance of denitrifiers was detected in shallow bay sediments, while a higher abundance of microbes involved in ammonia oxidation, anammox, and DNRA was found in the deep-sea sediments. Moreover, phylogenetic differentiation of bacterial amoA, nirS, nosZ, and nrfA sequences between the two types of sediments was also presented, suggesting environmental selection of microbes with the same geochemical functions but varying physiological properties.

  20. Palaeoclimatic significance of gypsum pseudomorphs in the inner shelf sediments off Machalipatnam bay

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.

    Pseudo-gypsum crystals have been found in the coarse fraction of the sediments from the inner continental shelf off Machilipatnam Bay. They range in size from 3 to 7 mm are elongate and lenticular in shape. Bassanite and calcite are pseudomorphs...

  1. Determination of sedimentation rates in Izmir Bay by 210Pb dating technique

    International Nuclear Information System (INIS)

    Ichedef, M.; Yener, G.; Ugur, A.; Oezden, B.; Goenuelalan, F.; Akoezcan, S.; Bueyuekisik, B.; Koeksal, E. Y.

    2006-01-01

    Environmental 2 10Pb (natural) dating technique was applied to determine sedimentation rates in Izmir Bay, near the heavily industrialized Turkish Coastal zone of the Aegean Sea. Core samples from different 20 stations in the inner bay were collected with core sampler and sedimentation rates were estimated from the vertical distribution of excess 2 10Pb. Core samples were stored for a period of 2-3 half-lives (9-14 months) of 2 10Po (t 1 /2=138 d) before analysis to allow build-up of 2 10Po from 2 10Pb. Po was collected on cupper disks by electrochemical deposition. Then, 2 10Pb activities were determined undirectly from 2 10Po activities. Measurement of 2 10Po were made through its 5.30 MeV alpha particle emission, using 2 09Po as the internal tracer. Measurements were made by PIPS (Passivated Implanted Planar Silicon) detector. The sedimentation rates for core samples analysed so far were calculated to vary from 0.198 cm y - 1 to 0.489 cm y - 1. The highest unsupported 2 10Pb concentrations (104 Bq kg - 1) were measured in the 8.station where the Ilica, Bayrakli and Bornova streams empty, and nearest to the harbour

  2. Microbial diversity and ecotoxicity of sediments 3 years after the Jiaozhou Bay oil spill.

    Science.gov (United States)

    Gao, Wei; Yin, Xiaofei; Mi, Tiezhu; Zhang, Yiran; Lin, Faxiang; Han, Bin; Zhao, Xilong; Luan, Xiao; Cui, Zhisong; Zheng, Li

    2018-05-09

    In 2013, the "Qingdao oil pipeline explosion" released an estimated 2000 tons of oil into the environment. Sediment samples were collected from ten sites in Jiaozhou Bay and Shilaoren Beach to evaluate the influence of the spilled oil on the benthic environment 3 years after the oil spill accident. The compositions of oil, bacterial diversity and biotoxicity were examined in this study. The results showed that the concentration of total petroleum hydrocarbons (TPHs) peaked near the oil leak point and gradually decreased along the coastline, ranging from 21.5 to 133.2 μg/g. The distribution of polycyclic aromatic hydrocarbons (PAHs) was correlated with TPH, and naphthalenes were dominant in the 20 detected PAHs. The bacterial diversities in seriously polluted and slightly polluted sediments were completely different. As degrading bacteria, Alcanivorax and Lutibacter were the main genera at the oil-polluted sites. The analysis of biotoxicity by the luminescent bacteria method showed great differences among the polluted sites, the control site in Jiaozhou Bay, and the non-polluted site outside of Jiaozhou Bay. The biotoxicity also peaked at the site near the oil leak point. These results indicate that the oil spill that occurred 3 years ago still affects the environment and impacts the bacterial communities in the sediments.

  3. Ambient water and sediment quality of Galveston Bay: Present status and historical trends. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ward, G.H.; Armstrong, N.E.

    1992-08-01

    For many years, data relating to the quality of water and sediment have been collected in the Galveston Bay system by a variety of organizations and individuals. The purpose of the project was to compile these data, and to perform a quantitative assessment of water and sediment quality of Galveston Bay and its evolution over time. The study focused on the following categories of parameters: temperature, salinity and related parameters, suspended sediments and turbidity, pH, dissolved oxygen, nutrients as measured by nitrogen, phosphorous and organic carbon, organics as measured by oil and grease, volatile solids and biochemical oxygen demand, chlorophyll-a, coliforms, metals (total and dissolved), and trace organics, including pesticides, herbicides, PAH's, PCB's, and priority pollutants.

  4. Steroid markers to assess sewage and other sources of organic contaminants in surface sediments of Cienfuegos Bay, Cuba.

    Science.gov (United States)

    Tolosa, I; Mesa, M; Alonso-Hernandez, C M

    2014-09-15

    Analyses of faecal steroids in coastal sediments from Cienfuegos Bay Cuba indicate chronic sewage contamination at the main outfalls from the city, where concentrations of coprostanol up to 5400ngg(-)(1) (dry wt) were measured. In contrast, steroid concentrations and compositions from sites from the south part of the Bay are characteristic of uncontaminated sewage environments. The levels of coprostanol in the Cienfuegos sediments compares to the lower to mid-range of concentrations reported for coastal sediments on a world-wide basis, with sedimentary levels markedly below those previously reported for heavily impacted sites. This study delivers baseline data for further investigation of the effectiveness of the proposed sewerage plan promoted by the GEF project in Cienfuegos. Investigations on the correlations between faecal steroids and other organic contaminants confirmed that the major source of petroleum hydrocarbons within the bay was associated with the sewage effluents from the Cienfuegos city. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Source identification of heavy metal contamination using metal association and Pb isotopes in Ulsan Bay sediments, East Sea, Korea

    International Nuclear Information System (INIS)

    Chae, Jung Sun; Choi, Man Sik; Song, Yun Ho; Um, In Kwon; Kim, Jae Gon

    2014-01-01

    Highlights: • The levels of Cu, Zn, and Pb in sediments were higher than the Korean TEL at one-third of all sites. • The primary source of metal contamination came from activities related to nonferrous metal refineries near Onsan Harbor. • Three different anthropogenic sources and background sediments could be identified as endmembers using Pb isotopes. • The major anthropogenic Pb sources were identified as imported ores from Australia and Peru. • Isotope ratios in anthropogenic Pb discharged from Ulsan Bay to offshore could be identified. - Abstract: To determine the characteristics of metal pollution sources in Ulsan Bay, East Sea, 39 surface and nine core sediments were collected within the bay and offshore area, and analyzed for metals and stable lead (Pb) isotopes. Most surface sediments (>95% from 48 sites) had high copper (Cu), zinc (Zn), cadmium (Cd), and Pb concentrations that were as much as 1.3 times higher than background values. The primary source of metal contamination came from activities related to nonferrous metal refineries near Onsan Harbor, and the next largest source was from shipbuilding companies located at the mouth of the Taehwa River. Three different anthropogenic sources and background sediments could be identified as end-members using Pb isotopes. Isotopic ratios for the anthropogenic Pb revealed that the sources were imported ores from Australia, Peru, and the United States. In addition, Pb isotopes of anthropogenic Pb discharged from Ulsan Bay toward offshore could be determined

  6. Acute and chronic toxicity of sediment samples from Guanabara Bay (RJ during the rainy period

    Directory of Open Access Journals (Sweden)

    Luciane Alves Maranho

    2010-06-01

    Full Text Available Guanabara Bay is a marine-estuarine environment of high ecological and socio-economic importance, subject to a variety of environmental impacts. Sediment is the eventual repository for most substances introduced into water bodies and may, therefore, provide an integrated measure of the environmental quality, which can be assessed by many different approaches. In this project, the quality of sediments from Guanabara Bay was evaluated by the ecotoxicological approach: whole-sediment toxicity tests, using Tiburonella viscana, and porewater, elutriate and sediment-water interface chronic toxicity tests, using embryos of Lytechinus variegatus, were applied. Sediments were collected at 14 sampling stations, distributed across the bay. Chronic tests showed significant toxicity in most of the sediment samples. Sediments from stations 1, 2, 3, 6, 8, 10, 11, 12 and 15 showed acute toxicity as well. The results of the different tests were well correlated, and their integration showed that the sediments analyzed were considered unsuitable for aquatic life, resulting in the environmental degradation of Guanabara Bay. In this context, the control of pollution sources and multi-purpose management are required to improve the environmental quality.A Baía de Guanabara é um ambiente marinho-estuarino de grande relevância ecológica e sócio-econômica, e sujeita a uma ampla gama de impactos ambientais. O sedimento é o principal destino para a maioria das substâncias introduzidas nos corpos d'água, podendo fornecer uma medida integrada da qualidade ambiental, a qual pode ser avaliada por várias abordagens. Neste projeto, a qualidade de sedimentos da Baía de Guanabara foi por uma abordagem ecotoxicológica, por meio de testes de toxicidade aguda de sedimento integral, utilizando Tiburonella viscana, e testes de toxicidade crônica de água intersticial, elutriato e interface sedimento-água, utilizando embriões de Lytechinus variegatus. Os sedimentos foram

  7. Magnetic basement in the central Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, K.V.L.N.S.; Ramana, M.V.; Ramprasad, T.; Desa, M.; Subrahmanyam, V.; Krishna, K.S.; Rao, M.M.M.

    Analyses of about 6000 km of processed magnetic data in the central Bay of Bengal using Analytical Signal Processing and Werner Deconvolution techniques revealed that the depth to top of the magnetic basement varies between 5 and 12 km from the sea...

  8. Environmental control on anaerobic oxidation of methane in the gassy sediments of Eckernforde Bay (German Baltic)

    DEFF Research Database (Denmark)

    Treude, T.; Kruger, M.; Boetius, A.

    2005-01-01

    We investigated the effect of seasonal environmental changes on the rate and distribution of anaerobic oxidation of methane (AOM) in Eckernforde Bay sediments (German Baltic Sea) and identified organisms that are likely to be involved in the process. Surface sediments were sampled during September...... of methane were measured in vitro. AOM changed seasonally within the upper 20 cm of the sediment, with rates being between 1 and 14 nmol cm(-3) d(-1). Its distribution is suggested to be controlled by oxygen and sulfate penetration, temperature, as well as methane supply, leading to a shallow AOM zone during...... AOM in Eckerntorde Bay. These archaea are known also from other marine methane-rich locations. However, they were not directly associated with sulfate-reducing bacteria. AOM is possibly mediated solely by these archaea that show a mesophilic physiology according to the seasonal temperature changes...

  9. Trace element distribution in different chemical fractions of False Bay sediments

    International Nuclear Information System (INIS)

    Rosental, R.

    1984-05-01

    Trace metals in the aquatic environment are generally concentrated on solid geochemical phases which eventually become incorporated into estuarine and marine sediments. The mechanism of trace metal concentration is believed to be adsorption on various geochemical phases, such as hydrous metal oxides, clays and organic matter. Metals in estuarine sediments can thus be expected to be partitioned between different phases, depending on the concentration of the phase and the strength of the adsorption bond. The bioavailability of sediment-bound metals to deposit-feeding organisms will depend on trace metal partitioning and the kinetics of biological metal uptake from each geochemical phase. The major objective of this study was to establish an analytical procedure involving sequential chemical extractions for the partitioning of particulate trace metals in sediment samples, collected from False Bay. Eight metals were examined, i.e. Cd, Cu, Cr, Fe, Mn, Ni, Pb and Zn. X-ray diffraction was also used in the study

  10. {sup 137}Cs in marine sediments of Admiralty Bay, King George Island, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Paulo Alves de Lima [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil); Ribeiro, Andreza Portella, E-mail: andrezpr@usp.br [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil); Mestrado de Gestão Ambiental e Sustentabilidade, Universidade Nove de Julho (UNINOVE), Avenida Francisco Matarazzo, 612, prédio C, andar térreo, Água Branca, São Paulo, SP, 05001 100 (Brazil); Nascimento, Mylene Giseli do; Martins, Cesar de Castro [Centro de Estudos do Mar, Universidade Federal do Paraná (CEM-UFPR), Av. Beira-mar, no number, Balneário Pontal do Sul, Pontal do Paraná, PR, 83255 971 (Brazil); Mahiques, Michel Michaelovitch de; Montone, Rosalinda Carmelo; Figueira, Rubens Cesar Lopes [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil)

    2013-01-15

    The radionuclide cesium-137 ({sup 137}Cs) is produced exclusively by anthropogenic processes and primarily by nuclear explosions. This study determined the reference inventory that is {sup 137}Cs associated with the element's original input, and utilized the levels of activity of this radionuclide previously measured in five sediment profiles collected from Admiralty Bay, Antarctica, to investigate the mobility of this element in the environment. {sup 137}Cs has a half-life of 30 years. Because of this, it is environmentally persistent and has been shown to accumulate in marine organisms. The mean reference inventory of this radionuclide in Admiralty Bay sediments, determined using high resolution gamma ray spectrometry, was 20.23 ± 8.94 Bq m{sup −2}, and within the ambient {sup 137}Cs activity range. A model of {sup 137}Cs diffusion–convection was applied to data collected from 1 cm intervals in sediment cores with the aim of providing insights with respect to this element's behavior in sediments. Model results showed a significant correlation between measured and modeled values using the concentrations of {sup 137}Cs, and estimated input into the system from the global fallout of past nuclear tests and expected values based on local sedimentation rates. Results highlight the importance of accounting for the vertical diffusion of {sup 137}Cs in marine sediments when used as a tracer for environmental processes and for assessing potential bioavailability. - Highlights: ► Cesium-137 ({sup 137}Cs) is produced exclusively by anthropogenic processes. ► A model of diffusion–convection simulated {sup 137}Cs environmental behavior. ► This is important for assessing the bioavailability of this toxic element. ► In Antarctica ice cover influenced the input to the sediments.

  11. Effect of sediment size on bioleaching of heavy metals from contaminated sediments of Izmir Inner Bay.

    Science.gov (United States)

    Guven, Duyusen E; Akinci, Gorkem

    2013-09-01

    The effect of sediment size on metals bioleaching from bay sediments was investigated by using fine (bioleaching. Microbial activity was provided with mixed cultures of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans. The bioleaching process was carried out in flask experiments for 48 days, by using 5% (W/V) of solid concentration in suspension. Bioleaching was found to be efficient for the removal of selected heavy metals from every size fraction of sediments, where the experiments with the smaller particles resulted in the highest solubilization ratios. At the end of the experimental period, Cr, Cu, Pb and Zn were solubilized to the ratios of 68%, 88%, 72%, and 91% from the fine sediment, respectively. Higher removal efficiencies can be explained by the larger surface area provided by the smaller particles. The changes in the chemical forms of metals were determined and most of the metal releases were observed from the reducible and organic fractions independent from grain size. Higher concentrations were monitored in the residual fraction after bioleaching period, suggesting they are trapped in this fraction, and cannot be solubilized under natural conditions.

  12. Geochemistry and mineralogy of recent sediments of Guanabara Bay (NE sector) and its major rivers - Rio de Janeiro State - Brazil

    OpenAIRE

    FARIA, MARCIA DE MELO; SANCHEZ, BRAZ A.

    2001-01-01

    Geochemical and clay mineralogical studies of bottom sediments collected along the Macacu and Caceribu rivers and Guanabara Bay were carried out in order to investigate the relationship between major source areas and recent sediments of the bay. Clay mineralogy includes different groups with selective distribution conditioned by geomorphic features and depositional settings. Micaceous clay minerals are abundant near parent rock in the upper course, whereas kaolinite derived from varied source...

  13. Temporal variation of persistent organic pollutant (POP) residue concentrations in sediments from the bay of Chetumal, Mexico.

    Science.gov (United States)

    Noreña-Barroso, E; Gold-Bouchot, G; Ceja-Moreno, V

    2007-08-01

    Bay of Chetumal is a transboundary priority area for the Mesoamerican Barrier Reef Systems project, which has been studied because it is the receiving body of pollutants from a large agricultural area and the city of Chetumal. Levels of persistent organic pollutants in sediments from the Bay were assessed a few years after a mass mortality event of Mayan catfish (Ariopsis assimilis) occurred in 1996. Recent sediments were collected in the rainy season (1999) and dry season (2000); results show concentrations in general lower than those reported after the fish kill, and a change of chemical profiles in chemical pollution.

  14. Application of 137Cs and 210Pb radionuclides to determine sedimentation rates of recent sediments from Admiralty Bay, Antarctica Peninsula

    International Nuclear Information System (INIS)

    Nascimento, Mylene Giseli do; Martins, Cesar de Castro; Figueira, Rubens C.L.; Montone, Rosalinda C.; Mahiques, Michel M. de; Tessler, Moyses G.

    2009-01-01

    Studies about natural and artificial radionuclides in areas such as the Antarctic are key to understand natural and dynamic processes in marine environments. These studies are important to determine levels of radioactive elements and local sedimentation rates. Five marine sediment cores were collected in different points of Admiralty Bay, in the Antarctic Peninsula. The purpose of this study was to determine 137 Cs, 226 Ra and 210 Pb and sedimentation rates at each site. 137 Cs, 210 Pb and 226 Ra were assayed by gamma-counting through direct measurement of the peak at 661 keV, 47 keV and 609 keV, respectively. Sedimentation rates were obtained by 137 Cs and 210 Pb (CIC and CRS). The activities for 137 Cs ranged from 0.84 to 7.09 Bq kg -1 ; to 226 Ra from 6.77 to 31.07 Bq kg -1 for 210 Pb ranged from 1.10 to 36.90 Bq kg -1 . The sedimentation rates obtained by the three models ranged from 0.11±0.01 cm y -1 to 0.46±0.05 cm y -1 . The levels of 137 Cs registered in this study, as well as in other studies in the Antarctic region indicate that global fallout is the main cause of artificial radionuclides present in this environment, since the Antarctic has not suffered a direct action of human activities that released radioactive elements. The possible grain size variations that occur in the studied points of Admiralty Bay may explain the differences found in the vertical distribution of radionuclides, because of the different values of sedimentation rates and respective dating determined in their profiles. (author)

  15. A sediment budget for the southern reach in San Francisco Bay, CA: Implications for habitat restoration

    Science.gov (United States)

    Shellenbarger, Gregory; Wright, Scott A.; Schoellhamer, David H.

    2013-01-01

    The South Bay Salt Pond Restoration Project is overseeing the restoration of about 6000 ha of former commercial salt-evaporation ponds to tidal marsh and managed wetlands in the southern reach of San Francisco Bay (SFB). As a result of regional groundwater overdrafts prior to the 1970s, parts of the project area have subsided below sea-level and will require between 29 and 45 million m3 of sediment to raise the surface of the subsided areas to elevations appropriate for tidal marsh colonization and development. Therefore, a sufficient sediment supply to the far south SFB subembayment is a critical variable for achieving restoration goals. Although both major tributaries to far south SFB have been seasonally gaged for sediment since 2004, the sediment flux at the Dumbarton Narrows, the bayward boundary of far south SFB, has not been quantified until recently. Using daily suspended-sediment flux data from the gages on Guadalupe River and Coyote Creek, combined with continuous suspended-sediment flux data at Dumbarton Narrows, we computed a sediment budget for far south SFB during Water Years 2009–2011. A Monte Carlo approach was used to quantify the uncertainty of the flux estimates. The sediment flux past Dumbarton Narrows from the north dominates the input to the subembayment. However, environmental conditions in the spring can dramatically influence the direction of springtime flux, which appears to be a dominant influence on the net annual flux. It is estimated that up to several millennia may be required for natural tributary sediments to fill the accommodation space of the subsided former salt ponds, whereas supply from the rest of the bay could fill the space in several centuries. Uncertainty in the measurement of sediment flux is large, in part because small suspended-sediment concentration differences between flood and ebb tides can lead to large differences in total mass exchange. Using Monte Carlo simulations to estimate the random error associated with

  16. A History of Vegetation, Sediment and Nutrient Dynamics at Tivoli North Bay, Hudson Estuary, New York

    Science.gov (United States)

    Sritrairat, Sanpisa; Peteet, Dorothy M.; Kenna, Timothy C.; Sambrotto, Ray; Kurdyla, Dorothy; Guilderson, Tom

    2012-01-01

    We conduct a stratigraphic paleoecological investigation at a Hudson River National Estuarine Research Reserve (HRNERR) site, Tivoli Bays, spanning the past 1100 years. Marsh sediment cores were analyzed for ecosystem changes using multiple proxies, including pollen, spores, macrofossils, charcoal, sediment bulk chemistry, and stable carbon and nitrogen isotopes. The results reveal climatic shifts such as the warm and dry Medieval Warm Period (MWP) followed by the cooler Little Ice Age (LIA), along with significant anthropogenic influence on the watershed ecosystem. A five-fold expansion of invasive species, including Typha angustifolia and Phragmites australis, is documented along with marked changes in sediment composition and nutrient input. During the last century, a ten-fold sedimentation rate increase due to land-use changes is observed. The large magnitude of shifts in vegetation, sedimentation, and nutrients during the last few centuries suggest that human activities have made the greatest impact to the marshes of the Hudson Estuary during the last millennium. Climate variability and ecosystem changes similar to those observed at other marshes in northeastern and mid-Atlantic estuaries, attest to the widespread regional signature recorded at Tivoli Bays.

  17. Radioanalytical assessment of sedimentation rates in Guajara Bay (Amazon Estuary, N Brazil). A study with unsupported 210Pb and 137Cs modeling

    International Nuclear Information System (INIS)

    Patricia Andrade Neves; Paulo Alves de Lima Ferreira; Marcia Caruso Bicego; Rubens Cesar Lopes Figueira

    2014-01-01

    Guajara Bay is an integral part of the Amazon Estuary system, and functions as the main receiver of urban and industrial wastes from the city of Belem, capital city of PA State (N Brazil). There is a lack of knowledge regarding quantitative measures of sedimentation, such as sedimentation rates, in the literature for this area of the Amazon Estuary. This study aimed the evaluation of recent (time range of 100 years) sedimentation rates in three sediment profiles collected in the coastal system of Guajara Bay with a radioanalytical approach of unsupported 210 Pb and 137 Cs modeling. The mean sedimentation rates for the cores obtained were 0.85 ± 0.12 cm year -1 for Anadim core, 1.02 ± 0.17 cm year -1 for Outeiro core and 0.53 ± 0.04 cm year -1 for Tucunduba core. With the use of three models of sedimentation rate models, it was observed that Anadim and Outeiro core presented constant sedimentation rates for the evaluated time range, but Tucunduba did not. This difference in sedimentation rates was probably due to their different sampling locations that present diverse hydrodynamic regime, with deposition of fine sediments in the upper area of the bay and stronger fluvial currents in the southernmost region. (author)

  18. Superficial distribution of aromatic compounds and geomicrobiology of sediments from Suruí Mangrove, Guanabara Bay, RJ, Brazil.

    Science.gov (United States)

    Fontana, Luiz F; da Silva, Frederico S; de Figueiredo, Natália G; Brum, Daniel M; Netto, Annibal D Pereira; de Gigueiredo Junior, Alberto G; Crapez, Mirian A C

    2010-12-01

    The distribution of selected aromatic compounds and microbiology were assessed in superficial sediments from Suruí Mangrove, Guanabara Bay. Samples were collected at 23 stations, and particle size, organic matter, aromatic compounds, microbiology activity, biopolymers, and topography were determined. The concentration of aromatic compounds was distributed in patches over the entire mangrove, and their highest total concentration was determinated in the mangrove's central area. Particle size differed from most mangroves in that Suruí Mangrove has chernies on the edges and in front of the mangrove, and sand across the whole surface, which hampers the relationship between particle size and hydrocarbons. An average @ 10% p/p of organic matter was obtained, and biopolymers presented high concentrations, especially in the central and back areas of the mangrove. The biopolymers were distributed in high concentrations. The presence of fine sediments is an important factor in hydrocarbon accumulation. With high concentration of organic matter and biopolymers, and the topography with chernies and roots protecting the mangrove, calmer areas are created with the deposition of material transported by wave action. Compared to global distributions, concentrations of aromatic compounds in Suruí Mangrove may be classified from moderate to high, showing that the studied area is highly impacted.

  19. Humic Substances from Manila Bay and Bolinao Bay Sediments

    Directory of Open Access Journals (Sweden)

    Elma Llaguno

    1997-12-01

    Full Text Available The C,H,N composition of sedimentary humic acids (HA extracted from three sites in Manila Bay and six sites in Bolinao Bay yielded H/C atomic ratios of 1.1-1.4 and N/C atomic ratios of 0.09 - 0.16. The Manila Bay HA's had lower H/C and N/C ratios compared to those from Bolinao Bay. The IR spectra showed prominent aliphatic C-H and amide I and II bands. Manila Bay HA's also had less diverse molecular composition based on the GC-MS analysis of the CuO and alkaline permanganate oxidation products of the humic acids.

  20. Heavy mineral analysis for assessing the provenance of sandy sediment in the San Francisco Bay Coastal System

    Science.gov (United States)

    Wong, Florence L.; Woodrow, Donald L.; McGann, Mary

    2013-01-01

    Heavy or high-specific gravity minerals make up a small but diagnostic component of sediment that is well suited for determining the provenance and distribution of sediment transported through estuarine and coastal systems worldwide. By this means, we see that surficial sand-sized sediment in the San Francisco Bay Coastal System comes primarily from the Sierra Nevada and associated terranes by way of the Sacramento and San Joaquin Rivers and is transported with little dilution through the San Francisco Bay and out the Golden Gate. Heavy minerals document a slight change from the strictly Sierran-Sacramento mineralogy at the confluence of the two rivers to a composition that includes minor amounts of chert and other Franciscan Complex components west of Carquinez Strait. Between Carquinez Strait and the San Francisco Bar, Sierran sediment is intermingled with Franciscan-modified Sierran sediment. The latter continues out the Gate and turns southward towards beaches of the San Francisco Peninsula. The Sierran sediment also fans out from the San Francisco Bar to merge with a Sierran province on the shelf in the Gulf of the Farallones. Beach-sand sized sediment from the Russian River is transported southward to Point Reyes where it spreads out to define a Franciscan sediment province on the shelf, but does not continue southward to contribute to the sediment in the Golden Gate area.

  1. Use of geochemical biomarkers in bottom sediment to track oil from a spill, San Francisco Bay, California

    Science.gov (United States)

    Hostettler, F.D.; Rapp, J.B.; Kvenvolden, K.A.

    1992-01-01

    In April 1988, approximately 1500 m3 of a San Joaquin Valley crude oil were accidentally released from a Shell Oil Co. refinery near Martinez, Californa. The oil flowed into Carquinez Strait and Suisun Bay in northern San Francisco Bay Sediment and oil samples were collected within a week and analysed for geochemical marker compounds in order to track the molecular signature of the oil spill in the bottom sediment. Identification of the spilled oil in the sediment was complicated by the degraded nature of the oil and the similarity of the remaining, chromatographically resolvable constituents to those already present in the sediments from anthropogenic petroleum contamination, pyrogenic sources, and urban drainage. Ratios of hopane and sterane biomarkers, and of polycyclic aromatic hydrocarbons and their alkylated derivatives best identified the oil impingement. They showed the oil impact at this early stage to be surficial only, and to be patchy even within an area of heavy oil exposure.

  2. Bacteriological study of the superficial sediments of Guanabara bay, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    Frederico Sobrinho da Silva

    2008-03-01

    Full Text Available Thirty sediment samples were collected in Guanabara Bay in August, November and December 2005. The material was analyzed for organic matter, total and faecal coliforms, heterotrophic bacteria, bacterial respiratory activity, esterase activity and electron transport system activity. The organic matter in the superficial sediments (2 cm ranged from 4 to 6%. The highest level of total coliforms and faecal coliforms were 1.7 x 10(5 MPN/g and 1.1 x 10³ MPN/g, respectively. Heterotrophic bacteria presented the highest values at station 7 (4.1 x 10(6 CFU/g and the lowest values at station 3 (7 x 10(4 CFU/g (northwestern part of Guanabara Bay. Esterase enzyme activity showed activity in the sediment of all 30 stations. Electron transport system activity ranged between 0.047 muL O2/h/g and 0.366 muL O2/h/g at six stations. The benthic microbial foodweb is anaerobic. Anaerobic processes such as fermentation, denitrification and sulphate-reduction are responsible for the biogeochemical cycles in the sediment of Guanabara Bay. The input of untreated sewage in the Mangue Channel outflow in Guanabara Bay has favored the increase of the organic load, and the maintenance of the total coliforms and faecal coliforms in the sediment. Faecal coliforms have been reported to be a good indicator of aquatic pollution and organic contamination in the water column, but total coliforms may be an ideal candidate group for sediment quality tests as well.Trinta amostras de sedimento foram coletadas na Baía de Guanabara em agosto, novembro e dezembro de 2005. Foram analisados matéria orgânica, coliformes totais e fecais, bactéria heterotrófica, atividade respiratória bacteriana, atividade de esterase e do sistema transportador de elétrons. A matéria orgânica no sedimento superficial variou entre 4 e 6%. O maior nível de coliformes totais e fecais foi 1.7 x 10(5 MPN/g e 1.1 x 10³ MPN/g, respectivamente. Bactérias heterótrofas mostraram o maior valor na esta

  3. Geochemical analysis of sediments from a semi-enclosed bay (Dongshan Bay, southeast China) to determine the anthropogenic impact and source.

    Science.gov (United States)

    Xu, Yonghang; Sun, Qinqin; Ye, Xiang; Yin, Xijie; Li, Dongyi; Wang, Liang; Wang, Aijun; Li, Yunhai

    2017-05-01

    The geochemical compositions of sediments in the Dongshan Bay, a semi-enclosed bay on the southeast coast of China, were obtained to identify pollutant sources and evaluate the anthropogenic impacts over the last 100 years. The results indicated that the metal flux had been increasing since the 1980s. Enrichment factor values (Pb, Zn and Cu) suggested only slight enrichment. The proportion of anthropogenic Pb changed from 9% to 15% during 2000-2014. Coal combustion might be an important contamination source in the Dongshan Bay. The historical variation in the metal flux reflected the economic development and urbanization in the Zhangjiang drainage area in the past 30 years. According to the Landsat satellite remote sensing data, the urbanization area expanded approximately three times from 1995 to 2010. The δ 13 C values (-21‰ to -23‰) of the organic matter (OM) in the sediments indicated that the OM was primarily sourced from aquatic, terrigenous and marsh C 3 plants. Nitrogen was mainly derived from aquatic plants and terrigenous erosion before the 1980s. However, the total organic carbon (TOC) contents, total nitrogen (TN) contents and δ 15 N had been increasing since the 1980s, which suggested that the sources of nitrogen were soil erosion, fertilizer and sewage. In addition, the TOC and TN fluxes in the Dongshan Bay had significantly increased since the 1980s, which reflected the use of N fertilizer. However, the TOC and TN fluxes significantly decreased in the past decade because environmental awareness increased and environmental protection policies were implemented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Anthropogenic influences on shoreline and nearshore evolution in the San Francisco Bay coastal system

    Science.gov (United States)

    Dallas, K.L.; Barnard, P.L.

    2011-01-01

    Analysis of four historical bathymetric surveys over a 132-year period has revealed significant changes to the morphology of the San Francisco Bar, an ebb-tidal delta at the mouth of San Francisco Bay estuary. From 1873 to 2005 the San Francisco Bar vertically-eroded an average of 80 cm over a 125 km2 area, which equates to a total volume loss of 100 ± 52 million m3 of fine- to coarse-grained sand. Comparison of the surveys indicates the entire ebb-tidal delta contracted radially, with the crest moving landward an average of 1 km. Long-term erosion of the ebb-tidal delta is hypothesized to be due to a reduction in the tidal prism of San Francisco Bay and a decrease in coastal sediment supply, both as a result of anthropogenic activities. Prior research indicates that the tidal prism of the estuary was reduced by 9% from filling, diking, and sedimentation. Compilation of historical records dating back to 1900 reveals that a minimum of 200 million m3 of sediment has been permanently removed from the San Francisco Bay coastal system through dredging, aggregate mining, and borrow pit mining. Of this total, ~54 million m3 of sand-sized or coarser sediment was removed from central San Francisco Bay. With grain sizes comparable to the ebb-tidal delta, and its direct connection to the bay mouth, removal of sediments from central San Francisco Bay may limit the sand supply to the delta and open coast beaches. SWAN wave modeling illustrates that changes to the morphology of the San Francisco Bar have altered the alongshore wave energy distribution at adjacent Ocean Beach, and thus may be a significant factor in a persistent beach erosion ‘hot spot’ occurring in the area. Shoreline change analyses show that the sandy shoreline in the shadow of the ebb-tidal delta experienced long-term (1850s/1890s to 2002) and short-term (1960s/1980s to 2002) accretion while the adjacent sandy shoreline exposed to open-ocean waves experienced long-term and short-term erosion. Therefore

  5. Over 100 years of environmental change recorded by foraminifers and sediments in Mobile Bay, Alabama, Gulf of Mexico, USA

    Science.gov (United States)

    Osterman, Lisa E.; Smith, Christopher G.

    2012-12-01

    The marine microfauna of Mobile Bay has been profoundly influenced by the development and expansion of the primary shipping channel over the last ˜100 years. Foraminifers and sediments from seven box cores with excess lead-210 chronology document that channel dredging and spoil disposal have altered circulation, reduced estuarine mixing, changed sedimentation patterns, and caused a faunal turnover within the bay. Beginning in the late 1800s, changes in estuarine mixing allowed for greater low-pH freshwater influence in the bay, and ultimately began environmental changes that resulted in the loss of calcareous foraminifers. By the early 1900s, box cores throughout Mobile Bay record a ˜100-year trend of increasing calcareous test dissolution that continues to the present. Since the completion of the current shipping channel in the 1950s, restricted tidal flushing and increased terrestrial organic matter, documented by carbon-to-nitrogen ratios, stimulated an increase in agglutinated foraminiferal densities. However, in deeper areas of the bay, hypoxic water has negatively impacted the marine microfauna. Comparisons of the present-day foraminiferal assemblage with foraminifers collected in the early 1970s indicate that the continued biologic loss of calcareous foraminifers in the bay has allowed the introduction of a new agglutinated foraminiferal species into the bay.

  6. Extraction procedure compared to attenuation model to assess heavy metals mobility in sediments from Sepetiba Bay, Rio de Janeiro

    International Nuclear Information System (INIS)

    Ribeiro, Andreza Portella

    2006-01-01

    Sepetiba bay, located about 60 km west of the metropolitan region of Rio de Janeiro city, has undergone notable development in the last decades, with the establishment of about 400 industrial plants in its basin, basically metallurgical, which release its industrial waste either straight into the bay or through local rivers. The Sepetiba harbor also brought up a lot of industrial investment in that area. This urban and industrial expansion caused several environmental impacts, mainly due to the presence of heavy metals and other potentially toxic substances present in the effluents discharged into the bay. This work aimed to assess heavy metal (Cd, Cu, Ni, Pb e Zn) contamination and mobility in sediments from Sepetiba bay. The acid-volatile sulfides (AVS) and the concentration of simultaneously extracted metals (SIGMA[SEM) were determined in 65 sediment samples from Sepetiba bay, representing the whole area. The results obtained showed that Cd, Cu, Pb and Zn presented higher concentrations in the northeastern area (mainly in the mouth of Guandu and Canal de Sao Francisco rivers), while the highest concentration of Ni were observed in the western region of the bay. The comparison between SEM concentrations with the Canadian Sediment Quality Guidelines (TEL and PEL) indicated that Cd and Zn presented values which may hazard to aquatic organisms (concentration levels above PEL); the elements Cu, Pb and Ni presented concentration levels below PEL, suggesting low probability of toxicological effects to the aquatic organisms. On the other hand, the ratio Σ[SEM]/[AVS] was below 1 in the northeastern region, indicating that, in spite of the high concentration of the analyzed metals in this area, they are trapped in the sediment, as sulfides. The total metal concentrations in the sediments were also determined and the same distribution pattern obtained for the SEM were observed, with high concentrations in the northeastern region of the bay, classifying the area as level 2

  7. Stormwater impact in Guanabara Bay (Rio de Janeiro): Evidences of seasonal variability in the dynamic of the sediment heavy metals

    Science.gov (United States)

    Fonseca, E. M.; Baptista Neto, J. A.; Silva, C. G.; McAlister, J. J.; Smith, B. J.; Fernandez, M. A.

    2013-09-01

    Guanabara Bay is one of the most prominent coastal bays in Brazil. This environment is an estuary of 91 rivers and channels, surrounded by the metropolis of Rio de Janeiro. The bay receives considerable amounts of contaminants introduced from sewage effluents, industrial discharge, urban and agricultural runoff, atmospheric fallout, and the combined inputs from the rivers, making Guanabara Bay one of the most polluted coastal environments on the Brazilian coastline. The aim of this work is to study the concentration and fractionation of the heavy metals within the sediments of the bay. In order to understand the possible seasonal influence on the heavy metal fractionation, two campaigns were carried out in two different seasons of the year (rainy and dry). Twelve stations, in four different areas, with different oceanographic characteristics, where chosen. To assess the bioavailability of the metals a selective extraction procedure was used to study the geochemical fractionation and bioavailability of Zn, Cu, Cr, Ni and Pb. The rainy season was very important with respect to variation in the total concentrations of Cr, Ni and Pb and their fractionation within different "operational" phases present in Guanabara Bay sediments. The water-soluble phase showed little importance, with respect to metal adsorption and this would suggest very low mobility of metals in the water column. Nevertheless, the potentially available metals within these sediments showed a high probability for their release and therefore cause contamination of the water column, since different parts of the bay are constantly subjected to dredging projects promoted by the harbor authorities.

  8. What Role do Nor'Easters have on the Jamaica Bay Wetlands Sediment Budget?

    Science.gov (United States)

    Clarke, R. C.; Bentley, S. J.; Wang, H.; Smith, J.

    2017-12-01

    The wetlands of Jamaica Bay, located on the outskirts of Queens, New York, have lost over half their surface area in the last 50 years due both anthropogenic and natural causes, including channel dredging, urban drainage construction, and greater tidal amplitudes partially due to rising local sea levels. Superstorm Sandy made landfall in 2014 as a powerful coastal geomorphic agent, highlighting the vulnerability of that region to large cyclonic storms that are more commonly encountered along coastal reaches of southeastern North America. After this event, research aimed at quantifying the geomorphic impact of Superstorm Sandy and to evaluate the record of past documented major winter storms on Jamaica Bay's wetlands. 12 sediment cores were collected from the surface of remaining wetlands in August 2014 by the USGS Wetland and Aquatic Research Center; the cores have been analyzed for Pb-210/Cs-137 geochronology, organic content, and water content to establish chronology of mineral sediment supply to the wetlands over the past 120 years. Most cores were found to be organic-rich, marked with periodic cm-scale beds with increased mineral content. Historic storm data, dating as far back as the late 1800's, were used to identify hurricanes and major winter storms determined by the National Weather Service passing within 100 km of the study area. Likely storm-event deposits in each core were identified as layers with mineral content higher than the core mean plus one standard deviation, and were matched to historic events via radioisotope geochronology, incorporating age-model uncertainty. Overall, 22 out of the 35 defined storm layers match the timing of historic strong storms (within uncertainty ranging from 2 to 5 years) from 1894 to Superstorm Sandy in 2014. Our findings show that over multidecadal timescales, nor'easters and winter storms play a role in the vertical accretion of sediment in the Jamaica Bay wetlands, but are substantially less important than sediment

  9. Hydrogen and acetate cycling in two sulfate-reducing sediments: Buzzards Bay and Town Cove, Massachusetts

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, P.C. (SUNY, Stony Brook, NY (USA) Univ. of Colorado, Boulder (USA)); Michelson, A.R.; Scranton, M.I. (SUNY, Stony Brook, NY (USA)); Banta, G.T.; Hobbie, J.E. (Marine Biological Laboratory, Woods, Hole, MA (USA)); Howarth, R.W. (Cornell Univ., Ithaca, NY (USA))

    1988-10-01

    Molecular hydrogen and acetate are believed to be key intermediates in the anaerobic remineralization of organic carbon. The authors have made measurements of the cycling of both these compounds in two marine sediments: the bioturbated sediments of Buzzards Bay, Mass., and the much more reducing sediments of Town Cove, Orleans, Mass. Hydrogen concentrations are similar in these environments (from less than 5 to 30 nM), and are within the range previously reported for coastal sediments. However, apparent hydrogen production rates differ by a factor of 60 between these two sediments and at both sites show strong correlation with measured rates of sulfate reduction. Acetate concentrations generally increased with depth in both environments; this increase was greater in Buzzards Bay (22.5 to 71.5 {mu}M) than in Town Cove (26 to 44 {mu}M). Acetate oxidation rates calculated from measured concentrations and {sup 14}C-acetate consumption rate constants suggest that the measured acetate was not all available to sulfate-reducing bacteria. Using the measured sulfate reduction rates, they estimate that between 2% and 100% of the measured acetate pool is biologically available, and that the bioavailable pool decreases with depth. A diagenetic model of the total acetate concentration suggests that consumption may be first order with respect to only a fraction of the total pool.

  10. Distribution of radionuclides in a marine sediment core off the waterspout of the nuclear power plants in Daya Bay, northeastern South China Sea

    International Nuclear Information System (INIS)

    Zhou, Peng; Li, Dongmei; Li, Haitao; Fang, Hongda; Huang, Chuguang; Zhang, Yusheng; Zhang, Hongbiao; Zhao, Li; Zhou, Junjie; Wang, Hua; Yang, Jie

    2015-01-01

    A sediment core was collected and dated using 210 Pb ex dating method off the waterspout of nuclear power base of Daya Bay, northeastern South China Sea. The γ-emitting radionuclides were analyzed using HPGe γ spectrometry, gross alpha and beta radioactivity as well as other geochemical indicators were deliberated to assess the impact of nuclear power plants (NPP) operation and to study the past environment changes. It suggested that NPP provided no new radioactivity source to sediment based on the low specific activity of 137 Cs. Two broad peaks of TOC, TC and LOI accorded well with the commercial operations of Daya Bay NPP (1994.2 and 1994.5) and LNPP Phase I (2002.5 and 2003.3), implying that the mass input of cooling water from NPP may result into a substantial change in the ecological environment and Daya Bay has been severely impacted by human activities. - Graphical abstract: A sediment core was collected and dated using 210 Pb ex dating method, off the waterspout of nuclear power base of Daya Bay, northeastern South China Sea. The γ-emitting radionuclides analyzed using the HPGe γ spectrometry, gross alpha and beta radioactivity as well as other geochemical indicators were deliberated to study the past environment changes and assess the impact of nuclear power plants (NPP) operation. NPP provided no new radioactivity source to sediment, but the mass input of cooling water from nuclear power plants may result into a substantial change in the ecological environment and Daya Bay has been severely impacted by human activities. - Highlights: • A sediment core collected from Daya Bay, South China Sea was dated using 210 Pb ex method. • The γ-emitting radionuclides, gross α and β, TOC, TIC, TC, LOI were deliberated to assess the impact of nuclear power plants (NPP) operation. • The low activity of 137 Cs in sediment suggested NPP provided no new radioactivity source. • Two peaks of TOC, TC and LOI implied that the mass input of NPP cooling water may

  11. Seagrass vegetation and meiofauna enhance the bacterial abundance in the Baltic Sea sediments (Puck Bay)

    OpenAIRE

    Jankowska, Emilia; Jankowska, Katarzyna; Włodarska-Kowalczuk, Maria

    2015-01-01

    This study presents the first report on bacterial communities in the sediments of eelgrass (Zostera marina) meadows in the shallow southern Baltic Sea (Puck Bay). Total bacterial cell numbers (TBNs) and bacteria biomass (BBM) assessed with the use of epifluorescence microscope and Norland’s formula were compared between bare and vegetated sediments at two localities and in two sampling summer months. Significantly higher TBNs and BBM (PERMANOVA tests, P 

  12. Effects of Sediment Characteristics on the Accumulation and Transfer Rate of Heavy Metals in Mangrove Trees (Case Study: Nayband Bay and Qeshm Island

    Directory of Open Access Journals (Sweden)

    H. Moradi

    2014-09-01

    Full Text Available In this paper, the accumulation of heavy metals of Nickel (Ni and Vanadium (V was measured in habitat sediments, mangrove roots and leaves (Avicennia marina. Besides, the transfer of Ni and V from the sediment to root and to the leaves in Nayband Bay and Qeshm Island were studied. The samples were gathered by Systematic-random Sampling using selective transects at 16 stations at the end of mangrove cover in both sides of land and sea in two habitats with three replicates of sediment, root and leave samples. The bed characteristics including sediment texture, pH, EC and organic matters were determined. The concentration of Ni and V was measured by atomic absorption spectroscopy (AAS, and then the metal transfer factor from sediment to root and root to leave was calculated. The correlation of the metal transfer factor and sediment characteristics was analyzed using the SPSS software (version 19. In the sample of sediments, roots and leaves respectively, the most concentrations of nickel and vanadium were measured. About transfer of Ni and V, transfer rate from sediment to root was much higher than from root to leave. In addition, the highest transfer factor from sediment to root and from root to leave was obtained for V in Qeshm habitat (0.502 and for Ni (0.749 in Nayband Bay. It seems that the difference between sediment textures in the two habitats and widespread oil and gas activities in Nayband Bay might be the notable reasons for the difference in transfer rates in two the habitats. Therefore, we conclude that the finer texture of Qeshm habitat increased transfer of V from sediment to root, and the coarser texture associated with increasing air pollution in Nayband Bay caused more Ni to accumulate in the leaves.

  13. Reconstruction of metal pollution and recent sedimentation processes in Havana Bay (Cuba): A tool for coastal ecosystem management

    International Nuclear Information System (INIS)

    Díaz-Asencio, M.; Alvarado, J.A. Corcho; Alonso-Hernández, C.; Quejido-Cabezas, A.; Ruiz-Fernández, A.C.; Sanchez-Sanchez, M.; Gómez-Mancebo, M.B.; Froidevaux, P.; Sanchez-Cabeza, J.A.

    2011-01-01

    Highlights: ► Past metal pollution in the heavy polluted coastal ecosystem of Havana Bay. ► Effectiveness of pollution-reduction strategies. ► Dated environmental archives to reconstruct sedimentation and pollution trends. ► Impact of severe climatic events on sedimentation. - Abstract: Since 1998 the highly polluted Havana Bay ecosystem has been the subject of a mitigation program. In order to determine whether pollution-reduction strategies were effective, we have evaluated the historical trends of pollution recorded in sediments of the Bay. A sediment core was dated radiometrically using natural and artificial fallout radionuclides. An irregularity in the 210 Pb record was caused by an episode of accelerated sedimentation. This episode was dated to occur in 1982, a year coincident with the heaviest rains reported in Havana over the XX century. Peaks of mass accumulation rates (MAR) were associated with hurricanes and intensive rains. In the past 60 years, these maxima are related to strong El Niño periods, which are known to increase rainfall in the north Caribbean region. We observed a steady increase of pollution (mainly Pb, Zn, Sn, and Hg) since the beginning of the century to the mid 90s, with enrichment factors as high as 6. MAR and pollution decreased rapidly after the mid 90s, although some trace metal levels remain high. This reduction was due to the integrated coastal zone management program introduced in the late 90s, which dismissed catchment erosion and pollution.

  14. Study on sediments from Almirantado Bay in the Antarctica continent

    International Nuclear Information System (INIS)

    Gomes, Marcelo da Silva; Montone, Rosalinda Carmela; Weber, Rolf Roland

    1999-01-01

    The Antarctic Continent is relatively free from human activities but it already comes presenting low levels of environmental contamination for anthropogenic sources. The anthropogenic contamination can be taken mainly to the continent through different manners for the marine and atmospheric currents. This work has as objective to analyze samples of sediments from Antarctic Continent in the area of Almirantado Bay, where the Brazilian Station of Resource Comandante Ferraz is located. The concentrations of ten metallic elements (Ni, Cu, Zn, Cd, Sn, Pb, U, Al, Fe and Li) were analyzed in twelve collection sites along the whole Bay. AAS and HR-ICPMS accomplished the analyses of those metallic elements. It was verified in the obtained results that a variation does not exist in the concentrations obtained among the collection sites, indicating a homogeneity in the area and there is no evidence of polluting source, at least at those obtained concentration levels. (author)

  15. Evaluation of Soil Erosion and Sediment Yield from Ridge Watersheds Leading to Guánica Bay, Puerto Rico, Using SWAT Model

    Science.gov (United States)

    Increased sediment loading to reservoirs and, ultimately, to Guánica Bay and reef areas is a significant concern in Puerto Rico. Sediment deposition has significantly reduced storage capacity of reservoirs, and sediment-attached contaminants can stress corals and negative...

  16. Radium isotopes in Port Phillip Bay: estimation of the rate of bio irrigation of sediments, and water residence time

    International Nuclear Information System (INIS)

    Hancock, G.J.; Webster, I.T.

    1998-01-01

    Recent work has shown that estuarine sediments are a source of radium (Ra) to coastal waters (Bollinger and Moore, 1982, Webster et al., 1994; Hancock et al., 1997). Ra is soluble in saline water (Moore, 1992, Webster et al., 1995) and is rapidly desorbed into porewater from deposited fluvial sediments where it is continuously generated by insoluble Th parents. The rate at which Ra effuses into surface water has been used to determine the rate of surface-water pore water exchange (Hancock and Murray, 1996). Once in the water column, the behaviour of Ra is essentially conservative, enabling the determination of water residence time in a semi-enclosed estuary (Turekian et al., 1996). Here we use measurements of Ra in an estuary to estimate two water mixing processes. Port Phillip Bay (PPB) is a semi-enclosed estuary adjacent to the city of Melbourne, one of the highest density population centres in Australia. The Bay is approximately 50 km in diameter, and has an average depth of 14 m. A recent study found that the potential for eutrophication and algal blooms in the Bay was intricately linked to the fate of nutrients, particularly nitrogen, discharged into the Bay from rivers, drains, and sewage treatment plants (Harris et al. 1996). Two of the most important processes controlling the levels of inorganic N in the water column were identified as bio irrigation of bottom sediments, and the rate of exchange of Bay water with ocean water via Bass Strait. In this paper we describe how Ra isotopes can be used to estimate the rates of these processes, and we compare these rates with estimates made using conventional techniques. Water and sediment samples were collected from five sites in February 1996. Sediment cores were collected by divers, frozen, and sectioned in the laboratory. Surface, mid depth and bottom water samples were collected using a Niskin bottle. Radionuclide activities were determined by alpha spectrometry (Martin and Hancock, 1992) and gamma spectrometry

  17. Contrasting sedimentation patterns in two semi-enclosed mesotidal bays along the west and south coasts of Korea controlled by their orientation to the regional monsoon climate

    Science.gov (United States)

    Hong, Seok Hwi; Chun, Seung Soo; Chang, Tae Soo; Jang, Dae Geon

    2017-08-01

    Sedimentation patterns of tidal flats along the Korean west coast have long been known to be largely controlled by the monsoon climate. On the other hand, much less is known about the effect of the monsoon on sedimentation in coastal embayments with mouths of different geographic orientations. Good examples are Hampyeong and Yeoja bays along the west and south coasts, respectively. Both have narrow entrances, but their mouths open toward the northwest and the south, respectively. With mean tidal ranges of 3.46 and 3.2 m, respectively, the two bays experience similar tidal regimes and are hence excellent candidates to compare the effect of different exposure to the same regional monsoon climate on their respective sediment distribution patterns. The winter monsoon, in particular, is characterized by strong northwesterly winds that directly impact the west coast, but blow offshore along the south coast. For the purpose of this study, surficial sediment samples were collected from intertidal and subtidal flats of the two bays, both in summer and winter. Grain-size analyses were carried out by sieving (sand fraction) and Sedigraph (mud fraction). In the case of Yeoja Bay, the sediments consist mostly of mud (mean grain sizes of 5.4 to 8.8 phi). Seasonal changes are very subtle, the sediments being slightly coarser in summer when silt-dominated sediments are supplied by two streams to the northern parts of the bay in response to heavy rainfall. With the exception of the deeper tidal channels, Yeoja Bay is characterized by a thick mud blanket the year round, which is modulated by processes associated with the summer monsoon that predominantly blows from the east. Textural parameters suggest severely restricted sediment mixing on the subtidal and intertidal flats, the overall low energy situation preventing sands from reaching the tidal flats. The sediments of Hampyeong Bay, by contrast, are characterized by a distinct shoreward fining trend. Mean grain sizes average

  18. Observation of sediment resuspension in Old Tampa Bay, Florida

    Science.gov (United States)

    Schoellhamer, David H.; ,

    1990-01-01

    Equipment and methodology have been developed to monitor sediment resuspension at two sites in Old Tampa Bay. Velocities are measured with electromagnetic current meters and suspended solids and turbidity are monitored with optical backscatterance sensors. In late November 1989, a vertical array of instrument pairs was deployed from a permanent platform at a deep-water site, and a submersible instrument package with a single pair of instruments was deployed at a shallow-water site. Wind waves caused resuspension at the shallow-water site, but not at the deeper platform site, and spring tidal currents did not cause resuspension at either site.

  19. Strategy of Developing Tomini Bay for Economic Growth of Coastal Community in Central Sulawesi

    Directory of Open Access Journals (Sweden)

    Muzakir Muzakir

    2016-06-01

    Full Text Available This research aims to analyze the potential and the strategy of developing Tomini Bay to improve the economic growth of the coastal community in Central Sulawesi. The research is located in four regencies in Central Sulawesi. The method uses the descriptive analysis using SWOT analysis. The research result shows that the potential of fisheries resources in Poso Regency, Parigi Moutong Regency, Tojo Una-Una Regency, and Banggai Regency can support the development of Tomini Bay region based on fisheries in order to accelerate the economic growth of coastal communities in Central Sulawesi. The potential fishery resources that can support the development of Tomini Bay area are the potential of fisheries, marine and coastal infrastructure, social economy and geographic conditions in four regencies. The strategies are building the marketing network for fishery products both the catching and cultivation, improving the fishery human resouce capacity, controlling the fishery product quality, and increasing the social awareness to maintain the ecosystem sustainability. To optimize the utilization of Tomini Bay, it is suggested to improve the involvement of the regional government, the central government, and also the private sector and the whole community.

  20. PRELIMINARY STUDY OF SEDIMENT AGES AND ACCUMULATION RATES IN JAKARTA BAY DERIVED FROM DEPTH PROFILES OF UNSUPPORTED 210Pb

    Directory of Open Access Journals (Sweden)

    Ali Arman Lubis

    2010-06-01

    Full Text Available Preliminary study of sediment ages and accumulation rates has been carried out in Jakarta Bay using unsupported 210Pb. 210Pb occurs naturally in sediments as one of the radioisotopes in the 238U decay series. The total 210Pb activity in sediments has two components, namely; supported and unsupported. The latter derives from dissociation of 210Pb from 226Ra through diffusion of the intermediate gaseous isotope 222Rn which diffuse into the atmosphere and decay to 210Pb. 210Pb falling directly into seawater and deposit on the bed of the marine with sediments. 210Pb has half-life of 22.26 years makes it well suited to dating and determining the accumulation rate of sediments laid down over the past 100 - 150 years. Two cores samples with diameter 7.5 cm were taken by scuba divers from Jakarta Bay and were analyzed of 210Pb using α-spectrometer equipped with PIPS detector. The sediment ages and range of sediment accumulation rates of core I and II are up to 169 years and (0.25 - 1.93 kg/m2y and up to 157 years and (0.15 - 2.68 kg/m2y, respectively.  Keywords: sediment ages, accumulation rates, marine sediment, 210Pb

  1. The coupling of bay hydrodynamics with sediment supply and micro-tidal wetland stability under high rates of relative sea level rise

    Science.gov (United States)

    Wang, J.; Xu, K.; Restreppo, G. A.; Bentley, S. J.; Meng, X.; Zhang, X.

    2017-12-01

    Due to global sea level rise, local subsidence and sediment deficit, the Mississippi River (MR) deltaic plain has lost a total of 25% of coastal Louisiana's wetlands during the last century, leading to huge losses of ecological services, economic and social crises. Ecosystem-based restoration strategies which rely on coastal system processes and feedbacks are urgently needed. Understanding linkages between estuarine and coastal systems and the adjacent marshlands will help the designing strategies. To investigate bay hydrodynamics and its impacts on the adjacent micro-tidal wetland stability, hourly measurements of wave, tidal current, and benthic sediment concentration in summer, winter, and spring of 2015-2016 were conducted in Fourleague Bay, Louisiana, USA. The bay-marsh system has been stable for almost 80 years under high relative sea level rising rate, which is 11 km southeast of the Atchafalaya River mouth, with a water depth of 1-3 m. High-temporal resolution data indicate that benthic sediment resuspension is mainly caused by wind-driven waves with a dominant periodicity of 4.8 d. The sediment flux reaches 28 g·m-1·s-1 per unit depth in cm during the events. Net sediment transport is northwestward in summer, and southeastward in winter and spring. Sediment flux available for surrounding marsh varies from 0-500 g·m-1·s-1. An optimal inundation depth of 50 cm is estimated by the equilibrium wetland elevation change model under high relative sea level rising rate of 1.57 cm·yr-1. Seasonal variations of river discharge and wind direction (particularly speeds >3 m·s-1) greatly impact potential sediment contribution from bay to the surrounding wetlands. Three sediment transport regimes are concluded based on the seasonal variations of river discharge and wind direction: the `bypassing' season, the resuspension-accumulation season, and the combined `bypassing' and resuspension-accumulation season. The bay hydrodynamic processes and their impacts on the

  2. [Calculation of environmental dredging depth of heavy sediments in Zhushan Bay of Taihu Lake metal polluted].

    Science.gov (United States)

    Jiang, Xia; Wang, Wen-Wen; Wang, Shu-Hang; Jin, Xiang-Can

    2012-04-01

    Horizontal distribution of heavy metals in surface sediments of Zhushan Bay was investigated, and core sediment samples were collected in the representative area. Core sediments were divided into oxide layer (A), polluted layer (B), upper polluted transition layer(C1), lower polluted transition layer(C2) and normal mud layer(D) from top to bottom. The change of total contents of Cr, Ni, Cu, Zn, As, Cd, Hg, Pb and contents of biological available Cr, Ni, Cu, Zn, As, Cd, Pb with depths were analyzed. Ecological risk assessment of heavy metals in sediments was done by potential ecological risk index method. At last, environmental dredging depth was calculated. The results shows that the contents of Cr, Ni, Cu, Zn, As, Cd, Hg, Pb are 30.56-216.58, 24.07-59.95, 16.71-140.30, 84.31-193.43, 3.39-22.30, 0.37-1.59, 0.00-0.80 and 9.67-99.35 mg x kg(-1), respectively. The average concentrations of Cr, Ni, Cu, Zn, As, Cd, Hg, Pb are 79.74, 37.74, 44.83, 122.39, 10.39, 0.77, 0.14 and 40.08 mg x kg(-1), respectively. Heavy metals in the surface sediments of Zhushan Bay mainly distribute in the west bank and the estuaries of Taige canal, Yincun Port, and Huanshan River,and Cd pollution is relatively serious. There is an accumulative effect of heavy metals in Zhushan Bay, and the contents of biological available metals decrease with depths. Ecological risk grades of Cd in layer A and B are high, and the comprehensive potential ecological risk grades of each layer are in middle or low. The environmental dredging layers are A and B, and the average dredging depth is 0.39 m.

  3. Spatial distribution of pollen grains and spores in surface sediments of Guanabara Bay, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Barreto, Cintia F; Vilela, Claudia G; Baptista-Neto, José A; Barth, Ortrud M

    2012-09-01

    Aiming to investigate the deposition of pollen grains and spores in Guanabara Bay, Rio de Janeiro State, 61 surface sediment samples were analyzed. The results showed that the current deposition of palynomorphs in surface sediments of Guanabara Bay represents the regional vegetation of this hydrographic basin. The differential distribution of palynomorphs followed a pattern influenced by bathymetry, tidal currents speed, discharge of numerous rivers, and by human activity. The dominance of representatives of Field Vegetation reflects the changes of the original flora caused by intense human activities in the region. The continued presence and richness of pollen types of rain forest in the samples indicates that their source area might be the vegetation from riparian border of rivers in the western sector of the Bay, where the mangrove vegetation is being preserved. The large amount of damaged palynomorphs may be related to abrasion that occurs during river transport, indicating removal or reworking from their areas of origin.

  4. Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2014–15

    Science.gov (United States)

    Buchanan, Paul A.; Downing-Kunz, Maureen; Schoellhamer, David H.; Livsey, Daniel N.

    2018-03-08

    The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay (bay) as part of a multi-agency effort to address management, water supply, and ecological concerns. The San Francisco Bay area is home to millions of people, and the bay teems both with resident and with migratory wildlife, plants, and fish. Freshwater mixes with salt water in the bay, which is subject both to riverine influences (floods, droughts, managed reservoir releases and freshwater diversions) and to marine influences (tides, waves, effects of salt water). To understand this environment, the USGS, along with its partners (see “Acknowledgements”), has been monitoring the bay’s waters continuously since 1988. Several water-quality variables are of particular importance to State and Federal resource managers and are monitored at key locations throughout the bay (fig. 1). Salinity, which indicates the relative mixing of fresh and ocean waters in the bay, is derived from specific conductance measurements. Water temperature, along with salinity, affects the density of water, which controls gravity-driven circulation patterns and stratification in the water column. Turbidity, a measure of light scattered from suspended particles in the water, is used to estimate suspended-sediment concentration (SSC). Suspended sediment affects the bay in multiple ways: attenuation of sunlight in the water column, affecting phytoplankton growth; deposition on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; deposition in ports and shipping channels, which can necessitate dredging; and often, adsorption of contaminants, affecting their distribution and concentrations in the environment. Dissolved oxygen concentration, essential to a healthy ecosystem and a fundamental indicator of water quality, is affected by water temperature, salinity, ecosystem metabolism, tidal currents, and wind. Tidal currents in the bay

  5. Influence of urbanization and industrialization on metal enrichment of sediment cores from Shantou Bay, South China

    International Nuclear Information System (INIS)

    Qiao, Yongmin; Yang, Yang; Zhao, Jiangang; Tao, Ran; Xu, Ronghua

    2013-01-01

    Four sediment cores were collected to investigate geochemical sources and to assess enrichment and pollution of metals in sediments from Shantou Bay, an area experiencing rapid economic development on the Southeastern Coast of China. The results indicated that the concentrations of the majority of metals showed a decrease with depth, with overall maximum values in the top layers, and that different sampling locations in the Bay received slightly different types of inputs. Three major sources were identified by correlation analysis and principal component analysis: river inputs, metropolitan, and port facilities discharge. Calculation of a pollution load index revealed overall low values, but the enrichment factor values for Pb and Cd were typically high for all cores. The mean concentrations of Cu, Pb, Zn and to some extent Cd exceeded the Effects-Range-Low values in the majority of the cases, indicating that there were possible ecotoxicological risks to organisms in Shantou Bay. -- Highlights: •Metals had downward decrease with overall maximum value at top layers. •River input, metropolitan and port facilities discharge are identified as major sources. •Pb and Cd are mainly enriched metals. •Cu, Pb, Zn and Cd had potential ecotoxicological risks to organisms in Shantou Bay. -- Shantou Bay was polluted by Cd, Cu, Pb and Zn, and showed an increase trend along time. River input, metropolitan and port facilities were identified as their sources based on multi-analysis

  6. Vertical distribution of tritium in core sediment of Mumbai Harbour Bay

    International Nuclear Information System (INIS)

    Rupali, C.K.; Joshi, Vikram; Jha, S.K.; Tripathi, R.M.; Sonali, B.; Priyanka, R.

    2014-01-01

    In the past few years there has been an increasing interest in the study of behavior of tritium in the environment, worldwide many countries have initiated monitoring of organically bound tritium in the environmental samples as part of their radiological assessments. Tritium ( 3 H) is ubiquitous in the aquatic environment and has a various sources of origin. It is transported to the earth's surface via hydrological cycle. 3 H is produced in variety of processes in nuclear power plants. Discharges to aquatic environment from these establishment results in locally enhanced water concentrations. Levels of 3 H have been further elevated due to atmospheric weapons testing between 1952 and 1962. Recent studies have demonstrated significant accumulation of tritium in both organic-rich sediments and food chain. The present study describes the vertical profile of tritium distribution in core sediment collected from Mumbai Harbour Bay (MHB). This will help in better understanding of the biogeochemical behavior and ecological impacts of tritium in the sediment

  7. Lead and Stable Isotopes in Sediments of Babitonga Bay: An Oil Spill Case

    Energy Technology Data Exchange (ETDEWEB)

    Barrosa, V. G.; Oliveiraa, T. M.N.; Vaza, C. [University of UNIVILLE, Department of Environmental Engineering, Joinville, Santa Catarina (Brazil); Zuppi, G. M. [Dipartimento di Scienze Molecolari e Nanosistemi Universita Ca' Foscari, Venezia and Institute of Environmental Geology and Geoengineering, National Research Council, Monterotondo (Italy)

    2013-07-15

    The hydrologic complex of Babitonga Bay (Brazil) forms a vast environmental complex, hosting the last great mangrove bulk of the southern hemisphere. Mangroves are among the most productive ecosystems on earth. The effects of an oil spill were studied in Babitonga Bay using lead and carbon isotopes. Samples of the spilled oil were obtained nine months after the accident, as well as sediment and water samples. Thus, the isotopic composition of the oil allowed the tracing of the environmental pollution. Notwithstanding the delay in time, isotopes of lead and carbon allowed the identification of areas where the presence of the oil can be still detected, permitting assessment of the extent of pollution. Contaminated sediments exhibited an isotopic composition ({sup 206}Pb/{sup 207}Pb and {sup 208}Pb/{sup 206}Pb) close to that of the oil spilled. Moreover {delta}{sup 13}C also permitted the ratification of these results. Others isotopes were used but with no contributions. Conclusions are derived in terms of the source of the pollution in the specific area. (author)

  8. Preliminary assessment of Miramar Petrochemical Harbor as PAH source to Guajará bay (Belém-PA-Brazil surface sediments

    Directory of Open Access Journals (Sweden)

    Silvana do Socorro Veloso Sodré

    Full Text Available Abstract A preliminary study on a petrochemical harbor as a potential source of polycyclic aromatic hydrocarbons (PAH to surface sediments of Guajará bay, located in Belém City, Pará State, Brazil, over the last 10 years is presented here. The 16 priority USEPA PAH were identified and quantified. Surface sediment samples, collected at 5 sites in the bay, near Miramar Petrochemical Harbor (TEMIR, were extracted and analyzed by high performance liquid chromatography with a diode array detector. Total PAH concentration ranged from 533.0 to 3123.3 ng g-1 dry weight with a mean concentration of 1091.9 ng g-1. The most contaminated places were those where muddy sediments were found with highest concentrations of organic matter. The priority PAH with low molecular weight represented 54.4% of the total abundance and indicate that the main source of contamination of the sediments was petrogenic, indicative of the relevant contribution of the petrochemical harbor activity to the input of PAH to Guajará bay. However, pyrolytic PAH coming from fuel combustion, household waste combustion and untreated sewage discharge are also potential contamination sources to this environment.

  9. Spatiotemporal distribution of radioactive cesium released from Fukushima Daiichi Nuclear Power Station in the sediment of Tokyo Bay, Japan

    International Nuclear Information System (INIS)

    Nakagawa, Ryota; Ishida, Masanobu; Baba, Daisuke; Tanimoto, Satomi; Okamoto, Yuichi; Yamazaki, Hideo

    2013-01-01

    The spatial and temporal distribution of "1"3"4Cs and "1"3"7Cs released from Fukushima Daiichi Nuclear Power Station in the Tokyo Bay sediments were investigated. The total radioactivity of "1"3"4Cs and "1"3"7Cs detected in the Tokyo Bay sediment ranged from 240 to 870 Bq/kg-dry in the estuary of Arakawa River, but the activities detected in other sites were about 90 Bq/kg-dry or less. These results suggested that radioactive cesium, which precipitated to the ground, was carried to the river along with clay particles by rainfall and transported to the estuary. The vertical distribution of radioactive cesium showed that it invaded deeper than estimated based on the accumulation rate of the sediment. It was described that the vertical distribution of radioactive cesium was affected by physical mixing of sediments by tidal current, flood, and bioturbation of benthos. (author)

  10. Flux of nitrogen, phosphorus, and suspended sediment from the Susquehanna River Basin to the Chesapeake Bay during Tropical Storm Lee, September 2011, as an indicator of the effects of reservoir sedimentation on water quality

    Science.gov (United States)

    Hirsch, Robert M.

    2012-01-01

    Concentrations of nitrogen, phosphorus, and suspended sediment are measured at the U.S. Geological Survey streamgage at Conowingo Dam at the downstream end of the Susquehanna River Basin in Maryland, where the river flows into the Chesapeake Bay. During the period September 7-15, 2011, in the aftermath of Tropical Storm Lee, concentrations of these three constituents were among the highest ever measured at this site. These measurements indicate that sediment-storage processes behind the three dams on the lower Susquehanna River are evolving. In particular, they indicate that scouring of sediment (and the nitrogen and phosphorus attached to that sediment) may be increasing with time. Trends in flow-normalized fluxes at the Susquehanna River at Conowingo, Maryland, streamgage during 1996-2011 indicate a 3.2-percent decrease in total nitrogen, but a 55-percent increase in total phosphorus and a 97-percent increase in suspended sediment. These large increases in the flux of phosphorus and sediment from the Susquehanna River to the Chesapeake Bay have occurred despite reductions in the fluxes of these constituents from the Susquehanna River watershed upstream from the reservoirs. Although the Tropical Storm Lee flood event contributed about 1.8 percent of the total streamflow from the Susquehanna River to the Chesapeake Bay over the past decade (water years 2002-11), it contributed about 5 percent of the nitrogen, 22 percent of the phosphorus, and 39 percent of the suspended sediment during the same period. These results highlight the importance of brief high-flow events in releasing nitrogen, phosphorus, and sediment derived from the Susquehanna River watershed and stored in the Conowingo Reservoir to the Chesapeake Bay.

  11. Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2011–13

    Science.gov (United States)

    Buchanan, Paul A.; Downing-Kunz, Maureen; Schoellhamer, David H.; Shellenbarger, Gregory; Weidich, Kurt

    2014-01-01

    The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay. The San Francisco Bay area is home to millions of people, and the bay teems with both resident and migratory wildlife, plants, and fish. Fresh water mixes with salt water in the bay, which is subject both to riverine and marine (tides, waves, influx of salt water) influences. To understand this environment, the USGS, along with its partners, has been monitoring the bay’s waters continuously since 1988. Several water-quality variables are of particular importance to State and Federal resource managers and are monitored at key locations throughout the bay. Salinity, which indicates the relative mixing of fresh and ocean waters in the bay, is derived from specific conductance measurements. Water temperature, along with salinity, affects the density of water, which causes gravity driven circulation patterns and stratification in the water column. Turbidity is measured using light-scattering from suspended solids in water, and is used as a surrogate for suspended-sediment concentration (SSC). Suspended sediment often carries adsorbed contaminants; attenuates sunlight in the water column; deposits on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; and deposits in ports and shipping channels, which can necessitate dredging. Dissolved oxygen, which is essential to a healthy ecosystem, is a fundamental indicator of water quality, and its concentration is affected by water temperature, salinity, ecosystem metabolism, tidal currents, and wind. Tidal currents in the bay reverse four times a day, and wind direction and intensity typically change on a daily cycle: consequently, salinity, water temperature, suspendedsediment concentration, and dissolvedoxygen concentration vary spatially and temporally throughout the bay, and continuous measurements are needed to observe these changes. The purpose of this fact sheet

  12. A biological effects monitoring survey of Cardigan Bay using flatfish histopathology, cellular biomarkers and sediment bioassays: findings of the Prince Madog Prize 2003.

    Science.gov (United States)

    Lyons, Brett P; Stentiford, Grant D; Bignell, John; Goodsir, Freya; Sivyer, David B; Devlin, Michelle J; Lowe, Dave; Beesley, Amanda; Pascoe, Christine K; Moore, Mike N; Garnacho, Eva

    2006-07-01

    Cardigan Bay on the western coast of the UK is considered a pristine location with much of its coastal and marine habitats protected under various national and EC Directives. Despite this, populations of the flatfish dab (Limanda limanda) captured from Cardigan Bay display elevated levels of liver tumours relative to the background prevalence of the disease. This study describes the findings of a research cruise that took place during November 2003 to assess the prevalence of tumours in dab from selected sites in and around Cardigan Bay. In addition, potential causative mechanisms were investigated via measurement of a range of end points (including composition and abundance of benthic and phytoplankton communities, sediment toxicity and cellular biomarkers of genotoxicity) from sediment, water and biota samples. Fish captured from South Cardigan Bay displayed a relatively higher prevalence of liver tumours compared to those captured from Red Wharf Bay. Hepatocellular adenoma (8% and 2%, respectively) and hepatocellular foci of cell alteration (18% and 6%, respectively) were most prevalent in South Cardigan Bay. Analysis of the sediment failed to distinguish any differences in toxicity between the two sampling sites. However, DNA strand breaks in red blood cells of dab were significantly higher (p < 0.05) in fish collected from Red Warf Bay compared with those sampled at Cardigan Bay. The alignment of biological effects measures via such integrated cruise programs are discussed. This work was partly funded under the auspices of the 2003 Prince Madog Prize.

  13. Temporal and spatial distributions of contaminants in sediments of Santa Monica Bay, California

    Science.gov (United States)

    Bay, S.M.; Zeng, E.Y.; Lorenson, T.D.; Tran, K.; Alexander, Corrine

    2003-01-01

    Contaminant inputs from wastewater discharge, a major source of contamination to Santa Monica Bay (SMB), have declined drastically during the last three decades as a result of improved treatment processes and better source control. To assess the concomitant temporal changes in the SMB sediments, a study was initiated in June 1997, in which 25 box cores were collected using a stratified random sampling design. Five sediment strata corresponding to the time intervals of 1890-1920, 1932-1963, 1965-1979, 1979-1989, and 1989-1997 were identified using 210Pb dating techniques. Samples from each stratum were analyzed for metals, 1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites (DDTs), polychlorinated biphenyls (PCBs), and total organic carbon (TOC). Samples from the 1965-1979, 1979-1989, and 1989-1997 strata were also analyzed for polycyclic aromatic hydrocarbons (PAHs) and linear alkylbenzenes (LABs). Sediment metal concentrations increased from 1890-1979 and were similar during the time intervals of 1965-1979, 1979-1989, and 1989-1997, although the mass emissions of trace metals from sewage inputs declined substantially during the same time period. Trace organic contamination in SMB was generally highest in sediments corresponding to deposition during the years of 1965-1979 or 1979-1989 and showed a decline in concentration in the 1989-1997 stratum. Temporal trends of contamination were greatest in sediments collected from areas near the Hyperion Treatment Plant (HTP) outfall system and on the slope of Redondo Canyon. The highest contaminant concentrations were present in sediments near the HTP 7-mile outfall in the 1965-1979 stratum. Elevated trace metal and organic concentrations were still present in the 1989-1997 stratum of most stations, suggesting that sediment contaminants have moved vertically in the sediment column since sludge discharges from the 7-mile outfall (a dominant source of contamination to the bay) ceased in 1987. The

  14. Modern sedimentary environments in a large tidal estuary, Delaware Bay

    Science.gov (United States)

    Knebel, H.J.

    1989-01-01

    Data from an extensive grid of sidescan-sonar records reveal the distribution of sedimentary environments in the large, tidally dominated Delaware Bay estuary. Bathymetric features of the estuary include large tidal channels under the relatively deep (> 10 m water depth) central part of the bay, linear sand shoals (2-8 m relief) that parallel the sides of the tidal channels, and broad, low-relief plains that form the shallow bay margins. The two sedimentary environments that were identified are characterized by either (1) bedload transport and/or erosion or (2) sediment reworking and/or deposition. Sand waves and sand ribbons, composed of medium to coarse sands, define sites of active bedload transport within the tidal channels and in gaps between the linear shoals. The sand waves have spacings that vary from 1 to 70 m, amplitudes of 2 m or less, and crestlines that are usually straight. The orientations of the sand waves and ribbons indicate that bottom sediment movement may be toward either the northwest or southeast along the trends of the tidal channels, although sand-wave asymmetry indicates that the net bottom transport is directed northwestward toward the head of the bay. Gravelly, coarse-grained sediments, which appear as strongly reflective patterns on the sonographs, are also present along the axes and flanks of the tidal channels. These coarse sediments are lag deposits that have developed primarily where older strata were eroded at the bay floor. Conversely, fine sands that compose the linear shoals and muddy sands that cover the shallow bay margins appear mainly on the sonographs either as smooth featureless beds that have uniform light to moderate shading or as mosaics of light and dark patches produced by variations in grain size. These acoustic and textural characteristics are the result of sediment deposition and reworking. Data from this study (1) support the hypothesis that bed configurations under deep tidal flows are functions of current

  15. Sediment transport patterns in the San Francisco Bay Coastal System from cross-validation of bedform asymmetry and modeled residual flux

    Science.gov (United States)

    Barnard, Patrick L.; Erikson, Li H.; Elias, Edwin P.L.; Dartnell, Peter; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    The morphology of ~ 45,000 bedforms from 13 multibeam bathymetry surveys was used as a proxy for identifying net bedload sediment transport directions and pathways throughout the San Francisco Bay estuary and adjacent outer coast. The spatially-averaged shape asymmetry of the bedforms reveals distinct pathways of ebb and flood transport. Additionally, the region-wide, ebb-oriented asymmetry of 5% suggests net seaward-directed transport within the estuarine-coastal system, with significant seaward asymmetry at the mouth of San Francisco Bay (11%), through the northern reaches of the Bay (7–8%), and among the largest bedforms (21% for λ > 50 m). This general indication for the net transport of sand to the open coast strongly suggests that anthropogenic removal of sediment from the estuary, particularly along clearly defined seaward transport pathways, will limit the supply of sand to chronically eroding, open-coast beaches. The bedform asymmetry measurements significantly agree (up to ~ 76%) with modeled annual residual transport directions derived from a hydrodynamically-calibrated numerical model, and the orientation of adjacent, flow-sculpted seafloor features such as mega-flute structures, providing a comprehensive validation of the technique. The methods described in this paper to determine well-defined, cross-validated sediment transport pathways can be applied to estuarine-coastal systems globally where bedforms are present. The results can inform and improve regional sediment management practices to more efficiently utilize often limited sediment resources and mitigate current and future sediment supply-related impacts.

  16. U- and Th-series nuclides in settling particles: implications to sediment transport through surface waters and interior ocean

    International Nuclear Information System (INIS)

    Sarin, M.M.

    2012-01-01

    The Bay of Bengal is a unique ocean basin receiving large quantities of fresh water and sediment supply from several rivers draining the Indian subcontinent. The annual flux of suspended sediments discharged into the Bay of Bengal is one billion tons, about one-tenth of the global sediment discharge into the ocean. The water and sediment discharge to the Bay, show significant seasonal variation, with maximum transport coinciding with the SW-monsoon (July-September). Earlier studies on the distribution of clay minerals in sediments have led to the suggestion that the sediments of the western Bengal Fan are mainly derived from the Peninsular rivers, whereas rest of the Fan sediments is influenced by the Himalayan rivers. Settling fluxes of particulate matter through the water column of the Bay of Bengal show seasonal trends resulting from monsoon enhanced sediment supply via rivers and biological processes in the water column. It is, thus, important to understand the influence of the seasonally varying particle fluxes on the solute-particle interactions and chemical scavenging processes in the surface and deep waters of the Bay of Bengal. In this context, measurements of U- and Th-series nuclides in the settling particles are most relevant. The radionuclide fluxes ( 230 Th, 228 Th and 210 Pb) in the settling particles provide insight into the role of their removal by vertical particle flux and/or lateral transport (removal at the ocean boundaries). A study carried out in the Northern Bay of Bengal documents that the authigenic flux of 230 Th, as measured in sediment trap samples from deep waters, is balanced by its production in the overhead water column. The sediment mass flux, Al and 228 Th fluxes are similar in the settling particles through shallow and deep waters, suggesting predominant removal by vertical particle flux in the North Bay of Bengal. In the Central Bay, particulate mass, Al and 228 Th fluxes are higher in the trap material from deep waters relative

  17. Holocene evolution of Apalachicola Bay, Florida

    Science.gov (United States)

    Osterman, L.E.; Twichell, D.C.; Poore, R.Z.

    2009-01-01

    A program of geophysical mapping and vibracoring was conducted to better understand the geologic evolution of Apalachicola Bay. Analyses of the geophysical data and sediment cores along with age control provided by 34 AMS 14C dates on marine shells and wood reveal the following history. As sea level rose in the early Holocene, fluvial deposits filled the Apalachicola River paleochannel, which extended southward under the central part of the bay and seaward across the continental shelf. Sediments to either side of the paleochannel contain abundant wood fragments, with dates documenting that those areas were forested at 8,000 14C years b.p. As sea level continued to rise, spits formed of headland prodelta deposits. Between ???6,400 and ???2,500 14C years b.p., an Apalachicola prodelta prograded and receded several times across the inner shelf that underlies the western part of the bay. An eastern deltaic lobe was active for a shorter time, between ???5,800 and 5,100 14C years b.p. Estuarine benthic foraminiferal assemblages occurred in the western bay as early as 6,400 14C years b.p., and indicate that there was some physical barrier to open-ocean circulation and shelf species established by that time. It is considered that shoals formed in the region of the present barrier islands as the rising sea flooded an interstream divide. Estuarine conditions were established very early in the post-glacial flooding of the bay. ?? 2009 US Government.

  18. Does centennial morphodynamic evolution lead to higher channel efficiency in San Pablo Bay, California?

    Science.gov (United States)

    van der Wegen, M.; Jaffe, B.E.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Measured bathymetries on 30 year interval over the past 150 years show that San Pablo Bay experienced periods of considerable deposition followed by periods of net erosion. However, the main channel in San Pablo Bay has continuously narrowed. The underlying mechanisms and consequences of this tidal channel evolution are not well understood. The central question of this study is whether tidal channels evolve towards a geometry that leads to more efficient hydraulic conveyance and sediment throughput. We applied a hydrodynamic process-based, numerical model (Delft3D), which was run on 5 San Pablo Bay bathymetries measured between 1856 and 1983. Model results shows increasing energy dissipation levels for lower water flows leading to an approximately 15% lower efficiency in 1983 compared to 1856. During the same period the relative seaward sediment throughput through the San Pablo Bay main channel increased by 10%. A probable explanation is that San Pablo Bay is still affected by the excessive historic sediment supply. Sea level rise and Delta surface water area variations over 150 years have limited effect on the model results. With expected lower sediment concentrations in the watershed and less impact of wind waves due to erosion of the shallow flats, it is possible that energy dissipations levels will decrease again in future decades. Our study suggests that the morphodynamic adaptation time scale to excessive variations in sediment supply to estuaries may be on the order of centuries.

  19. The Vertical Distribution of Sediment Archaeal Community in the “Black Bloom” Disturbing Zhushan Bay of Lake Taihu

    Science.gov (United States)

    Fan, Xianfang; Xing, Peng

    2016-01-01

    Using the Illumina sequencing technology, we investigated the vertical distribution of archaeal community in the sediment of Zhushan Bay of Lake Taihu, where the black bloom frequently occurred in summer. Overall, the Miscellaneous Crenarchaeotal Group (MCG), Deep Sea Hydrothermal Vent Group 6 (DHVEG-6), and Methanobacterium dominated the archaeal community. However, we observed significant difference in composition of archaeal community among different depths of the sediment. DHVEG-6 dominated in the surface layer (0–3 cm) sediment. Methanobacterium was the dominating archaeal taxa in the L2 (3–6 cm) and L3 (6–10) sediment. MCG was most abundant in the L4 (10–15 cm) and L5 (15–20 cm) sediment. Besides, DHVEG-6 was significantly affected by the concentration of total phosphorus (TP). And loss on ignition (LOI) was an important environmental factor for Methanobacterium. As the typical archaeal taxa in the surface layer sediment, DHVEG-6 and Methanobacterium might be more adapted to abundant substrate supply from cyanobacterial blooms and take active part in the biomass transformation. We propose that DHVEG-6 and Methanobacterium could be the key archaeal taxa correlated with the “black bloom” formation in Zhushan Bay. PMID:26884723

  20. Toxic evaluations of sediments in Tokyo Bay, Japan, using Japanese medaka embryos.

    Science.gov (United States)

    Uno, Seiichi; Kokushi, Emiko; Kawano, Machi; McElroy, Anne E; Koyama, Jiro

    2017-12-01

    Toxic risks of sediments collected from seven sites in Tokyo Bay were evaluated using Japanese medaka embryos. Those sediments with slight pore water were placed in grass petri dishes without overlying water. The most remarkable effect in the field sediment was to cause hatching delay in embryos, and the longest time until hatching took was 12.5 ± 1.6 days post-fertilization (dpf), although that in control group was 10.1 ± 0.7 dpf. A significant delay in hatching was observed at four sites. Because total carbon concentrations were relatively high in sediments at three of these four sites, several chemicals were expected to be residues in these sites and could cause their delay. Although extreme mortality was not observed at all sites, sediments collected from the site close to Kawasaki city induced 10 % mortality. Polycyclic aromatic hydrocarbon (PAH) concentrations were remarkably high at this site compared with other sites, and thus PAH toxicities could be causing the mortality. Concentration of heavy metals such as cadmium, copper, lead, and zinc in sediments were also determined, but no clear relationship was found between toxicities to embryos and the distribution of their concentrations.

  1. Geochemistry of organic carbon and nitrogen in surface sediments of coastal Bohai Bay inferred from their ratios and stable isotopic signatures

    International Nuclear Information System (INIS)

    Gao Xuelu; Yang Yuwei; Wang Chuanyuan

    2012-01-01

    Total organic carbon (TOC), total nitrogen (TN) and their δ 13 C and δ 15 N values were determined for 42 surface sediments from coastal Bohai Bay in order to determine the concentration and identify the source of organic matter. The sampling sites covered both the marine region of coastal Bohai Bay and the major rivers it connects with. More abundant TOC and TN in sediments from rivers than from the marine region reflect the situation that most of the terrestrial organic matter is deposited before it meets the sea. The spatial variation in δ 13 C and δ 15 N signatures implies that the input of organic matter from anthropogenic activities has a more significant influence on its distribution than that from natural processes. Taking the area as a whole, surface sediments in the marine region of coastal Bohai Bay are dominated by marine derived organic carbon, which on average accounts for 62 ± 11% of TOC.

  2. Interpretation FTIR spectrum of seawater and sediment in the Ambon Bay (TAD)

    Science.gov (United States)

    Patty, Diana Julaidy; Loupatty, Grace; Sopalauw, Fitria

    2017-01-01

    Research has done to interpretated FTIR spectrum of seawaters and sediment of the Ambon Bay (TAD). Analysis of samples of sediment and seawater using FTIR spectroscopy. The results showed the sand sediment samples identified Stretch bond OH group (3600-3500 cm-1), N-H Stretch (3400-3300 cm-1), C≡N (2250 cm-1), and NH bending (1640 to 1550 cm-1). And for seawater samples identified bonding group that is N-H Stretch (3400-3350 cm-1), N-H bending (1640 to 1550 cm-1) and C=O (1670-1640 cm-1). The existence of functional groups, carbonyl (C=O), alcohol (OH), carboxyl (COOH) can cause the complexation of metal cations. And the results showed analysis group N-O bond-containing compounds Nitro indicate heavy metal content of Lead (Pb) and group N-H bond-containing compound Amina indicate heavy metal content of Cadmium (Cd).

  3. Subsoil erosion dominates the supply of fine sediment to rivers draining into Princess Charlotte Bay, Australia.

    Science.gov (United States)

    Olley, Jon; Brooks, Andrew; Spencer, John; Pietsch, Timothy; Borombovits, Daniel

    2013-10-01

    The Laura-Normanby River (catchment area: 24,350 km(2)), which drains into Princess Charlotte Bay, has been identified in previous studies as the third largest contributor of sediment to the Great Barrier Reef World Heritage Area. These catchment scale modelling studies also identified surface soil erosion as supplying >80% of the sediment. Here we use activity concentrations of the fallout radionuclides (137)Cs and (210)Pbex to test the hypothesis that surface soil erosion dominates the supply of fine (river systems draining into Princess Charlotte Bay. Our results contradict these previous studies, and are consistent with channel and gully erosion being the dominant source of fine sediment in this catchment. The hypothesis that surface soil erosion dominates the supply of fine sediment to Princess Charlotte Bay is rejected. River sediment samples were collected using both time-integrated samplers and sediment drape deposits. We show that there is no detectable difference in (137)Cs and (210)Pbex activity concentrations between samples collected using these two methods. Two methods were also used to collect samples to characterise (137)Cs and (210)Pbex concentrations in sediment derived from surface soil erosion; sampling of surface-wash deposits and deployment of surface runoff traps that collected samples during rain events. While there was no difference in the (137)Cs activity concentrations for samples collected using these two methods, (210)Pbex activity concentrations were significantly higher in the samples collected using the runoff traps. The higher (210)Pbex concentrations are shown to be correlated with loss-on-ignition (r(2) = 0.79) and therefore are likely to be related to higher organic concentrations in the runoff trap samples. As a result of these differences we use a three end member mixing model (channel/gully, hillslope surface-wash and hillslope runoff traps) to determine the relative contribution from surface soil erosion. Probability

  4. Marine meiofauna, carbon and nitrogen mineralization in sandy and soft sediments of Disko Bay, West Greenland

    DEFF Research Database (Denmark)

    Rysgaard, S.; Christensen, P.B.; Sørensen, Martin Vinther

    2000-01-01

    Organic carbon mineralization was studied in a shallow-water (4 m), sandy sediment and 2 comparatively deep-water (150 and 300 m), soft sediments in Disko Bay, West Greenland. Benthic microalgae inhabiting the shallow-water locality significantly affected diurnal O-2 conditions within the surface...... is regulated primarily by the availability of organic matter and not by temperature. The shallow-water sediment contained a larger meiofauna population than the deep-water muddy sediments. Crustacean nauplia dominated the upper 9 mm while nematodes dominated below. A typical interstitial fauna of species...... layers of the sediment. Algal photosynthetic activity and nitrogen uptake reduced nitrogen effluxes and denitrification rates. Sulfate reduction was the most important pathway for carbon mineralization in the sediments of the shallow-water station. In contrast, high bottom-water NO3- concentrations...

  5. Application of 210Pb-derived sedimentation rates and dinoflagellate cyst analyses in understanding Pyrodinium bahamense harmful algal blooms in Manila Bay and Malampaya Sound, Philippines.

    Science.gov (United States)

    Sombrito, E Z; Bulos, A dM; Sta Maria, E J; Honrado, M C V; Azanza, Rhodora V; Furio, Elsa F

    2004-01-01

    The number of areas affected by toxic harmful algal bloom (HAB) in the Philippines has been increasing since its first recorded occurrence in 1983. Thus far, HAB has been reported in about 20 areas in the Philippines including major fishery production areas. The HAB-causing organism (Pyrodinium bahamense var. compressum) produces a cyst during its life cycle. Pyrodinium cysts which are deposited in the sediment column may play a role in initiating a toxic bloom. 210Pb-derived sedimentation rate studies in the two important fishing grounds of Manila Bay and Malampaya Sound, Palawan have shown that Pyrodinium cysts may have been present in the sediment even before the first recorded toxic algal bloom in these areas. High sedimentation rates (approximately 1 cm/year) have been observed in the northern and western parts of Manila Bay. The results indicate that the sedimentation processes occurring in these bays would require subsurface cyst concentration analysis in evaluating the potential of an area to act as seed bed.

  6. Application of 210Pb-derived sedimentation rates and dinoflagellate cyst analyses in understanding Pyrodinium bahamense harmful algal blooms in Manila Bay and Malampaya Sound, Philippines

    International Nuclear Information System (INIS)

    Sombrito, E.Z.; Bulos, A.M.; Sta Maria, E.J.; Honrado, M.C.V.; Azanza, Rhodora V.; Furio, Elsa F.

    2004-01-01

    The number of areas affected by toxic harmful algal bloom (HAB) in the Philippines has been increasing since its first recorded occurrence in 1983. Thus far, HAB has been reported in about 20 areas in the Philippines including major fishery production areas. The HAB-causing organism (Pyrodinium bahamense var. compressum) produces a cyst during its life cycle. Pyrodinium cysts which are deposited in the sediment column may play a role in initiating a toxic bloom. 210 Pb-derived sedimentation rate studies in the two important fishing grounds of Manila Bay and Malampaya Sound, Palawan have shown that Pyrodinium cysts may have been present in the sediment even before the first recorded toxic algal bloom in these areas. High sedimentation rates (approximately 1 cm/year) have been observed in the Northern and Western parts of Manila Bay. The results indicate that the sedimentation processes occurring in these bays would require subsurface cyst concentration analysis in evaluating the potential of an area to act as sea bed

  7. Photobacterium marinum sp. nov., a marine bacterium isolated from a sediment sample from Palk Bay, India

    Digital Repository Service at National Institute of Oceanography (India)

    Srinivas, T.N.R.; VijayaBhaskar, Y.; Bhumika, V.; AnilKumar, P.

    The novel, cream colored, Gram-staining-negative, rod-shaped, motile bacteria, designated strains AK15 sup(T) and AK18, were isolated from sediment samples collected from Palk Bay, India. Both strains were positive for arginine dihydrolase, lysine...

  8. Application of {sup 137}Cs and {sup 210}Pb radionuclides to determine sedimentation rates of recent sediments from Admiralty Bay, Antarctica Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Mylene Giseli do; Martins, Cesar de Castro [Universidade Federal do Parana (UFPR), Pontal do Parana, PR (Brazil). Centro de Estudos do Mar (CEM); Figueira, Rubens C.L.; Montone, Rosalinda C.; Mahiques, Michel M. de; Tessler, Moyses G., E-mail: rfigueira@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. Oceanografico. Dept. de Oceanografia Fisica, Quimica e Geologica; Vendrame, Antonio C. [Universidade Cruzeiro do Sul, Sao Paulo, SP (Brazil)

    2009-07-01

    Studies about natural and artificial radionuclides in areas such as the Antarctic are key to understand natural and dynamic processes in marine environments. These studies are important to determine levels of radioactive elements and local sedimentation rates. Five marine sediment cores were collected in different points of Admiralty Bay, in the Antarctic Peninsula. The purpose of this study was to determine {sup 137}Cs, {sup 226}Ra and {sup 210}Pb and sedimentation rates at each site. {sup 137}Cs, {sup 210}Pb and {sup 226}Ra were assayed by gamma-counting through direct measurement of the peak at 661 keV, 47 keV and 609 keV, respectively. Sedimentation rates were obtained by {sup 137}Cs and {sup 210}Pb (CIC and CRS). The activities for {sup 137}Cs ranged from 0.84 to 7.09 Bq kg{sup -1}; to {sup 226}Ra from 6.77 to 31.07 Bq kg{sup -1} for {sup 210}Pb ranged from 1.10 to 36.90 Bq kg{sup -1}. The sedimentation rates obtained by the three models ranged from 0.11+-0.01 cm y{sup -1} to 0.46+-0.05 cm y{sup -1}. The levels of {sup 137}Cs registered in this study, as well as in other studies in the Antarctic region indicate that global fallout is the main cause of artificial radionuclides present in this environment, since the Antarctic has not suffered a direct action of human activities that released radioactive elements. The possible grain size variations that occur in the studied points of Admiralty Bay may explain the differences found in the vertical distribution of radionuclides, because of the different values of sedimentation rates and respective dating determined in their profiles. (author)

  9. Metal pollution in a contaminated bay: Relationship between metal geochemical fractionation in sediments and accumulation in a polychaete

    International Nuclear Information System (INIS)

    Fan, Wenhong; Xu, Zhizhen; Wang, Wen-Xiong

    2014-01-01

    Jinzhou Bay in Northern China has been seriously contaminated with metals due to the impacts of smelting activities. In this study, we investigated the relationship between metal accumulation in a deposit-feeding polychaete Neanthes japonica and metal concentration and geochemical fractionation (Cd, Cu, Pb, Zn and Ni) in sediments of Jinzhou Bay. Compared with the historical data, metals in the more mobile geochemical fraction (exchangeable and carbonate fractions) were gradually partitioned into the more stable fraction (Fe–Mn oxides) over time. Metal concentration and geochemical fractionation in sediment significantly affected metal bioavailability and accumulation in polychaetes, except for Ni. Metal accumulation in polychaetes was significantly influenced by Fe or Mn content, and to a lesser degree by organic matter. Prediction of metal bioaccumulation in polychaetes was greatly improved by normalizing metal concentrations to Mn content in sediment. The geochemical fractionation of metals in sediments including the exchangeable, organic matter and Fe–Mn oxides were important in controlling the sediment metal bioavailability to polychaetes. - Highlights: • Metals in contaminated sediments gradually partitioned into the more stable phase over time. • Metal accumulation in polychaetes was more significantly influenced by Fe/Mn content than by organic matter. • Prediction of metal bioaccumulation greatly improved by normalizing metals to Mn content in sediment. • Metals in exchangeable, organic matter and Fe–Mn oxides were important in controlling their bioavailability. - Prediction of metal bioaccumulation in polychaetes was significantly improved by normalizing metal concentrations to Mn content in sediment

  10. Butyltin speciation in sediments from Todos os Santos Bay (Bahia, Brazil by GC-PFPD

    Directory of Open Access Journals (Sweden)

    Juliana Feitosa Felizzola

    2008-01-01

    Full Text Available Butyltin compounds were investigated in surface sediments from 17 stations in Todos os Santos Bay. Analytical conditions for organotin determination in marine sediments were optimized for GC with pulsed flame photometric detection. Detection limits were: 5.4 µg kg-1 for TBT; 0.2 µg kg-1 for DBT; and 2.1 µg kg-1 for MBT, using a 610-nm filter. In general, TBT concentrations were low and in the range of

    sediments. The presence of paint particles in the sediments and degradation in the water column during resuspension events followed by removal of the more soluble DBT and MBT may explain these observations.

  11. Petroleum hydrocarbon concentrations in marine sediments along Chennai Coast, Bay of Bengal, India.

    Science.gov (United States)

    Venkatachalapathy, R; Veerasingam, S; Ramkumar, T

    2010-10-01

    The spatial and temporal distribution of petroleum hydrocarbons (PHC) in marine sediments along the Chennai coast, Bay of Bengal was quantified by Ultra-Violet Fluorescence (UVF) Spectroscopy. The concentration of PHC in surface sediments varied from 1.88 to 39.76 ppm. The highest values obtained in the northern part of the study area, where shipping activities and land-based waste waters disposed into sea through the rivers like Kuvam and Adayar. The Adayar (7.26-16.83 ppm) and Kuvam (5.5-39.72 ppm) cores reveal a clear horizon of increase in PHC above 50 and 35 cm respectively. PHC values showed a decreasing pattern with depth in all sediment cores suggesting the excess anthropogenic loading occurring in the recent past. The present study revealed that the PHC values of Chennai coastal sediments are lower than the values reported from selected costal areas including the sediment of the Mumbai coast (7.6-42.8 ppm), Arabian Sea. The results will be useful for pollution monitoring program along the coastal region and also to check the level of petroleum hydrocarbons in marine sediments.

  12. The history of metals pollution in Narragansett Bay as recorded by salt-marsh sediments

    International Nuclear Information System (INIS)

    Bricker, S.B.

    1990-01-01

    Sediment cores from 5 salt marshes from the head to the mouth of Narragansett Bay and an additional core from a lagoon on Block Island Sound were analyzed for 210 Pb and for Fe, Mn, Cu, Pb, Cr, Zn, Ag, and Ni in order to examine the long-term variation of metal inputs to Narragansett Bay. The 210 Pb results were used to determine accretion rates for each core. Distributions of Fe and Mn were used as indicators of chemical conditions of sediment cores and Cu, Pb, Cr, Zn, Ag, and Ni distributions with time were compared with known or estimated source inputs to examine the long-term variation of pollutant metal inputs to Narragansett Bay. At one location, duplicate cores were sampled to look at variability within a marsh. At another location, a high marsh, receiving predominantly atmospheric inputs and a low marsh, receiving waterborne and atmospheric inputs, were sampled so that atmospheric and tidal contributions could be determined. A comparison was made of the distributions of metals in bay cores and in the lagoon core. All the Rhode Island marshes accrete at rates equal to or greater than the local rise in sea level. Based on the 210 Pb chronologies, pollutant metals began to increase in the mid to late 1800s, corresponding to coal burning emissions to the atmosphere. Steeper increases in the 1900s reflect industrial and sewage discharges. Maximum concentrations were reached in the 1950s and have declined almost continuously since then. Observed reductions were attributable to implementation of and improvements to sewage treatment, and controls on atmospheric emissions

  13. Heavy metal pollution and Pb isotopic tracing in the intertidal surface sediments of Quanzhou Bay, southeast coast of China

    International Nuclear Information System (INIS)

    Yu, Ruilian; Zhang, Weifang; Hu, Gongren; Lin, Chengqi; Yang, Qiuli

    2016-01-01

    Concentrations of 16 heavy metals and Pb isotopic ratios in the intertidal surface sediments of Quanzhou Bay were determined to study the pollution level of heavy metals and the sources of Pb. The results showed that most concentrations of Cd, Sn, Mn, Cu, Zn, Cr, Pb, Hg, Ni, Co, Cs, Fe and V were higher than the background values, while most concentrations of Ti, Sb and Sr were lower than the background values. The mean concentrations of Cu, Zn, Pb, Cr and Cd exceeded the first-grade criteria of Chinese marine sediment quality. The geo-accumulation indexes revealed that the sediments had been polluted by some heavy metals. The results of Pb isotopic tracing indicated that the total Pb in the sediments were mainly from parent material, industrial emission and vehicle exhaust with the mean contributions of 38.2%, 51.3% and 10.5%, respectively, calculated by a three-end-member model of Pb isotopic ratios. - Highlights: •Level of 16 heavy metals in intertidal surface sediments of Quanzhou Bay was studied. •The sediments had been polluted by some heavy metals including Pb. •Pb isotopic compositions in the sediments and the potential sources were determined. •A three-end member model was applied to estimate the contributions of Pb sources. •Industrial emission was the major anthropogenic Pb contributor in the sediments.

  14. 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.

  15. Modeling the fate of p,p'-DDT in water and sediment of two typical estuarine bays in South China: Importance of fishing vessels' inputs.

    Science.gov (United States)

    Fang, Shu-Ming; Zhang, Xianming; Bao, Lian-Jun; Zeng, Eddy Y

    2016-05-01

    Antifouling paint applied to fishing vessels is the primary source of dichloro-diphenyl-trichloroethane (DDT) to the coastal marine environments of China. With the aim to provide science-based support of potential regulations on DDT use in antifouling paint, we utilized a fugacity-based model to evaluate the fate and impact of p,p'-DDT, the dominant component of DDT mixture, in Daya Bay and Hailing Bay, two typical estuarine bays in South China. The emissions of p,p'-DDT from fishing vessels to the aquatic environments of Hailing Bay and Daya Bay were estimated as 9.3 and 7.7 kg yr(-1), respectively. Uncertainty analysis indicated that the temporal variability of p,p'-DDT was well described by the model if fishing vessels were considered as the only direct source, i.e., fishing vessels should be the dominant source of p,p'-DDT in coastal bay areas of China. Estimated hazard quotients indicated that sediment in Hailing Bay posed high risk to the aquatic system, and it would take at least 21 years to reduce the hazards to a safe level. Moreover, p,p'-DDT tends to migrate from water to sediment in the entire Hailing Bay and Daya Bay. On the other hand, our previous research indicated that p,p'-DDT was more likely to migrate from sediment to water in the maricultured zones located in shallow waters of these two bays, where fishing vessels frequently remain. These findings suggest that relocating mariculture zones to deeper waters would reduce the likelihood of farmed fish contamination by p,p'-DDT. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. 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

  17. Macrofaunal recolonization of copper-contaminated sediments in San Diego Bay.

    Science.gov (United States)

    Neira, Carlos; Mendoza, Guillermo; Porrachia, Magali; Stransky, Chris; Levin, Lisa A

    2015-12-30

    Effects of Cu-loading on macrofaunal recolonization were examined in Shelter Island Yacht Basin (San Diego Bay, California). Sediments with high and low Cu levels were defaunated and Cu-spiked, translocated, and then placed back into the environment. These demonstrated that the alteration observed in benthic communities associated with Cu contamination occurs during initial recolonization. After a 3-month exposure to sediments with varying Cu levels, two primary colonizing communities were identified: (1) a "mouth assemblage" resembling adjacent background fauna associated with low-Cu levels that was more diverse and predominantly dominated by surface- and subsurface-deposit feeders, burrowers, and tube builders, and (2) a "head assemblage" resembling adjacent background fauna associated with high-Cu concentrations, with few dominant species and an increasing importance of carnivores and mobile epifauna. Cu loading can cause reduced biodiversity and lower structural complexity that may last several months if high concentrations persist, with a direct effect on community functioning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Total mercury in water and sediment from Honda Bay area in Palawan

    International Nuclear Information System (INIS)

    Kapauan, A.F.; Kapauan, P.A.; Tan, E.O.; Verceluz, F.P.

    1980-01-01

    This project is intended to pinpoint the sources of mercury contamination from the Honda Bay area in Palawan. Sampling sites were pinpointed which water and sediment samples were to be taken and kept in virgin polyethylene liter bottles. Analytical procedures were applied. The results of the analysis for total mercury content vary cosiderably from ml, less than 0.003 ng/9 to high of 0.419 ng/g with a considerable number of the sample going above the 0.100 ng/g level. Sediment samples also gave similar results, from a low of 0.004 ng/g to value higher than 2 ng/g round the jetty. It can be concluded, therefore, that the area surveyed is contaminated with mercury but not severely so. (author)

  19. Hydrography and bottom boundary layer dynamics: Influence on inner shelf sediment mobility, Long Bay, North Carolina

    Science.gov (United States)

    Davis, L.A.; Leonard, L.A.; Snedden, G.A.

    2008-01-01

    This study examined the hydrography and bottom boundary-layer dynamics of two typical storm events affecting coastal North Carolina (NC); a hurricane and the passages of two small consecutive extratropical storms during November 2005. Two upward-looking 1200-kHz Acoustic Doppler Current Profilers (ADCP) were deployed on the inner shelf in northern Long Bay, NC at water depths of less than 15 m. Both instruments profiled the overlying water column in 0.35 in bins beginning at a height of 1.35 in above the bottom (mab). Simultaneous measurements of wind speed and direction, wave and current parameters, and acoustic backscatter were coupled with output from a bottom boundary layer (bbl) model to describe the hydrography and boundary layer conditions during each event. The bbl model also was used to quantify sediment transport in the boundary layer during each storm. Both study sites exhibited similar temporal variations in wave and current magnitude, however, wave heights during the November event were higher than waves associated with the hurricane. Near-bottom mean and subtidal currents, however, were of greater magnitude during the hurricane. Peak depth-integrated suspended sediment transport during the November event exceeded transport associated with the hurricane by 25-70%. Substantial spatial variations in sediment transport existed throughout both events. During both events, along-shelf sediment transport exceeded across-shelf transport and was related to the magnitude and direction of subtidal currents. Given the variations in sediment type across the bay, complex shoreline configuration, and local bathymetry, the sediment transport rates reported here are very site specific. However, the general hydrography associated with the two storms is representative of conditions across northern Long Bay. Since the beaches in the study area undergo frequent renourishment to counter the effects of beach erosion, the results of this study also are relevant to coastal

  20. Application of {sup 210}Pb-derived sedimentation rates and dinoflagellate cyst analyses in understanding Pyrodinium bahamense harmful algal blooms in Manila Bay and Malampaya Sound, Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Sombrito, E.Z. E-mail: ezsombrito@pnri.dost.gov.ph; Bulos, A.M.; Sta Maria, E.J.; Honrado, M.C.V.; Azanza, Rhodora V.; Furio, Elsa F

    2004-07-01

    The number of areas affected by toxic harmful algal bloom (HAB) in the Philippines has been increasing since its first recorded occurrence in 1983. Thus far, HAB has been reported in about 20 areas in the Philippines including major fishery production areas. The HAB-causing organism (Pyrodinium bahamense var. compressum) produces a cyst during its life cycle. Pyrodinium cysts which are deposited in the sediment column may play a role in initiating a toxic bloom. {sup 210}Pb-derived sedimentation rate studies in the two important fishing grounds of Manila Bay and Malampaya Sound, Palawan have shown that Pyrodinium cysts may have been present in the sediment even before the first recorded toxic algal bloom in these areas. High sedimentation rates (approximately 1 cm/year) have been observed in the Northern and Western parts of Manila Bay. The results indicate that the sedimentation processes occurring in these bays would require subsurface cyst concentration analysis in evaluating the potential of an area to act as sea bed.

  1. Concentrations of heavy metals in sediment and organisms during a harmful algal bloom (HAB) at Kun Kaak Bay, Sonora, Mexico

    International Nuclear Information System (INIS)

    Garcia-Hernandez, Jaqueline; Garcia-Rico, Leticia; Jara-Marini, Martin E.; Barraza-Guardado, Ramon; Hudson Weaver, Amy

    2005-01-01

    In early April 2003, fishermen from Kino Bay Sonora alerted us about a massive die-off of fish and mollusks occurring at Kun Kaak Bay. Phytoplankton samples taken on 17 May 2003 reported the presence of a harmful algal bloom composed of Chatonella marina, Chatonella cf. ovata, Gymnodinium catenatum and Gymnodinium sanguineum. On 22 of May, we collected samples of water, sediment and organisms at the affected area. Physicochemical parameters and nutrients were measured in water samples from different depths. Sediment and benthic organisms were analyzed for Cd, Cu, Zn, Pb and Hg. We found concentrations of heavy metals higher than background levels for this area. Cadmium and Lead concentrations in sediment from the HAB area were up to 6x greater than background levels and Cd in mollusks was 8x greater than regulations allow. A relationship between elevated Cd and Pb concentrations in sediment and the survival of toxic dinoflagellates is suspected

  2. Concentrations of heavy metals in sediment and organisms during a harmful algal bloom (HAB) at Kun Kaak Bay, Sonora, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Hernandez, Jaqueline [Centro de investigacion en Alimentacion y Desarrollo AC (CIAD) Guaymas Unit, Carretera al Varadero Nal. Km 6.6, Apdo. Postal 284, CP 85480 Guaymas, Sonora (Mexico)]. E-mail: jaqueline@cascabel.ciad.mx; Garcia-Rico, Leticia [Centro de investigacion en Alimentacion y Desarrollo AC (CIAD), Carretera a la Victoria Km 0.6, Apdo. Postal 1735, CP 83000 Hermosillo, Sonora (Mexico)]. E-mail: lgarciar@cascabel.ciad.mx; Jara-Marini, Martin E. [Centro de investigacion en Alimentacion y Desarrollo AC (CIAD), Carretera a la Victoria Km 0.6, Apdo. Postal 1735, CP 83000 Hermosillo, Sonora (Mexico)]. E-mail: mjara@cascabel.ciad.mx; Barraza-Guardado, Ramon [Departamento de Investigaciones Cientificas y Tecnologicas de la Universidad de Sonora (DICTUS), Rosales y Ninos Heroes s/n Col. Centro, CP 83000 Hermosillo, Sonora (Mexico)]. E-mail: rbarraza@rtn.uson.mx; Hudson Weaver, Amy [Comunidad y Biodiversidad AC - COBI, Terminacion Bahia de Bacochibampo s/m, Fraccionamiento Lomas de Cortes, CP 85450 Guaymas, Sonora (Mexico)]. E-mail: ahw@cobi.org.mx

    2005-07-01

    In early April 2003, fishermen from Kino Bay Sonora alerted us about a massive die-off of fish and mollusks occurring at Kun Kaak Bay. Phytoplankton samples taken on 17 May 2003 reported the presence of a harmful algal bloom composed of Chatonella marina, Chatonella cf. ovata, Gymnodinium catenatum and Gymnodinium sanguineum. On 22 of May, we collected samples of water, sediment and organisms at the affected area. Physicochemical parameters and nutrients were measured in water samples from different depths. Sediment and benthic organisms were analyzed for Cd, Cu, Zn, Pb and Hg. We found concentrations of heavy metals higher than background levels for this area. Cadmium and Lead concentrations in sediment from the HAB area were up to 6x greater than background levels and Cd in mollusks was 8x greater than regulations allow. A relationship between elevated Cd and Pb concentrations in sediment and the survival of toxic dinoflagellates is suspected.

  3. Concentrations of heavy metals in sediment and organisms during a harmful algal bloom (HAB) at Kun Kaak Bay, Sonora, Mexico.

    Science.gov (United States)

    García-Hernández, Jaqueline; García-Rico, Leticia; Jara-Marini, Martin E; Barraza-Guardado, Ramón; Hudson Weaver, Amy

    2005-07-01

    In early April 2003, fishermen from Kino Bay Sonora alerted us about a massive die-off of fish and mollusks occurring at Kun Kaak Bay. Phytoplankton samples taken on 17 May 2003 reported the presence of a harmful algal bloom composed of Chatonella marina, Chatonella cf. ovata, Gymnodinium catenatum and Gymnodinium sanguineum. On 22 of May, we collected samples of water, sediment and organisms at the affected area. Physicochemical parameters and nutrients were measured in water samples from different depths. Sediment and benthic organisms were analyzed for Cd, Cu, Zn, Pb and Hg. We found concentrations of heavy metals higher than background levels for this area. Cadmium and Lead concentrations in sediment from the HAB area were up to 6x greater than background levels and Cd in mollusks was 8x greater than regulations allow. A relationship between elevated Cd and Pb concentrations in sediment and the survival of toxic dinoflagellates is suspected.

  4. Natural and anthropogenic sources of chemical elements in sediment profiles from the Admiralty Bay, Antarctica

    International Nuclear Information System (INIS)

    Ribeiro, A.P.; Figueira, R.C.L.; Silva, C.R.A.; Franca, E.J.; Mahiques, M.M.; Bicego, M.C.; Montone, R.C.

    2010-01-01

    Full text: The Antarctic Continent and its surrounding Southern Ocean are the least known regions of the world, mainly due to the most unfavorable climatic conditions, in which sampling for environmental studies are quite difficult to be carried out. Admiralty Bay on the King George Island (Antarctica) hosts three research stations, Arctowski, Ferraz and Macchu Picchu, which are operate by Poland, Brazil and Peru, respectively. Therefore, human activities in this region require the use of fossil fuel as an energy source, which is also considered the main source of pollutants in the area. This work investigated the natural and anthropogenic inputs of chemical elements in sediment samples collected close to Ferraz Station, during the 25 th Brazilian Antarctica Expedition in the 2006/2007 austral summer. Total concentrations of As, Zn and Sc were determined in sediment profiles by using the Instrumental Neutron Activation Analysis (INAA). The analytical technique employed to determine the major elements such as Fe, Al, Ca, Mn and Ti was X-ray fluorescence (XRF) spectroscopy. For estimating the sedimentation rate, High Resolution Gamma Ray Spectrometry was applied to determine 137 Cs, after 30 days, to achieve secular equilibrium. According to the enrichment factor and the geochronology analysis, the most relevant enrichment was observed for As in the sediment samples, suggesting the increasing of its content due to the Brazilian activities in the Admiralty Bay. Despite some evidences of anthropogenic contribution, the study indicated low level of environmental risk for this region. (author)

  5. Study of macro and microelements in fish from the Cienfuegos Bay. Relationship with its content in sediments.

    Science.gov (United States)

    Peña-Icart, M; Rodrigues Pereira-Filho, E; Lopes Fialho, L; Nóbrega, J A; Alonso-Hernández, C; Bolaños-Alvarez, Y; Muñoz-Caravaca, A; Pomares-Alfonso, M S

    2017-09-01

    Thirteen microelements (Al, As, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Ti, V, and Zn) and four macroelements (Ca, K, Mg, and Na) were determined in the edible muscle tissue of fish in Cienfuegos Bay. Eight species, Albula vulpes, Diapterus rhombeus, Gerres cinereus, Haemulon carbonarium, Haemulon sciurus, Micropogonias furnieri, Kyphosus sectatrix, and Lutjanus cyanopterus were studied. The total concentrations and extracted concentrations using HCl were also determined in sediments. The quality of the analysis was guaranteed by validating the used analytical methods with certified reference materials of fish and sediments. The high content of macroelements confirmed the importance of fish as a valuable source of food for the local population. New information is provided on bioaccumulation of toxic elements As, Cd, Cu, Zn, and Cr in fish of the bay, with concentrations that overcame the local or international maximum allowable levels for human consumption in most samples analyzed. A high correlation between the content of toxic elements As, Cd, Zn, and macroelement K in fish and its concentration extracted from sediments using the HCl extraction method was observed.

  6. Coastal circulation and sediment dynamics in Maunalua Bay, Oahu, Hawaii, measurements of waves, currents, temperature, salinity, and turbidity; November 2008-February 2009

    Science.gov (United States)

    Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.; Field, Michael E.

    2010-01-01

    High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Maunalua Bay, southern Oahu, Hawaii, during the 2008-2009 winter to better understand coastal circulation, water-column properties, and sediment dynamics during a range of conditions (trade winds, kona storms, relaxation of trade winds, and south swells). A series of bottom-mounted instrument packages were deployed in water depths of 20 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity, and turbidity. These data were supplemented with a series of profiles through the water column to characterize the vertical and spatial variability in water-column properties within the bay. These measurements support the ongoing process studies being done as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Pacific Coral Reef Project; the ultimate goal of these studies is to better understand the transport mechanisms of sediment, larvae, pollutants, and other particles in coral reef settings. Project Objectives The objective of this study was to understand the temporal variations in currents, waves, tides, temperature, salinity and turbidity within a coral-lined embayment that receives periodic discharges of freshwater and sediment from multiple terrestrial sources in the Maunalua Bay. Instrument packages were deployed for a three-month period during the 2008-2009 winter and a series of vertical profiles were collected in November 2008, and again in February 2009, to characterize water-column properties within the bay. Measurements of flow and water-column properties in Maunalua Bay provided insight into the potential fate of terrestrial sediment, nutrient, or contaminant delivered to the marine environment and coral larval transport within the embayment. Such data are useful for providing baseline information for future watershed decisions and for establishing guidelines for

  7. Time trends of perfluorinated compounds from the sediment core of Tokyo Bay, Japan (1950s-2004)

    International Nuclear Information System (INIS)

    Zushi, Yasuyuki; Tamada, Masafumi; Kanai, Yutaka; Masunaga, Shigeki

    2010-01-01

    Perfluorinated compounds (PFCs) were detected in sediment core samples collected in Tokyo Bay to reveal their time trends. The core sample deposited during 1950s-2004 was divided into two- to three-year intervals and the concentrations of 24 types of PFCs were determined. Perfluorooctane sulfonate (PFOS) decreased gradually from the early 1990s and its precursor decreased rapidly in the late 1990s, whereas perfluorooctanoic acid (PFOA) increased rapidly. The observed trends were regarded as a reflection of the shift from perfluorooctyl sulfonyl fluoride (PFOSF)-based products to telomer-based products after the phaseout of PFOSF-based products in 2001. The branched isomers of perfluoroundecanoic acid (PFUnDA) and perfluorotridecanoic acid (PFTrDA) were detected in the sample with its ratio of linear-isomer/branched-isomer concentrations decreasing. In this study, we revealed that the sediment core can serve as a tool for reconstructing the past pollution trend of PFCs and can provide interesting evidence concerning their environmental dynamics and time trend. - This study reports the time trends of the concentrations of 24 species of PFCs, including FTCA, FTUCA and FOSAA, in a sediment core of Tokyo Bay, Japan.

  8. Evaluation of potential relationships between benthic community structure and toxic metals in Laizhou Bay.

    Science.gov (United States)

    Wu, Bin; Song, Jinming; Li, Xuegang

    2014-10-15

    The objective of the present study was to examine the relationships between benthic community structure and toxic metals using bivariate/multivariate techniques at 17 sediment locations in Laizhou Bay, North China. Sediment chemical data were evaluated against geochemical background values and sediment quality guidelines, which identified Cu and As as contaminants of concern with a moderate potential for adverse effects. Benthic community data were subjected to non-metric multidimensional scaling, which generated four groups of stations. Spearman rank correlation was then employed to explore the relationships between the major axes of heavy metals and benthic community structure. However, weak and insignificant correlations were found between these axes, indicating that contaminants of concern may not be the primary explanatory factors. Polychaeta were abundant in southern Laizhou Bay, serving as a warning regarding the health status of the ecosystem. Integrated sediment quality assessment showed sediments from northern central locations were impaired, displaying less diverse benthos and higher metal contamination. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Analysis and dating of Sediments in Montevideo Bay and Silver river

    International Nuclear Information System (INIS)

    Odino, R.; Suarez Antola, R.; Cabral, W.

    1999-01-01

    The present work includes generalities on the River of the Silver, antecedents of studies carried out during the years 1992-1997, in the issuing sub aquatic of Tip Carts, studies about the contamination of silts carried out during the years 1993-1996, studies preliminary of the contamination of silts in the Bay,results obtain,treatment of the data and enrichment factors. In the description of the project it is looked for to obtain reliable data on the state of contamination for heavy metals sedimentation ,velocity and age of the silts of the Bay of Montevideo and the River of the Silver, describe geologic aspects in the area involved in the study, the sampling of silts is planned having present the purpose of the same one that is to say to take samples that represent the characteristics real of silts in the sampling area, X Ray Fluorescence dispersive Energy are used in the analysis of samples, for finish, results and discussion are presented

  10. Over 100 years of environmental change recorded by foraminifers and sediments in a large Gulf of Mexico estuary, Mobile Bay, AL, USA

    Science.gov (United States)

    Osterman, Lisa E.; Smith, Christopher G.

    2012-01-01

    The marine microfauna of Mobile Bay has been profoundly influenced by the development and expansion of the primary shipping channel over the last ˜100 years. Foraminifers and sediments from seven box cores with excess lead-210 chronology document that channel dredging and spoil disposal have altered circulation, reduced estuarine mixing, changed sedimentation patterns, and caused a faunal turnover within the bay. Beginning in the late 1800s, changes in estuarine mixing allowed for greater low-pH freshwater influence in the bay, and ultimately began environmental changes that resulted in the loss of calcareous foraminifers. By the early 1900s, box cores throughout Mobile Bay record a ˜ 100-year trend of increasing calcareous test dissolution that continues to the present. Since the completion of the current shipping channel in the 1950s, restricted tidal flushing and increased terrestrial organic matter, documented by carbon-to-nitrogen ratios, stimulated an increase in agglutinated foraminiferal densities. However, in deeper areas of the bay, hypoxic water has negatively impacted the marine microfauna. Comparisons of the present-day foraminiferal assemblage with foraminifers collected in the early 1970s indicate that the continued biologic loss of calcareous foraminifers in the bay has allowed the introduction of a new agglutinated foraminiferal species into the bay.

  11. Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 2. Sequim Bay clayey silt

    International Nuclear Information System (INIS)

    Schmidt, R.L.

    1982-04-01

    This report describes laboratory experiments in which neutron-activated 347 stainless steel specimens were exposed to clayey silt from Sequim Bay, Washington. The properties and trace metal geochemistry of the sediment and the amounts of corrosion products that were released under oxic and reduced conditions and their distribution among different chemical fractions of the sediment are discussed. The distributions of Cr, Mn, Fe, Ni and Cu among different chemical forms in the Sequim Bay sediment show that DTPA removed <10% of extractable Cr, Fe and Mn, approx. 20% of extractable Ni and approx. 30% of extractable Cu. The inorganic fraction (material soluble in 2.5% acetic acid) accounted for approx. 30% of total extractable Mn and approx. 10% or less of Cr, Fe, Ni and Cu. Major portions of Cr and Cu, and a large amount of Fe were in the organic fraction. Extractable Mn, Fe and Ni were associated with hydrous oxides likely as coatings on the mineral substrate of the sediment. No Co was detectable in any of the extracts

  12. A geochemical record of environmental changes in sediments from Sishili Bay, northern Yellow Sea, China: Anthropogenic influence on organic matter sources and composition over the last 100 years

    International Nuclear Information System (INIS)

    Wang, Yujue; Liu, Dongyan; Richard, Pierre; Li, Xin

    2013-01-01

    Highlights: • Increased TOC and TN in the sediment cores indicated a eutrophic trend since 1975. • Marine organic matter sources dominated in Sishili Bay. • Scallop culture displayed mitigation on eutrophication pressures in Sishili Bay. • Increased fertilizer use well matched eutrophic process in Sishili Bay in 1975. -- Abstract: Total organic carbon (TOC), total nitrogen (TN), δ 13 C and δ 15 N were measured in sediment cores at three sites in Sishili Bay, China, to track the impacts of anthropogenic activities on the coastal environment over the last 100 years. The increased TOC and TN in the upper section of sediment cores indicated a eutrophic process since 1975. In comparison, the TOC and TN in the sediment core near to a scallop aquaculture area displayed a much slower increase, indicating the contribution of scallop aquaculture in mitigating eutrophication. Combined information from δ 13 C, δ 15 N and TOC:TN indicated an increased terrestrial signal, although organic matter sources in Sishili Bay featured a mixture of terrestrial and marine sources, with phytoplankton being dominant. Increased fertilizer use since 1970s contributed to the eutrophic process in Sishili Bay since 1975, and increased sewage discharge from 1990s has added to this process

  13. Polychlorinated biphenyl (PCB) contamination in Galveston Bay, Texas: Comparing concentrations and profiles in sediments, passive samplers, and fish.

    Science.gov (United States)

    Oziolor, Elias M; Apell, Jennifer N; Winfield, Zach C; Back, Jeffrey A; Usenko, Sascha; Matson, Cole W

    2018-05-01

    The industrialized portion of the Houston Ship Channel (HSC) is heavily contaminated with anthropogenic contaminants, most prominent of which are the polychlorinated biphenyls (PCBs). This contamination has driven adaptive evolution in a keystone species for Galveston Bay, the Gulf killifish (Fundulus grandis). We investigated the geographical extent of PCB impacts by sampling 12 sites, ranging from the heavily industrialized upper portion of the HSC to Galveston Island. At each site, PCB concentrations and profiles were determined in three environmental compartments: sediment, water (polyethylene passive samplers), and fish tissue (resident Gulf killifish). We observed a steep gradient of PCB contamination, ranging from 4.00 to 100,000 ng/g organic carbon in sediment, 290-110,000 ng/g lipid in fish, and 4.5-2300 ng/g polyethylene in passive samplers. The PCB congener profiles in Gulf killifish at the most heavily contaminated sites were shifted toward the higher chlorinated PCBs and were highly similar to the sediment contamination profiles. In addition, while magnitude of total PCB concentrations in sediment and total fish contamination levels were highly correlated between sites, the relative PCB congener profiles in fish and passive samplers were more alike. This strong correlation, along with a lack of dependency of biota-sediment accumulation factors with total contamination rates, confirm the likely non-migratory nature of Gulf killifish and suggest their contamination levels are a good site-specific indicator of contamination in the Galveston Bay area. The spatial gradient of PCB contamination in Galveston Bay was evident in all three matrices studied and was observed effectively using Gulf killifish contamination as an environmentally relevant bioindicator of localized contamination in this environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Seasonal, Spatial Distribution and Ecological Risk Assessment of Heavy Metals in Surface Sediments from a Watershed Area in Gonghu Bay in Taihu Lake, China

    Directory of Open Access Journals (Sweden)

    Peifang Wang

    2014-01-01

    Full Text Available Surface sediments from five stations within Gonghu Bay in Taihu Lake, China, were sampled for seasonal and spatial metal contamination analysis variations and ecological risks assessment from April 2009 to January 2010. The Contamination Factor (CF and geo-accumulation index (Igeo indicated that the sediments in Gonghu Bay ranged from unpolluted to moderately polluted, except for Cd. The one-way ANOVA analysis results showed that the Pb, Zn, Cr, and Cu concentrations were higher at station 3 (lake inlet and the Cr, Pb, and Zn concentrations were significantly higher in the spring. Additionally, using BCR¡¦s sequential extraction, the results showed that the fractionated metals Zn and Cd were observed as bioavailable fractions in the sediments, which could have potential moderate mobility in the water system. There was a significant increase in the bioavailable form during winter. The ratio of secondary and primary phrase (RSP decreased according to the order Zn > Cu > Ni > Pb > Cd > Cr. Finally, these results indicated that the sediments of Gonghu Bay were polluted by Cd, Zn, and Cu, which provides a scientific basis for effectively protecting sediments in watershed areas from long-term heavy metal accumulation.

  15. Temporal changes in TBT pollution in water, sediment, and oyster from Jinhae Bay after the total ban in South Korea.

    Science.gov (United States)

    Kim, Nam Sook; Hong, Sang Hee; Yim, Un Hyuk; Shin, Kyung-Hoon; Shim, Won Joon

    2014-09-15

    Temporal change in tributyltin (TBT) levels in Jinhae Bay, which has various TBT sources, was investigated in water, sediments, and oysters from 2003 to 2013 after its total ban in South Korea. The seawater TBT levels decreased over 500-fold from 1995/97 to 2008/09. The oyster TBT levels were about fourfold lower in 2012/13 than in 1995/97. However, the sediment TBT levels did not significantly change, even 10 years after the partial TBT ban on small ships and 7 years after the total TBT ban on all oceangoing vessels in Korea. The total ban of TBT use effectively reduced water and oyster TBT levels in Jinhae Bay, but TBT levels in water, oysters, and sediment remained above the global environmental quality standards established to protect marine organisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Content Heavy Metal Pb, Cd In Perna viridis And Sediments In Semarang Bay

    Science.gov (United States)

    Suprapto, D.; Suryanti, S.; Latifah, N.

    2018-02-01

    Waste disposal from human activities, generally contain heavy metals such as Pb and Cd which derived from industrial activities. The aims of the study were to know the concentration of Pb and Cd heavy metals contained in Perna viridis tissue, sediment and water at Semarang Bay. This study was conducted in May 2017 at Semarang Bay. - Samples were collected using purposive sampling method. The heavy metal content in the water and clam was observed using- APHA method and was analyzed using AAS (Atomic Absorption Spectrophotometer). The results showed that concentration of heavy metal of Pb in the water was 0.00-50.5mg/L and the Cd content was of 26.9-51.7 mg/L, whereas the concentration of Pb in the sediment is 445.5-2.053.0mg/L and Cd 963.3-2,150.0 mg/L. Pb content in soft tissue of Perna viridis - is 67.1-1.933.9 mg/L and the concentration of Cd was 203.5-5.787.3 mg/L. The analysis of Pb and Cd in seawater, sediment and soft tissue of Perna viridis according to Enviroment Ministerial decree (KepMenLH ) number 51 of 2004 and applied by NOAA 1999 does not exceed the quality standard, that meant that the Perna viridis has been contaminated by metal Pb it is controversial with the above sentence and Cd. It concluded that the metal content of Pb and Cd in Perna viridis tissue exceeds the quality standard, so it is not suitable to be consumed, especially in high quantity

  17. Sediment Retention Dynamics and Vegetation Along Three Tributaries of the Chesapeake Bay

    Science.gov (United States)

    Ross, K.; Ross, K.; Hupp, C.; Alexander, L.; Alexander, L.

    2001-12-01

    Coastal Plain riparian wetlands in the Mid-Atlantic United States are the last place for sediment and contaminant storage before reaching critical estuarine and marine environments. The deteriorating health of the Chesapeake Bay has been attributed in part to elevated sediment loads. The purpose of this study is to investigate the effects of channelization and urbanization on sediment deposition and geomorphic processes along the Pocomoke and Chickahominy Rivers and Dragon Run, three Coastal Plain tributaries. Floodplain microtopography was surveyed in 100 x 100 m grids at three characteristic reaches along each river and woody vegetation analyses were conducted. Floodplain suspended sediment concentrations and short and long-term sedimentation rates were estimated at each reach using single stage sediment sampler arrays, clay pads and dendrogeomorphic techniques, respectively. Site hydroperiod and flow characteristics were determined from USGS gaging station records, floodplain water level recorders, and field observations. Channelized floodplain reaches along the Pocomoke River are flooded less frequently, have lower mineral sedimentation rates (2 mm/yr to 6 mm/yr) and woody species diversity than the unchannelized reaches. Along the Chickahominy River, floodplain wetlands close to urban centers are flooded more frequently, but have shorter hydroperiods (3.5 days/yr compared to more than 45 days/yr), lower sedimentation rates (1.8 mm/yr to 6.8 mm/yr), and lower woody species diversity (0.51 to 1.95 on the Shannon-Weiner diversity index) than floodplains further downstream. Suspended sediment delivery and deposition rates are significantly influenced by floodplain hydroperiod duration and channel-floodplain connectivity. These results suggest that understanding floodplain sediment dynamics and geomorphic processes with respect to dominant watershed landuse patterns is critical for effective water quality management and restoration efforts.

  18. 226Ra and 228Ra in the mixing zones of the Pee Dee River-Winyah Bay, Yangtze River and Delaware Bay Estuaries

    International Nuclear Information System (INIS)

    Elsinger, R.J.; Moore, W.S.

    1984-01-01

    226 Ra and 228 Ra have non-conservative excess concentrations in the mixing zones of the Pee Dee River-Winyah Bay estuary, the Yangtze River estuary, and the Delaware Bay estuary. Laboratory experiments, using Pee Dee River sediment, indicate desorption of 226 Ra to increase with increasing salinities up to 20 per mille. In Winyah Bay desorption from river-borne sediments could contribute almost all of the increases for both isotopes. Desorption adds only a portion of the excess 228 Ra measured in the Yangtze River and adjacent Shelf waters and Delaware Bay. In the Yangtze River the mixing zone extends over a considerable portion of the Continental Shelf where 228 Ra is added to the water column by diffusion from bottom sediments, while 226 Ra concentrations decrease from dilution. Diffusion of 228 Ra from bottom sediments in Delaware Bay primarily occurs in the upper part of the bay ( 228 Ra of 0.33 dpm cm -2 year was determined for Delaware Bay. (author)

  19. Speciation of heavy metals in different grain sizes of Jiaozhou Bay sediments: Bioavailability, ecological risk assessment and source analysis on a centennial timescale.

    Science.gov (United States)

    Kang, Xuming; Song, Jinming; Yuan, Huamao; Duan, Liqin; Li, Xuegang; Li, Ning; Liang, Xianmeng; Qu, Baoxiao

    2017-09-01

    Heavy metal contamination is an essential indicator of environmental health. In this work, one sediment core was used for the analysis of the speciation of heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in Jiaozhou Bay sediments with different grain sizes. The bioavailability, sources and ecological risk of heavy metals were also assessed on a centennial timescale. Heavy metals were enriched in grain sizes of Pb > Cd > Zn > Cu >Ni > Cr > As. Enrichment factors (EF) indicated that heavy metals in Jiaozhou Bay presented from no enrichment to minor enrichment. The potential ecological risk index (RI) indicated that Jiaozhou Bay had been suffering from a low ecological risk and presented an increasing trend since 1940s owing to the increase of anthropogenic activities. The source analysis indicated that natural sources were primary sources of heavy metals in Jiaozhou Bay and anthropogenic sources of heavy metals presented an increasing trend since 1940s. The principal component analysis (PCA) indicated that Cr, Mn, Ni, Cu and Pb were primarily derived from natural sources and that Zn and Cd were influenced by shipbuilding industry. Mn, Cu, Zn and Pb may originate from both natural and anthropogenic sources. As may be influenced by agricultural activities. Moreover, heavy metals in sediments of Jiaozhou Bay were clearly influenced by atmospheric deposition and river input. Copyright © 2017. Published by Elsevier Inc.

  20. Comparison of test specific sediment effect concentrations with marine sediment quality assessment guidelines

    International Nuclear Information System (INIS)

    Carr, R.S.; Biedenbach, J.M.; MacDonald, D.D.

    1995-01-01

    As part of NOAA's National Status and Trends (NS and T) Bioeffects Assessment program and studies conducted by the National Biological Service, numerous sediment quality assessment surveys have recently been conducted along the Atlantic and Gulf coasts of the US using the sea urchin (Arbacia punctulata) fertilization and embryological development tests with pore water. Additional toxicity tests were also conducted in conjunction with most of these studies. The areas that have been sampled include Boston harbor, Massachusetts; Charleston Harbor, Winyah Bay, and Savannah River, South Carolina; St. Simon Sound, Georgia; Biscayne Bay, Tampa Bay, Choctawhatchee Bay, Apalachicola Bay, St. Andrew Bay, and Pensacola Bay, Florida; Galveston Bay, Lavaca Bay, and Sabine Lake, Texas, and 200 stations in the vicinity of offshore oil and gas production platforms in the Gulf of Mexico. Sufficient data are now available from this series of surveys to calculate test specific sediment effect concentrations (SECs). Based on these recent studies, SECs were developed for the sea urchin porewater and amphipod tests and compared with existing marine sediment quality assessment guidelines

  1. Multi-elemental analysis of marine sediments of Sorsogon Bay using x-ray fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Gonzales, Ralph Roly A.; Quirit, Leni L.; Rosales, Colleen Marciel F.; Pabroa, Preciosa Corazon B.; Sta Maria, Efren J.

    2011-01-01

    Metal composition and nutrient loadings of our bodies of water, when uncontrolled, may cause harmful bacterial contamination and pose threats in aquatic and human life. Toxic and trace element inputs in Sorsogon Bay sediments were determined using nuclear analytical techniques, more specifically, x-ray fluorescence spectrometry, in this study. Pre-treated marine sediment samples from Sorsogon Bay were homogenized using SPEX # 8000 mixer/mill and agate mortar and pestle, pelletized into 31-mm flat discs using SPEX 3630 X-Press and analyzed using PAN Analytical Epsilon 5 EDX X-ray Fluorescence Spectrometer with the emission and transmission method using silver and germanium secondary targets. Spectrum fitting performed using AXIL (Analysis of X-ray Spectra by Iterative Least-Squares Fitting), a subprogram in Quantitative X-ray Analysis System developed by the International Atomic Energy Agency and Quantitative Analysis of Environmental Samples program, was used for quantification of results. Results indicate generally moderate to high metal enrichment, specifically manganese, lead, cadmium, zinc and copper. Mercury and iron level enrichment are found to be low, marking an improvement from previous studies indicating high enrichment of these metals. (author)

  2. Diffusion of Nitrogen and Phosphorus Across the Sediment-Water Interface and In Seawater at Aquaculture Areas of Daya Bay, China

    Directory of Open Access Journals (Sweden)

    Xiangju Cheng

    2014-01-01

    Full Text Available With the yearly increasing marine culture activities in floating cages in Daya Bay, China, the effects of pollution may overlap and lead to more severe water environmental problems. In order to track the impacts of the marine culture in floating cages on water environment, sediments and overlying water were sampled by cylindrical samplers at three representative aquaculture areas of Daya Bay. The water content, porosity, density of sediments as well as the vertical distributions of ammonia nitrogen and active phosphate in pore water along sediments depth were measured. The release rate and annual released quantity of the nutrients across sediment-water interface were calculated using Fick’s Law. A horizontal two-dimensional mathematical model was developed to compute the spatial and temporal distributions of the nutrients in seawater after being released across the sediment-water interface. The results showed that the sediments, with a high content and a large annual released quantity of nitrogen and phosphorus, constitute a potential inner source of seawater pollution. Influenced by tide and water depth, the scope of diffusion and migration of the nutrients appears as a long belt which is about 1 km long and 50 m wide. Seawater in this area is vulnerable to eutrophication.

  3. Sediment Sampling for Poly-Aromatic Hydrocarbons (PAHs) in Mobile Bay and Mississippi Sound in 2013 (NODC Accession 0116480)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sediment samples were collected at ten sites within Mobile Bay and Mississippi Sound on January 28, 2013, for PAH analysis. All samples tested were below detection...

  4. Effects of ghost shrimp on zinc and cadmium in sediments from Tampa Bay, FL

    Science.gov (United States)

    Klerks, P.L.; Felder, D.L.; Strasser, K.; Swarzenski, P.W.

    2007-01-01

    This study investigated the effects that ghost shrimp have on the distribution of metals in sediment. We measured levels of HNO3-extractable zinc and cadmium in surface sediment, in ghost shrimp burrow walls and in sediment ejected by the ghost shrimp from their burrows, at five sandy intertidal sites in Tampa Bay. Ghost shrimp densities and their rate of sediment ejection were also quantified, as were sediment organic content and silt + clay content. Densities of ghost shrimp (Sergio trilobata and Lepidophthalmus louisianensis) averaged 33/m2 at our sites, and they ejected sediment at an average rate of 28 g/burrow/day. Levels of both Zn and Cd were significantly higher in burrow walls than in surface sediments. Sediment ejected by the shrimp from their burrows had elevated levels of Zn (relative to surface sediments) at one of the sites. Sediment organic content and silt + clay content were higher in burrow-wall sediments than in ejected sediment, which in turn tended to have values above those of surface sediments. Differences in levels of HNO3-extractable Zn and Cd among sediment types may be a consequence of these sediments differing in other physiochemical characteristics, though the differences in metal levels remained statistically significant for some sites after correcting for differences in organic content and silt + clay content. We conclude that the presence of ghost shrimp burrows contributes to spatial heterogeneity of sedimentary metal levels, while the ghost shrimp bioturbation results in a significant flux of metals to the sediment surface and is expected to decrease heterogeneity of metal levels in sedimentary depth profiles.

  5. 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

  6. Long-Term Changes in Sediment and Nutrient Delivery from Conowingo Dam to Chesapeake Bay: Effects of Reservoir Sedimentation.

    Science.gov (United States)

    Zhang, Qian; Hirsch, Robert M; Ball, William P

    2016-02-16

    Reduction of suspended sediment (SS), total phosphorus (TP), and total nitrogen is an important focus for Chesapeake Bay watershed management. The Susquehanna River, the bay's largest tributary, has drawn attention because SS loads from behind Conowingo Dam (near the river's mouth) have been rising dramatically. To better understand these changes, we evaluated histories of concentration and loading (1986-2013) using data from sites above and below Conowingo Reservoir. First, observed concentration-discharge relationships show that SS and TP concentrations at the reservoir inlet have declined under most discharges in recent decades, but without corresponding declines at the outlet, implying recently diminished reservoir trapping. Second, best estimates of mass balance suggest decreasing net deposition of SS and TP in recent decades over a wide range of discharges, with cumulative mass generally dominated by the 75∼99.5th percentile of daily Conowingo discharges. Finally, stationary models that better accommodate effects of riverflow variability also support the conclusion of diminished trapping of SS and TP under a range of discharges that includes those well below the literature-reported scour threshold. Overall, these findings suggest that decreased net deposition of SS and TP has occurred at subscour levels of discharge, which has significant implications for the Chesapeake Bay ecosystem.

  7. Radionuclides in intertidal sands and sediments from Morecambe Bay to the Dee estuary

    International Nuclear Information System (INIS)

    Carpenter, R.C.; Burton, P.J.; Strange, L.P.; Pratley, F.W.

    1991-05-01

    Surface and core samples of intertidal sediments have been collected from the coastline from Morecambe Bay to the Dee Estuary. The sampling took place between October 1987 and July 1989. Caesium-137 was determined by high resolution gamma spectrometry and plutonium isotopes and americium-241 were determined by alpha spectrometry following radiochemical separations. Samples were also sieved to obtain a particle size distribution of the deposits. A wide range of radionuclide activities have been determined depending on the distance from Sellafield and, more importantly, the proportion of clay plus silt ( 239+240 Pu and 241 Am activity discharged by Sellafield up to the end of 1988. The measured activities generally represent a small fraction of the Generalised Derived Limits (GDL's) for marine sediments. (author)

  8. The onset of deglaciation of Cumberland Bay and Stromness Bay, South Georgia

    NARCIS (Netherlands)

    Van Der Putten, N.; Verbruggen, C.

    Carbon dating of basal peat deposits in Cumberland Bay and Stromness Bay and sediments from a lake in Stromness Bay, South Georgia indicates deglaciation at the very beginning of the Holocene before c. 9500 14C yr BP. This post-dates the deglaciation of one local lake which has been ice-free since

  9. Integrated assessment of mangrove sediments in the Camamu Bay (Bahia, Brazil).

    Science.gov (United States)

    Paixão, Joana F; de Oliveira, Olívia M C; Dominguez, José M L; Almeida, Edna dos Santos; Carvalho, Gilson Correia; Magalhães, Wagner F

    2011-03-01

    Camamu Bay, an Environmentally Protected Area, may be affected by the pressures of tourism and oil exploration in the adjacent continental platform. The current quality of the mangrove sediments was evaluated by porewater bioassays using embryos of Crassostrea rhizophorae and by an analysis of benthic macrofauna and its relationships with organic compounds, trace metals and bioavailability. Porewater toxicity varied from low to moderate in the majority of the samples, and polychaetes dominated the benthos. The Grande Island sampling station (Station 1) presented more sandy sediments, differentiated macrobenthic assemblages and the highest metal concentrations in relation to other stations and guideline values, and it was the only station that indicated a possible bioavailability of metals. The origin of the metals (mainly barium) is most likely associated with the barite ore deposits located in the Grande and Pequena islands. These results may be useful for future assessment of the impact of oil exploration in the coastal region. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Nutrient fluxes across sediment-water interface in Bohai Bay Coastal Zone, China.

    Science.gov (United States)

    Mu, Di; Yuan, Dekui; Feng, Huan; Xing, Fangwei; Teo, Fang Yenn; Li, Shuangzhao

    2017-01-30

    Sediment cores and overlying water samples were collected at four sites in Tianjin Coastal Zone, Bohai Bay, to investigate nutrient (N, P and Si) exchanges across the sediment-water interface. The exchange fluxes of each nutrient species were estimated based on the porewater profiles and laboratory incubation experiments. The results showed significant differences between the two methods, which implied that molecular diffusion alone was not the dominant process controlling nutrient exchanges at these sites. The impacts of redox conditions and bioturbation on the nutrient fluxes were confirmed by the laboratory incubation experiments. The results from this study showed that the nutrient fluxes measured directly from the incubation experiment were more reliable than that predicted from the porewater profiles. The possible impacts causing variations in the nutrient fluxes include sewage discharge and land reclamation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Petroleum pollution in surface sediments of Daya Bay, South China, revealed by chemical fingerprinting of aliphatic and alicyclic hydrocarbons

    Science.gov (United States)

    Gao, Xuelu; Chen, Shaoyong

    2008-10-01

    Nine surface sediments collected from Daya Bay have been Soxhlet-extracted with 2:1 (v/v) dichloromethane-methanol. The non-aromatic hydrocarbon (NAH) fraction of solvent extractable organic matter (EOM) and some bulk geochemical parameters have been analyzed to determine petroleum pollution of the bay. The NAH content varies from 32 to 276 μg g -1 (average 104 μg g -1) dry sediment and accounts for 5.8-64.1% (average 41.6%) of the EOM. n-Alkanes with carbon number ranging from 15 to 35 are identified to be derived from both biogenic and petrogenic sources in varying proportions. The contribution of marine authigenic input to the sedimentary n-alkanes is lower than the allochthonous input based on the average n-C 31/ n-C 19 alkane ratio. 25.6-46.5% of the n-alkanes, with a mean of 35.6%, are contributed by vascular plant wax. Results of unresolved complex mixture, isoprenoid hydrocarbons, hopanes and steranes also suggest possible petroleum contamination. There is strong evidence of a common petroleum contamination source in the bay.

  12. 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

  13. Sediment Quality of the SW Coastal Laizhou Bay, Bohai Sea, China: A Comprehensive Assessment Based on the Analysis of Heavy Metals

    Science.gov (United States)

    Gao, Xuelu; Zhuang, Wen; Chen, Chen-Tung Arthur; Zhang, Yong

    2015-01-01

    Historically, the Bohai Sea is one of the most important fishing grounds in China. Yet, surrounded by one of the biggest economic rims of China, its ecological functions have been declining rapidly in recent two decades under the heavy anthropogenic impacts. The Laizhou Bay is the smallest one of the three main bays in the Bohai Sea. Owing to the rich brine deposits, chemical industries using brine as raw materials are booming in the southern coast of the Laizhou Bay, the scale of which ranks as the largest one in China. In order to monitor and assess the environmental quality, surface sediments were collected from the coastal waters of southwestern Laizhou Bay and the rivers it connects with during summer and autumn in 2012, and analyzed for heavy metals. Several widely adopted methods were used in the overall assessment of heavy metal pollution status and potential ecological risks in these sediments, and the data were analyzed to infer the main sources of the pollutants. The results showed that the remarkably high concentrations of heavy metals were almost all recorded in a small number of riverine sites. Cr, Cu, Ni and Zn were the main environmental threat according to the sediment quality guidelines. The marine area was generally in good condition with no or low risk from the studied metals and adverse effects on biota could hardly occur. Natural sources dominated the concentrations and distributions of Cu, Ni, Pb and Zn in the marine area. Our results indicated that heavy metal pollution was not a main cause of the ecological degradation of the Laizhou Bay at present. PMID:25816338

  14. Sediment quality of the SW coastal Laizhou Bay, Bohai Sea, China: a comprehensive assessment based on the analysis of heavy metals.

    Science.gov (United States)

    Gao, Xuelu; Zhuang, Wen; Chen, Chen-Tung Arthur; Zhang, Yong

    2015-01-01

    Historically, the Bohai Sea is one of the most important fishing grounds in China. Yet, surrounded by one of the biggest economic rims of China, its ecological functions have been declining rapidly in recent two decades under the heavy anthropogenic impacts. The Laizhou Bay is the smallest one of the three main bays in the Bohai Sea. Owing to the rich brine deposits, chemical industries using brine as raw materials are booming in the southern coast of the Laizhou Bay, the scale of which ranks as the largest one in China. In order to monitor and assess the environmental quality, surface sediments were collected from the coastal waters of southwestern Laizhou Bay and the rivers it connects with during summer and autumn in 2012, and analyzed for heavy metals. Several widely adopted methods were used in the overall assessment of heavy metal pollution status and potential ecological risks in these sediments, and the data were analyzed to infer the main sources of the pollutants. The results showed that the remarkably high concentrations of heavy metals were almost all recorded in a small number of riverine sites. Cr, Cu, Ni and Zn were the main environmental threat according to the sediment quality guidelines. The marine area was generally in good condition with no or low risk from the studied metals and adverse effects on biota could hardly occur. Natural sources dominated the concentrations and distributions of Cu, Ni, Pb and Zn in the marine area. Our results indicated that heavy metal pollution was not a main cause of the ecological degradation of the Laizhou Bay at present.

  15. Sediment quality of the SW coastal Laizhou Bay, Bohai Sea, China: a comprehensive assessment based on the analysis of heavy metals.

    Directory of Open Access Journals (Sweden)

    Xuelu Gao

    Full Text Available Historically, the Bohai Sea is one of the most important fishing grounds in China. Yet, surrounded by one of the biggest economic rims of China, its ecological functions have been declining rapidly in recent two decades under the heavy anthropogenic impacts. The Laizhou Bay is the smallest one of the three main bays in the Bohai Sea. Owing to the rich brine deposits, chemical industries using brine as raw materials are booming in the southern coast of the Laizhou Bay, the scale of which ranks as the largest one in China. In order to monitor and assess the environmental quality, surface sediments were collected from the coastal waters of southwestern Laizhou Bay and the rivers it connects with during summer and autumn in 2012, and analyzed for heavy metals. Several widely adopted methods were used in the overall assessment of heavy metal pollution status and potential ecological risks in these sediments, and the data were analyzed to infer the main sources of the pollutants. The results showed that the remarkably high concentrations of heavy metals were almost all recorded in a small number of riverine sites. Cr, Cu, Ni and Zn were the main environmental threat according to the sediment quality guidelines. The marine area was generally in good condition with no or low risk from the studied metals and adverse effects on biota could hardly occur. Natural sources dominated the concentrations and distributions of Cu, Ni, Pb and Zn in the marine area. Our results indicated that heavy metal pollution was not a main cause of the ecological degradation of the Laizhou Bay at present.

  16. Natural and Anthropogenic Causes of Accelerated Sediment Accumulation Rates in Nehalem Bay Salt Marshes, Oregon

    Science.gov (United States)

    Molino, G. D.; Wheatcroft, R. A.; Peck, E. K.; Brophy, L.

    2016-12-01

    Vertical sediment accretion in estuarine salt marshes occurs as sediments settle out of the water column and onto marsh soils during periods of tidal inundation - thus accretion is influenced by both relative sea level rise (RSLR) and sediment flux to the estuary. Oregon estuaries are understudied compared to their East and Gulf Coast counterparts, but provide a unique opportunity to disentangle these effects. A broader study in three Oregon estuaries (Peck et al., this session) indicates RSLR as the dominant factor controlling sedimentation rates. Working in Nehalem Bay (northern Oregon coast), replicate sediment cores were taken along several transects across an elevation gradient for analysis of sediment and carbon accumulation using CT scans, gamma detection of Pb-210, X-Ray Fluorescence (XRF) and Loss-on-Ignition (LOI). Preliminary results indicate sediment accumulation rates over the past century are higher than rates seen in other comparable Oregon salt marshes; this is consistent with past studies and preliminary analysis of remote sensing data that show significant horizontal expansion of Nehalem marshes. A number of possible causes for the high sediment accumulation rates - hydroclimate of Nehalem River, extensive timber harvesting, forest fires such as the so-called Tillamook Burns, and diking of adjacent marshes - are being explored.

  17. Plutonium isotopes, ''2''4''1Am and ''1''3''7Cs activity concentrations in marine sediments of Gokova Bay agean Turkish coast

    International Nuclear Information System (INIS)

    Ugur Tanbay, A.; Yener, G.

    2001-01-01

    Samples of marine surface sediments of different grain sizes collected in Goekova , a small bay on the Aegean Turkish Coast, have been examined to measure α- and γ- radioactivity. The purpose of this research is to define a baseline study of man-made radionuclides on sediments collected along Goekova Bay, using a combination of direct gamma spectrometry, radiochemical separation and a-spectrometry. As the artificial radionuclides, ''1''3''7Cs for all sediment cores samples were under detection limit. The activity concentrations of the ''2''3''9'',''2''4''0Pu were observed to be in the range of 0.13±0.017-0.85±0.15Bq.kg''-''1. ''2''4''1Am and ''2''3''8Pu were identified at a very low level

  18. Physical processes in a coupled bay-estuary coastal system: Whitsand Bay and Plymouth Sound

    Science.gov (United States)

    Uncles, R. J.; Stephens, J. A.; Harris, C.

    2015-09-01

    Whitsand Bay and Plymouth Sound are located in the southwest of England. The Bay and Sound are separated by the ∼2-3 km-wide Rame Peninsula and connected by ∼10-20 m-deep English Channel waters. Results are presented from measurements of waves and currents, drogue tracking, surveys of salinity, temperature and turbidity during stratified and unstratified conditions, and bed sediment surveys. 2D and 3D hydrodynamic models are used to explore the generation of tidally- and wind-driven residual currents, flow separation and the formation of the Rame eddy, and the coupling between the Bay and the Sound. Tidal currents flow around the Rame Peninsula from the Sound to the Bay between approximately 3 h before to 2 h after low water and form a transport path between them that conveys lower salinity, higher turbidity waters from the Sound to the Bay. These waters are then transported into the Bay as part of the Bay-mouth limb of the Rame eddy and subsequently conveyed to the near-shore, east-going limb and re-circulated back towards Rame Head. The Simpson-Hunter stratification parameter indicates that much of the Sound and Bay are likely to stratify thermally during summer months. Temperature stratification in both is pronounced during summer and is largely determined by coastal, deeper-water stratification offshore. Small tidal stresses in the Bay are unable to move bed sediment of the observed sizes. However, the Bay and Sound are subjected to large waves that are capable of driving a substantial bed-load sediment transport. Measurements show relatively low levels of turbidity, but these respond rapidly to, and have a strong correlation with, wave height.

  19. Temporal trends and bioavailability assessment of heavy metals in the sediments of Deception Bay, Queensland, Australia.

    Science.gov (United States)

    Brady, James P; Ayoko, Godwin A; Martens, Wayde N; Goonetilleke, Ashantha

    2014-12-15

    Thirteen sites in Deception Bay, Queensland, Australia were sampled three times over a period of 7 months and assessed for contamination by a range of heavy metals, primarily As, Cd, Cr, Cu, Pb and Hg. Fraction analysis, enrichment factors and Principal Components Analysis-Absolute Principal Component Scores (PCA-APCS) analysis were conducted in order to identify the potential bioavailability of these elements of concern and their sources. Hg and Te were identified as the elements of highest enrichment in Deception Bay while marine sediments, shipping and antifouling agents were identified as the sources of the Weak Acid Extractable Metals (WE-M), with antifouling agents showing long residence time for mercury contamination. This has significant implications for the future of monitoring and regulation of heavy metal contamination within Deception Bay. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Sediment Dwelling Benthos as Indicator Species for Pollution Monitoring of Mamala Bay, Oahu, Hawaii, 1993-1994 (NODC Accession 9900121)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A multifaceted study of the sediment dwelling benthos was conducted in Mamala Bay to identify suitable species as indicators of sewage enrichment. There are five...

  1. Multi-elemental analysis of marine sediments of Manila Bay using x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Rosales, Colleen Marciel Fontelera

    2011-04-01

    An analysis of the marine sediments of Manila Bay was done by employing X-ray fluorescence spectrometry. The general trends observed in sediments are increasing (Ca and Sr), decreasing (Zr), or constant (Cl, Na, S, K) with respect to depth, sometimes, no trend can be observed. These trends are further explained by correlations present among these elements, plus all the other elements. The two X RF data analysis methods Auto Quantify and AXIL were also compared on the basis of the correlation plot obtained. AutoQuantify gave clearer correlations; thus, results from this method were used for constructing correlation plots. Correlations using Microsoft Excel and Stat graphics Centurion X V show that there are naturally occurring [lithogenic (Si, Ti, Al, Mg, Rb, Zn and Fe), biogenic (Ca, Mg), and conservative (Na, Cl)] and non-naturally occurring [mostly anthropogenic, brought to the bodies of water by aeolian or fluvial input (heavy metals Pb-Cu-Zn and Ni-Cr)] correlation present in the sediments. Moreover, pairs of elements that may coexist in a source and not coexist in another (Cr and Mg, Cr and Ni) have also been observed. The heavy metal enrichment was attributed to the burning of fossil fuels, iron and steel manufacturing (present in Valenzuela-Bulacan area), ferry and fishing services and other industrialization activities present in Manila Bay. Marine organisms are affected by the presence of these heavy metals by means of bioaccumulations, and may later on affect humans because of trophic transfer and bio magnification. (author)

  2. Seasonality of community structure and carbon flow in Narragansett Bay sediments

    International Nuclear Information System (INIS)

    Rudnick, D.T.

    1984-01-01

    Seasonal patterns of benthic community dynamics and the pathways of detrital decomposition in Narragansett Bay were examined. Benthic meiofauna and macrofauna exhibited a pronounced seasonality, with peak abundances in the late spring and minima in the late summer. This pattern was most pronounced for surface dwelling fauna, particularly harpacticoid copepods. These results were attributed to the seasonality of detrital inputs to the sediment and the fate of these inputs. A six month study in which 14 C-sodium bicarbonate was added to a large (13 m 3 ) microcosm enabled the author to observe pathways of carbon flow. Half of the labeled organic carbon that was deposited on the sediment during the winter and spring was found in the sediment in July. At least 20 gC/m 2 had accumulated since December. Within the sediment, the existence of two discrete food webs was distinguished by measurement of faunal specific activity. Surface fauna, dominated by the meiofauna, exclusively assimilate fresh (labeled) organics, while subsurface fauna (meiofauna and macrofauna) predominantly assimilated older, non-labeled organics for the duration of the study. Only the subsurface food web had access to the storage of buried detritus. While there was a surplus of detritus for both food webs during the winter and spring, the authors expect that benthic respiration rates exceed organic deposition rates during the summer. Detrital storage may be critical for the survival of the fauna through the summer

  3. Morphological changes within Florida Bay as a result of sea level rise

    Science.gov (United States)

    Holmes, C. W.

    2011-12-01

    Data from Florida Bay indicates that from 10,000 year BP to 6000 BP, the rate of sea level rise averaged about 10 mm/yr. The rate slowed at the end of this period flooding the shallow shelves surrounding the reef platforms of the western Atlantic. The relative flat South Florida shelf, because of its slight tilt to the southwest is an ideal local to assess the effects of this flooding. From 6000 BP to the present, numerous banks were formed within Florida Bay. A morphological model of bank formation based on the sea level oscillations was constructed from analysis of over 120 cores. These cores record sedimentological changes which are correlated to climatic events. In the central bay, the sediment accumulation was controlled by variations in rate of progressive sea-level rise. The Key West sea-level record shows that sea level has been rising incrementally over the last century. Between 1931 and 1950, sea level rose at a rate of 5 mm/yr. After 1950, it remained stable until 1971, when it again began to rise, but at a rate of 3 mm/yr. On the leeward side of mud banks, these variations resulted in shifts in sediment- accumulation rates, with accretion increasing during rising sea level and decreasing during stable periods. Between late 1970 and early 1972, a sharp jump in sea-level rise occurred that was approximately 10 cm higher than the preceding period. This jump coincided with a strongly positive North Atlantic Oscillation (NAO), a la Niña (negative ENSO), and a negative Pacific Decadal Oscillation (PDO). Water driven northward into Florida Bay eroded banks along the northern coastline, increased sediment accumulation in the northern lakes, and increased accretion rates on the banks. In addition to the sedimentological variations in the central portion of the bay, there was significant changes along the northern fringe. Around 1950, the northern fringe of the bay morphed from a fresh water environment to a marine environment. As a result, carbonate production

  4. Chemical and microbiological characterization of mangrove sediments after a large oil-spill in Guanabara Bay - RJ - Brazil

    OpenAIRE

    Maciel-Souza,Maria do Carmo; Macrae,Andrew; Volpon,Antonia Garcia Torres; Ferreira,Patrícia Silva; Mendonça-Hagler,Leda Cristina

    2006-01-01

    Seventeen months after a 1,3 million L oil spill into Guanabara Bay, analyses of mangrove sediments showed that the three sites closest to the spill remain highly polluted (>10 µg-g-1 polyaromatic hydrocarbons). A fourth site was less polluted, from which most hydrocarbon degrading bacteria were isolated.

  5. The impacts of land reclamation on suspended-sediment dynamics in Jiaozhou Bay, Qingdao, China

    Science.gov (United States)

    Gao, Guan Dong; Wang, Xiao Hua; Bao, Xian Wen; Song, Dehai; Lin, Xiao Pei; Qiao, Lu Lu

    2018-06-01

    A three-dimensional, high-resolution tidal model coupled with the UNSW sediment model (UNSW-Sed) based on Finite Volume Coastal Ocean Model (FVCOM) was set up to study the suspended-sediment dynamics and its change in Jiaozhou Bay (JZB) due to land reclamation over the period 1935 to 2008. During the past decades, a large amount of tidal flats were lost due to land reclamation. Other than modulating the tides, the tidal flats are a primary source for sediment resuspensions, leading to turbidity maxima nearshore. The tidal dynamics are dominant in controlling the suspended-sediment dynamics in JZB and have experienced significant changes with the loss of tidal flats due to the land reclamation. The sediment model coupled with the tide model was used to investigate the changes in suspended-sediment dynamics due to the land reclamation from 1935 to 2008, including suspended-sediment concentrations (SSC) and the horizontal suspended-sediment fluxes. This model can predict the general patterns of the spatial and temporal variation of SSC. The model was applied to investigate how the net transport of suspended sediments between JZB and its adjacent sea areas changed with land reclamation: in 1935 the net movement of suspended sediments was from JZB to the adjacent sea (erosion for JZB), primarily caused by horizontal advection associated with a horizontal gradient in the SSC; This seaward transport (erosion for JZB) had gradually declined from 1935 to 2008. If land reclamation on a large scale is continued in future, the net transport between JZB and the adjacent sea would turn landward and JZB would switch from erosion to siltation due to the impact of land reclamation on the horizontal advection of suspended sediments. We also evaluate the primary physical mechanisms including advection of suspended sediments, settling lag and tidal asymmetry, which control the suspended-sediment dynamics with the process of land reclamation.

  6. Alterations in the organic carbon pool recorded in sediments of Guanabara Bay, Brazil, a fertilized tropical estuary

    International Nuclear Information System (INIS)

    Carreira, R.S.; Kalas, F.A.; Santos, E.S.; Lima, A.L.; Godoy, J.M.; Wagener, A.L.R.

    1999-01-01

    We designed a core project in Guanabara Bay aimed at studying the possible anthropogenic impact on early diagenesis of sedimentary organic matter deposited in this system over the last century. The basic approach has been to look for the molecular, elemental (C, N and P) and isotopic compositions of organic matter in order to obtain the necessary information. The present work presents data on C, P and isotopic composition of organic matter, as well as the results of polyaromatic hydrocarbons, sedimentation rates and humic acids so far obtained for cores collected at several stations in the bay

  7. Subsoil erosion dominates the supply of fine sediment to rivers draining into Princess Charlotte Bay, Australia

    International Nuclear Information System (INIS)

    Olley, Jon; Brooks, Andrew; Spencer, John; Pietsch, Timothy; Borombovits, Daniel

    2013-01-01

    The Laura–Normanby River (catchment area: 24,350 km 2 ), which drains into Princess Charlotte Bay, has been identified in previous studies as the third largest contributor of sediment to the Great Barrier Reef World Heritage Area. These catchment scale modelling studies also identified surface soil erosion as supplying >80% of the sediment. Here we use activity concentrations of the fallout radionuclides 137 Cs and 210 Pb ex to test the hypothesis that surface soil erosion dominates the supply of fine ( 137 Cs and 210 Pb ex activity concentrations between samples collected using these two methods. Two methods were also used to collect samples to characterise 137 Cs and 210 Pb ex concentrations in sediment derived from surface soil erosion; sampling of surface-wash deposits and deployment of surface runoff traps that collected samples during rain events. While there was no difference in the 137 Cs activity concentrations for samples collected using these two methods, 210 Pb ex activity concentrations were significantly higher in the samples collected using the runoff traps. The higher 210 Pb ex concentrations are shown to be correlated with loss-on-ignition (r 2 = 0.79) and therefore are likely to be related to higher organic concentrations in the runoff trap samples. As a result of these differences we use a three end member mixing model (channel/gully, hillslope surface-wash and hillslope runoff traps) to determine the relative contribution from surface soil erosion. Probability distributions for 137 Cs and 210 Pb ex concentrations were determined for each of the end members, with these distributions then used to estimate the surface soil contribution to each of the collected river sediment samples. The mean estimate of contribution of surface derived sediment for all river samples (n = 70) is 16 ± 2%. This study reinforces the importance of testing model predictions before they are used to target investment in remedial action and adds to the body of evidence

  8. Concentration of Antifouling Biocides and Metals in Sediment Core Samples in the Northern Part of Hiroshima Bay

    Directory of Open Access Journals (Sweden)

    Noritaka Tsunemasa

    2014-06-01

    Full Text Available Accumulation of Ot alternative antifoulants in sediment is the focus of this research. Much research had been done on surface sediment, but in this report, the accumulation in the sediment core was studied. The Ot alternative antifoulants, Diuron, Sea-Nine211, and Irgarol 1051, and the latter’s degradation product, M1, were investigated in five samples from the northern part of Hiroshima Bay. Ot compounds (tributyltin (TBT and triphenyltin (TPT were also investigated for comparison. In addition, metal (Pb, Cu, Zn, Fe and Mn levels and chronology were measured to better understand what happens after accumulation on the sea floor. It was discovered that Ot alternative antifoulant accumulation characteristics in sediment were like Ot compounds, with the concentration in the sediment core being much higher than surface sediment. The concentration in sediment seems to have been affected by the regulation of Ot compounds in 1990, due to the concentration of Ot alternative antifoulants and Ot compounds at the survey point in front of the dock, showing an increase from almost the same layer after the regulation.

  9. Contamination of harbor sediments in the eastern Gulf of Finland (Neva Bay), Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Ussenkov, S.M. [Dept. of Lithology and Marine Geology, Faculty of Geology, St. Petersburg State Univ. (Russian Federation)

    1997-11-01

    The areal distribution of oil products and various trace metals have been studied in bottom surface deposits from the harbors of Neva Bay. The data of contents were normalized to natural background concentrations. Also the size and biomass of benthos groups were analyzed. The results show clearly that industrial discharges have elevated levels of contamination in the sediments. Few efficient measures against environmental contamination have been taken. The sediments contain very high concentrations of oil products and such heavy metals as Hg, Pb, Cu, and Zn. The benthic organisms most sensitive to heavy metal contamination are Chironomidae. The dredging and dumping of the contaminated deposits can lead to secondary contamination of the Gulf of Finland and the Baltic proper. (orig.)

  10. Submerged karst landforms observed by multibeam bathymetric survey in Nagura Bay, Ishigaki Island, southwestern Japan

    Science.gov (United States)

    Kan, Hironobu; Urata, Kensaku; Nagao, Masayuki; Hori, Nobuyuki; Fujita, Kazuhiko; Yokoyama, Yusuke; Nakashima, Yosuke; Ohashi, Tomoya; Goto, Kazuhisa; Suzuki, Atsushi

    2015-01-01

    Submerged tropical karst features were discovered in Nagura Bay on Ishigaki Island in the southern Ryukyu Islands, Japan. The coastal seafloor at depths shallower than ~ 130 m has been subjected to repeated and alternating subaerial erosion and sedimentation during periods of Quaternary sea-level lowstands. We conducted a broadband multibeam survey in the central area of Nagura Bay (1.85 × 2.7 km) and visualized the high-resolution bathymetric results over a depth range of 1.6-58.5 m. Various types of humid tropical karst landforms were found to coexist within the bay, including fluviokarst, doline karst, cockpit karst, polygonal karst, uvalas, and mega-dolines. Although these submerged karst landforms are covered by thick postglacial reef and reef sediments, their shapes and sizes are distinct from those associated with coral reef geomorphology. The submerged landscape of Nagura Bay likely formed during multiple glacial and interglacial periods. According to our bathymetric results and the aerial photographs of the coastal area, this submerged karst landscape appears to have developed throughout Nagura Bay (i.e., over an area of approximately 6 × 5 km) and represents the largest submerged karst in Japan.

  11. Paleogene Sediment Character of Mountain Front Central Sumatra Basin

    Directory of Open Access Journals (Sweden)

    P. A. Suandhi

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i3.164The SE-NW trending Mountain Front of Central Sumatra Basin is located in the southern part of the basin. The Mountain Front is elongated parallel to the Bukit Barisan Mountain, extending from the Regencies of North Padang Lawas (Gunung Tua in the northwest, Rokan Hulu, Kampar, Kuantan Singingi, and Inderagiri Hulu Regency in the southeast. The Palaeogene sediments also represent potential exploration objectives in Central Sumatra Basin, especially in the mountain front area. Limited detailed Palaeogene sedimentology information cause difficulties in hydrocarbon exploration in this area. Latest age information and attractive sediment characters based on recent geological fieldwork (by chaining method infer Palaeogene sediment potential of the area. The Palaeogene sedimentary rock of the mountain front is elongated from northwest to southeast. Thickness of the sedimentary unit varies between 240 - 900 m. Palynology samples collected recently indicate that the oldest sedimentary unit is Middle Eocene and the youngest one is Late Oligocene. This latest age information will certainly cause significant changes to the existing surface geological map of the mountain front area. Generally, the Palaeogene sediments of the mountain front area are syn-rift sediments. The lower part of the Palaeogene deposit consists of fluvial facies of alluvial fan and braided river facies sediments. The middle part consists of fluvial meandering facies, lacustrine delta facies, and turbidity lacustrine facies sediments. The upper part consists of fluvial braided facies and transitional marine facies sediments. Volcanism in the area is detected from the occurrence of volcanic material as lithic material and spotted bentonite layers in the middle part of the mountain front area. Late rifting phase is indicated by the presence of transitional marine facies in the upper part of the Palaeogene sediments.

  12. Pathways of carbon oxidation in continental margin sediments off central Chile

    DEFF Research Database (Denmark)

    Thamdrup, B; Canfield, Donald Eugene

    1996-01-01

    Rates and oxidative pathways of organic carbon mineralization were determined in sediments at six stations on the shelf and slope off Concepcion Bay at 36.5 degrees S. The depth distribution of C oxidation rates was determined to 10 cm from accumulation of dissolved inorganic C in 1-5-d incubations...... the shelf was rich in NO3- and depleted of O2. Sediments at the four shelf stations were covered by mats of filamentous bacteria of the genera Thioploca and Beggiatoa. Carbon oxidation rates at these sites were extremely high near the sediment surface (>3 micromol cm-3 d-1) and decreased exponentially...... C oxidation between 0 and 10 cm. Carbon oxidation through Fe reduction contributed a further 12-29% of the depth-integrated rate, while the remainder of C oxidation was through SO4(2-) reduction. The depth distribution of Fe reduction agreed well with the distribution of poorly crystalline Fe oxides...

  13. DDT Analysis of Wetland Sediments in Upper Escambia Bay, Florida

    Science.gov (United States)

    Hopko, M. N.; Wright, J.; Liebens, J.; Vaughan, P.

    2017-12-01

    Dichlorodiphenyltrichloroethane (DDT) was a commonly used pesticide from World War II through the 1960's. DDT is generally used to control mosquito populations and as an agricultural insecticide. The pesticide and its degradation products (DDD and DDE) can bioaccumulate within ecosystems having negative implications for animal and human health. Consequently, DDT usage was banned in the United States in 1973. In a contaminant study performed in Escambia Bay, Florida, in 2009, DDT was present in 25% of study sites, most of which were located in the upper bay wetlands. Concentrations were well above the Florida Department of Environmental Protection's (FDEP) Probable Effect Level (PEL) and ratios of DDT and its metabolites indicated a recent introduction to the system. A follow-up study performed in 2016 found no DDT, but did show DDE at several sites. The current study repeated sampling in May 2017 at sites from the 2009 and 2016 studies. Sediment samples were collected in triplicate using a ponar sampler and DDT, DDD and DDE were extracted using EPA methods 3540c and 3620c. Extracts were analyzed using a gas chromatograph with electron capture detection (GC-ECD) as per EPA method 8081c. Sediment was also analyzed for organic carbon and particle size using an elemental NC analyzer and a laser diffraction particle sizer. Results show the presence of breakdown products DDE and DDD at multiple sites, but no detectable levels of DDT at any site. Sampling sites with high levels of DDT contamination in 2009 show only breakdown products in both 2016 and 2017. Particle size has little influence on DDD or DDE concentrations but OC is a controlling factor as indicated for contaminated sites by Pearson correlations between OC and DDE and DDD of 0.82 and 0.92, respectively. The presence of only DDD and/or DDE in the 2016 and 2017 studies indicates that the parent, DDT, has not been re-introduced into the watershed since 2009 but is degrading in the environment.

  14. Hydrocarbons in the suspended matter and the bottom sediments in different regions of the Black Sea Russian sector

    Directory of Open Access Journals (Sweden)

    I. A. Nemirovskaya

    2017-08-01

    Full Text Available Content and composition of hydrocarbons (mainly the aliphatic ones in the suspended matter and the bottom sediments in the Gelendzhik Bay, the Big Sochi water area, the Feodosiya Bay and the Black Sea central part are defined and compared with the total organic carbon and chlorophyll a contents. It is shown that the aliphatic hydrocarbon concentrations exceeding the background ones are found only in the coastal zone. Advancing to the pelagic zone is accompanied by sharp decrease of their concentrations. Petroleum and pyrogenic hydrocarbons are mainly manifested in the polycyclic aromatic hydrocarbons composition. Influence of construction of the Olympic facilities upon distribution of hydrocarbons in the Big Sochi water area was of short duration, and already by 2015 the aliphatic hydrocarbons concentration decreased, on the average, up to 24 µg/l in the surface waters, and up to 18 µg/g – in the bottom sediments. Accumulation of hydrocarbons took place in bottom sediments, where their concentrations exceeded the background ones in terms of dry weight. In the Gelendzhik Bay, their content reached 252 μg/g, and in the composition of organic carbon (Corg > 1 %, which may indicate the contamination of sediments with oil products. In the Feodosiya Bay their part in the composition of Corg did not exceed 0.73 % and was 0.35 % on average. Natural alkanes dominated in the composition of aliphatic hydrocarbons. The bottom sediments are characterized by the predominance of odd high-molecular terrigenous alkanes. The content of polycyclic aromatic hydrocarbons in the studied sediments was rather low: up to 31 ng/g in the Gelendzhik Bay, up to 348 ng/g in the Feodosiya Bay. These concentrations according to the EPA classification are considered background, or minor petroleum hydrocarbons increase the level of aliphatic hydrocarbons in water and sediments, thus creating a modern hydrocarbon background.

  15. A novel approach for characterization of polycyclic aromatic hydrocarbon (PAH) pollution patterns in sediments from Guanabara Bay, Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    Christensen, Jan H.; Tomasi, Giorgio; Scofield, Arthur de Lemos; Meniconi, Maria de Fatima Guadalupe

    2010-01-01

    A novel multivariate method based on principal component analysis of pre-processed sections of chromatograms is used to characterize the complex PAH pollution patterns in sediments from Guanabara Bay, Brazil. Five distinct sources of 3- to 6-ring PAHs could be revealed. The harbour is the most contaminated site in the bay, its plume stretches in a South West to North East direction and the chemical profile indicates mainly pyrogenic sources mixed with a fraction of high-molecular-weight petrogenic PAHs. Rio Sao Joao de Meriti is the second largest source of PAHs, and introduces mainly a fraction of low-molecular-weight petrogenic PAHs from the western region of Rio de Janeiro. The sites close to the ruptured pipeline at the Duque de Caxias Refinery show a distinctive pollution pattern indicating a heavy petroleum fraction. The method also led to the identification of new potential indicator ratios also involving coeluting peaks (e.g., triphenylene and chrysene). - A novel multivariate method is used to characterize the complex PAH pollution patterns in sediments from Guanabara Bay, Brazil.

  16. Distribution and risk assessment of trace metals in sediments from Yangtze River estuary and Hangzhou Bay, China.

    Science.gov (United States)

    Li, Feipeng; Mao, Lingchen; Jia, Yubao; Gu, Zhujun; Shi, Weiling; Chen, Ling; Ye, Hua

    2018-01-01

    The Yangtze River estuary (YRE) and Hangzhou Bay (HZB) is of environmental significance because of the negative impact from industrial activities and rapid development of aquaculture on the south bank of HZB (SHZB) in recent years. This study investigated the distribution and risk assessments of trace metals (Cr, Cu, Zn, Hg, Pb, and Cd) accumulated in surface sediments by sampling in YRE, outer and south HZB. Copper and Zn concentration (avg. 35.4 and 98.7 mg kg -1 , respectively) in surface sediments were generally higher than the background suggesting a widespread of Cu and Zn in the coastal area of Yangtze River Delta. High concentrations of Cu (~ 42 mg kg -1 ), Zn (~ 111 mg kg -1 ), Cd (~ 0.27 mg kg -1 ), and Hg (~ 0.047 mg kg -1 ) were found in inner estuary of YRE and decreased offshore as a result of terrestrial input and dilution effect of total metal contents by "cleaner" sediments from the adjacent sea. In outer HZB, accumulation of terrestrial derived metal has taken place near the Zhoushan Islands. Increase in sediment metal concentration from the west (inner) to the east (outer) of SHZB gave rise to the input of fine-grained sediments contaminated with metals from outer bay. According the results from geoaccumulation index, nearly 75% of samples from YRE were moderately polluted (1.0 < I geo  < 2.0) by Cd. Cadmium and Hg contributed for 80~90% to the potential ecological risk index in the YRE and HZB, with ~ 72% sites in HZB under moderate risk (150 ≤ RI < 300) especially near Zhoushan Islands.

  17. Polychlorinated biphenyls (PCBs) in recreational marina sediments of San Diego Bay, southern California.

    Science.gov (United States)

    Neira, Carlos; Vales, Melissa; Mendoza, Guillermo; Hoh, Eunha; Levin, Lisa A

    2018-01-01

    Polychlorinated biphenyl (PCB) concentrations were determined in surface sediments from three recreational marinas in San Diego Bay, California. Total PCB concentrations ranged from 23 to 153, 31-294, and 151-1387ngg -1 for Shelter Island Yacht Basin (SIYB), Harbor Island West (HW) and Harbor Island East (HE), respectively. PCB concentrations were significantly higher in HE and PCB group composition differed relative to HW and SIYB, which were not significantly different from each other in concentration or group composition. In marina sediments there was a predominance (82-85%) of heavier molecular weight PCBs with homologous groups (6CL-7CL) comprising 59% of the total. In HE 75% of the sites exceeded the effect range median (ERM), and toxicity equivalence (TEQ dioxin-like PCBs) values were higher relative to those of HW and SIYB, suggesting a potential ecotoxicological risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. The impact of urban expansion and agricultural legacies on trace metal accumulation in fluvial and lacustrine sediments of the lower Chesapeake Bay basin, USA

    International Nuclear Information System (INIS)

    Coxon, T.M.; Odhiambo, B.K.; Giancarlo, L.C.

    2016-01-01

    The progressively declining ecological condition of the Chesapeake Bay is attributed to the influx of contaminants associated with sediment loads supplied by its largest tributaries. The continued urban expansion in the suburbs of Virginia cities, modern agricultural activities in the Shenandoah Valley, the anthropogenic and climate driven changes in fluvial system hydrodynamics and their potential associated impacts on trace metals enrichment in the bay's tributaries necessitate constant environmental monitoring of these important water bodies. Eight "2"1"0Pb and "1"3"7Cs dated sediment cores and seventy two sediment grab samples were used to analyze the spatial and temporal distributions of Al, Ca, Mg, Cr, Cd, As, Se, Pb, Cu, Zn, Mn, and Fe in the waterways of the Virginia portion of the Chesapeake Bay basin. The sediment cores for trace metal historical fluctuation analysis were obtained in lower fluvial-estuarine environments and reservoirs in the upper reaches of the basin. The trace metal profiles revealed high basal enrichment factors (EF) of between 0.05 and 40.24, which are interpreted to represent early nineteenth century agricultural activity and primary resource extraction. Surficial enrichment factors on both cores and surface grab samples ranged from 0.01 (Cu) to 1421 (Cd), with Pb, Cu, Zn, and Cd enrichments a plausible consequence of modern urban expansion and industrial development along major transportation corridors. Contemporary surficial enrichments of As, Se, and Cr also ranged between 0 and 137, with the higher values likely influenced by lithological and atmospheric sources. Pearson correlation analyses suggest mining and agricultural legacies, coupled with aerosol deposition, are responsible for high metal concentrations in western lakes and headwater reaches of fluvial systems, while metal accumulation in estuarine reaches of the major rivers can be attributed to urban effluence and the remobilization of legacy sediments. - Highlights:

  19. The impact of urban expansion and agricultural legacies on trace metal accumulation in fluvial and lacustrine sediments of the lower Chesapeake Bay basin, USA

    Energy Technology Data Exchange (ETDEWEB)

    Coxon, T.M. [Department of Earth and Environmental Sciences, University of Mary Washington, 1301 College Avenue Fredericksburg, Virginia 22401 (United States); Odhiambo, B.K., E-mail: bkisila@umw.edu [Department of Earth and Environmental Sciences, University of Mary Washington, 1301 College Avenue Fredericksburg, Virginia 22401 (United States); Giancarlo, L.C. [Department of Chemistry, University of Mary Washington, Fredericksburg, VA 22401 (United States)

    2016-10-15

    The progressively declining ecological condition of the Chesapeake Bay is attributed to the influx of contaminants associated with sediment loads supplied by its largest tributaries. The continued urban expansion in the suburbs of Virginia cities, modern agricultural activities in the Shenandoah Valley, the anthropogenic and climate driven changes in fluvial system hydrodynamics and their potential associated impacts on trace metals enrichment in the bay's tributaries necessitate constant environmental monitoring of these important water bodies. Eight {sup 210}Pb and {sup 137}Cs dated sediment cores and seventy two sediment grab samples were used to analyze the spatial and temporal distributions of Al, Ca, Mg, Cr, Cd, As, Se, Pb, Cu, Zn, Mn, and Fe in the waterways of the Virginia portion of the Chesapeake Bay basin. The sediment cores for trace metal historical fluctuation analysis were obtained in lower fluvial-estuarine environments and reservoirs in the upper reaches of the basin. The trace metal profiles revealed high basal enrichment factors (EF) of between 0.05 and 40.24, which are interpreted to represent early nineteenth century agricultural activity and primary resource extraction. Surficial enrichment factors on both cores and surface grab samples ranged from 0.01 (Cu) to 1421 (Cd), with Pb, Cu, Zn, and Cd enrichments a plausible consequence of modern urban expansion and industrial development along major transportation corridors. Contemporary surficial enrichments of As, Se, and Cr also ranged between 0 and 137, with the higher values likely influenced by lithological and atmospheric sources. Pearson correlation analyses suggest mining and agricultural legacies, coupled with aerosol deposition, are responsible for high metal concentrations in western lakes and headwater reaches of fluvial systems, while metal accumulation in estuarine reaches of the major rivers can be attributed to urban effluence and the remobilization of legacy sediments

  20. Amino acid biogeochemistry and bacterial contribution to sediment organic matter along the western margin of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, L; Garg, A.; Borole, D.V.

    .7 to 50.0 % of TN of the sediments of BOB. Keywords: Sediment, THAA, D-amino acids, Bacteria, Degradation, Peptidoglycan, Bay of Bengal *Corresponding author. Tel.: +91 832 245537 Fax: +91 832 2450602 E-mail address: loretaferns@gmail.com (L...) was used. D- and L-enantiomers of aspartic acid, glutamic acid, serine and alanine were separated and determined in the sample by high performance liquid chromatography (HPLC, Shimadzu model 1) using fluorescence detector (Ex: 330 nm, Em: 445 nm) after...

  1. Integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling for assessing the provenance of beach sand in the San Francisco Bay Coastal System

    Science.gov (United States)

    Barnard, Patrick L.; Foxgrover, Amy C.; Elias, Edwin P.L.; Erikson, Li H.; Hein, James R.; McGann, Mary; Mizell, Kira; Rosenbauer, Robert J.; Swarzenski, Peter W.; Takesue, Renee K.; Wong, Florence L.; Woodrow, Donald L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Over 150 million m3 of sand-sized sediment has disappeared from the central region of the San Francisco Bay Coastal System during the last half century. This enormous loss may reflect numerous anthropogenic influences, such as watershed damming, bay-fill development, aggregate mining, and dredging. The reduction in Bay sediment also appears to be linked to a reduction in sediment supply and recent widespread erosion of adjacent beaches, wetlands, and submarine environments. A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach-sized sand in the region, thereby identifying the activities and processes that directly limit supply to the outer coast. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, Bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., Foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry to robustly determine the provenance of beach-sized sand in the region.

  2. Concentrations and compositions of organochlorine contaminants in sediments, soils, crustaceans, fishes and birds collected from Lake Tai, Hangzhou Bay and Shanghai city region, China

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Haruhiko [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan)]. E-mail: nakata@sci.kumamoto-u.ac.jp; Hirakawa, Yuko [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kawazoe, Masahiro [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, (Japan); Nakabo, Tetsuji [Kyoto University Museum, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Arizono, Koji [Faculty of Environmental and Symbiotic Sciences, Kumamoto Prefectural University, 3-1-100 Tsukide, Kumamoto 862-8502 (Japan); Abe, Shin-Ichi [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kitano, Takeshi [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Shimada, Hideaki [Faculty of Education, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Watanabe, Izumi [Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchuu-city, Tokyo 183-8509 (Japan); Li Weihua [Shanghai Institute of Planned Parenthood Research, 2140 Xie Tu road, Shanghai 200032 (China); Ding Xucheng [Shanghai Institute of Planned Parenthood Research, 2140 Xie Tu road, Shanghai 200032 (China)

    2005-02-01

    Contamination by persistent organochlorines (OCs), such as DDTs, hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) were examined in sediments, soils, fishes, crustaceans, birds, and aquaculture feed from Lake Tai, Hangzhou Bay, and in the vicinity of Shanghai city in China during 2000 and 2001. OCs were detected in all samples analyzed, and DDT and its metabolites were the predominant contaminants in most sediments, soils and biota. Concentrations of p,p'-DDT and ratio of p,p'-DDT to {sigma}DDTs were significantly higher in marine fishes than those in freshwater fishes. While the use of DDTs has been officially banned in China since 1983, these results indicate a recent input of technical DDTs into the marine environment around Hangzhou Bay. Comparison of organochlorine concentrations in fishes collected from Lake Tai and Hangzhou Bay suggests the presence of local sources of HCHs, chlordanes and PCBs at Lake Tai. Higher proportions of penta- and hexa-PCB congeners in fishes at Lake Tai may suggest the use of highly chlorinated PCB product, such as PCB{sub 5}, around this lake. To our knowledge, this is a first comprehensive study to examine the present status of organochlorine contamination in various environmental media, such as sediments, soils and wildlife, in China. - Elevated concentrations of DDTs were detected in sediments, soils, and wildlife collected from China.

  3. Distribution of radionuclides in a marine sediment core off the waterspout of the nuclear power plants in Daya Bay, northeastern South China Sea.

    Science.gov (United States)

    Zhou, Peng; Li, Dongmei; Li, Haitao; Fang, Hongda; Huang, Chuguang; Zhang, Yusheng; Zhang, Hongbiao; Zhao, Li; Zhou, Junjie; Wang, Hua; Yang, Jie

    2015-07-01

    A sediment core was collected and dated using (210)Pbex dating method off the waterspout of nuclear power base of Daya Bay, northeastern South China Sea. The γ-emitting radionuclides were analyzed using HPGe γ spectrometry, gross alpha and beta radioactivity as well as other geochemical indicators were deliberated to assess the impact of nuclear power plants (NPP) operation and to study the past environment changes. It suggested that NPP provided no new radioactivity source to sediment based on the low specific activity of (137)Cs. Two broad peaks of TOC, TC and LOI accorded well with the commercial operations of Daya Bay NPP (1994.2 and 1994.5) and LNPP Phase I (2002.5 and 2003.3), implying that the mass input of cooling water from NPP may result into a substantial change in the ecological environment and Daya Bay has been severely impacted by human activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Biogeochemistry of sulfur and iron in Thioploca-colonized surface sediments in the upwelling area off central chile

    Science.gov (United States)

    Zopfi, Jakob; Böttcher, Michael E.; Jørgensen, Bo Barker

    2008-02-01

    The biogeochemistry of sedimentary sulfur was investigated on the continental shelf off central Chile at water depths between 24 and 88 m under partial influence of an oxygen minimum zone. Dissolved and solid iron and sulfur species, including the sulfur intermediates sulfite, thiosulfate, and elemental sulfur, were analyzed at high resolution in the top 20 cm. All stations were characterized by high rates of sulfate reduction, but only the sediments within the Bay of Concepción contained dissolved sulfide. Due to advection and/or in-situ reoxidation of sulfide, dissolved sulfate was close to bottom water values. Whereas the concentrations of sulfite and thiosulfate were mostly in the submicromolar range, elemental sulfur was by far the dominant sulfur intermediate. Although the large nitrate- and sulfur-storing bacteria Thioploca were abundant, the major part of S 0 was located extracellularly. The distribution of sulfur species and dissolved iron suggests the reaction of sulfide with FeOOH as an important pathway for sulfide oxidation and sulfur intermediate formation. This is in agreement with the sulfur isotope composition of co-existing elemental sulfur and iron monosulfides. In the Bay of Concepción, sulfur isotope data suggest that pyrite formation proceeds via the reaction of FeS with polysulfides or H 2S. At the shelf stations, on the other hand, pyrite was significantly depleted in 34S relative to its potential precursors FeS and S 0. Isotope mass balance considerations suggest further that pyritization at depth includes light sulfide, potentially originating from bacterial sulfur disproportionation. The δ 34S-values of pyrite down to -38‰ vs. V-CDT are among the lightest found in organic-rich marine sediments. Seasonal variations in the sulfur isotope composition of dissolved sulfate indicated a dynamic non-steady-state sulfur cycle in the surface sediments. The 18O content of porewater sulfate increased with depth at all sites compared to the

  5. Coupling between suboxic condition in sediments of the western Bay of Bengal and southwest monsoon intensification: A geochemical study

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N; Mir, I.A.; Parthiban, G.; Karapurkar, S.G.; Matta, V.M.; Naidu, P.D.; Naqvi, S.W.A.

    Reconstruction of paleo-redox conditions in a radiocarbon (14C) dated sediment core (SK-218/1), covering the past 45 ka (thousand calendar years), collected from the western Bay of Bengal (Lat: 14 degrees 02′N; Long: 82 degrees 00′E) at a water...

  6. Preliminary geotechnical properties of deepsea sediments from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    Geotechnical properties of the Plio-Pleistocene sediments from nodule bearing area in the Central Indian Basin have been studied to know shear strength and water content variation with depth. It reveals that surface sediments have low (less than 1 k...

  7. Recording of the Holocene sediment infilling in a confined tide-dominated estuary: the bay of Brest (Britanny, France)

    Science.gov (United States)

    Gregoire, Gwendoline; Le Roy, Pascal; Ehrhold, Axel; Jouet, Gwenael; Garlan, Thierry

    2016-04-01

    Modern estuaries constitute key areas for the preservation of sedimentary deposits related to the Holocene period. Several previous studies using stratigraphic reconstructions in such environments allowed to characterise the major parameters controlling the Holocene transgressive sequence and to decipher their respective role in the sedimentary infill: (1) the evolution of main hydrologic factors (wave or tide-dominated environment), (2) the sea level fluctuation and (3) the morphologies of the bedrock and the coastline. Nevertheless, the timing of the transgressive deposits and the detailed facies need to be precise in regard to the stratigraphic schemes. The Bay of Brest (Western Brittany, France) offers the opportunity to examine these points and to compare with previous studies. It constitutes an original tide-dominated estuary that communicates to the open sea (Iroise Sea) by a narrow strait. Two main rivers (Aulne and Elorn) are connected to a submerged paleovalleys network that was incised in the Paleozoic basement during lowstands and still preserved in the present morphology. It delineates the central basin surrounded by tidal flat located in sheltered area. The analysis of high and very-high resolution seismic lines recorded through the whole bay combined with sediment cores (up to 4.5 m long) and radiocarbon dating allow to precise the architecture and the timing of the thick Holocene coastal wedge. It is preserved from the valley network to the shore and presents a longitudinal variability (downstream-upstream evolution). The infill is divided into two successive stages (corresponding to the transgressive and highstand system tracts) which laterally evolve from the paleo-valley to the coast. Two units constitute the transgressive system tract. The oldest, dated from 8200 to 7000 cal B.P. is composed of fine-grained, organic-rich tidal flat deposits located in the sheltered area and organised in levees on the terrace bordering the paleo-valley. A tidal

  8. Distribution and Genetic Structure of Fucus distichus Linnaeus 1953 (formerly F. gardneri within Central San Francisco Bay

    Directory of Open Access Journals (Sweden)

    Stephen G. Whitaker

    2017-09-01

    Full Text Available doi: https://doi.org/10.15447/sfews.2017v15iss3art4Fucus distichus, a rockweed common to the mid-intertidal shoreline within the San Francisco Estuary (previously known as F. gardneri, was injured during the Cosco Busan oil spill in November 2007 and subsequent clean-up actions. Restoration planning activities are underway to help recover F. distichus at sites within central San Francisco Bay where damage occurred. As a first step, we conducted shoreline surveys during the summers of 2012–2013 to map the occurrence of this rockweed. Of the 151.73 km of rocky shoreline within the central bay, F. distichus covered 32.16 km of shoreline. The alga generally occurred in narrow bands but formed expansive beds at locations with natural, flat bedrock benches. We also observed F. distichus on artificial substrata such as seawalls and riprap, but not on pilings. Samples of F. distichus from 11 sites throughout the central / east San Francisco Bay were genetically analyzed (microsatellite genotyping. The populations analyzed (1 had low genetic diversity, (2 the frequency of homozygotes was higher than expected (suggesting high inbreeding, and (3 also displayed geographic population structure, in part driven by very small differences in the midst of extremely low within-population genetic diversity. However, these genetic data do not raise concerns for restoration methods in terms of choosing donor populations and mixing F. distichus from different sites within the central bay. The choice of donor populations should be based on practical criteria for effective restoration; individuals will nonetheless be taken from locations as nearby to donor sites as possible. Various locations throughout the central San Francisco Bay are composed of cobble or small riprap that are populated with F. distichus, which could provide efficient means of translocating rockweed for future restoration activities.

  9. Contaminant profiles for surface water, sediment, flora and fauna associated with the mangrove fringe along middle and lower East Tampa Bay

    Science.gov (United States)

    Contaminant concentrations are reported for surface water, sediment, seagrass, mangroves, Florida Crown conch, blue crabs and fish collected during 2010-2011 from the mangrove fringe along eastern Tampa Bay. Concentrations of trace metals, chlorinated pesticides, atrazine, total ...

  10. Accumulation patterns of lipophilic organic contaminants in surface sediments and in economic important mussel and fish species from Jakarta Bay, Indonesia

    International Nuclear Information System (INIS)

    Dwiyitno; Dsikowitzky, Larissa; Nordhaus, Inga; Andarwulan, Nuri; Irianto, Hari Eko; Lioe, Hanifah Nuryani; Ariyani, Farida; Kleinertz, Sonja

    2016-01-01

    Non-target screening analyses were conducted in order to identify a wide range of organic contaminants in sediment and animal tissue samples from Jakarta Bay. High concentrations of di-iso-propylnaphthalenes (DIPNs), linear alkylbenzenes (LABs) and polycyclic aromatic hydrocarbons (PAHs) were detected in all samples, whereas phenylmethoxynaphthalene (PMN), DDT and DDT metabolites (DDX) were detected at lower concentrations. In order to evaluate the uptake and accumulation by economic important mussel (Perna viridis) and fish species, contaminant patterns of DIPNs, LABs and PAHs in different compartments were compared. Different patterns of these contaminant groups were found in sediment and animal tissue samples, suggesting compound-specific accumulation and metabolism processes. Significantly higher concentrations of these three contaminant groups in mussel tissue as compared to fish tissue from Jakarta Bay were found. Because P. viridis is an important aquaculture species in Asia, this result is relevant for food safety. - Highlights: • Analyses of surface sediment and animal tissue samples from a tropical coastal system • Non-target screening enabled identification of a wide range of organic contaminants. • Comparison of contaminant patterns in surface sediments and animal tissue samples • Results illustrate compound-specific accumulation and metabolism processes. • Higher concentrations of all contaminants in mussel tissue as compared to fish tissue

  11. Distributions of nitrated polycyclic aromatic hydrocarbons in the sediment of Osaka Bay, Japan.

    Science.gov (United States)

    Uno, Seiichi; Tanaka, Hiroyuki; Kokushi, Emiko; Bacolod, Eugene T; Koyama, Jiro

    2017-11-30

    The distributions of 15 nitrated polycyclic aromatic hydrocarbons (NPAHs) in sediments collected at 44 sites throughout Osaka Bay, Japan were examined. The highest total NPAHs, with a concentration of 1949ng/kg dry weight, were detected near the city of Amagasaki. Some sites near the cities of Osaka, Kishiwada, sand Sakai registered ng/kg levels of NPAHs, but individual NPAH concentrations were relatively lower than those in previous studies. The sources were estimated using principal component analysis, and NPAHs were derived from exhaust gases of automobiles and industries at some sites. However, our results suggest that it is difficult to estimate the source, especially in coastal areas near big cities and large industrial areas, because the generation pathways between parent polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs are slightly different, and the ratio of PAHs and NPAHs could not be accurately reflect the characters of sources in sediments especially at coastal areas with large-scale industrial zones. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Sediment transport and development of banner banks and sandwaves in an extreme tidal system: Upper Bay of Fundy, Canada

    Science.gov (United States)

    Li, Michael Z.; Shaw, John; Todd, Brian J.; Kostylev, Vladimir E.; Wu, Yongsheng

    2014-07-01

    Multibeam sonar mapping and geophysical and geological groundtruth surveys were coupled with tidal current and sediment transport model calculations to investigate the sediment transport and formation processes of the complex seabed features off the Cape Split headland in the upper Bay of Fundy. The Cape Split banner bank, composed of coarse to very coarse sand, is a southwest-northeast oriented, large tear-drop shaped sand body with superimposed sand waves that show wavelengths from 15 to 525 m and heights from 0.5 to 19 m. Isolated and chains of barchan dunes occur on top of a shadow bank to the southeast of the banner bank. The barchan dunes are composed of well-sorted medium sand and are oriented northwest-southeast. Their mean height and width are 1.5 and 55 m, respectively. A gravel bank, with an elongated elliptical shape and west-east orientation, lies in the Minas Passage erosional trough east of the headland to form the counterpart to the sandy Cape Split banner bank. The southern face is featureless but the northern face is covered by gravel megaripples. Tidal model predictions and sediment transport calculations show that the formation of the banner bank and the gravel bank are due to the development of the transient counter-clockwise and clockwise tidal eddies respectively to the west and east of the headland. The formation of barchan dunes is controlled by the nearly unidirectional flow regime in outer Scots Bay. Sand waves on the flanks of the Cape Split banner bank show opposite asymmetry and the barchan dunes are asymmetric to the northeast. The tidal current and sediment transport predictions corroborate bedform asymmetry to show that sand wave migration and net sediment transport is to southwest on the northern flank of the banner bank but to northeast on the southern bank. Long-term migration of the Scots Bay barchan dunes is to the northeast. Spring-condition tidal currents can cause frequent mobilization and high-stage transport over the

  13. A field study of littoral processes in Estero Bay, California

    Science.gov (United States)

    Dingler, J.R.; Anima, R.J.; Molzan, D.E.; Luepke, Gretchen; Peterson, C.L.

    1982-01-01

    Estero Bay, which lies on the central California coast, has rocky headlands at both ends and sandy beaches within it. The shoreline of the bay has adjusted to be in equilibrium with the predominant wave climate, which is from the northwest. Because of its present shoreline configuration, the net southward littoral transport found along much of the California coast does not occur within Estero Bay. Instead, the sand primarily moves on- and offshore with a reversing longshore component. This sand transport pattern produces a littoral cell within Estero Bay even though there is no submarine canyon in the area. The primary sand sinks for this cell appear to be the sand spit south of Morro Rock and the entrance to Morro Bay itself, although this opinion was not experimentally verified. Field work during one summer (1978) and the following winter (1979) produced baseline data on the profile of and grain-size distribution across the littoral zone. In the offshore part of the littoral zone we also studied ripple size and type, internal structure, depth of erosion, and mineralogy. Although these data, which were collected along nine transects spaced 2 km apart, are inadequate to yield transport and energy rates, they indicate a northward decrease in wave energy within Estero Bay and a mixing of the sediments in the offshore. Box core and rod height data from grid points in seven meters of water showed that on the order of a meter of erosion occurred in the central part of the bay between the two sampling periods. Offshore, the data were incomplete, but at one station, in 17 m of water, at least 20 cm of erosion occurred.

  14. A Satellite Imagery Approach to Monitor Turbidity and Total Suspended Sediments in Green Bay, WI

    Science.gov (United States)

    Khazaei, B.; Hamidi, S.; Hosseiny, S. M. H.; Ekhtari, N.

    2017-12-01

    Fox River is a major source of land-based pollutants, nutrients, and sediment that flows into the southern Green Bay (GB). GB supplies one-third of the total nutrient loading to Lake Michigan. This can play a significant role in the biological functioning of the Bay and development of managerial scenarios. To name a few, it can degrade the quality of the aquatic life, add to the costs for treatment processes, and reduce coastal quality. Water quality evaluation is a time consuming and costly process. Spaceborne imagery data provides a cheap and valuable source of information as an alternative for field monitoring of the water resources. Sediment is an optically active variable; hence; remote sensing techniques can be utilized to estimate Total Suspended Sediments (TSS) and Turbidity (TU) of water. In this study, we developed relationships between remote sensing imagery data with daily in situ measurements of TSS and TU in the summers of 2011 to 2014. Surface reflectance (SR) values obtained from Band 1 of MYD09GQ dataset-a level 2 product of MODerate Resolution Imaging Spectroradiometer (MODIS). This band covers SR between 620 and 670nm, in which, the wavelength is sensitive to mineral suspended matters most. After elimination of days with cloud contamination, 118 pairs of data remained for analysis. Several possible functions were tested and exponential function was the best estimator of the SR-TSS and SR-TU relationships with R2 values of 0.8269 and 0.8688, respectively. We then used 2014 data to validate the proposed functions. The model was able to estimate TSS and TU with NRMSE values of 0.36 and 0.30. It indicates that the model can be well-applied to predict TSS and TU within a reasonable margin of error. Then, equations were used to map the spatiotemporal dynamics of sediment in GB. Area of the plume ranges between 12 to 180 km2 while 50% of the time the area of the turbid plume is more than 106 km2. Expectedly, the concentration of sediment is much higher

  15. Sedimentation rates and trace metal input history in intertidal sediments from San Simon Bay (Ria de Vigo, NW Spain) derived from 210Pb and 137Cs chronology

    International Nuclear Information System (INIS)

    Alvarez-Iglesias, Paula; Quintana, Begona; Rubio, Belen; Perez-Arlucea, Marta

    2007-01-01

    210 Pb and 137 Cs dating methods, accompanied by a high-resolution geochemical study, were applied to intertidal sediments containing both fine and coarse-grained particles and also, anthropogenic Pb in order to establish sedimentation rates and historical trends in heavy metal input. Sedimentation rates were established according to the 'Constant Flux:Constant Sedimentation' (CF:CS) 210 Pb dating model, which was preferred rather than the 'Constant Rate of Supply-Minimum Variance' (CRS-MV) model. Variations in sediment grain-size were accounted for by application of several normalization procedures. Al was selected for grain-size correction. Corrected sedimentation rates obtained from 210 Pb dating were corroborated through a second independent radionuclide tracer and by comparison of peak trace metal inputs into the environment with peaks in the sediment. The Chernobyl maximum was identified in the normalized 137 Cs activity profile. Sedimentation rates of 6.2 ± 1.2 mm y -1 and 3.1 ± 0.5 mm y -1 for the upper (two muddy layers) and 6.0 ± 2.0 mm y -1 for the lower (sandy) intertidal mud flat deposits of San Simon Bay were determined. According to the established chronology, human-induced environmental changes were detected in total metal concentrations (Cu, Pb, Zn) and in sediment grain-size and composition

  16. The Neoglacial landscape and human history of Glacier Bay, Glacier Bay National Park and Preserve, southeast Alaska, USA

    Science.gov (United States)

    Connor, C.; Streveler, G.; Post, A.; Monteith, D.; Howell, W.

    2009-01-01

    The Neoglacial landscape of the Huna Tlingit homeland in Glacier Bay is recreated through new interpretations of the lower Bay's fjordal geomorphology, late Quaternary geology and its ethnographic landscape. Geological interpretation is enhanced by 38 radiocarbon dates compiled from published and unpublished sources, as well as 15 newly dated samples. Neoglacial changes in ice positions, outwash and lake extents are reconstructed for c. 5500?????"200 cal. yr ago, and portrayed as a set of three landscapes at 1600?????"1000, 500?????"300 and 300?????"200 cal. yr ago. This history reveals episodic ice advance towards the Bay mouth, transforming it from a fjordal seascape into a terrestrial environment dominated by glacier outwash sediments and ice-marginal lake features. This extensive outwash plain was building in lower Glacier Bay by at least 1600 cal. yr ago, and had filled the lower bay by 500 cal. yr ago. The geologic landscape evokes the human-described landscape found in the ethnographic literature. Neoglacial climate and landscape dynamism created difficult but endurable environmental conditions for the Huna Tlingit people living there. Choosing to cope with environmental hardship was perhaps preferable to the more severely deteriorating conditions outside of the Bay as well as conflicts with competing groups. The central portion of the outwash plain persisted until it was overridden by ice moving into Icy Strait between AD 1724?????"1794. This final ice advance was very abrupt after a prolonged still-stand, evicting the Huna Tlingit from their Glacier Bay homeland. ?? 2009 SAGE Publications.

  17. Total petroleum hydrocarbons and heavy metals in the surface sediments of Bohai Bay, China: long-term variations in pollution status and adverse biological risk.

    Science.gov (United States)

    Zhou, Ran; Qin, Xuebo; Peng, Shitao; Deng, Shihuai

    2014-06-15

    Surface sediments collected from 2001 to 2011 were analyzed for total petroleum hydrocarbons (TPH) and five heavy metals. The sediment concentration ranges of TPH, Zn, Cu, Pb, Cd and Hg were 6.3-535 μg/g, 58-332 μg/g, 7.2-63 μg/g, 4.3-138 μg/g, 0-0.98μg/g, and 0.10-0.68 μg/g, respectively. These results met the highest marine sediment quality standards in China, indicating that the sediment was fairly clean. However, based on the effects range-median (ERM) quotient method, the calculated values for all of the sampling sites were higher than 0.10, suggesting that there was a potential adverse biological risk in Bohai Bay. According to the calculated results, the biological risk decreased from 2001 to 2007 and increased afterwards. High-risk sites were mainly distributed along the coast. This study suggests that anthropogenic influences might be responsible for the potential risk of adverse biological effects from TPH and heavy metals in Bohai Bay. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Increased terrestrial to ocean sediment and carbon fluxes in the northern Chesapeake Bay associated with twentieth century land alteration

    Science.gov (United States)

    Saenger, C.; Cronin, T. M.; Willard, D.; Halka, J.; Kerhin, R.

    2008-01-01

    We calculated Chesapeake Bay (CB) sediment and carbon fluxes before and after major anthropogenic land clearance using robust monitoring, modeling and sedimentary data. Four distinct fluxes in the estuarine system were considered including (1) the flux of eroded material from the watershed to streams, (2) the flux of suspended sediment at river fall lines, (3) the burial flux in tributary sediments, and (4) the burial flux in main CB sediments. The sedimentary maximum in Ambrosia (ragweed) pollen marked peak land clearance (~1900 a.d.). Rivers feeding CB had a total organic carbon (TOC)/total suspended solids of 0.24??0.12, and we used this observation to calculate TOC fluxes from sediment fluxes. Sediment and carbon fluxes increased by 138-269% across all four regions after land clearance. Our results demonstrate that sediment delivery to CB is subject to significant lags and that excess post-land clearance sediment loads have not reached the ocean. Post-land clearance increases in erosional flux from watersheds, and burial in estuaries are important processes that must be considered to calculate accurate global sediment and carbon budgets. ?? 2008 Coastal and Estuarine Research Federation.

  19. Lipid and DNA biomarker analyses of Narragansett Bay Sediments: Evaluating the UK'37 proxy in an Estuarine Environment

    Science.gov (United States)

    George, S. E.; Herbert, T.; Amaral-Zettler, L. A.; Richter, N.

    2017-12-01

    Long chain polyunsaturated alkenone (LCA) lipid biomarkers produced by haptophyte phytoplankton species within the Order Isochrysidales (Phylum Haptophyta) have proven exceptionally useful in paleotemperature studies by means of the Uk'37 and Uk37 indices. Two closely-related Group III haptophytes, Emiliania huxleyi and Gephyrocapsa oceanica are the primary alkenone synthesizers in the modern ocean, while freshwater systems host the distinct Group I phylotype, sometimes called the Greenland phylotype, in reference to the location of its original discovery. Group I haptophytes produce large quantities of the distinct C37:4 ketone, which acts as a chemical `fingerprint' in sediments. The utility of alkenones as a paleotemperature proxy in estuarine environments has remained largely untested, representing an under-utilized opportunity to construct high-resolution paleotemperature records from environments at the intersection of fluvial and marine systems. This uncertainty is due, in part, to the presence of multiple haptophyte groups in estuaries, resulting in a mixed alkenone signature. To determine the community composition of alkenone-producing haptophytes within Narragansett Bay, four geographically separated cores from within the Bay were analyzed for alkenones as well as haptophyte rRNA biomarker gene presence. Haptophyte rRNA genes (small and large subunit) were recovered from surface and near-subsurface samples, and in conjunction with alkenone profiles, reveal recent haptophyte community structure and alkenone production regimes throughout the Bay. A surprising result is the recovery of rRNA biomarker genes with a 100% match to the open-ocean alkenone producer E. huxleyi in locations away from large fresh water inputs to the Bay. Results of these analyses elucidate the effect of salinity and nutrient dynamics on alkenone-producing haptophyte communities and enhance applicability of long chain polyunsaturated alkenones as lipid biomarkers in estuarine

  20. Dinoflagellate cysts from surface sediments of Saldanha Bay, South Africa: an indication of the potential risk of harmful algal blooms

    CSIR Research Space (South Africa)

    Joyce, LB

    2005-02-01

    Full Text Available Africa bZoology Department, University Cape Town, Rondebosch 7701, Cape Town, South Africa cCouncil for Scientific and Industrial Research, P.O. Box 320, Stellenbosch 7759, South Africa Received 14 May 2004; received in revised form 21 July 2004; accepted... 15 August 2004 Abstract The distribution and abundance of dinoflagellate cysts from recent coastal sediments in Saldanha Bay, was investigated, and compared to the cyst assemblages of the adjacent coastal upwelling system as reflected in the sediments...

  1. Subtidal distribution of Exxon Valdez oil in two bays in Prince William Sound, Alaska

    International Nuclear Information System (INIS)

    Page, D.S.; Gilfillan, E.S.; Boehm, P.D.; Bence, A.E.; Burns, W.A.; Mankiewicz, P.J.

    1995-01-01

    This 1991 study assessed the subtidal fate of the Exxon Valdez oil spill in 2 bays. A subtidal stratified random sampling design compared stations in the oiled Bay of Isles with stations in the reference Drier Bay. Thirty-five random sampling stations over 3 depth zones in each of the oiled and reference bays enabled generalization of the results. 12 non-randomly chosen stations were also sampled in the two bays. Sediment samples were analyzed for saturate and aromatic hydrocarbons, grain size and organic carbon. The statistical comparisons between the oiled and reference bays were based on PAH analyses. Four types of PAH were identified in the two bays; Alaska North Slope (ANS) petrogenic spill PAH; seep-derived natural petrogenic background PAH; pyrogenic PAH; and diagenetic PAH (perylene). The Bay of Isles sediments contained significantly higher levels of weathered ANS-PAH than Drier Bay. These levels were generally small compared with those of the petrogenic background PAH naturally present. The concentration of the natural petrogenic PAH component increased with increasing depth zone for each bay. Drier Bay, a location of past cannery and mining activity, had significantly greater levels of pyrogenic PAH than the Bay of Isles. All sediment PAH concentrations were well below the 4,000 ng/g total PAH concentration reported in the literature as a sublethal toxicity threshold value in sediments. The highest sediment ANSPAH concentration (201 ng/g) was 20 times lower than this value

  2. Distribution, enrichment and sources of thallium in the surface sediments of the southwestern coastal Laizhou Bay, Bohai Sea.

    Science.gov (United States)

    Zhuang, Wen; Gao, Xuelu

    2015-07-15

    The concentrations of thallium (Tl) in the surface sediments of the southwestern coastal Laizhou Bay and the rivers it connects were determined. In riverine sediments, the Tl concentrations ranged from 0.34 to 0.76 μg g(-1) in summer; in autumn, the corresponding data were 0.35-1.08 μg g(-1). In marine sediments, the Tl concentrations ranged from 0.36 to 0.58 μg g(-1) in summer; and from 0.30 to 0.56 μg g(-1) in autumn. The grain size, Al and Fe oxides were major factors affecting Tl distribution. Tl in the surface sediments of the studied area was mainly from the natural input with the non-natural input as a subsidiary source. The low concentrations of Tl made it hard to cause potential negative environmental effects in this area. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Cobalt adsorption/desorption on sediments from Piraquara de Fora bay, Angra dos Reis, Brazil

    International Nuclear Information System (INIS)

    Ferreira, Ingryd M.; Carvalho, Franciane M.; Ribeiro, Fernando C.A.; Martins, Nadia S.F.; Peres, Sueli S.; Lauria, Dejanira C.

    2015-01-01

    Among the radionuclides released with the liquid effluents from PWR power plants, cobalt isotopes ( 60 Co and 58 Co) play an important role for risk and environmental impact assessments. The laboratory experiments on radionuclide adsorption-desorption, followed by the use of adsorption isotherms are useful tools for prediction of transport, distribution, accumulation, and fate of a contaminant into a specific medium. Adsorption and desorption experiments were carried out in batches, using two sediment samples collected in Piraquara de Fora Bay, near the discharge channel of the liquid effluents from CNAAA. Aiming the assessment of the radioisotope adsorption mechanisms, sediment samples were shaken with solutions containing cobalt chloride which concentrations ranged between 10 -10 and 10 -3 M. In order to estimate the efficiency of adsorption, 100 Bq of 60 Co were used as radioactive tracer. The experimental data fitted well with Freundlich and Langmuir isotherms. Results point out a favorable and high cobalt adsorption on the sediments, although smaller than the ones reported in literature studies. Such smaller trend of adsorption coefficients may be caused by the low exchange capacity of the prevailing clay, kaolinite. The maximum adsorption capacities were found to be 10 and 17 moles/g for sediments in PT-01 and PT-02, respectively. Values lower than 8% of the adsorbed cobalt underwent desorption and this amount decreased to 4%, with time, which show the high retention capacity of these sediments. (author)

  4. Storm-induced inner-continental shelf circulation and sediment transport: Long Bay, South Carolina

    Science.gov (United States)

    Warner, John C.; Armstrong, Brandy N.; Sylvester, Charlene S.; Voulgaris, George; Nelson, Tim; Schwab, William C.; Denny, Jane F.

    2012-01-01

    Long Bay is a sediment-starved, arcuate embayment located along the US East Coast connecting both South and North Carolina. In this region the rates and pathways of sediment transport are important because they determine the availability of sediments for beach nourishment, seafloor habitat, and navigation. The impact of storms on sediment transport magnitude and direction were investigated during the period October 2003–April 2004 using bottom mounted flow meters, acoustic backscatter sensors and rotary sonars deployed at eight sites offshore of Myrtle Beach, SC, to measure currents, water levels, surface waves, salinity, temperature, suspended sediment concentrations, and bedform morphology. Measurements identify that sediment mobility is caused by waves and wind driven currents from three predominant types of storm patterns that pass through this region: (1) cold fronts, (2) warm fronts and (3) low-pressure storms. The passage of a cold front is accompanied by a rapid change in wind direction from primarily northeastward to southwestward. The passage of a warm front is accompanied by an opposite change in wind direction from mainly southwestward to northeastward. Low-pressure systems passing offshore are accompanied by a change in wind direction from southwestward to southeastward as the offshore storm moves from south to north.During the passage of cold fronts more sediment is transported when winds are northeastward and directed onshore than when the winds are directed offshore, creating a net sediment flux to the north–east. Likewise, even though the warm front has an opposite wind pattern, net sediment flux is typically to the north–east due to the larger fetch when the winds are northeastward and directed onshore. During the passage of low-pressure systems strong winds, waves, and currents to the south are sustained creating a net sediment flux southwestward. During the 3-month deployment a total of 8 cold fronts, 10 warm fronts, and 10 low

  5. Determination of heavy metals and other elements in sediments from Sepetiba Bay (RJ, Brazil) by neutron activation analysis; Determinacao de metais pesados e outros elementos em sedimentos da Baia de Sepetiba (RJ) por ativacao neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Pellegatti, Fabio

    2000-07-01

    Sepetiba Bay, located about 60 km south of the city of Rio de Janeiro, Brazil, is one of the most important fishery areas in the State of Rio de Janeiro. A large harbor brought up a lot of industrial investment in that area. Since the 1970's, the Sepetiba region has undergone fast industrial expansion, leading to high levels of pollution by metals. For the last two decades, an industrial park composed of about 400 industrial plants, basically metallurgical, was established in the Sepetiba Bay basin, releasing its industrial waste either straight into the bay or through local rivers. Metal contamination in the bay for some metals, such as Zn, has already exceeded acceptable levels. Many authors have studied the distribution and behavior of heavy metals and another elements in the bay, but only few elements have been focused (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn). This is probably due to the fact that the analytical technique most employed has been atomic absorption spectrometry, which is not a multi-elemental technique. In this work, Instrumental Neutron Activation Analysis (INAA) was applied to the determination of the elements As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Nd, Rb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn in 28 bottom sediment samples and four sediment cores from Sepetiba Bay. The elements Co, Cr, Cs, Fe, Sc, Ta and Zn presented similar behavior in the bottom sediments, showing higher concentration along the Northern coast of the bay, where most of the fluvial water flows out to the bay. The contamination of Sepetiba Bay was also assessed by the analysis of four sediment cores. Two of them were sampled in the Eastern part of the bay, where the industrial park is located, whereas the other two were sampled in the Western part of the bay, a more preserved region. For each region, two cores were sampled within the mangrove trees and the others at the edge of the tidal flat. The results showed that, the sediments displayed higher metal concentration within

  6. The use of modeling and suspended sediment concentration measurements for quantifying net suspended sediment transport through a large tidally dominated inlet

    Science.gov (United States)

    Erikson, Li H.; Wright, Scott A.; Elias, Edwin; Hanes, Daniel M.; Schoellhamer, David H.; Largier, John; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Sediment exchange at large energetic inlets is often difficult to quantify due complex flows, massive amounts of water and sediment exchange, and environmental conditions limiting long-term data collection. In an effort to better quantify such exchange this study investigated the use of suspended sediment concentrations (SSC) measured at an offsite location as a surrogate for sediment exchange at the tidally dominated Golden Gate inlet in San Francisco, CA. A numerical model was calibrated and validated against water and suspended sediment flux measured during a spring–neap tide cycle across the Golden Gate. The model was then run for five months and net exchange was calculated on a tidal time-scale and compared to SSC measurements at the Alcatraz monitoring site located in Central San Francisco Bay ~ 5 km from the Golden Gate. Numerically modeled tide averaged flux across the Golden Gate compared well (r2 = 0.86, p-value

  7. Sub-tidal benthic habitats of central San Francisco Bay and offshore Golden Gate area: A review

    Science.gov (United States)

    Greene, H. Gary; Endris, Charles; Vallier, Tracy; Golden, Nadine E.; Cross, Jeffery; Ryan, Holly F.; Dieter, Bryan; Niven, Eric; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Deep-water potential estuarine and marine benthic habitat types were defined from a variety of new and interpreted data sets in central San Francisco Bay and offshore Golden Gate area including multibeam echosounder (MBES), side-scan sonar and bottom grab samples. Potential estuarine benthic habitats identified for the first time range from hard bedrock outcrops on island and mainland flanks and some Bay floor

  8. Inorganic As speciation and bioavailability in estuarine sediments of Todos os Santos Bay, BA, Brazil

    International Nuclear Information System (INIS)

    Hatje, V.; Macedo, S.M.; Jesus, R.M. de; Cotrim, G.; Garcia, K.S.; Queiroz, A.F. de; Ferreira, S.L.C.

    2010-01-01

    Research highlights: → Total concentration of As at several stations along Todos os Santos Bay, was above TEL value. → At Subae and Paraguacu systems, As (V) was the dominant species, which is less toxic and less mobile than As (III). → Arsenic concentrations at Jaguaripe estuary were higher than in other estuaries and As (III) was the dominant species. → Relationship between As, Fe, Mn and sand indicated that As enrichment at Jaguaripe River is natural. → As concentrations in sediments and biota suggest that As is bioavailable and it is accumulating in marine organisms, which may impose human risks. → Slurry sampling showed to be a easy, accurate procedure to be used for As determination in estuarine samples. - Abstract: The spatial distribution of As (total As, As (III) and As (V)) in estuarine sediments from the main tributaries of Todos os Santos Bay, BA, Brazil, was evaluated under high and low flow conditions. The concentrations of As were determined using a slurry sampling procedure with hydride generation atomic absorption spectrometry (HG-AAS). The highest concentrations were observed at estuary mouths, and exceeded conservative lower threshold value (Threshold Effects Level; TEL). Due to the oxic conditions and abundance of Mn and Fe (oxyhydr)oxides in the sediments, most inorganic arsenic in the Subae and Paraguacu estuaries was present as As (V). Nevertheless, the concentration of As (III) at several locations along the Jaguaripe River were also above the TEL value, suggesting that As may be toxic to biota. In the Subae estuary, antropogenic activities are the main source of As. At the Jaguaripe and at Paraguacu estuaries, nevertheless, natural sources of As need to be considered to explain the distribution patterns.

  9. Spatio-temporal changes in totally and enzymatically hydrolyzable amino acids of superficial sediments from three contrasted areas

    Science.gov (United States)

    Grémare, Antoine; Gutiérrez, Dimitri; Anschutz, Pierre; Amouroux, Jean Michel; Deflandre, Bruno; Vétion, Gilles

    2005-04-01

    Spatio-temporal changes in totally and enzymatically hydrolyzable amino acids (THAA and EHHA) and EHAA/THAA ratios of superficial sediments were assessed during 1997-1999 in three areas (i.e., the Gulf of Lions, the Bay of Biscay, and Central Chile) differing in their primary productivity. In all three areas, and even off Central Chile where a strong El Niño event took place during 1997-1998, spatial changes were always much greater than temporal ones. The factors affecting the spatial distributions of amino acid concentrations differed among areas. In the Gulf of Lions, sediment granulometry was apparently the most important driving force of THAA, EHAA, and EHAA/THAA, and there was no marked difference between stations located on the open slope and those in submarine canyons. Conversely, in the Bay of Biscay, there were clear differences between the stations located off Cap-Breton, on the open slope, and those in the Cap-Ferret canyon; the latter two featuring lower EHAA and THAA but higher EHAA/THAA. This pattern is likely to result from the predominance of different sources of organic matter and especially from the importance of continental inputs to the Cap-Breton canyon. Off Central Chile, amino acid concentrations and ratios were both maximal around 100 m depth, probably reflecting the interaction between the primary productivity gradient and the presence of an oxygen minimum zone (OMZ) reducing the degradation of sedimentary organics. When comparing the average values collected in the three areas studied, THAA and EHAA were highest in Central Chile, intermediate in the Bay of Biscay and lowest in the Gulf of Lions. EHAA/THAA ratios were also highest in Central Chile but were lowest in the Bay of Biscay. Differences between the Gulf of Lions and the Bay of Biscay could have been affected by sampling design. In Central Chile, the use of labile organic carbon to total organic carbon (C-LOM/TOC) and EHAA/THAA as indices of organic matter lability led to very

  10. Bioavailability of heavy metals in water and sediments from a typical Mediterranean Bay (Málaga Bay, Region of Andalucía, Southern Spain).

    Science.gov (United States)

    Alonso Castillo, M L; Sánchez Trujillo, I; Vereda Alonso, E; García de Torres, A; Cano Pavón, J M

    2013-11-15

    Concentrations of heavy metals were measured in sediment and water from Málaga Bay (South Spain). In the later twentieth century, cities such as Málaga, have suffered the impact of mass summer tourism. The ancient industrial activities, and the actual urbanization and coastal development, recreation and tourism, wastewaters treatment facilities, have been sources of marine pollution. In sediments, Ni was the most disturbing metal because Ni concentrations exceeded the effects range low (ERL), concentration at which toxicity could start to be observed in 85% of the samples analyzed. The metal bioavailability decreased in the order: Cd>Ni>Pb>Cu>Cr. In the sea water samples, Cd and Pb were the most disturbing metals because they exceeded the continuous criteria concentration (CCC) of US EPA in a 22.5% and 10.0% of the samples, respectively. Statistical analyses (ANOVA, PCA, CA) were performed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Modelling of Sediment Transport in Beris Fishery Port

    Directory of Open Access Journals (Sweden)

    Samira Ardani

    2015-06-01

    Full Text Available In this paper, the large amount of sedimentation and the resultant shoreline advancements at the breakwaters of Beris Fishery Port are studied. A series of numerical modeling of waves, sediment transport, and shoreline changes were conducted to predict the complicated equilibrium shoreline. The outputs show that the nearshore directions of wave components are not perpendicular to the coast which reveals the existence of longshore currents and consequently sediment transport along the bay. Considering the dynamic equilibrium condition of the bay, the effect of the existing sediment resources in the studied area is also investigated. The study also shows that in spite of the change of the diffraction point of Beris Bay after the construction of the fishery port, the bay is approaching its dynamic equilibrium condition, and the shoreline advancement behind secondary breakwater will stop before blocking the entrance of the port. The probable solutions to overcome the sedimentation problem at the main breakwater are also discussed.

  12. Effect of Coarse Particle Volume Fraction on the Yield Stress of Muddy Sediments from Marennes Oléron Bay

    Directory of Open Access Journals (Sweden)

    A. Pantet

    2010-01-01

    Full Text Available Coastal erosion results from a combination of various factors, both natural and humaninduced, which have different time and space patterns. In addition, uncertainties still remain about the interactions of the forcing agents, as well as on the significance of non-local causes of erosion. We focused about the surface sediments in the Marennes Oléron bay, after a general description of the site that has many various activities. The superficial sediments show a mechanical behavior, mainly depends on the fine fraction for a composition that contains up to 60% of sandy material. Fine sediments fraction has a typical yield stress depending naturally of concentration or water content. This yield could be modified slightly or significantly by adding silt or sand. As a result, the rheological measurement sensitivity allows us to characterize five typical sediments that correlate with solid fraction and fine fraction.

  13. The impact of urban expansion and agricultural legacies on trace metal accumulation in fluvial and lacustrine sediments of the lower Chesapeake Bay basin, USA.

    Science.gov (United States)

    Coxon, T M; Odhiambo, B K; Giancarlo, L C

    2016-10-15

    The progressively declining ecological condition of the Chesapeake Bay is attributed to the influx of contaminants associated with sediment loads supplied by its largest tributaries. The continued urban expansion in the suburbs of Virginia cities, modern agricultural activities in the Shenandoah Valley, the anthropogenic and climate driven changes in fluvial system hydrodynamics and their potential associated impacts on trace metals enrichment in the bay's tributaries necessitate constant environmental monitoring of these important water bodies. Eight (210)Pb and (137)Cs dated sediment cores and seventy two sediment grab samples were used to analyze the spatial and temporal distributions of Al, Ca, Mg, Cr, Cd, As, Se, Pb, Cu, Zn, Mn, and Fe in the waterways of the Virginia portion of the Chesapeake Bay basin. The sediment cores for trace metal historical fluctuation analysis were obtained in lower fluvial-estuarine environments and reservoirs in the upper reaches of the basin. The trace metal profiles revealed high basal enrichment factors (EF) of between 0.05 and 40.24, which are interpreted to represent early nineteenth century agricultural activity and primary resource extraction. Surficial enrichment factors on both cores and surface grab samples ranged from 0.01 (Cu) to 1421 (Cd), with Pb, Cu, Zn, and Cd enrichments a plausible consequence of modern urban expansion and industrial development along major transportation corridors. Contemporary surficial enrichments of As, Se, and Cr also ranged between 0 and 137, with the higher values likely influenced by lithological and atmospheric sources. Pearson correlation analyses suggest mining and agricultural legacies, coupled with aerosol deposition, are responsible for high metal concentrations in western lakes and headwater reaches of fluvial systems, while metal accumulation in estuarine reaches of the major rivers can be attributed to urban effluence and the remobilization of legacy sediments. Copyright © 2016

  14. Measurements of gaseous mercury exchanges at the sediment-water, water-atmosphere and sediment-atmosphere interfaces of a tidal environment (Arcachon Bay, France).

    Science.gov (United States)

    Bouchet, Sylvain; Tessier, Emmanuel; Monperrus, Mathilde; Bridou, Romain; Clavier, Jacques; Thouzeau, Gerard; Amouroux, David

    2011-05-01

    The elemental mercury evasion from non-impacted natural areas is of significant importance in the global Hg cycle due to their large spatial coverage. Intertidal areas represent a dynamic environment promoting the transformations of Hg species and their subsequent redistribution. A major challenge remains in providing reliable data on Hg species variability and fluxes under typical transient tidal conditions found in such environment. Field experiments were thus carried out to allow the assessment and comparison of the magnitude of the gaseous Hg fluxes at the three interfaces, sediment-water, sediment-atmosphere and water-atmosphere of a mesotidal temperate lagoon (Arcachon Bay, Aquitaine, France) over three distinct seasonal conditions. The fluxes between the sediment-water and the sediment-atmosphere interfaces were directly evaluated with field flux chambers, respectively static or dynamic. Water-atmosphere fluxes were evaluated from ambient concentrations using a gas exchange model. The fluxes at the sediment-water interface ranged from -5.0 to 5.1 ng m(-2) h(-1) and appeared mainly controlled by diffusion. The occurrence of macrophytic covers (i.e.Zostera noltii sp.) enhanced the fluxes under light radiations. The first direct measurements of sediment-atmosphere fluxes are reported here. The exchanges were more intense and variable than the two other interfaces, ranging between -78 and 40 ng m(-2) h(-1) and were mostly driven by the overlying atmospheric Hg concentrations and superficial sediment temperature. The exchanges between the water column and the atmosphere, computed as a function of wind speed and gaseous mercury saturation ranged from 0.4 to 14.5 ng m(-2) h(-1). The flux intensities recorded over the intertidal sediments periodically exposed to the atmosphere were roughly 2 to 3 times higher than the fluxes of the other interfaces. The evasion of elemental mercury from emerged intertidal sediments is probably a significant pathway for Hg evasion in

  15. Spatial variation, speciation and sedimentary records of mercury in the Guanabara Bay (Rio de Janeiro, Brazil)

    Science.gov (United States)

    Covelli, Stefano; Protopsalti, Ioanna; Acquavita, Alessandro; Sperle, Marcelo; Bonardi, Maurizio; Emili, Andrea

    2012-03-01

    As part of the "TAGUBAR" (TAngential GUanabara Bay Aeration Recovery) project, surface and long core sediments of the Guanabara Bay (Rio de Janeiro, Brazil) were investigated for mercury (Hg). The main, but not the only, input of Hg into the Bay's waters is known to be a Chlor-Alkali Plant (CAP) located in the Acarì-São João de Merití River system, on the northwestern side of the Bay. Mercury distribution in surface sediments (<0.1-3.22 mg kg-1, average 0.87±0.80, n=40) seems to be controlled by the organic component, along with sulfur rather than grain-size, where Hg concentrations are less than 1 mg kg-1. Conversely, where the metal contents are higher than 1 mg kg-1, accumulation in surface sediments is mostly related to the presence of nearby contamination sources, such as industrial and urban settlements in the western sector of the Bay. Although total Hg contents in surface sediments exceed the values suggested by the effects-based standard quality guidelines as potentially toxic for the benthic community, results from a sequential extraction procedure showed that the contribution of the more soluble, easily exchangeable and eventually bioavailable Hg phases was found almost negligible (<0.1%). Most of the metal is strongly bound to the mineral lattice of the sedimentary matrix and should therefore be considered almost immobilized. The reduction in Hg accumulation in bottom sediments, expected as a consequence of the adoption of contamination control policies (i.e. Hg-free technologies in the CAP and sewage treating facilities), has not been clearly observed in the core profiles. Current estimates of Hg accumulation rates at the core top range from approximately 1 to 18 mg m-2 yr-1. Pre-industrial bottom core samples indicate that the central and northeastern sectors of the Bay are strongly affected by Hg enrichment: concentrations exceed the estimated baseline concentration by up to 20 factors. A cumulative Hg inventory suggests that the metal content

  16. PAH Baselines for Amazonic Surficial Sediments: A Case of Study in Guajará Bay and Guamá River (Northern Brazil).

    Science.gov (United States)

    Rodrigues, Camila Carneiro Dos Santos; Santos, Ewerton; Ramos, Brunalisa Silva; Damasceno, Flaviana Cardoso; Correa, José Augusto Martins

    2018-06-01

    The 16 priority PAH were determined in sediment samples from the insular zone of Guajará Bay and Guamá River (Southern Amazon River mouth). Low hydrocarbon levels were observed and naphthalene was the most representative PAH. The low molecular weight PAH represented 51% of the total PAH. Statistical analysis showed that the sampling sites are not significantly different. Source analysis by PAH ratios and principal component analysis revealed that PAH are primary from a few rate of fossil fuel combustion, mainly related to the local small community activity. All samples presented no biological stress or damage potencial according to the sediment quality guidelines. This study discuss baselines for PAH in surface sediments from Amazonic aquatic systems based on source determination by PAH ratios and principal component analysis, sediment quality guidelines and through comparison with previous studies data.

  17. Rapid deterioration of sediment surface habitats in Bellingham Bay, Washington State, as indicated by benthic foraminifera.

    Science.gov (United States)

    Nesbitt, Elizabeth A; Martin, Ruth A; Martin, David E; Apple, Jude

    2015-08-15

    Foraminiferal assemblages in sediment grab samples were utilized to evaluate the impacts of anthropogenic activities on benthic habitats in Bellingham Bay, Washington State, U.S.A. Seventy-three samples taken in 1987, 1997, 2006 and 2010 yielded 35 species of foraminifera from 28 genera. Assemblage composition and diversity data indicate a marked deterioration between 1987 and 2010, contrary to the published Chemical Index, but analogous to the situation with macrobiota. Correlation of diversity with chemical pollutants and metals did not identify any significant correlations, however, an unrelated but highly relevant study of bottom water dissolved oxygen concentrations and pH in Bellingham Bay suggests eutrophication with accompanying hypoxia and acidification may be part of the cause. Thus, the metrics of contamination alone do not adequately characterize habitat viability, and benthic foraminiferal assemblages provide insight into the health of coastal ecosystems. Published by Elsevier Ltd.

  18. Sedimentological characteristics and depositional processes of sediment gravity flows in rift basins: The Palaeogene Dongying and Shahejie formations, Bohai Bay Basin, China

    Science.gov (United States)

    Liu, Lei; Chen, Hongde; Zhong, Yijiang; Wang, Jun; Xu, Changgui; Chen, Anqing; Du, Xiaofeng

    2017-10-01

    Sediment gravity flow deposits are common, particularly in sandy formations, but their origin has been a matter of debate and there is no consensus about the classification of such deposits. However, sediment gravity flow sandstones are economically important and have the potential to meet a growing demand in oil and gas exploration, so there is a drive to better understand them. This study focuses on sediment gravity flow deposits identified from well cores in Palaeogene deposits from the Liaodong Bay Depression in Bohai Bay Basin, China. We classify the sediment gravity flow deposits into eight lithofacies using lithological characteristics, grain size, and sedimentary structures, and interpret the associated depositional processes. Based on the scale, spatial distribution, and contact relationships of sediment gravity flow deposits, we defined six types of lithofacies associations (LAs) that reflect transformation processes and depositional morphology: LA1 (unconfined proximal breccia deposits), LA2 (confined channel deposits), LA3 (braided-channel lobe deposits), LA4 (unconfined lobe deposits), LA5 (distal sheet deposits), and LA6 (non-channelized sheet deposits). Finally, we established three depositional models that reflect the sedimentological characteristics and depositional processes of sediment gravity flow deposits: (1) slope-apron gravel-rich depositional model, which involves cohesive debris flows deposited as LA1 and dilute turbidity currents deposited as LA5; (2) non-channelized surge-like turbidity current depositional model, which mainly comprises sandy slumping, suspended load dominated turbidity currents, and dilute turbidity currents deposited as LA5 and LA6; and (3) channelized subaqueous-fan depositional model, which consists of non-cohesive bedload dominated turbidity currents, suspended load dominated turbidity currents, and dilute turbidity currents deposited as LA2-LA5, originating from sustained extrabasinal turbidity currents

  19. Impact of industrial pollution on recent dinoflagellate cysts in Izmir Bay (Eastern Aegean).

    Science.gov (United States)

    Aydin, Hilal; Yürür, Emine Erdem; Uzar, Serdar; Küçüksezgin, Filiz

    2015-05-15

    The spatial distribution of dinoflagellate cysts was studied to understand the impact of industrial pollution on the surface sediment of Izmir Bay, Turkey. Forty two dinoflagellate cyst morphotypes belonging to 12 genera were identified and qualified at 12 sampling points. The cyst of Gymnodinium nolleri dominated the bay and had the highest abundance in most of the stations, following Spiniferites bulloideus and Lingulodinium machaerophorum. The highest cyst concentration was recorded in the inner part of the bay. Cyst concentration ranged between 384 and 9944 cyst g(-1) dry weight of sediment in the sampling area. Sediment metal concentrations were determined. Heavy metal levels in Izmir Inner Bay were higher than the Middle and Outer Bay. L. machaerophorum, Dubridinium caperatum and Polykrikos kofoidii showed significant positive correlation with some metals (Cd, Pb, Cu, Zn) and organic carbon content. However, there was no significant correlation between dinoflagellate cyst abundance and sediment type. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. National Status and Trends: Bioeffects Program - Magnitude and Extent of Sediment Toxicity in Four Bays of the Florida Panhandle: Pensacola, Choctawhatchee, St. Andrew and Apalachicola

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The toxicity of sediments in Pensacola, Choctawhatchee, St. Andrew and Apalachicola Bays was determined as part of bioeffects assessments performed by NOAA's...

  1. Multivariate Analyses and Evaluation of Heavy Metals by Chemometric BCR Sequential Extraction Method in Surface Sediments from Lingdingyang Bay, South China

    Directory of Open Access Journals (Sweden)

    Linglong Cao

    2015-04-01

    Full Text Available Sediments in estuary areas are recognized as the ultimate reservoirs for numerous contaminants, e.g., toxic metals. Multivariate analyses by chemometric evaluation were performed to classify metal ions (Cu, Zn, As, Cr, Pb, Ni and Cd in superficial sediments from Lingdingyang Bay and to determine whether or not there were potential contamination risks based on the BCR sequential extraction scheme. The results revealed that Cd was mainly in acid-soluble form with an average of 75.99% of its total contents and thus of high potential availability, indicating significant anthropogenic sources, while Cr, As, Ni were enriched in the residual fraction which could be considered as the safest ingredients to the environment. According to the proportion of secondary to primary phases (KRSP, Cd had the highest bioavailable fraction and represented high or very high risk, followed by Pb and Cu with medium risks in most of samples. The combined evaluation of the Pollution Load Index (PLI and the mean Effect Range Median Quotient (mERM-Q highlighted that the greatest potential environmental risk area was in the northwest of Lingdingyang Bay. Almost all of the sediments had a 21% probability of toxicity. Additionally, Principal Component Analysis (PCA revealed that the survey region was significantly affected by two main sources of anthropogenic contributions: PC1 showed increased loadings of variables in acid-soluble and reducible fractions that were consistent with the input from industrial wastes (such as manufacturing, metallurgy, chemical industry and domestic sewages; PC2 was characterized by increased loadings of variables in residual fraction that could be attributed to leaching and weathering of parent rocks. The results obtained demonstrated the need for appropriate remediation measures to alleviate soil pollution problem due to the more aggregation of potentially risky metals. Therefore, it is of crucial significance to implement the targeted

  2. Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California

    Science.gov (United States)

    Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.

    2006-01-01

    This report presents a map and database of Quaternary deposits and liquefaction susceptibility for the urban core of the San Francisco Bay region. It supercedes the equivalent area of U.S. Geological Survey Open-File Report 00-444 (Knudsen and others, 2000), which covers the larger 9-county San Francisco Bay region. The report consists of (1) a spatial database, (2) two small-scale colored maps (Quaternary deposits and liquefaction susceptibility), (3) a text describing the Quaternary map and liquefaction interpretation (part 3), and (4) a text introducing the report and describing the database (part 1). All parts of the report are digital; part 1 describes the database and digital files and how to obtain them by downloading across the internet. The nine counties surrounding San Francisco Bay straddle the San Andreas fault system, which exposes the region to serious earthquake hazard (Working Group on California Earthquake Probabilities, 1999). Much of the land adjacent to the Bay and the major rivers and streams is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment. This new map provides a consistent detailed treatment of the central part of the 9-county region in which much of the mapping of Open-File Report 00-444 was either at smaller (less detailed) scale or represented only preliminary revision of earlier work. Like Open-File Report 00-444, the current mapping uses geomorphic expression, pedogenic soils, inferred depositional environments, and geologic age to define and distinguish the map units. Further scrutiny of the factors controlling liquefaction susceptibility has led to some changes relative to Open-File Report 00-444: particularly the reclassification of San Francisco Bay mud (Qhbm) to have only MODERATE susceptibility and the rating of artificial fills according to the Quaternary map units inferred to underlie them (other than dams - adf). The two colored

  3. Coastal ocean transport patterns in the central Southern California Bight

    Science.gov (United States)

    Noble, M.A.; Rosenberger, K.J.; Hamilton, P.; Xu, J. P.

    2009-01-01

    In the past decade, several large programs that monitor currents and transport patterns for periods from a few months to a few years were conducted by a consortium of university, federal, state, and municipal agencies in the central Southern California Bight, a heavily urbanized section of the coastal ocean off the west coast of the United States encompassing Santa Monica Bay, San Pedro Bay, and the Palos Verdes shelf. These programs were designed in part to determine how alongshelf and cross-shelf currents move sediments, pollutants, and suspended material through the region. Analysis of the data sets showed that the current patterns in this portion of the Bight have distinct changes in frequency and amplitude with location, in part because the topography of the shelf and upper slope varies rapidly over small spatial scales. However, because the mean, subtidal, and tidal-current patterns in any particular location were reasonably stable with time, one could determine a regional pattern for these current fields in the central Southern California Bight even though measurements at the various locations were obtained at different times. In particular, because the mean near-surface flows over the San Pedro and Palos Verdes shelves are divergent, near-surface waters from the upper slope tend to carry suspended material onto the shelf in the northwestern portion of San Pedro Bay. Water and suspended material are also carried off the shelf by the mean and subtidal flow fields in places where the orientation of the shelf break changes abruptly. The barotropic tidal currents in the central Southern California Bight flow primarily alongshore, but they have pronounced amplitude variations over relatively small changes in alongshelf location that are not totally predicted by numerical tidal models. Nonlinear internal tides and internal bores at tidal frequencies are oriented more across the shelf. They do not have a uniform transport direction, since they move fine sediment

  4. Historical trend in heavy metal pollution in core sediments from the Masan Bay, Korea.

    Science.gov (United States)

    Cho, Jinhyung; Hyun, Sangmin; Han, J-H; Kim, Suhyun; Shin, Dong-Hyeok

    2015-06-15

    The spatiotemporal distribution and their mass accumulation rate (MAR) of heavy metals were investigated to evaluate the time-dependent historical trends of heavy metal concentration. The three short cores used for this study were collected from the catchment area (MS-PC5, 60cm length), the central part (MS-PC4, 40cm length) and the offshore (MS-PC2, 60cm length) of the Masan Bay, Korea. The concentration of heavy metals (Co, Ni, Cu, Zn, Cr and Pb) in catchment area is as much as 1.5-2 times higher than central part of the Bay, and about 2 times higher than offshore area approximately. In particular, MAR of metals (Cu, Zn and Pb) show clear spatiotemporal variation, so that MAR's of heavy metal may provide more accurate information in evaluating the degree of pollution. Temporally, the heavy metal concentration had been increased since the late 1970s, but it seems to decrease again since the 2004yr in catchment area. This may came from concentrated efforts for the government to reduce industrial waste release. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Determination of the sedimentation rates in the Sepetiba bay northeastern area by using dating with the excesses 210 Pb radioisotope

    International Nuclear Information System (INIS)

    Forte, Cristiane Maria Sampaio

    1996-01-01

    210 Pb dating, using two modes of data analysis, CIC and CRS, was used to determine sedimentation in the North East part of Sepetiba Bay. 210 Pb was leached from samples using dilute HBr and subsequently separated onto anionic exchange columns, followed by re-extraction and precipitation as Pb CrO 4 . The original method was modified by the introduction of a pre-digestion step whose purpose was to liberate the lead bound as sulphide. The sedimentation rates found o.68 - 0.98 cm.y -1 were moderate, compared to other authors estimates. Dating using the CRS model showed a maximum rate of sedimentation in the period between 1954 and 1977, when the riverine input was probably at its greatest. The CRS model appears to be more applicable to the data, since it works over longer periods and allows for variations in sedimentation rate. (author)

  6. Pairing Coral Geochemical Analyses with an Ecosystem Services Model to Assess Drivers and Impacts of Sediment Delivery within Micronesia's Largest Estuary, Ngeremeduu Bay

    Science.gov (United States)

    Lewis, S.; Dunbar, R. B.; Mucciarone, D.; Barkdull, M.

    2017-12-01

    Scientific tools assessing impacts to watershed and coastal ecosystem services, like those from land-use land conversion (LULC), are critical for sustainable land management strategies. Small island nations are particularly vulnerable to LULC threats, especially sediment delivery, given their small spatial size and reliance on natural resources. In the Republic of Palau, a small Pacific island country, three major land-use activities—construction, fires, and agriculture— have increased sediment delivery to important estuarine and coastal habitats (i.e., rivers, mangroves, coral reefs) over the past 30 years. This project examines the predictive capacity of an ecosystem services model, Natural Capital Project's InVEST, for sediment delivery using historic land-use and coral geochemical analysis. These refined model projections are used to assess ecosystem services tradeoffs under different future land development and management scenarios. Coral cores (20-41cm in length) were sampled along a high-to-low sedimentation gradient (i.e., near major rivers (high-impact) and ocean (low-impact)) in Micronesia's largest estuary, Ngeremeduu Bay. Isotopic indicators of seasonality (δ18O and δ13C values (% VPDB)) were used to construct the age model for each core. Barium, Manganese, and Yttrium were used as trace metal proxies for sedimentation and measured in each core using a laser ablation ICP-MS. Finally, the Natural Capital Project's InVEST sediment delivery model was paired with Geospatial data to examine the drivers of sediment delivery (i.e., construction, farms and fires) within these two watersheds. A thirty-year record of trace metal to calcium ratios in coral skeletons show a peak in sedimentation during 2006 and 2007, and in 2012. These results suggest historic peaks in sediment delivery correlating to large-scale road construction and support previous findings that Ngeremeduu Bay has reached a tipping point of retaining sediment. Natural Capital's project In

  7. Distribution and geochemical speciation of heavy metals in sediments from coastal area suffered rapid urbanization, a case study of Shantou Bay, China.

    Science.gov (United States)

    Qiao, Yongmin; Yang, Yang; Gu, Jiguang; Zhao, Jiangang

    2013-03-15

    Eight metals in sediment samples at 15 sites from the Shantou Bay were analyzed with BCR sequential extraction protocol to obtain the metal distribution patterns in the bay. The results showed that the heavy metal pollutions in upper bay were more severe than in middle and down reaches of the bay. Both total and non-residual fractions of metals with a exception of Mn showed a seaward decrease trend. More than 54% of the total concentrations of Cd, Mn and Zn existed in the acid soluble fraction. Ni, Co, Cr and Fe mainly (more than 51%) occurred in the residual fraction. While Pb and Cu dominantly presented in the reducible (50%) and oxidable (33%) fraction respectively. Principal component analysis (PCA) revealed that the heavy metals in the non-residual fractions resulted from largely anthropogenic sources, including river input, city runoff and port discharge. These contributing sources are highlighted by cluster analysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Determination of some elements in bottom sediments from Varna Bay, Bulgaria, and Saronikos Gluf, Greece

    International Nuclear Information System (INIS)

    Apostolov, D.; Jovchev, M.; Kinova, L.; Nikolov, P.; Penev, I.; Taskaev, E.; Grigorov, T.; Stoyanov, A.

    1985-01-01

    The concentrations of 16 trace elements (Ce, Co, Cr, Eu, Cs, Fe, Hf, La, Mg, Mn, Rb, Sb, Sc, Sm and V) in bottom sediments and in flesh and liver of Gobius niger were determined by means of instrumental neutron activation analysis. The samples were collected from the upper 5 cm layer of of the bottom sedimements together with fish from 5 points of Varna Bay and from 2 points of Saronicos Gulf in the summer of 1980. The results obtained proved to be important in investigating the ecological role of elements determined in connection with human activity in the studied area

  9. Seagrass vegetation and meiofauna enhance the bacterial abundance in the Baltic Sea sediments (Puck Bay).

    Science.gov (United States)

    Jankowska, Emilia; Jankowska, Katarzyna; Włodarska-Kowalczuk, Maria

    2015-09-01

    This study presents the first report on bacterial communities in the sediments of eelgrass (Zostera marina) meadows in the shallow southern Baltic Sea (Puck Bay). Total bacterial cell numbers (TBNs) and bacteria biomass (BBM) assessed with the use of epifluorescence microscope and Norland's formula were compared between bare and vegetated sediments at two localities and in two sampling summer months. Significantly higher TBNs and BBM (PERMANOVA tests, P PERMANOVA distance-based linear model (DISTLM) procedures and showed that the main factors explaining bacteria characteristics are bottom type (vegetated vs. unvegetated) and meiofauna density. These two factors explained together 48.3% of variability in TBN and 40.5% in BBM, and their impacts did not overlap (as indicated by DISTLM sequential tests) demonstrating the different natures of these relationships. The effects of seagrass were most probably related to the increase of organic matter and providing habitat while higher numbers of meiofauna organisms may have stimulated the bacterial growth by increased grazing.

  10. Brominated diphenyl ethers in the sediments, porewater, and biota of the Chesapeake Bay, USA

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K.; Klosterhaus, S.; Liebert, D.; Stapleton, H. [Maryland Univ., Solomons, MD (United States)

    2004-09-15

    Levels of brominated diphenyl ethers (BDEs) are rapidly increasing in the environment, and in a short time these chemicals have evolved from 'emerging contaminants' to globally-distributed organic pollutants. Recent research demonstrates BDEs are sufficiently stable to be transported long distances in the environment and to accumulate in higher trophic levels. Photolysis and metabolism appear to be dominant loss processes for the parent compounds, generating a variety of lower brominated diphenyl ethers, hydroxylated metabolites, and other products. BDEs are hydrophobic, and therefore their transport in aquatic systems is likely controlled by sorption to sediments and perhaps exchange across the air-water interface. To date, few studies have examined the geochemistry of BDEs in natural waters. In this paper, we review our recent measurements of BDEs in the Chesapeake Bay, a shallow, productive estuary in eastern North America. We focus on the distribution of BDE congeners sediment, porewater, and in faunal benthos along a contamination gradient downstream from a wastewater treatment plant and on the spatial distribution of BDEs in bottom-feeding and pelagic fish species.

  11. Assessment of the mobility of metals and semi-metals in Sepetiba Bay (Rio de Janeiro - Brazil) by analyzing sediments sampled in different periods

    International Nuclear Information System (INIS)

    Cortez, Vinicius D.; Ribeiro, Andreza P.; Figueiredo, Ana M.G.; Santos, Jose O.; Wassermann, Julio C.

    2005-01-01

    In the last three decades, Sepetiba bay, located about 60 km south of the city of Rio de Janeiro, Brazil, has been subjected to increasing pollution impacts. The Sepetiba region has undergone fast industrial expansion leading to high levels of pollution by metals. For the last two decades, an industrial park composed of about 400 industrial plants, basically metallurgical, was established in the Sepetiba Bay basin, releasing its effluents either straight into the bay or through local rivers. Potential toxic elements such as As, Zn, Cr, Pb and Cd have been introduced into the bay through industrial and domestic wastes. In the present paper, instrumental neutron activation analysis (INAA) was applied to determine the elements As, Cr and Zn in sediments from Sepetiba bay, sampled in August 2003, in order to compare to previous results obtained in 1998, for these elements, by Pellegatti et al. (2001). By using a geostatistical model it was possible to evaluate the spatial mobility of As, Cr and Zn in the last six years. The results obtained showed that none of the studied elements showed a significant spatial mobility. This behavior is probably related to geochemical barriers present in Sepetiba bay. (author)

  12. Deep drilling in the Chesapeake Bay impact structure - An overview

    Science.gov (United States)

    Gohn, G.S.; Koeberl, C.; Miller, K.G.; Reimold, W.U.

    2009-01-01

    The late Eocene Chesapeake Bay impact structure lies buried at moderate depths below Chesapeake Bay and surrounding landmasses in southeastern Virginia, USA. Numerous characteristics made this impact structure an inviting target for scientific drilling, including the location of the impact on the Eocene continental shelf, its threelayer target structure, its large size (??85 km diameter), its status as the source of the North American tektite strewn field, its temporal association with other late Eocene terrestrial impacts, its documented effects on the regional groundwater system, and its previously unstudied effects on the deep microbial biosphere. The Chesapeake Bay Impact Structure Deep Drilling Project was designed to drill a deep, continuously cored test hole into the central part of the structure. A project workshop, funding proposals, and the acceptance of those proposals occurred during 2003-2005. Initial drilling funds were provided by the International Continental Scientific Drilling Program (ICDP) and the U.S. Geological Survey (USGS). Supplementary funds were provided by the National Aeronautics and Space Administration (NASA) Science Mission Directorate, ICDP, and USGS. Field operations were conducted at Eyreville Farm, Northampton County, Virginia, by Drilling, Observation, and Sampling of the Earth's Continental Crust (DOSECC) and the project staff during September-December 2005, resulting in two continuously cored, deep holes. The USGS and Rutgers University cored a shallow hole to 140 m in April-May 2006 to complete the recovered section from land surface to 1766 m depth. The recovered section consists of 1322 m of crater materials and 444 m of overlying postimpact Eocene to Pleistocene sediments. The crater section consists of, from base to top: basement-derived blocks of crystalline rocks (215 m); a section of suevite, impact melt rock, lithic impact breccia, and cataclasites (154 m); a thin interval of quartz sand and lithic blocks (26 m); a

  13. Quantifying the erosion processes and land-uses which dominate fine sediment supply to Moreton Bay, Southeast Queensland, Australia

    International Nuclear Information System (INIS)

    Wallbrink, Peter J.

    2004-01-01

    In this paper, the contributions from the three major erosion sources in the catchments of Moreton Bay are quantified, specifically for the 137 Cs and 226 Ra were measured on the <10 μm fraction of eroding soils from these areas and then compared to concentrations on the same size fraction on deposited sediments within the rivers. A mixing model was then used to calculate the contributions from the different sources to the sediments. The contributions in the Brisbane and Logan catchments were found to be subsoil erosion (∼66±10%); sheet erosion from cultivated lands 33±10% and sheet erosion of uncultivated land 1±10%. Surface and subsoil erosion contributions from the coastal catchments were found to be variable

  14. A comparative study of seasonal variation of 137CS concentration in mangroves and sediment around Mumbai Harbour Bay

    International Nuclear Information System (INIS)

    Dutta, Madhuparna; Raj, Sanu S.; Jha, S.K.; Tripathi, R.M.

    2016-01-01

    Mangroves are various large and extensive types of trees up to medium height and also shrubs, which belong to the genus Rhizophora, that grow in saline coastal sediment habitats in the tropics and subtropics mainly between latitudes 25 ° N and 25° S. Mangrove ecosystems play a key role in nutrient and metal cycling. Because of their variable physical and chemical properties. Mangroves can act as a sink or a source of heavy metals in coastal environments. The level of trace metal which accumulate in mangroves differ seasonally and spatially varying with saline environment that may affect uptake and distribution of metals in the plants. Hence the estimation of 137 Cs activity in samples of mangrove and the surrounding sediment collected round the year will give us pattern of seasonal uptake. The study was carried out in Mumbai Harbour Bay (MHB), to estimate the 137 Cs activity concentration in mangrove leaves and the surrounding sediment and to compare the two

  15. Chemical composition of sediments from White Sea, Russian Arctic

    Science.gov (United States)

    Gamza, Olga; Shevchenko, Vladimir; Novigatsky, Aleksandr

    2010-05-01

    The White Sea, the only Russian inland sea, is located on the north of outlying districts of the European part of Russia, belongs to Arctic Ocean. Area of water of sea occupies about 90 tousend square kilometers. The sea can be divided into some general parts: neck, funnel, basin and 4 Bays: Dvina Bay, Kandalaksha Bay, Mezen Bay and Onega Bay. The purpose of this work was geochemical mapping of the surface sediments of this area. The main tasks were: compilation data base of element composition of the surface sediments, geochemical mapping of each element, research of the anormal concentration of elements on the surface. To detect the content of chemical elements several methods were used: atomic absorption spectrometry (P.P. Shirshov Institute of Oceanology); neutron activation analysis (Vernadsky Institute of Geochemistry and Analytical Chemistry), total and organic carbon analysis, photometric method to detection Si, Al, P (P.P. Shirshov Institute of Oceanology). Bulk composition is one of the fundamental characteristics of sediments and bottom deposites of modern basins. Coarse-grained sediments with portion of pelitic component 80%). Character of elements distribution correlates with facial distribution of sediments from White Sea. According to litologic description, bottom surface of Dvina Bay is practically everywhere covered by layer of fine-grained sand. In the border area between Dvina Bay and White Sea basin on terraced subwater slope aleurite politic silts are abundant. They tend to exhange down the slope to clay silts. In Onega Bay fractions of non-deposition are observed. They are characterized by wide spread of thin blanket poorgraded sediments, which are likely to be relic. Relief of Kandalakscha Bay bottom is presented as alternation of abyssal fosses (near 300 m) with silles and elevations (roof owning to diagenetic contraction. Authors thank academic Lisitsyn for encourage, Andrey Apletalin for valuable help, and everybody, who helped in field

  16. The Holocene History of Placentia Bay, Newfoundland

    DEFF Research Database (Denmark)

    Sheldon, Christina; Seidenkrantz, Marit-Solveig; Reynisson, Njall

    2013-01-01

    Marine sediments analyzed from cores taken in Placentia Bay, Newfoundland, located in the Labrador Sea, captured oceanographic and climatic changes from the end of the Younger Dryas through the Holocene. Placentia Bay is an ideal site to capture changes in both the south-flowing Labrador Current ...

  17. Mobile Bay turbidity plume study

    Science.gov (United States)

    Crozier, G. F.

    1976-01-01

    Laboratory and field transmissometer studies on the effect of suspended particulate material upon the appearance of water are reported. Quantitative correlations were developed between remotely sensed image density, optical sea truth data, and actual sediment load. Evaluation of satellite image sea truth data for an offshore plume projects contours of transmissivity for two different tidal phases. Data clearly demonstrate the speed of change and movement of the optical plume for water patterns associated with the mouth of Mobile bay in which relatively clear Gulf of Mexico water enters the bay on the eastern side. Data show that wind stress in excess of 15 knots has a marked impact in producing suspended sediment loads.

  18. Alteration in Solid State Phosphorous With Depth in Sediments Along the Salinity Transition Zone of a Major Chesapeake Bay Tributary

    Science.gov (United States)

    Hartzell, J. L.; Jordan, T. E.

    2006-05-01

    Determining the fate of particulate phosphorus in estuaries is essential for addressing the widespread problem of estuarine eutrophication, and is key to understanding P cycling and developing accurate global P budgets. Prominent reservoirs of P in surficial sediments include particulate P associated with iron or organic C. However, the importance of these reservoirs changes with the decomposition of organic matter and the reduction of iron. Also, the importance of iron bound P may decrease with increasing salinity due to the formation of iron sulfides. To investigate estuarine P burial and its relationship to salinity, we collected sediment cores of one-meter depth along the salinity gradient of the Patuxent River estuary (Maryland, USA), a major tributary of Chesapeake Bay. The sediments were analyzed using a sequential sedimentary extraction procedure that quantifies five separate reservoirs of particulate P. Total phosphorus concentrations in freshwater sediments were significantly higher than those in more saline sediments at all depths. Conversely, porewater phosphate concentrations were significantly lower in freshwater sediments than in the more saline sediments. Total P in the saline sediment cores decreased with depth, correlating to a reduction in iron-bound P. However, we did not find a concurrent increase in authigenic apatite with depth. Our findings indicate that mechanisms controlling changes in P sorption to sediments change profoundly with salinity and may contribute to increased bioavailability of phosphates with increasing salinity.

  19. Benthic harpacticoid copepods of Jiaozhou Bay, Qingdao

    Science.gov (United States)

    Ma, Lin; Li, Xinzheng

    2017-09-01

    The species richness of benthic harpacticoid copepod fauna in Jiaozhou Bay, Qingdao, on the southern coast of Shandong Peninsula, has not been comprehensively studied. We present a preliminary inventory of species for this region based on material found in nine sediment samples collected from 2011 to 2012. Our list includes 15 species belonging to 15 genera in 9 families, the most speciose family was the Miraciidae Dana, 1846 (seven species); all other families were represented by single species only. Sediment characteristics and depth are determined to be important environmental determinants of harpacticoid distribution in this region. We briefly detail the known distributions of species and provide a key to facilitate their identification. Both harpacticoid species richness and the species/genus ratio in Jiaozhou Bay are lower than in Bohai Gulf and Gwangyang Bay. The poor knowledge of the distribution of benthic harpacticoids, in addition to low sampling effort in Jiaozhou Bay, likely contribute to low species richness.

  20. Northeast Guanabara Bay and coastal plain Holocene sedimentary evolution (Brazil: A contribution

    Directory of Open Access Journals (Sweden)

    Rodrigo Coutinho Abuchacra

    2017-02-01

    Full Text Available Sedimentological and radiocarbon investigations are part of an ongoing research on the Bay-head delta of northeast Guanabara Bay, Rio de Janeiro State. Sediment accumulation indicates that the Holocene infill of the bay-head delta started around 8.2 kyr BP and was not in pace with the eustatic sea-level rise. Sediment accumulation was faster during the transgressive phase (0.56 cm.yr-1. However, during the regressive phase, progradation driven by base-level fall was predominant over vertical sediment accumulation (0.02 cm.yr-1. Based on coring, three sedimentary units were defined: fluvial sands (U1, estuarine deposits (U2 and fluvial mud (U3.

  1. Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for simulation of geomorphic evolution

    Science.gov (United States)

    Ganju, N.K.; Schoellhamer, D.H.

    2009-01-01

    Modeling geomorphic evolution in estuaries is necessary to model the fate of legacy contaminants in the bed sediment and the effect of climate change, watershed alterations, sea level rise, construction projects, and restoration efforts. Coupled hydrodynamic and sediment transport models used for this purpose typically are calibrated to water level, currents, and/or suspended-sediment concentrations. However, small errors in these tidal-timescale models can accumulate to cause major errors in geomorphic evolution, which may not be obvious. Here we present an intermediate step towards simulating decadal-timescale geomorphic change: calibration to estimated sediment fluxes (mass/time) at two cross-sections within an estuary. Accurate representation of sediment fluxes gives confidence in representation of sediment supply to and from the estuary during those periods. Several years of sediment flux data are available for the landward and seaward boundaries of Suisun Bay, California, the landward-most embayment of San Francisco Bay. Sediment flux observations suggest that episodic freshwater flows export sediment from Suisun Bay, while gravitational circulation during the dry season imports sediment from seaward sources. The Regional Oceanic Modeling System (ROMS), a three-dimensional coupled hydrodynamic/sediment transport model, was adapted for Suisun Bay, for the purposes of hindcasting 19th and 20th century bathymetric change, and simulating geomorphic response to sea level rise and climatic variability in the 21st century. The sediment transport parameters were calibrated using the sediment flux data from 1997 (a relatively wet year) and 2004 (a relatively dry year). The remaining years of data (1998, 2002, 2003) were used for validation. The model represents the inter-annual and annual sediment flux variability, while net sediment import/export is accurately modeled for three of the five years. The use of sediment flux data for calibrating an estuarine geomorphic

  2. Empirical models based on the universal soil loss equation fail to predict sediment discharges from Chesapeake Bay catchments.

    Science.gov (United States)

    Boomer, Kathleen B; Weller, Donald E; Jordan, Thomas E

    2008-01-01

    The Universal Soil Loss Equation (USLE) and its derivatives are widely used for identifying watersheds with a high potential for degrading stream water quality. We compared sediment yields estimated from regional application of the USLE, the automated revised RUSLE2, and five sediment delivery ratio algorithms to measured annual average sediment delivery in 78 catchments of the Chesapeake Bay watershed. We did the same comparisons for another 23 catchments monitored by the USGS. Predictions exceeded observed sediment yields by more than 100% and were highly correlated with USLE erosion predictions (Pearson r range, 0.73-0.92; p USLE estimates (r = 0.87; p USLE model did not change the results. In ranked comparisons between observed and predicted sediment yields, the models failed to identify catchments with higher yields (r range, -0.28-0.00; p > 0.14). In a multiple regression analysis, soil erodibility, log (stream flow), basin shape (topographic relief ratio), the square-root transformed proportion of forest, and occurrence in the Appalachian Plateau province explained 55% of the observed variance in measured suspended sediment loads, but the model performed poorly (r(2) = 0.06) at predicting loads in the 23 USGS watersheds not used in fitting the model. The use of USLE or multiple regression models to predict sediment yields is not advisable despite their present widespread application. Integrated watershed models based on the USLE may also be unsuitable for making management decisions.

  3. Dinoflagellate cyst abundance is positively correlated to sediment organic carbon in Sydney Harbour and Botany Bay, NSW, Australia.

    Science.gov (United States)

    Tian, Chang; Doblin, Martina A; Dafforn, Katherine A; Johnston, Emma L; Pei, Haiyan; Hu, Wenrong

    2018-02-01

    There is growing public concern about the global expansion of harmful algal bloom species (HABs), with dinoflagellate microalgae comprising the major portion of the harmful taxa. These motile, unicellular organisms have a lifecycle involving sexual reproduction and resting cyst formation whereby cysts can germinate from sediments and 'seed' planktonic populations. Thus, investigation of dinoflagellate cyst (dinocyst) distribution in sediments can provide significant insights into HAB dynamics and contribute to indices of habitat quality. Species composition and abundance of dinocysts in relation to sediment characteristics were studied at 18 stations in two densely populated temperate Australian estuaries, Sydney Harbour (Parramatta River/Port Jackson; PS) and Botany Bay (including Georges River; GB). Eighteen dinocyst taxa were identified, dominated by Protoceratium reticulatum and Gonyaulax sp.1 in the PS estuary, together with Archaeperidinium minutum and Gonyaulax sp.1 in the GB estuary. Cysts of Alexandrium catenella, which is one of the causative species of paralytic shellfish poisoning (PSP), were also detected in both estuaries. Out of the measured sediment characteristics (TOC, Cd, Cr, Cu, Fe, Pb, Mn, Ni, Zn and polycyclic aromatic hydrocarbons), TOC was the parameter explaining most of the variation in dinocyst assemblages and was positively correlated to most of the heavy metals. Given the significant relationship between sediment TOC and dinocyst abundance and heavy metal concentrations, this study suggests that sediment TOC could be broadly used in risk management for potential development of algal blooms and sediment contamination in these estuaries.

  4. Studies on seasonal pollution of heavy metals in water, sediment, fish and oyster from the Meiliang Bay of Taihu Lake in China.

    Science.gov (United States)

    Rajeshkumar, Sivakumar; Liu, Yang; Zhang, Xiangyang; Ravikumar, Boopalan; Bai, Ge; Li, Xiaoyu

    2018-01-01

    The present study, seasonal pollution of heavy metals (Pb, Cd, Cr and Cu) in water, sediment, tissues of fish Carassius carassius and oyster Crassostrea gigas were determined at seven sampling sites from Meiliang Bay, Taihu Lake during one year calendar, 2016. The total heavy metal concentrations in water samples were higher in winter and summer than in spring and autumn season, whereas in sediment they were higher in winter and summer seasons, respectively. The trend of metal mean contents found in the fish and oyster were in decreasing order of Pb > Cu > Cr > Cd and Pb > Cu > Cr > Cd, respectively. The tissues of fish and oyster captured during winter and summer accumulated a higher significant different amount of metals relative to other season, which was attributed to a higher influx of agricultural waste, sewage and sludge by heavy rainfall and floods. In addition, the pollution load index (PLI) values were above one (>1), indicating an advanced decline of the sediment quality, and contamination factor (CF) confirmed that the sediment samples were moderate to high contamination by Pb and Cr. Thus, comparative studies with seasonal pollution of heavy metals in Meiliang Bay of Lake Taihu regions indicate considerable heavy metal enrichment in water, sediments as well as in various organs of fish and oyster. Finally, our results indicated that the metal concentration values increased statistically significant different related to season (p heavy metal stress biomarkers in fish along with seasonal variations may serve as a convenient approach during pollution bio-monitoring programme. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Holocene depocenter migration and sediment accumulation in Delaware Bay: A submerging marginal marine sedimentary basin

    Science.gov (United States)

    Fletcher, C. H.; Knebel, H.J.; Kraft, J.C.

    1992-01-01

    The Holocene transgression of the Delaware Bay estuary and adjacent Atlantic coast results from the combined effect of regional crustal subsidence and eustasy. Together, the estuary and ocean coast constitute a small sedimentary basin whose principal depocenter has migrated with the transgression. A millenial time series of isopach and paleogeographic reconstructions for the migrating depocenter outlines the basin-wide pattern of sediment distribution and accumulation. Upland sediments entering the basin through the estuarine turbidity maximum accumulate in tidal wetland or open water sedimentary environments. Wind-wave activity at the edge of the tidal wetlands erodes the aggraded Holocene section and builds migrating washover barriers. Along the Atlantic and estuary coasts of Delaware, the area of the upland environment decreases from 2.0 billion m2 to 730 million m2 during the transgression. The area of the tidal wetland environment increases from 140 million to 270 million m2, and due to the widening of the estuary the area of open water increases from 190 million to 1.21 billion m2. Gross uncorrected rates of sediment accumulation for the tidal wetlands decrease from 0.64 mm/yr at 6 ka to 0.48 mm/yr at 1 ka. In the open water environments uncorrected rates decrease from 0.50 mm/yr to 0.04 mm/yr over the same period. We also present data on total sediment volumes within the tidal wetland and open water environments at specific intervals during the Holocene. 

  6. Amphipod and Sea Urchin tests to assess the toxicity of Mediterranean sediments: the case of Portmán Bay

    Directory of Open Access Journals (Sweden)

    A. Cesar

    2004-04-01

    Full Text Available The sediment formed by the tailings of an abandoned mine, which discharged into Portmán Bay, Murcia, SE-Spain, was tested to establish a possible gradient of heavy metals. The results were compared with tolerance limits of what was calculated from control sites. Whole sediment toxicity tests were performed on two amphipod species, Gammarus aequicauda and Microdeutopus gryllotalpa, while sediment-water interface and porewater toxicity tests were performed on three sea urchins species, Arbacia lixula, Paracentrotus lividus and Sphaerechinus granularis. The sensitivity of these marine organisms was evaluated by exposure tests using the reference substances: ammonium chloride (NH4Cl, cadmium chloride (CdCl2, potassium dichromate (K2Cr2O7, sodium dodecyl sulfate (C12H25NaO4S and zinc sulfate (ZnSO4. The concentration of heavy metals decreased along the pollution gradient. Amphipod 10 day acute toxicity tests clearly demonstrated the gradient of toxicity. The sediment-water interface tests conducted with sea urchins also pointed to a pollution gradient and were more sensitive than the tests involving amphipods.

  7. Distribution of biologic, anthropogenic, and volcanic constituents as a proxy for sediment transport in the San Francisco Bay Coastal System

    Science.gov (United States)

    McGann, Mary; Erikson, Li H.; Wan, Elmira; Powell, Charles; Maddocks, Rosalie F.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Although conventional sediment parameters (mean grain size, sorting, and skewness) and provenance have typically been used to infer sediment transport pathways, most freshwater, brackish, and marine environments are also characterized by abundant sediment constituents of biological, and possibly anthropogenic and volcanic, origin that can provide additional insight into local sedimentary processes. The biota will be spatially distributed according to its response to environmental parameters such as water temperature, salinity, dissolved oxygen, organic carbon content, grain size, and intensity of currents and tidal flow, whereas the presence of anthropogenic and volcanic constituents will reflect proximity to source areas and whether they are fluvially- or aerially-transported. Because each of these constituents have a unique environmental signature, they are a more precise proxy for that source area than the conventional sedimentary process indicators. This San Francisco Bay Coastal System study demonstrates that by applying a multi-proxy approach, the primary sites of sediment transport can be identified. Many of these sites are far from where the constituents originated, showing that sediment transport is widespread in the region. Although not often used, identifying and interpreting the distribution of naturally-occurring and allochthonous biologic, anthropogenic, and volcanic sediment constituents is a powerful tool to aid in the investigation of sediment transport pathways in other coastal systems.

  8. Abyssal sediment erosion from the Central Indian Basin: Evidence from radiochemical and radiolarian studies

    Digital Repository Service at National Institute of Oceanography (India)

    Banakar, V.K.; Gupta, S.M.; Padmavati, V.K.

    ) 167-173 167 Elsevier Science Publishers B.V., Amsterdam Letter Section Abyssal sediment erosion in the Central Indian Basin: Evidence from radiochemical and radiolarian studies V.K. Banakar, S.M. Gupta and V.K. Padmavathi National Institute... of Oceanography, Dona-Paula, Goa-403 004, India (Revision accepted September 17, 1990) ABSTRACT Banakar, V.K., Gupta, S.M. and Padmavathi, V.K., 1991. Abyssal sediment erosion from the Central Indian Basin: Evi- dence from radiochemical and radiolarian studies...

  9. Features of distribution and quality of organic matter in the bottom sediments of the Great Peter Bay (Sea of Japan)

    Science.gov (United States)

    Nesterova, Olga; Tregubova, Valentina; Semal, Victoria; Vasenev, Ivan

    2017-04-01

    The nature and distribution of organic carbon in marine waters depends on: 1) biological productivity and revenue of the autochthonous organic matter to the bottom; 2) sediment grain-size composition and conditions of dumping, which in turn depends of hydrothermic regime, topography, speed River mist and received major erosion products; 3) living conditions of the benthos (the quantity consumed of OM, gas regime of habitats, physiological capacity of heterotrophs). Autochthonous OM of phytoplankton plays a dominant role in the processes of formation of humus in aquatic conditions. Bottom sediments at different distance from the shoreline to depths from 0.5 up to 480 m of the Sea of Japan, which are formed in various conditions of facies, were selected as the objects of study. There is no clear relationships to the amount of organic matter in bottom sediments on the characteristics of the distribution and nature of living matter in the oceans and seas. This is because the process of sedimentation and fossilization of organic matter on the seabed and the ocean floor depends on many factors (currents, depth). Humus of studied bottom sediments in composition can be attributed mainly to the humic type. Nonhydrolyzing rest is 70-90%. This is characteristic of bottom sediments formed in facial types of small bays, internal coastal shelf bights and the underwater slope. At a fraction of the carbon of humic acids in organic matter, ranging from 4 to 80% of the amount of humic and fulvic acids. Fulvic acids content is much less. This is due to more favourable conservation situation of humic acids in precipitation with high content of organic matter, whereas fulvic acids in aquatic environments are more labile and almost not dumped. Despite the fact humic acids are not the most stable component (s), however, with increased content of humic acids, the mobility of organic matter and removing it from the bottom sediments are reduced. Internal shelf facies of the Great Peter Bay

  10. Holocene depositional history of a large glaciated estuary, Penobscot Bay, Maine

    Science.gov (United States)

    Knebel, H.J.

    1986-01-01

    Data from seismic-reflection profiles, sidescan sonar images, and sediment samples reveal the Holocene depositional history of the large (1100 km2) glaciated Penobscot Bay estuary of coastal Maine. Previous work has shown that the late Wisconsinan ice sheet retreated from the three main passages of the bay between 12,700 and 13,500 years ago and was accompanied by a marine transgression during which ice and sea were in contact. Isostatic recovery of the crust caused the bay to emerge during the immediate postglacial period, and relative sea level fell to at least -40 m sometime between 9000 and 11,500 years ago. During lowered sea level, the ancestral Penobscot River flowed across the subaerially exposed head of the bay and debouched into Middle Passage. Organic-matter-rich mud from the river was deposited rapidly in remnant, glacially scoured depressions in the lower reaches of Middle and West Passages behind a shallow (???20 m water depth) bedrock sill across the bay mouth. East Passage was isolated from the rest of the bay system and received only small amounts of locally derived fine-grained sediments. During the Holocene transgression that accompanied the eustatic rise of sea level, the locus of sedimentation shifted to the head of the bay. Here, heterogeneous fluvial deposits filled the ancestral valley of the Penobscot River as base level rose, and the migrating surf zone created a gently dipping erosional unconformity, marked by a thin (energy conditions and the waning influence of the Penobscot River at the head of the bay. In contrast, relatively thick (up to 25 m) silty clays accumulated within a subbottom trough in the western half of the bay head. This deposit apparently developed late in the transgression after sea level had reached -20 m and after the westward transport of fine-grained sediments from the Penobscot River had been established. During and since the late Holocene transgression of sea level, waves and currents have eroded, reworked, and

  11. Evaluation of the biodegradability of petroleum in microcosm systems by using mangrove sediments from Camamu Bay, Bahia, Brazil.

    Science.gov (United States)

    Santos, A C F; Rezende, R P; Brendel, M; Souza, S S; Gonçalves, A C S; Dias, J C T

    2014-03-24

    We investigated the biodegradability of oil in mangrove sediment from Camamu Bay and measured its effect on the bacterial community. Microcosms of mangrove sediment were contaminated with 0.1, 0.5, 1, 2, and 5% (w/v) oil, and the microbial activity was compared to that in uncontaminated sediment. The evolution of CO2 and gas chromatography showed the mineralization of oil compounds, which could reach 100%. Bacterial diversity was determined by polymerase chain reaction using a set of primers for the V3 and V6-V8 regions of 16S rDNA. The band profile obtained by denaturing gradient gel electrophoresis of the amplicons that were obtained for the V3 region showed a negative correlation between band number and oil concentration, whereas that of the V6-V8 region showed a positive correlation between band numbers and oil concentration. The latter also gave similar results for microcosms that were contaminated with 2 and 5% oil. These results demonstrate the mangrove sediment's capacity to recover from oil contamination (in vitro) and suggest that native mangrove microorganisms contain enzymes necessary for the catabolism of oil.

  12. Reconnaissance of chemical and physical characteristics of selected bottom sediments of the Caloosahatchee River and estuary, tributaries, and contiguous bays, Lee County, Florida, July 20-30, 1998

    Science.gov (United States)

    Fernandez, Mario; Marot, M.E.; Holmes, C.W.

    1999-01-01

    This report summarizes a reconnaissance study, conducted July 20-30, 1998, of chemical and physical characteristics of recently deposited bottom sediments in the Caloosahatchee River and Estuary. Recently deposited sediments were identified using an isotopic chronometer, Beryllium-7 (7Be), a short-lived radioisotope. Fifty-nine sites were sampled in an area that encompasses the Caloosahatchee River (River) about three miles upstream from the Franklin Lock (S-79), the entire tidally affected length of the river (estuary), and the contiguous water bodies of Matlacha Pass, San Carlos Bay, Estero Bay, Tarpon Bay, and Pine Island Sound in Lee County, Florida. Bottom sediments were sampled for 7Be at 59 sites. From the results of the 7Be analysis, 30 sites were selected for physical and chemical analysis. Sediments were analyzed for particle size, total organic carbon (TOC), trace elements, and toxic organic compounds, using semiquantitative methods for trace elements and organic compounds. The semiquantitative scans of trace elements indicated that cadmium, copper, lead, and zinc concentrations, when normalized to aluminum, were above the natural background range at 24 of 30 sites. Particle size and TOC were used to characterize sediment deposition patterns and organic content. Pesticides, polychlorinated biphenyls (PCBs), and carcinogenic polycyclic aromatic hydrocarbons (CaPAHs) were determined at 30 sites using immunoassay analysis. The semiquantitative immunoassay analyses of toxic organic compounds indicated that all of the samples contained DDT, cyclodienes as chlordane (pesticides), and CaPAHs. PCBs were not detected. Based on analyses of the 30 sites, sediments at 10 of these sites were analyzed for selected trace elements and toxic organic compounds, including pesticides, PCBs, and PAHs, using quantitative laboratory procedures. No arsenic or cadmium was detected. Zinc was detected at two sites with concentrations greater than the lower limit of the range of

  13. Coastal circulation and sediment dynamics in Pelekane and Kawaihae Bays, Hawaii--measurements of waves, currents, temperature, salinity, turbidity, and geochronology: November 2010--March 2011

    Science.gov (United States)

    Storlazzi, Curt D.; Field, Michael E.; Presto, M. Katherine; Swarzenski, Peter W.; Logan, Joshua B.; Reiss, Thomas E.; Elfers, Timothy C.; Cochran, Susan A.; Torresan, Michael E.; Chezar, Hank

    2012-01-01

    Coral reef communities on the Island of Hawaii have been heavily affected by the construction of Kawaihae Harbor in the 1950s and by subsequent changes in land use in the adjacent watershed. Sedimentation and other forms of land-based pollution have led to declines in water quality and coral reef health over the past two decades (Tissot, 1998). Erosion mitigation efforts are underway on land, and there is a need to evaluate the impact of these actions on the adjacent coastal ecosystem. The Kohala Center and Kohala Watershed Partnership was awarded $2.69 million from the National Oceanographic and Atmospheric Administration’s (NOAA) Restoration Center as part of the American Recovery and Reinvestment Act of 2009 to stabilize soil and improve land-use practices in the Pelekane Bay watershed. The grant allowed the Kohala Watershed Partnership to implement various upland watershed management activities to reduce land-based sources of pollution into Pelekane Bay. However, a number of questions must be answered in order to: (1) evaluate the effectiveness of the terrestrial watershed remediation efforts; (2) understand the potential of the local marine ecosystem to recover; and (3) understand the potential threat that existing mud deposits in the bay pose to adjacent, relatively pristine coral reef ecosystems. The goal of this experiment was to help address these questions and establish a framework to evaluate the success of the Kohala Watershed Partnership restoration efforts. This research program will also provide resource managers with information relevant to other watershed restoration efforts currently being planned in neighboring watersheds. This project involved an interdisciplinary team of coral reef biologists from the University of Hawaii Coral Reef Assessment and Monitoring Program, who focused on the impact of sedimentation on the biota of Pelekane Bay, and a team of geologists and oceanographers from the U.S. Geological Survey (USGS), who focused on the

  14. Annual sediment flux estimates in a tidal strait using surrogate measurements

    Science.gov (United States)

    Ganju, N.K.; Schoellhamer, D.H.

    2006-01-01

    Annual suspended-sediment flux estimates through Carquinez Strait (the seaward boundary of Suisun Bay, California) are provided based on surrogate measurements for advective, dispersive, and Stokes drift flux. The surrogates are landward watershed discharge, suspended-sediment concentration at one location in the Strait, and the longitudinal salinity gradient. The first two surrogates substitute for tidally averaged discharge and velocity-weighted suspended-sediment concentration in the Strait, thereby providing advective flux estimates, while Stokes drift is estimated with suspended-sediment concentration alone. Dispersive flux is estimated using the product of longitudinal salinity gradient and the root-mean-square value of velocity-weighted suspended-sediment concentration as an added surrogate variable. Cross-sectional measurements validated the use of surrogates during the monitoring period. During high freshwater flow advective and dispersive flux were in the seaward direction, while landward dispersive flux dominated and advective flux approached zero during low freshwater flow. Stokes drift flux was consistently in the landward direction. Wetter than average years led to net export from Suisun Bay, while dry years led to net sediment import. Relatively low watershed sediment fluxes to Suisun Bay contribute to net export during the wet season, while gravitational circulation in Carquinez Strait and higher suspended-sediment concentrations in San Pablo Bay (seaward end of Carquinez Strait) are responsible for the net import of sediment during the dry season. Annual predictions of suspended-sediment fluxes, using these methods, will allow for a sediment budget for Suisun Bay, which has implications for marsh restoration and nutrient/contaminant transport. These methods also provide a general framework for estimating sediment fluxes in estuarine environments, where temporal and spatial variability of transport are large. ?? 2006 Elsevier Ltd. All rights

  15. Spatiotemporal appraisal of TBT contamination and imposex along a tropical bay (Todos os Santos Bay, Brazil).

    Science.gov (United States)

    Artifon, Vanda; Castro, Ítalo Braga; Fillmann, Gilberto

    2016-08-01

    A spatiotemporal evaluation of butyltin contamination was performed between 2010 and 2012 along Todos os Santos Bay (Northeast Brazil) using surface sediments, bivalve tissues (Anomalocardia brasiliana and Mytella guyanensis), and imposex occurrence (Stramonita rustica). The spatial study detected high tributyltin (TBT) levels (maximum values of 262 ng Sn g (-1) - 21,833 ng Sn g(-1) of total organic carbon - for surface sediments and 421 ng Sn g(-1) for bivalve tissues) in the innermost part of the bay. The TBT levels detected in M. guyanensis tissues might cause human health risk since local population consumes these organisms. These high concentrations observed in the bivalves might result in ingestions higher than the safe limits established by European Food Safety Authority (250 ng TBT kg(-1) day(-1)). Considering the temporal evaluation, no difference (p > 0.05) was observed between TBT concentrations in sediments obtained during the two sampling campaigns (2010/2011 and 2012). However, the increasing predominance of TBT metabolites (butyltin degradation index (BDI) >1) in more recent sediments indicates further degradation of old TBT inputs. In spite of that, recent inputs are still evident at this region. Nevertheless, a reduction of imposex parameters in S. rustica over the last decade suggests an overall decline in the TBT contamination, at least in the outermost and possible less impacted region of the bay. The TBT contamination is probably reducing due to the national and international legislative restrictions on the use of TBT as antifouling biocide. The contamination levels, however, are still relevant especially in the inner part of Todos os Santos Bay since they are above those that are likely to cause toxicity to the biota.

  16. How can climate change and engineered water conveyance affect sediment dynamics in the San Francisco Bay-Delta system?

    Science.gov (United States)

    Achete, Fernanda; Van der Wegen, Mick; Roelvink, Jan Adriaan; Jaffe, Bruce E.

    2017-01-01

    Suspended sediment concentration is an important estuarine health indicator. Estuarine ecosystems rely on the maintenance of habitat conditions, which are changing due to direct human impact and climate change. This study aims to evaluate the impact of climate change relative to engineering measures on estuarine fine sediment dynamics and sediment budgets. We use the highly engineered San Francisco Bay-Delta system as a case study. We apply a process-based modeling approach (Delft3D-FM) to assess the changes in hydrodynamics and sediment dynamics resulting from climate change and engineering scenarios. The scenarios consider a direct human impact (shift in water pumping location), climate change (sea level rise and suspended sediment concentration decrease), and abrupt disasters (island flooding, possibly as the results of an earthquake). Levee failure has the largest impact on the hydrodynamics of the system. Reduction in sediment input from the watershed has the greatest impact on turbidity levels, which are key to primary production and define habitat conditions for endemic species. Sea level rise leads to more sediment suspension and a net sediment export if little room for accommodation is left in the system due to continuous engineering works. Mitigation measures like levee reinforcement are effective for addressing direct human impacts, but less effective for a persistent, widespread, and increasing threat like sea level rise. Progressive adaptive mitigation measures to the changes in sediment and flow dynamics resulting from sea level rise may be a more effective strategy. Our approach shows that a validated process-based model is a useful tool to address long-term (decades to centuries) changes in sediment dynamics in highly engineered estuarine systems. In addition, our modeling approach provides a useful basis for long-term, process-based studies addressing ecosystem dynamics and health.

  17. Climate variability during the Medieval Climate Anomaly and Little Ice Age based on ostracod faunas and shell geochemistry from Biscayne Bay, Florida: Chapter 14

    Science.gov (United States)

    Cronin, Thomas M.; Wingard, G. Lynn; Dwyer, Gary S.; Swart, Peter K.; Willard, Debra A.; Albietz, Jessica

    2012-01-01

    An 800-year-long environmental history of Biscayne Bay, Florida, is reconstructed from ostracod faunal and shell geochemical (oxygen, carbon isotopes, Mg/Ca ratios) studies of sediment cores from three mudbanks in the central and southern parts of the bay. Using calibrations derived from analyses of modern Biscayne and Florida Bay ostracods, palaeosalinity oscillations associated with changes in precipitation were identified. These oscillations reflect multidecadal- and centennial-scale climate variability associated with the Atlantic Multidecadal Oscillation during the late Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA). Evidence suggests wetter regional climate during the MCA and drier conditions during the LIA. In addition, twentieth century anthropogenic modifications to Everglades hydrology influenced bay circulation and/or processes controlling carbon isotopic composition.

  18. Antibacterial agents and heavy metal resistance in Gram-negative bacteria isolated from seawater, shrimp and sediment in Iskenderun Bay, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Matyar, Fatih [Cukurova University, Faculty of Education, Department of Science and Technology Education, 01330 Balcali, Adana (Turkey)], E-mail: fmatyar@cu.edu.tr; Kaya, Aysenur; Dincer, Sadik [Cukurova University, Faculty of Science and Letters, Department of Biology, 01330 Balcali, Adana (Turkey)

    2008-12-15

    The aim of the present study was to determine the level of antibiotic resistance patterns and distribution of heavy metal resistance of bacterial isolates from seawater, sediment and shrimps, and to determine if there is a relationship between antibiotic and heavy metal resistance. We undertook studies in 2007 in the industrially polluted Iskenderun Bay, on the south coast of Turkey. The resistance of 236 Gram-negative bacterial isolates (49 from seawater, 90 from sediment and 97 from shrimp) to 16 different antibiotics, and to 5 heavy metals, was investigated by agar diffusion and agar dilution methods, respectively. A total of 31 species of bacteria were isolated: the most common strains isolated from all samples were Escherichia coli (11.4%), Aeromonas hydrophila (9.7%) and Stenotrophomonas maltophilia (9.3%). There was a high incidence of resistance to ampicillin (93.2%), streptomycin (90.2%) and cefazolin (81.3%), and a low incidence of resistance to imipenem (16.5%), meropenem (13.9%) and cefepime (8.0%). Some 56.8% of all bacteria isolated from seawater, sediment and shrimp were resistant to 7 or more antibiotics. Most isolates showed tolerance to different concentrations of heavy metals, and minimal inhibition concentrations ranged from 12.5 {mu}g/ml to > 3200 {mu}g/ml. The bacteria from seawater, sediment and shrimp showed high resistance to cadmium of 69.4%, 88.9%, and 81.1% respectively, and low resistance to manganese of 2%, 6.7% and 11.3% respectively. The seawater and sediment isolates which were metal resistant also showed a high resistance to three antibiotics: streptomycin, ampicillin and trimethoprim-sulphamethoxazole. In contrast, the shrimp isolates which were metal resistant were resistant to four antibiotics: cefazolin, nitrofurantoin, cefuroxime and ampicillin. Our results show that Iskenderun Bay has a significant proportion of antibiotic and heavy metal resistant Gram-negative bacteria, and these bacteria constitute a potential risk for

  19. Antibacterial agents and heavy metal resistance in Gram-negative bacteria isolated from seawater, shrimp and sediment in Iskenderun Bay, Turkey

    International Nuclear Information System (INIS)

    Matyar, Fatih; Kaya, Aysenur; Dincer, Sadik

    2008-01-01

    The aim of the present study was to determine the level of antibiotic resistance patterns and distribution of heavy metal resistance of bacterial isolates from seawater, sediment and shrimps, and to determine if there is a relationship between antibiotic and heavy metal resistance. We undertook studies in 2007 in the industrially polluted Iskenderun Bay, on the south coast of Turkey. The resistance of 236 Gram-negative bacterial isolates (49 from seawater, 90 from sediment and 97 from shrimp) to 16 different antibiotics, and to 5 heavy metals, was investigated by agar diffusion and agar dilution methods, respectively. A total of 31 species of bacteria were isolated: the most common strains isolated from all samples were Escherichia coli (11.4%), Aeromonas hydrophila (9.7%) and Stenotrophomonas maltophilia (9.3%). There was a high incidence of resistance to ampicillin (93.2%), streptomycin (90.2%) and cefazolin (81.3%), and a low incidence of resistance to imipenem (16.5%), meropenem (13.9%) and cefepime (8.0%). Some 56.8% of all bacteria isolated from seawater, sediment and shrimp were resistant to 7 or more antibiotics. Most isolates showed tolerance to different concentrations of heavy metals, and minimal inhibition concentrations ranged from 12.5 μg/ml to > 3200 μg/ml. The bacteria from seawater, sediment and shrimp showed high resistance to cadmium of 69.4%, 88.9%, and 81.1% respectively, and low resistance to manganese of 2%, 6.7% and 11.3% respectively. The seawater and sediment isolates which were metal resistant also showed a high resistance to three antibiotics: streptomycin, ampicillin and trimethoprim-sulphamethoxazole. In contrast, the shrimp isolates which were metal resistant were resistant to four antibiotics: cefazolin, nitrofurantoin, cefuroxime and ampicillin. Our results show that Iskenderun Bay has a significant proportion of antibiotic and heavy metal resistant Gram-negative bacteria, and these bacteria constitute a potential risk for public

  20. Response of suspended sediment concentration to tidal dynamics at a site inside the mouth of an inlet: Jiaozhou Bay (China

    Directory of Open Access Journals (Sweden)

    S. L. Yang

    2004-01-01

    Full Text Available Observations of fair weather currents and suspended sediment concentrations (SSC were made using an acoustic Doppler current profiler and two YSI turbidity sensors over a neap to spring time cycle at a site near the inner mouth of a semi-enclosed mesotidal-macrotidal embayment (Jiaozhou Bay to examine the influence of tidal dynamics on concentration and transport of suspended sediment. During the investigation, SSC varied from about 3 to 16 mg L–1 at the surface and about 6 to 40 mg L–1 close to the bed, while the current velocity reached 79 cm s–1 at the surface and 61 cm s–1 near the bed. SSC was tidally cyclic. The near-bed instantaneous SSC was closely related to current velocity with almost no time lag, indicating that the variability of SSC was governed by current-induced settling/resuspension. At the surface, however, instantaneous SSC was poorly related to instantaneous current velocity because the peak SSC tended to occur around ebb slack water. This suggests that the surface SSC was controlled by horizontal advection from landward higher concentration areas. Both at the surface and near the bed, on the other hand, tidally-averaged SSC was well correlated to tidal range and current speed. Current velocity and SSC were flood-dominated for all the tides investigated, which resulted in significant landward residual suspended sediment transport at the study site. The observed flood dominance was mainly attributed to the location of the study site on the landward side of the bay’s inlet where flow separation is favoured during flood tide. It was concluded that tides are the dominant hydrodynamic component controlling the variability of SSC during fair weather at the study area. Keywords: sediment, concentration, suspension, advection, currents, shoalling effect, Jiaozhou Bay, China

  1. Contaminant profiles for surface water, sediment, flora and fauna associated with the mangrove fringe along middle and lower eastern Tampa Bay.

    Science.gov (United States)

    Lewis, M A; Russell, M J

    2015-06-15

    Contaminant concentrations are reported for surface water, sediment, flora and fauna collected during 2010-2011 from the mangrove fringe along eastern Tampa Bay, Florida. Concentrations of trace metals, chlorinated pesticides, atrazine, total polycyclic aromatic hydrocarbons, and polychlorinated biphenyls were species-, chemical- and location-specific. Contaminants in sediments did not exceed proposed individual sediment quality guidelines. Most sediment quality assessment quotients were less than one indicating the likelihood of no inhibitory effect based on chemical measurements alone. Faunal species typically contained more contaminants than plant species; seagrass usually contained more chemicals than mangroves. Bioconcentration factors for marine angiosperms were usually less than 10 and ranged between 1 and 31. Mercury concentrations (ppm) in blue crabs and fish did not exceed the U.S. Environmental Protection Agency fish tissue criterion of 0.3 and the U.S. Food and Drug Administration action level of 1.0. In contrast, total mercury concentrations in faunal species often exceeded guideline values for wildlife consumers of aquatic biota. Published by Elsevier Ltd.

  2. Comparative account of macrofouling ecology at Vijaydurg Harbor and Musakazi-Jaitapur Bay, central western coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sawant, S.S.; Wagh, A.B.

    The extent and the nature of fouling were studied on mild steel, aluminum, and stainless steel panels at the Vijaydurg Harbor and Musakazi-Jaitapur Bay on the central western coast of India. In addition, cathodically protected and unprotected panels...

  3. The influence of seagrass on shell layers and Florida Bay mudbanks

    Science.gov (United States)

    Prager, E.J.; Halley, R.B.

    1999-01-01

    Aerial photography indicates that sometime since the early 1970's, an emergent ridge of shell debris developed on a mudbank north of Calusa Key in Florida Bay. Coarse shell deposits on and within the Bay's shallow mudbanks are believed to be the product of transport during major storm events and subsequent winnowing. However, shell material from the ridge contains nuclear bomb 14C, supporting formation within the past 30 years and the last major hurricanes to influence Florida Bay were Donna and Betsy (1960 and 1965). Results from this study suggest that the Calusa ridge and other coarse shell deposits in Florida Bay can result from, 1) periodic seagrass mortality and wave-induced transport during frequent winter cold fronts and/or 2) mollusc blooms and subsequent burial. A survey of bottom types indicates that dense to intermediate beds of seagrass, mainly Thalassia testudinum (turtle grass), occur within the shallow basins of western Florida Bay and along the margins of Bay mudbanks. Wave measurements and modeling indicate that Thalassia along mudbank margins can reduce incoming wave-energy by over 80%. Seagrass beds also host particularly dense populations of molluscs from periodic 'blooms' and are believed to be the major source of coarse sediments in the Bay. Thus, if bank-edge seagrass dies, sediments, including shell debris, become exposed and subject to greatly increased wave energy. Modeling indicates that winds typical of winter cold fronts in South Florida can produce near-bottom velocities and shear stress at a grass-free bank edge which are sufficient to transport coarse carbonate grains. Shell layers found at depth in mudbank cores can also be explained by previous episodes of sediment accretion over mollusc-rich seagrass beds or grass bed mortality at the edge of a mudbank and shell transport during cold front passage. The latter implies that mortality of marginal seagrass beds has occurred throughout the history of Florida Bay and that the

  4. Distribution of natural and anthropogenic radionuclides in surficial sediments of Jakarta bay

    International Nuclear Information System (INIS)

    Ali Arman Lubis

    2006-01-01

    he concentration and distribution of natural and anthropogenic radionuclide in surficial sediments of Jakarta Bay were investigated with the aim of evaluating its level and environmental radioactivity. Sediments were sampled in 30 locations using Smith-McIntyre Grab sampler. Sediments were dried, homogenized and sealed for 1 month for equilibration and for the detection, analysis and data acquisition, a high purity germanium (HPGe) detector coupled with a high resolution multichannel analyzer (MCA) was used. Additionally, the grain sizes were analyzed by means of hydrometer. The result shows that the specific activity of 238 U, 226 Ra, 232 Th, 40 K and 137 Cs range from 6.71±1.01 Bq/kg to 28.63±4.29 Bq/kg, 6.46±0.97 Bq/kg to 28.21±4.23 Bq/kg, 16.62±2.49 Bq/kg to 40.46±6.07 Bq/kg, 115.80±12.16 Bq/kg to 358.69±30.49 Bq/kg, and 0.03±0.01 Bq/kg to 1.99±0.34 Bq/kg with the average value are 12.83±2.11 Bq/kg, 12.03±1.98 Bq/kg, 26.55±4.36 Bq/kg, 235.55±19.37 Bq/kg, and 0.77±0.13 Bq/kg, respectively. It shows that the activity of radionuclides in the research area are in natural level and the variation may be influenced by the grain size distribution in the sample. The absorbed dose rate and radium equivalent of gamma radiation was estimated to be 32.06±7.72 nano Grey/h and 68.14±11.20 Bq/kg, respectively. (author)

  5. The effect of semi-permanent eddies on the distribution of mesozooplankton in the central Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, V.

    Five locations in the central Bay of Bengal (BoB) along a longitudinal transect at 88E were sampled during the Fall Intermonsoon, 2002 for mesozooplankton biomass, abundance, groups and copepod species composition. Stations at 9N and 18N had...

  6. Thatcher Bay, Washington, Nearshore Restoration Assessment

    Science.gov (United States)

    Breems, Joel; Wyllie-Echeverria, Sandy; Grossman, Eric E.; Elliott, Joel

    2009-01-01

    The San Juan Archipelago, located at the confluence of the Puget Sound, the Straits of Juan de Fuca in Washington State, and the Straits of Georgia, British Columbia, Canada, provides essential nearshore habitat for diverse salmonid, forage fish, and bird populations. With 408 miles of coastline, the San Juan Islands provide a significant portion of the available nearshore habitat for the greater Puget Sound and are an essential part of the regional efforts to restore Puget Sound (Puget Sound Shared Strategy 2005). The nearshore areas of the San Juan Islands provide a critical link between the terrestrial and marine environments. For this reason the focus on restoration and conservation of nearshore habitat in the San Juan Islands is of paramount importance. Wood-waste was a common by-product of historical lumber-milling operations. To date, relatively little attention has been given to the impact of historical lumber-milling operations in the San Juan Archipelago. Thatcher Bay, on Blakely Island, located near the east edge of the archipelago, is presented here as a case study on the restoration potential for a wood-waste contaminated nearshore area. Case study components include (1) a brief discussion of the history of milling operations. (2) an estimate of the location and amount of the current distribution of wood-waste at the site, (3) a preliminary examination of the impacts of wood-waste on benthic flora and fauna at the site, and (4) the presentation of several restoration alternatives for the site. The history of milling activity in Thatcher Bay began in 1879 with the construction of a mill in the southeastern part of the bay. Milling activity continued for more than 60 years, until the mill closed in 1942. Currently, the primary evidence of the historical milling operations is the presence of approximately 5,000 yd3 of wood-waste contaminated sediments. The distribution and thickness of residual wood-waste at the site was determined by using sediment

  7. Oceanographic characteristics of an impacted coastal bay: Baía de Guanabara, Rio de Janeiro, Brazil

    Science.gov (United States)

    Kjerfve, Björn; Ribeiro, Cesar H. A.; Dias, Gilberto T. M.; Filippo, Alessandro M.; Da Silva Quaresma, Valéria

    1997-11-01

    Baía de Guanabara is a 384 km 2 eutrophic coastal bay in Brazil, impacted by the polluted discharge from the Rio de Janeiro metropolitan area. The structurally controlled bay has a central channel with a depth of 30 m and a sandy bottom near the entrance, reflecting wave and tidal forcing. In contrast, the bay-averaged water depth is 5.7 m and the bottom sediments are mostly muds as a result of the Holocene transgression and rapid fluvial sedimentation, accelerated by channelization of rivers and deforestation. An extensive sand bank is located seaward of the bay entrance and a flood-oriented sand wave system indicates sand transport into the bay. The mean freshwater discharge measures 100±59 m 3 s -1 and is greatest in the rainy austral summer in December and January. Tides are mixed mainly semidiurnal with a range of 0.7 m, and peak spring tidal currents reach 0.5 m s -1 inside the bay and 1.6 m s -1 near the bay entrance. The passage of northward propagating polar fronts results in regular strong southwesterly winds and heavy wave forcing. The bay has mean salinities from 21.0 to 34.5‰ with an average of 29.5±4.8‰. The vertical salinity stratification, Δs/s, varies from 0.06 to 0.21 and is relatively weak and inversely proportional to rms tidal currents. The residual circulation is characterized by both gravitational circulation and transverse residual tidal circulation, measuring 800 and 400 m 3 s -1 respectively. The renewal time of 50% of the bay water volume is 11.4 days. Untreated sewage runoff enters the bay from the west, resulting in locally poor water quality, where the near-bottom mean dissolved oxygen measures only 3.1 mg 1 -1 and results in anoxic bottom muds. The worst water quality is indicated by average fecal coliform of 1140 counts ml -1 and excessive ammonia and phosphate loading. The average chlorophyll concentration in this region responds to the nutrient loading and exceeds 130 μg 1 -1 although 57 μg 1 -1 is the overall mean for

  8. Seasonal variation of early diagenesis and greenhouse gas production in coastal sediments of Cadiz Bay: Influence of anthropogenic activities

    Science.gov (United States)

    Burgos, Macarena; Ortega, Teodora; Bohórquez, Julio; Corzo, Alfonso; Rabouille, Christophe; Forja, Jesús M.

    2018-01-01

    Greenhouse gas production in coastal sediments is closely associated with the early diagenesis processes of organic matter and nutrients. Discharges from anthropogenic activities, particularly agriculture, fish farming and waste-water treatment plants supply large amounts of organic matter and inorganic nutrients that affect mineralization processes. Three coastal systems of Cadiz Bay (SW Spain) (Guadalete River, Rio San Pedro Creek and Sancti Petri Channel) were chosen to determine the seasonal variation of organic matter mineralization. Two sampling stations were selected in each system; one in the outer part, close to the bay, and another more inland, close to a discharge point of effluent related to anthropogenic activities. Seasonal variation revealed that metabolic reactions were driven by the annual change of temperature in the outer station of the systems. In contrast, these reactions depended on the amount of organic matter reaching the sediments in the outermost part of the systems, which was higher during winter. Oxygen is consumed in the first 0.5 cm indicating that suboxic and anoxic processes, such as denitrification, sulfate reduction and methanogenesis are important in these sediments. Sulfate reduction seems to account for most of the mineralization of organic matter at the marine stations, while methanogenesis is the main pathway at the sole freshwater station of this study, located inside the estuary of the Guadalete River, because of the lack of sulfate as electron acceptor. Results point to denitrification being the principal process of N2O formation. Diffusive fluxes varied between 2.6 and 160 mmol m-2 d-1 for dissolved inorganic carbon (DIC); 0.9 and 164.3 mmol m-2 d-1 for TA; 0.8 and 17.4 μmol m-2 d-1 for N2O; and 0.1 μmol and 13.1 mmol m-2 d-1 for CH4, indicating that these sediments act as a source of greenhouse gases to the water column.

  9. Speciation of Metals and Assessment of Contamination in Surface Sediments from Daya Bay, South China Sea

    Directory of Open Access Journals (Sweden)

    Jie Yang

    2014-12-01

    Full Text Available The contents, speciation, source factors and potential ecological risks of the selected metals (Cr, Ni, Cu, Pb, Zn, Cd and As were analyzed in surface sediments from Daya Bay (DYB. The results show that, with the exception of Pb, metal concentrations have decreased at all sites over the past decade. The distribution features of these concentrations represent a ring shape that descends from shore to bay by varying degrees. Speciation analysis showed that Cr, Ni, Cu, Zn and As exist mainly in the residual fraction and, thus, are of low bioavailability, while Cd and Pb were found to be abundant in the non-residual fraction and, thus, have high potential mobility. The ratio of heavy metals in non-residual form in descending order is Pb (78.83%, Cd (78.65%, Cu (48.54%, Zn (48.10%, Ni (38.31%, Cr (28.43% and As (27.76%. The ratio of Pb content is the highest, meaning the highest mobility of Pb. The metals’ potential ecological risks to the environment were also assessed using the methods of the mean effect range-median quotient and the criteria of risk assessment code. The results showed that Cd presents the highest risk, and Pb and Cu are generally considered to be medium risks in the sub-basins of Daya Bay. The principal component analysis (PCA revealed that natural coastal weathering and erosion of rock caused the highest input, followed by mariculture and industrial wastewater and, finally, domestic sewage discharge.

  10. Relationship between chemical composition and magnetic susceptibility in sediment cores from Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Parthiban, G.; Banakar, V.K.; Tomer, A.; Kulkarni, M.

    Three sediment cores in a north–south transect (3 degrees N to 13 degrees S) from different sediment types of the Central Indian Ocean Basin (CIOB) are studied to understand the possible relationship between magnetic susceptibility (Chi) and Al, Fe...

  11. Sediment grab data from October 1999 in Apalachicola Bay, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Apalachicola Bay National Estuarine Research Reserve and the NOAA Office for Coastal Management worked together to map benthic habitats within Apalachicola Bay,...

  12. Oil spill aftermath : temporal evaluation of hydrocarbon sources in Guanabara Bay, Brazil

    International Nuclear Information System (INIS)

    Meniconi, M.F.G.; Massone, C.G.; Scofield, A.L.; Junior, V.J.F.

    2005-01-01

    The sources of polycyclic aromatic hydrocarbons (PAH) in environmental ecosystems are both natural and anthropogenic. PAHs interact with different types of environmental compartments and are subject to processes that lead to geochemical fates such as physical-chemical transformation, biodegradation and photo-oxidation. This study examined the sources of PAHs in the estuarine sediment of Guanabara Bay, Brazil following an accidental oil spill from an oil refinery in January 2000. The main portion of the oil was carried by tidal currents and wind. It spread over the water and reached islands and shorelines at the north part of the bay. The objective of this study was to determine the likely sources of hydrocarbons in the bay where untreated municipal sewage and industrial wastes are also dumped. Sediment samples were collected using cores and dredges from the intertidal and subtidal regions of the bay, reflecting both affected and unaffected areas. This paper summarized the results of 16 EPA priority PAH and their alkylated homologues from 21 sediment samples collected in the bay 10 days after the oil spill, immediately after the clean up effort, and then 3 years later. The hydrocarbon source was determined using PAH ratios for the samples studied. The highest PAH concentration was observed in 2000 as a result of the petrogenic and pyrolytic contribution to the sediments. 38 refs., 3 tabs., 9 figs

  13. Sedimentation, sediment quality, and upstream channel stability, John Redmond Reservoir, east-central Kansas, 1964-2009

    Science.gov (United States)

    Juracek, Kyle E.

    2010-01-01

    A combination of available bathymetric-survey information, bottom-sediment coring, and historical streamgage information was used to investigate sedimentation, sediment quality, and upstream channel stability for John Redmond Reservoir, east-central Kansas. Ongoing sedimentation is reducing the ability of the reservoir to serve several purposes including flood control, water supply, and recreation. The total estimated volume and mass of bottom sediment deposited between 1964 and 2009 in the conservation pool of the reservoir was 1.46 billion cubic feet and 55.8 billion pounds, respectively. The estimated sediment volume occupied about 41 percent of the conservation-pool, water-storage capacity of the reservoir. Water-storage capacity in the conservation pool has been lost to sedimentation at a rate of about 1 percent annually. Mean annual net sediment deposition since 1964 in the conservation pool of the reservoir was estimated to be 1.24 billion pounds per year. Mean annual net sediment yield from the reservoir basin was estimated to be 411,000 pounds per square mile per year Information from sediment cores shows that throughout the history of John Redmond Reservoir, total nitrogen concentrations in the deposited sediment generally were uniform indicating consistent nitrogen inputs to the reservoir. Total phosphorus concentrations in the deposited sediment were more variable than total nitrogen indicating the possibility of changing phosphorus inputs to the reservoir. As the principal limiting factor for primary production in most freshwater environments, phosphorus is of particular importance because increased inputs can contribute to accelerated reservoir eutrophication and the production of algal toxins and taste-and-odor compounds. The mean annual net loads of total nitrogen and total phosphorus deposited in the bottom sediment of the reservoir were estimated to be 2,350,000 pounds per year and 1,030,000 pounds per year, respectively. The estimated mean annual

  14. Removal efficiency of 75Se, 51Cr and 60Co from tidal water by mangrove sediments from Sepetiba Bay (SE Brazil)

    International Nuclear Information System (INIS)

    Suzuki, K.N.; Lopes, R.T.; Machado, E.C.; Machado, W.; Osso, J.A.Jr.

    2014-01-01

    Mangrove sediment cores sampled from Sepetiba Bay (SE Brazil) were covered with tidal water spiked with 75 Se, 51 Cr and 60 Co to evaluate the removal efficiency of these radiotracers by underlying sediments. Variable time-evolution trends were observed along 115 h experiments, with significant differences between removal efficiencies of all radiotracers observed only after 70 h ( 51 Cr > 60 Co > 75 Se). After an event of 60 Co release back to overlying water, there was a general trend of lower 60 Co removal than observed for other radiotracers during the period from 20 to 54 h. After this event, alternated periods of higher 60 Co and higher 75 Se removal trends were observed, attributed to behavioural differences expected for such anionic and cationic radiotracers. While 75 Se and 51 Cr showed uniform time-evolution curves, as typically found in the literature for most radiotracers, 60 Co removal rates presented oscillations, probably due to sensitivity to changes in redox conditions within underlying sediments. Results evidenced the role of mangrove sediments as trace element sinks, which have implications for coastal water quality and for possible uses of such sediments in wastewater treatment systems. (author)

  15. Fatty acids and Pb-210 geochronology of a sediment core from Buzzards Bay, Massachusetts

    International Nuclear Information System (INIS)

    Farrington, J.W.; Henrichs, S.M.; Anderson, R.

    1977-01-01

    Four sections of a Pb-210 dated core of 62 cm length from Buzzards Bay, Massachusetts, were analyzed for fatty acids. A comparison of fatty acids extracted by Soxhlet extraction (unbound fatty acids) with fatty acids extracted by subsequent saponification extraction of the same sample (bound fatty acids) showed that the former did not undergo diagenetic loss any faster than the latter. However, compositional differences between bound and unbound fatty acids were apparent in the top section of 1 to 2 cm and were less apparent in the 54 to 58 cm section. At least 14% of the bound fatty acids are esterified to non-solvent extractable material. The net conversion of fatty acids to other compounds is 32 μg/g dry weight sediment over the first 30 yr after deposition. (author)

  16. Water Quality and Sedimentation Data of the Coastal Intensive Site Network (CISNet) Long Term Monitoring Sites in Kaneohe Bay, Oahu, Hawaii from 1998 to 2001 (NODC Accession 0001473)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A long term project to monitor water quality and sediment processes in Kaneohe Bay was initiated in November 1998 and continued through July 2001. Four primary sites...

  17. Water quality in South San Francisco Bay, California: current condition and potential issues for the South Bay Salt Pond Restoration Project.

    Science.gov (United States)

    Grenier, J Letitia; Davis, Jay A

    2010-01-01

    The SBSPRP is an extensive tidal wetland restoration project that is underway at the margin of South San Francisco Bay, California. The Project, which aims to restore former salt ponds to tidal marsh and manage other ponds for water bird support, is taking place in the context of a highly urbanized watershed and an Estuary already impacted by chemical contaminants. There is an intimate relationship between water quality in the watershed, the Bay, and the transitional wetland areas where the Project is located. The Project seeks to restore habitat for endangered and endemic species and to provide recreational opportunities for people. Therefore, water quality and bioaccumulation of contaminants in fish and wildlife is an important concern for the success of the Project. Mercury, PCBs, and PBDEs are the persistent contaminants of greatest concern in the region. All of these contaminants are present at elevated concentrations both in the abiotic environment and in wildlife. Dioxins, pyrethroids, PAHs, and selenium are also problematic. Organochlorine insecticides have historically impacted the Bay, and they remain above thresholds for concern in a small proportion of samples. Emerging contaminants, such as PFCs and non-PBDE flame retardants, are also an important water quality issue. Beyond chemical pollutants, other concerns for water quality in South San Francisco Bay exist, and include biological constituents, especially invasive species, and chemical attributes, such as dissolved oxygen and salinity. Future changes, both from within the Project and from the Bay and watershed, are likely to influence water quality in the region. Project actions to restore wetlands could worsen, improve, or not affect the already impaired water quality in South Bay. Accelerated erosion of buried sediment as a consequence of Project restoration actions is a potentially serious regional threat to South Bay water and sediment quality. Furthermore, the planned restoration of salt ponds

  18. Distribution and possible sources of some heavy metals in the sediment cores at the front bay (Carter) and Labor Island (Khor Maksar), Aden (Yemen)

    International Nuclear Information System (INIS)

    Ali, Anis Ahmed

    2004-01-01

    Metal contents (Cd, Co,Cu,Fe,Mn,Pb an Zn) in the sediments are measured in the same cores that collected and determined by using atomic absorption spectrometric (AAS) method. two areas were chosen in Aden, Labor Island, and front Bay. The vertical sequence of sedimentary structures reflected variations in processes and rates of sedimentation with ti,e. The difference in metal concentration between the recent (upper) and the historical (lower) sediments is defined as the anthropogenic metal concentration. the series of studied cores, gave a regional picture of the sediments, metal fluxes, the calculated budgets for sediments, and metal deposition. Statistically, significant correlations (p<0.01) between concentrations of selected metals were observed, fractions < 100μm and < 250μm are the best to accumulate the heavy metals. Improvement of the situation in the two studied areas during the last decades is reflected by the decrease in anthropogenic fluxes into these areas. (author)

  19. Comparing sediment quality in Spanish littoral areas affected by acute (Prestige, 2002) and chronic (Bay of Algeciras) oil spills

    International Nuclear Information System (INIS)

    Morales-Caselles, C.; Kalman, J.; Riba, I.; DelValls, T.A.

    2007-01-01

    The quality of sediments collected from two areas of the Spanish coast affected by different sources of contaminants has been compared in this study. The areas studied are the coast of Galicia affected by the oil spill from the tanker Prestige (November 2002) and the Gulf of Cadiz which suffers continuous inputs of contaminants from industries located in the area and from oil spills. Contamination by several chemicals (metals, PCBs and PAHs) that bind to sediments was analyzed, and two toxicity tests (Microtox[reg]) and amphipod 10-day bioassay) were conducted. PAHs were identified as the compounds responsible for the toxic effects. Results show differences between an acute impact related to the sinking of the tanker Prestige and the chronic impact associated with continuous oil spills associated with the maritime and industrial activities in the Bay of Algeciras, this being the most polluted part of the two coastal areas studied in this work. - Littoral sediments affected by low or moderated but continuous oil spills are more polluted than those affected by accidental oil spills such as the Prestige

  20. Incorporating Contaminant Bioavailability into Sediment Quality Assessment Frameworks

    Science.gov (United States)

    The recently adopted sediment quality assessment framework for evaluating bay and estuarine sediments in the State of California incorporates bulk sediment chemistry as a key line of evidence(LOE) but does not address the bioavailability of measured contaminants. Thus, the chemis...

  1. Morphology and sediment dynamics of the Capbreton canyon (Bay of Biscay, SW France)

    Science.gov (United States)

    Gaudin, M.; Umr 5805; Ifremer Team

    2003-04-01

    The Canyon of Capbreton extending in the Bay of Biscay (SW France) is the deepest canyon in the world. Its structure and morphology was studied using new multibeam bathymetry, acoustic imagery and high-resolution seismic data. The canyon head appears only 250 m away from the coast line and runs westward parallel to the north coast of Spain for 160 km due to structural control, then turns northward, widens and abruptly disappears in the continental rise by 3500 m water depth. Its northern margin is flat and progrades clearly westward. Conversely the southern margin is steep and progrades towards the north (i.e. towards the canyon). Down to 800 m water depth, the canyon deeply incises the continental shelf and the axial channel is meandering (sinuosity of 1.9). The canyon shows both major and minor stream beds, perched tributary valleys, nested terraces and abandoned meanders. The terraces have three morphologies: (1) flat, (2) with a raised side or (3) with a horseshoe structure. These morphologies have been interpreted as overbank deposits or nested levees (1 and 2) or as the result of meander abandon (3). Terraces of types (1) and (2) contain mainly fine deposits resulting from decantation of the top of turbulent surges that flow in the canyon. Westward (800 to 2000 m water depth) the main talweg remains sinuous (1.7). On the southern margin, several straight or slightly sinuous S-N tributary valleys are followed by alignments of pockmarks that also indicate a structural control. On the northern margin, a single large tributary valley with a sinuous central talweg, flowing from the upper Aquitaine continental slope, is interpreted as a giant slump scar due to sediment instability. This valley is bordered to the west by a topographic high with sediment waves on the external flank that might be interpreted as a sedimentary levee. The canyon recorded a recent turbidite activity. An 18 cm-thick turbidite was deposited at 650 m water depth by a turbidity current

  2. The filling of the Ria de Gernika (Bay of Biscay) since the late Holocene

    International Nuclear Information System (INIS)

    Pascual, A.; Rodriguez-Lazaro, J.; Weber, O.; Jouanneau, J.M.; Pujos, M.

    1998-01-01

    A study of the recent sedimentation of the ria de Gernika (Bay of Biscay) is undertaken to characterise different steps of its Holocene filling. Sedimentological and micropalaeontological analysis of six cores sampled in the ria, completed with absolute dating ( 14 C, and based upon 210 Pb exc.), allow us to identify three phases in the filling of the ria that are limited by two transgressive shifts (3500 and 2500 yr. B.P.) already described in other areas of the Bay of Biscay. In the first phase, lithologies as well as benthic foraminifera and ostracode assemblages are typical of coastal marine palaeo-environment. During the second phase the euryhaline waters progressively occupy the central area of the estuary. Here the presence of allochthonous micro-fauna, particularly of planktonic foraminifera, indicates an increase of exchanges with marine waters that can reach the inner areas of the estuarine system. The last phase (2500 yr. B.P. to the present), which corresponds to the recent and active sedimentation, is marked by an impoverishment of the micro-faunas, the filling of some channels and the increase of salt marshes. The estimated sedimentation rate for the upper decimeters of the cores (0.73-1.29 cm.yr -1 ) shows faster sedimentary filling of the ria with anthropic action evidenced by the presence of metallic contaminants and hypohaline micro-fauna. (authors)

  3. Caesium and Plutonium Isotopes as Tracers of Various Events in Sediment Records in the Bay of Toulon (Northwestern Mediterranean Sea)

    Energy Technology Data Exchange (ETDEWEB)

    Duffa, C.; Arnaud, M.; Charmasson, S.; Thebault, H. [Institut de Radioprotection et de Surete Nucleaire, DEI/SESURE/LERCM, La Seyne sur Mer (France)

    2013-07-15

    Located along the French Mediterranean coast, the Toulon bay has a specific configuration with two basins. The shallow one is a semi-enclosed basin (Petite Rade) with complex hydrodynamic conditions that contribute to fine sedimentation. The open sea basin, separated from the first one by a long sea wall, receives different anthropogenic inputs. Surface and core sediment sampling cruises took place in 2001 and 2008, in order to study radionuclide spatial dispersion and sediment accumulation. {sup 137}Cs values are statistically higher in the 'Petite Rade' than in the open basin. {sup 239+240}Pu levels range from 0.7 to 2.6 Bq/kg dry weight in surface sediments, up to 6 times higher than elsewhere in Mediterranean coastal areas not influenced by riverine inputs. Plutonium activity ratios ({sup 238}Pu/{sup 239+240}Pu and {sup 239}Pu/{sup 240}Pu) labelled atmospheric nuclear weapon testing. Regarding the long cores, the highest plutonium activities, measured by alpha counting and ICP-MS, concern the first ten centimetres with a maximum value of 3.5 Bq/kg dry weight in {sup 239+240}Pu. (author)

  4. Virgin Islands: Coral Bay Watershed Management (A Former EPA CARE Project)

    Science.gov (United States)

    The Coral Bay Watershed Management is a recipient of the Level II CARE cooperative agreement to continue and expand its collective efforts to stop erosion, sediment, and storm-water pollution of Coral Bay, improve solid waste management,

  5. Hydrographical features of the southern and central Bay of Bengal during the transition period between winter and summer

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, L.V.G.; Jayaraman, R.

    During Feb.-Mar. 1963, INS KISTNA has carried out its 6th and 7th oceanographic cruises in the southern and central parts of Bay of Bengal under the Indian Programme of IIOE. With the physical oceanographic data collected in these cruises...

  6. Dispersal of thermophilic Desulfotomaculum endospores into Baltic Sea sediments over thousands of years

    DEFF Research Database (Denmark)

    Rezende, Julia Rosa de; Kjeldsen, Kasper Urup; Hubert, Casey RJ

    2013-01-01

    S rRNA and of the dissimilatory (bi)sulfite reductase (dsrAB) genes within the endospore-forming SRB genus Desulfotomaculum. The thermophilic Desulfotomaculum community in Aarhus Bay sediments consisted of at least 23 species-level 16S rRNA sequence phylotypes. In two cases, pairs of identical 16S r......RNA and dsrAB sequences in Arctic surface sediment 3000km away showed that the same phylotypes are present in both locations. Radiotracer-enhanced most probable number analysis revealed that the abundance of endospores of thermophilic SRB in Aarhus Bay sediment was ca. 104 per cm3 at the surface and decreased...... in water masses preceding sedimentation. The sources of these thermophiles remain enigmatic, but at least one source may be common to both Aarhus Bay and Arctic sediments....

  7. Dispersal of thermophilic Desulfotomaculum endospores into Baltic Sea sediments over thousands of years.

    Science.gov (United States)

    de Rezende, Júlia Rosa; Kjeldsen, Kasper Urup; Hubert, Casey R J; Finster, Kai; Loy, Alexander; Jørgensen, Bo Barker

    2013-01-01

    Patterns of microbial biogeography result from a combination of dispersal, speciation and extinction, yet individual contributions exerted by each of these mechanisms are difficult to isolate and distinguish. The influx of endospores of thermophilic microorganisms to cold marine sediments offers a natural model for investigating passive dispersal in the ocean. We investigated the activity, diversity and abundance of thermophilic endospore-forming sulfate-reducing bacteria (SRB) in Aarhus Bay by incubating pasteurized sediment between 28 and 85 °C, and by subsequent molecular diversity analyses of 16S rRNA and of the dissimilatory (bi)sulfite reductase (dsrAB) genes within the endospore-forming SRB genus Desulfotomaculum. The thermophilic Desulfotomaculum community in Aarhus Bay sediments consisted of at least 23 species-level 16S rRNA sequence phylotypes. In two cases, pairs of identical 16S rRNA and dsrAB sequences in Arctic surface sediment 3000 km away showed that the same phylotypes are present in both locations. Radiotracer-enhanced most probable number analysis revealed that the abundance of endospores of thermophilic SRB in Aarhus Bay sediment was ca. 10(4) per cm(3) at the surface and decreased exponentially to 10(0) per cm(3) at 6.5 m depth, corresponding to 4500 years of sediment age. Thus, a half-life of ca. 300 years was estimated for the thermophilic SRB endospores deposited in Aarhus Bay sediments. These endospores were similarly detected in the overlying water column, indicative of passive dispersal in water masses preceding sedimentation. The sources of these thermophiles remain enigmatic, but at least one source may be common to both Aarhus Bay and Arctic sediments.

  8. Ecological evaluation of proposed dredged material from St. Andrew Bay, Florida

    International Nuclear Information System (INIS)

    Mayhew, H.L.; Word, J.Q.; Kohn, N.P.; Pinza, M.R.; Karle, L.M.; Ward, J.A.

    1993-10-01

    The US Army Corps of Engineers (USACE), Mobile District, requested that the Battelle/Marine Sciences Laboratory (MSL) conduct field sampling and chemical and biological testing to determine the suitability of potential dredged material for open ocean disposal. Sediment from St. Andrew Bay was chemically characterized and evaluated for biological toxicity and bioaccumulation of contaminants. The Tier III guidance for ocean disposal testing requires tests of water column effects (following dredged material disposal), deposited sediment toxicity, and bioaccumulation of contaminants from deposited sediment (dredged material). To meet these requirements, the MSL conducted suspended-particulate-phase (SPP) toxicity tests, solid-phase toxicity tests, and bioaccumulation testing on sediment representing potential dredged material from Panama City Harbor. Physical and chemical characterization of sediment to support toxicity and bioaccumulation results was also conducted on both the test and reference sediments. The MSL collected sediment samples from five sites in St. Andrew Bay and one reference site near Lands End Peninsula. The five test sediments and the reference sediment were analyzed for physical and chemical sediment characteristics, SPP chemical contaminants, solid-phase toxicity, SPP toxicity, and bioaccumulation of contaminants

  9. Intertidal sediments and benthic animals of Roebuck Bay, Western Australia

    NARCIS (Netherlands)

    Pepping, M.; Piersma, T.; Pearson, G.; Lavaleye, M.

    1999-01-01

    Roebuck Bay near Broome (NW Australia) is with itsextensive tidal flats one of the foremost internationallyimportant sites for shorebirds in the Asia-Pacificflyway system. It is home to 150,000 shorebirds (or‘waders’) in the nonbreeding season, which suggeststhat the intertidal flats of the bay have

  10. Use of Geographic Information Systems to examine cumulative impacts of development on Mobile Bay, AL and Galveston Bay, TX

    International Nuclear Information System (INIS)

    Rosigno, P.F.; McNiff, M.E.; Watzin, M.C.; Ji, W.

    1993-01-01

    Databases from Mobile Bay, Alabama and Galveston Bay, Texas were compiled using ARC/INFO Geographic Information Systems (GIS) to examine the cumulative impacts from urbanization and industrialization on these two Gulf of Mexico estuaries. The databases included information on wetland habitats, pollution sources, metal contamination, bird-nesting sites, and oyster reefs, among others. A series of maps were used to represent the impacts within and between each ecosystem. These two estuaries share many similarities in the types of developmental pressures that each experience. However, difference in the magnitude of industrial activity, pollution loading, and urban growth coupled with distinct hydrodynamic and geochemical differences in sediment mineralogy, freshwater inflows and salinity regimens results in differing responses. With growing human population and extensive oil and gas development, the demands on Galveston Bay are quite different than those placed on Mobile Bay which has lower growth and less extensive oil and gas infrastructure. Mobile Bay tends to retain whatever contamination enters into the system because of the high levels of clay and organic carbon found in its sediment. Some of these chemicals bioaccumulate, posing an extra risk to natural resources. Geographic Information Systems provide natural resource managers with the technology to manage complex databases. The analytical and mapping capabilities of GIS can be used to consider cumulative effects in a regional context and to develop plans to protect ecologically sensitive areas

  11. Sup(10)Be variation in surficial sediments of the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Aldahan, A.; Possnert, G.; Selvaraj, K.; Mascarenhas-Pereira, M.B.L.; Chen, C.T.A.

    Distribution of 10Be in systematically collected (degree + degree interval at 10 to 16 degrees S; 73.5 to 76.5 degrees E) surficial siliceous ooze, siliceous clay and pelagic clay sediments (top 2 cm) from the abyssal Central Indian Basin...

  12. Local controls on sediment accumulation and distribution in a fjord in the West Antarctic Peninsula: implications for palaeoenvironmental interpretations

    Directory of Open Access Journals (Sweden)

    Yuribia P. Munoz

    2016-08-01

    Full Text Available We analyse surface sediment and its distribution in Flandres Bay, West Antarctic Peninsula, in order to understand modern day sediment dispersal patterns in a fjord with retreating, tidewater glaciers. The surface sediment descriptions of 41 cores are included in this study. The sediment facies described include muddy diatomaceous ooze, diatomaceous mud, pebbly mud, sandy mud and mud, with scattered pebbles present in most samples. In contrast to a traditional conceptual model of glacial sediment distribution in fjords, grain size in Flandres Bay generally coarsens from the inner to outer bay. The smallest grain size sediments were found in the bay head and are interpreted as fine-grained deposits resulting from meltwater plumes and sediment gravity flows occurring close to the glacier front. The middle of the bay is characterized by a high silt percentage, which correlates to diatom-rich sediments. Sediments in the outer bay have a high component of coarse material, which is interpreted as being the result of winnowing from currents moving from the Bellingshausen Sea into the Gerlache Strait. Palaeoenvironmental reconstructions of glacial environments often use grain size as an indicator of proximity to the ice margin. After a detailed analysis of a large number of cores collected in the study area, our findings highlight the variability in sedimentation patterns within a fjord and provide a valuable evidence of the complexity that may occur in the sedimentary record.

  13. Radioactivity of some alpha, beta and gamma emitting radionuclides in surface marine sediments of different bays in Algeria

    International Nuclear Information System (INIS)

    Noureddine, A.; Baggoura, B.

    1999-01-01

    Samples of surface (0-15) cm marine sediments of different grain sizes, namely sand, muddy and fine sand, were collected in the western, central and east coast of Algeria, to measure concentrations of natural and artificial radioactivity. The aim of this study is to detect any radioactive contamination, its origin and also to determine the uptake of radioactivity by marine surface sediments

  14. Wind-enhanced resuspension in the shallow waters of South San Francisco Bay: Mechanisms and potential implications for cohesive sediment transport

    Science.gov (United States)

    Brand, Andreas; Lacy, Jessica R.; Hsu, Kevin; Hoover, Daniel; Gladding, Steve; Stacey, Mark T.

    2010-01-01

    We investigated the driving forces of sediment dynamics at the shoals in South San Francisco Bay. Two stations were deployed along a line perpendicular to a 14 m deep channel, 1000 and 2000 m from the middle of the channel. Station depths were 2.59 and 2.19 m below mean lower low water, respectively. We used acoustic Doppler velocimeters for the simultaneous determination of current velocities, turbulence, sediment concentration and fluxes. Maximum current shear velocities were 0.015 m s−1 at the station further from the channel (closer to the shore) and 0.02 m s−1 at the station closer to the channel. Peak wave-induced shear velocities exceeded 0.015 m s−1 at both stations. Maximum sediment concentrations were around 30 g m−3 during calm periods (root mean square wave height −3 and sediment fluxes were 5 times higher than in calm conditions (0.02 g m−2 s−1 versus >0.10 g m−2 s−1) at the station further from the channel 0.36 m above the bed. Closer to the channel, sediment concentrations and vertical fluxes due to wind wave resuspension were persistently lower (maximum concentrations around 50 g m−3 and maximum fluxes around 0.04 g m−2 s−1). Most resuspension events occurred during flood tides that followed wave events during low water. Although wave motions are able to resuspend sediment into the wave boundary layer at low tide, the observed large increases in sediment fluxes are due to the nonlinear interaction of wind waves and the tidal currents.

  15. Americium and plutonium in water, biota, and sediment from the central Oregon coast

    International Nuclear Information System (INIS)

    Nielsen, R.D.

    1982-06-01

    Plutonium-239, 240 and americium-241 were measured in the mussel Mytilus californianus from the region of Coos Bay, OR. The flesh of this species has a plutonium concentration of about 90 fCi/kg, and an Am-241/Pu-239, 240 ratio that is high relative to mixed fallout, ranging between two and three. Transuranic concentrations in sediment, unfiltered water, and filterable particulates were also measured; none of these materials has an Am/Pu ratio as greatly elevated as the mussels, and there is no apparent difference in the Am/Pu ratio of terrestrial runoff and coastal water. Sediment core profiles do not allow accumulation rates or depositional histories to be identified, but it does not appear that material characterized by a high Am/Pu ratio has ever been introduced to this estuary. Other bivalves (Tresus capax and Macoma nasuta) and a polychaete (Abarenicola sp.) do not have an elevated Am/Pu ratio, although the absolute activity of plutonium in the infaunal bivalves is roughly four times that in the mussels

  16. Fluvial fluxes from the Magdalena River into Cartagena Bay, Caribbean Colombia: Trends, future scenarios, and connections with upstream human impacts

    Science.gov (United States)

    Restrepo, Juan D.; Escobar, Rogger; Tosic, Marko

    2018-02-01

    Fluxes of continental runoff and sediments as well as downstream deposition of eroded soils have severely altered the structure and function of fluvial and deltaic-estuarine ecosystems. The Magdalena River, the main contributor of continental fluxes into the Caribbean Sea, delivers important amounts of water and sediments into Cartagena Bay, a major estuarine system in northern Colombia. Until now, trends in fluvial fluxes into the bay, as well as the relationship between these tendencies in fluvial inputs and associated upstream changes in the Magdalena catchment, have not been studied. Here we explore the interannual trends of water discharge and sediment load flowing from the Magdalena River-Canal del Dique system into Cartagena Bay during the last three decades, forecast future scenarios of fluxes into the bay, and discuss possible connections between observed trends in fluvial inputs and trends in human intervention in the Magdalena River basin. Significant upward trends in annual runoff and sediment load during the mid-1980s, 1990s, and post-2000 are observed in the Magdalena and in the Canal del Dique flowing into Cartagena Bay. During the last decade, Magdalena streamflow and sediment load experienced increases of 24% and 33%, respectively, compared to the pre-2000 year period. Meanwhile, the Canal del Dique witnessed increases in water discharge and sediment load of 28% and 48%, respectively. During 26 y of monitoring, the Canal del Dique has discharged 177 Mt of sediment to the coastal zone, of which 52 Mt was discharged into Cartagena Bay. Currently, the Canal drains 6.5% and transports 5.1% of the Magdalena water discharge and sediment load. By 2020, water discharge and sediment flux from the Canal del Dique flowing to the coastal zone will witness increments of 164% and 260%, respectively. Consequently, sediment fluxes into Cartagena Bay will witness increments as high as 8.2 Mt y- 1 or 317%. Further analyses of upstream sediment load series for 21

  17. Mesozooplankton production, grazing and respiration in the Bay of Bengal: Implications for net heterotrophy

    Science.gov (United States)

    Fernandes, Veronica; Ramaiah, N.

    2016-03-01

    Mesozooplankton samples were collected from the mixed layer along a central (along 88°E) and a western transect in the Bay of Bengal during four seasons covered between 2001 and 2006 in order to investigate spatio-temporal variability in their biomass. At these stations, grazing and respiration rates were measured from live zooplankton hauled in from the surface during December 2005. Akin to the mesozooplankton "paradox" in the central and eastern Arabian Sea, biomass in the mixed layer was more or less invariant in the central and western Bay of Bengal, even as the chl a showed marginal temporal variation. By empirical equation, the mesozooplankton production rate calculated to be 70-246 mg C m- 2 d- 1 is on par with the Arabian Sea. Contrary to the conventional belief, mesozooplankton grazing impact was up to 83% on primary production (PP). Low PP coupled with very high zooplankton production (70% of PP) along with abundant bacterial production (50% of the PP; Ramaiah et al., 2009) is likely to render the Bay of Bengal net heterotrophic, especially during the spring intermonsoon. Greater estimates of fecal pellet-carbon egestion by mesozooplankton compared to the average particulate organic carbon flux in sediment traps, implies that much of the matter is recycled by heterotrophic communities in the mixed layer facilitating nutrient regeneration for phytoplankton growth. We also calculated that over a third of the primary production is channelized for basin-wide zooplankton respiration that accounts for 52 Mt C annually. In the current scenario of global warming, if low (primary) productive warm pools like the Bay of Bengal continue to be net heterotrophic, negative implications like enhanced emission of CO2 to the atmosphere, increased particulate flux to the deeper waters and greater utilization of dissolved oxygen resulting in expansion of the existing oxygen minimum zone are imminent.

  18. Nature and distribution of manganese nodules from three sediment domains of the Central Indian Basin, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Mukhopadhyay, R.

    from northern and central region, dominatEd. by terrigenous and terrigenous-siliceous mixed sediments, respectively. Effects of lysocline and sediment diagenesis are envisaged for trace metal enrichment in rough nodules of the southern region. Influence...

  19. Superficial distribution of aromatic compounds and geomicrobiology of sediments from Suruí Mangrove, Guanabara Bay, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz F. Fontana

    2010-12-01

    Full Text Available The distribution of selected aromatic compounds and microbiology were assessed in superficial sediments from Suruí Mangrove, Guanabara Bay. Samples were collected at 23 stations, and particle size, organic matter, aromatic compounds, microbiology activity, biopolymers, and topography were determined. The concentration of aromatic compounds was distributed in patches over the entire mangrove, and their highest total concentration was determinated in the mangrove's central area. Particle size differed from most mangroves in that Suruí Mangrove has chernies on the edges and in front of the mangrove, and sand across the whole surface, which hampers the relationship between particle size and hydrocarbons. An average @ 10% p/p of organic matter was obtained, and biopolymers presented high concentrations, especially in the central and back areas of the mangrove. The biopolymers were distributed in high concentrations. The presence of fine sediments is an important factor in hydrocarbon accumulation. With high concentration of organic matter and biopolymers, and the topography with chernies and roots protecting the mangrove, calmer areas are created with the deposition of material transported by wave action. Compared to global distributions, concentrations of aromatic compounds in Suruí Mangrove may be classified from moderate to high, showing that the studied area is highly impacted.A distribuição de compostos aromáticos selecionados e a microbiologia foram avaliados em sedimentos superficiais do Manguezal de Suruí, Baía de Guanabara. Amostras foram coletadas em 23 pontos e determinados a granulometria, matéria orgânica, compostos aromáticos, atividade microbiológica, biopolímeros e a topografia. A concentração dos compostos aromáticos foi distribuída em manchas por todo o manguezal e sua concentração total mais elevada foi encontrada na área central do manguezal. A granulometria diferiu da maioria dos manguezais, uma vez que no

  20. Single-beam bathymetry data collected in 2015 from Grand Bay, Alabama-Mississippi

    Science.gov (United States)

    DeWitt, Nancy T.; Stalk, Chelsea A.; Smith, Christopher G.; Locker, Stanley D.; Fredericks, Jake J.; McCloskey, Terrence A.; Wheaton, Cathryn J.

    2017-12-01

    As part of the Sea-level and Storm Impacts on Estuarine Environments and Shorelines (SSIEES) project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted a single-beam bathymetry survey within the estuarine, open-bay, and tidal creek environments of Grand Bay, Alabama-Mississippi, from May to June 2015. The goal of the SSIEES project is to assess the physical controls of sediment and material exchange between wetlands and estuarine environments along the northern Gulf of Mexico, specifically Grand Bay, Alabama-Mississippi; Vermilion Bay, Louisiana; and, along the east coast, within Chincoteague Bay, Virginia-Maryland. The data described in this report provide baseline bathymetric information for future research investigating wetland-marsh evolution, sediment transport, erosion, recent and long-term geomorphic change, and can also support the modeling of changes in response to restoration and storm impacts. The survey area encompasses more than 40 square kilometers of Grand Bay’s waters.

  1. Spatial distribution of iron, copper and lead in mangrove sediments in a degradation gradient in Guanabara Bay (Rio de Janeiro State)

    OpenAIRE

    Borges, Anderson C.; Dias, Jailson C.; Machado, Wilson; Patchineelam, Sambasiva R.; Sella, Silvia M.

    2007-01-01

    Iron, copper and lead distribution was evaluated in sediment cores from a disturbed mangrove area in Guanabara Bay: a core from a seaward site where mangrove vegetation was removed ~20 yr before sampling (MD); a core from an intermediate site with dead vegetation, apparently due to insect attack (MP), and a core from a landward site with living vegetation (MV). Metal concentrations showed increasing values seaward while organic matter content showed an inverse trend, displaying a negative cor...

  2. Speciation of heavy metals Cu, Ni and Zn by modified BCR sequential extraction procedure in sediments from Banten Bay, Banten Province, Indonesia

    Science.gov (United States)

    Lestari; Budiyanto, F.; Hindarti, D.

    2018-02-01

    Banten Bay is categorized as a marine area that is busy with marine tourism activities, settlements and also industries. One potential impact of the condition is the occurrence of pollution from both industrial and domestic sources, erosion and sedimentation in the coastal environment. Samples were collected from 25 representative stations in April 2016. Chemical speciation of three heavy metals (Cu, Ni, and Zn) was studied using a modified sequential extraction procedure proposed by the European Standard, Measurements and Testing (SM&T) program, formerly the Community Bureau of Reference (BCR). The aims of this study are to determine geochemical speciation of 4 bounds of metal: acid-soluble, reducible, oxidizable and residual, and to assess their impacts in the sediments of Banten Bay, Indonesia. The result shows that the percentage of Copper (45.90-83.75%), Nickel (18.28-65.66%), and Zinc (30.45-79.51%) were mostly accumulated in residual fraction of the total concentrations. The Risk Assessment Code (RAC) reveals that about 0-7.07% of Copper and 1.11-24.35 % of Zinc at sites exist in exchangeable fraction and therefore, they are in low risk category. While 7.34-34.90 of Ni at sites exists in exchangeable fraction and therefore, it is in medium risk category to aquatic environment.

  3. Sources and historical record of tin and butyl-tin species in a Mediterranean bay (Toulon Bay, France).

    Science.gov (United States)

    Pougnet, Frédérique; Schäfer, Jörg; Dutruch, Lionel; Garnier, Cédric; Tessier, Erwan; Dang, Duc Huy; Lanceleur, Laurent; Mullot, Jean-Ulrich; Lenoble, Véronique; Blanc, Gérard

    2014-05-01

    Concentrations of inorganic tin (Sn(inorg)), tributyltin (TBT) and its degradation products dibutyltin (DBT) and monobutyltin (MBT) were measured in surface sediments and in two cores from the Toulon Bay, hosting the major French military harbour. Anticipating planned dredging, the aim of the present work is to map and evaluate for the first time the recent and historic contamination of these sediments by inorganic and organic Sn species derived from antifouling paints used for various naval domains including military, trade, tourism and leisure. Tin and butyl-Sn concentrations in the bay varied strongly (4 orders of magnitude), depending on the site, showing maximum values near the shipyards. The concentrations of total Sn (1.3-112 μg g(-1)), TBT (product Sn(inorgBT) is by far the dominant species after 10-12 half-life periods and (c) using recent data to reliably assess former TBT contamination requires the use of a modified butyl-Sn degradation index BDI(mod). Resuspension of extremely contaminated subsurface sediments by the scheduled dredging will probably result in mobilization of important amounts of butyl-Sn species.

  4. Sediment profile image data from October 1999 in Apalachicola Bay, Florida

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Apalachicola Bay National Estuarine Research Reserve and the NOAA Office for Coastal Management worked together to map benthic habitats within Apalachicola Bay,...

  5. Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

    Science.gov (United States)

    Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

    1999-01-01

    Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that

  6. Late Holocene sea-level rise in Tampa Bay: Integrated reconstruction using biomarkers, pollen, organic-walled dinoflagellate cysts, and diatoms

    NARCIS (Netherlands)

    Soelen, E.E. van; Lammertsma, E.I.; Cremer, H.; Donders, T.H.; Sangiorgi, F.; Brooks, G.R.; Larson, R.A.; Sinninghe Damsté, J.S.; Wagner-Cremer, F.; Reichart, G.J.

    2010-01-01

    A suite of organic geochemical, micropaleontological and palynological proxies was applied to sediments from Southwest Florida, to study the Holocene environmental changes associated with sea-level rise. Sediments were recovered from Hillsborough Bay, part of Tampa Bay, and studied using biomarkers,

  7. Volcanic geology and geochemistry of Motuhora (Whale Island), Bay of Plenty, New Zealand

    International Nuclear Information System (INIS)

    Burt, R.M.; Cole, J.W.; Vroon, P.Z.

    1996-01-01

    Motuhora (Whale Island) lies c. 11 km offshore from Whakatane in the Bay of Plenty, New Zealand, and comprises tuffaceous marine sediments of the Camp Bay and Motuhora Formations separated by lavas, volcanic breccias, and slope-wash deposits of the Whale Volcanics. Whale Volcanics can be divided into East Dome, Central Dome Complex, and Pa Hill Dome. East Dome is a flow banded, chaotically jointed dacite that is probably extrusive. Central Dome comprises lava flows, and extensive volcanic breccias and tuffs which thicken into a local depression to the north of the central high, suggesting rapid growth and erosion of the dome. Pa Hill Dome is largely intrusive into Camp Bay Formation, although blocks of Pa Hill dacite in an upper slope-wash cobble bed suggest it was partially extrusive. The lavas are porphyritic with phenocrysts of plagioclase, orthopyroxene, and titanomagnetite with subordinate clinopyroxene and amphibole (particularly in Pa Hill Dome), and rare biotite. Rounded or broken and embayed quartz crystals are found in the Central Dome Complex and Pa Hill domes. Magmatic xenoliths are common in all lavas. Chemically the lavas are medium-K, calc-alkaline andesites and dacites, and show relative LILE enrichment and HFSE depletion typical of arc volcanics. Isotopically, samples tend to have more radiogenic Sr and less radiogenic Nd than volcanics from neighbouring White Island. It is likely that Motuhora lavas were formed by a multi-stage process involving partial melting of N-MORB-type mantle that had been fluxed by fluids rich in incompatible elements derived from the dehydrating downgoing slab and followed by crystal fractionation of the magma. As the magma rose through the lower continental crust it was contaminated, probably by Torlesse metasediment. Petrographic textures and mineral chemistry indicate that magma mixing, while in an upper crustal magma chamber, is the norm for Motuhora lavas. (author). 69 refs., 12 figs., 2 tabs

  8. Combined SEM/AVS and attenuation of concentration models for the assessment of bioavailability and mobility of metals in sediments of Sepetiba Bay (SE Brazil).

    Science.gov (United States)

    Ribeiro, Andreza Portella; Figueiredo, Ana Maria Graciano; dos Santos, José Osman; Dantas, Elizabeth; Cotrim, Marycel Elena Barboza; Figueira, Rubens Cesar Lopes; Silva Filho, Emmanoel V; Wasserman, Julio Cesar

    2013-03-15

    This study proposes a new methodology to study contamination, bioavailability and mobility of metals (Cd, Cu, Ni, Pb, and Zn) using chemical and geostatistics approaches in marine sediments of Sepetiba Bay (SE Brazil). The chemical model of SEM (simultaneously extracted metals)/AVS (acid volatile sulfides) ratio uses a technique of cold acid extraction of metals to evaluate their bioavailability, and the geostatistical model of attenuation of concentrations estimates the mobility of metals. By coupling the two it was observed that Sepetiba Port, the urban area of Sepetiba and the riverine discharges may constitute potential sources of metals to Sepetiba Bay. The metals are concentrated in the NE area of the bay, where they tend to have their lowest mobility, as shown by the attenuation model, and are not bioavailable, as they tend to associate with sulfide and organic matter originated in the mangrove forests of nearby Guaratiba area. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Remotely Sensing Pollution: Detection and Monitoring of PCBs in the San Francisco Bay

    Science.gov (United States)

    Hilton, A.; Kudela, R. M.; Bausell, J.

    2016-12-01

    While the EPA banned polychlorinated biphenyls (PCBs) in 1977, they continue to persist in San Francisco Bay (SF Bay), often at dangerously high concentrations due to their long half-life. However, in spite of their associated health and environmental risks, PCB monitoring within SF Bay is extremely limited, due in large part to the high costs, both in terms of labor and capital that are associated with it. In this study, a cost effective alternative to in-situ PCB sampling is presented by demonstrating the feasibility of PCB detection via remote sensing. This was done by first establishing relationships between in-situ measurements of sum of 40 PCB concentrations and total suspended sediment concentration (SSC) collected from 1998-2006 at 37 stations distributed throughout SF Bay. A correlation was discovered for all stations at (R2 =0.32), which improved markedly upon partitioning stations into north bay, (R2 =0.64), central bay (R2 =0.80) and south bay (R2 =0.52) regions. SSC was then compared from three USGS monitoring stations with temporally consistent Landsat 8 imagery. The resulting correlation between Landsat 8 (Rrs 654) and SSC measured at USGS stations (R2 =0.50) was validated using an Airborne Visible/ Infrared Imaging Spectrometer (AVIRIS) image. The end product is a two-step empirical algorithm that can derive PCB from Landsat 8 imagery within SF Bay. This algorithm can generate spatial PCB concentration maps for SF Bay, which can in turn be utilized to increase ability to forecast PCB concentration. The observation that correlation between AVIRIS (Rrs 657) and SSC was stronger than that of Landsat 8 suggests that the accuracy of this algorithm could be enhanced with improved atmospheric correction.

  10. Biomarker responsiveness in different tissues of caged Ruditapes philippinarum and its use within an integrated sediment quality assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Gomez, Julia, E-mail: julia.ramosgomez@uca.es [UNITWIN/UNESCO/WiCoP, Departamento de Quimica Fisica, Universidad de Cadiz, Facultad de Ciencias del Mar y Ambientales, Campus Universitario de Puerto Real, 11510 Puerto Real, Cadiz (Spain); Coz, Alberto; Viguri, Javier R. [Dpto. Ingenieria Quimica y Quimica Inorganica, ETSIIT, Universidad de Cantabria, Avda. los Castros, s/n 39005 Santander (Spain); Luque, Angel [Departamento de Biologia, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria, Gran Canaria, The Canary Islands (Spain); Martin-Diaz, M. Laura [UNITWIN/UNESCO/WiCoP, Departamento de Quimica Fisica, Universidad de Cadiz, Facultad de Ciencias del Mar y Ambientales, Campus Universitario de Puerto Real, 11510 Puerto Real, Cadiz (Spain); Centro Andaluz de Ciencia y Tecnologia Marinas (CACYTMAR), Universidad de Cadiz, Campus Universitario de Puerto Real, 11510 Puerto Real, Cadiz (Spain); DelValls, T. Angel [UNITWIN/UNESCO/WiCoP, Departamento de Quimica Fisica, Universidad de Cadiz, Facultad de Ciencias del Mar y Ambientales, Campus Universitario de Puerto Real, 11510 Puerto Real, Cadiz (Spain)

    2011-07-15

    Biomarkers comprising activities of biotransformation enzymes (ethoxyresorufin-O-deethylase -EROD-, dibenzylfluorescein dealkylase -DBF-, glutathione S-transferase -GST), antioxidant enzymes (glutathione reductase -GR- and glutathione peroxidase -GPX), lipid peroxidation -LPO- and DNA strand breaks were analyzed in the clam Ruditapes philippinarum caged at Cadiz Bay, Santander Bay and Las Palmas de Gran Canaria (LPGC) Port (Spain). Sediments were characterized. Digestive gland was the most sensitive tissue to sediment contamination. In Cadiz Bay, changes in LPO regarding day 0 were related with metals. In LPGC Port, DBF, EROD, and GST activity responses suggested the presence of undetermined contaminants which might have led to DNA damage. In Santander Bay, PAHs were related with EROD activity, organic and metal contamination was found to be associated with GR and GST activities and DNA damage presented significant (p < 0.05) induction. R. philippinarum was sensitive to sediment contamination at biochemical level. Biomarkers allowed chemical exposure and sediment quality assessment. - Highlights: > Ruditapes philippinarum is sensitive to sediment contamination at biochemical level. > Digestive gland biomarkers showed the best correlations with sediment contaminants. > Presence of potentially toxic chemicals not analyzed in this research was unmasked. > Multivariate analysis allowed the identification of toxic xenobiotic and possible sources. > Inner area of Santander Bay presented the highest sediment toxicity. - Integration of Ruditapes philippinarum biomarker results and sediment chemistry distinguished xenobiotic exposure and sediment toxicity in coastal areas of Spain.

  11. Structure and Composition of Mangrove Associations in Tubli Bay of Bahrain as Affected by Municipal Wastewater Discharge and Anthropogenic Sedimentation

    Directory of Open Access Journals (Sweden)

    Kholoud Abou Seedo

    2017-01-01

    Full Text Available The effects of municipal wastewater discharge and anthropogenic sedimentation on the structure and composition of gray mangrove (Avicennia marina (Forsk. Vierh. communities along Tubli Bay coastlines in Bahrain were investigated. Growth and regeneration of mangrove were measured, and its community was characterized. Sediment profile was analyzed for texture, pH, and salinity. Mangrove area covered by sand depositions was measured using Google Earth Pro. ANOVA and regression tests were employed in the analysis of the data. Results indicated that mangrove overwhelmingly dominated plant community in the study area, which was zoned by a community of other salt-tolerant species. Three main habitats exist in the study area with high similarity in their floristic composition. Species richness and the number of habitats were low due to the aridity and high sediment salinity. The dilution effect of the secondary treated wastewater had a favorable effect on height and diameters of mangrove trees. However, no differences were observed in leaf area index, basal area, and density of mangrove. The long-term accumulation of anthropogenic sedimentation had a detrimental effect on the mangrove community, expressed in swath death of mangrove trees due to root burials and formation of high topography within the community boundaries.

  12. Geochemistry and mineralogy of recent sediments of Guanabara Bay (NE sector and its major rivers - Rio de Janeiro State - Brazil

    Directory of Open Access Journals (Sweden)

    MARCIA DE MELO FARIA

    2001-03-01

    Full Text Available Geochemical and clay mineralogical studies of bottom sediments collected along the Macacu and Caceribu rivers and Guanabara Bay were carried out in order to investigate the relationship between major source areas and recent sediments of the bay. Clay mineralogy includes different groups with selective distribution conditioned by geomorphic features and depositional settings. Micaceous clay minerals are abundant near parent rock in the upper course, whereas kaolinite derived from varied sources is gradually concentrated towards the estuary. In the Guanabara Bay, kaolinite accumulates near river mouths, while micaceous clay minerals are converted into mixed layers in the estuary. Analyses of heavy metal contents reveal higher levels of Zn and Cu in sediments of the bay than in river sediments. Profiles along rivers indicate a downstream decrease of heavy metals, whereas in the bay geochemical trends display greater variations. In general river mouth sediments present the lowest concentrations. At the north and east of Paquetá Island anomalous areas with the highest heavy metal contents occur. Cu tends to concentrate in A correlação dos sedimentos recentes da Baía de Guanabara com as suas principais áreas-fontes foi realizada a partir de análises geoquímicas e de argilominerais em amostras de fundo coletadas ao longo dos rios Macacu e Caceribu e na baía. Os argilominerais indicam uma distribuição seletiva intimamente associada às características do relevo e aos ambientes deposicionais. Os argilominerais micáceos são predominantes na região do alto curso próximos à área-fonte primária, enquanto que a caulinita, proveniente da decomposição de diversos minerais, se concentra gradativamente em direção ao estuário. Na Baía de Guanabara observa-se um acúmulo de caulinita na região de foz dos rios, ao passo que os argilominerais micáceos são convertidos em interestratificados e depositados no fundo da baía. As análises geoqu

  13. Sediment grain sizes, Quaternary Ammonium Compounds (QACs), and others collected from RV Donald W Pritchard in Hempstead Bay, New York from 2013-02-11 to 2014-06-06 (NCEI Accession 0166078)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Measurements of sewage-derived compounds (qacs, which include personal care products) in grab samples of sediments of Hempstead Bay, NY, approximately 100 days to 20...

  14. Evaluation of dredged material proposed for ocean disposal from Red Hook/Bay Ridge project areas, New York

    Energy Technology Data Exchange (ETDEWEB)

    Pinza, M.R.; Barrows, E.S.; Borde, A.B. [Battelle/Marine Sciences Lab., Sequim, WA (United States)

    1996-09-01

    The objective of the Red HookIBay Ridge project was to evaluate proposed dredged material from these two areas to determine its suitability for unconfined ocean disposal at the Mud Dump Site. Sediment samples were collected from the Red Hook/Bay Ridge project areas. Tests and analyses were conducted. The evaluation of proposed dredged material from the Red Hook/Bay Ridge project areas consisted of bulk sediment chemical analyses, chemical analyses of dredging site water and elutriate, water-column and benthic acute toxicity tests. Twenty-four individual sediment core samples were collected from these two areas and analyzed for grain size, moisture content, and total organic carbon (TOC). Three composite sediment samples, representing Red Hook Channel and the two Bay Ridge Reaches to be dredged, were analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAH), and 1,4-dichlorobenzene. Dredging site water and elutriate water, which is prepared from the suspended-particulate phase (SPP) of the three Red Hook Bay Ridge sediment composites, were analyzed for metals, pesticides, and PCBS. Benthic acute toxicity tests were performed. Water-column or SPP toxicity tests were performed. Bioaccumulation tests were also conducted.

  15. Results of bulk sediment analysis and bioassay testing on selected sediments from Oakland Inner Harbor and Alcatraz disposal site, San Francisco, California

    International Nuclear Information System (INIS)

    Word, J.Q.; Ward, J.A.; Woodruff, D.L.

    1990-09-01

    The Battelle/Marine Sciences Laboratory (MSL) was contracted by the US Army Corps of Engineers, San Francisco District, to perform bulk sediment analysis and oyster larvae bioassays (elutriate) on sediments from Inner Oakland Harbor, California. Analysis of sediment characteristics by MSL indicated elevated priority pollutants, PAHs, pesticides, metals, organotins, and oil and grease concentrations, when compared to Alcatraz Island Dredged Material Disposal Site sediment concentrations. Larvae of the Pacific oyster, Crassostrea gigas, were exposed to seawater collected from the Alcatraz Island Site water, and a series of controls using water and sediments collected from Sequim Bay, Washington. Exposure of larvae to the Alcatraz seawater and the 50% and 100% elutriate concentrations from each Oakland sediment resulted in low survival and a high proportion of abnormal larvae compared to Sequim Bay control exposures. MSL identified that field sample collection, preservation, and storage protocols used by Port of Oakland contractors were inconsistent with standard accepted practices. 23 refs., 10 figs., 40 tabs

  16. Nelson River and Hudson Bay

    Science.gov (United States)

    2002-01-01

    Rivers that empty into large bodies of water can have a significant impact on the thawing of nearshore winter ice. This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from May 18, 2001, shows the Nelson River emptying spring runoff from the Manitoba province to the south into the southwestern corner of Canada's Hudson Bay. The warmer waters from more southern latitudes hasten melting of ice near the shore, though some still remained, perhaps because in shallow coastal waters, the ice could have been anchored to the bottom. High volumes of sediment in the runoff turned the inflow brown, and the rim of the retreating ice has taken on a dirty appearance even far to the east of the river's entrance into the Bay. The sediment would have further hastened the melting of the ice because its darker color would have absorbed more solar radiation than cleaner, whiter ice. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  17. Temporal fluctuations in grain size, organic materials and iron concentrations in intertidal surface sediment of San Francisco Bay

    Science.gov (United States)

    Thomson-Becker, E. A.; Luoma, S.N.

    1985-01-01

    The physical and chemical characteristics of the oxidized surface sediment in an estuary fluctuate temporally in response to physical forces and apparently-fluctuating inputs. These characteristics, which include grain size and concentrations of organic materials and iron, will influence both trace-metal geochemistry and bioavailability. Temporal trends in the abundance of fine particles, total organic carbon content (TOC), absorbance of extractable organic material (EOM), and concentration of extractable iron in the sediment of San Francisco Bay were assessed using data sets containing approximately monthly samples for periods of two to seven years. Changes in wind velocity and runoff result in monthly changes in the abundance of fine particles in the intertidal zone. Fine-grained particles are most abundant in the late fall/early winter when runoff is elevated and wind velocities are low; particles are coarser in the summer when runoff is low and wind velocities are consistently high. Throughout the bay, TOC is linearly related to fine particle abundance (r = 0.61). Temporal variability occurs in this relationship, as particles are poor in TOC relative to percent of fine particles in the early rainy season. Iron-poor particles also appear to enter the estuary during high runoff periods; while iron is enriched on particle surfaces in the summer. Concentrations of extractable iron and absorbance of EOM vary strongly from year to year. Highest absorbances of EOM occurred in the first year following the drought in 1976-77, and in 1982 and 1983 when river discharge was unusually high. Extractable-iron concentrations were also highest in 1976-77, but were very low in 1982 and 1983. ?? 1985 Dr W. Junk Publishers.

  18. Seasonal variations and sources of sedimentary organic carbon in Tokyo Bay

    International Nuclear Information System (INIS)

    Kubo, Atsushi; Kanda, Jota

    2017-01-01

    Total organic carbon (TOC), total nitrogen (TN) contents, their stable C and N isotope ratio (δ 13 C and δ 15 N), and chlorophyll a ([Chl a] sed ) of surface sediments were investigated monthly to identify the seasonal variations and sources of organic matter in Tokyo Bay. The sedimentary TOC (TOC sed ) and TN (TN sed ) contents, and the sedimentary δ 13 C and δ 15 N (δ 13 C sed and δ 15 N sed ) values were higher in summer than other seasons. The seasonal variations were controlled by high primary production in the water column and hypoxic water in the bottom water during summer. The fraction of terrestrial and marine derived organic matter was estimated by Bayesian mixing model using stable isotope data and TOC/TN ratio. Surface sediments in Tokyo Bay are dominated by marine derived organic matter, which accounts for about 69 ± 5% of TOC sed . - Highlights: • High values of sedimentary organic carbon and nitrogen were observed in summer. • Surface sediments in Tokyo Bay were dominated by marine derived organic matter which was estimated by Bayesian mixing model. • The most amount of terrestrial POC was deposited and degraded in Tokyo Bay before being discharged to the open ocean.

  19. Thecamoebians: occurrence and distribution in Iguape Bay/BTS – Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Cláudia Ferreira da Cruz

    2012-09-01

    Full Text Available The Iguape Bay (12º00’ – 13º00’S and 38º30’ – 39º30’ is an estuary located at the mouth of the Paraguaçu River, inside Todos os Santos Bay (BTS, in Bahia, Brazil. It is 30km downstream from the Pedra do Cavalo Dam, which is the second largest dam in Brazil. The water in Iguape Bay is influenced by ocean tides originating from the BTS and the discharge of the Paraguaçu River. The effects of the currents as well as the variation in the outflow from the Pedra do Cavalo Dam have intensified the natural stress of this paralic environment. The main goal of this study was to investigate the distribution of Thecamoeba species present in the bottom sediments of Iguape Bay, in order to produce data that can be used to interpret the processes operating in this ecologically complex environment. The density of the living and dead species of Thecamoeba was determined by the volume of sediment collected, and the diversity index, constancy, evenness and richness of Thecamoeba were calculated. Sedimentological analyses were also performed in order to classify sediment types in the selected profiles.

  20. Radionuclides and stable elements in the sediments of the Yesa Reservoir, Central Spanish Pyrenees

    Energy Technology Data Exchange (ETDEWEB)

    Navas, Ana; Gaspar, Leticia; Palazon, Leticia [Estacion Experimental Aula Dei (EEAD- CSIC), Zaragoza (Spain). Dept. of Soil and Water; Valero-Garces, Blas [Instituto Pirenaico de Ecologia (IPE-CSIC), Zaragoza (Spain)

    2011-09-15

    Purpose: The sediments accumulated in the Yesa Reservoir (Central Spanish Pyrenees) have greatly decreased its water storage capacity and are a major threat to the sustainability of water resources in the region. This study examines the contents of radionuclides and stable elements in the reservoir sediments and relates their variations with the sediment composition and local sedimentary dynamics, particularly flood frequency and intensity, which are responsible for changes in the main supply and distribution of radionuclides in the basin. Materials and methods: The sedimentary sequence accumulated in the Yesa Reservoir (471 Hm{sup 3}), which supplies water to ca. 1,000,000 people and for irrigation, was examined in two 4-m long sediment cores (Y1, Y2) and one profile (Y3) retrieved at its central part. In the sediments, radionuclide activities of {sup 238}U, {sup 226}Ra, {sup 232}Th, {sup 40}K, {sup 210}Pb and {sup 137}Cs were measured using a hyperpure Ge coaxial detector. The stable elements Mg, Ca, Sr, Ba, Cr, Cu, Mn, Fe, Al, Zn, Ni, Co, Pb, Li, K and Na were analysed by ICP-OES. Complementary analyses to characterize the sediments included: XRD in the profile, grain size distribution by laser equipment and the contents of organic matter, carbonates and the residual fraction by loss on ignition. Results and discussion: The variation in radionuclide activities is associated with grain size and sediment composition. The activity levels (becquerels per kilogram) ranged between 20 and 43 for{sup 238}U, 14 and 40 for {sup 226}Ra, 7 and 56 for {sup 210}Pb, 19 and 46 for Th{sup 232}, 1 and 48 for {sup 137}Cs and 185 and 610 for {sup 40}K. Enriched activity levels are associated with clayey and silty layers, and depleted levels with sandy layers. The levels of radionuclides and trace elements were significantly lower in the cores than in the profile because of its higher silicate content and the influence of inflow of spring mineral-rich waters. The correlations among

  1. A brief study on the imprints of seismo tectonic activities in the crust of central and southern Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, K.V.L.N.S.; Subrahmanyam, A; Subrahmanyam, V.; Murty, G.P.S.; Rao, K.M.

    .Previousresults indicate that IT Imprintsof seismo tectonicactivities inthe crustof pans of Bay of Bengal --~ . i' . " " "'. ,. Fig.S. Sarellirederil'ed gral'iry allomaly data of Hm' of BellRalsho'A'i1ll!the imprillls of cru.\\.talstructure alld glm'in' lows (After Salld.... - April 2007. Vol. XXVIII '\\10.1& 2 pp 55 to 62 A BRIEF STUDY ON IMPRINTS OF SEISMO TECTONIC ,\\CTIVITIES IN THE CRUST OF CENTRAL AND SOUTHERN BAY OF BENGAL K.V.L.N.S.Sarma,A.S. Subrahmanyam, V.Subrahmanyam, G.P.S. Murty and K. Mohana Rao Nationallll...

  2. Contaminant transport and accumulation in Massachusetts Bay and Boston Harbor; a summary of U.S. Geological Survey studies

    Science.gov (United States)

    Butman, Bradford; Bothner, Michael H.; Hathaway, J.C.; Jenter, H.L.; Knebel, H.J.; Manheim, F.T.; Signell, R.P.

    1992-01-01

    The U.S. Geological Survey (USGS) is conducting studies in Boston Harbor, Massachusetts Bay, and Cape Cod Bay designed to define the geologic framework of the region and to understand the transport and accumulation of contaminated sediments. The region is being studied because of environmental problems caused by the introduction of wastes for a long time, because a new ocean outfall (to begin operation in 1995) will change the location for disposal of treated Boston sewage from Boston Harbor into Massachusetts Bay, and because of the need to understand the transport of sediments and associated contaminants in order to address a wide range of management questions. The USGS effort complements and is closely coordinated with the research and monitoring studies supported by the Massachusetts Environmental Trust, the Massachusetts Bays Program, and by the Massachusetts Water Resources Authority. The USGS study includes (1) geologic mapping, (2) circulation studies, (3) long-term current and sediment transport observations, (4) measurements of contaminant inventories and rates of sediment mixing and accumulation, (5) circulation modeling, (6) development of a contaminated sediments data base, and (7) information exchange. A long-term objective of the program is to develop a predictive capability for sediment transport and accumulation.

  3. Tracking sediment through the Holocene: Determining anthropogenic contributions to a sediment-rich agricultural system, north-central USA

    Science.gov (United States)

    Gran, Karen; Belmont, Patrick; Finnegan, Noah

    2013-04-01

    Management and restoration of sediment-impaired streams requires quantification of sediment sources and pathways of transport. Addressing the role of humans in altering the magnitude and sources of sediment supplied to a catchment is notoriously challenging. Here, we explore how humans have amplified erosion in geomorphically-sensitive portions of the predominantly-agricultural Minnesota River basin in north-central USA. In the Minnesota River basin, the primary sources of sediment are classified generally as upland agricultural field vs. near-channel sources, with near-channel sources including stream banks, bluffs, and ravines. Using aerial lidar data, repeat terrestrial lidar scans of bluffs, ravine monitoring, historic air photo analyses, and sediment fingerprinting, we have developed a sediment budget to determine the relative importance of each source in a tributary to the Minnesota River, the Le Sueur River. We then investigate how these sources have changed through time, from changes evident over the past few decades to changes associated with valley evolution over the past 13,400 years. The Minnesota River valley was carved ~13,400 years ago through catastrophic drainage of glacial Lake Agassiz. As the Minnesota River valley incised, knickpoints have migrated upstream into tributaries, carving out deep valleys where the most actively eroding near-channel sediment sources occur. The modern sediment budget, closed for the time period 2000 to 2010, shows that the majority of the fine sediment load in the Le Sueur River comes from bluffs and other near-channel sources in the deeply-incised knick zone. Numerical modeling of valley evolution constrained by mapped and dated strath terraces cut into the glacial till presents an opportunity to compare the modern sediment budget to that of the river prior to anthropogenic modification. This comparison reveals a natural background or "pre-agriculture" rate of erosion from near-channel sources to be 3-5 times lower

  4. Acid-volatile sulfide and simultaneously extracted metals in surface sediments of the southwestern coastal Laizhou Bay, Bohai Sea: concentrations, spatial distributions and the indication of heavy metal pollution status.

    Science.gov (United States)

    Zhuang, Wen; Gao, Xuelu

    2013-11-15

    Surface sediments were collected from the coastal waters of southwestern Laizhou Bay and the rivers it connects with during summer and autumn 2012. The acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) were measured to assess the sediment quality. The results showed that not all sediments with [SEM]-[AVS]>0 were capable of causing toxicity because the organic carbon is also an important metal-binding phase in sediments. Suppose the sediments had not been disturbed and the criteria of US Environmental Protection Agency had been followed, heavy metals in this area had no adverse biological effects in both seasons except for few riverine samples. The major ingredient of SEM was Zn, whereas the contribution of Cd - the most toxic metal studied - to SEM was <1%. The distributions of AVS and SEM in riverine sediments were more easily affected by anthropogenic activity compared with those in marine sediments. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Tracing mercury pathways in Augusta Bay (southern Italy) by total concentration and isotope determination

    International Nuclear Information System (INIS)

    Bonsignore, M.; Tamburrino, S.; Oliveri, E.; Marchetti, A.; Durante, C.; Berni, A.; Quinci, E.; Sprovieri, M.

    2015-01-01

    The mercury (Hg) pollution of sediments is the main carrier of Hg for the biota and, subsequently, for the local fish consumers in Augusta Bay area (SE Sicily, Italy), a coastal marine system affected by relevant sewage from an important chlor-alkali factory. This relationship was revealed by the determination of Mass Dependent (MDF) and Mass Independent Fractionation (MIF) of Hg isotopes in sediment, fish and human hair samples. Sediments showed MDF but no MIF, while fish showed MIF, possibly due to photochemical reduction in the water column and depending on the feeding habitat of the species. Benthic and demersal fish exhibited MDF similar to that of sediments in which anthropogenic Hg was deposited, while pelagic organisms evidenced higher MDF and MIF due to photoreduction. Human hair showed high values of δ 202 Hg (offset of +2.2‰ with respect to the consumed fish) and Δ 199 Hg, both associated to fish consumption. - Highlights: • We report the Hg isotope ratios of sediments, fish and human hair in Augusta Bay. • Hg isotopes show mercury transfers from sediments to benthic and demersal fish. • MIF in fish appears to be driven by effect of photoreduction. • MIF in human hair is inherited by fish consumption. - The mercury (Hg) isotope composition of sediments, fish muscles and human hair has been investigated from the highly polluted Augusta Bay (SE Sicily, Italy)

  6. Biomarker responsiveness in different tissues of caged Ruditapes philippinarum and its use within an integrated sediment quality assessment

    International Nuclear Information System (INIS)

    Ramos-Gomez, Julia; Coz, Alberto; Viguri, Javier R.; Luque, Angel; Martin-Diaz, M. Laura; DelValls, T. Angel

    2011-01-01

    Biomarkers comprising activities of biotransformation enzymes (ethoxyresorufin-O-deethylase -EROD-, dibenzylfluorescein dealkylase -DBF-, glutathione S-transferase -GST), antioxidant enzymes (glutathione reductase -GR- and glutathione peroxidase -GPX), lipid peroxidation -LPO- and DNA strand breaks were analyzed in the clam Ruditapes philippinarum caged at Cadiz Bay, Santander Bay and Las Palmas de Gran Canaria (LPGC) Port (Spain). Sediments were characterized. Digestive gland was the most sensitive tissue to sediment contamination. In Cadiz Bay, changes in LPO regarding day 0 were related with metals. In LPGC Port, DBF, EROD, and GST activity responses suggested the presence of undetermined contaminants which might have led to DNA damage. In Santander Bay, PAHs were related with EROD activity, organic and metal contamination was found to be associated with GR and GST activities and DNA damage presented significant (p < 0.05) induction. R. philippinarum was sensitive to sediment contamination at biochemical level. Biomarkers allowed chemical exposure and sediment quality assessment. - Highlights: → Ruditapes philippinarum is sensitive to sediment contamination at biochemical level. → Digestive gland biomarkers showed the best correlations with sediment contaminants. → Presence of potentially toxic chemicals not analyzed in this research was unmasked. → Multivariate analysis allowed the identification of toxic xenobiotic and possible sources. → Inner area of Santander Bay presented the highest sediment toxicity. - Integration of Ruditapes philippinarum biomarker results and sediment chemistry distinguished xenobiotic exposure and sediment toxicity in coastal areas of Spain.

  7. Lignin phenols used to infer organic matter sources to Sepetiba Bay - RJ, Brasil

    Science.gov (United States)

    Rezende, C. E.; Pfeiffer, W. C.; Martinelli, L. A.; Tsamakis, E.; Hedges, J. I.; Keil, R. G.

    2010-04-01

    Lignin phenols were measured in the sediments of Sepitiba Bay, Rio de Janeiro, Brazil and in bedload sediments and suspended