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Sample records for pamlico river estuarine

  1. 77 FR 48431 - Safety Zone for Fireworks Display, Pamlico and Tar Rivers; Washington, NC

    Science.gov (United States)

    2012-08-14

    ... near the Pamlico and Tar Rivers to commemorate Beaufort County's 300th anniversary. The temporary... 1625-AA00 Safety Zone for Fireworks Display, Pamlico and Tar Rivers; Washington, NC AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on...

  2. MERIS Retrieval of Water Quality Components in the Turbid Albemarle-Pamlico Sound Estuary, USA

    Directory of Open Access Journals (Sweden)

    Hans W. Paerl

    2011-04-01

    Full Text Available Two remote-sensing optical algorithms for the retrieval of the water quality components (WQCs in the Albemarle-Pamlico Estuarine System (APES were developed and validated for chlorophyll a (Chl. Both algorithms were semi-empirical because they incorporated some elements of optical processes in the atmosphere, water, and air/water interface. One incorporated a very simple atmospheric correction and modified quasi-single-scattering approximation (QSSA for estimating the spectral Gordon’s parameter, and the second estimated WQCs directly from the top of atmosphere satellite radiance without atmospheric corrections. A modified version of the Global Meteorological Database for Solar Energy and Applied Meteorology (METEONORM was used to estimate directional atmospheric transmittances. The study incorporated in situ Chl data from the Ferry-Based Monitoring (FerryMon program collected in the Neuse River Estuary (n = 633 and Pamlico Sound (n = 362, along with Medium Resolution Imaging Spectrometer (MERIS satellite imagery collected (2006–2009 across the APES; providing quasi-coinciding samples for Chl algorithm development and validation. Results indicated a coefficient of determination (R2 of 0.70 and mean-normalized root-mean-squares errors (NRMSE of 52% in the Neuse River Estuary and R2 = 0.44 (NRMSE = 75 % in the Pamlico Sound—without atmospheric corrections. The simple atmospheric correction tested provided on performance improvements. Algorithm performance demonstrated the potential for supporting long-term operational WQCs satellite monitoring in the APES.

  3. 77 FR 37356 - Safety Zone for Fireworks Display, Pamlico River; Washington, NC

    Science.gov (United States)

    2012-06-21

    ... 1625-AA00 Safety Zone for Fireworks Display, Pamlico River; Washington, NC AGENCY: Coast Guard, DHS... life and property of the maritime public from the hazards posed by fireworks displays. This zone is... 300th Anniversary Celebration Fireworks. DATES: Comments and related material must be received by the...

  4. Shoreline erosion and decadal sediment accumulation in the Tar-Pamlico estuary, North Carolina, USA: A source-to-sink analysis

    Science.gov (United States)

    Eulie, Devon O.; Corbett, D. Reide; Walsh, J. P.

    2018-03-01

    Estuaries contain vital habitats and it is important to understand how these areas respond to human activities and natural processes such as sea-level rise and wave attack. As estuarine shorelines erode or become modified with hard structures, there is potential for significantly altering the availability of sediment and the filling of coastal systems. This study used a source-to-sink approach and quantified rates of shoreline erosion in the Tar-Pamlico sub-estuary, a tributary of the larger Albemarle-Pamlico Estuarine System (APES). The average shoreline change rate (SCR) determined using an end-point method was -0.5 ± 0.9 m yr-1 for the Tar-Pamlico. Incorporating bulk density estimates, this contributes 0.6 × 105 tons of fine sediment to the system annually, or after accounting for fluvial input, about 40% of the total sediment supply to the sub-estuary. The role of the Tar-Pamlico as a sink for these sediments was addressed using the radionuclide tracers 210Pb and 137Cs. Radionuclide activities and sediment accumulation rates identified several depositional regions, in particular in the middle of the estuary. Linear sediment accumulation rates ranged from 0.10 ± 0.02 to 0.38 ± 0.02 g cm-2 yr-1, and total storage of fine sediment in the system was 1.6 × 105 t yr-1. It was not possible to confidently discern a change in the rate of shoreline erosion or seabed accumulation. A preliminary budget for fine sediments (grain-size <63 μm) was then calculated to compare erosional sources with sedimentary sinks. Almost all (∼93.0%) of the fine sediment entering the system was accumulated and stored, while only about 7.0% was exported to Pamlico Sound.

  5. 33 CFR 334.410 - Albemarle Sound, Pamlico Sound, and adjacent waters, NC; danger zones for naval aircraft operations.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Albemarle Sound, Pamlico Sound... AND RESTRICTED AREA REGULATIONS § 334.410 Albemarle Sound, Pamlico Sound, and adjacent waters, NC; danger zones for naval aircraft operations. (a) Target areas—(1) North Landing River (Currituck Sound...

  6. Striped Bass Spawning in Non-Estuarine Portions of the Savannah River

    Energy Technology Data Exchange (ETDEWEB)

    Martin, D.; Paller, M.

    2007-04-17

    Historically, the estuarine portions of the Savannah River have been considered to be the only portion of the river in which significant amounts of striped bass (Morone saxatilis) spawning normally occur. A reexamination of data from 1983 through 1985 shows a region between River Kilometers 144 and 253 where significant numbers of striped bass eggs and larvae occur with estimated total egg production near that currently produced in the estuarine reaches. It appears possible that there are two separate spawning populations of striped bass in the Savannah River.

  7. The role of river flow and tidal asymmetry on 1-D estuarine morphodynamics

    NARCIS (Netherlands)

    Guo, L.; Van der Wegen, M.; Roelvink, J.A.; He, Q.

    2014-01-01

    Numerous research efforts have been devoted to understanding estuarine morphodynamics under tidal forcing. However, the impact of river discharge on estuarine morphodynamics is insufficiently examined. Inspired by the Yangtze Estuary, this work explores the morphodynamic impact of river discharge in

  8. VARIATIONS IN THE SPECTRAL PROPERTIES OF FRESHWATER AND ESTUARINE CDOM CAUSED BY PARTITIONING ONTO RIVER AND ESTUARINE SEDIMENTS

    Science.gov (United States)

    The optical properties and geochemical cycling of chromophoric dissolved organic matter (CDOM) are altered by its sorption to freshwater and estuarine sediments. Measured partition coefficients (Kp) of Satilla River (Georgia) and Cape Fear River estuary (North Carolina) CDOM ran...

  9. Financial Statement Audit Report of Pamlico Community College.

    Science.gov (United States)

    Campbell, Ralph

    This report presents the results of the Pamlico Community College financial statement audit for the fiscal year ending on June 30, 1998. Pamlico Community College is a component of the State of North Carolina, thus the authority to audit is granted by Article 5A of G.S. 147. The accounts and operations of the institution were subject to audit…

  10. Estuarine Response to River Flow and Sea-Level Rise under Future Climate Change and Human Development

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhaoqing; Wang, Taiping; Voisin, Nathalie; Copping, Andrea E.

    2015-04-01

    Understanding the response of river flow and estuarine hydrodynamics to climate change, land-use/land-cover change (LULC), and sea-level rise is essential to managing water resources and stress on living organisms under these changing conditions. This paper presents a modeling study using a watershed hydrology model and an estuarine hydrodynamic model, in a one-way coupling, to investigate the estuarine hydrodynamic response to sea-level rise and change in river flow due to the effect of future climate and LULC changes in the Snohomish River estuary, Washington, USA. A set of hydrodynamic variables, including salinity intrusion points, average water depth, and salinity of the inundated area, were used to quantify the estuarine response to river flow and sea-level rise. Model results suggest that salinity intrusion points in the Snohomish River estuary and the average salinity of the inundated areas are a nonlinear function of river flow, although the average water depth in the inundated area is approximately linear with river flow. Future climate changes will shift salinity intrusion points further upstream under low flow conditions and further downstream under high flow conditions. In contrast, under the future LULC change scenario, the salinity intrusion point will shift downstream under both low and high flow conditions, compared to present conditions. The model results also suggest that the average water depth in the inundated areas increases linearly with sea-level rise but at a slower rate, and the average salinity in the inundated areas increases linearly with sea-level rise; however, the response of salinity intrusion points in the river to sea-level rise is strongly nonlinear.

  11. Tracing Mississippi River influences in estuarine food webs of coastal Louisiana.

    Science.gov (United States)

    Wissel, Björn; Fry, Brian

    2005-08-01

    The Breton Sound estuary in southern Louisiana receives large amounts of Mississippi River water via a controlled diversion structure at the upstream end of the estuary. We used stable isotopes to trace spatial and seasonal responses of the downstream food web to winter and spring introductions of river water. Analysis of delta13C, delta15N, and delta34S in the common local consumers such as grass shrimp (Palaemonetes sp.), barnacles (Balanus sp.), and small plankton-feeding fish (bay anchovies, Anchoa mitchilli) showed that the diversion was associated with two of the five major source regimes that were supporting food webs: a river regime near the diversion and a river-influenced productive marsh regime farther away from the diversion. Mixing models identified a third river-influenced source regime at the marine end of the estuary where major natural discharge from the Bird's Foot Delta wraps around into estuarine waters. The remaining two source regimes represented typical estuarine conditions: local freshwater sources especially from precipitation and a brackish source regime representing higher salinity marine influences. Overall, the Mississippi River diversion accounted for 75% of food web support in the upper estuary and 25% in the middle estuary, with influence strongest along known flow pathways and closest to the diversion. Isotopes also traced seasonal changes in river contributions, and indicated increased plant community productivity along the major flow path of diversion water. In the Breton Sound estuary, bottom-up forcing of food webs is strongly linked to river introductions and discharge, occurring in spatial and temporal patterns predictable from known river input regimes and known hydrologic circulation patterns.

  12. How tides and river flows determine estuarine bathymetries [review article

    Science.gov (United States)

    Prandle, D.

    2004-04-01

    For strongly tidal, funnel-shaped estuaries, we examine how tides and river flows determine size and shape. We also consider how long it takes for bathymetric adjustment, both to determine whether present-day bathymetry reflects prevailing forcing and how rapidly changes might occur under future forcing scenarios. Starting with the assumption of a 'synchronous' estuary (i.e., where the sea surface slope resulting from the axial gradient in phase of tidal elevation significantly exceeds the gradient in tidal amplitude ζ̂), an expression is derived for the slope of the sea bed. Thence, by integration we derive expressions for the axial depth profile and estuarine length, L, as a function of ζ̂ and D, the prescribed depth at the mouth. Calculated values of L are broadly consistent with observations. The synchronous estuary approach enables a number of dynamical parameters to be directly calculated and conveniently illustrated as functions of ζ̂ and D, namely: current amplitude Û, ratio of friction to inertia terms, estuarine length, stratification, saline intrusion length, flushing time, mean suspended sediment concentration and sediment in-fill times. Four separate derivations for the length of saline intrusion, LI, all indicate a dependency on D 2/f ÛU o ( Uo is the residual river flow velocity and f is the bed friction coefficient). Likely bathymetries for `mixed' estuaries can be delineated by mapping, against ζ̂ and D, the conditions LI/ Lsalt. By combining the derived expressions for L and LI with this latter criterion, an expression is derived relating Di, the depth at the centre of the intrusion, to the corresponding value of Uo. This expression indicates Uo is always close to 1 cm s -1, as commonly observed. Converting from Uo to river flow, Q, provides a morphological expression linking estuarine depth to Q (with a small dependence on side slope gradients). These dynamical solutions are coupled with further generalised theory related to depth and

  13. Clay mineralogy and source-to-sink transport processes of Changjiang River sediments in the estuarine and inner shelf areas of the East China Sea

    Science.gov (United States)

    Zhao, Yifei; Zou, Xinqing; Gao, Jianhua; Wang, Chenglong; Li, Yali; Yao, Yulong; Zhao, Wancang; Xu, Min

    2018-02-01

    We examined the source-to-sink sediment transport processes from the Changjiang River to the estuarine coastal shelf area by analyzing the clay mineral assemblages in suspended sediment samples from the Changjiang River catchment and surface samples from the estuarine coastal shelf area following the impoundment of the Three Gorges Dam (TGD) in 2003. The results indicate that the clay mineral compositions throughout the study area are dominated by illite, with less abundant kaolinite and chlorite and scarce smectite. The clay minerals display distinct differences in the tributaries and exhibit obvious changes in the trunk stream compared with the periods before 2003, and the source of sediment has largely shifted to the mid- to lower reaches of the river after 2003. Spatially, the clay mineral assemblages in the estuarine area define two compositionally distinct provinces. Province I covers the mud area of the Changjiang River estuary and the Zhe-Min coastal region, where sediment is primarily supplied by the Changjiang River. Province II includes part of the Changjiang River estuary and the southeastern portion of the study area, where the sediment is composed of terrestrial material from the Changjiang River and re-suspended material from the Huanghe River carried by the Jiangsu coastal current. Moreover, the other smaller rivers in China (including the Oujiang and Minjiang rivers of mainland China and the rivers of West Taiwan) also contribut sediments to the estuarine and inner shelf areas. In general, the clay mineral assemblages in the Changjiang River estuarine area are have mainly been controlled by sediment supplied from upstream of the Changjiang River tributaries. However, since the completion of the TGD in 2003, the mid- to downstream tributaries have become the main source of sediments from the Changjiang catchment into the East China Sea. These analyses further demonstrate that the coastal currents and the decrease in the sediment load of the river

  14. Nutrient Dynamics of Estuarine Invertebrates Are Shaped by Feeding Guild Rather than Seasonal River Flow.

    Directory of Open Access Journals (Sweden)

    Kelly Ortega-Cisneros

    Full Text Available This study aimed to determine the variability of carbon and nitrogen elemental content, stoichiometry and diet proportions of invertebrates in two sub-tropical estuaries in South Africa experiencing seasonal changes in rainfall and river inflow. The elemental ratios and stable isotopes of abiotic sources, zooplankton and macrozoobenthos taxa were analyzed over a dry/wet seasonal cycle. Nutrient content (C, N and stoichiometry of suspended particulate matter exhibited significant spatio-temporal variations in both estuaries, which were explained by the variability in river inflow. Sediment particulate matter (%C, %N and C:N was also influenced by the variability in river flow but to a lesser extent. The nutrient content and ratios of the analyzed invertebrates did not significantly vary among seasons with the exception of the copepod Pseudodiaptomus spp. (C:N and the tanaid Apseudes digitalis (%N, C:N. These changes did not track the seasonal variations of the suspended or sediment particulate matter. Our results suggest that invertebrates managed to maintain their stoichiometry independent of the seasonality in river flow. A significant variability in nitrogen content among estuarine invertebrates was recorded, with highest % N recorded from predators and lowest %N from detritivores. Due to the otherwise general lack of seasonal differences in elemental content and stoichiometry, feeding guild was a major factor shaping the nutrient dynamics of the estuarine invertebrates. The nutrient richer suspended particulate matter was the preferred food source over sediment particulate matter for most invertebrate consumers in many, but not all seasons. The most distinct preference for suspended POM as a food source was apparent from the temporarily open/closed system after the estuary had breached, highlighting the importance of river flow as a driver of invertebrate nutrient dynamics under extreme events conditions. Moreover, our data showed that

  15. Nutrient Dynamics of Estuarine Invertebrates Are Shaped by Feeding Guild Rather than Seasonal River Flow.

    Science.gov (United States)

    Ortega-Cisneros, Kelly; Scharler, Ursula M

    2015-01-01

    This study aimed to determine the variability of carbon and nitrogen elemental content, stoichiometry and diet proportions of invertebrates in two sub-tropical estuaries in South Africa experiencing seasonal changes in rainfall and river inflow. The elemental ratios and stable isotopes of abiotic sources, zooplankton and macrozoobenthos taxa were analyzed over a dry/wet seasonal cycle. Nutrient content (C, N) and stoichiometry of suspended particulate matter exhibited significant spatio-temporal variations in both estuaries, which were explained by the variability in river inflow. Sediment particulate matter (%C, %N and C:N) was also influenced by the variability in river flow but to a lesser extent. The nutrient content and ratios of the analyzed invertebrates did not significantly vary among seasons with the exception of the copepod Pseudodiaptomus spp. (C:N) and the tanaid Apseudes digitalis (%N, C:N). These changes did not track the seasonal variations of the suspended or sediment particulate matter. Our results suggest that invertebrates managed to maintain their stoichiometry independent of the seasonality in river flow. A significant variability in nitrogen content among estuarine invertebrates was recorded, with highest % N recorded from predators and lowest %N from detritivores. Due to the otherwise general lack of seasonal differences in elemental content and stoichiometry, feeding guild was a major factor shaping the nutrient dynamics of the estuarine invertebrates. The nutrient richer suspended particulate matter was the preferred food source over sediment particulate matter for most invertebrate consumers in many, but not all seasons. The most distinct preference for suspended POM as a food source was apparent from the temporarily open/closed system after the estuary had breached, highlighting the importance of river flow as a driver of invertebrate nutrient dynamics under extreme events conditions. Moreover, our data showed that estuarine

  16. Geochemical studies of the river-estuarine systems of Krishna and Godavari

    International Nuclear Information System (INIS)

    Sarin, M.M.; Rao, K.S.; Bhattacharya, S.K.; Ramesh, R.; Somayajulu, B.L.K.

    1985-01-01

    During summer season, the Krishna river waters are enriched in major cations Na, K, Mg, Ca and Si by a factor of 1.2-1.9, in U by a factor of 3 and in delta D by 14.2per cent compared to those of Godavari. The high delta D of Krishna river waters (+ 1.6per cent) over those of Godavari (- 12.6per cent) indicate relatively more evaporation of the former by 15per cent. The uranium concentrations of Krishna waters at Vijayawada is 2.6 μ/l which decreases to 1.6 μ/l at Puligadda which is approx. 100 km downstream, whereas the 234 U/ 238 U activity ratio at both places is identical, 1.65 +- 0.03 suggesting authigenic removal of U in regions downstream of Vijayawada. Also, U does not appear to behave conservatively in the Krishna estuary as has been its behaviour in other Indian and some world rivers; there is removal of U from the Krishna estuarine waters. The major cations and delta D behave conservatively in both Krishna and Godavari estuaries. Si behaves almost conservatively in the Krishna estuary whereas in the Godavari estuary there is about 15per cent Si removal. The fluxes of all the measured constituents from Krishna and Godavari to the Bay of Bengal during the non-monsoon period are calculated. The clay, silt and and sand fractions as well as the Al, Fe, Mn, Cr and Ni concentrations of the clay fractions were determined in eight Krishna estuarine sediments and the results are discussed. The non-monsoonal clay, Al, Fe, Mn, Cr and Ni fluxes from Krishna river to the Bay of Bengal are also estimated. (author)

  17. Distribution of rare earth elements in the estuarine and coastal sediments of the Daliao River System, China

    International Nuclear Information System (INIS)

    Chunye Lin; Shaoqing Liu; Mengchang He; Ruiping Li

    2013-01-01

    The Daliao River System (DRS) estuary in Liaodong Bay features a highly industrial, urbanized, and agricultural catchment. The objective of this study was to determine the content, behavior, and distribution of the rare earth elements (REEs) in the estuarine and coastal sediments. To this end, 35 sediment samples were collected from the estuarine and coastal area and analyzed for REEs, Fe, Al, and Mn. The mean concentrations in mg kg -1 of the sediments were 33.4 (La), 64.1 (Ce), 7.9 (Pr), 29.0 (Nd), 5.4 (Sm), 1.2 (Eu), 4.2 (Gd), 0.78 (Tb), 4.0 (Dy), 0.84 (Ho), 2.3 (Er), 0.40 (Tm), 2.3 (Yb), and 0.37 (Lu). The REE concentrations in the sediments were significantly correlated with one another (r 2 = 0.959-0.988) and the concentrations of Fe, Al, and Mn (r 2 = 0.768-0.870). The total concentration ΣREE ranged from 73.5 to 203.5 mg kg -1 , with an average of 156.0 mg kg -1 being observed, and generally higher in the estuarine sediments than in the coastal sediments, most likely due to the salt-induced coagulation of river colloids and subsequently their accumulation at the estuarine bottom. The ratio of light REEs (ΣLREE) to heavy REEs (ΣHREE) was 9.4. Chondrite-normalized REE distributions were observed to be similar for the estuarine and coastal sediments, riverine suspended particles, and watershed soils of the DRS with higher LRRE enrichment than HREE and greater Eu depletion than Ce depletion. These results demonstrate that neither geochemical processes that carry soils to estuarine sediments nor long-term industrial and agricultural activities alter the distribution or fractionation of the REEs in the study area. (author)

  18. Assessing dissolved carbon transport and transformation along an estuarine river with stable isotope analyses

    Science.gov (United States)

    He, Songjie; Xu, Y. Jun

    2017-10-01

    Estuaries play an important role in the dynamics of dissolved carbon from rivers to coastal oceans. However, our knowledge of dissolved carbon transport and transformation in mixing zones of the world's coastal rivers is still limited. This study aims to determine how dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) concentrations and stable isotopes (δ13CDIC and δ13CDOC) change along an 88-km long estuarine river, the Calcasieu River in Louisiana, southern USA, with salinity ranging from 0.02 to 21.92. The study is expected to elucidate which processes most likely control carbon dynamics in a freshwater-saltwater mixing system, and to evaluate the net metabolism of this estuary. Between May 2015 and February 2016, water samples were collected and in-situ measurements on ambient water conditions were performed during five field trips at six sites from upstream to downstream of the Calcasieu River, which enters the Northern Gulf of Mexico (NGOM). The DIC concentration and δ13CDIC increased rapidly with increasing salinity in the mixing zone. The average DIC concentration and δ13CDIC at the site closest to the NGOM (site 6) were 1.31 mM and -6.34‰, respectively, much higher than those at the site furthest upstream (site 1, 0.42 mM and -20.83‰). The DIC concentrations appeared to be largely influenced by conservative mixing, while high water temperature may have played a role in deviating DIC concentration from the conservative line due likely to increased respiration and decomposition. The δ13CDIC values were close to those suggested by the conservative mixing model for May, June and November, but lower than those for July and February, suggesting that an estuarine river can fluctuate from a balanced to a heterotrophic system (i.e., production/respiration (P/R) aquatic photosynthesis from carbon produced by terrestrial photosynthesis in a river-ocean continuum.

  19. Implications of tidally-varying bed stress and intermittent estuarine stratification on fine-sediment dynamics through the Mekong's tidal river to estuarine reach

    Science.gov (United States)

    McLachlan, R. L.; Ogston, A. S.; Allison, M. A.

    2017-09-01

    River gauging stations are often located upriver of tidal propagation where sediment transport processes and storage are impacted by widely varying ratios of marine to freshwater influence. These impacts are not yet thoroughly understood. Therefore, sediment fluxes measured at these stations may not be suitable for predicting changes to coastal morphology. To characterize sediment transport dynamics in this understudied zone, flow velocity, salinity, and suspended-sediment properties (concentration, size, and settling velocity) were measured within the tidal Sông Hậu distributary of the lower Mekong River, Vietnam. Fine-sediment aggregation, settling, and trapping rates were promoted by seasonal and tidal fluctuations in near-bed shear stress as well as the intermittent presence of a salt wedge and estuary turbidity maximum. Beginning in the tidal river, fine-grained particles were aggregated in freshwater. Then, in the interface zone between the tidal river and estuary, impeded near-bed shear stress and particle flux convergence promoted settling and trapping. Finally, in the estuary, sediment retention was further encouraged by stratification and estuarine circulation which protected the bed against particle resuspension and enhanced particle aggregation. These patterns promote mud export ( 1.7 t s-1) from the entire study area in the high-discharge season when fluvial processes dominate and mud import ( 0.25 t s-1) into the estuary and interface zone in the low-discharge season when estuarine processes dominate. Within the lower region of the distributaries, morphological change in the form of channel abandonment was found to be promoted within minor distributaries by feedbacks between channel depth, vertical mixing, and aggregate trapping. In effect, this field study sheds light on the sediment trapping capabilities of the tidal river - estuary interface zone, a relatively understudied region upstream of where traditional concepts place sites of deposition

  20. Habitat and hydrology: assessing biological resources of the Suwannee River Estuarine System

    Science.gov (United States)

    Raabe, Ellen A.; Edwards, Randy E.; McIvor, Carole C.; Grubbs, Jack W.; Dennis, George D.

    2007-01-01

    The U.S. Geological Survey conducted a pilot integrated-science study during 2002 and 2003 to map, describe, and evaluate benthic and emergent habitats in the Suwannee River Estuary on the Gulf Coast of Florida. Categories of aquatic, emergent, and terrestrial habitats were determined from hyperspectral imagery and integrated with hydrologic data to identify estuarine fish habitats. Maps of intertidal and benthic habitat were derived from 12-band, 4-m resolution hyperspectral imagery acquired in September 2002. Hydrologic data were collected from tidal creeks during the winter of 2002-03 and the summer-fall of 2003. Fish were sampled from tidal creeks during March 2003 using rivulet nets, throw traps, and seine nets. Habitat characteristics, hydrologic data, and fish assemblages were compared for tidal creeks north and south of the Suwannee River. Tidal creeks north of the river had more shoreline edge and shallow habitat than creeks to the south. Tidal creeks south of the river were generally of lower salinity (fresher) and supported more freshwater marsh and submerged aquatic vegetation. The southern creeks tended to be deeper but less sinuous than the northern creeks. Water quality and inundation were evaluated with hydrologic monitoring in the creeks. In-situ gauges, recording pressure and temperature, documented a net discharge of brackish to saline groundwater into the tidal creeks with pronounced flow during low tide. Groundwater flow into the creeks was most prominent north of the river. Combined fish-sampling results showed an overall greater abundance of organisms and greater species richness in the southern creeks, nominally attributed a greater range in water quality. Fish samples were dominated by juvenile spot, grass shrimp, bay anchovy, and silverside. The short time frame for hydrologic monitoring and the one-time fish-sampling effort were insufficient for forming definitive conclusions. However, the combination of hyperspectral imagery and

  1. Herbicides from the Charente river and the estuarine zone (Marennes-Oleron) to the coastal seawater

    International Nuclear Information System (INIS)

    Scribe, P.; Chouakri, S.; Dupas, S.

    1999-01-01

    Spatial distribution of herbicides was investigated in the fluvial section, the estuary of the Charente river and the coastal zone (Marennes-Oleron). Monthly samplings were performed on a fluvial section from Angouleme to Saintes, at Chalonne, Nersac, Sireuil, Bourg and Brives from 1993 onwards. Estuarine and coastal sea-waters were sampled during two cruises in May 1991 and February 1992

  2. Observations of Lower Mississippi River Estuarine Dynamics: Effects of the Salt Wedge on Sediment Deposition

    Science.gov (United States)

    Ramirez, M. T.; Allison, M. A.

    2017-12-01

    The lowermost Mississippi River is subject to salt-wedge estuarine conditions during seasonally low flow, when seaward flow is unable to overcome density stratification. Previous studies in the Mississippi River salt wedge have shown the deposition of a fine sediment layer accumulating several mm/day beneath the reach where the salt wedge is present. Field studies were conducted during low flow in 2012-2015 utilizing ADCP, CTD, LISST, and physical samples to observe the physics of the salt wedge reach and to calculate rates and character of sediment trapping beneath the salt wedge. The field observations were summarized using a two-layer box-model representation of the reach to calculate water and sediment budgets entering, exiting, and stored within the reach. The salt wedge reach was found to be net depositional at rates up to 1.8 mm/day. The mechanism for transferring sediment mass from the downstream-flowing fluvial layer to the upstream-flowing marine layer appears to be flocculation, evidenced in LISST data by a spike in sediment particle diameters at the halocline. Applying reach-averaged rates of sediment trapping to a time-integrated model of salt-wedge position, we calculated annual totals ranging from 0.025 to 2.2 million tons of sediment deposited beneath the salt wedge, depending on salt-wedge persistence and upstream extent. Most years this seasonal deposit is remobilized during spring flood following the low-flow estuarine season, which may affect the timing of sediment delivery to the Gulf of Mexico, as well as particulate organic carbon, whose transport trajectory mirrors that of mineral sediment. These results are also relevant to ongoing dredging efforts necessary to maintain the economically-important navigation pathway through the lower Mississippi River, as well as planned efforts to use Mississippi River sedimentary resources to build land in the degrading Louisiana deltaic coast.

  3. Effects of hydrological forcing on the structure of a tropical estuarine food web

    Science.gov (United States)

    Trisha B. Atwood; Tracy N. Wiegner; Richard A. MacKenzie

    2012-01-01

    River flow can impact which sources of particulate organic matter (POM) fuel estuarine food webs. Here, we used stable carbon (C) and nitrogen (N) isotope analyses to compare how contributions of diff erent POM sources (terrestrial, estuarine, and marine) to the diets of zooplankton and juvenile fishes differed between low and high river flow conditions, as well as...

  4. Estuarine Landcover Along the Lower Columbia River Estuary Determined from Compact Ariborne Spectrographic Imager (CASI) Imagery, Technical Report 2003.

    Energy Technology Data Exchange (ETDEWEB)

    Garono, Ralph; Robinson, Rob

    2003-10-01

    Developing an understanding of the distribution and changes in estuarine and riparian habitats is critical to the management of biological resources in the lower Columbia River. In a recently completed comprehensive ecosystem protection and enhancement plan for the lower Columbia River Estuary (CRE), Jerrick (1999) identified habitat loss and modification as one of the key threats to the integrity of the CRE ecosystem. This management plan called for an inventory of habitats as key first step in the CRE long-term restoration effort. While previous studies have produced useful data sets depicting habitat cover types along portions of the lower CRE (Thomas, 1980; Thomas, 1983; Graves et al., 1995; NOAA, 1997; Allen, 1999), no single study has produced a description of the habitats for the entire CRE. Moreover, the previous studies differed in data sources and methodologies making it difficult to merge data or to make temporal comparisons. Therefore, the Lower Columbia River Estuary Partnership (Estuary Partnership) initiated a habitat cover mapping project in 2000. The goal of this project was to produce a data set depicting the current habitat cover types along the lower Columbia River, from its mouth to the Bonneville Dam, a distance of {approx}230-km (Fig. 1) using both established and emerging remote sensing techniques. For this project, we acquired two types of imagery, Landsat 7 ETM+ and Compact Airborne Spectrographic Imager (CASI). Landsat and CASI imagery differ in spatial and spectral resolution: the Landsat 7 ETM+ sensor collects reflectance data in seven spectral bands with a spatial resolution of 30-m and the CASI sensor collects reflectance data in 19 bands (in our study) with a spatial resolution of 1.5-m. We classified both sets of imagery and produced a spatially linked, hierarchical habitat data set for the entire CRE and its floodplain. Landsat 7 ETM+ classification results are presented in a separate report (Garono et al., 2003). This report

  5. 77 FR 31183 - Safety Zone, Temporary Change for Recurring Fireworks Display Within the Fifth Coast Guard...

    Science.gov (United States)

    2012-05-25

    ...-AA00 Safety Zone, Temporary Change for Recurring Fireworks Display Within the Fifth Coast Guard District, Pamlico River and Tar River; Washington, NC AGENCY: Coast Guard, DHS. ACTION: Temporary final... is intended to restrict vessel traffic in a portion of the Pamlico River and Tar River near...

  6. Estuarine consumers utilize marine, estuarine and terrestrial organic matter and provide connectivity among these food webs

    Science.gov (United States)

    The flux of organic matter (OM) across ecosystem boundaries can influence estuarine food web dynamics and productivity. However, this process is seldom investigated taking into account all the adjacent ecosystems (e.g. ocean, river, land) and different hydrological settings (i.e....

  7. Modeling the influence of river discharge on salt intrusion and residual circulation in Danshuei River estuary, Taiwan

    Science.gov (United States)

    Liu, W.-C.; Chen, W.-B.; Cheng, R.T.; Hsu, M.-H.; Kuo, A.Y.

    2007-01-01

    A 3-D, time-dependent, baroclinic, hydrodynamic and salinity model was implemented and applied to the Danshuei River estuarine system and the adjacent coastal sea in Taiwan. The model forcing functions consist of tidal elevations along the open boundaries and freshwater inflows from the main stream and major tributaries in the Danshuei River estuarine system. The bottom friction coefficient was adjusted to achieve model calibration and verification in model simulations of barotropic and baroclinic flows. The turbulent diffusivities were ascertained through comparison of simulated salinity time series with observations. The model simulation results are in qualitative agreement with the available field data. The validated model was then used to investigate the influence of freshwater discharge on residual current and salinity intrusion under different freshwater inflow condition in the Danshuei River estuarine system. The model results reveal that the characteristic two-layered estuarine circulation prevails most of the time at Kuan-Du station near the river mouth. Comparing the estuarine circulation under low- and mean flow conditions, the circulation strengthens during low-flow period and its strength decreases at moderate river discharge. The river discharge is a dominating factor affecting the salinity intrusion in the estuarine system. A correlation between the distance of salt intrusion and freshwater discharge has been established allowing prediction of salt intrusion for different inflow conditions. ?? 2007 Elsevier Ltd. All rights reserved.

  8. Estuarine Human Activities Modulate the Fate of Changjiang-derived Materials in Adjacent Seas

    Science.gov (United States)

    WU, H.

    2017-12-01

    Mega constructions have been built in many river estuaries, but their environmental consequences in the adjacent coastal oceans were often overlooked. This issue was addressed with an example of the Changjiang River Estuary, which was recently built with massive navigation and reclamation constructions in recent years. Based on the model validations against cruises data and the numerical scenario experiments, it is shown that the estuarine constructions profoundly affected the fates of riverine materials in an indeed large offshore area. This is because estuarine dynamics are highly sensitive to their bathymetries. Previously, the Three Gorges Dam (TGD) was thought to be responsible for some offshore environmental changes through modulating the river plume extension, but here we show that its influences are secondary. Since the TGD and the mega estuarine constructions were built during the similar period, their influences might be confused.

  9. Focus on CSIR research in water resources: conservation planning for river and estuarine biodiversity in the Fish to Tsitsikamma water management area

    CSIR Research Space (South Africa)

    Roux, D

    2007-08-01

    Full Text Available for river and estuarine biodiversity in the Fish- to-Tsitsikamma water management area Project Aims To put in practice and refine, through a pilot study in the Eastern Cape Province, the policy and planning tools developed for systematic conservation... engagement in developing the technical approach to river prioritization and selection, as well as the reviewing of results to facilitate buy-in and ownership of the product. Project Description The Fish to Tsitsikamma Water Management Area is one...

  10. Nutrient fluctuations in the Quatipuru river: A macrotidal estuarine mangrove system in the Brazilian Amazonian basin

    Science.gov (United States)

    Pamplona, Fábio Campos; Paes, Eduardo Tavares; Nepomuceno, Aguinaldo

    2013-11-01

    The temporal and spatial variability of dissolved inorganic nutrients (NO3-, NO2-, NH4+, PO43- and DSi), total nitrogen (TN), total phosphorus (TP), nutrient ratios, suspended particulate matter (SPM) and Chlorophyll-a (Chl-a) were evaluated for the macrotidal estuarine mangrove system of the Quatipuru river (QUATIES), east Amazon coast, North Brazil. Temporal variability was assessed by fortnightly sampling at a fixed station within the middle portion of the estuary, from November 2009 to November 2010. Spatial variability was investigated from two field surveys conducted in November 2009 (dry season) and May 2010 (rainy season), along the salinity gradient of the system. The average DIN (NO3- + NO2- + NH4+) concentration of 9 μM in the dry season was approximately threefold greater in comparison to the rainy season. NH4+ was the main form of DIN in the dry season, while NO3- predominated in the rainy season. The NH4+ concentrations in the water column during the dry season are largely attributed to release by tidal wash-out of the anoxic interstitial waters of the surficial mangrove sediments. On the other hand, the higher NO3- levels during the wet season, suggested that both freshwater inputs and nitrification processes in the water column acted in concert. The river PO43- concentrations (DIP mangrove forests also played a relevant role as a nutrient source as established by the high variability of the nutrient behaviour along the estuarine gradient, consequently affecting the productivity in QUATIES.

  11. Defense Coastal/Estuarine Research Program 2 (DCERP2)

    Science.gov (United States)

    2013-05-01

    Assessing TMDL effectiveness using flow-adjusted concentrations:  A case study of the Neuse River , North Carolina. Environmental Science & Technology 37...activities, and data collection in the NRE Basin and New River by local stakeholder groups. Defense Coastal/Estuarine Research Program (DCERP) Monitoring...relationships between light penetration and solids/chl a levels. ArcGIS and spatial statistics will be used to estimate average bathymetric areas

  12. The flux of 226Ra from estuarine and continental shelf sediments

    International Nuclear Information System (INIS)

    Li, Y.H.; Mathieu, G.; Biscaye, P.; Simpson, H.J.

    1977-01-01

    A pronounced desorption phenomenon of 226 Ra from sediment was observed in the Hudson River estuary. Mass balance calculations indicate that the desorption of 226 Ra from the river-borne sediment in estuarine environment is an important source of 226 Ra to the oceans. (Auth.)

  13. Resuspension and estuarine nutrient cycling: insights from the Neuse River Estuary

    Directory of Open Access Journals (Sweden)

    D. R. Corbett

    2010-10-01

    Full Text Available For at least the past several decades, North Carolina's Neuse River Estuary (NRE has been subject to water quality problems relating to increased eutrophication. Research initiated in the past several years have addressed the nutrient processes of the water column and the passive diffusion processes of the benthic sedimentary environment. Resuspension of bottom sediments, by bioturbation, tides, or winds, may also have a significant effect on the flux of nutrients in an estuarine system These processes can result in the advective transport of sediment porewater, rich with nitrogen, phosphorus and carbon, into the water column. Thus, estimates of nutrient and carbon inputs from the sediments may be too low.

    This study focused on the potential change in bottom water nutrient concentrations associated with measured resuspension events. Previous research used short-lived radionuclides and meteorological data to characterize the sediment dynamics of the benthic system of the estuary. These techniques in conjunction with the presented porewater inventories allowed evaluation of the depth to which sediments have been disturbed and the advective flux of nutrients to the water column. The largest removal episode occurred in the lower NRE as the result of a wind event and was estimated that the top 2.2 cm of sediment and corresponding porewater were removed. NH4+ advective flux (resuspended was 2 to 6 times greater than simply diffusion. Phosphate fluxes were estimated to be 15 times greater than the benthic diffusive flux. Bottom water conditions with elevated NH4+ and PO43− indicate that nutrients stored in the sediments continue to play an important role in overall water quality and this study suggests that the advective flux of nutrients to the water column is critical to understand estuarine nutrient cycling.

  14. Coastal and estuarine resources of Bangladesh: management and conservation issues

    Directory of Open Access Journals (Sweden)

    Abu Hena M. Kamal

    2009-07-01

    Full Text Available The coastal area of Bangladesh includes a number of bays into which different types of rivers empty, creating an estuarine ecosystem adjacent to the shore. The main estuarine systems are Brahmaputra-Megna (Gangetic delta, Karnaphuly, Matamuhuri, Bakkhali and Naf rivers, which are comprised of mangroves, salt marshes, seagrass, seaweeds, fisheries, coastal birds, animals, coral reefs, deltas, salt beds, minerals and sand dunes. The estuarine environment, which serves as feeding, breeding and nursery grounds for a variety of animals, varies according to the volume of discharge of the river and tidal range. It is highly productive in terms of nutrient input from different sources that promotes other living resources in the estuaries. Drought conditions exist during the winter months, i.e. November to February, and effective rainfall is confined to the monsoon period, i.e. May to June. Changes in salinity and turbidity depend on annual rainfall. The colour of most estuarine waters is tea brown or brown due to heavy outflows during the monsoon. The tidal mixing and riverine discharge governs the distribution of the hydrological parameters. The pH of these waters is reported to be slightly alkaline (>7.66 and dissolved oxygen (<6.0 mg/l shows an inverse relationship to temperature. Studies of plankton have indicated two periods of maximum abundance, i.e. February-March and August-September. The abundance of fish and shrimp larvae varies in number and composition with season. Many marine and freshwater species are available in various types of coastal brackish water, which depend on monsoonal activities and local environmental conditions.

  15. Environmental characteristics of the Mandovi-Zuari estuarine system in Goa

    Science.gov (United States)

    Qasim, S. Z.; Sen Gupta, R.

    1981-11-01

    Two rivers, the Mandovi and the Zuari, with their interconnecting canal, form an estuarine system in Goa on the west coast of India. Physical, chemical and biological features of this estuary are adapted to a seasonal rhythm induced by the annual cycle of the monsoon. Heavy precipitation and land runoff from June to September bring about large changes in temperature, salinity, flow pattern, dissolved oxygen and nutrients when the estuary becomes freshwater dominated. The monsoon season (July-September) is followed by a recovery period during the post-monsoon season (October-January) and thereafter a stable period of the pre-monsoon season (February-May) when the estuary becomes marine dominated. During the pre-monsoon (dry) season, the water in the estuarine system remains well mixed and the intrusion of salt water is felt as far as 65 km upstream in both the rivers; but during the monsoon season the rivers become stratified and a salt wedge is formed in each river which extends up to about 10 km upstream in the Mandovi and 12 km in the Zuari. The flow of the estuarine system is regulated by the entry of seawater with the incoming tide through Zuari which reaches Mandovi through the canal. The flow is reversed during the outgoing tide when the estuarine system is flushed. Dilution factors in both the estuaries are similar and vary from 1·2 to 8; highest values occur during the pre-monsoon season. Two shoals/sand bars occur permanently in Mandovi (Aguada Bay) close to a ramp-like inlet to the sea. This inlet poses no navigational problems for about 9 months during the dry season; but for a 3-month period during the monsoon, the waterway becomes hazardous and is closed to boat traffic. Heavy swell and intense wave activity lead to the transfer of sediments into the navigational inlet and the calm season brings the materials back to their original position with practically no overall change in the bathymetry of the bay. The oxygen cycle in the estuarine system is

  16. Climate Change and Migration along the Albemarle and Pamlico Sounds, North Carolina

    Science.gov (United States)

    Rummel, J. D.; Griffith, D. C.; Kimmel, D. G.; Landry, C. E.; Montz, B. E.

    2012-12-01

    Climactic events that have stimulated or enhanced human migrations have been documented historically. For example, the U.S. granted Temporary Protective Status to Honduran migrants following Hurricane Mitch in 1998, and many of those migrated to North Carolina and other parts of the U.S. South. In North Carolina and elsewhere, changing environmental conditions have led to shifting migration patterns among fish, birds, marine mammals, and other species—with a concomitant change in fishing practices and other forms of marine resource exploitation. Now, significant landscape changes are taking place as a result of global climate change, including sea level rise, changing ice cover at the poles, an increasing frequency and duration of drought, forest fires, and storms. Anthropocentric responses to the occasional disasters that will punctuate these changes suggest that the relationship between climate/environmental change and migration is likely to become central to the future of the geosciences along with the environmental and social sciences, as well as an essential focus to policies influencing population movements, environmental health, and risk management. Over the last two decades, the Albemarle-Pamlico region of North Carolina has harbored one of the nation's fastest growing populations, with immigrants to the region primarily consisting of two distinct, yet interconnected, groups: 1) relatively affluent U.S. citizens (including many retirees seeking proximity to coastal amenities); and, 2) relatively poor workers (many from Mexico and Central America) attracted to the region for work in agriculture, fisheries, food processing, construction/ landscaping, tourism, and forestry. By settling near the coast, these immigrants can be particularly susceptible to storm surge and other damage from the combination of sea level rise, hurricanes, and related processes that are reshaping coastal environments. This paper considers the past, present, and future of climate

  17. 33 CFR 334.412 - Albemarle Sound, Pamlico Sound, Harvey Point and adjacent waters, NC; restricted area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Albemarle Sound, Pamlico Sound, Harvey Point and adjacent waters, NC; restricted area. 334.412 Section 334.412 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA...

  18. Diversions of the Ribeira river flow and their Influence on Sediment Supply in the Cananeia-Iguape Estuarine-Lagoonal System (SE Brazil)

    Science.gov (United States)

    Cornaggia, Flaminia; Jovane, Luigi; Alessandretti, Luciano; Alves de Lima Ferreira, Paulo; Lopes Figueira, Rubens C.; Rodelli, Daniel; Bueno Benedetti Berbel, Gláucia; Braga, Elisabete S.

    2018-04-01

    The Cananéia-Iguape system is a combined estuarine-lagoonal sedimentary system, located along the SE coast of Brazil. It consists of a network of channels and islands oriented mainly parallel to the coast. About 165 years ago, an artificial channel, the Valo Grande, was opened in the northern part of this system to connect a major river of the region, the Ribeira River, to the estuarine-lagoon complex. The Valo Grande was closed with a dam and re-opened twice between 1978 and 1995, when it was finally left open. These openings and closures of the Valo Grande had a significant influence on the Cananéia-Iguape system. In this study we present mineralogical, chemical, palaeomagnetic, and geochronological data from a sediment core collected at the southern end of the 50-km long lagoonal system showing how the phases of the opening and closure of the channel through time are expressed in the sedimentary record. Despite the homogeneity of the grain size and magnetic properties throughout the core, significant variations in the mineralogical composition showed the influence of the opening of the channel on the sediment supply. Less mature sediment, with lower quartz and halite and higher kaolinite, brucite, and franklinite, corresponded to periods when the Valo Grande was open. On the other hand, higher abundance of quartz and halite, as well as the disappearance of other detrital minerals, corresponded with periods of absence or closure of the channel, indicating a more sea-influenced depositional setting. This work represented an example of anthropogenic influence in a lagoonal-estuarine sedimentary system, which is a common context along the coast of Brazil.

  19. Clay mineralogy indicates the muddy sediment provenance in the estuarine-inner shelf of the East China Sea

    Science.gov (United States)

    Zhao, Yifei; Zou, Xinqing; Liu, Qing; Wang, Chenglong; Ge, Chendong; Xu, Min

    2018-02-01

    The estuarine-inner shelf mud regions of the East China Sea (ECS) are valuable for studying the source-to-sink processes of fluvial sediments deposited since the Holocene. In this study, we present evidence of the provenance and environmental evolution of two cores (S5-2 and JC07) from the estuarine-inner shelf regions of the ECS over the past 100 years based on 210Pb dating, high-resolution grain size measurements and clay mineral analyses. The results indicate that the clay mineral assemblages of cores S5-2 and JC07 are dominated by illite, followed by kaolinite and chlorite, and present scarce amounts of smectite. A comparison of these clay mineral assemblages with several major sources reveals that the fine sediments on the estuarine-inner shelf of the ECS represent a mixture of provenances associated with the Yangtze and Yellow Rivers, as well as smaller rivers. However, the contribution of each provenance has varied greatly over the past hundred years, as indicated by the down-core variability due to strong sediment reworking and transport on the inner shelf and the reduction of the sediment load from the Yangtze River basin. In the mud region of the Yangtze River estuary, the sediment from 1930 to 1956 was primarily derived from the Yangtze River, although the Yellow River was also an important influence. From 1956 to 2013, the Yellow River contribution decreased, whereas the Yangtze River contribution correspondingly increased. In the Zhe-Min mud region, the Yangtze River contributed more sediment than did other rivers from 1910 to 1950; however, the Yangtze River contribution gradually decreased from 1950 to 2013. Moreover, the other small rivers accounted for minor contributions, and the East Asian winter monsoon (EAWM) played an important role in the sediment transport process in the ECS. Our results indicate that the weakening/strengthening of the EAWM and a decrease in the sediment load of the Yangtze River influenced the transport and fate of sediment

  20. The estuarine chemistry and isotope systematics of 234,238U in the Amazon and Fly Rivers

    Science.gov (United States)

    Swarzenski, P.; Campbell, P.; Porcelli, D.; McKee, B.

    2004-01-01

    Natural concentrations of 238U and ??234U values were determined in estuarine surface waters and pore waters of the Amazon and Fly (Papua New Guinea) Rivers to investigate U transport phenomena across river-dominated land-sea margins. Discharge from large, tropical rivers is a major source of dissolved and solid materials transported to the oceans, and are important in defining not only oceanic mass budgets, but also terrestrial weathering rates. On the Amazon shelf, salinity-property plots of dissolved organic carbon, pH and total suspended matter revealed two vastly contrasting water masses that were energetically mixed. In this mixing zone, the distribution of uranium was highly non-conservative and exhibited extensive removal from the water column. Uranium removal was most pronounced within a salinity range of 0-16.6, and likely the result of scavenging and flocculation reactions with inorganic (i.e., Fe/Mn oxides) and organic colloids/particles. Removal of uranium may also be closely coupled to exchange and resuspension processes at the sediment/water interface. An inner-shelf pore water profile indicated the following diagenetic processes: extensive (???1 m) zones of Fe(III) - and, to a lesser degree, Mn(IV) - reduction in the absence of significant S(II) concentrations appeared to facilitate the formation of various authigenic minerals (e.g., siderite, rhodocrosite and uraninite). The pore water dissolved 238U profile co-varied closely with Mn(II). Isotopic variations as evidenced in ??234U pore waters values from this site revealed information on the origin and history of particulate uranium. Only after a depth of about 1 m did the ??234U value approach unity (secular equilibrium), denoting a residual lattice bound uranium complex that is likely an upper-drainage basin weathering product. This suggests that the enriched ??234U values represent a riverine surface complexation product that is actively involved in Mn-Fe diagenetic cycles and surface

  1. The estuarine chemistry and isotope systematics of 234,238U in the Amazon and Fly Rivers

    Science.gov (United States)

    Swarzenski, Peter; Campbell, Pamela; Porcelli, Don; McKee, Brent

    2004-12-01

    Natural concentrations of 238U and δ234U values were determined in estuarine surface waters and pore waters of the Amazon and Fly (Papua New Guinea) Rivers to investigate U transport phenomena across river-dominated land-sea margins. Discharge from large, tropical rivers is a major source of dissolved and solid materials transported to the oceans, and are important in defining not only oceanic mass budgets, but also terrestrial weathering rates. On the Amazon shelf, salinity-property plots of dissolved organic carbon, pH and total suspended matter revealed two vastly contrasting water masses that were energetically mixed. In this mixing zone, the distribution of uranium was highly non-conservative and exhibited extensive removal from the water column. Uranium removal was most pronounced within a salinity range of 0-16.6, and likely the result of scavenging and flocculation reactions with inorganic (i.e., Fe/Mn oxides) and organic colloids/particles. Removal of uranium may also be closely coupled to exchange and resuspension processes at the sediment/water interface. An inner-shelf pore water profile indicated the following diagenetic processes: extensive (˜1 m) zones of Fe(III)—and, to a lesser degree, Mn(IV)—reduction in the absence of significant S(II) concentrations appeared to facilitate the formation of various authigenic minerals (e.g., siderite, rhodocrosite and uraninite). The pore water dissolved 238U profile co-varied closely with Mn(II). Isotopic variations as evidenced in δ234U pore waters values from this site revealed information on the origin and history of particulate uranium. Only after a depth of about 1 m did the δ234U value approach unity (secular equilibrium), denoting a residual lattice bound uranium complex that is likely an upper-drainage basin weathering product. This suggests that the enriched δ234U values represent a riverine surface complexation product that is actively involved in Mn-Fe diagenetic cycles and surface

  2. The impact of channel capture on estuarine hydro-morphodynamics and water quality in the Amazon delta.

    Science.gov (United States)

    Silva Dos Santos, Eldo; Pinheiro Lopes, Paula Patrícia; da Silva Pereira, Hyrla Herondina; de Oliveira Nascimento, Otávio; Rennie, Colin David; da Silveira Lobo O'Reilly Sternberg, Leonel; Cavalcanti da Cunha, Alan

    2018-05-15

    Due to progressive erosion of the new Urucurituba Channel, the Amazon River has recently captured almost all discharge from the lower Araguari River (Amapá-AP, Brazil), which previously flowed directly to the Atlantic Ocean. These recent geomorphological changes have caused strong impacts on the landscape and hydrodynamic patterns near the Araguari River mouth, especially the alteration of the riverine drainage system and its water quality. Landsat images were used to assess the estuarine landscape morphodynamic, particularly the expansion of the Urucurituba Channel, 80km from the Araguari River mouth, chronicling its connection to the Amazon River. The results suggest that the Urucurituba developed by headward migration across the Amazon delta; this is perhaps the first observation of estuarine distributary network development by headward channel erosion. The rate of Urucurituba Channel width increase has been ≈5m/month since 2011, increasing drainage capacity of the channel. We also collected in situ hydrodynamic measurements and analyzed 17 water quality parameters. Having 2011 as baseline, the flowrate of Araguari River has been diverted by up to 98% through Urucurituba Channel, with substantial changes in net discharge recorded at 3 monitoring stations. Statistically significant differences in water quality (pEstuarine salinity and solids concentrations have increased. Overall, we demonstrate changes in landscape, hydrodynamics and water quality of the lower Araguari River. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Predicting effects of environmental change on river inflows to ...

    Science.gov (United States)

    Estuarine river watersheds provide valued ecosystem services to their surrounding communities including drinking water, fish habitat, and regulation of estuarine water quality. However, the provisioning of these services can be affected by changes in the quantity and quality of river water, such as those caused by altered landscapes or shifting temperatures or precipitation. We used the ecohydrology model, VELMA, in the Trask River watershed to simulate the effects of environmental change scenarios on estuarine river inputs to Tillamook Bay (OR) estuary. The Trask River watershed is 453 km2 and contains extensive agriculture, silviculture, urban, and wetland areas. VELMA was parameterized using existing spatial datasets of elevation, soil type, land use, air temperature, precipitation, river flow, and water quality. Simulated land use change scenarios included alterations in the distribution of the nitrogen-fixing tree species Alnus rubra, and comparisons of varying timber harvest plans. Scenarios involving spatial and temporal shifts in air temperature and precipitation trends were also simulated. Our research demonstrates the utility of ecohydrology models such as VELMA to aid in watershed management decision-making. Model outputs of river water flow, temperature, and nutrient concentrations can be used to predict effects on drinking water quality, salmonid populations, and estuarine water quality. This modeling effort is part of a larger framework of

  4. Impact of estuarine gradients on reductive dechlorination of 1,2,3,4-tetrachlorodibenzo-p-dioxin in river sediment enrichment cultures.

    Science.gov (United States)

    Dam, Hang T; Häggblom, Max M

    2017-02-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) are among the most persistent organic pollutants. Although the total input of PCDDs into the environment has decreased substantially over the past four decades, their input via non-point sources is still increasing, especially in estuarine metropolitan areas. Here we report on the microbially mediated reductive dechlorination of PCDDs in anaerobic enrichment cultures established from sediments collected from five locations along the Hackensack River, NJ and investigate the impacts of sediment physicochemical characteristics on dechlorination activity. Dechlorination of 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TeCDD) and abundance of Dehalococcoides spp. negatively correlated with salinity and sulfate concentration in sediments used to establish the cultures. 1,2,3,4-TeCDD was dechlorinated to a lesser extent in cultures established from sediments from the tidally influenced estuarine mouth of the river. In cultures established from low salinity sediments, 1,2,3,4-TeCDD was reductively dechlorinated with the accumulation of 2-monochlorodibenzo-p-dioxin as the major product. Sulfate concentrations above 2 mM inhibited 1,2,3,4-TecDD dechlorination activity. Consecutive lateral- and peri- dechlorination took place in enrichment cultures with a minimal accumulation of 2,3-dichlorodibenzo-p-dioxin in active cultures. A Dehalococcoides spp. community was enriched and accounted for up to 64% of Chloroflexi detected in these sediment cultures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Simulating the indirect effects of power plant entrainment losses on an estuarine ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Summers, J.K. (Versar, Inc., Columbia, MD (USA))

    1989-12-01

    Entrainment caused by the operation of the Chalk Point Steam Electric Station has been shown to be a major source of mortality to the early life stages of forage fish populations in the Patuxent River, MD, USA. While direct losses to these populations are important as a source of reduction for population abundance, these losses also represent decreases in estuarine forage supplies and potential reductions in the abundances of estuarine predators. A simple estuarine trophic dynamics model was constructed to determine the magnitude of the potential losses to major estuarine consumers in the Patuxent River ecosystem due to the power plant-related losses of forage fish. Simulations were completed using two sets of feeding assumptions: feeding proportional to forage abundance, and feeding based on dietary preferences. The model demonstrates that striped bass, bluefish, and weakfish could experience significant losses (> 25%) to overall population production levels if they prefer to prey upon bay anchovy and silversides and entrainment losses to these forage populations is {>=} 70% of juvenile recruitment. The model also shows that indirect predator losses would be expected to be low (> 5%) if the majority of their diets consisted of forage other than bay anchovy and silversides. 2 figs., 31 refs., 4 tabs.

  6. Ecosystem variability along the estuarine salinity gradient: Examples from long-term study of San Francisco Bay

    Science.gov (United States)

    Cloern, James E.; Jassby, Alan D.; Schraga, Tara; Kress, Erica S.; Martin, Charles A.

    2017-01-01

    The salinity gradient of estuaries plays a unique and fundamental role in structuring spatial patterns of physical properties, biota, and biogeochemical processes. We use variability along the salinity gradient of San Francisco Bay to illustrate some lessons about the diversity of spatial structures in estuaries and their variability over time. Spatial patterns of dissolved constituents (e.g., silicate) can be linear or nonlinear, depending on the relative importance of river-ocean mixing and internal sinks (diatom uptake). Particles have different spatial patterns because they accumulate in estuarine turbidity maxima formed by the combination of sinking and estuarine circulation. Some constituents have weak or no mean spatial structure along the salinity gradient, reflecting spatially distributed sources along the estuary (nitrate) or atmospheric exchanges that buffer spatial variability of ecosystem metabolism (dissolved oxygen). The density difference between freshwater and seawater establishes stratification in estuaries stronger than the thermal stratification of lakes and oceans. Stratification is strongest around the center of the salinity gradient and when river discharge is high. Spatial distributions of motile organisms are shaped by species-specific adaptations to different salinity ranges (shrimp) and by behavioral responses to environmental variability (northern anchovy). Estuarine spatial patterns change over time scales of events (intrusions of upwelled ocean water), seasons (river inflow), years (annual weather anomalies), and between eras separated by ecosystem disturbances (a species introduction). Each of these lessons is a piece in the puzzle of how estuarine ecosystems are structured and how they differ from the river and ocean ecosystems they bridge.

  7. Modelling the effect of hydrological change on estuarine health: An Australian Perspective. (Invited)

    Science.gov (United States)

    Bruce, L. C.; Adiyanti, S.; Ruibal, A. L.; Hipsey, M. R.

    2013-12-01

    Estuaries provide an important role in the filtering and transformation of carbon and nutrients from coastal catchments into the marine environment. Global trends including climate change, increased population, industrialization and agriculture have led to the rapid deterioration of estuarine ecosystems across the world. Within the Australian context, a particular concern is how changes to hydrological regimes, due to both water diversions and climate variability, are contributing to increased stress and consequent decline in estuarine health. In this study we report the modeling output of five Australian estuaries, each with different hydrological regimes and alternative management issues relating to altered hydrology: 1) The Yarra River estuary is a highly urbanized system, also receiving agriculturally derived nutrients, where the concern is the role of periodic hypoxia in reducing the assimilation capacity of nitrogen and thus increased risk of algal blooms forming in the coastal environment; 2) The upper Swan River estuary in Western Australia, which experiences persistent anoxia and hypoxia brought about by reduced flows has led to the commissioning of several oxygenation plants to alleviate stress on biodiversity and overall estuarine health; 3) The health of the Caboolture estuary in Queensland has deteriorated in the past decade with the aim of model development to quantify the various sources of surface and groundwater derived nutrients; 4) The construction of an additional channel to increase flushing in the Peel Harvey estuary in Western Australia was designed to control persistent harmful algal blooms; and 5) The Lower River Murray estuary experienced a prolonged drought that led to the development of acid sulfate soils and acid drainage deteriorating water quality. For these applications we applied 3-D hydrodynamic-biogeochemical models to determine underlying relationships between altered flow regimes, increased temperatures and the response of

  8. Concentrations of stable elements and uranium in estuarine areas of Japan

    International Nuclear Information System (INIS)

    Takata, Hyoe; Aono, Tatsuo; Tagami, Keiko; Uchida, Shigeo

    2008-01-01

    The geochemistry of stable elements can be a good analogue for understanding the behavior of radionuclides in estuarine and coastal environments. In this study, the behavior of nutrients (NO 3 + NO 2 , PO 4 , Si(OH) 4 ), heavy metals, and U was observed in several estuarine and coastal waters of Japan. We also collected data on salinity, pH, and suspended particle matter (SPM). Nutrient concentrations followed conservative dilution lines in these estuaries, and concentrations of dissolved Fe decreased as salinity increased from 0 to 20. In general, most of the dissolved Fe in estuaries is in colloidal form. The behavior of dissolved Fe might reflect a loss of colloidal Fe through coagulation in this salinity range. Dissolved Co and Ni concentrations followed approximate dilution lines from the rivers to the seawater end-members, suggesting that they were quasi-conservative in these estuarine systems. A rapid increase in dissolved Cd concentrations was observed at low levels of salinity (<4). Estimated fluxes of dissolved Cd to the estuarine and coastal waters showed that the salt-induced desorption of Cd from particles constitutes a significant source of dissolved Cd in the estuarine and coastal waters. (author)

  9. MICROBIAL DIVERSITY IN SURFACE SEDIMENTS: A COMPARISON OF TWO ESTUARINE CONTINUUMS

    Science.gov (United States)

    The microbial diversity in estuarine sediments of the Altamaha and Savannah Rivers in Georgia were compared temporally and spatially using phospholipid fatty acid (PLFA) analysis. Surface sediment samples collected along a salinity gradient were also analyzed for ATP, TOC, and C ...

  10. Changes in assimilation of C3 marsh plants by resident fishes in estuarine systems with distinct hydrogeomorphology features.

    Directory of Open Access Journals (Sweden)

    Adna Ferreira Garcia

    2015-11-01

    Full Text Available Although saltmarshes are widely recognized as important habitats providing shelter for estuarine organisms and protection against predators, there is still no consensus on the trophic value of marsh plants for estuarine food webs. We employed stable isotopes to evaluate differences in assimilation of nutrients derived from marsh plants with C3 (Juncus acutus, Scirpus maritimus, Scirpus olneyi and C4 (Spartina densiflora photosynthetic pathways by resident fishes in three estuaries with contrasting hydrogeomorphology characteristics. Carbon (δ13C and nitrogen (δ15N stable isotope ratios of basal food sources (C3 and C4 marsh plants, macroalgae, seagrass and seston and estuarine resident fishes (Achirus garmani, Atherinella brasiliensis, Genidens genidens, Ctenogobius shufeldti, Jenynsia multidentata, Odonthestes argentinensis were analyzed in two choked lagoons (Tramandai-29°S, Patos-30°S and a coastal river (Chui-33°S. Average δ13C values of consumers were statistically significant higher in the two choked-type estuaries (Tramandaí: -16.11; Patos: -15.82 than in the coastal river (Chui: -24.32 (p0.292. SIAR mixing models revealed that the most assimilated basal food sources by consumers in the choked-type lagoon estuaries were a pool of 13C enriched food sources (macroalgae, C4 marsh and seagrass and seston (95% credibility interval: 0.38 to 0.80 and 0.00 to 0.54, respectively. In contrast, nutrients derived from C3-marsh plants were the main basal food source assimilated by estuarine resident fishes at the coastal river (0.33 to 0.87. These findings could be explained by the absence of extensive shallow embayments and a steeper slope at the coastal river that could promote higher transport of C3-marsh detritus and, consequently, higher assimilation by estuarine fishes. In contrast, detritus derived from C3 marsh plants could be trapped in the upper intertidal zone of choked-typed estuaries and, consequently, be less available for aquatic

  11. Brachyuran crab diversity of lower estuarine mud flats of Mahi River with new record of two species from Gujarat, India

    Directory of Open Access Journals (Sweden)

    P. J. Pandya

    2013-12-01

    Full Text Available A systematic study of brachyuran crab diversity and distribution was carried out for two years on the lower estuarine mud flats of the Mahi River, the upper Gulf of Khambhat, Gujarat. A total of 10 brachyuran crab species belonging to eight genera and eight families were identified. Study documented the distribution and habitat preference of the reported species on the intertidal area. The study records the occurance of two species Dotilla intermedia and Macrophthalmus brevis, for the first time from Gujarat. Moreover the study briefed on the habitat preference, general ethology and morphometry of new recorded species.

  12. River runoff influences on the Central Mediterranean overturning circulation

    Science.gov (United States)

    Verri, Giorgia; Pinardi, N.; Oddo, P.; Ciliberti, S. A.; Coppini, G.

    2018-03-01

    The role of riverine freshwater inflow on the Central Mediterranean Overturning Circulation (CMOC) was studied using a high-resolution ocean model with a complete distribution of rivers in the Adriatic and Ionian catchment areas. The impact of river runoff on the Adriatic and Ionian Sea basins was assessed by a twin experiment, with and without runoff, from 1999 to 2012. This study tries to show the connection between the Adriatic as a marginal sea containing the downwelling branch of the anti-estuarine CMOC and the large runoff occurring there. It is found that the multiannual CMOC is a persistent anti-estuarine structure with secondary estuarine cells that strengthen in years of large realistic river runoff. The CMOC is demonstrated to be controlled by wind forcing at least as much as by buoyancy fluxes. It is found that river runoff affects the CMOC strength, enhancing the amplitude of the secondary estuarine cells and reducing the intensity of the dominant anti-estuarine cell. A large river runoff can produce a positive buoyancy flux without switching off the antiestuarine CMOC cell, but a particularly low heat flux and wind work with normal river runoff can reverse it. Overall by comparing experiments with, without and with unrealistically augmented runoff we demonstrate that rivers affect the CMOC strength but they can never represent its dominant forcing mechanism and the potential role of river runoff has to be considered jointly with wind work and heat flux, as they largely contribute to the energy budget of the basin. Looking at the downwelling branch of the CMOC in the Adriatic basin, rivers are demonstrated to locally reduce the volume of Adriatic dense water formed in the Southern Adriatic Sea as a result of increased water stratification. The spreading of the Adriatic dense water into the Ionian abyss is affected as well: dense waters overflowing the Otranto Strait are less dense in a realistic runoff regime, with respect to no runoff experiment, and

  13. Abiotic characteristics and microalgal dynamics in South Africa's largest estuarine lake during a wet to dry transitional phase

    Science.gov (United States)

    Nunes, Monique; Adams, Janine B.; Bate, Guy C.; Bornman, Thomas G.

    2017-11-01

    The summer of 2012/2013 signified the end of the dry phase in the St Lucia estuarine system that lasted for over a decade. The increased rainfall coupled with the partial re-connection of the Mfolozi River to the estuarine system shifted St Lucia to a new limnetic state. With the increased availability of habitat due to the higher water level, it was expected that microalgal biomass and abundance would rapidly increase through recruitment from refuge areas i.e. South Lake and new introductions. Microalgal and physico-chemical data were collected at three sites within the Mfolozi/Msunduzi River and at 23 sites within the St Lucia estuarine system between June 2014 and February 2015. Results from this study indicated low biomass for both phytoplankton (<5 μg l-1) and microphytobenthos (<60 mg m-2) because of local and external drivers. These included limited nutrient and light availability, variable water residence times, biomass dilution and heterogeneity of the sediment. The high spatio-temporal variability limits the effectiveness of using the microalgal communities to detect change in the estuarine lake. In addition, significant intrasystem differences were observed between the three main lake basins and Narrows, due to the influence of the freshwater input from the Mfolozi River. This study provides insight into the spatio-temporal variability of physico-chemical conditions and microalgal communities during the 2014-2015 limnetic state.

  14. Microbial degradation of petroleum hydrocarbons in estuarine sediment of Tama River in Tokyo urban area

    International Nuclear Information System (INIS)

    Yamane, Akiko; Hosomi, Masaaki; Murakami, Akihiko; Sakakibara, Koji

    1997-01-01

    Aerobic and anaerobic biodegradation rates of petroleum hydrocarbons, i.e., hexadecane (HEX), phenanthrene (PHE), and anthracene (ANT), were determined in estuarine sediment of the Tama River in urban Tokyo, followed by estimating their respective degradation potential. While in a sediment slurry, the aerobic biodegradation rates of these petroleum hydrocarbons ranged from 40 to 70 μg.g -1 dry sediment:day -1 . The anaerobic biodegradation rate of HEX was found to be 5 -8 μg.g -1 dry sediment.day -1 , whereas that of PHE and ANT could not be detected following a 2-month incubation. Aerobic degradation of HEX was not affected by coexistence with either PHE or ANT, nor by the salinity level. The number of HEX-, PHE-, or ANT-utilizing bacteria ranged from 5 - 10% of the total number of aerobic heterotrophic bacteria. We calculated their biodegradation potentials using the biomass of naturally existing petroleum hydrocarbon utilizing bacteria present in the sampled sediment, with results for HEX, PHE, and ANT being 1.0 -3.5, 4.2 x 10 -2 , and 1.2 x 10 -2 -9.4 x 10 -1 μg.g -1 dry sediment day -1 , respectively. In the aerobic tidal sediment of the Tama River, the purification potentials of HEX, PHE, and ANT were assessed to be approximately equal to their accumulation potentials occurring at the normal water level. (Author)

  15. Development of an estuarine assessment scheme for the management of a highly urbanised catchment/estuary system, Sydney estuary, Australia.

    Science.gov (United States)

    Birch, G F; Gunns, T J; Chapman, D; Harrison, D

    2016-05-01

    As coastal populations increase, considerable pressures are exerted on estuarine environments. Recently, there has been a trend towards the development and use of estuarine assessment schemes as a decision support tool in the management of these environments. These schemes offer a method by which complex environmental data is converted into a readily understandable and communicable format for informed decision making and effective distribution of limited management resources. Reliability and effectiveness of these schemes are often limited due to a complex assessment framework, poor data management and use of ineffective environmental indicators. The current scheme aims to improve reliability in the reporting of estuarine condition by including a concise assessment framework, employing high-value indicators and, in a unique approach, employing fuzzy logic in indicator evaluation. Using Sydney estuary as a case study, each of the 15 sub-catchment/sub-estuary systems were assessed using the current scheme. Results identified that poor sediment quality was a significant issue in Blackwattle/Rozelle Bay, Iron Cove and Hen and Chicken Bay while poor water quality was of particular concern in Duck River, Homebush Bay and the Parramatta River. Overall results of the assessment scheme were used to prioritise the management of each sub-catchment/sub-estuary assessed with Blackwattle/Rozelle Bay, Homebush Bay, Iron Cove and Duck River considered to be in need of a high priority management response. A report card format, using letter grades, was employed to convey the results of the assessment in a readily understood manner to estuarine managers and members of the public. Letter grades also provide benchmarking and performance monitoring ability, allowing estuarine managers to set improvement targets and assesses the effectiveness of management strategies. The current assessment scheme provides an effective, integrated and consistent assessment of estuarine health and

  16. Tidal-Fluvial and Estuarine Processes in the Lower Columbia River: II. Water Level Models, Floodplain Wetland Inundation, and System Zones

    Energy Technology Data Exchange (ETDEWEB)

    Jay, David A.; Borde, Amy B.; Diefenderfer, Heida L.

    2016-04-26

    Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) are influenced by tides, river flow, hydropower operations, and coastal processes. In Part II, regression models based on tidal theory are used to quantify the role of these processes in determining water levels in the mainstem river and floodplain wetlands, and to provide 21-year inundation hindcasts. Analyses are conducted at 19 LCRE mainstem channel stations and 23 tidally exposed floodplain wetland stations. Sum exceedance values (SEVs) are used to compare wetland hydrologic regimes at different locations on the river floodplain. A new predictive tool is introduced and validated, the potential SEV (pSEV), which can reduce the need for extensive new data collection in wetland restoration planning. Models of water levels and inundation frequency distinguish four zones encompassing eight reaches. The system zones are the wave- and current-dominated Entrance to river kilometer (rkm) 5; the Estuary (rkm-5 to 87), comprised of a lower reach with salinity, the energy minimum (where the turbidity maximum normally occurs), and an upper estuary reach without salinity; the Tidal River (rkm-87 to 229), with lower, middle, and upper reaches in which river flow becomes increasingly dominant over tides in determining water levels; and the steep and weakly tidal Cascade (rkm-229 to 234) immediately downstream from Bonneville Dam. The same zonation is seen in the water levels of floodplain stations, with considerable modification of tidal properties. The system zones and reaches defined here reflect geological features and their boundaries are congruent with five wetland vegetation zones

  17. Large wood in the Snowy River estuary, Australia

    Science.gov (United States)

    Hinwood, Jon B.; McLean, Errol J.

    2017-02-01

    In this paper we report on 8 years of data collection and interpretation of large wood in the Snowy River estuary in southeastern Australia, providing quantitative data on the amount, sources, transport, decay, and geomorphic actions. No prior census data for an estuary is known to the authors despite their environmental and economic importance and the significant differences between a fluvial channel and an estuarine channel. Southeastern Australian estuaries contain a significant quantity of large wood that is derived from many sources, including river flood flows, local bank erosion, and anthropogenic sources. Wind and tide are shown to be as important as river flow in transporting and stranding large wood. Tidal action facilitates trapping of large wood on intertidal bars and shoals; but channels are wider and generally deeper, so log jams are less likely than in rivers. Estuarine large wood contributes to localised scour and accretion and hence to the modification of estuarine habitat, but in the study area it did not have large-scale impacts on the hydraulic gradients nor the geomorphology.

  18. Vertical distribution of elements in non-polluted estuarine sediments determined by neutron induced prompt gamma-ray and instrumental neutron activation analyses

    International Nuclear Information System (INIS)

    Kuno, A.; Sampei, K.; Matsuo, M.; Sawahata, H.

    1999-01-01

    Neutron induced prompt gamma-ray analysis (PGA) and instrumental neutron activation analysis (INAA) have been applied to the sediments collected from the Yasaka River estuary in Oita Prefecture, Japan. The vertical distribution of 33 elements in the sediments has been determined and compared with that in more polluted estuarine sediments. While the S content increased with increasing depth because of a sulphide accumulation under reducing condition, the increase in sulphide-forming elements such as Ag, Cd, Co and Zn was not observed in the deeper section of the Yasaka River estuarine sediments. (author)

  19. Reverse Estuarine Circulation Due to Local and Remote Wind Forcing, Enhanced by the Presence of Along-Coast Estuaries

    Science.gov (United States)

    Giddings, S. N.; MacCready, P.

    2017-12-01

    Estuarine exchange flow governs the interaction between oceans and estuaries and thus plays a large role in their biogeochemical processes. This study investigates the variability in estuarine exchange flow due to offshore oceanic conditions including upwelling/downwelling, and the presence of a river plume offshore (from a neighboring estuary). We address these processes via numerical simulations at the mouth of the Salish Sea, a large estuarine system in the Northeast Pacific. An analysis of the Total Exchange Flow indicates that during the upwelling season, the exchange flow is fairly consistent in magnitude and oriented in a positive (into the estuary at depth and out at the surface) direction. However, during periods of downwelling favorable winds, the exchange flow shows significantly more variability including multiple reversals, consistent with observations, and surface intrusions of the Columbia River plume which originates 250 km to the south. Numerical along-strait momentum budgets show that the exchange flow is forced dominantly by the pressure gradients, particularly the baroclinic. The pressure gradient is modified by Coriolis and sometimes advection, highlighting the importance of geostrophy and local adjustments. In experiments conducted without the offshore river plume, reversals still occur but are weaker, and the baroclinic pressure gradient plays a reduced role. These results suggest that estuaries along strong upwelling coastlines should experience significant modulation in the exchange flow during upwelling versus downwelling conditions. Additionally, they highlight the importance of nearby estuaries impacting one-another, not only in terms of connectivity, but also altering the exchange flow.Plain Language SummaryEstuarine systems provide extensive biological and ecological functions as well as contribute to human uses and economies. However, estuaries are susceptible to change and most estuaries have been significantly impacted, threatening

  20. Shock, stress or signal? Implications of freshwater flows for a top-level estuarine predator.

    Directory of Open Access Journals (Sweden)

    Matthew D Taylor

    Full Text Available Physicochemical variability in estuarine systems plays an important role in estuarine processes and in the lifecycles of estuarine organisms. In particular, seasonality of freshwater inflow to estuaries may be important in various aspects of fish lifecycles. This study aimed to further understand these relationships by studying the movements of a top-level estuarine predator in response to physicochemical variability in a large, temperate south-east Australian estuary (Shoalhaven River. Mulloway (Argyrosomus japonicus, 47-89 cm total length were surgically implanted with acoustic transmitters, and their movements and migrations monitored over two years via fixed-position VR2W acoustic receivers configured in a linear array along the length of the estuary. The study period included a high degree of abiotic variability, with multiple pulses (exponentially high flows over a short period of time in fresh water to the estuary, as well as broader seasonal variation in flow, temperature and conductivity. The relative deviation of fish from their modal location in the estuary was affected primarily by changes in conductivity, and smaller fish (n = 4 tended to deviate much further downstream from their modal position in the estuary than larger fish (n = 8. High-flow events which coincided with warmer temperatures tended to drive mature fish down the estuary and potentially provided a spawning signal to stimulate aggregation of adults near the estuary mouth; however, this relationship requires further investigation. These findings indicate that pulse and press effects of freshwater inflow and associated physicochemical variability play a role in the movements of mulloway, and that seasonality of large freshwater flows may be important in spawning. The possible implications of river regulation and the extraction of freshwater for consumptive uses on estuarine fishes are discussed.

  1. Influence of estuarine processes on spatiotemporal variation in bioavailable selenium

    Science.gov (United States)

    Stewart, Robin; Luoma, Samuel N.; Elrick, Kent A.; Carter, James L.; van der Wegen, Mick

    2013-01-01

    Dynamic processes (physical, chemical and biological) challenge our ability to quantify and manage the ecological risk of chemical contaminants in estuarine environments. Selenium (Se) bioavailability (defined by bioaccumulation), stable isotopes and molar carbon-tonitrogen ratios in the benthic clam Potamocorbula amurensis, an important food source for predators, were determined monthly for 17 yr in northern San Francisco Bay. Se concentrations in the clams ranged from a low of 2 to a high of 22 μg g-1 over space and time. Little of that variability was stochastic, however. Statistical analyses and preliminary hydrodynamic modeling showed that a constant mid-estuarine input of Se, which was dispersed up- and down-estuary by tidal currents, explained the general spatial patterns in accumulated Se among stations. Regression of Se bioavailability against river inflows suggested that processes driven by inflows were the primary driver of seasonal variability. River inflow also appeared to explain interannual variability but within the range of Se enrichment established at each station by source inputs. Evaluation of risks from Se contamination in estuaries requires the consideration of spatial and temporal variability on multiple scales and of the processes that drive that variability.

  2. Particulate organic matter predicts bacterial productivity in a river dominated estuary

    Science.gov (United States)

    Crump, B. C.

    2015-12-01

    Estuaries act as coastal filters for organic and inorganic fluvial materials in which microbial, biogeochemical, and ecological processes combine to transform organic matter and nutrients prior to export to the coastal ocean. The function of this estuarine 'bioreactor' is linked to the residence times of those materials and to rates of microbial heterotrophic activity. Our ability to forecast the impact of global change on estuarine bioreactor function requires an understanding of the basic controls on microbial community activity and diversity. In the Columbia River estuary, the microbial community undergoes a dramatic seasonal shift in species composition during which a spring bacterioplankton community, dominated by Flavobacteriaceae and Oceanospirillales, is replaced by a summer community, dominated by Rhodobacteraceae and several common marine taxa. This annual shift occurs in July, following the spring freshet, when river flow and river chlorophyll concentration decrease and when estuarine water residence time increases. Analysis of a large dataset from 17 research cruises (1990-2014) showed that the composition of particulate organic matter in the estuary changes after the freshet with decreasing organic carbon and nitrogen content, and increasing contribution of marine and autochthonous estuarine organic matter (based on PO13C and pigment ratios). Bacterial production rates (measured as leucine or thymidine incorporation rates) in the estuary respond to this change, and correlate strongly with labile particulate nitrogen concentration and temperature during individual sampling campaigns, and with the concentration of chlorophyll in the Columbia River across all seasons. Regression models suggest that the concentration of labile particulate nitrogen and the rate of bacterial production can be predicted from sensor measurements of turbidity, salinity, and temperature in the estuary and chlorophyll in the river. These results suggest that the quality of

  3. Suspended matter and bottom deposits in the Mahury estuarine system (French Guiana): Environmental consequences

    Science.gov (United States)

    Jouanneau, J. M.; Pujos, M.

    As part of a study carried out on the major rivers in French Guiana to identify and estimate the respective share of local rivers in the sedimentation of estuaries and the inshore continental shelf, results are reported on the Mahury after 2 periods of fieldwork carried out during one dry and one rainy season. The specific characteristics of the whole Mahury fluvio-estuarine system can be summed up as follows: the sands have invariable annual characteristics; they show evidence of a long history, first marine, then continental and finally fluviatile. They play little part in sedimentation on the continental shelf, and what part they do play is limited to the beaches. The fine sediments too have invariable annual characteristics. They fall, if we consider their mineralogical and elemental composition, on either side of a limit separating the fluviatile and estuarine zones. Here, the sediment stocks are respectively authigenic and allothogenic, while the clay association and elemental composition in the latter zone are evidence of an Amazonian origin. The contribution of the Mahury (Comté-Orapu) to fine estuarine sedimentation thus appears at present to be a very limited one, the Amazon being predominant over vast coastal areas, including the French Guiana estuaries.

  4. Climate induced variability of suspended matter and nutrient in the discharge of Kali river, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Raghavan, B.R.; Chauhan, O.S.

    to understand the influence of the SWM precipitation on estuarine and coastal processes. The seasonal discharge data of the river is obtained during 2004, which was a normal monsoon year. We find high nutrient load in the rivers, specially in the estuarine...

  5. Ecology of Estuarine Macrobenthos

    NARCIS (Netherlands)

    Herman, P.M.J.; Middelburg, J.J.; Koppel, J. van de; Heip, C.H.R.

    1999-01-01

    Macrobenthos is an important component of estuarine ecosystems. Based on a cross-system comparison, we show that estuarine macrobenthos may directly process a significant portion of the system-wide primary production, and that estuarine macrobenthic biomass may be predicted from primary production

  6. Distribution and flux of 226Ra and 228Ra in the Amazon River estuary

    International Nuclear Information System (INIS)

    Key, R.M.; Sarmiento, J.L.; Stallard, R.F.; Moore, W.S.

    1985-01-01

    Measurements of 226 Ra and 228 Ra in the Amazon River estuary show that desorption from riverborne suspended particulate matter in the estuary increases the riverine flux of both isotopes to the ocean by a factor of approximately 5 over the flux attributable to radium dissolved in the river water alone. The total Amazon flux supplies approximately 0.20% of the 226 Ra and approximately 2.6% of the 228 Ra standing crops in the near-surface Atlantic (0-200 m). Diffusive flux from estuarine and shelf sediments and desorption from resuspended sediments in the region of the estuary approximately double the estuarine 226 Ra concentration and quadruple the estuarine 228 Ra concentration above that caused by the dissolved and desorbed river components alone

  7. Redistribution of sewage-nitrogen in estuarine food webs following sewage treatment upgrades

    International Nuclear Information System (INIS)

    Pitt, Kylie A.; Connolly, Rod M.; Maxwell, Paul

    2009-01-01

    Stable nitrogen isotopes were used to assess the effects of wastewater treatment plant (WWTP) upgrades on the utilisation of sewage-N by estuarine biota in Moreton Bay, Australia. We measured δ 15 N of filamentous algae, mangrove leaves and shore crabs at the Brisbane and Logan Rivers before and after scheduled WWTP upgrades, and at two reference rivers where WWTPs had been upgraded >4 years previously. The total N discharged into Brisbane River decreased by >80% after the upgrades had occurred, but N loads remained similar at Logan River despite the upgrade. In Brisbane River, δ 15 N values of algae and crabs decreased and were comparable to the reference rivers within 1-2 years but no changes occurred at Logan River. The δ 15 N of mangrove leaves remained elevated in all rivers, indicating that sewage-N remained a major source to mangroves either from residual WWTP discharges or from N accumulated in the sediments over many years.

  8. Processing of humic-rich riverine dissolved organic matter by estuarine bacteria: effects of predegradation and inorganic nutrients

    DEFF Research Database (Denmark)

    Asmala, E.; Autio, R.; Kaartokallio, H.

    2014-01-01

    The bioavailability of predegraded dissolved organic matter (DOM) from a humic-rich, boreal river to estuarine bacteria from the Baltic Sea was studied in 39-day bioassays. The river waters had been exposed to various degrees of bacterial degradation by storing them between 0 and 465 days in dark...... prior to the bioassay. The resulting predegraded DOM was inoculated with estuarine bacteria and the subsequent changes in DOM quantity and quality measured. During the incubations, dissolved organic carbon (DOC) and oxygen concentrations decreased, indicating heterotrophic activity. Coloured DOM...... was degraded less than DOC, indicating a selective utilization of DOM, and humic-like fluorescence components increased during the incubations. The amount of DOC degraded was not affected by the length of DOM predegradation. The percentage of bioavailable DOC (%BDOC) was higher in experiment units with added...

  9. Estuarine morphodynamic adaptation to sediment supply and human activities : A case study of turbidity maximum

    NARCIS (Netherlands)

    Zhu, C.; Guo, L; Tian, B.; He, Q; Wang, Zhengbing

    2017-01-01

    Estuarine morphodynamics undergo significant changes due to declined sediment supply from river, rising sea-level, and human interferences (Syvitski and Saito, 2007; Syvitski et al., 2009). The Yangtze Estuary is such a case whose decadal morphodynamic evolution was broadly examined. It was

  10. Occurrence of quaternary ammonium compounds (QACs) and their application as a tracer for sewage derived pollution in urban estuarine sediments

    International Nuclear Information System (INIS)

    Li, Xiaolin; Luo, Xiaojun; Mai, Bixian; Liu, Jingqin; Chen, Li; Lin, Shanshan

    2014-01-01

    Particle reactive organic contaminants in estuarine sediments can lead to various environmental problems affecting ecosystem and public health. In this study, the occurrence and homologous distribution pattern of quaternary ammonium compounds (QACs) in the surficial sediments collected from the Pearl River Estuary (PRE), China were examined along with polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs). The composition pattern of the QACs was found to be uniform in most of the sediments analyzed throughout the PRE, and the average composition pattern was identical to that determined in the sewage sludge from Guangzhou, the biggest city in the PRE. Dialkyldimethylammonium compounds, the most abundant type of QACs, positively correlated to the total concentrations of PCBs and PBDEs in most of the sediments with similar composition patterns. Therefore, the QACs are proposed as potential tracers to evaluate the transport of sewage-derived pollution in estuarine environments. -- Highlights: • Analysis method is developed for quaternary ammonium compounds (QACs) in sediment. • Occurrence of QACs is observed in the Pearl River Estuary, China for the first time. • QACs are proposed to be a tracer for sewage derived pollution in estuarine sediment. -- QACs were found to be present in the estuarine sediments in China for the first time and proposed as potential tracers for sewage-derived pollution in urban estuary

  11. Impact of silver nanoparticles on benthic prokaryotes in heavy metal-contaminated estuarine sediments in a tropical environment.

    Science.gov (United States)

    Antizar-Ladislao, B; Bhattacharya, B D; Ray Chaudhuri, S; Sarkar, S K

    2015-10-15

    Little knowledge is available about the potential impact of commercial silver nanoparticles (Ag-NPs) on estuarine microbial communities. The Hugli river estuary, India, is susceptible to heavy metals pollution through boat traffic, and there is the potential for Ag-NP exposure via effluent discharged from ongoing municipal and industrial activities located in close proximity. This study investigated the effects of commercial Ag-NPs on native microbial communities in estuarine sediments collected from five stations, using terminal restriction fragment length polymorphism (T-RFLP) technique. An increase in the number of bacteria in consortium in sediments was observed following exposure to Ag-NPs. In general microbial communities may be resistant in estuarine systems to the antimicrobial effects of commercial Ag-NPs, but key microorganisms, such as Pelobacter propionicus, disappeared following exposure to Ag-NPs. In conclusion, the T-RFLP analysis indicated that Ag-NPs have the potential to shape estuarine sediment bacterial community structure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Columbia River ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species in Columbia River. Vector polygons in this...

  13. Determination of the total concentration and speciation of metal ions in river, estuarine and seawater samples.

    Science.gov (United States)

    Alberti, Giancarla; Biesuz, Raffaela; Pesavento, Maria

    2008-12-01

    Different natural water samples were investigated to determine the total concentration and the distribution of species for Cu(II), Pb(II), Al(III) and U(VI). The proposed method, named resin titration (RT), was developed in our laboratory to investigate the distribution of species for metal ions in complex matrices. It is a competition method, in which a complexing resin competes with natural ligands present in the sample to combine with the metal ions. In the present paper, river, estuarine and seawater samples, collected during a cruise in Adriatic Sea, were investigated. For each sample, two RTs were performed, using different complexing resins: the iminodiacetic Chelex 100 and the carboxylic Amberlite CG50. In this way, it was possible to detect different class of ligands. Satisfactory results have been obtained and are commented on critically. They were summarized by principal component analysis (PCA) and the correlations with physicochemical parameters allowed one to follow the evolution of the metals along the considered transect. It should be pointed out that, according to our findings, the ligands responsible for metal ions complexation are not the major components of the water system, since they form considerably weaker complexes.

  14. Long-term fluctuations in population of Semibalanus balanoides (L. (Crustacea in the estuarine zone of the Kola Bay

    Directory of Open Access Journals (Sweden)

    Svitina V. S.

    2017-06-01

    Full Text Available The intertidal population of the barnacles Semibalanus balanoides has been explored in the estuarine zone of the Tuloma River at the end of the Kola Bay for the first time. Barnacles S. balanoides are typical species for the littoral zone of the northern seas, they populate both the high and low salinity areas along the coast of the Barents Sea. The ecology and distribution of barnacle population in estuarine intertidal zones of the Barents Sea are not studied previously, and under the critical salinity conditions of any estuary, in particular. The investigation have been carried out on the littoral of the western (left shore of the southern tribe of the Kola Bay – the estuary section from the Tuloma bridge to the Cape Elovy. The studied site is a sandy-boulder beach with stony bars, its length is about 1 150 m, the area is about 126 500 m2. Counting the number of S. balanoides in clusters has been performed on site (without removal of the copepods from the population by the standard method for intertidal sampling. Simultaneously with the defining the number of barnacles for the period 2003–2014, the measurements of salinity and temperature of water and air have been made. The peculiarity of the estuarine barnacle population is their complete absence in the upper horizon of the littoral, and in the middle and the lower horizons they are found only within the channels of the littoral streams (3–20 specimens in the sample. For the first time the abundance and biomass of barnacles S. balanoides in this estuarine population has been determined, and the causes of their narrow-local distribution on the estuary littoral of the Tuloma River have been revealed. The main ecological factors determining the abundance and specific distribution of barnacles under the conditions of estuarine littoral have been established. The regular increase in the density of adult S. balanoides settlements along the gradient of water salinity from the Tuloma River to

  15. Ecotoxicological water assessment of an estuarine river from the Brazilian Northeast, potentially affected by industrial wastewater discharge.

    Science.gov (United States)

    de Melo Gurgel, Piatã; Navoni, Julio Alejandro; de Morais Ferreira, Douglisnilson; do Amaral, Viviane Souza

    2016-12-01

    Water pollution generated by industrial effluents discharge is a threat to the maintenance of aquatic ecosystems and human development. The Jundiai River estuarine, located in Northeast Brazil, receives an industrial pretreated effluent load from the city of Macaíba/RN/Brazil. The present study aimed to assess the water quality of this water reservoir through i) physicochemical characterization, ii) quantification of metal concentration and iii) by an ecotoxicological assessment carried out using Mysidopsis juniae and Pomacea lineata. The study was performed throughout the period comprising May to September 2014. Physicochemical variables such as chloride, total solids and electrical conductivity presented values in the waste discharge point, significantly different with those located out of the waste releasing point. Apart from that, metal concentration showed variable behavior throughout the monitored period. Levels of Al, Fe, Cu, Cd, Cr, Ni, Pb and Ag were over the considered guidelines. Both natural and anthropogenic sources seem to be involved in the resulting environmental scenario. A reduction in the fecundity rate (using Mysidopsis juniae) along with an increase in mortality rate (in both species) was observed ratifying the presence of toxic substances in this water reservoir. Moreover, a correlation analysis stated an association of the aforementioned toxicological effects with the delivery of industrial waste products. The ecotoxicological assessment performed highlighted the presence of toxic substance/s in water from the Jundiai River. Especially as a consequence of industrial activity, a fact that might threaten the bioma and, therefore, the human health of the population settled in the studied region. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Environmental management of estuarine areas: a proposal for conservation of water and biodiversity to the mangroves of the Paraiba do Sul River estuary, Gargaú, RJ

    Directory of Open Access Journals (Sweden)

    Edêmea Faria Carlos Rocha

    2016-12-01

    Full Text Available Being impacted by illegal occupation and untreated sewage release, the mangrove estuary of the Paraíba do Sul River has high biodiversity and provides various ecosystem services. In this study, we focused on strategies for sustainability promotion in Gargaú, a locality in this estuarine region, associating mangrove conservation to the uses of common resources practiced by locals. The main investigated issues were: “Would it be feasible to create a Conservation Unit in order to reinforce legal mechanisms to protect the mangrove?”; and “How does the local community see the scenario of environmental degradation and the proposal of creating a Conservation Unit in the region?”. Locals strongly depend on the estuarine area resources and perceive mangrove deforestation as well as untreated sewage release as the main causes of negative impacts. Despite not knowing what a Conservation Unit actually is, local key informants agreed to its creation after clarification of the categories and groups fixed by Brazilian legislation. Although accepting it with reservation, they understood it is a necessary measure to conserve the mangrove that sustains them.

  17. Runoff, discharge and flood occurrence in a poorly gauged tropical basin : the Mahakam River, Kalimantan

    NARCIS (Netherlands)

    Hidayat, H.

    2013-01-01

    Tidal rivers and lowland wetlands present a transition region where the interests of hydrologists and physical oceanographers overlap. Physical oceanographers tend to simplify river hydrology, by often assuming a constant river discharge when studying estuarine dynamics. Hydrologists, in turn,

  18. Seasonal variability of planktonic copepods (Copepoda: Crustacea in a tropical estuarine region in Brazil

    Directory of Open Access Journals (Sweden)

    Cristina de Oliveira Dias

    2009-12-01

    Full Text Available The Caravelas River estuary and adjacent coastal region were studied during the rainy and dry seasons of 2003-2004 to assess the copepod community structure. Abiotic and biotic parameters were measured, and the total density, frequency and percentage of copepod taxa were determined for each sampling period. Copepod densities showed significant differences between sampling periods, with higher densities in the rainy seasons (Mean: 90,941.80 ind.m-3; S.D.: 26,364.79. The sampling stations located to the north and south, in the coastal region adjacent to the Caravelas River estuary presented the lowest copepod density values. The copepod assemblage was composed mainly of estuarine and estuarine/coastal copepods. The seasonal variations in temperature and salinity influenced the abundance of species during the rainy and dry seasons, with the following dominant species alternating: Paracalanus quasimodo Bowman, 1971 in the rainy season of 2003, Parvocalanus crassirostris Dahl, 1894 in the dry season of 2003 and Acartia lilljeborgii Giesbrecht, 1892 in the rainy and dry seasons of 2004. Non-parametric multidimensional scaling indicated differences in copepod assemblages between sampling periods, but not between sampling stations.

  19. Efficiencies of freshwater and estuarine constructed wetlands for phenolic endocrine disruptor removal in Taiwan.

    Science.gov (United States)

    Hsieh, Chi-Ying; Yang, Lei; Kuo, Wen-Chien; Zen, Yi-Peng

    2013-10-01

    We examined the distribution and removal efficiencies of phenolic endocrine disruptors (EDs), namely nonylphenol diethoxylates (NP2EO), nonylphenol monoethoxylates (NP1EO), nonylphenol (NP), and octylphenol (OP), in wastewater treated by estuarine and freshwater constructed wetland systems in Dapeng Bay National Scenic Area (DBNSA) and along the Dahan River in Taiwan. Water samples were taken bimonthly at 30 sites in three estuarine constructed wetlands (Datan, Pengcun and Linbian right bank (A and B)) in DBNSA, for eight sampling campaigns. The average removal efficiencies were in the range of 3.13-97.3% for wetlands in DBNSA. The highest average removal occurred in the east inlet to the outlet of the Tatan wetland. The most frequently detected compound was OP (57.7%), whose concentration was up to 1458.7 ng/L in DBNSA. NP was seen in only 20.5% of the samples. The temporal variation of EDs showed a decrease across seasons, where summer>spring>winter>autumn in these constructed wetlands. The removal efficiencies of EDs by estuarine wetlands, in decreasing order, were Datan>Pengcun>Linbian right bank in DBNSA. Water samples collected at 18 sites in three freshwater constructed wetlands (Daniaopi, Hsin-Hai I, and Hsin-Hai II) along the riparian area of Dahan River. NP2EO was the most abundant compound, with a concentration of up to 11,200 ng/L. Removal efficiencies ranged from 55% to 91% for NP1EO, NP2EO, and NP in Hsin-Hai I. The average removal potential of EDs in freshwater constructed wetlands, in decreasing order, was Hsin-Hai II>Daniaopi>Hsin-Hai I constructed wetlands. The lowest concentrations of the selected compounds were observed in the winter. The highest removal efficiency of the selected phenolic endocrine disruptors was achieved by Hsin-Hai I wetland. The calculated risk quotients used to evaluate the ecological risk were up to 30 times higher in the freshwater wetlands along Dahan River than in the estuarine (DBNSA) constructed wetlands, indicating

  20. Distribution of tritium in estuarine waters: the role of organic matter

    International Nuclear Information System (INIS)

    Turner, Andrew; Millward, Geoffrey E.; Stemp, Martin

    2009-01-01

    Tritium is an important environmental radionuclide whose reactivity with ligands and solids in aquatic systems is assumed to be limited. We studied the fractionation and sorption of tritium (added as tritiated water) in river water and seawater, and found that its distribution appears to be influenced by its affinity for organic matter. Tritium rapidly equilibrates with dissolved organic ligands that are retained by a reverse-phase C18 column, and with suspended sediment particles. Significantly, a measurable fraction of sorbed tritium associates with proteinaceous material that is potentially available to sediment-feeding organisms. These characteristics have not been reported previously and cannot be accounted for solely by isotopic exchange with hydrogen. Nevertheless, they are in qualitative agreement with available measurements of tritium in estuarine and coastal waters where its principal discharge is as tritiated water. Further research into the estuarine biogeochemical behaviour of tritium is required and radiological distribution coefficients and concentration factors that are assumed for this radionuclide may require reconsideration.

  1. Distribution of tritium in estuarine waters: the role of organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Andrew [Consolidated Radio-isotope Facility, School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: aturner@plymouth.ac.uk; Millward, Geoffrey E.; Stemp, Martin [Consolidated Radio-isotope Facility, School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2009-10-15

    Tritium is an important environmental radionuclide whose reactivity with ligands and solids in aquatic systems is assumed to be limited. We studied the fractionation and sorption of tritium (added as tritiated water) in river water and seawater, and found that its distribution appears to be influenced by its affinity for organic matter. Tritium rapidly equilibrates with dissolved organic ligands that are retained by a reverse-phase C18 column, and with suspended sediment particles. Significantly, a measurable fraction of sorbed tritium associates with proteinaceous material that is potentially available to sediment-feeding organisms. These characteristics have not been reported previously and cannot be accounted for solely by isotopic exchange with hydrogen. Nevertheless, they are in qualitative agreement with available measurements of tritium in estuarine and coastal waters where its principal discharge is as tritiated water. Further research into the estuarine biogeochemical behaviour of tritium is required and radiological distribution coefficients and concentration factors that are assumed for this radionuclide may require reconsideration.

  2. Geologie et geochimie du fleuve, de l'estuaire et du golfe Saint-Laurent (Canada). [Geology and geochemistry of the river, estuarine, and gulf sections of the St. Lawrence

    Energy Technology Data Exchange (ETDEWEB)

    Couillard, D

    1982-07-01

    This article provides an outline of conditions of particulate material and sediments in the river, estuarine, and gulf sections of the St. Lawrence (Quebec, Canada). The concentration of solids in the river above lac St. Pierre varies between 4 and 10 mg/L, whereas downstream towards Quebec the concentrations rise to 30-50 mg/L. With the exception of the Sorel delta, this section of the river does not constitute a major sink of sedimentary materials, but the surface sediments of the river are enriched with phosphorus, polychlorinated biphenyls, copper, and lead. The portion immediately upstream from Ile d'Orleans is the interface of riverine water and salt water from the Gulf of St. Lawrence and at this point is a region of high concentrations of suspended solids (up to 300 mg/L). The process of sedimentation in the estuary is complicated by the coagulation of fine particles after contact with salt water. As a result, there is a zone of high sedimentation rates of fine particulates enriched in phosphorus, organic matter, and polychlorinated biphenyls in the area of Ile d'Orleans, making constant dredging necessary. Downstream from Ile d'Orleans is a decrease from 40-80 mg/L suspended solids to 1-2 mg/L in the Gulf of St. Lawrence.

  3. Turning the tide: estuarine bars and mutually evasive ebb- and flood-dominated channels

    Science.gov (United States)

    Kleinhans, M. G.; Leuven, J.; van der Vegt, M.; Baar, A. W.; Braat, L.; Bergsma, L.; Weisscher, S.

    2015-12-01

    Estuaries have perpetually changing and interacting channels and shoals formed by ebb and flood currents, but we lack a descriptive taxonomy and forecasting model. We explore the hypotheses that the great variation of bar and shoal morphologies are explained by similar factors as river bars, namely channel aspect ratio, sediment mobility and limits on bar erosion and chute cutoff caused by cohesive sediment. Here we use remote sensing data and a novel tidal flume setup, the Metronome, to create estuaries or short estuarine reaches from idealized initial conditions, with and without mud supply at the fluvial boundary. Bar width-depth ratios in estuaries are similar to those in braided rivers. In unconfined (cohesionless) experimental estuaries, bar- and channel dynamics increase with increasing river discharge. Ebb- and flood-dominated channels are ubiquitous even in entirely straight sections. The apparent stability of ebb- and flood channels is partly explained by the inherent instability of symmetrical channel bifurcations as in rivers.

  4. Detrital shadows: estuarine food web connectivity depends on fluvial influence and consumer feeding mode.

    Science.gov (United States)

    Howe, Emily; Simenstad, Charles A; Ogston, Andrea

    2017-10-01

    We measured the influence of landscape setting on estuarine food web connectivity in five macrotidal Pacific Northwest estuaries across a gradient of freshwater influence. We used stable isotopes (δ 13 C, δ 15 N, δ 34 S) in combination with a Bayesian mixing model to trace primary producer contributions to suspension- and deposit-feeding bivalve consumers (Mytilus trossulus and Macoma nasuta) transplanted into three estuarine vegetation zones: emergent marsh, mudflat, and eelgrass. Eelgrass includes both Japanese eelgrass (Zostera japonica) and native eelgrass (Zostera marina). Fluvial discharge and consumer feeding mode strongly influenced the strength and spatial scale of observed food web linkages, while season played a secondary role. Mussels displayed strong cross-ecosystem connectivity in all estuaries, with decreasing marine influence in the more fluvial estuaries. Mussel diets indicated homogenization of detrital sources within the water column of each estuary. In contrast, the diets of benthic deposit-feeding clams indicated stronger compartmentalization in food web connectivity, especially in the largest river delta where clam diets were trophically disconnected from marsh sources of detritus. This suggests detritus deposition is patchy across space, and less homogenous than the suspended detritus pool. In addition to fluvial setting, other estuary-specific environmental drivers, such as marsh area or particle transport speed, influenced the degree of food web linkages across space and time, often accounting for unexpected patterns in food web connectivity. Transformations of the estuarine landscape that alter river hydrology or availability of detritus sources can thus potentially disrupt natural food web connectivity at the landscape scale, especially for sedentary organisms, which cannot track their food sources through space. © 2017 by the Ecological Society of America.

  5. Estuarine retention of larvae of the crab Rhithropanopeus harrisii

    Science.gov (United States)

    Cronin, Thomas W.

    1982-08-01

    Larvae of estuarine organisms continually face possible export from the parent estuary. Retention of larvae of the estuarine crab Rhithropanopeus harrisii was investigated in the upper Newport River estuary, North Carolina. All of the developmental stages occurred in the same area of the estuary with similar horizontal distributions, and the concentrations of intermediate and late stages were not greatly reduced from those of the first larval stage. This was strong evidence for the continuous retention of larvae in the upper estuary. To determine mechanisms by which retention might be effected, field studies of the vertical distributions and migrations of these larvae were made. The four zoeal stages had similar but complex vertical migration patterns, which varied from study to study. These migrations centered on the depth of no net flow, reducing longitudinal transport during development. Cross-spectral analysis of the larval migrations and the environmental cycles of light, salinity and current speed revealed that each of these external cycles affected larval depth. Megalopae of R. harrisii also migrated vertically, but they were present in much lower concentrations than the zoeal stages, an indication of a change to benthic existence in this final larval form.

  6. Suspended solids moderate the degradation and sorption of waste water-derived pharmaceuticals in estuarine waters.

    Science.gov (United States)

    Aminot, Yann; Fuster, Laura; Pardon, Patrick; Le Menach, Karyn; Budzinski, Hélène

    2018-01-15

    This study focuses on the fate of pharmaceuticals discharged into an estuarine environment, particularly into the Turbidity Maximum Zone (TMZ). Batch experiments were set up to investigate the factors regulating the degradation of 53 selected pharmaceuticals. Treated effluents from Bordeaux city (France) were mixed with water from the estuarine Garonne River during 4weeks under 6 characterized conditions in order to assess the influence of suspended particulates, sterilization, untreated wastewater input and dilution on the degradation kinetics. Of the 53 pharmaceuticals monitored, 43 were quantified at the initial time. Only 7 exhibited a persistent behavior (e.g. carbamazepine, meprobamate) while biotic degradation was shown to be the main attenuation process for 38 molecules (e.g. abacavir, ibuprofen highly degradable). Degradation was significantly enhanced by increasing concentrations of suspended solids. A persistence index based on the half-lives of the compounds has been calculated for each of the 43 pharmaceuticals to provide a practical estimate of their relative stability. The stability of pharmaceuticals in estuarine environments is likely to be highly variable and attenuated primarily by changes in suspended solid concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Redox speciation of particulate iron and manganese during river/ocean mixing

    International Nuclear Information System (INIS)

    Zaw, M.; Szymczak, R.; Payne, T.

    2000-01-01

    Full text: A synchrotron radiation experiment was performed at the Australian National Beamline Facility (Photon Factory, Tsukuba, Japan) to investigate changes in the physico-chemical nature of particles during estuarine mixing. X-ray absorption near edge structure spectra (XANES) analysis was used to determine solid-state redox speciation of iron and manganese throughout the river/ocean salinity transects. Particles (>0.4μm) collected using clean techniques were stored under nitrogen during TROPICS Project expeditions to the Fly and Sepik Rivers, PNG. Results indicated that initially, particulate manganese was mostly present as Mn(IV) and Mn(III) compounds with some surface-adsorbed Mn(II). Similarly, iron was present as particulate Fe(III) and Fe(II/III) compounds with some adsorbed Fe(II). During river-ocean mixing, the proportions of both Mn(II) and Fe(III) significantly increased. These observations maybe due to increasing photochemical activity in the river plume, surface-sorption of reduced species related to the estuarine residence time of particles, or enhanced scavenging of ocean-sourced elements. Copyright (2000) American Chemical Society

  8. Estuarine fish communities respond to climate variability over both river and ocean basins.

    Science.gov (United States)

    Feyrer, Frederick; Cloern, James E; Brown, Larry R; Fish, Maxfield A; Hieb, Kathryn A; Baxter, Randall D

    2015-10-01

    Estuaries are dynamic environments at the land-sea interface that are strongly affected by interannual climate variability. Ocean-atmosphere processes propagate into estuaries from the sea, and atmospheric processes over land propagate into estuaries from watersheds. We examined the effects of these two separate climate-driven processes on pelagic and demersal fish community structure along the salinity gradient in the San Francisco Estuary, California, USA. A 33-year data set (1980-2012) on pelagic and demersal fishes spanning the freshwater to marine regions of the estuary suggested the existence of five estuarine salinity fish guilds: limnetic (salinity = 0-1), oligohaline (salinity = 1-12), mesohaline (salinity = 6-19), polyhaline (salinity = 19-28), and euhaline (salinity = 29-32). Climatic effects propagating from the adjacent Pacific Ocean, indexed by the North Pacific Gyre Oscillation (NPGO), affected demersal and pelagic fish community structure in the euhaline and polyhaline guilds. Climatic effects propagating over land, indexed as freshwater outflow from the watershed (OUT), affected demersal and pelagic fish community structure in the oligohaline, mesohaline, polyhaline, and euhaline guilds. The effects of OUT propagated further down the estuary salinity gradient than the effects of NPGO that propagated up the estuary salinity gradient, exemplifying the role of variable freshwater outflow as an important driver of biotic communities in river-dominated estuaries. These results illustrate how unique sources of climate variability interact to drive biotic communities and, therefore, that climate change is likely to be an important driver in shaping the future trajectory of biotic communities in estuaries and other transitional habitats. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  9. Influence of salinity intrusion on the speciation and partitioning of mercury in the Mekong River Delta

    Science.gov (United States)

    Noh, Seam; Choi, Mijin; Kim, Eunhee; Dan, Nguyen Phuoc; Thanh, Bui Xuan; Ha, Nguyen Thi Van; Sthiannopkao, Suthipong; Han, Seunghee

    2013-04-01

    The lower Mekong and Saigon River Basins are dominated by distinctive monsoon seasons, dry and rainy seasons. Most of the Mekong River is a freshwater region during the rainy season, whereas during the dry season, salt water intrudes approximately 70 km inland. To understand the role of salinity intrusion controlling Hg behavior in the Mekong and Saigon River Basins, Hg and monomethylmercury (MMHg) in surface water and sediment of the Mekong River and in sediment of the Saigon River were investigated in the dry season. Sediment Hg distribution, ranging from 0.12 to 0.76 nmol g-1, was mainly controlled by organic carbon distribution in the Mekong River; however, the location of point sources was more important in the Saigon River (0.21-0.65 nmol g-1). The MMHg concentrations in Mekong (0.16-6.1 pmol g-1) and Saigon (0.70-8.7 pmol g-1) sediment typically showed significant increases in the estuarine head, with sharp increases of acid volatile sulfide. Unfiltered Hg (4.6-222 pM) and filtered Hg (1.2-14 pM) in the Mekong River increased in the estuarine zone due to enhanced particle loads. Conversely, unfiltered MMHg (0.056-0.39 pM) and filtered MMHg (0.020-0.17 pM) was similar between freshwater and estuarine zones, which was associated with mixing dilution of particulate MMHg by organic- and MMHg-depleted resuspended sediment. Partitioning of Hg between water and suspended particle showed tight correlation with the partitioning of organic carbon across study sites, while that of MMHg implied influences of chloride: enhanced chloride in addition to organic matter depletion decreased particulate MMHg in the estuarine zone. Primary production was an important determinant of inter-annual variation of particulate Hg and sediment MMHg. The bloom year showed relatively low particulate Hg with low C/N ratio, indicating biodilution of Hg. In contrast, the percentage of MMHg in sediment increased significantly in the bloom year, likely due to greater availability of

  10. Estuarine Habitats for Juvenile Salmon in the Tidally-Influenced Lower Columbia River and Estuary : Reporting Period September 15, 2008 through May 31, 2009.

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, António M. [Oregon Health & Science University, Science and Technology Center for Coastal Margin Observation and Prediction

    2009-08-02

    This work focuses on the numerical modeling of Columbia River estuarine circulation and associated modeling-supported analyses conducted as an integral part of a multi-disciplinary and multi-institutional effort led by NOAA's Northwest Fisheries Science Center. The overall effort is aimed at: (1) retrospective analyses to reconstruct historic bathymetric features and assess effects of climate and river flow on the extent and distribution of shallow water, wetland and tidal-floodplain habitats; (2) computer simulations using a 3-dimensional numerical model to evaluate the sensitivity of salmon rearing opportunities to various historical modifications affecting the estuary (including channel changes, flow regulation, and diking of tidal wetlands and floodplains); (3) observational studies of present and historic food web sources supporting selected life histories of juvenile salmon as determined by stable isotope, microchemistry, and parasitology techniques; and (4) experimental studies in Grays River in collaboration with Columbia River Estuary Study Taskforce (CREST) and the Columbia Land Trust (CLT) to assess effects of multiple tidal wetland restoration projects on various life histories of juvenile salmon and to compare responses to observed habitat-use patterns in the mainstem estuary. From the above observations, experiments, and additional modeling simulations, the effort will also (5) examine effects of alternative flow-management and habitat-restoration scenarios on habitat opportunity and the estuary's productive capacity for juvenile salmon. The underlying modeling system is part of the SATURN1coastal-margin observatory [1]. SATURN relies on 3D numerical models [2, 3] to systematically simulate and understand baroclinic circulation in the Columbia River estuary-plume-shelf system [4-7] (Fig. 1). Multi-year simulation databases of circulation are produced as an integral part of SATURN, and have multiple applications in understanding estuary

  11. Gamma-spectrometric analysis of river sediments collected around phosphate fertilizer industries

    International Nuclear Information System (INIS)

    Gallardo, M.C.; Garcia-Leon, M.; Mundi, M.; Respaldiza, M.A.

    1993-01-01

    Gamma-ray spectrometric analysis has been carried out on sediments collected in an estuarine system formed by two major rivers in southern Spain. The results show clearly that important amounts of natural radioactivity are accumulating on the bed of both rivers. This radioactivity appears to originate from effluent from several phoshate fertilizer factories adjacent to the estuary. (author)

  12. Characterizing seston in the Penobscot River Estuary.

    Science.gov (United States)

    Meseck, Shannon L; Li, Yaqin; Sunila, Inke; Dixon, Mark; Clark, Paul; Lipsky, Christine; Stevens, Justin R; Music, Paul; Wikfors, Gary H

    2017-10-01

    The Penobscot River Estuary is an important system for diadromous fish in the Northeast United States of American (USA), in part because it is home to the largest remnant population of Atlantic salmon, Salmo salar, in the country. Little is known about the chemical and biological characteristics of seston in the Penobscot River Estuary. This study used estuarine transects to characterize the seston during the spring when river discharge is high and diadromous fish migration peaks in the Penobscot River Estuary. To characterize the seston, samples were taken in spring 2015 for phytoplankton identification, total suspended matter (TSM), percent organic TSM, chlorophyll a, particle size (2 μm-180 μm), particulate carbon and nitrogen concentrations, and stable carbon and nitrogen isotopes. The estuarine profiles indicate that TSM behaved non-conservatively with a net gain in the estuary. As phytoplankton constituted only 1/1000 of the particles, the non-conservative behavior of TSM observed in the estuary was most likely not attributable to phytoplankton. Particulate carbon and nitrogen ratios and stable isotope signals indicate a strong terrestrial, allochthonous signal. The seston in the Penobscot River Estuary was dominated by non-detrital particles. During a short, two-week time period, Heterosigma akashiwo, a phytoplankton species toxic to finfish, also was detected in the estuary. A limited number of fish samples, taken after the 2015 Penobscot River Estuary bloom of H. akashiwo, indicated frequent pathological gill damage. The composition of seston, along with ichthyotoxic algae, suggest the need for further research into possible effects upon resident and migratory fish in the Penobscot River Estuary. Published by Elsevier Ltd.

  13. Geomorphology and soil survey

    Science.gov (United States)

    Laura A. Murray; Bob Eppinette; John H. Thorp

    2000-01-01

    The Coosawhatchie River, through erosion and downcutting, carved a fluvial valley through the Wicomico and Pamlico marine terraces during the late Pleistocene-Holocene period. The floodplain is relatively small and immature compared to the major river systems of the South Carolina Lower Coastal Plain. Consequently, the classic geomorphic features of a larger fluvial...

  14. Factors affecting the bacterial community composition and heterotrophic production of Columbia River estuarine turbidity maxima.

    Science.gov (United States)

    Herfort, Lydie; Crump, Byron C; Fortunato, Caroline S; McCue, Lee Ann; Campbell, Victoria; Simon, Holly M; Baptista, António M; Zuber, Peter

    2017-12-01

    Estuarine turbidity maxima (ETM) function as hotspots of microbial activity and diversity in estuaries, yet, little is known about the temporal and spatial variability in ETM bacterial community composition. To determine which environmental factors affect ETM bacterial populations in the Columbia River estuary, we analyzed ETM bacterial community composition (Sanger sequencing and amplicon pyrosequencing of 16S rRNA gene) and bulk heterotrophic production ( 3 H-leucine incorporation rates). We collected water 20 times to cover five ETM events and obtained 42 samples characterized by different salinities, turbidities, seasons, coastal regimes (upwelling vs. downwelling), locations, and particle size. Spring and summer populations were distinct. All May samples had similar bacterial community composition despite having different salinities (1-24 PSU), but summer non-ETM bacteria separated into marine, freshwater, and brackish assemblages. Summer ETM bacterial communities varied depending on coastal upwelling or downwelling conditions and on the sampling site location with respect to tidal intrusion during the previous neap tide. In contrast to ETM, whole (>0.2 μm) and free-living (0.2-3 μm) assemblages of non-ETM waters were similar to each other, indicating that particle-attached (>3 μm) non-ETM bacteria do not develop a distinct community. Brackish water type (ETM or non-ETM) is thus a major factor affecting particle-attached bacterial communities. Heterotrophic production was higher in particle-attached than free-living fractions in all brackish waters collected throughout the water column during the rise to decline of turbidity through an ETM event (i.e., ETM-impacted waters). However, free-living communities showed higher productivity prior to or after an ETM event (i.e., non-ETM-impacted waters). This study has thus found that Columbia River ETM bacterial communities vary based on seasons, salinity, sampling location, and particle size, with the

  15. Estimation of chlorophyll-a concentration in estuarine waters: case study of the Pearl River estuary, South China Sea

    International Nuclear Information System (INIS)

    Zhang Yuanzhi; Lin Hui; Chen, Chuqun; Chen Liding; Zhang Bing; Gitelson, Anatoly A

    2011-01-01

    The objective of this work is to estimate chlorophyll-a (chl-a) concentration in the Pearl River estuary in China. To test the performance of algorithms for the estimation of the chl-a concentration in these productive turbid waters, the maximum band ratio (MBR) and near-infrared-red (NIR-red) models are used in this study. Specific focus is placed on (a) comparing the ability of the models to estimate chl-a in the range 1-12 mg m -3 , which is typical for coastal and estuarine waters, and (b) assessing the potential of the Moderate Resolution Imaging Spectrometer (MODIS) and Medium Resolution Imaging Spectrometer (MERIS) to estimate chl-a concentrations. Reflectance spectra and water samples were collected at 13 stations with chl-a ranging from 0.83 to 11.8 mg m -3 and total suspended matter from 9.9 to 21.5 g m -3 . A close relationship was found between chl-a concentration and total suspended matter concentration with the determining coefficient (R 2 ) above 0.89. The MBR calculated in the spectral bands of MODIS proved to be a good proxy for chl-a concentration (R 2 > 0.93). On the other hand, both the NIR-red three-band model, with wavebands around 665, 700, and 730 nm, and the NIR-red two-band model (with bands around 665 and 700 nm) explained more than 95% of the chl-a variation, and we were able to estimate chl-a concentrations with a root mean square error below 1 mg m -3 . The two- and three-band NIR-red models with MERIS spectral bands accounted for 93% of the chl-a variation. These findings imply that the extensive database of MODIS and MERIS images could be used to quantitatively monitor chl-a in the Pearl River estuary.

  16. Estimation of chlorophyll-a concentration in estuarine waters: case study of the Pearl River estuary, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yuanzhi; Lin Hui [Institute of Space and Earth Information Science, Yuen Yuen Research Centre for Satellite Remote Sensing, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Chen, Chuqun [South China Institute of Oceanology, Chinese Academy of Sciences, Guangzhou (China); Chen Liding [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing (China); Zhang Bing [Center for Earth Observation and Digital Earth, Chinese Academy of Sciences, Beijing (China); Gitelson, Anatoly A, E-mail: yuanzhizhang@cuhk.edu.hk [Center for Advanced Land Management Information Technologies (CALMIT), School of Natural Resources, University of Nebraska-Lincoln (United States)

    2011-04-15

    The objective of this work is to estimate chlorophyll-a (chl-a) concentration in the Pearl River estuary in China. To test the performance of algorithms for the estimation of the chl-a concentration in these productive turbid waters, the maximum band ratio (MBR) and near-infrared-red (NIR-red) models are used in this study. Specific focus is placed on (a) comparing the ability of the models to estimate chl-a in the range 1-12 mg m{sup -3}, which is typical for coastal and estuarine waters, and (b) assessing the potential of the Moderate Resolution Imaging Spectrometer (MODIS) and Medium Resolution Imaging Spectrometer (MERIS) to estimate chl-a concentrations. Reflectance spectra and water samples were collected at 13 stations with chl-a ranging from 0.83 to 11.8 mg m{sup -3} and total suspended matter from 9.9 to 21.5 g m{sup -3}. A close relationship was found between chl-a concentration and total suspended matter concentration with the determining coefficient (R{sup 2}) above 0.89. The MBR calculated in the spectral bands of MODIS proved to be a good proxy for chl-a concentration (R{sup 2} > 0.93). On the other hand, both the NIR-red three-band model, with wavebands around 665, 700, and 730 nm, and the NIR-red two-band model (with bands around 665 and 700 nm) explained more than 95% of the chl-a variation, and we were able to estimate chl-a concentrations with a root mean square error below 1 mg m{sup -3}. The two- and three-band NIR-red models with MERIS spectral bands accounted for 93% of the chl-a variation. These findings imply that the extensive database of MODIS and MERIS images could be used to quantitatively monitor chl-a in the Pearl River estuary.

  17. Characteristics and landcover of estuarine boundaries: implications for the delineation of the South African estuarine functional zone

    CSIR Research Space (South Africa)

    Veldkornet, DA

    2015-11-01

    Full Text Available Zulu-Natal), cultivation has removed estuarine habitat. Although delineation of boundaries can be complicated by landcover changes, the estuarine lateral boundary in Cape estuaries could be identified based on sediment characteristics (moisture content, organic content...

  18. Estuarine Ecosystem Engineering : Biogeomorphology in the estuarine intertidal

    NARCIS (Netherlands)

    Montserrat Trotsenburg, F.

    2011-01-01

    The aim of this thesis was to investigate how (macro)benthic organisms interact with the ecological functioning, erodibility and small- to medium-scale morphodynamics of estuarine intertidal sediment by modulating its composition and/or properties. In these interactions, scale is of great importance

  19. Contrasts in Sediment Delivery and Dispersal from River Mouth to Accumulation Zones in High Sediment Load Systems: Fly River, Papua New Guinea and Waipaoa River, New Zealand

    Science.gov (United States)

    Ogston, A. S.; Walsh, J. P.; Hale, R. P.

    2011-12-01

    The relationships between sediment-transport processes, short-term sedimentary deposition, subsequent burial, and long-term accumulation are critical to understanding the morphological development of the continental margin. This study focuses on processes involved in formation and evolution of the clinoform in the Gulf of Papua, Papua New Guinea in which much of the riverine sediment accumulates, and comparison to those processes active off the Waipaoa River, New Zealand that form mid-shelf deposits and export sediment to the slope. In tidally dominated deltas, sediment discharged from the river sources must transit through an estuarine region located within the distributary channels, where particle pathways can undergo significant transformations. Within the distributaries of the Fly River tidally dominated delta, near-bed fluid-mud concentrations were observed at the estuarine turbidity maximum and sediment delivery to the nearshore was controlled by the morphology and gradient of the distributary. El Niño results in anonymously low flow and sediment discharge conditions, which limits transport of sediment from the distributaries to the nearshore zone of temporary storage. Because the sediment stored nearshore feeds the prograding clinoform, this perturbation propagates throughout the dispersal system. In wave-dominated regions, transport mechanisms actively move sediment away from the river source, separating the site of deposition and accumulation from the river mouth. River-flood and storm-wave events each create discrete deposits on the Waipaoa River shelf and data has been collected to determine their form, distribution, and relationship to factors such as flood magnitude or wave energy. In this case, transport pathways appear to be influenced by structurally controlled shelf bathymetry. In both cases, the combined fluvial and marine processes can initiate and maintain gravity-driven density flows, and although their triggers and controls differ vastly

  20. Trace elements and radionuclides in the Connecticut River and Amazon River estuary

    International Nuclear Information System (INIS)

    Dion, E.P.

    1983-01-01

    The Connecticut River, its estuary, and the Amazon River estuary were studied to elucidate some of the processes which control river water chemistry and the flux of elements to the sea. The approach taken was to identify inputs to the Connecticut River and to investigate geochemical processes which modify the dissolved load. The form and quantity of nuclides which are in turn supplied to the estuary are altered by processes unique to that transition zone to the ocean. The Connecticut River estuary was sampled on a seasonal basis to investigate the role of the estuary in controlling the flux of elements to the sea. The knowledge gained from the Connecticut River study was applied to the quantitatively more significant Amazon River estuary. There a variety of samples were analyzed to understand the processes controlling the single greatest flux of elements to the Atlantic Ocean. The results indicate that estimates of the total flux of nuclides to the oceans can best be calculated based on groundwater inputs. Unless significant repositories for nuclides exist in the river-estuarine system, the groundwater flux of dissolved nuclides is that which will eventually be delivered to the ocean despite the reactions which were shown to occur in both rivers and estuaries. 153 references, 63 figures, 28 tables

  1. Catchment2Coast: making the link between coastal resource variability and river inputs

    CSIR Research Space (South Africa)

    Monteiro, P

    2003-07-01

    Full Text Available groundwater quantity (flow) and quality (nutrients) on mangrove habitat. The development phase will include a literature review on current understanding of groundwater contribu- tions to tropical estuarine and mangrove ecosystems. The model will use...–estuarine hydrodynamics and physical processes in Maputo Bay A validated hydrodynamic modelling system with two-way nesting of the estu- ary, mangrove, bay and coastal system at Maputo will not only facilitate an investi- gation of the influence of river flow...

  2. Composition of estuarine colloidal material: organic components

    Science.gov (United States)

    Sigleo, A.C.; Hoering, T.C.; Helz, G.R.

    1982-01-01

    Colloidal material in the size range 1.2 nm to 0.4 ??m was isolated by ultrafiltration from Chesapeake Bay and Patuxent River waters (U.S.A.). Temperature controlled, stepwise pyrolysis of the freeze-dried material, followed by gas chromatographic-mass spectrometric analyses of the volatile products indicates that the primary organic components of this polymer are carbohydrates and peptides. The major pyrolysis products at the 450??C step are acetic acid, furaldehydes, furoic acid, furanmethanol, diones and lactones characteristic of carbohydrate thermal decomposition. Pyrroles, pyridines, amides and indole (protein derivatives) become more prevalent and dominate the product yield at the 600??C pyrolysis step. Olefins and saturated hydrocarbons, originating from fatty acids, are present only in minor amounts. These results are consistent with the composition of Chesapeake phytoplankton (approximately 50% protein, 30% carbohydrate, 10% lipid and 10% nucleotides by dry weight). The pyrolysis of a cultured phytoplankton and natural particulate samples produced similar oxygen and nitrogencontaining compounds, although the proportions of some components differ relative to the colloidal fraction. There were no lignin derivatives indicative of terrestrial plant detritus in any of these samples. The data suggest that aquatic microorganisms, rather than terrestrial plants, are the dominant source of colloidal organic material in these river and estuarine surface waters. ?? 1982.

  3. Historical Relationships Between Research and Resource Management in the Apalachicola River Estuary.

    Science.gov (United States)

    Livingston, Robert J

    1991-11-01

    A continuous field research effort has been carried out in the Apalachicola River estuary since March 1972. The information generated from this interdisciplinary study has been directly applied to the management of the Apalachicola resource by means of close associations among local, state, and federal officials and university scientists. During the early years, scientific data were instrumental in the prevention of the impoundment of the Apalachicola River. A series of regional studies was carried out to evaluate various forms of effects due to forestry activities, pesticides, and stormwater runoff from urban areas. A review was made of fisheries problems associated with dredging, overfishing, and marine pollution. Results of such studies were directly applied to local management questions. Research that linked the river wetlands with the estuary, in terms of the input of fresh water, nutrients, and organic matter, served as the basis for the purchase of extensive bottomland tracts. Other initiatives were carried out that were designed to protect the naturally high productivity of the river estuary. Further purchases of estuarine wetlands and barrier island properties were made that formed an almost continuous buffer of publicly held lands between upland developments and critical habitats and important populations of the bay system. A regional management plan was adopted that was designed to limit local municipal development in the estuarine region. Analyses of the long-term scientific data indicated that dominant, commercially important estuarine populations are associated with river flow, local salinity characteristics, and biological (predation, competition) interactions with the salinity regime and food web structure. Such interactions are not straight forward, however; they reflect complex interactions of the freshwater influxes and biological response in the estuary that are not well understood. Species-specific responses to the principal driving factors

  4. Challenging paradigms in estuarine ecology and management

    Science.gov (United States)

    Elliott, M.; Whitfield, A. K.

    2011-10-01

    For many years, estuarine science has been the 'poor relation' in aquatic research - freshwater scientists ignored estuaries as they tended to get confused by salt and tides, and marine scientists were more preoccupied by large open systems. Estuaries were merely regarded by each group as either river mouths or sea inlets respectively. For the past four decades, however, estuaries (and other transitional waters) have been regarded as being ecosystems in their own right. Although often not termed as such, this has led to paradigms being generated to summarise estuarine structure and functioning and which relate to both the natural science and management of these systems. This paper defines, details and affirms these paradigms that can be grouped into those covering firstly the science (definitions, scales, linkages, productivity, tolerances and variability) and secondly the management (pressures, valuation, health and services) of estuaries. The more 'science' orientated paradigms incorporate the development and types of ecotones, the nature of stressed and variable systems (with specific reference to resilience and redundancy), the relationship between generalists and specialists produced by environmental tolerance, the relevance of scale in relation to functioning and connectivity, the sources of production and degree of productivity, the biodiversity-ecosystem functioning and the stress-subsidy debates. The more 'management' targeted paradigms include the development and effects of exogenic unmanaged pressures and endogenic managed pressures, the perception of health and the ability to manage estuaries (related to internal and external influences), and the influence of all of these on the production of ecosystem services and societal benefits.

  5. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Hudson River: REPTILES (Reptile Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for estuarine reptiles (turtles, terrapins) and amphibians (salamanders, frogs) for the Hudson River....

  6. Algal stabilisation of estuarine sediments

    International Nuclear Information System (INIS)

    1992-01-01

    The presence of benthic microalgae can increase the stability of intertidal sediments and influence sediment fluxes within an estuarine environment. Therefore the relative importance of algal stabilisation needs to be understood to help predict the effects of a tidal barrage. The biogenic stabilisation of intertidal estuarine sediments by epipelic diatom films and the macrophyte Vaucheria was studied at three sites on the Severn Estuary. The cohesive strength meter (CSM) was developed to measure surface critical shear stress with varied algal density. A number of techniques have been used to determine the general in situ erodibility of cohesive estuarine sediments. The measurements of sediment shear strength and critical erosion velocity were investigated. Field experiments were undertaken to investigate the effect of algae on binding sediments, and a predictive method for the assessment of sediment stabilisation by algal binding was developed. (author)

  7. Decision Tree Repository and Rule Set Based Mingjiang River Estuarine Wetlands Classifaction

    Science.gov (United States)

    Zhang, W.; Li, X.; Xiao, W.

    2018-05-01

    The increasing urbanization and industrialization have led to wetland losses in estuarine area of Mingjiang River over past three decades. There has been increasing attention given to produce wetland inventories using remote sensing and GIS technology. Due to inconsistency training site and training sample, traditionally pixel-based image classification methods can't achieve a comparable result within different organizations. Meanwhile, object-oriented image classification technique shows grate potential to solve this problem and Landsat moderate resolution remote sensing images are widely used to fulfill this requirement. Firstly, the standardized atmospheric correct, spectrally high fidelity texture feature enhancement was conducted before implementing the object-oriented wetland classification method in eCognition. Secondly, we performed the multi-scale segmentation procedure, taking the scale, hue, shape, compactness and smoothness of the image into account to get the appropriate parameters, using the top and down region merge algorithm from single pixel level, the optimal texture segmentation scale for different types of features is confirmed. Then, the segmented object is used as the classification unit to calculate the spectral information such as Mean value, Maximum value, Minimum value, Brightness value and the Normalized value. The Area, length, Tightness and the Shape rule of the image object Spatial features and texture features such as Mean, Variance and Entropy of image objects are used as classification features of training samples. Based on the reference images and the sampling points of on-the-spot investigation, typical training samples are selected uniformly and randomly for each type of ground objects. The spectral, texture and spatial characteristics of each type of feature in each feature layer corresponding to the range of values are used to create the decision tree repository. Finally, with the help of high resolution reference images, the

  8. Holistic impact assessment and cost savings of rainwater harvesting at the watershed scale

    Science.gov (United States)

    We evaluated the impacts of domestic and agricultural rainwater harvesting (RWH) systems in three watersheds within the Albemarle-Pamlico river basin (southeastern U.S.) using life cycle assessment (LCA) and life cycle cost assessment. Life cycle impact assessment (LCIA) categori...

  9. Holistic Sustainability Assessment of Agricultural Rainwater Harvesting

    Science.gov (United States)

    We present a methodology for holistic sustainability assessment of green infrastructure, applied to agricultural rainwater harvesting (RWH) in the Albemarle-Pamlico river basin. It builds upon prior work in the region through the use of detailed, crop-level management information...

  10. Reductive dehalogenation activity of indigenous microorganism in sediments of the Hackensack River, New Jersey.

    Science.gov (United States)

    Sohn, Seo Yean; Häggblom, Max M

    2016-07-01

    Organohalogen pollutants are of concern in many river and estuarine environments, such as the New York-New Jersey Harbor estuary and its tributaries. The Hackensack River is contaminated with various metals, hydrocarbons and halogenated organics, including polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins. In order to examine the potential for microbial reductive dechlorination by indigenous microorganisms, sediment samples were collected from five different estuarine locations along the Hackensack River. Hexachlorobenzene (HCB), hexabromobenzene (HBB), and pentachloroaniline (PCA) were selected as model organohalogen pollutants to assess anaerobic dehalogenating potential. Dechlorinating activity of HCB and PCA was observed in sediment microcosms for all sampling sites. HCB was dechlorinated via pentachlorobenzene (PeCB) and trichlorobenzene (TriCB) to dichlorobenzene (DCB). PCA was dechlorinated via tetrachloroaniline (TeCA), trichloroanilines (TriCA), and dichloroanilines (DCA) to monochloroaniline (MCA). No HBB debromination was observed over 12 months of incubation. However, with HCB as a co-substrate slow HBB debromination was observed with production of tetrabromobenzene (TeBB) and tribromobenzene (TriBB). Chloroflexi specific 16S rRNA gene PCR-DGGE followed by sequence analysis detected Dehalococcoides species in sediments of the freshwater location, but not in the estuarine site. Analysis targeting 12 putative reductive dehalogenase (rdh) genes showed that these were enriched concomitant with HCB or PCA dechlorination in freshwater sediment microcosms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Comparison of estuarine sediment record with modelled rates of sediment supply from a western European catchment since 1500

    Science.gov (United States)

    Poirier, Clément; Poitevin, Cyril; Chaumillon, Éric

    2016-09-01

    Marine and estuarine sediment records reporting impacts of historical land use changes exist worldwide, but they are rarely supported by direct quantified evidence of changes in denudation rates on the related catchments. Here we implement a spatially-resolved RUSLE soil erosion model on the 10 000 km2 Charente catchment (France), supplied with realistic scenarios of land-cover and climate changes since 1500, and compare the results to a 14C-dated estuarine sediment record. Despite approximations, the model correctly predicts present-day Charente river sediment load. Back-cast modelling suggests that the Charente catchment is an interesting case where the sediment supply did not change despite increase in soil erosion resulting from 18th-century deforestation because it was mitigated by drier climate during the same period. Silt-sand alternations evidenced in the sediment record were correlated with sub-decadal rainfall variability.

  12. Anthropogenic Influences on Estuarine Sedimentation and Ecology: Examples from Varved Sediments of the Pettaquamscutt River Estuary, Rhode Island

    Science.gov (United States)

    Estuaries and lakes are undergoing anthropogenic alterations as development and industry intensify in the modern world. Assessing the ecological health of such water bodies is difficult because accurate accounts of pre-anthropogenic estuarine/lacustrine conditions do not exist. ...

  13. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Hudson River: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species for the Hudson River. Vector polygons in this data set...

  14. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Hudson River: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species in the Hudson River. Vector polygons in this...

  15. Anthropogenic Influences on Estuarine Sedimentation and Ecology: Examples from Varved Sediments of the Pettaquanscutt River Estuary, Rhode Island

    Science.gov (United States)

    Estuaries and lakes are undergoing anthropogenic alterations as development and industry intensify in the modern world. Assessing the ecological health of such water bodies is difficult because accurate accounts of pre-anthropogenic estuarine/lacustrine conditions do not exist. S...

  16. Anthropogenic emissions of 210Po, 210Pb and 226Ra in an estuarine environment

    International Nuclear Information System (INIS)

    Martinez-Aguirre, A.; Garcia-Leon, M.; Gasco, C.; Travesi, A.

    1996-01-01

    An extensive study on the distribution of natural radionuclides in an estuarine ecosystem located in Southwestern Spain is presented. This environment is highly affected by the wastes released by a phosphoric acid industry which uses phosphate rocks raw material for fertilizer production. This rock has generally high concentrations of U and its daughters. The estuary is formed by two rivers. Odiel and Tinto, which have a common mouth into the Atlantic Ocean and a salt marsh (Odiel marsh) affected by the income of Odiel riverwaters. This river receives directly the liquid and part of the solid (gypsum) wastes released from the industries. Besides that, most of the phosphogypsum wastes are stored in uncovered piles at the right margin of the Tinto river. The study has concluded that the wastes from such industries are the cause of the enhanced concentrations found at the bed of both river channels as well as the enhancement found in surface soils in certain zones of the Odiel wet marshland. Indeed, the Northern marsh and the Mojarrera channel at the Odiel marsh seem to be the main sinks of the contaminant released by the phosphoric acid industry. (author). 13 refs., 3 figs., 4 tabs

  17. Anti-cyclonic circulation driven by the estuarine circulation in a gulf type ROFI

    Science.gov (United States)

    Fujiwara, T.; Sanford, L. P.; Nakatsuji, K.; Sugiyama, Y.

    1997-08-01

    Baroclinic residual circulation processes are examined in gulf type Regions Of Freshwater Influence (ROFIs), which have large rivers discharging into a rounded head wider than the Rossby internal deformation radius. Theoretical and observational investigations concentrate on Ise Bay, Japan, with supporting data from Osaka Bay and Tokyo Bay. Simplified analytical solutions are derived to describe the primary features of the circulation. Three dimensional residual current data collected using moored current meters and shipboard acoustic doppler current profilers (ADCPs), satellite imagery and density structure data observed using STDs, are presented for comparison to the theoretical predictions. There are three key points to understanding the resulting circulation in gulf type ROFIs. First, there are likely to be three distinct water masses: the river plume, a brackish upper layer, and a higher salinity lower layer. Second, baroclinic processes in gulf type ROFIs are influenced by the Earth's rotation at first order. Residual currents are quasi-geostrophic and potential vorticity is approximately conserved. Third, the combined effects of a classical longitudinal estuarine circulation and the Earth's rotation are both necessary to produce the resulting circulation. Anti-cyclonic vorticity is generated in the upper layer by the horizontal divergence associated with upward entrainment, which is part of the estuarine circulation. The interaction between anti-cyclonic vorticity and horizontal divergence results in two regions of qualitatively different circulation, with gyre-like circulation near the bay head and uniformly seaward anti-cyclonicly sheared flow further towards the mouth. The stagnation point separating the two regions is closer to (further away from) the bay head for stronger (weaker) horizontal divergence, respectively. The vorticity and spin-up time of this circulation are-(ƒ-ω 1)/2 and h/2w 0, respectively, where ƒ is the Coriolis parameter, ω 1 is

  18. The Caloosahatchee River Estuary: a monitoring partnership between Federal, State, and local governments, 2007-13

    Science.gov (United States)

    Patino, Eduardo

    2014-01-01

    The tidal Caloosahatchee River and downstream estuaries have substantial environmental, recreational, and economic value for southwest Florida residents and visitors. Modifications to the Caloosahatchee River watershed have altered the predevelopment hydrology, thereby threatening the environmental health of estuaries in the area. Hydrologic monitoring of the freshwater contributions from tributaries to the tidal Caloosahatchee River and its estuaries is necessary to adequately describe the total freshwater inflow and constituent loads to the delicate estuarine system.

  19. Anomalous behaviour of uranium isotopes in backwater sediments of Zuari river

    Digital Repository Service at National Institute of Oceanography (India)

    Joshi, L.U; Zingde, M.D.; Abidi, S

    The surface leaching of the labile component of uranium has been carried out in estuarine sediments of Zuari River in Goa, India The measurements of alpha activities of sup(238) U, sup(235) U and sup(234) U in the leachates indicated a remarkable...

  20. A site study of the multiple effects of thermal releases on the aquatic life in an estuarine area

    International Nuclear Information System (INIS)

    Borgese, D.; Dinelli, G.; Guzzi, L.; Smedile, E.

    1975-01-01

    The estuarine area of a river represents a typical site where different factors have to be considered when trying to assess the actual impact on the aquatic life of industrial thermal releases. These factors may be physical (river flow, sea currents, tides, residence time of waters in marshes and lagoons), biological (bio-mass production, mutual organic matter exchange between fresh and sea waters) and economic such as the commercial importance of fishing. In this respect the siting of a large power station in the Po river delta may cause serious problems for the conservation of the existing ecosystem. Thus a multidisciplinary approach with a view to predicting the final thermal impact of a power station on the environment seems fully justified despite its complexity. Therefore a detailed research programme has been established in order to study the following main points: (a) structure of the plant and animal populations; (b) primary production and bacterial activity; (c) physical and chemical characteristics of estuarine waters; (d) coastal characterization; (e) thermal effects on the biocenosis entering the condenser of existing plants operating under similar conditions. Together with conventional experimental techniques, airborne infra-red (IR) and multi-spectra (MS) surveys are planned as, according to preliminary investigations, they provide essential information for the recognition of water flow patterns and aquatic plant growth. The behaviour of the particular ecosystem will be simulated using mathematical models defined on a system theory approach, where the descriptive functions and rate constants come from experimental studies conducted in situ and with laboratory tests. In fact results of preliminary airborne scanning IR and MS surveys combined with biological studies confirm the need for systematic research on the Po river delta. (author)

  1. Pollution history of the Savannah River estuary. Final report, September 1, 1976--December 31, 1977

    International Nuclear Information System (INIS)

    Goldberg, E.D.; Hodge, V.; Griffin, J.J.; Koide, M.; Windom, H.

    1978-04-01

    Records of natural and pollutant fluxes to the Savannah River Estuary are found in some river and marsh deposits into which time frames can be introduced by Pb-210 or plutonium geochronologies. Plutonium releases from the Savannah River Plant are evident in only one deposit and in marsh grass which received the transuranic element from atmospheric transport. The pollution records can be disturbed by bioturbative activities of organisms, by the input of marine solid phases to the estuarine deposits, and by river scour and fill

  2. Detection of cyanotoxins (microcystins/nodularins) in livers from estuarine and coastal bottlenose dolphins (Tursiops truncatus) from Northeast Florida.

    Science.gov (United States)

    Brown, Amber; Foss, Amanda; Miller, Melissa A; Gibson, Quincy

    2018-06-01

    Microcystins/Nodularins (MCs/NODs) are potent hepatotoxic cyanotoxins produced by harmful algal blooms (HABs) that occur frequently in the upper basin of the St. Johns River (SJR), Jacksonville, FL, USA. Areas downstream of bloom locations provide critical habitat for an estuarine population of bottlenose dolphins (Tursiops truncatus). Since 2010, approximately 30 of these dolphins have stranded and died within this impaired watershed; the cause of death was inconclusive for a majority of these individuals. For the current study, environmental exposure to MCs/NODs was investigated as a potential cause of dolphin mortality. Stranded dolphins from 2013 to 2017 were categorized into estuarine (n = 17) and coastal (n = 10) populations. Because estuarine dolphins inhabit areas with frequent or recurring cyanoblooms, they were considered as a comparatively high-risk group for cyanotoxin exposure in relation to coastal animals. All available liver samples from estuarine dolphins were tested regardless of stranding date, and samples from coastal individuals that stranded outside of the known cyanotoxin bloom season were assessed as controls. The MMPB (2-methyl-3-methoxy-4-phenylbutiric acid) technique was used to determine total (bound and free) concentrations of MCs/NODS in liver tissues. Free MCs/NODs extractions were conducted and analyzed using ELISA and LC-MS/MS on MMPB-positive samples to compare test results. MMPB testing resulted in low-level total MCs/NODs detection in some specimens. The Adda ELISA produced high test values that were not supported by concurrent LC-MS/MS analyses, indicative of false positives. Our results indicate that both estuarine and coastal dolphins are exposed to MCs/NODs, with potential toxic and immune health impacts. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Occurrences of dissolved trace metals (Cu, Cd, and Mn) in the Pearl River Estuary (China), a large river-groundwater-estuary system

    Science.gov (United States)

    Wang, Deli; Lin, Wenfang; Yang, Xiqian; Zhai, Weidong; Dai, Minhan; Arthur Chen, Chen-Tung

    2012-12-01

    This study for the first time examined dissolved metals (Cu, Cd, and Mn) together with dissolved oxygen and carbonate system in the whole Pearl River Estuary system, from the upper rivers to the groundwater discharges until the estuarine zone, and explored their potential impacts in the adjacent northern South China Sea (SCS) during May-August 2009. This river-groundwater-estuary system was generally characterized by low dissolved metal levels as a whole, whilst subject to severe perturbations locally. In particular, higher dissolved Cu and Cd occurred in the North River (as high as 60 nmol/L of Cu and 0.99 nmol/L of Cd), as a result of an anthropogenic source from mining activities there. Dissolved Cu levels were elevated in the upper estuary near the city of Guangzhou (Cu: ˜40 nmol/L), which could be attributable to sewage and industrial effluent discharges there. Elevated dissolved metal levels (Cu: ˜20-40 nmol/L; Cd: ˜0.2-0.8 nmol/L) also occurred in the groundwaters and parts of the middle and lower estuaries, which could be attributable to a series of geochemical reactions, e.g., chloride-induced desorption from the suspended sediments, oxidation of metal sulfides, and the partial dissolution of minerals. The high river discharge during our sampling period (May-August 2009) significantly diluted anthropogenic signals in the estuarine mixing zone. Of particular note was the high river discharge (which may reach 18.5 times as high as in the dry season) that transported anthropogenic signals (as indicated by dissolved Cu and Cd) into the adjacent shelf waters of the northern SCS, and might have led to the usually high phytoplankton productivity there (chlorophyll-a value >10 μg/L).

  4. Tidal variations in the Sundarbans estuarine system, India

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterjee, M.; Shankar, D.; Sen, G.K.; Sanyal, P.; Sundar, D.; Michael, G.S.; Chatterjee, A.; Amol, P.; Mukherjee, D.; Suprit, K.; Mukherjee, A.; Vijith, V.; Chatterjee, S.; Basu, A.; Das, M.; Chakraborti, S.; Kalla, A.; Misra, S.K.; Mukhopadhyay, S.; Mandal, G.; Sarkar, K.

    Situated in the eastern coastal state of West Bengal, the Sundarbans Estuarine System (SES) is India’s largest monsoonal, macro-tidal delta-front estuarine system. It comprises the southernmost part of the Indian portion of the Ganga...

  5. 77 FR 60107 - National Estuarine Research Reserve System

    Science.gov (United States)

    2012-10-02

    ... awareness and community involvement in stewardship, incompatible use by visitors, and ecological impacts of... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research Reserve System AGENCY: Estuarine Reserves Division, Office of Ocean and Coastal Resource Management...

  6. Estuarine River Data for the Ten Thousand Islands Area, Florida, Water Year 2005

    Science.gov (United States)

    Byrne, Michael J.; Patino, Eduardo

    2008-01-01

    The U.S. Geological Survey collected stream discharge, stage, salinity, and water-temperature data near the mouths of 11 tributaries flowing into the Ten Thousand Islands area of Florida from October 2004 to June 2005. Maximum positive discharge from Barron River and Faka Union River was 6,000 and 3,200 ft3/s, respectively; no other tributary exceeded 2,600 ft3/s. Salinity variation was greatest at Barron River and Faka Union River, ranging from 2 to 37 ppt, and from 3 to 34 ppt, respectively. Salinity maximums were greatest at Wood River and Little Wood River, each exceeding 40 ppt. All data were collected prior to the commencement of the Picayune Strand Restoration Project, which is designed to establish a more natural flow regime to the tributaries of the Ten Thousand Islands area.

  7. The pollution history of the Savannah River Estuary. Final report 1 Sep 1976--31 Dec 1977

    International Nuclear Information System (INIS)

    Goldberg, E.D.; Griffin, J.J.; Hodge, V.; Koide, M.

    1978-06-01

    Records of natural and pollutant fluxes to the Savannah River Estuary are found in some river and marsh deposits into which time frames can be introduced by 210 Pb or plutonium geochronologies. Plutonium releases from the Savannah River Plant are evident in only one deposit and in marsh grass which received the transuranic element from atmospheric transport. The pollution records can be disturbed by bioturbative activities of organisms, by the input of marine solid phases to the estuarine deposits, and by river scour and fill

  8. Environmental Sensitivity Index (ESI) Atlas: Hudson River, maps and geographic information systems data (NODC Accession 0014791)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) data for the Hudson River from 1942 to 2005. ESI data characterize estuarine environments and...

  9. Environmental Sensitivity Index (ESI) Atlas: Columbia River, maps and geographic information systems data (NODC Accession 0013951)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) data for the Columbia River from 1979 to 2004. ESI data characterize estuarine environments and...

  10. 78 FR 50038 - National Estuarine Research Reserve System

    Science.gov (United States)

    2013-08-16

    ....33(c), the revised plan meets the reserve's requirements for compliance. The Wells Reserve Management... Reserve System AGENCY: Estuarine Reserves Division, Office of Ocean and Coastal Resource Management.... ACTION: Notice of Public Comment Period for the Wells, Maine National Estuarine Research Reserve...

  11. Estuarine Facies Model Revisited: Conceptual Model of Estuarine Sediment Dynamics During Non-Equilibrium Conditions

    Science.gov (United States)

    Elliott, E. A.; Rodriguez, A. B.; McKee, B. A.

    2017-12-01

    Traditional models of estuarine systems show deposition occurs primarily within the central basin. There, accommodation space is high within the deep central valley, which is below regional wave base and where current energy is presumed to reach a relative minimum, promoting direct deposition of cohesive sediment and minimizing erosion. However, these models often reflect long-term (decadal-millennial) timescales, where accumulation rates are in relative equilibrium with the rate of relative sea-level rise, and lack the resolution to capture shorter term changes in sediment deposition and erosion within the central estuary. This work presents a conceptual model for estuarine sedimentation during non-equilibrium conditions, where high-energy inputs to the system reach a relative maximum in the central basin, resulting in temporary deposition and/or remobilization over sub-annual to annual timescales. As an example, we present a case study of Core Sound, NC, a lagoonal estuarine system where the regional base-level has been reached, and sediment deposition, resuspension and bypassing is largely a result of non-equilibrium, high-energy events. Utilizing a 465 cm-long sediment core from a mini-basin located between Core Sound and the continental shelf, a 40-year sub-annual chronology was developed for the system, with sediment accumulation rates (SAR) interpolated to a monthly basis over the 40-year record. This study links erosional processes in the estuary directly with sediment flux to the continental shelf, taking advantage of the highly efficient sediment trapping capability of the mini-basin. The SAR record indicates high variation in the estuarine sediment supply, with peaks in the SAR record at a recurrence interval of 1 year (+/- 0.25). This record has been compared to historical storm influence for the area. Through this multi-decadal record, sediment flushing events occur at a much more frequent interval than previously thought (i.e. annual rather than

  12. Water quality assessment of Gautami-Godavari mangrove estuarine ecosystem of Andhra Pradesh, India during September 2001

    Digital Repository Service at National Institute of Oceanography (India)

    Tripathy, S.C.; Ray, A.K.; Patra, S.; Sarma, V.V.

    for the communities, more importantly they are believed to play a major role in supporting tropical estuarine and coastal food webs (Alongi and Christo?ersen 1992). It is a fact that the mangrove forests represent an impor- tant carbon and nutrient source... township (K1: Jagannathpuram canal) adjoining the Kakinada bay. High BOD with low DO values in Coringa river (M3{M7) mangrove systems may be due to contamination, either by the in?ow of wastes from terrestrial runo? or of anthropogenic in origin, and is a...

  13. Remediating and Monitoring White Phosphorus Contamination at Eagle River Flats (Operable Unit C), Fort Richardson, Alaska

    National Research Council Canada - National Science Library

    Walsh, M. E; Racine, C. H; Collins, C. M; Walsh, M. R; Bailey, R. N

    2001-01-01

    .... Army Engineer District, Alaska, and U.S. Army Alaska, Public Works, describing the results of research, monitoring, and remediation efforts addressing the white phosphorus contamination in Eagle River Flats, an 865-ha estuarine salt marsh...

  14. The CI-Flow Project: A System for Total Water Level Prediction from the Summit to the Sea

    Science.gov (United States)

    2011-11-01

    round and may be applied to all types of coastal storms , including intense cool- season extratropical cyclones (i.e., nor’easters). In addition...associated with waves, tides, storm surge, rivers, and rainfall, including interactions at the tidal/surge interface Within this project, Cl-FLOW addresses...presented for Hurricane Isabel (2003), Hurricane Earl (20I0), and Tropical Storm Nicole (2010) for the Tar -Pamlico and Neuse River basins of North

  15. Conservation Priority Index for Estuarine Fish (COPIEF)

    Science.gov (United States)

    Branco, Paulo; Costa, José Lino; Raposo de Almeida, Pedro

    2008-12-01

    Public awareness regarding environmental issues has increased in recent decades. The increasing number of impact assessment studies, management and conservation plans, as well as ecological monitoring studies, demand new and more efficient techniques. Indices are an important tool to aid biologists in these studies and should allow an easier comprehension of the data by managers, decision-makers and the general public. This study presents the first multi-metrical index able to establish a hierarchical ordination of the conservation priority of the estuarine fish species using 72 species from 16 estuarine systems (W and S coasts of Portugal). The index is composed of 10 metrics, comprising species life traits, distribution and population trends. The information needed to score each metric was gathered from the published literature and the index validation was done by external means. This methodology allowed the definition of those fish species most in need of conservation planning, and those less prone to extinction in Portuguese estuarine systems. The proposed index fills a gap in our knowledge and provides a useful tool to the scientific community and to the decision-makers, being a breakthrough in the field of conservation planning of estuarine fish species.

  16. Paleoclimatic and paleoceanographic studies of estuarine and marine sediments using strontium isotopes

    International Nuclear Information System (INIS)

    Ingram, B.L.

    1992-01-01

    Strontium isotopic ratio ( 87 Sr/ 86 Sr) measurements in fossil carbonates and phosphates are used to evaluate paleoceanographic and paleoclimatic environments in Quaternary, Pliocene-Pleistocene, and mid-Cretaceous estuarine and marine sediments. The use of 87 Sr/ 86 Sr measurements as an estuarine paleosalinity and paleoclimatic indicator is developed and applied to San Francisco Bay. 87 Sr/ 86 Sr measurements of foraminifer and molluscan fossils contained in estuarine sediments of late Pleistocene (ca 115 to 125 ka) and late Holocene (4.5 ka) age show cyclic variations indicating that salinity fluctuated with periods of several hundred years, probably reflecting wet-dry cycles associated with fluctuations in solar irradiance caused by sunspot cycles. The average salinity in San Pablo and Richardson bays was significantly lower (by 6 to 8%) over much of the past 4.5 ka than at present, reflecting a combination of decreased freshwater inflow at present associated with water diversion and wetter climatic conditions prior to 2000 years ago. Salinity data are converted to river discharge using salinity-delta flow relations derived from historical records for San Francisco Bay. The data indicate that annual freshwater inflow was at least twice the modern pre-diversion average between 2.5 and 3.0 Ka; this time period is also identified as one of wetter climatic conditions by lake level and treeline records from the Sierra Nevada. Strontium isotopic measurements of marine carbonate and fish teeth to middle Cretaceous age are used to increase the resolution of the existing seawater Sr isotope versus time curve and to assess models for global oceanic anoxic events. The new data using fish teeth show less scatter and variability than previous data. Negative excursions in the 87 Sr/ 86 Sr ratio of 7-14 parts in 10 -5 during Aptian anoxic events suggest a link between increased submarine volcanism and oceanic anoxia

  17. Radionuclide tracers for the fate of metals in the Savannah estuary: River-ocean exchange processes

    International Nuclear Information System (INIS)

    Olsen, C.R.; Thein, M.; Larsen, I.L.; Byrd, J.T.; Windom, H.L.

    1989-01-01

    Plutonium-238 from the US Department of Energy's Savannah River Plant labels riverborne particles, providing a unique opportunity for examining the fate of metals in estuaries and for tracing river-ocean exchange processes. Results indicate that plutonium and lead-210 are enriched on estuarine particles and that inputs of plutonium from oceanic sources greatly exceed inputs from riverborne or drainage-basin sources as far upstream as the landward limit of seawater penetration. We suggest that these radionuclides (and other chemically reactive metals) are being scavenged from oceanic water by sorption onto particles in turbid estuarine and coastal areas. Since estuaries, bays, mangroves, and intertidal areas serve as effective traps for fine particles and associated trace substances, these results have important implications concerning the disposal of chemically reactive substances in oceanic waters. 13 refs., 1 fig., 1 tab

  18. Silversides (Odontesthes bonariensis) reside within freshwater and estuarine habitats, not marine environments

    Science.gov (United States)

    Avigliano, Esteban; Miller, Nathan; Volpedo, Alejandra Vanina

    2018-05-01

    Otolith core-to-edge Sr:Ca ratio was determined by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to analyze the salinity-habitat migration history of the silverside, Odontesthes bonariensis, within the Uruguay River (freshwater) and Río de la Plata Estuary (estuarine water) (Plata Basin, South America). Regular core-to-edge oscillations in Sr:Ca suggest that the silverside makes annual migrations between freshwater (1 PSU) habitats, with no evidence of marine incursion or non-migratory individuals. Empirical equations that represent the relationship between conductivity/salinity and otolith Sr:Ca ratio were used to identify where in an otolith an individual transitioned between freshwater and brackish habitats. In most specimens, the first migration between habitats likely occurred within the first year of life. Average numbers of changes between stable Sr:Ca signatures (sites with different salinities) determined by Change-Point analysis were similar from Uruguay River (8.9 ± 3.7) and Río de la Plata Estuary (7.5 ± 2.5) for comparable age fish (p < 0.05), suggesting that habitat use is similar in both collection sites.

  19. Holocene estuarine sediments as a source of arsenic in Pleistocene groundwater in suburbs of Hanoi, Vietnam

    Science.gov (United States)

    Kuroda, Keisuke; Hayashi, Takeshi; Funabiki, Ayako; Do, An Thuan; Canh, Vu Duc; Nga, Tran Thi Viet; Takizawa, Satoshi

    2017-06-01

    Groundwater pollution by arsenic is a major health threat in suburban areas of Hanoi, Vietnam. The present study evaluates the effect of the sedimentary environments of the Pleistocene and Holocene deposits, and the recharge systems, on the groundwater arsenic pollution in Hanoi suburbs distant from the Red River. At two study sites (Linh Dam and Tai Mo communes), undisturbed soil cores identified a Pleistocene confined aquifer (PCA) and Holocene unconfined aquifer (HUA) as major aquifers, and Holocene estuarine and deltaic sediments as an aquitard layer between the two aquifers. The Holocene estuarine sediments (approximately 25-40 m depth, 9.6-4.8 cal ka BP) contained notably high concentrations of arsenic and organic matter, both likely to have been accumulated by mangroves during the Holocene sea-level highstand. The pore waters in these particular sediments exhibited elevated levels of arsenic and dissolved organic carbon. Arsenic in groundwater was higher in the PCA (25-94 μg/L) than in the HUA (5.2-42 μg/L), in both the monitoring wells and neighboring household tubewells. Elevated arsenic concentration in the PCA groundwater was likely due to vertical infiltration through the arsenic-rich and organic-matter-rich overlying Holocene estuarine sediments, caused by massive groundwater abstraction from the PCA. Countermeasures to prevent arsenic pollution of the PCA groundwater may include seeking alternative water resources, reducing water consumption, and/or appropriate choice of aquifers for groundwater supply.

  20. Low Frequencies of Interference to EPA Quantitative Polymerase Chain Reaction (qPCR) Methods for Microbial Water Quality Monitoring in U.S. Rivers and Streams and Coastal Waters

    Science.gov (United States)

    In collaboration with U.S States and Tribes, the United States Environmental Protection Agency (EPA) conducts periodic and rotating, statistically based surveys of U.S. rivers and streams (National Rivers and Streams Assessment, NRSA), estuarine and Great Lakes nearshore coastal ...

  1. Rocky intertidal macrobenthic communities across a large-scale estuarine gradient

    Directory of Open Access Journals (Sweden)

    Luis Giménez

    2010-03-01

    Full Text Available We evaluated relationships between (1 salinity and species richness and (2 frontal zones and community structure for the rocky intertidal macrobenthic community of the Uruguayan coast. A large-scale sampling design (extent ~500 km covering 9 rocky shores across 3 intertidal levels was performed between September and November 2002. The linear relationship between salinity and species richness (minimum at the freshwater extreme and the lack of correlation between variation in salinity and richness rejected two previous empirical models, explaining variations in species richness along the salinity gradient. Other factors (e.g. turbidity may explain this discrepancy. The estuarine front defined two communities—freshwater and estuarine-marine—differing in species composition and richness. The freshwater community was characterised by low richness and few individuals confined to crevices or tide pools, and must be structured by physical processes (e.g. desiccation; the estuarine-marine community, with individuals occupying almost all available substrata, must be structured by both physical and biological processes. A marine front, separating estuarine and marine habitats, had a weak effect on community structure although estuarine and marine assemblages differed according to species characterising different functional groups. We conclude that the position of the estuarine frontal zones is important for explaining large-scale patterns of community structure in the study area.

  2. Estuarine development and early Holocene transgression across an aeolianite substrate, Caesarea, central Israel

    Science.gov (United States)

    Goff, John A.; Austin, James A.; Goodman-Tchernov, Beverly N.

    2018-04-01

    Estuaries are important features on the coastal landscape due to their potential for rich, diverse, and abundant resources. The modern coast of the southeast Mediterranean is largely devoid of estuaries except in rare circumstances where ample sands are delivered to the shore, such as east of the Nile Delta. Whether or not today's condition is reflective of that present during lower sea-levels is greatly speculative in part due to a dearth of high-resolution sub-surface mapping in the shallower (sediments in water depths 45-10 mbsl, both within paleo-channels of the Crocodile and Hadera rivers, and more broadly across the shelf. These water depths correspond to early Holocene dates ( 10.5-7.5 ka) which, based on global sea-level curves, was a period of rapid ( 1-1.7 cm/yr) sea-level rise. Now-submerged aeolianite ridges (locally referred to as 'kurkar'), cemented aeolian deposits formed during pre-Last-Glacial-Maximum (LGM) seaward advance (regression) of the coastline, likely provided some offshore barrier for estuarine development. These were insufficient, however, to account for all the estuarine deposition interpreted, leading us to hypothesize that sand-constructed barrier islands were also present as sea-level rose during the Holocene. This supply of sand, clearly greater than what is evident today, could have originated from sea-level rise phase eroding Nile Delta sediments transported northward by littoral currents, or from increased output from local rivers during wetter climatic conditions. We also observe a transition from linear, shore-parallel aeolianite ridge morphology features on land and in shallow water, to nested, arcuate features below 30 mbsl. Whereas the linear ridges are thought to be coastal foredune remnants abandoned by the retreating shoreline, the arcuate forms resemble fossil parabolic (blowout) dunes. Based on the recent initiation of parabolic dunes on Cape Cod following anthropogenic denudation of forests there, we suggest that

  3. Some physico-chemical aspects of pollution in the Karnafully river estuary

    International Nuclear Information System (INIS)

    Islam, M.N.; Zamal, H.; Anwar, M.N.; Saha, S.B.

    2003-01-01

    An investigation was carried out to determine the characteristics of low tide water of Karnafully river estuary during January to December 1997. The study reveals that low tide water of the estuary is highly turbid which inhibits penetration of incident light (K t =16.66) and limits the euphotic zone within a narrow depth of 0.19 m. The estuarine water is oligohaline and neutral in nature and remains under-saturated with dissolved oxygen throughout the year. The load of different nutrients is higher than that of the world average of river water. (author)

  4. The importance of colloids and mires for the transport of uranium isotopes through the Kalix River watershed and Baltic Sea

    International Nuclear Information System (INIS)

    Porcelli, D.; Wasserburg, G.J.; Andersson, P.S.

    1997-01-01

    The importance of colloids and organic deposits for the transport of uranium isotopes from continental source regions and through the estuarine environment was investigated in the mire-rich Kalix River drainage basin in northern Sweden and the Baltic Sea. Ultrafiltration techniques were used to separate uranium and other elements associated with colloids > 10 kD and >3 kD from open-quotes soluteclose quotes uranium and provided consistent results and high recovery rates for uranium as well as for other elements from large volume samples. Uranium concentrations in 0.45 μm-filtered Kalix River water samples increased by a factor of 3 from near the headwaters in the Caledonides to the river mouth while major cation concentrations were relatively constant. 234 U 238 U ratios were high (δ 234 U = 770-1500) throughout the basin, without showing any simple pattern, and required a supply of 234 U-rich water. Throughout the Kalix River, a large fraction (30-90%) of the uranium is carried by >10 kD colloids, which is compatible with uranium complexation with humic acids. No isotopic differences were found between colloid-associated and solute uranium. Within the Baltic Sea, about half of the uranium is removed at low salinities. The proportion that is lost is equivalent to that of river-derived colloid-bound uranium, suggesting that while solute uranium behaves conservatively during estuarine mixing, colloid-bound uranium is lost due to rapid flocculation of colloidal material. The association of uranium with colloids therefore may be an important parameter in determining uranium estuarine behavior. Mire peats in the Kalix River highly concentrate uranium and are potentially a significant source of recoil 234 U to the mirewaters and river waters. However, mirewater data clearly demonstrate that only small 234 U/ 238 U shifts are generated relative to inflowing groundwater. 63 refs., 8 figs., 3 tabs. groundwater. 63 refs., 8 figs., 3 tabs

  5. Satellite Derived Water Quality Observations Are Related to River Discharge and Nitrogen Loads in Pensacola Bay, Florida

    OpenAIRE

    John C. Lehrter; John C. Lehrter; Chengfeng Le

    2017-01-01

    Relationships between satellite-derived water quality variables and river discharges, concentrations and loads of nutrients, organic carbon, and sediments were investigated over a 9-year period (2003–2011) in Pensacola Bay, Florida, USA. These analyses were conducted to better understand which river forcing factors were the primary drivers of estuarine variability in several water quality variables. Remote sensing reflectance time-series data were retrieved from the MEdium Resolution Imaging ...

  6. Mapping Sea Level Rise Behavior in an Estuarine Delta System: A Case Study along the Shanghai Coast

    Directory of Open Access Journals (Sweden)

    H.Q. Cheng

    2018-02-01

    Full Text Available Sea level rise (SLR is a major projected threat of climate change that is expected to affect developing coastal cities located in estuarine delta regions. Shanghai is one such city, being located in the Yangtze River Delta (YRD. It is difficult, however, for decision-makers to implement adaptation due to the uncertain causes, magnitudes, and timings of SLR behaviors. This paper attempts to map the causes and magnitudes of SLR behaviors on a decadal scale. We analyze the tidal level records from 11 tidal gauge stations and the corresponding bathymetry measurements around these stations since 1921. We identify three new SLR behaviors along the Shanghai coast due to anthropogenic geomorphologic changes (AGCs, besides the well-known eustatic sea level rise (ESLR, tectonic subsidence (TS, and urban land subsidence (ULS. The first new behavior is regional sea level rise (RSLR, which occurs as a result of land reclamation and deep waterway regulation. The second is regional sea level fall (RSLF, which occurs because the channel bed is eroded due to sediment supply decline in the river catchment. The last SLR behavior is local tidal datum rise (LTDR. Thus, we project that the magnitude of SLR for the Shanghai coast ranges from 10 cm to 16 cm from 2011 to 2030. Clarifying SLR behaviors is important to aid local decision-makers in planning structural and non-structural measures to combat escalating flood damage costs in an estuarine delta system; this field is full of future challenges. Keywords: Sea level rise behavior, Anthropogenic geomorphologic change, Local tidal datum, Flood management, Adaptation

  7. Association of plutonium with sediments from the Ob and Yenisey Rivers and Estuaries

    International Nuclear Information System (INIS)

    Skipperud, Lindis; Brown, Justin; Fifield, L. Keith; Oughton, Deborah H.; Salbu, Brit

    2009-01-01

    The present study applied sequential extraction techniques to investigate the binding and mobility of plutonium (Pu) in sediments from the rivers and estuaries of the Ob and Yenisey. As a study site, the Ob and Yenisey are particularly interesting as both rivers have weapons-grade Pu sources in their catchment areas, including the Russian Pu production and reprocessing plants at Mayak, Tomsk-7 and Krashnoyarsk, and the Semipalantinsk nuclear weapons testing site in Kazakhstan. Plutonium activity and 240 Pu/ 239 Pu ratios were determined using accelerator mass spectrometry (AMS). Sequential extractions showed that between 47 and 80% of the Pu in Yenisey River sediments and 35-53% of the Pu in soils around the Techa River are mobilized with weak oxidising agents, which can indicate that Pu is bound to organic material. In contrast, Pu in Ob and Yenisey Estuarine sediments was more strongly bound, with 60-100% being found in the HNO 3 -extractable fraction. This change in speciation could reflect either that Pu bound to organic material in the Techa and Yenisey River sediments becomes more fixed to the sediments with time, or that organic-bound Pu is mobilized and released to the water when the sediments encounter the more saline water of the Ob and Yenisey estuaries. In general, 240 Pu/ 239 Pu ratios were relatively consistent between different extraction fractions, although, in whole sediments, an increase in ratio was observed with distance from the source. This reflects the increased influence of weapon fallout from catchment runoff within the river systems, as compared to the weapons-grade sources close to the production and reprocessing plants. Knowledge of Pu speciation in the Ob and Yenisey Rivers, and the processes controlling its behaviour in estuarine systems, can improve predictions of its transfer and subsequent environmental impact to Arctic Seas

  8. Radium isotopes in suspended matter in an estuarine system in the southwest of Spain

    International Nuclear Information System (INIS)

    Perianez, R.; Garcia-Leon, M.; Abril, J.M.

    1994-01-01

    The presence of 226 Ra and 224 Ra in suspended matter from an estuarine system which surrounds a phosphate fertilizer complex has been investigated. The results have confirmed an important radioactive impact from the industrial complex, since up to 2.5 Bq 226 Ra/g suspended matter (dry) has been measured. The influence of tides and seasonal conditions, through changes in salinity, has been found to be relevant. The distribution coefficients for 226 Ra between the suspended matter and the river water have been calculated. The values are in agreement by order of magnitude with those found in the literature, but they clearly depend on tidal state and seasonal conditions. (author) 14 refs.; 6 figs.; 2 tabs

  9. Meta-analysis of estuarine nurseries

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Densities of juvenile fishery species and other animals (all generally 100 mm total length) were summarized for shallow estuarine areas along coastal Texas and...

  10. Dissolved carbon dynamics in the freshwater-saltwater mixing zone of a coastal river entering the Northern Gulf of Mexico

    Science.gov (United States)

    He, S.; Xu, Y. J.

    2017-12-01

    Estuaries play an important role in the dynamics of dissolved carbon from freshwater to marine systems. This study aims to determine how dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) concentrations change along an 88-km long estuarine river with salinity ranging from 0.02 to 29.50. The study is expected to elucidate which processes most likely control carbon dynamics in a freshwater-saltwater mixing system, and to evaluate the net metabolism of this estuary using mixing curves and stable isotope analyses. From November 2014 to February 2016, water samples were collected and in-situ measurements on ambient water conditions were performed during eighteen field trips at six sites from upstream to downstream of the Calcasieu River, which enters the Northern Gulf of Mexico in the southern United States. δ13CDIC and δ13CDOC were measured from May 2015 to February 2017 during five of the field trips. The DIC concentration and δ13CDIC increased rapidly with increasing salinity in the mixing zone. The DIC concentrations appeared to be largely influenced by conservative mixing. The δ13CDIC values were close to those suggested by the conservative mixing model for May 2015, June 2015 and November 2015, but lower than those for July 2015 and February 2016, suggesting that an estuarine river can fluctuate from a balanced to a heterotrophic system (i.e., production/respiration aquatic photosynthesis from carbon produced by terrestrial photosynthesis in a river-ocean continuum. These findings suggest that riverine dissolved carbon undergoes a rapid change in freshwater-saltwater mixing, and that these dynamics should be taken into account in carbon processing and budgeting in the world's estuarine systems.

  11. Marine and Estuarine Pollution.

    Science.gov (United States)

    Reish, Donald J.

    1978-01-01

    Presents a literature review of the effects of various pollutants on marine and estuarine organisms, covering publications of 1976-77. This review includes: (1) effects of pesticides, dredging, dumping, sludge, and petroleum hydrocarbons; and (2) diseases and tissue abnormalities. A list of 441 references is also presented. (HM)

  12. Birds of Mahi River estuary, Gujarat, India

    Directory of Open Access Journals (Sweden)

    P.J. Pandya

    2010-06-01

    Full Text Available The Mahi river estuary is one of the major estuaries of Gujarat. This paper presents a comprehensive list of birds of the Mahi river estuary (nearly 50 km stretch and the adjacent banks/ravines and defines the avian diversity at three major estuarine gradations with a brief check of similarity and diversity within the three. The present observation is the outcome of a 3 year period from August 2006 to July 2009. A sum total of 118 species belonging to 42 families were reported and listed as on Upstream, Midstream, and Downstream of estuary. No significant difference was seen in the species richness at the three zones; a change in avian composition at upstream and downstream was notable.

  13. Trace elements and radionuclides in the Connecticut River and Amazon River estuary

    International Nuclear Information System (INIS)

    Dion, E.P.

    1983-01-01

    The Connecticut River, its estuary and the Amazon River plume were studied to elucidate processes which control the flux of nuclides to the sea. Major ions (Ca, Mg, Na, Cl, Bicarbonate) and selected trace elements (Ra, Ba, Cu, Si) are introduced to the Connecticut River in proportion to the total dissolved load of various groundwaters. Si, Ra, and Ba are subject to removal from solution by seasonal diatom productivity; whereas the other groundwater-derived elements are found in proportion to TDS both time and space. These nuclides are released in the estuary when a portion of the Ra, Ba, and Si in riverine biogenic detritus is trapped in salt marshes and coves bordering the estuary where it redissolves and is exported to the main river channel at ebb tide. In the Amazon River estuary, the Ra and Ba are released in mid-salinity waters. Ra and Ba together with Si are subsequently removed by diatom productivity as reflected in increased Ra and Ba in the suspended particles and depleted dissolved nuclide concentrations in samples from the high productivity zone. In both the Connecticut River system and the Amazon River plume, Cu behaves conservatively; whereas the fates of Fe and Al are linked to soil-derived humic acids. Trace elements in Amazon plume sediments are found simply in proportion to the percentage of fine-grained size materials, despite low Th-228/Ra-228 mean residence times in the plume and the presence of Cs-137 in the sediment column. Estimates of the total flux of nuclides to the oceans can best be calculated on a mass balance basis using groundwater inputs. Unless significant repositories for nuclides exist in the river-estuarine system, the groundwater flux of dissolved nuclides is net flux to the ocean despite the reactions which occur in both rivers and estuaries

  14. Using benthic macroinvertebrate and fish communities as bioindicators of the Tanshui River basin around the greater Taipei area - multivariate analysis of spatial variation related to levels of water pollution.

    Science.gov (United States)

    Young, Shuh-Sen; Yang, Hsi-Nan; Huang, Da-Ji; Liu, Su-Miao; Huang, Yueh-Han; Chiang, Chung-Ting; Liu, Jin-Wei

    2014-07-14

    After decades of strict pollution control and municipal sewage treatment, the water quality of the Tanshui River increased significantly after pollution mitigation as indicated by the River Pollution Index (RPI). The pollution level of the estuarine region decreased from severe pollution to mostly moderately impaired. The most polluted waters are presently restricted to a flow track length between 15-35 km relative to the river mouth. From July 2011 to September 2012, four surveys of fish and benthic macroinvertebrates were conducted at 45 sampling sites around the Tanshui River basin. The pollution level of all the study area indicated by the RPI could also be explained by the Family Biotic Index (FBI) and Biotic Index (BI) from the benthic macroinvertebrate community, and the Index of Biotic Integrity (IBI) of the fish community. The result of canonical correlation analysis between aquatic environmental factors and community structure indicated that the community structure was closely related to the level of water pollution. Fish species richness in the estuarine area has increased significantly in recent years. Some catadromous fish and crustaceans could cross the moderate polluted water into the upstream freshwater, and have re-colonized their populations. The benthic macroinvertebrate community relying on the benthic substrate of the estuarine region is still very poor, and the water layer was still moderately polluted.

  15. Analytical characterization of selective benthic flux components in estuarine and coastal waters

    Science.gov (United States)

    King, Jeffrey N.

    2011-01-01

    Benthic flux is the rate of flow across the bed of a water body, per unit area of bed. It is forced by component mechanisms, which interact. For example, pressure gradients across the bed, forced by tide, surface gravity waves, density gradients, bed–current interaction, turbulence, and terrestrial hydraulic gradients, drive an advective benthic flux of water and constituents between estuarine and coastal waters, and surficial aquifers. Other mechanisms also force benthic flux, such as chemical gradients, bioturbation, and dispersion. A suite of component mechanisms force a total benthic flux at any given location, where each member of the suite contributes a component benthic flux. Currently, the types and characteristics of component interactions are not fully understood. For example, components may interact linearly or nonlinearly, and the interaction may be constructive or destructive. Benthic flux is a surface water–groundwater interaction process. Its discharge component to a marine water body is referred to, in some literature, as submarine groundwater discharge. Benthic flux is important in characterizing water and constituent budgets of estuarine and coastal systems. Analytical models to characterize selective benthic flux components are reviewed. Specifically, these mechanisms are for the component associated with the groundwater tidal prism, and forced by surface gravity wave setup, surface gravity waves on a plane bed, and the terrestrial hydraulic gradient. Analytical models are applied to the Indian River Lagoon, Florida; Great South Bay, New York; and the South Atlantic Bight in South Carolina and portions of North Carolina.

  16. 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.

  17. Linkages between the spatial toxicity of sediments and sediment dynamics in the Yangtze River Estuary and neighboring East China Sea.

    Science.gov (United States)

    Gao, Jinjuan; Shi, Huahong; Dai, Zhijun; Mei, Xuefei; Zong, Haibo; Yang, Hongwei; Hu, Lingling; Li, Shushi

    2018-02-01

    Anthropogenic activities are driving an increase in sediment contamination in coastal areas. This poses significant challenges for the management of estuarine ecosystems and their adjacent seas worldwide. However, few studies have been conducted on how dynamic mechanisms affect the sediment toxicity in the estuarine environment. This study was designed to investigate the linkages between sediment toxicity and hydrodynamics in the Yangtze River Estuary (YRE) area. High sediment toxicity was found in the Yangtze River mouth (Region I), the depocenter of the Yangtze River Delta (Region II), and the southeastern area of the adjacent sea (Region III), while low sediment toxicity was found in the northeastern offshore region (Region IV). A spatial comparison analysis and regression model indicated that the distributed pattern of sediment toxicity was likely related to hydrodynamics and circumfluence in the East China Sea (ECS) shelf. Specifically, high sediment toxicity in Region I may be affected by the Yangtze River Pump (YRP) and the low hydrodynamics there, and high toxicity in Region II can be influenced by the low sediment dynamics and fine sediment in the depocenter. The high sediment toxicity in Region III might be related to the combination of the YRP and Taiwan Warm Current, while the low toxicity in Region IV may be influenced by the local coarse-grained relict sand with strong sediment dynamics there. The present research results further suggest that it is necessary to link hydrodynamics and the spatial behavior of sediment and sediment-derived pollutants when assessing the pollution status of estuarine environments, especially for those mega-estuaries and their neighboring ocean environments with complex waves, tides and ocean currents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Stable isotopes and mercury in a model estuarine fish: Multibasin comparisons with water quality, community structure, and available prey base

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Douglas H., E-mail: Doug.Adams@MyFWC.com; Paperno, Richard

    2012-01-01

    Stable-isotope ratios ({delta}{sup 13}C and {delta}{sup 15}N) and mercury in a model predator, and associated prey community assessments were used to make inferences regarding food web relationships and how these relationships are influenced by habitat variability and anthropogenic factors. Although interconnected, the three major basins of the Indian River Lagoon system on the Atlantic coast of Florida comprise noticeably different available habitat types with spatially distinct faunal communities and available prey for spotted seatrout, Cynoscion nebulosus, a model predatory fish species. Water quality, degree of urbanization, human population density, and levels of nitrogen enrichment clearly differ between these representative estuarine basins. The differences can influence feeding ecology and therefore result in different mercury concentrations and different stable-isotope signatures of spotted seatrout between basins. Mercury concentrations in spotted seatrout were greatest in Mosquito Lagoon (ML) and least in the Indian River Lagoon proper (IRL), although concentrations were low for all basins. Spotted seatrout from IRL were carbon-depleted and nitrogen-enriched compared with those from the other basins; this suggests either that the fish's primary source of carbon in IRL is an algae- or phytoplankton-based food web or that the pathway through the food web is shorter there. The {delta}{sup 15}N values of IRL spotted seatrout were greater than those in the Banana River Lagoon or ML, suggesting slightly different trophic positioning of fish in these basins. The greater {delta}{sup 15}N values in IRL spotted seatrout may also reflect the greater human population density and resultant anthropogenic inputs (e.g., observed higher total nitrogen levels) in IRL compared with the other more pristine basins examined. Understanding species' responses to broad-scale habitat heterogeneity in estuaries and knowing basin-specific differences in stable isotopes

  19. Evaluation of the Level of Organochlorinated Pesticides Contamination in Environment of the Red River and its Balat Estuary

    International Nuclear Information System (INIS)

    Nguyen Manh Am; Dang Duc Nhan; Vo Van Thuan; Nguyen Duc Cu; Luu Van Dieu; Nguyen Chu Hoi

    1995-01-01

    The pollution level of OC pesticides such as Lindane, DDT and its metabolites contaminants in water, sediments and Biota collected along the Red River and from the Balat estuary have, for the first time in the North of Vietnam, been determined by GC technique using capillary columns and electron capture detection (ECD). The concentration of DDT and DDE was found to be up to 38.4 ppb and 27.3 ppb, respectively, in sediments from the Red River and its Balat estuary. Lindane residue in Red River's and Balat estuary's sediments was found at level of 1.3-4.2 and 14.6-52.6 ppb, respectively. In water Lindane contaminant was detected in the sample collected from the estuarine area only, while DDE was found in both River and estuarine water. Residue of Lindane in mussel flesh was found to be always higher (up to 145 ppb) than that of any DDT's metabolites, e.g. the highest value of DDE contaminant is 66 ppb. The finding shows that Lindane contamination in marine environmental samples from the Balat estuary is higher as compared with those from the Mediterranean Sea but DDT's ones are at the same level. (author). 8 refs., 6 tabs., 1 map

  20. Identifying sources of acidity and spatial distribution of acid sulfate soils in the Anglesea River catchment, southern Australia

    Science.gov (United States)

    Wong, Vanessa; Yau, Chin; Kennedy, David

    2015-04-01

    Globally, coastal and estuarine floodplains are frequently underlain by sulfidic sediments. When exposed to oxygen, sulfidic sediments oxidise to form acid sulfate soils, adversely impacting on floodplain health and adjacent aquatic ecoystems. In eastern Australia, our understanding of the formation of these coastal and estuarine floodplains, and hence, spatial distribution of acid sulfate soils, is relatively well established. These soils have largely formed as a result of sedimentation of coastal river valleys approximately 6000 years BP when sea levels were one to two metres higher. However, our understanding of the evolution of estuarine systems and acid sulfate soil formation, and hence, distribution, in southern Australia remains limited. The Anglesea River, in southern Australia, is subjected to frequent episodes of poor water quality and low pH resulting in closure of the river and, in extreme cases, large fish kill events. This region is heavily reliant on tourism and host to a number of iconic features, including the Great Ocean Road and Twelve Apostles. Poor water quality has been linked to acid leakage from mining activities and Tertiary-aged coal seams, peat swamps and acid sulfate soils in the region. However, our understanding of the sources of acidity and distribution of acid sulfate soils in this region remains poor. In this study, four sites on the Anglesea River floodplain were sampled, representative of the main vegetation communities. Peat swamps and intertidal marshes were both significant sources of acidity on the floodplain in the lower catchment. However, acid neutralising capacity provided by carbonate sands suggests that there are additional sources of acidity higher in the catchment. This pilot study has highlighted the complexity in the links between the floodplain, upper catchment and waterways with further research required to understand these links for targeted acid management strategies.

  1. Using Benthic Macroinvertebrate and Fish Communities as Bioindicators of the Tanshui River Basin Around the Greater Taipei Area — Multivariate Analysis of Spatial Variation Related to Levels of Water Pollution

    Directory of Open Access Journals (Sweden)

    Shuh-Sen Young

    2014-07-01

    Full Text Available After decades of strict pollution control and municipal sewage treatment, the water quality of the Tanshui River increased significantly after pollution mitigation as indicated by the River Pollution Index (RPI. The pollution level of the estuarine region decreased from severe pollution to mostly moderately impaired. The most polluted waters are presently restricted to a flow track length between 15–35 km relative to the river mouth. From July 2011 to September 2012, four surveys of fish and benthic macroinvertebrates were conducted at 45 sampling sites around the Tanshui River basin. The pollution level of all the study area indicated by the RPI could also be explained by the Family Biotic Index (FBI and Biotic Index (BI from the benthic macroinvertebrate community, and the Index of Biotic Integrity (IBI of the fish community. The result of canonical correlation analysis between aquatic environmental factors and community structure indicated that the community structure was closely related to the level of water pollution. Fish species richness in the estuarine area has increased significantly in recent years. Some catadromous fish and crustaceans could cross the moderate polluted water into the upstream freshwater, and have re-colonized their populations. The benthic macroinvertebrate community relying on the benthic substrate of the estuarine region is still very poor, and the water layer was still moderately polluted.

  2. Using Benthic Macroinvertebrate and Fish Communities as Bioindicators of the Tanshui River Basin Around the Greater Taipei Area — Multivariate Analysis of Spatial Variation Related to Levels of Water Pollution

    Science.gov (United States)

    Young, Shuh-Sen; Yang, Hsi-Nan; Huang, Da-Ji; Liu, Su-Miao; Huang, Yueh-Han; Chiang, Chung-Ting; Liu, Jin-Wei

    2014-01-01

    After decades of strict pollution control and municipal sewage treatment, the water quality of the Tanshui River increased significantly after pollution mitigation as indicated by the River Pollution Index (RPI). The pollution level of the estuarine region decreased from severe pollution to mostly moderately impaired. The most polluted waters are presently restricted to a flow track length between 15–35 km relative to the river mouth. From July 2011 to September 2012, four surveys of fish and benthic macroinvertebrates were conducted at 45 sampling sites around the Tanshui River basin. The pollution level of all the study area indicated by the RPI could also be explained by the Family Biotic Index (FBI) and Biotic Index (BI) from the benthic macroinvertebrate community, and the Index of Biotic Integrity (IBI) of the fish community. The result of canonical correlation analysis between aquatic environmental factors and community structure indicated that the community structure was closely related to the level of water pollution. Fish species richness in the estuarine area has increased significantly in recent years. Some catadromous fish and crustaceans could cross the moderate polluted water into the upstream freshwater, and have re-colonized their populations. The benthic macroinvertebrate community relying on the benthic substrate of the estuarine region is still very poor, and the water layer was still moderately polluted. PMID:25026081

  3. 15 CFR 921.52 - Promotion and coordination of estuarine research.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Promotion and coordination of estuarine research. 921.52 Section 921.52 Commerce and Foreign Trade Regulations Relating to Commerce and... Research Projects § 921.52 Promotion and coordination of estuarine research. (a) NOAA will promote and...

  4. Fundamentals of estuarine physical oceanography

    CERN Document Server

    Bruner de Miranda, Luiz; Kjerfve, Björn; Castro Filho, Belmiro Mendes de

    2017-01-01

    This book provides an introduction to the complex system functions, variability and human interference in ecosystem between the continent and the ocean. It focuses on circulation, transport and mixing of estuarine and coastal water masses, which is ultimately related to an understanding of the hydrographic and hydrodynamic characteristics (salinity, temperature, density and circulation), mixing processes (advection and diffusion), transport timescales such as the residence time and the exposure time. In the area of physical oceanography, experiments using these water bodies as a natural laboratory and interpreting their circulation and mixing processes using theoretical and semi-theoretical knowledge are of fundamental importance. Small-scale physical models may also be used together with analytical and numerical models. The book highlights the fact that research and theory are interactive, and the results provide the fundamentals for the development of the estuarine research.

  5. Tidally-driven Surface Flow in a Georgia Estuarine Saltmarsh

    Science.gov (United States)

    Young, D.; Bruder, B. L.; Haas, K. A.; Webster, D. R.

    2016-02-01

    Estuarine saltmarshes are diverse, valuable, and productive ecosystems. Vegetation dampens wave and current energy, thereby allowing the estuaries to serve as a nursery habitat for shellfish and fish species. Tidally-driven flow transports nutrients into and out of the estuary, nourishing inshore and offshore vegetation and animals. The effects of vegetation on the marsh hydrodynamics and on the estuary creek and channel flow are, unfortunately, poorly understood, and the knowledge that does exist primarily originates from modeling studies. Field studies addressing marsh surface flows are limited due to the difficulty of accurately measuring the water surface elevation and acquiring concurrent velocity measurements in the dense marsh vegetation. This study partially bridges the gap between the model observations of marsh flow driven by water surface elevation gradients and flume studies of flow through vegetation. Three current meters and three pressure transducers were deployed for three days along a transect perpendicular to the main channel (Little Ogeechee River) in a saltmarsh adjacent to Rose Dhu Island (Savannah, Georgia, USA). The pressure transducer locations were surveyed daily with static GPS yielding highly accurate water surface elevation data. During flood and ebb tide, water surface elevation differences between the marsh and Little Ogeechee River were observed up to 15 cm and pressure gradients were observed up to 0.0017 m of water surface elevation drop per m of linear distance. The resulting channel-to-saltmarsh pressure gradients substantially affected tidal currents at all current meters. At one current meter, the velocity was nearly perpendicular to the Little Ogeechee River bank. The velocity at this location was effectively modeled as a balance between the pressure gradient and marsh vegetation-induced drag force using the Darcy-Weisbach/Lindner's equations developed for flow-through-vegetation analysis in open channel flow.

  6. Hurricane Matthew's Effects on Wetland Sources of Organic Matter to North Carolina Coastal Waters.

    Science.gov (United States)

    Rudolph, J. C.; Osburn, C. L.; Paerl, H. W.; Hounshell, A.

    2017-12-01

    Increased frequency and intensity of storm events such as tropical cyclones will have a major impact on estuarine and coastal biogeochemical cycling. Here, we determined the sources of dissolved and particulate organic matter (DOM and POM) as part of a larger study to quantify the short-term (several months) response of carbon and nitrogen cycling in the Neuse River Estuary-Pamlico Sound (NRE-PS) ecosystem to floodwaters associated with Hurricane Matthew. Sampling was conducted weekly in both the NRE-PS (October 2016 to January 2017), the Neuse River (NR) (October to December 2016) and in freshwater wetlands of the Neuse River above head of tide in March 2017. Specific ultraviolet (UV) absorbance at 254 nm (SUVA254) and stable carbon isotope ratios (δ13C-DOC) were used to determine the sources of DOM and POM transported to the NRE-PS in post-hurricane floodwaters. For DOM, SUVA254 values increased from 3.23 ±0.52 mg C L-1 m-1 in the NR to 4.14±0.52 mg C L-1 m-1 in the NRE and then declined to 3.63±0.32 mg C L-1 m-1 in PS. Combined with depleted δ13C-DOC values (-26 to -32‰) and elevated C:N values in the estuary and sound, these results confirm continued loading of fresh terrestrial organic matter into NRE-PS weeks after the storm. For POM, δ13C-POC and C:N ratio results likewise indicated a terrestrial source in floodwaters. SUVA254 values >3.5 mg C L-1 m-1 coupled with the depleted δ13C values and large C:N values were consistent with DOM primarily sourced from wetlands (e.g., wetland SUVA254 = 3.77±0.52 mg C L-1 m-1 in March 2017). We hypothesize that floodwaters connected riverine wetlands to the main channel of the NR, exporting DOM and POM into the NRE-PS. Our results indicate that upstream wetlands play a central and potentially significant role in organic matter enrichment and metabolism of estuarine and coastal waters, in light of increasing frequencies and intensities of tropical cyclones impacting coastal watersheds.

  7. Estuarine abandoned channel sedimentation rates record peak fluvial discharge magnitudes

    Science.gov (United States)

    Gray, A. B.; Pasternack, G. B.; Watson, E. B.

    2018-04-01

    Fluvial sediment deposits can provide useful records of integrated watershed expressions including flood event magnitudes. However, floodplain and estuarine sediment deposits evolve through the interaction of watershed/marine sediment supply and transport characteristics with the local depositional environment. Thus extraction of watershed scale signals depends upon accounting for local scale effects on sediment deposition rates and character. This study presents an examination of the balance of fluvial sediment dynamics and local scale hydro-geomorphic controls on alluviation of an abandoned channel in the Salinas River Lagoon, CA. A set of three sediment cores contained discrete flood deposits that corresponded to the largest flood events over the period of accretion from 1969 to 2007. Sedimentation rates scaled with peak flood discharge and event scale sediment flux, but were not influenced by longer scale hydro-meteorological activities such as annual precipitation and water yield. Furthermore, the particle size distributions of flood deposits showed no relationship to event magnitudes. Both the responsiveness of sedimentation and unresponsiveness of particle size distributions to hydro-sedimentological event magnitudes appear to be controlled by aspects of local geomorphology that influence the connectivity of the abandoned channel to the Salinas River mainstem. Well-developed upstream plug bar formation precluded the entrainment of coarser bedload into the abandoned channel, while Salinas River mouth conditions (open/closed) in conjunction with tidal and storm surge conditions may play a role in influencing the delivery of coarser suspended load fractions. Channel adjacent sediment deposition can be valuable records of hydro-meteorological and sedimentological regimes, but local depositional settings may dominate the character of short term (interdecadal) signatures.

  8. Functional redundancy and sensitivity of fish assemblages in European rivers, lakes and estuarine ecosystems.

    Science.gov (United States)

    Teichert, Nils; Lepage, Mario; Sagouis, Alban; Borja, Angel; Chust, Guillem; Ferreira, Maria Teresa; Pasquaud, Stéphanie; Schinegger, Rafaela; Segurado, Pedro; Argillier, Christine

    2017-12-14

    The impact of species loss on ecosystems functioning depends on the amount of trait similarity between species, i.e. functional redundancy, but it is also influenced by the order in which species are lost. Here we investigated redundancy and sensitivity patterns across fish assemblages in lakes, rivers and estuaries. Several scenarios of species extinction were simulated to determine whether the loss of vulnerable species (with high propensity of extinction when facing threats) causes a greater functional alteration than random extinction. Our results indicate that the functional redundancy tended to increase with species richness in lakes and rivers, but not in estuaries. We demonstrated that i) in the three systems, some combinations of functional traits are supported by non-redundant species, ii) rare species in rivers and estuaries support singular functions not shared by dominant species, iii) the loss of vulnerable species can induce greater functional alteration in rivers than in lakes and estuaries. Overall, the functional structure of fish assemblages in rivers is weakly buffered against species extinction because vulnerable species support singular functions. More specifically, a hotspot of functional sensitivity was highlighted in the Iberian Peninsula, which emphasizes the usefulness of quantitative criteria to determine conservation priorities.

  9. Chapter Three - From Natural to Degraded Rivers and Back Again: A Test of Restoration Ecology Theory and Practice

    NARCIS (Netherlands)

    Feld, C.K.; Birk, S.; Bradley, D.C.; Hering, D.; Kail, J.; Marzin, A.; Melcher, A.; Nemitz, D.; Pedersen, M.L.; Pletterbauer, F.; Pont, D.; Verdonschot, P.F.M.; Friberg, N.

    2011-01-01

    Extensive degradation of ecosystems, combined with the increasing demands placed on the goods and services they provide, is a major driver of biodiversity loss on a global scale. In particular, the severe degradation of large rivers, their catchments, floodplains and lower estuarine reaches has been

  10. Effect of thermal shock on developmental stages of estuarine fish. Final report

    International Nuclear Information System (INIS)

    Dean, J.M.

    1978-12-01

    Physiological data and ecological data show that the few estuarine spawners have a higher thermal tolerance in the embryonic and larval stages than do the freshwater, coastal, or oceanic spawning species. However, since all three groups (freshwater, estuarine, and oceanic spawners) occupy the estuary and coastal waters at different times of the year, knowledge of their physiology and ecology at different developmental or life cycle stages is critical for estuarine management decisions

  11. Surficial and vertical distribution of heavy metals in different estuary wetlands in the Pearl river, South China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Honggang; Cui, Baoshan [State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing (China); Zhang, Kejiang [Xinjiang Research Center of Water and Wastewater Treatment, Xinjiang Deland Co., LTD., Urumqi (China)

    2012-10-15

    A total of 87 soil profiles sampled from five types of wetlands in the Pearl River estuary were analyzed to investigate the surficial and vertical distributions of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn). The results show that wetlands directly connected with rivers (e.g., riparian wetlands, estuarine wetlands, and mangrove wetlands) has much higher metal concentrations than those indirectly connected with rivers (e.g., pond wetlands and reclaimed wetlands). The river water is the major pollution source for all investigated heavy metals. The vertical distribution of heavy metals can be classified into three patterns: (i) linear distribution pattern. The concentration of heavy metals gradually decreases with an increase in soil depth (for riparian and estuarine wetlands); (ii) irregular and stable pattern (for pond and reclaimed wetlands); and (iii) middle enrichment pattern (for mangrove wetlands). In addition to river-borne inputs, a variety of vegetation composition, hydraulic conditions, and human activities also contribute to the variation in distribution of heavy metals in different wetlands. Soil properties (e.g., particle size, pH, salinity, and SOM) also affect the distribution of trace metals in each soil layer. The major pollution source of heavy metals is industrial wastewater. Other sources include agriculture and domestic premises, and atmospheric deposition. This study provides a sound basis for the risk assessment of heavy metals in the studied wetlands and for wetland conservation in general. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Zooplankton From a Reef System Under the Influence of the Amazon River Plume

    Directory of Open Access Journals (Sweden)

    Sigrid Neumann-Leitão

    2018-03-01

    Full Text Available At the mouth of the Amazon River, a widespread carbonate ecosystem exists below the river plume, generating a hard-bottom reef (∼9500 km2 that includes mainly large sponges but also rhodolith beds. The mesozooplankton associated with the pelagic realm over the reef formation was characterized, considering the estuarine plume and oceanic influence. Vertical hauls were carried out using a standard plankton net with 200 μm mesh size during September 2014. An indicator index was applied to express species importance as ecological indicators in community. Information on functional traits was gathered for the most abundant copepod species. Overall, 179 zooplankton taxa were recorded. Copepods were the richest (92 species, most diverse and most abundant group, whereas meroplankton were rare and less abundant. Species diversity (>3.0 bits.ind-1 and evenness (>0.6 were high, indicating a complex community. Small holoplanktonic species dominated the zooplankton, and the total density varied from 107.98 ind. m-3 over the reef area to 2,609.24 ind. m-3 in the estuarine plume, with a significant difference between coastal and oceanic areas. The most abundant copepods were the coastal species ithona plumifera and Clausocalanus furcatus and early stages copepodites of Paracalanidae. The holoplanktonic Oikopleura, an important producer of mucous houses, was very abundant on the reefs. The indicator species index revealed three groups: (1 indicative of coastal waters under the influence of the estuarine plume [Euterpina acutifrons, Parvocalanus crassirostris, Oikopleura (Vexillaria dioica and Hydromedusae]; (2 characterized coastal and oceanic conditions (Clausocalanus; (3 characterized the reef system (O. plumifera. Two major copepods functional groups were identified and sorted according to their trophic strategy and coastal-oceanic distribution. The species that dominated the coastal area and the area over the rhodolith beds are indicators of the estuarine

  13. Reversing tidal flow and estuarine morphodynamics in the Metronome laboratory flume

    NARCIS (Netherlands)

    Kleinhans, M.G.; Leuven, J.R.F.W.; Braat, L.; van der Vegt, M.; van Maarseveen, M.C.G.; Markies, H.; Roosendaal, C.; van Eijk, A.M.

    2016-01-01

    Our objective is to test a novel experimental principle for creating reversing tidal flows of sufficient strength to cause estuarine morphodynamics. The study of estuarine morphodynamics has hitherto been limited to field observation and numerical modelling, whilst fluvial morphodynamics have

  14. Distribution of branched GDGTs in surface sediments from the Colville River, Alaska: Implications for the MBT'/CBT paleothermometer in Arctic marine sediments

    Science.gov (United States)

    Hanna, Andrea J. M.; Shanahan, Timothy M.; Allison, Mead A.

    2016-07-01

    Significant climate fluctuations in the Arctic over the recent past, and additional predicted future temperature changes, highlight the need for high-resolution Arctic paleoclimate records. Arctic coastal environments supplied with terrigenous sediment from Arctic rivers have the potential to provide annual to subdecadal resolution records of climate variability over the last few millennia. A potential tool for paleotemperature reconstructions in these marine sediments is the revised methylation index of branched tetraethers (MBT')/cyclization ratio of branched tetraethers (CBT) proxy based on branched glycerol dialkyl glycerol tetraethers (brGDGTs). In this study, we examine the source of brGDGTs in the Colville River, Alaska, and the adjacent Simpson Lagoon and reconstruct temperatures from Simpson Lagoon sediments to evaluate the applicability of this proxy in Arctic estuarine environments. The Colville catchment soils, fluvial sediments, and estuarine sediments contain statistically similar brGDGT distributions, indicating that the brGDGTs throughout the system are soil derived with little alteration from in situ brGDGT production in the river or coastal waters. Temperatures reconstructed from the MBT'/CBT indices for surface samples show good agreement with regional summer (June through September) temperatures, suggesting a seasonal bias in Arctic temperature reconstructions from the Colville system. In addition, we reconstruct paleotemperatures from an estuarine sediment core that spans the last 75 years, revealing an overall warming trend in the twentieth century that is consistent with trends observed in regional instrumental records. These results support the application of this brGDGT-based paleotemperature proxy for subdecadal-scale summer temperature reconstructions in Arctic estuaries containing organic material derived from sediment-laden, episodic rivers.

  15. Bounded and unbounded boundaries - Untangling mechanisms for estuarine-marine ecological connectivity: Scales of m to 10,000 km - A review

    Science.gov (United States)

    Wolanski, Eric

    2017-11-01

    Recent advances in our understanding of the self-recruitment and connectivity of estuarine and coastal fauna and flora were made possible by an integration of physical oceanographic observations and modelling with results from studies of the behaviour of the seeds, eggs, larvae, propagules, juveniles and polyps, of population dynamics, microchemical tagging using natural and artificial markers, genetics and direct observations of trajectories. The species studied in those case studies were jellyfish in marine lakes, corals in acidified bays, seagrass, mangrove propagules, mussels and oysters, prawns, some estuarine fish larvae, the copepod Calanus finmarchius in the North Sea, sea turtles in the Coral Sea, and the ornate spiny lobster Panulirus ornatus in the Southeast Asia archipelago. The spatial scales for self-recruitment and connectivity vary with the species from a few m to 10,000 km, and the temporal scales vary from one to three generations. These studies suggest that, with increasing physical openness of a given site for a given species, self-recruiting increasingly relies on the behaviour of the species. Estuarine and coastal systems thus are simultaneously bounded and unbounded depending on the sites and the species considered and, although often ignored, the integration of oceanographic and behavioural understanding is increasingly required. This paper has shown the importance of understanding the hydrological and ecological dynamics with unbounded boundaries in creating the connectivity between parts of the aquatic continuum from the river catchment to the open seas.

  16. Linking Environmental Magnetism to Geochemical Studies and Management of Trace Metals. Examples from Fluvial, Estuarine and Marine Systems

    Directory of Open Access Journals (Sweden)

    Michael Scoullos

    2014-07-01

    Full Text Available Among the diverse research fields and wide range of studies encompassed by environmental magnetism, the present work elaborates on critical aspects of the geochemistry of trace metals that emerged through years of original research in a variety of environmental compartments. This review aims at sharing the insights gained on (a tracing metal pollution sources; and (b identifying processes and transport pathways from sources to depositional environments. Case studies on the Elefsis Gulf (Greece and the Gulf of Lions (France demonstrate the potential of combined magnetic measurements and chemical analysis to trace pollution signals resulting from land-based sources and atmospheric deposition. Case studies on estuarine environments, namely the Louros, Acheloos, and Asopos Estuaries (Greece, address modes of trace metal behavior under the influence of different hydrological regimes and elucidate in situ processes within the transitional estuarine zone, that define their ultimate fate. As sources, transport pathways, and processes of trace metals are fundamental in environmental management assessments, the involvement of magnetic measurements in the policy cycle could facilitate the development and implementation of appropriate regulatory measures for the integrated management of river basins, coastal, and marine areas.

  17. General assessment of estuarine pollution

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. General assessment of estuarine pollution. Contamination of estuaries by untreated domestic wastewater is widespread, however, in absence of time-series studies the responses of native flora and fauna to modified environment are unclear. Agricultural runoff ...

  18. Historic Habitat Opportunities and Food-Web Linkages of Juvenile Salmon in the Columbia River Estuary, Annual Report of Research.

    Energy Technology Data Exchange (ETDEWEB)

    Bottom, Daniel L.; Simenstad, Charles A.; Campbell, Lance [Northwest Fisheries Science Center

    2009-05-15

    In 2002 with support from the U.S. Army Corps of Engineers (USACE), an interagency research team began investigating salmon life histories and habitat use in the lower Columbia River estuary to fill significant data gaps about the estuary's potential role in salmon decline and recovery . The Bonneville Power Administration (BPA) provided additional funding in 2004 to reconstruct historical changes in estuarine habitat opportunities and food web linkages of Columbia River salmon (Onchorhynchus spp.). Together these studies constitute the estuary's first comprehensive investigation of shallow-water habitats, including selected emergent, forested, and scrub-shrub wetlands. Among other findings, this research documented the importance of wetlands as nursery areas for juvenile salmon; quantified historical changes in the amounts and distributions of diverse habitat types in the lower estuary; documented estuarine residence times, ranging from weeks to months for many juvenile Chinook salmon (O. tshawytscha); and provided new evidence that contemporary salmonid food webs are supported disproportionately by wetland-derived prey resources. The results of these lower-estuary investigations also raised many new questions about habitat functions, historical habitat distributions, and salmon life histories in other areas of the Columbia River estuary that have not been adequately investigated. For example, quantitative estimates of historical habitat changes are available only for the lower 75 km of the estuary, although tidal influence extends 217 km upriver to Bonneville Dam. Because the otolith techniques used to reconstruct salmon life histories rely on detection of a chemical signature (strontium) for salt water, the estuarine residency information we have collected to date applies only to the lower 30 or 35 km of the estuary, where fish first encounter ocean water. We lack information about salmon habitat use, life histories, and growth within the long tidal

  19. Cyanobacteria and cyanotoxins at the river-estuarine transition.

    Science.gov (United States)

    Bukaveckas, Paul A; Franklin, Rima; Tassone, Spencer; Trache, Brendan; Egerton, Todd

    2018-06-01

    We examined seasonal and longitudinal patterns in the occurrence of toxic cyanobacteria in the James River Estuary (Virginia). Highest chlorophyll and cyanobacteria levels were observed in the tidal freshwater segment, particularly during dry summers when freshwater replacement time was long. Cyanobacteria accounted for a small proportion of phytoplankton biomass (7-15%), and Microcystis comprised a small proportion of the cyanobacteria (85% of samples in July, August and September), fish tissues (87% of planktivorous fishes) and shellfish (83% of individuals). Generic indicators of algal blooms (chlorophyll and algal biomass) had limited utility for predicting microcystin concentrations. However, chlorophyll was found to be a useful predictor for the probability of exceeding specific toxin thresholds. Tissue microcystin concentrations were highest in fish and shellfish collected from the tidal fresh segment, but were detectable in biota collected from the oligohaline at distances 50 km seaward. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Estuarine geochemistry of 224Ra, 226Ra, and 222Rn

    International Nuclear Information System (INIS)

    Elsinger, R.J.

    1982-01-01

    Desorption from river borne sediments is the most likely source of the excess 226 Ra. Laboratory mixing experiments on Pee Dee River sediments show an increase in 226 Ra desorption with increasing salinities with maximum desorption occurring at or above 20 0 /oo salinity. Desorption and diffusion are the sources for 226 Ra in the estuarine systems. In Winyah Bay the 228 Ra/ 226 Ra activity ratio does not change significantly with salinity, averaging around 1.4, indicating desorption as the major source of 228 Ra. In the Yangtze River the 228 Ra/ 226 Ra activity ratio is constant (approx.1.90) until increasing linearly above 16 0 /oo. A diffusive flux from regeneration by 232 Th decay in shelf sediments is the source of the increase. In Delaware Bay 228 Ra increases faster than 226 Ra in the less than or equal to22 0 /oo water, indicating a source in addition to desorption. The increase can be balanced by a 0.33 dpm/cm 2 -year flux over the upper part of the Bay where fine grained sediments predominate. 224 Ra behavior is controlled by its 3.64 day half-life. In Winyah Bay a flux of around 0.4 dpm/cm 2 -day is necessary to support the standing crop of non-desorbed 224 Ra in the water column. In Delaware Bay the nearly constant 224 Ra in concentration over the 2.5 0 /oo to 12 0 /oo salinity range are maintained by regeneration from 228 Th in the turbidity maximum zones and diffusion from bottom sediments. Water leaving on ebb tide from a salt marsh on Delaware Bay had increases in all three radium isotopes ( 224 Ra > 228 Ra > 226 Ra) compared to water coming in on the flood tide. Excess 222 Rn concentrations in a fresh water section of the Pee Dee River show a decreasing downstream gradient. Using these gradients to determine evasion rates, stagnant film thicknesses range from 21μ to 62μ

  1. Distribution and diversity of copepods in the Mandovi-Zuari estuarine system, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    Truly estuarine and estuarine-marine species were the major components of copepods Neritic and limnetic species were stragglers in this environment and showed fortuitous distribution Monsoonal cycle induced seasonal rhythm on salinity and copepods...

  2. BOOK REVIEW: ESTUARINE SCIENCE: A SYNTHETIC APPROACH TO RESEARCH AND PRACTICE

    Science.gov (United States)

    This book is the product of fifty leading estuarine scientists most of whom attended a workshop convened for the purpose of "put[ting] together the case for synthesis of estuarine data and to show the capabilities of synthetic methods of research" (p. 2). The editor, John E. Hob...

  3. Effects of local and large-scale climate patterns on estuarine resident fishes: The example of Pomatoschistus microps and Pomatoschistus minutus

    Science.gov (United States)

    Nyitrai, Daniel; Martinho, Filipe; Dolbeth, Marina; Rito, João; Pardal, Miguel A.

    2013-12-01

    Large-scale and local climate patterns are known to influence several aspects of the life cycle of marine fish. In this paper, we used a 9-year database (2003-2011) to analyse the populations of two estuarine resident fishes, Pomatoschistus microps and Pomatoschistus minutus, in order to determine their relationships with varying environmental stressors operating over local and large scales. This study was performed in the Mondego estuary, Portugal. Firstly, the variations in abundance, growth, population structure and secondary production were evaluated. These species appeared in high densities in the beginning of the study period, with subsequent occasional high annual density peaks, while their secondary production was lower in dry years. The relationships between yearly fish abundance and the environmental variables were evaluated separately for both species using Spearman correlation analysis, considering the yearly abundance peaks for the whole population, juveniles and adults. Among the local climate patterns, precipitation, river runoff, salinity and temperature were used in the analyses, and North Atlantic Oscillation (NAO) index and sea surface temperature (SST) were tested as large-scale factors. For P. microps, precipitation and NAO were the significant factors explaining abundance of the whole population, the adults and the juveniles as well. Regarding P. minutus, for the whole population, juveniles and adults river runoff was the significant predictor. The results for both species suggest a differential influence of climate patterns on the various life cycle stages, confirming also the importance of estuarine resident fishes as indicators of changes in local and large-scale climate patterns, related to global climate change.

  4. Sediment-stabilizing and Destabilizing Ecoengineering Species from River to Estuary: the Case of the Scheldt System

    Science.gov (United States)

    Selakovic, S.; Cozzoli, F.; Leuven, J.; Van Braeckel, A.; Speybroeck, J.; Kleinhans, M. G.; Bouma, T.

    2017-12-01

    Interactions between organisms and landscape forming processes play an important role in evolution of coastal landscapes. In particular, biota has a strong potential to interact with important geomorphological processes such as sediment dynamics. Although many studies worked towards quantifying the impact of different species groups on sediment dynamics, information has been gathered on an ad hoc base. Depending on species' traits and distribution, functional groups of ecoengineering species may have differential effects on sediment deposition and erosion. We hypothesize that the spatial distributions of sediment-stabilizing and destabilizing species across the channel and along the whole salinity gradient of an estuary partly determine the planform shape and channel-shoal morphology of estuaries. To test this hypothesis, we analyze vegetation and macrobenthic data taking the Scheldt river-estuarine continuum as model ecosystem. We identify species traits with important effects on sediment dynamics and use them to form functional groups. By using linearized mixed modelling, we are able to accurately describe the distributions of the different functional groups. We observe a clear distinction of dominant ecosystem engineering functional groups and their potential effects on the sediment in the river-estuarine continuum. The first results of longitudinal cross section show the highest effects of stabilizing plant species in riverine and sediment bioturbators in weak polyhaline part of continuum. The distribution of functional groups in transverse cross sections shows dominant stabilizing effect in supratidal zone compared to dominant destabilizing effect in the lower intertidal zone. This analysis offers a new and more general conceptualization of distributions of sediment stabilizing and destabilizing functional groups and their potential impacts on sediment dynamics, shoal patterns, and planform shapes in river-estuarine continuum. We intend to test this in future

  5. Dissolved organic matter dynamics in the oligo/meso-haline zone of wetland-influenced coastal rivers

    Science.gov (United States)

    Maie, Nagamitsu; Sekiguchi, Satoshi; Watanabe, Akira; Tsutsuki, Kiyoshi; Yamashita, Youhei; Melling, Lulie; Cawley, Kaelin M.; Shima, Eikichi; Jaffé, Rudolf

    2014-08-01

    Wetlands are key components in the global carbon cycle and export significant amounts of terrestrial carbon to the coastal oceans in the form of dissolved organic carbon (DOC). Conservative behavior along the salinity gradient of DOC and chromophoric dissolved organic matter (CDOM) has often been observed in estuaries from their freshwater end-member (salinity = 0) to the ocean (salinity = 35). While the oligo/meso-haline (salinity DOC and CDOM optical properties determined by UV absorbance at 254 nm (A254) and excitation-emission matrix (EEM) fluorescence coupled with parallel factor analysis (PARAFAC) along the lower salinity range (salinity DOC and A254 was observed, while these parameters showed similar conservative behavior for the third. Three distinct EEM-PARAFAC models established for each of the rivers provided similar spectroscopic characteristics except for some unique fluorescence features observed for the Judan River. The distribution patterns of PARAFAC components suggested that the inputs from plankton and/or submerged aquatic vegetation can be important in the Bekanbeushi River. Further, DOM photo-products formed in the estuarine lake were also found to be transported upstream. In the Harney River, whereas upriver-derived terrestrial humic-like components were mostly distributed conservatively, some of these components were also derived from mangrove inputs in the oligo/meso-haline zone. Interestingly, fluorescence intensities of some terrestrial humic-like components increased with salinity for the Judan River possibly due to changes in the dissociation state of acidic functional groups and/or increase in the fluorescence quantum yield along the salinity gradient. The protein-like and microbial humic-like components were distributed differently between three wetland rivers, implying that interplay between loss to microbial degradation and inputs from diverse sources are different for the three wetland-influenced rivers. The results presented here

  6. Pollution biomarkers in estuarine animals: critical review and new perspectives.

    Science.gov (United States)

    Monserrat, José M; Martínez, Pablo E; Geracitano, Laura A; Amado, Lílian Lund; Martins, Camila Martinez Gaspar; Pinho, Grasiela Lopes Leães; Chaves, Isabel Soares; Ferreira-Cravo, Marlize; Ventura-Lima, Juliane; Bianchini, Adalto

    2007-01-01

    In this review, recent developments in monitoring toxicological responses in estuarine animals are analyzed, considering the biomarker responses to different classes of pollutants. The estuarine environment imposes stressful conditions to the organisms that inhabit it, and this situation can alter their sensitivity to many pollutants. The specificity of some biomarkers like metallothionein tissue concentration is discussed in virtue of its dependence on salinity, which is highly variable in estuaries. Examples of cholinesterase activity measurements are also provided and criteria to select sensitive enzymes to detect pesticides and toxins are discussed. Regarding non-specific biomarkers, toxic responses in terms of antioxidant defenses and/or oxidative damage are also considered in this review, focusing on invertebrate species. In addition, the presence of an antioxidant gradient along the body of the estuarine polychaete Laeonereis acuta (Nereididae) and its relationship to different strategies, which deal with the generation of oxidative stress, is reviewed. Also, unusual antioxidant defenses against environmental pro-oxidants are discussed, including the mucus secreted by L. acuta. Disruption of osmoregulation by pollutants is of paramount importance in several estuarine species. In some cases such as in the estuarine crab Chasmagnathus granulatus, there is a trade off between bioavailability of toxicants (e.g. metals) and their interaction with key enzymes such as Na(+)-K(+)-ATPase and carbonic anhydrase. Thus, the metal effect on osmoregulation is also discussed in the present review. Finally, field case studies with fish species like the croaker Micropogonias furnieri (Scianidae) are used to illustrate the application of DNA damage and immunosuppressive responses as potential biomarkers of complex mixture of pollutants.

  7. Tributyltin-resistant bacteria from estuarine and freshwater sediments.

    Science.gov (United States)

    Wuertz, S; Miller, C E; Pfister, R M; Cooney, J J

    1991-01-01

    Resistance to tributyltin (TBT) was examined in populations from TBT-polluted sediments and nonpolluted sediments from an estuary and from fresh water as well as in pure cultures isolated from those sediments. The 50% effective concentrations (EC50s) for populations were higher at a TBT-polluted freshwater site than at a site without TBT, suggesting that TBT selected for a TBT-resistant population. In contrast, EC50s were significantly lower for populations from a TBT-contaminated estuarine site than for those from a site without TBT, suggesting that other factors in addition to TBT determine whether populations become resistant. EC50s for populations from TBT-contaminated freshwater sediments were nearly 30 times higher than those for populations from TBT-contaminated estuarine sediments. We defined a TBT-resistant bacterium as one which grows on trypticase soy agar containing 8.4 microM TBT, a concentration which prevented the growth of 90% of the culturable bacteria from these sediments. The toxicity of TBT in laboratory media was influenced markedly by the composition of the medium and whether it was liquid or solid. Ten TBT-resistant isolates from estuarine sediments and 19 from freshwater sediments were identified to the genus level. Two isolates, each a Bacillus sp., may be the first gram-positive bacteria isolated from fresh water in the presence of a high concentration of TBT. There was a high incidence of resistance to heavy metals: metal resistance indices were 0.76 for estuarine isolates and 0.68 for freshwater isolates.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1746939

  8. Estuarine and marine geology (2011-2015)

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Chakraborty, P.

    . Detailed studies on rock-magnetic properties and delta 13Corg in sediments off the Krishna-Godavari provide evidence of reductive diagenesis, formation of authigenic sulfides and occurrence of methane in these estuarine sediments and also...

  9. Environmental risk assessment of cobalt and manganese from industrial sources in an estuarine system.

    Science.gov (United States)

    Barrio-Parra, F; Elío, J; De Miguel, E; García-González, J E; Izquierdo, M; Álvarez, R

    2018-04-01

    A total of 74 samples of soil, sediment, industrial sludge, and surface water were collected in a Mediterranean estuarine system in order to assess the potential ecological impact of elevated concentrations of Co and Mn associated with a Terephthalic (PTA) and Isophthalic (PIPA) acids production plant. Samples were analyzed for elemental composition (37 elements), pH, redox potential, organic carbon, and CaCO 3 content, and a group of 16 selected samples were additionally subjected to a Tessier sequential extraction. Co and Mn soil concentrations were significantly higher inside the industrial facility and around its perimeter than in background samples, and maximum dissolved Co and Mn concentrations were found in a creek near the plant's discharge point, reaching values 17,700 and 156 times higher than their respective background concentrations. The ecological risk was evaluated as a function of Co and Mn fractionation and bioavailability which were controlled by the environmental conditions generated by the advance of seawater into the estuarine system during high tide. Co appeared to precipitate near the river mouth due to the pH increase produced by the influence of seawater intrusion, reaching hazardous concentrations in sediments. In terms of their bioavailability and the corresponding risk assessment code, both Co and Mn present sediment concentrations that result in medium to high ecological risk whereas water concentrations of both elements reach values that more than double their corresponding Secondary Acute Values.

  10. Estuarine beaches of the Amazon coast: environmental and recreational characterization

    OpenAIRE

    de Sousa, Rosigleyse C.; Pereira, Luci Cajueiro Carneiro; Jiménez Quintana, José Antonio

    2016-01-01

    The Amazon coast is rich in natural resources, with highly valued natural landscapes and ecological systems. These environments include estuarine beaches, which are important areas for recreational activities. The present study provides an environmental and recreational diagnosis of three of these estuarine beaches on the Amazon coast (Colares, Maruda, and Murubira). The study was conducted in July, 2012, 2013 and 2015. An set of variables was assessed: (i) physical variables (hydrodynamics),...

  11. Satellite Derived Water Quality Observations Are Related to River Discharge and Nitrogen Loads in Pensacola Bay, Florida

    Directory of Open Access Journals (Sweden)

    John C. Lehrter

    2017-09-01

    Full Text Available Relationships between satellite-derived water quality variables and river discharges, concentrations and loads of nutrients, organic carbon, and sediments were investigated over a 9-year period (2003–2011 in Pensacola Bay, Florida, USA. These analyses were conducted to better understand which river forcing factors were the primary drivers of estuarine variability in several water quality variables. Remote sensing reflectance time-series data were retrieved from the MEdium Resolution Imaging Spectrometer (MERIS and used to calculate monthly and annual estuarine time-series of chlorophyll a (Chla, colored dissolved organic matter (CDOM, and total suspended sediments (TSS. Monthly MERIS Chla varied from 2.0 mg m−3 in the lower region of the bay to 17.2 mg m−3 in the upper bay. MERIS CDOM and TSS exhibited similar patterns with ranges of 0.51–2.67 (m−1 and 0.11–8.9 (g m−3. Variations in the MERIS-derived monthly and annual Chla, CDOM, and TSS time-series were significantly related to monthly and annual river discharge and loads of nitrogen, organic carbon, and suspended sediments from the Escambia and Yellow rivers. Multiple regression models based on river loads (independent variables and MERIS Chla, CDOM, or TSS (dependent variables explained significant fractions of the variability (up to 62% at monthly and annual scales. The most significant independent variables in the regressions were river nitrogen loads, which were associated with increased MERIS Chla, CDOM, and TSS concentrations, and river suspended sediment loads, which were associated with decreased concentrations. In contrast, MERIS water quality variations were not significantly related to river total phosphorus loads. The spatially synoptic, nine-year satellite record expanded upon the spatial extent of past field studies to reveal previously unseen system-wide responses to river discharge and loading variation. The results indicated that variations in Pensacola Bay Chla

  12. Studies on growth and age of bivalves from temperate and tropical estuarine ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.

    Comparison of growth progression and age composition of Abra alba and Nuculana minuta from temperate estuarine ecosystem with Meretrix casta and Paphia malabarica from tropical estuarine environment, revealed that the annual growth rate in tropical...

  13. Stratification and salt-wedge in the Seomjin river estuary under the idealized tidal influence

    Science.gov (United States)

    Hwang, Jin Hwan; Jang, Dongmin; Kim, Yong Hoon

    2017-12-01

    Advection, straining, and vertical mixing play primary roles in the process of estuarine stratification. Estuaries can be classified as salt-wedge, partially-mixed or well-mixed depending on the vertical density structure determined by the balancing of advection, mixing and straining. In particular, straining plays a major role in the stratification of the estuarine water body along the estuarine channel. Also, the behavior of a salt wedge with a halocline shape in a stratified channel can be controlled by the competition between straining and mixing induced by buoyancy from the riverine source and tidal forcing. The present study uses Finite Volume Coastal Ocean Model (FVCOM) to show that straining and vertical mixing play major roles in controlling along-channel flow and stratification structures in the Seomjin river estuary (SRE) under idealized conditions. The Potential Energy Anomaly (PEA) dynamic equation quantifies the governing processes thereby enabling the determination of the stratification type. By comparing terms in the equation, we examined how the relative strengths of straining and mixing alter the stratification types in the SRE due to changes in river discharge and the depth resulting from dredging activities. SRE under idealized tidal forcing tends to be partially-mixed based on an analysis of the balance between terms and the vertical structure of salinity, and the morphological and hydrological change in SRE results in the shift of stratification type. While the depth affects the mixing, the freshwater discharge mainly controls the straining, and the balance between mixing and straining determines the final state of the stratification in an estuarine channel. As a result, the development and location of a salt wedge along the channel in a partially mixed and highly stratified condition is also determined by the ratio of straining to mixing. Finally, our findings confirm that the contributions of mixing and straining can be assessed by using the

  14. Minimal incorporation of Deepwater Horizon oil by estuarine filter feeders

    International Nuclear Information System (INIS)

    Fry, Brian; Anderson, Laurie C.

    2014-01-01

    Highlights: • Oil from the Deepwater Horizon oil spill entered Louisiana bays in mid-2010. • Oil was used minimally (<1%) in diets of mussels and barnacles. • Also, oil did not enhance planktonic respiration rates. • Use of oil carbon was relatively small in these productive estuarine food webs. - Abstract: Natural abundance carbon isotope analyses are sensitive tracers for fates and use of oil in aquatic environments. Use of oil carbon in estuarine food webs should lead to isotope values approaching those of oil itself, −27‰ for stable carbon isotopes reflecting oil origins and −1000‰ for carbon-14 reflecting oil age. To test for transfer of oil from the 2010 Deepwater Horizon spill into estuarine food webs, filter-feeding barnacles (Balanus sp.) and marsh mussels (Geukensia demissa) were collected from Louisiana estuaries near the site of the oil spill. Carbon-14 analyses of these animals from open waters and oiled marshes showed that oil use was <1% and near detection limits estimated at 0.3% oil incorporation. Respiration studies showed no evidence for enhanced microbial activity in bay waters. Results are consistent with low dietary impacts of oil for filter feeders and little overall impact on respiration in the productive Louisiana estuarine systems

  15. Estuarine characteristics of the lower reaches of the River Periyar (Cochin backwater)

    Digital Repository Service at National Institute of Oceanography (India)

    Sankaranarayanan, V.N.; Varma, P.U.; Balachandran, K.K.; Pylee, A.; Joseph, T.

    Lower reaches of river Periyar were studied to assess longitudinal extent of salt water intrusion into the system during different seasons and also its effect on the flushing of pollutants introduced by the industries. During SW monsoon season due...

  16. GoM Coastal and Estuarine Biopsy Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Small vessel surveys are conducted within estuarine and nearshore coastal waters to collect tissue biopsy samples from bottlenose dolphins. Visual surveys are...

  17. A user's guide to coping with estuarine management bureaucracy: An Estuarine Planning Support System (EPSS) tool.

    Science.gov (United States)

    Lonsdale, Jemma; Nicholson, Rose; Weston, Keith; Elliott, Michael; Birchenough, Andrew; Sühring, Roxana

    2018-02-01

    Estuaries are amongst the most socio-economically and ecologically important environments however, due to competing and conflicting demands, management is often challenging with a complex legislative framework managed by multiple agencies. To facilitate the understanding of this legislative framework, we have developed a GISbased Estuarine Planning Support System tool. The tool integrates the requirements of the relevant legislation and provides a basis for assessing the current environmental state of an estuary as well as informing and assessing new plans to ensure a healthy estuarine state. The tool ensures that the information is easily accessible for regulators, managers, developers and the public. The tool is intended to be adaptable, but is assessed using the Humber Estuary, United Kingdom as a case study area. The successful application of the tool for complex socio-economic and environmental systems demonstrates that the tool can efficiently guide users through the complex requirements needed to support sustainable development. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  18. Physical aspects of estuarine pollution - A case study in Amba river estuary

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.; Josanto, V.; Sarma, R.V.; Zingde, M.D.

    Tide dominated Amba river estuary was studied to evaluate it's physical characteristics with a point on application to locate a suitable release point of industrial effluents. It is important to site the outfall in a manner ensuring that the water...

  19. Seasonal Changes in Estuarine Dissolved Organic Matter Due to Variations in Discharge, Flushing Times and Wind-driven Mixing Events

    Science.gov (United States)

    Dixon, Jennifer Louise

    isotopes (Bauer, 2002) and lignin (e.g., Benner and Opsahl, 2001; Harvey and Mannino, 2001). Marine DOM derived from phytoplankton typically has carbon stable isotope (delta13C) values that range from --20 to --22‰, while terrestrial DOM derived from C3 land plants typically have delta13C values that range from --26 to --28‰ (Bauer, 2002). Lignin is an important component of vascular plants, thus making it a unique geochemical biomarker, which can be used to trace the fate of terrestrial DOM in coastal seawater (e.g., Hernes and Benner, 2003; Walker et al. 2009; Osburn and Stedmon, 2011). Further, the ratios of the different phenolic compounds derived from the oxidation of lignin can be used to distinguish between plant sources (e.g. angiosperm vs. gymnosperm, or woody vs. non-woody tissue) and the extent of exposure to degradation (Hedges et al. 1988). The highly productive, eutrophic waters of the Neuse River Estuary (NRE), in eastern North Carolina, USA, serve as a transition zone for terrigenous DOM between the head of the Neuse River and Pamlico Sound. Previous studies have determined that the NRE is dominated by inputs from riverine discharge, yet very clear shifts in DOM quality are apparent as discharge varied (Paerl et al. 1998; Osburn et al. 2012). Furthermore, flushing times within the NRE will aid in determining whether DOM is primarily autochthonous or allochthonous and if it is processed internally or transported downstream to the Pamlico Sound (Paerl et al. 1998; Mari et al. 2007, Peierls et al. 2012). Therefore, the main sources of DOM and its composition can change throughout an estuary depending on the hydrodynamic conditions. For example, increases in flushing time may allow for the accumulation of autochthonous DOM because of (1) planktonic communities within the water column having more time to utilize nutrients within the system, resulting in phytoplankton blooms and (2) lower inputs of allochthonous OM from the NRE's watershed (Dixon et al

  20. Estuarine modification of dissolved and particulate trace metals in major rivers of East-Hainan, China

    Science.gov (United States)

    Fu, Jun; Tang, Xiao-Liang; Zhang, Jing; Balzer, Wolfgang

    2013-04-01

    Dissolved and particulate cadmium, copper, iron, lead, cobalt and nickel were analyzed in surface waters of the Wanquan River estuary and the Wenchang/Wenjiao River estuary in East-Hainan Island during the dry season (December 2006) and two wet seasons (August 2007 and July/August 2008). A major difference to other Chinese rivers was the very low concentration of suspended particles in these tropical Hainan estuaries. In the dissolved phase, a positive deviation from the theoretical dilution line was observed for Cd during different expeditions. Dissolved Cu and Ni essentially behaved conservatively, while Fe, Pb and partly also Co correlated in their negative deviation from simple mixing. Strong seasonal variability was observed only for dissolved Fe, Pb and Cd: sorption by the much higher loading with suspended particles during the dry season lead to a strong lowering of dissolved Fe and Pb, while the opposite was observed for dissolved Cd. In both estuaries all six metals in particulate form showed almost constant values with a tendency for slight decreases along the salinity profile. The normalization to particulate Al revealed some specific particle properties during the different expeditions. The dynamics of Fe chemistry dominated the distribution of Pb in all forms. The distribution coefficients KD showed a general decrease in the order Fe>Pb>Co>Ni>Cu≈Cd. There was no "particle concentration effect"; rather the KD's of Fe and Pb exhibited slightly positive correlations with the suspended particle loadings. Elevated concentrations levels in the Wenchang/Wenjiao river estuary, especially during the wet season 2008, were ascribed to diffuse inputs from aquaculture ponds which girdle the upper estuary. In comparison to major Chinese rivers, the tropical Hainan estuaries (S>0) showed similar levels for Cd, Cu, Pb, Co and Ni in particles and solution, while Fe was enriched in both matrices. On a global scale, neither in the Wanquan river estuary nor in the

  1. Coastal Wetlands Protection Act: Case of Apalachicola-Chattahoochee-Flint (ACF) River

    OpenAIRE

    Latif Gürkan KAYA

    2007-01-01

    Coastal wetlands, being important components of estuarine and coastal systems, stand for all publicly owned lands subject to the ebb and flow of the tide. They are below the watermark of ordinary high tide. The coastal wetlands contain a vital natural resource system. The coastal wetlands resource system, unless impossible, to reconstruct or rehabilitate once adversely affected by human. In the USA, the Apalachicola-Chattahoochee-Flint (ACF) river states (i.e. Georgia, Alabama and Florida) ha...

  2. Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

    NARCIS (Netherlands)

    Booij, P; Sjollema, S.B.; van der Geest, H.G.; Leonards, P.E.G.; Lamoree, M.H.; de Voogt, W.P.; Admiraal, W.; Laane, R.W.P.M.; Vethaak, A.D.

    2015-01-01

    For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and

  3. Benthic infaunal community structuring in an acidified tropical estuarine system.

    Science.gov (United States)

    Hossain, M Belal; Marshall, David J

    2014-01-01

    Recent studies suggest that increasing ocean acidification (OA) should have strong direct and indirect influences on marine invertebrates. While most theory and application for OA is based on relatively physically-stable oceanic ecological systems, less is known about the effects of acidification on nearshore and estuarine systems. Here, we investigated the structuring of a benthic infaunal community in a tropical estuarine system, along a steep salinity and pH gradient, arising largely from acid-sulphate groundwater inflows (Sungai Brunei Estuary, Borneo, July 2011- June 2012). Preliminary data indicate that sediment pore-water salinity (range: 8.07 - 29.6 psu) declined towards the mainland in correspondence with the above-sediment estuarine water salinity (range: 3.58 - 31.2 psu), whereas the pore-water pH (range: 6.47- 7.72) was generally lower and less variable than the estuarine water pH (range: 5.78- 8.3), along the estuary. Of the thirty six species (taxa) recorded, the polychaetes Neanthes sp., Onuphis conchylega, Nereididae sp. and the amphipod Corophiidae sp., were numerically dominant. Calcified microcrustaceans (e.g., Cyclopoida sp. and Corophiidae sp.) were abundant at all stations and there was no clear distinction in distribution pattern along the estuarine between calcified and non-calcified groups. Species richness increased seawards, though abundance (density) showed no distinct directional trend. Diversity indices were generally positively correlated (Spearman's rank correlation) with salinity and pH (p 0.05). Three faunistic assemblages were distinguished: (1) nereid-cyclopoid-sabellid, (2) corophiid-capitellid and (3) onuphid- nereid-capitellid. These respectively associated with lower salinity/pH and a muddy bottom, low salinity/pH and a sandy bottom, and high salinity/pH and a sandy bottom. However, CCA suggested that species distribution and community structuring is more strongly influenced by sediment particle characteristics than by the

  4. Use of mineral magnetic concentration data as a particle size proxy: a case study using marine, estuarine and fluvial sediments in the Carmarthen Bay area, South Wales, U.K.

    Science.gov (United States)

    Booth, C A; Walden, J; Neal, A; Smith, J P

    2005-07-15

    Compositional (non-magnetic) data can correlate strongly with particle size, which deems it appropriate as a particle size proxy and, therefore, a reliable means of normalising analytical data for particle size effects. Previous studies suggest magnetic concentration parameters represent an alternative means of normalising for these effects and, given the speed, low-cost and sensitivity of the measurements may, therefore, offer some advantages over other compositional signals. In this work, contemporary sediments from a range of depositional environments have been analysed with regard to their mineral magnetic concentration and textural characteristics, to observe if the strength and nature of the relationship identified in previous studies is universal. Our data shows magnetic parameters (chi(LF), chi(ARM) and SIRM) possess contrasting relationships with standard textural parameters for sediment samples collected from marine (Carmarthen Bay), estuarine (Gwendraeth Estuary) and fluvial (Rivers Gwendraeth Fach and Gwendraeth Fawr) settings. Magnetic concentrations of sediments from both the marine and estuarine environments are highly influenced by the magnetic contribution of finer particle sizes; Gwendraeth Fawr River sediments are influenced by the magnetic contribution of coarser particle sizes, while sediments from the Gwendraeth Fach River are not influenced significantly by any variations in textural properties. These results indicate mineral magnetic measurements have considerable potential as a particle size proxy for particular sedimentary environments, which in certain instances could be useful for geochemical, sediment transport, and sediment provenance studies. However, the data also highlight the importance of fully determining the nature of the relationship between sediment particle size and magnetic properties before applying mineral magnetic data as a particle size proxy.

  5. Polycyclic aromatic hydrocarbons (PAH) in superficial water from a tropical estuarine system: Distribution, seasonal variations, sources and ecological risk assessment.

    Science.gov (United States)

    Santos, Ewerton; Souza, Michel R R; Vilela Junior, Antônio R; Soares, Laiane S; Frena, Morgana; Alexandre, Marcelo R

    2018-02-01

    This study aimed to evaluate the PAH distribution, sources, seasonal variations and ecological risk assessment in superficial water from the Japaratuba River, Brazil. PAH concentrations ranged from 4 to 119ngL -1 . It was observed that the PAH total concentrations and profiles showed significant differences when comparing the dry season (summer) with the rainy season (winter). Furthermore, most of the PAH originated from pyrogenic sources in the winter, whereas a mixture of sources was observed in the summer. PAH concentration levels found in this study were considered lower than those obtained in other estuarine systems. Ecological risk assessment was determined for individual PAH, based on the risk quotient (RQ) to evaluate the risk of aquatic biota's exposure to PAH. Results suggested that the Japaratuba River has achieved a moderate degree of ecological risk for high molecular weight, showing the importance of identifying these carcinogenic and mutagenic compounds in aquatic systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Seasonal variability of salinity and circulation in a silled estuarine fjord: A numerical model study

    Science.gov (United States)

    Kawase, Mitsuhiro; Bang, Bohyun

    2013-12-01

    A three-dimensional hydrodynamic model is used to study seasonal variability of circulation and hydrography in Hood Canal, Washington, United States, an estuarine fjord that develops seasonally hypoxic conditions. The model is validated with data from year 2006, and is shown to be capable of quantitatively realistic simulation of hydrographic variability. Sensitivity experiments show the largest cause of seasonal variability to be that of salinity at the mouth of the fjord, which drives an annual deep water renewal in late summer-early autumn. Variability of fresh water input from the watershed also causes significant but secondary changes, especially in winter. Local wind stress has little effect over the seasonal timescale. Further experiments, in which one forcing parameter is abruptly altered while others are kept constant, show that outside salinity change induces an immediate response in the exchange circulation that, however, decays as a transient as the system equilibrates. In contrast, a change in the river input initiates gradual adjustment towards a new equilibrium value for the exchange transport. It is hypothesized that the spectral character of the system response to river variability will be redder than to salinity variability. This is demonstrated with a stochastically forced, semi-analytical model of fjord exchange circulation. While the exchange circulation in Hood Canal appears less sensitive to the river variability than to the outside hydrography at seasonal timescales, at decadal and longer timescales both could become significant factors in affecting the exchange circulation.

  7. Drivers of change in estuarine-coastal ecosystems: Discoveries from four decades of study in San Francisco Bay

    Science.gov (United States)

    Cloern, J.E.; Jassby, A.D.

    2012-01-01

    Poised at the interface of rivers, ocean, atmosphere and dense human settlement, estuaries are driven by a large array of natural and anthropogenic forces. San Francisco Bay exemplifies the fast-paced change occurring in many of the world's estuaries, bays and inland seas in response to these diverse forces. We use observations from this particularly well-studied estuary to illustrate responses to six drivers that are common agents of change where land and sea meet: water consumption and diversion; human modification of sediment supply; introduction of non-native species; sewage input; environmental policy; and climate shifts. In San Francisco Bay, responses to these drivers include, respectively, shifts in the timing and extent of freshwater inflow and salinity intrusion; decreasing turbidity; restructuring of plankton communities; nutrient enrichment; elimination of hypoxia and reduced metal contamination of biota; and food web changes that decrease resistance of the estuary to nutrient pollution. Detection of these changes and discovery of their causes through environmental monitoring have been essential for establishing and measuring outcomes of environmental policies that aim to maintain high water quality and sustain services provided by estuarine-coastal ecosystems. The wide range of variability time scales and the multiplicity of interacting drivers place heavy demands on estuarine monitoring programs. But the San Francisco Bay case study illustrates why the imperative for monitoring has never been greater.

  8. Drivers of change in estuarine-coastal ecosystems: Discoveries from four decades of study in San Francisco Bay

    Science.gov (United States)

    Cloern, James E.; Jassby, Alan D.

    2012-12-01

    Poised at the interface of rivers, ocean, atmosphere and dense human settlement, estuaries are driven by a large array of natural and anthropogenic forces. San Francisco Bay exemplifies the fast-paced change occurring in many of the world's estuaries, bays, and inland seas in response to these diverse forces. We use observations from this particularly well-studied estuary to illustrate responses to six drivers that are common agents of change where land and sea meet: water consumption and diversion, human modification of sediment supply, introduction of nonnative species, sewage input, environmental policy, and climate shifts. In San Francisco Bay, responses to these drivers include, respectively, shifts in the timing and extent of freshwater inflow and salinity intrusion, decreasing turbidity, restructuring of plankton communities, nutrient enrichment, elimination of hypoxia and reduced metal contamination of biota, and food web changes that decrease resistance of the estuary to nutrient pollution. Detection of these changes and discovery of their causes through environmental monitoring have been essential for establishing and measuring outcomes of environmental policies that aim to maintain high water quality and sustain services provided by estuarine-coastal ecosystems. The many time scales of variability and the multiplicity of interacting drivers place heavy demands on estuarine monitoring programs, but the San Francisco Bay case study illustrates why the imperative for monitoring has never been greater.

  9. Coastal Wetlands Protection Act: Case of Apalachicola-Chattahoochee-Flint (ACF River

    Directory of Open Access Journals (Sweden)

    Latif Gürkan KAYA

    2007-01-01

    Full Text Available Coastal wetlands, being important components of estuarine and coastal systems, stand for all publicly owned lands subject to the ebb and flow of the tide. They are below the watermark of ordinary high tide. The coastal wetlands contain a vital natural resource system. The coastal wetlands resource system, unless impossible, to reconstruct or rehabilitate once adversely affected by human. In the USA, the Apalachicola-Chattahoochee-Flint (ACF river states (i.e. Georgia, Alabama and Florida have variation in the structure and the function of their wetland program affecting the ACF river basins' wetlands. Although some states have no special wetlands program, they have permits and water quality certification for these areas. Some state programs affect state agencies while local government implements other programs.

  10. Impacts of Suspended Sediment and Estuarine - Shelf Exchange Pathways on Shelf Ecosystem Dynamics in the Northern Gulf of Mexico

    Science.gov (United States)

    Wiggert, J. D.; Pan, C.; Dinniman, M. S.; Lau, Y.; Fitzpatrick, P. J.; O'Brien, S. J.; Bouchard, C.; Quas, L. M.; Miles, T. N.; Cambazoglu, M. K.; Dykstra, S. L.; Dzwonkowski, B.; Jacobs, G. A.; Church, I.; Hofmann, E. E.

    2017-12-01

    A circulation model based on the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System, with coupled biogeochemical and sediment transport modules, has been implemented for Mississippi Sound and the adjacent continental shelf region. The model has 400-m horizontal resolution, 24 vertical layers, and includes wetting/drying capability to resolve shallow inshore regions. The circulation model was spun-up using oceanographic initial and lateral boundary conditions provided by a 1-km resolution regional implementation of the Navy Coastal Ocean Model (NCOM) in the Gulf of Mexico. The biogeochemical module includes multiple size classes of phytoplankton, zooplankton and detritus, a fish larvae compartment, and explicitly tracks dissolved oxygen with benthic cycling interaction. The sediment transport model is implemented based on benthic mapping data that provides bottom sediment type distributions and spatio-temporal validation. A regionally specific atmospheric forcing product that provides improved spatial and temporal resolution, including diurnal sea breeze impacts, has been developed and applied. Model experiments focus on periods when comprehensive ship-based sampling was deployed by the CONCORDE (Consortium for Coastal River-Dominated Ecosystems) research program, which was established to investigate the complex fine-scale biological, chemical and physical interactions in a marine system controlled by pulsed-river plume dynamics. Biophysical interactions and biogeochemical variability associated with estuarine - shelf exchanges between nearshore lagoonal estuarine waters and the continental shelf revealed by the model provide new insight into how seasonal variation of hydrological forcing conditions influence ecological and biogeochemical processes in the highly productive Northern Gulf region. Application of the COAWST-based model system with and without inclusion of the sediment transport module demonstrates how suspended sediment in the

  11. Toward Understanding the Dynamics of Microbial Communities in an Estuarine System

    KAUST Repository

    Zhang, Weipeng; Bougouffa, Salim; Wang, Yong; Lee, On On; Yang, Jiangke; Chan, Colin; Song, Xingyu; Qian, Pei-Yuan

    2014-01-01

    Community assembly theories such as species sorting theory provide a framework for understanding the structures and dynamics of local communities. The effect of theoretical mechanisms can vary with the scales of observation and effects of specific environmental factors. Based on 16S rRNA gene tag pyrosequencing, different structures and temporal succession patterns were discovered between the surface sediments and bottom water microbial communities in the Pearl River Estuary (PRE). The microbial communities in the surface sediment samples were more diverse than those in the bottom water samples, and several genera were specific for the water or sediment communities. Moreover, water temperature was identified as the main variable driving community dynamics and the microbial communities in the sediment showed a greater temporal change. We speculate that nutrient-based species sorting and bacterial plasticity to the temperature contribute to the variations observed between sediment and water communities in the PRE. This study provides a more comprehensive understanding of the microbial community structures in a highly dynamic estuarine system and sheds light on the applicability of ecological theoretical mechanisms.

  12. Toward understanding the dynamics of microbial communities in an estuarine system.

    Directory of Open Access Journals (Sweden)

    Weipeng Zhang

    Full Text Available Community assembly theories such as species sorting theory provide a framework for understanding the structures and dynamics of local communities. The effect of theoretical mechanisms can vary with the scales of observation and effects of specific environmental factors. Based on 16S rRNA gene tag pyrosequencing, different structures and temporal succession patterns were discovered between the surface sediments and bottom water microbial communities in the Pearl River Estuary (PRE. The microbial communities in the surface sediment samples were more diverse than those in the bottom water samples, and several genera were specific for the water or sediment communities. Moreover, water temperature was identified as the main variable driving community dynamics and the microbial communities in the sediment showed a greater temporal change. We speculate that nutrient-based species sorting and bacterial plasticity to the temperature contribute to the variations observed between sediment and water communities in the PRE. This study provides a more comprehensive understanding of the microbial community structures in a highly dynamic estuarine system and sheds light on the applicability of ecological theoretical mechanisms.

  13. Toward Understanding the Dynamics of Microbial Communities in an Estuarine System

    KAUST Repository

    Zhang, Weipeng

    2014-04-14

    Community assembly theories such as species sorting theory provide a framework for understanding the structures and dynamics of local communities. The effect of theoretical mechanisms can vary with the scales of observation and effects of specific environmental factors. Based on 16S rRNA gene tag pyrosequencing, different structures and temporal succession patterns were discovered between the surface sediments and bottom water microbial communities in the Pearl River Estuary (PRE). The microbial communities in the surface sediment samples were more diverse than those in the bottom water samples, and several genera were specific for the water or sediment communities. Moreover, water temperature was identified as the main variable driving community dynamics and the microbial communities in the sediment showed a greater temporal change. We speculate that nutrient-based species sorting and bacterial plasticity to the temperature contribute to the variations observed between sediment and water communities in the PRE. This study provides a more comprehensive understanding of the microbial community structures in a highly dynamic estuarine system and sheds light on the applicability of ecological theoretical mechanisms.

  14. Science partnership between U.S. Geological Survey and the Lower Elwha Klallam Tribe—Understanding the Elwha River Dam Removal Project

    Science.gov (United States)

    Duda, Jeffrey J.; Beirne, Matt M.; Warrick, Jonathan A.; Magirl, Christopher S.

    2018-04-16

    After nearly a century of producing power, two large hydroelectric dams on the Elwha River in Washington State were removed during 2011 to 2014 to restore the river ecosystem and recover imperiled salmon populations. Roughly two-thirds of the 21 million cubic meters of sediment—enough to fill nearly 2 million dump trucks—contained behind the dams was released downstream, which restored natural processes and initiated important changes to the river, estuarine, and marine ecosystems. A multidisciplinary team of scientists from the Lower Elwha Klallam Tribe, academia, non-governmental organizations, Federal and state agencies, and the U.S. Geological Survey collected key data before, during, and after dam removal to understand the outcomes of this historic project on the Elwha River ecosystem.

  15. Evaluation of Marsh/Estuarine Water Quality and Ecological Models: An Interim Guide

    Science.gov (United States)

    1982-01-01

    benthic oxygen demand, benthic scour and deposition, photosynthesis and respiration of aquatic plants, and nitrification (Dobbins 1964; O’Connor 1967... photosynthesis , algal respiration, decom- position, and mixing processes play dominant roles, the understanding and characterization of significant pro...Adams, S. M. 1979. "A Mathematical Model of Trophic Dynamics in Estuarine Seagrass Communities," Marsh-Estuarine Systems Simulation, Dame, R. F., ed

  16. The Abundance and Activity of Nitrate-Reducing Microbial Populations in Estuarine Sediments

    Science.gov (United States)

    Cardarelli, E.; Francis, C. A.

    2014-12-01

    Estuaries are productive ecosystems that ameliorate nutrient and metal contaminants from surficial water supplies. At the intersection of terrestrial and aquatic environments, estuarine sediments host major microbially-mediated geochemical transformations. These include denitrification (the conversion of nitrate to nitrous oxide and/or dinitrogen) and dissimilatory nitrate reduction to ammonium (DNRA). Denitrification has historically been seen as the predominant nitrate attenuation process and functions as an effective sink for nitrate. DNRA has previously been believed to be a minor nitrate reduction process and transforms nitrate within the ecosystem to ammonium, a more biologically available N species. Recent studies have compared the two processes in coastal environments and determined fluctuating environmental conditions may suppress denitrification, supporting an increased role for DNRA in the N cycle. Nitrate availability and salinity are factors thought to influence the membership of the microbial communities present, and the nitrate reduction process that predominates. The aim of this study is to investigate how nitrate concentration and salinity alter the transcript abundances of N cycling functional gene markers for denitrification (nirK, nirS) and DNRA (nrfA) in estuarine sediments at the mouth of the hypernutrified Old Salinas River, CA. Short-term whole core incubations amended with artificial freshwater/artificial seawater (2 psu, 35 psu) and with varying NO3- concentrations (200mM, 2000mM) were conducted to assess the activity as well as the abundance of the nitrate-reducing microbial populations present. Gene expression of nirK, nirS, and nrfA at the conclusion of the incubations was quantified using reverse transcription quantitative polymerase chain reaction (RT-qPCR). High abundances of nirK, nirS, and nrfA under particular conditions coupled with the resulting geochemical data ultimately provides insight onto how the aforementioned factors

  17. Effect of river discharge and geometry on tides and net water transport in an estuarine network, an idealized model applied to the Yangtze Estuary

    NARCIS (Netherlands)

    Alebregtse, N. C.|info:eu-repo/dai/nl/345704304; de Swart, H. E.|info:eu-repo/dai/nl/073449725

    2016-01-01

    Tidal propagation in, and division of net water transport over different channels in an estuarine network are analyzed using a newly developed idealized model. The water motion in this model is governed by the cross-sectionally averaged shallow water equations and is forced by tides at the seaward

  18. San Jacinto River oil spill: wetland bioremediation project

    International Nuclear Information System (INIS)

    Mills, M.A.; Bonner, J.S.

    1996-01-01

    Gasoline, diesel and unrefined Arabian light crude oil were accidentally released into the San Jacinto River after a series of pipelines ruptured. Natural removal processes (volatilization, dissolution, weathering), fire, and the spill clean-up effort, removed approximately 95% of the petroleum. The area where residual oil was found was an estuarine wetland on the lower San Jacinto River. Samples were collected from 21 study areas and an evaluation of the varying levels of bioremediation was conducted. Phase one has been completed and involved the evaluation of the natural recovery of oil from the spill. Phase two was still in progress and involved the addition of inorganic nutrients and the alternate electron acceptor to enhance the biodegradation of the petroleum. Results showed that biodegradation was responsible for much of the reduction of certain components in petroleum within the first 150 days. 12 refs., 8 figs

  19. Delivery and fate of fluvial water and sediment to the sea: a marine geologist's view of European rivers

    Directory of Open Access Journals (Sweden)

    John D. Milliman

    2001-12-01

    Full Text Available Despite their relatively small drainage areas, European rivers reflect a wide variety of hydrologic regimes, although with very few exceptions they have been strongly affected by human activity. Scandinavian rivers (particularly those draining Iceland and western Norway can have high runoff, and, except for those draining Iceland, all have very low suspended and dissolved sediment loads. Northern and western European rivers have somewhat lower runoff, among the lowest suspended sediment yields in the world, and anthropogenically enhanced dissolved solid loads. Annual discharge of many of these rivers appears to vary inversely with the North Atlantic Oscillation index. Rivers discharging from the southern Alps into the Mediterranean Sea have relatively high runoff, high suspended sediment yields (reflecting younger, more easily erodable rocks as well as generally smaller drainage basins, and high dissolved yields, although presumably with somewhat less human influence. European rivers and their estuaries tend to reflect the terrestrial environments of their drainage basins (i.e. climate, landscape geomorphology, geology, but they also display strong anthropogenic signatures. Sediment erosion increased dramatically in the last several millenia in response to deforestation, farming and mining. In the past 50 years, however, increased soil conservation and local reversion of agricultural land to forest, as well as river diversion and dam construction, have decreased the suspended sediment loads of many European rivers. Improved mining and manufacturing techniques, as well as more effective use of fertilizers and improved waste treatment, almost surely will result in lower dissolved solids and nutrient fluxes to the coastal environments, which presently are the highest in the world. The long-range effects of changed land use on estuarine and coastal environments remain to be seen, although decreased sediment loads in the past 20-40 years have already

  20. North Inlet-Winyah Bay National Estuarine Research Reserve’s (NERR) Estuarine Surface Water Nutrient, Suspended Sediment, and Chlorophyll a Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 2002-2004

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — National Estuarine Research Reserve System The National Estuarine Research Reserve System was established by the Coastal Zone Management Act of 1972 (as amended) and...

  1. Growth Characteristics of an Estuarine Heterocystous Cyanobacterium

    NARCIS (Netherlands)

    Guimarães, P.; Yunes, J.S.; Cretoiu, M.S.; Stal, L.J.

    2017-01-01

    A new estuarine filamentous heterocystous cyanobacterium was isolated from intertidal sediment of the Lagoa dos Patos estuary (Brazil). The isolate may represent a new genus related to Cylindrospermopsis. While the latter is planktonic, contains gas vesicles, and is toxic, the newly isolated strain

  2. Assessment of the climate change impacts on fecal coliform contamination in a tidal estuarine system.

    Science.gov (United States)

    Liu, Wen-Cheng; Chan, Wen-Ting

    2015-12-01

    Climate change is one of the key factors affecting the future microbiological water quality in rivers and tidal estuaries. A coupled 3D hydrodynamic and fecal coliform transport model was developed and applied to the Danshuei River estuarine system for predicting the influences of climate change on microbiological water quality. The hydrodynamic and fecal coliform model was validated using observational salinity and fecal coliform distributions. According to the analyses of the statistical error, predictions of the salinity and the fecal coliform concentration from the model simulation quantitatively agreed with the observed data. The validated model was then applied to predict the fecal coliform contamination as a result of climate change, including the change of freshwater discharge and the sea level rise. We found that the reduction of freshwater discharge under climate change scenarios resulted in an increase in the fecal coliform concentration. The sea level rise would decrease fecal coliform distributions because both the water level and the water volume increased. A reduction in freshwater discharge has a negative impact on the fecal coliform concentration, whereas a rising sea level has a positive influence on the fecal coliform contamination. An appropriate strategy for the effective microbiological management in tidal estuaries is required to reveal the persistent trends of climate in the future.

  3. NOAA's Estuarine Living Marine Resources (ELMR) Data Base

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 1985, NOAA launched the Estuarine Living Marine Resources (ELMR) Program to develop a consistent data base on the distribution, relative abundance, and life...

  4. Estuarine and offshore fishing yield statistics and fishery policies in the state of Pará

    Directory of Open Access Journals (Sweden)

    Ivan Furtado Júnior

    2006-08-01

    Full Text Available The coast of Pará State extends for 562 km and it counts on 123 artisan-fishing communities, distributed along 17 coastal municipal districts. In this area of the State, it highlights the presence of growth of mangroves, streams, rivers and estuaries. All those factors that favor the fishing productivity hinder the systematic control of the landings a lot and with consequence in obtaining fishing production statistics. This work objective is to present the statistics of fishing production for species in landing volume, in the estuarine and marine areas of Pará Estate and to analyze the fishing police for the systems of industrial and artisan production in the period from 1997 to 2003. To esteem the fishing productions of the estuarine and marine areas in Pará State. There was monthly control on the boat in activity for type of fishing gear used and accomplished samples of the landings of each one of those combinations of boat fishing gear. In the studied area, the municipal districts that concentrate the largest landings are Belém, Bragança and Vigia. The tuna and billfish captures started having some importance from 2000 in Belém City and from 2002 in Belém city and municipal district of Curuçá. The species or groups of more important species in capture volume are yellow weakfish, Thomas sea catfish, Spanish mackerel, sharks, Caribbean red snapper, king weakfish, crab, marine catfish and shrimp and, in economic, value lobsters, shrimp and Caribbean red snapper.

  5. Salt Marsh--Estuarine Ecosystem: A Liquid Asset

    Science.gov (United States)

    Steever, E. Zell

    1977-01-01

    A comprehensive description of the salt marsh-estuarine ecosystem is provided. Topics discussed include: the general geologic history and formation of this ecosystem; physical and chemical parameters; variety; primary productivity; tidal zones; kind, sizes and abundance of vegetation; and the environmental factors influencing vegetation. (BT)

  6. Development of a flow method for the determination of phosphate in estuarine and freshwaters-Comparison of flow cells in spectrophotometric sequential injection analysis

    International Nuclear Information System (INIS)

    Mesquita, Raquel B.R.; Ferreira, M. Teresa S.O.B.; Toth, Ildiko V.; Bordalo, Adriano A.; McKelvie, Ian D.; Rangel, Antonio O.S.S.

    2011-01-01

    Highlights: → Sequential injection determination of phosphate in estuarine and freshwaters. → Alternative spectrophotometric flow cells are compared. → Minimization of schlieren effect was assessed. → Proposed method can cope with wide salinity ranges. → Multi-reflective cell shows clear advantages. - Abstract: A sequential injection system with dual analytical line was developed and applied in the comparison of two different detection systems viz; a conventional spectrophotometer with a commercial flow cell, and a multi-reflective flow cell coupled with a photometric detector under the same experimental conditions. The study was based on the spectrophotometric determination of phosphate using the molybdenum-blue chemistry. The two alternative flow cells were compared in terms of their response to variation of sample salinity, susceptibility to interferences and to refractive index changes. The developed method was applied to the determination of phosphate in natural waters (estuarine, river, well and ground waters). The achieved detection limit (0.007 μM PO 4 3- ) is consistent with the requirement of the target water samples, and a wide quantification range (0.024-9.5 μM) was achieved using both detection systems.

  7. Development of a flow method for the determination of phosphate in estuarine and freshwaters-Comparison of flow cells in spectrophotometric sequential injection analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Raquel B.R. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto (Portugal); Ferreira, M. Teresa S.O.B. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Toth, Ildiko V. [REQUIMTE, Departamento de Quimica, Faculdade de Farmacia, Universidade de Porto, Rua Anibal Cunha, 164, 4050-047 Porto (Portugal); Bordalo, Adriano A. [Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Lg. Abel Salazar 2, 4099-003 Porto (Portugal); McKelvie, Ian D. [School of Chemistry, University of Melbourne, Victoria 3010 (Australia); Rangel, Antonio O.S.S., E-mail: aorangel@esb.ucp.pt [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, R. Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)

    2011-09-02

    Highlights: {yields} Sequential injection determination of phosphate in estuarine and freshwaters. {yields} Alternative spectrophotometric flow cells are compared. {yields} Minimization of schlieren effect was assessed. {yields} Proposed method can cope with wide salinity ranges. {yields} Multi-reflective cell shows clear advantages. - Abstract: A sequential injection system with dual analytical line was developed and applied in the comparison of two different detection systems viz; a conventional spectrophotometer with a commercial flow cell, and a multi-reflective flow cell coupled with a photometric detector under the same experimental conditions. The study was based on the spectrophotometric determination of phosphate using the molybdenum-blue chemistry. The two alternative flow cells were compared in terms of their response to variation of sample salinity, susceptibility to interferences and to refractive index changes. The developed method was applied to the determination of phosphate in natural waters (estuarine, river, well and ground waters). The achieved detection limit (0.007 {mu}M PO{sub 4}{sup 3-}) is consistent with the requirement of the target water samples, and a wide quantification range (0.024-9.5 {mu}M) was achieved using both detection systems.

  8. Characterization of an estuarine environment by means of an index based on intertidal macrofauna.

    Science.gov (United States)

    Conde, Anxo; Novais, Júlio M; Domínguez, Jorge

    2013-06-15

    Macrobenthic intertidal assemblages from five Atlantic Iberian estuaries were analyzed to develop an estuarine index. An R-mode analysis revealed a close association between the isopod Cyathura carinata, the polychaete Hediste diversicolor and the bivalve Scrobicularia plana. Although these species are abundant in all the estuaries considered, they tend to be absent from sites at the marine and freshwater ends of the environmental gradient. Three different ways of calculating the estuarine index are proposed. The index is comprised in the interval [0,1] and was constructed using relative abundances rather than absolute abundances. Transformation of the raw data helped improve the performance of the index. A non-parametric statistical test is proposed for application to the estuarine index to find sites with the same values after a significant omnibus test. The index appears to be a good proxy for recognizing estuarine limits by use of indicator species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Massive production of heavy metals in the Ganga (Hooghly) River estuary, India: Global importance of solute-particle interaction and enhanced metal fluxes to the oceans

    Science.gov (United States)

    Samanta, Saumik; Dalai, Tarun K.

    2018-05-01

    The Ganga River System is a major contributor to the global sediment and water discharge to the oceans. The estuary of Ganga (Hooghly) River in India is under increasing influence of anthropogenic contributions via discharge of the industrial and urban effluents. Here we document, based on the investigation of water and suspended sediment samples collected during six periods over two years, that there is extensive production of heavy metals (Co, Ni and Cu) in the estuary such that the annual dissolved fluxes of metals from the Hooghly River are enhanced by up to 230-1770%. Furthermore, the estuarine dissolved metal fluxes, when normalized with water fluxes, are the highest among estuaries of the major rivers in the world. Our simultaneous data on the dissolved, suspended particulate and exchangeable phases allow us to identify the ion-exchange process (coupled adsorption and desorption) as the dominant contributor to the generation of heavy metals in the middle and lower estuary where the estimated anthropogenic contribution is negligible. The estimated contributions from the groundwater are also insufficient to explain the measured metal concentrations in the estuary. A strong positive correlation that is observed between the dissolved heavy metal fluxes and the suspended particulate matter (SPM) fluxes, after normalizing them with the water fluxes, for estuaries of the major global rivers imply that the solute-particle interaction is a globally significant process in the estuarine production of metals. Based on this correlation that is observed for major estuaries around the world, we demonstrate that the South Asian Rivers which supply only ∼9% of the global river water discharge but carry elevated SPM load, contribute a far more significant proportion (∼40 ± 2% Ni and 15 ± 1% Cu) to the global supply of the dissolved metals from the rivers.

  10. Significance of antifouling paint flakes to the distribution of dichlorodiphenyltrichloroethanes (DDTs) in estuarine sediment

    International Nuclear Information System (INIS)

    Wu, Chen-Chou; Bao, Lian-Jun; Tao, Shu; Zeng, Eddy Y.

    2016-01-01

    Recently published literature indicated that dichlorodiphenyltrichloroethane (DDT)-containing antifouling paint flakes were heterogeneously distributed within estuarine sediments. However, the significance of antifouling paint flakes in the fate and transport of DDT compounds and other organic pollutants in estuarine sediment is yet to be adequately addressed. To fill this knowledge gap, estuarine sediment and paint flakes from cabin and boat surfaces were collected from a fishery base in Guangdong Province of South China and analyzed for DDT compounds. Coarse fractioned samples collected from the vicinity of boat maintenance facilities contained appreciable amounts of colorful particles, which were identified as paint flakes by Fourier transform infrared spectroscopy. The highest concentrations of DDXs (sum of DDTs and its metabolites) occurred in the heavy-density (>1.7 g cm"−"3) fraction of coarse-size (200–2000 μm) sediments from near the boat maintenance facilities, suggesting the importance of paint flakes in the distribution pattern of “hot spots” in estuarine sediment. Moreover, the desorption rates of DDT compounds from paint flakes and the heavy-density fraction of coarse-size sediment were both extremely slow. Apparently, unevenly distributed paint flakes in sediment can artificially inflate the sorption capacity of heavy-density sediment for DDT compounds, and therefore can substantially change the environmental fate and behavior of hydrophobic organic chemicals in estuarine sediment. Finally, commonly used source diagnostic indices of DDT compounds were mostly grain-size and density dependent in sediment, as a result of the occurrence of paint flakes, which may strongly compromise the outcome of any source diagnostics efforts. - Highlights: • Concentrations of DDTs were elevated in coarse and high-density fractions. • The desorption rates of DDTs from coarse and high-density fraction were extreme slow. • DDTs-containing antifouling

  11. Long-term study of an estuarine mudflat subjected to petro-chemical discharges

    International Nuclear Information System (INIS)

    McLusky, D.A.; Martins, T.

    1998-01-01

    The Kinneil intertidal area, situated in the middle reaches of the Forth estuary, eastern Scotland, has been subject to the effects of industrial discharges, principally from petro-chemical industries (oil refinery and chemical works) since the 1920s. The intertidal fauna has been studied annually since 1976 using consistent methodology. The study continues, now providing over 20 yrs of data. During the study period the discharges from the industrial sources have been reduced substantially through a combination of plant closure and modernization and the installation of effluent treatment works. Furthermore, the River Avon which flows across the area has experienced substantial improvements in water quality, attributed to improvements in waste treatment works at localities upstream from the estuarine site. Overall, however, the clearest trends have been increases in diversity, expressed either as mean number of species per station, or as diversity indices. These increases in diversity are shown to be a clear community response to the improvements made to the petro-chemical wastes discharged to the area. (author)

  12. ASSESSMENT OF POSSIBLE INDIRECT RISK OF NATURALLY OCCURING MERCURY AND CADMIUM THROUGH Mugil Sp. AND Geloina sp. CONSUMPTION IN SEGARA ANAKAN ESTUARINE ECOSYSTEM

    Directory of Open Access Journals (Sweden)

    Sri Noegrohati

    2010-06-01

    Full Text Available Estuarine ecosystem of Segara Anakan is located in south coast of Central Java, shielded from Indian Ocean by Nusakambangan island. The ecosystem of Segara Anakan estuary, Central Java, Indonesia, is influenced by fresh water inflow from Citanduy river basin and Indian sea water mostly by tidal actions through the western opening. The runoff materials continuously entering Segara Anakan from Citanduy catchment area, which geologically consist of weathering products of quarternary volcanic rocks from Galunggung mountain, West Java. Therefore various natural heavy metal contaminants are bound to the estuarine sediments, redistributed and accumulated within the ecosystem. In the present work, the effects of environmental stresses to mercury and cadmium abiotic distribution, and their availability to biotic ecosystems were studied, and consumers indirect risk assesment was carried out. In the laboratory scale studies on the distribution of mercury and cadmium in an estuarine simulation of water-field sediment, it was observed that the metal distribution coefficient decreases as the salinity and the acidity of the medium increases. Monitoring results confirmed that the highest levels of Hg and Cd in water and sediment samples were obtained in dry season. Consequently, the highest levels of Hg and Cd in biotic ecosystem, represented by Mugil sp. and Geloina sp., also obtained in dry season. The body burden of Hg in people of Segara Anakan villages, as indicated by the levels in hair and mother milk samples, taken at the end of the study (dry season 2004, were relatively low, but the levels of Cd in mother milk samples were significantly higher than that of control samples of Jogyakarta (P = 0.05. Consequently, the risk quotient for babies were exceeding the FAO/WHO PTWI. Based on the risk assessment carried out for babies and adults, at the present time it is advisable to consume Mugil sp. and Geloina sp., taken in wet season only and not in dry

  13. Triclosan alterations of estuarine phytoplankton community structure.

    Science.gov (United States)

    Pinckney, James L; Thompson, Laura; Hylton, Sarah

    2017-06-15

    Antimicrobial additives in pharmaceutical and personal care products are a major environmental concern due to their potential ecological impacts on aquatic ecosystems. Triclosan (TCS) has been used as an antiseptic, disinfectant, and preservative in various media. The sublethal and lethal effects of TCS on estuarine phytoplankton community composition were investigated using bioassays of natural phytoplankton communities to measure phytoplankton responses to different concentrations of TCS ranging from 1 to 200μgl -1 . The EC 50 (the concentration of an inhibitor where the growth is reduced by half) for phytoplankton groups (diatoms, chlorophytes, cryptophytes) examined in this ranged from 10.7 to 113.8μg TCS l -1 . Exposures resulted in major shifts in phytoplankton community composition at concentrations as low as 1.0μg TCS l -1 . This study demonstrates estuarine ecosystem sensitivity to TCS exposure and highlights potential alterations in phytoplankton community composition at what are typically environmental concentrations of TCS in urbanized estuaries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. SPECIES INTERACTIONS BETWEEN ESTUARINE DETRITIVORES: INHIBITION OR FACILITATION?

    Science.gov (United States)

    Native Hawaiian estuarine detritivores; the prawn Macrobrachium grandimanus, and the neritid gastropod Neritina vespertina, were maintained in flow-through microcosms with conditioned leaves from two riparian tree species, Hau (Hibiscus tiliaceus) and guava (Psidium guajava). Th...

  15. Source identification, geochemical normalization and influence factors of heavy metals in Yangtze River Estuary sediment.

    Science.gov (United States)

    Sun, Xueshi; Fan, Dejiang; Liu, Ming; Tian, Yuan; Pang, Yue; Liao, Huijie

    2018-06-18

    Sediment samples, including 40 surface samples and 12 sediment cores, were collected from 52 stations of the Yangtze River Estuary (YRE) in 2015 and 2016. The 95% linear prediction intervals (LPI) and principal components analysis (PCA), were conducted to evaluate the metal sources and grain-size effect (GSE). The in situ physico-chemical properties of pH, Eh, DO, salinity, temperature and turbidity were combined to elucidate the relationships between environmental factors and the fate of heavy metals in the river-estuary-shelf system. This study indicates a decreasing trend of metals in sediments from the estuary towards the adjacent shelf and the river channel and that Zn, Cu and Cr are mainly derived from natural processes throughout the catchment, whereas Pb appears to have anthropogenic inputs via atmospheric deposition. Furthermore, considering the best fit regression lines between the concentrations of Al and heavy metals as well as the deficiencies of the conventional C elements /C Al method, we introduce an approach (Al-SN: Al-scope normalization) that can eliminate the GSE on heavy metals and be applied to other estuaries. After Al-scope normalization, the relatively constant levels of Zn, Cu and Cr that remain in sediments from the river channel to the estuary and shelf confirmed that the variation of grain size in sediments almost entirely explained the distribution patterns of sediment toxicity in the YRE, while the enrichment of Pb in estuarine sediments could be attributed to its chemical species and physico-chemical properties. The results further suggest that the relationship between grain size and spatial behavior of sediment pollutants should be given priority over the contamination assessment and provenance discrimination in estuarine or similar environments with complex sediment compositions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Fish community-based measures of estuarine ecological quality and pressure-impact relationships

    Science.gov (United States)

    Fonseca, Vanessa F.; Vasconcelos, Rita P.; Gamito, Rita; Pasquaud, Stéphanie; Gonçalves, Catarina I.; Costa, José L.; Costa, Maria J.; Cabral, Henrique N.

    2013-12-01

    Community-based responses of fish fauna to anthropogenic pressures have been extensively used to assess the ecological quality of estuarine ecosystems. Several methodologies have been developed recently combining metrics reflecting community structure and function. A fish community facing significant environmental disturbances will be characterized by a simplified structure, with lower diversity and complexity. However, estuaries are naturally dynamic ecosystems exposed to numerous human pressures, making it difficult to distinguish between natural and anthropogenic-induced changes to the biological community. In the present work, the variability of several fish metrics was assessed in relation to different pressures in estuarine sites. The response of a multimetric index (Estuarine Fish Assessment Index) was also analysed. Overall, fish metrics and the multimetric index signalled anthropogenic stress, particularly environmental chemical pollution. The fish assemblage associated with this type of pressure was characterized by lower species diversity, lower number of functional guilds, lower abundance of marine migrants and of piscivorous individuals, and higher abundance of estuarine resident species. A decreased ecological quality status, based on the EFAI, was also determined for sites associated with this pressure group. Ultimately, the definition of each pressure groups favoured a stressor-specific analysis, evidencing pressure patterns and accounting for multiple factors in a highly dynamic environment.

  17. Progress and challenges in coupled hydrodynamic-ecological estuarine modeling

    Science.gov (United States)

    Ganju, Neil K.; Brush, Mark J.; Rashleigh, Brenda; Aretxabaleta, Alfredo L.; del Barrio, Pilar; Grear, Jason S.; Harris, Lora A.; Lake, Samuel J.; McCardell, Grant; O'Donnell, James; Ralston, David K.; Signell, Richard P.; Testa, Jeremy; Vaudrey, Jamie M. P.

    2016-01-01

    Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review, we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a “theory of everything” for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.

  18. Foraminifera and Thecamoebians as hydrodynamic indicators for Amazon estuarine system

    Science.gov (United States)

    Laut, L. L.; Figueiredo, A. G.; Santos, V. F.; Souza-Vieira, S.

    2007-05-01

    The Amazon mangrove forest in Brazilian territory is one of the most extended in the world. It goes from Ponta do Tubarao (4S e 43W) to Cape Orange (5N e 51W) along 2,250 km of coast line. Because the Amazon River System influence, it can be divided into two regions; one with river influence toward north and the other without river influence. In order to characterize the mangrove environment hydrodynamic on both sides of the Amazon River System, foraminifera and thecamoebians assemblages were investigated in the sediment of two estuaries; Araguari to the North (1 15S - 50 30W) and Caete to the South (0 50S - 46 30W). For both estuaries forams and thecamoebians species distribution are atypical relative to other world regions. In both, there are only few calcareous forams and almost all are small and possible of being transported in suspension. Typical estuarine species were not identified. The typical mangrove forams which are agglutinated species were dominant in both estuaries. However, the Caete estuary has a large number of forams species (29), indicating better efficiency in mixing fresh and salt water in comparison to the Araguari. On the other hand, the Araguari has big richness of thecamoebians species (15) indicating fresh water prevalence. The fresh water predominance is due to the Amazon water plume being diverted to the Amapa coast where the Araguari estuary is located. The foraminifera species was also used to determine the salt water penetration in the estuary. In the Caete estuary, salt water penetrates to about 40 km while in the Araguari it does coincide with the limit of the bore tide wave "pororoca" penetration, 45 km. Based on the species succession (forams to thecamoebians species) the Araguary estuary can be divided into three regions controlled by turbidity: the outer, middle and inner estuary. The Caete species succession is not that clear and only could be divided based on salinity into outer and inner estuary. In both estuaries forams and

  19. Assessing estuarine biota in southern California

    Science.gov (United States)

    Kevin D. Lafferty

    2005-01-01

    In southern California, most estuarine wetlands are gone, and what little habitat remains is degraded. For this reason, it is often of interest to assess the condition of estuaries over time, such as when determining the success of a restoration project. To identify impacts or opportunities for restoration, we also may want to know how a particular estuary, or area...

  20. Shrimp farming in estuarine environment: Points to ponder

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.

    of the expansion has taken place around the estuarine area as it facilitates water exchange and waste disposal. In semi-intensive and extensive type of farming practices, use of different types of chemicals and antibiotics, artificial feeds, probiotics...

  1. Behavior of 226Ra in the Mississippi River mixing zone

    Science.gov (United States)

    Moore, Daniel G.; Scott, Martha R.

    1986-12-01

    The behavior of 226Ra in the Mississippi River mixing zone is strongly nonconservative and includes desorption similar to that reported for the Hudson, Pee Dee, and Amazon rivers. However, dissolved and desorbed 226Ra concentrations in the Mississippi are 2 to 5 times greater than in the other rivers at the same salinity. Radium concentrations vary inversely with the water discharge rate. The 226Ra desorption maximum occurs at a salinity of 5.0, much lower than the 18 to 28 salinity values for the maxima of the other three rivers. High concentrations of dissolved 226Ra (up to 82 dpm per 100 L) and the low salinity values for the desorption maximum in the Mississippi River result from three major factors. Suspended sediments include a large fraction of montmorillonite, which gives the sediment a high cation exchange capacity, 0.54 meq/g. The average suspended sediment load is large, about 510 mg/L, and contains 1.9 dpm/g desorbable 226Ra. The dissolved 226Ra river water end-member (9.6 dpm per 100 L) is higher than in surface seawater. The annual contribution of 226Ra to the ocean from the Mississippi River is 3.7 × 1014 dpm/yr, based on data from three cruises. Evidence of flux of 226Ra from estuarine and shelf sediments is common in vertical profile sampling of the deltaic waters but is not reflected in calculations made with an "apparent" river water Ra value extrapolated to zero salinity.

  2. Assessing estuarine quality: A cost-effective in situ assay with amphipods.

    Science.gov (United States)

    Martinez-Haro, Monica; Acevedo, Pelayo; Pais-Costa, Antónia Juliana; Taggart, Mark A; Martins, Irene; Ribeiro, Rui; Marques, João Carlos

    2016-05-01

    In situ assays based on feeding depression can be powerful ecotoxicological tools that can link physiological organism-level responses to population and/or community-level effects. Amphipods are traditional target species for toxicity tests due to their high sensitivity to contaminants, availability in the field and ease of handling. However, cost-effective in situ assays based on feeding depression are not yet available for amphipods that inhabit estuarine ecosystems. The aim of this work was to assess a short-term in situ assay based on postexposure feeding rates on easily quantifiable food items with an estuarine amphipod. Experiments were carried out under laboratory conditions using juvenile Echinogammarus marinus as the target individual. When 60 Artemia franciscana nauplii (as prey) were provided per individual for a period of 30 min in dark conditions, feeding rates could be easily quantified. As an endpoint, postexposure feeding inhibition in E. marinus was more sensitive to cadmium contamination than mortality. Assay calibration under field conditions demonstrated the relevance of sediment particle size in explaining individual feeding rates in uncontaminated water bodies. An evaluation of the 48-h in situ bioassay based on postexposure feeding rates indicated that it is able to discriminate between unpolluted and polluted estuarine sites. Using the harmonized protocol described here, the in situ postexposure feeding assay with E. marinus was found to be a potentially useful, cost-effective tool for assessing estuarine sediment and water quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. The capability of estuarine sediments to remove nitrogen: implications for drinking water resource in Yangtze Estuary.

    Science.gov (United States)

    Liu, Lin; Wang, Dongqi; Deng, Huanguang; Li, Yangjie; Chang, Siqi; Wu, Zhanlei; Yu, Lin; Hu, Yujie; Yu, Zhongjie; Chen, Zhenlou

    2014-09-01

    Water in the Yangtze Estuary is fresh most of the year because of the large discharge of Yangtze River. The Qingcaosha Reservoir built on the Changxing Island in the Yangtze Estuary is an estuarine reservoir for drinking water. Denitrification rate in the top 10 cm sediment of the intertidal marshes and bare mudflat of Yangtze Estuarine islands was measured by the acetylene inhibition method. Annual denitrification rate in the top 10 cm of sediment was 23.1 μmol m(-2) h(-1) in marshes (ranged from 7.5 to 42.1 μmol m(-2) h(-1)) and 15.1 μmol m(-2) h(-1) at the mudflat (ranged from 6.6 to 26.5 μmol m(-2) h(-1)). Annual average denitrification rate is higher at mashes than at mudflat, but without a significant difference (p = 0.084, paired t test.). Taking into account the vegetation and water area of the reservoir, a total 1.42 × 10(8) g N could be converted into nitrogen gas (N2) annually by the sediment, which is 97.7 % of the dissolved inorganic nitrogen input through precipitation. Denitrification in reservoir sediment can control the bioavailable nitrogen level of the water body. At the Yangtze estuary, denitrification primarily took place in the top 4 cm of sediment, and there was no significant spatial or temporal variation of denitrification during the year at the marshes and mudflat, which led to no single factor determining the denitrification process but the combined effects of the environmental factors, hydrologic condition, and wetland vegetation.

  4. 75 FR 65613 - National Estuarine Research Reserve System

    Science.gov (United States)

    2010-10-26

    ... based on priority issues defined by the reserve. The objectives described in this plan are designed to... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research..., National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce...

  5. Defense Coastal/Estuarine Research Program (DCERP)

    Science.gov (United States)

    2007-09-19

    activities, splash points and Landing Craft Air Cushion (LCAC) operations) and non-military Base activities (e.g., sewage treatment , storm water runoff and...We will measure the metabolism of benthic microalgae, the water column, eelgrass, and any dominant macroalgae by developing series of photosynthesis...activities (storm water control and sewage treatment ). Defense Coastal/Estuarine Research Program (DCERP) Research Plan DCERP Research Plan 32 September 19

  6. Estuarine Oceanography. CEGS Programs Publication Number 18.

    Science.gov (United States)

    Wright, F. F.

    Estuarine Oceanography is one in a series of single-topic problem modules intended for use in undergraduate and earth science courses. Designed for those interested in coastal oceanography or limnology, the module is structured as a laboratory supplement for undergraduate college classes but should be useful at all levels. The module has two…

  7. Manganese and iron as oxygen carriers to anoxie estuarine sediment

    Science.gov (United States)

    Brayner, F. M. M.; Matvienko, B.

    2003-05-01

    We studied the concentration of a series of transition metals including Mn and Fe in an estuarine fishpond. The pond is situated at latitude 8°10'S and longitude 34°55'W, in the Capibaribe River estuary, within the Recife city boundaries, which is located in Pernambuco, a state of the Brazilian Northeast Pond area is 1.5 ha and it bas a 0.5 m depth. It is separated from the river by dikes. Water temperature at 28° C is stable throughout the year. Light breezes keep the water aerated, but intense ongoing decomposition makes the sediment anoxie. The area, originally of mangrove type, has been changed by antropic action on its fauna and vegetation. The study focuses on changes in behaviour of heavy metals. Samples of bottom sediments wore collected by Eckman dredge sediment sampler and total metal concentration was determined by the lithium borate fusion method. Water, recent sediment, and consolidated sediment were examined in this fishpond where Mn and Fe are brought in periodically by water and then gradually go into the sediment at respective rates of 10.52 and 1332 mg m^{-2}a^{-1}. Strong bioturbation re-suspends sediment while simultaneously re-dissolution of these ions is going on fhrough reduction in the anoxie sédiment. As soluble species these ions migrate from sediment to water and are there continually oxidized by dissolved oxygen, becoming insoluble. With their precipitation, chemically bound oxygen is carried down to the sediment, constituting a parallel channel of transport in addition to migration into the sediment bydiffusion of the oxygen dissolved in the water. The estimated flow rates are 3.25 and 76 mg O2 m^{-2}a^{-1} due to Mn and Fe respectively. The rates were established using natural silicon as a tracer.

  8. Land use, land cover, and drainage on the Albemarle-Pamlico Peninsula, Eastern North Carolina, 1974

    Science.gov (United States)

    Daniel, C.C.

    1978-01-01

    A land use, land cover, and drainage map of the 2,000-square-mile Albermarle-Pamlico peninsula of eastern North Carolina has been prepared, at a scale of 1:125,000, as part of a larger study of the effects of large-scale land clearing on regional hydrology. The peninsula includes the most extensive area of wetland in North Carolina and one of the largest in the country. In recent years the pace of land clearing on the peninsula has accelerated as land is being converted from forest, swamp, and brushland to agricultural use. Conversion of swamps to intensive farming operations requires profound changes in the landscape. Vegetation is uprooted and burned and ditches and canals are dug to remove excess water. What is the impact of these changes on ground-water supplies and on the streams and surrounding coastal waters which receive the runoff This map will aid in answering these and similar questions that have arisen about the patterns of land use and the artificial drainage system that removes excess water from the land. By showing both land use and drainage, this map can be used to identify those areas where water-related problems may occur and help assess the nature and causes of these problems. The map covers the entire area east of the Suffolk Scarp, an area of about 2,000 square miles, for the year 1974 using data from 1974-76. Land use and land cover were compiled and modified from the U.S. Geological Survey 's Rocky Mount and Manteo LUDA maps. Additional information came from U.S. Geological Survey orthophotoquads, Landsat imagery, and field checking. Drainage was mapped from orthophotoquads, some field inspection, and 7-1/2 minute topographic quadrangle maps.

  9. 76 FR 40338 - National Estuarine Research Reserve System

    Science.gov (United States)

    2011-07-08

    ... coastal issues of the reserve related to water quality (non-point source pollution), invasive species... Reserve System AGENCY: Estuarine Reserves Division, Office of Ocean and Coastal Resource Management.... ACTION: Notice of Approval and Availability for Revised Management Plans for ACE Basin, SC National...

  10. Does biodiversity of estuarine phytoplankton depend on hydrology?

    NARCIS (Netherlands)

    Ferreira, JG; Wolff, WJ; Simas, TC; Bricker, SB

    2005-01-01

    Phytoplankton growth in estuaries is controlled by factors such as flushing, salinity tolerance, light, nutrients and grazing. Here, we show that biodiversity of estuarine phytoplankton is related to flushing, and illustrate this for some European estuaries. The implications for the definition of

  11. Biogeochemical transport in the Loxahatchee River estuary, FL: The role of submarine groundwater discharge

    Science.gov (United States)

    Swarzenski, P.; Orem, B.; McPherson, B.; Baskaran, M.; Wan, Y.

    2005-05-01

    The distributions of dissolved organic carbon (DOC), silica, select trace elements (Mn, Fe, Ba, Sr, Co, V,) and a suite of naturally-occurring radionuclides in the U/Th decay series (222Rn, 223,224,226,228Ra, 238U) were studied during high and low discharge conditions in the Loxahatchee River estuary, Florida. The zero-salinity endmember of this still relatively pristine estuary may reflect not only river-borne constituents, but also those advected during active groundwater/surface-water discharge. During low discharge conditions, with the notable exception of Co, trace metals indicate nearly conservative mixing from a salinity of ~12 through the estuary (This statement contracdicts with what is said in p. 7). In contrast, of the trace metals studied, only Sr, Fe, U and V exhibited conservative estuarine mixing during high discharge. Dissolved organic carbon and Si concentrations were highest at zero salinities, and generally decreased with an increase in salinity during both discharge regimes, indicating removal of land-derived dissolved organic matter and silica in the estuary. Suspended particulate matter (SPM) concentrations were generally lowest ( 28 dpm L-1) at the freshwater endmember of the estuary, and appear to identify regions of the river most influenced by active submarine groundwater discharge (where is the data that show this?). Activities of four naturally-occurring isotopes of Ra (223,224,226,228Ra) in this estuary and select adjacent shallow groundwater wells indicate mean estuarine water mass residence times of less than 1 day; values in close agreement to those calculated by tidal prism and tidal period. A radium-based model for estimating submarine groundwater discharge to the Loxahatchee River estuary yielded an average of 1.03 V 3.84 x 105 m3 day-1, depending on river discharge stage as well as slight variations in the particular Ra models used. Such calculated flux estimates are in close agreement with results obtained from a 2-day

  12. Impacts of flocculation on the distribution and diagenesis of iron in boreal estuarine sediments

    Directory of Open Access Journals (Sweden)

    T. Jilbert

    2018-03-01

    Full Text Available Iron (Fe plays a key role in sedimentary diagenetic processes in coastal systems, participating in various redox reactions and influencing the burial of organic carbon. Large amounts of Fe enter the marine environment from boreal river catchments associated with dissolved organic matter (DOM and as colloidal Fe oxyhydroxides, principally ferrihydrite. However, the fate of this Fe pool in estuarine sediments has not been extensively studied. Here we show that flocculation processes along a salinity gradient in an estuary of the northern Baltic Sea efficiently transfer Fe and OM from the dissolved phase into particulate material that accumulates in the sediments. Flocculation of Fe and OM is partially decoupled. This is likely due to the presence of discrete colloidal ferrihydrite in the freshwater Fe pool, which responds differently from DOM to estuarine mixing. Further decoupling of Fe from OM occurs during sedimentation. While we observe a clear decline with distance offshore in the proportion of terrestrial material in the sedimentary particulate organic matter (POM pool, the distribution of flocculated Fe in sediments is modulated by focusing effects. Labile Fe phases are most abundant at a deep site in the inner basin of the estuary, consistent with input from flocculation and subsequent focusing. The majority of the labile Fe pool is present as Fe (II, including both acid-volatile sulfur (AVS-bound Fe and unsulfidized phases. The ubiquitous presence of unsulfidized Fe (II throughout the sediment column suggests Fe (II-OM complexes derived from reduction of flocculated Fe (III-OM, while other Fe (II phases are likely derived from the reduction of flocculated ferrihydrite. Depth-integrated rates of Fe (II accumulation (AVS-Fe + unsulfidized Fe (II + pyrite for the period 1970–2015 are greater in the inner basin of the estuary with respect to a site further offshore, confirming higher rates of Fe reduction in near-shore areas

  13. Impacts of flocculation on the distribution and diagenesis of iron in boreal estuarine sediments

    Science.gov (United States)

    Jilbert, Tom; Asmala, Eero; Schröder, Christian; Tiihonen, Rosa; Myllykangas, Jukka-Pekka; Virtasalo, Joonas J.; Kotilainen, Aarno; Peltola, Pasi; Ekholm, Päivi; Hietanen, Susanna

    2018-03-01

    Iron (Fe) plays a key role in sedimentary diagenetic processes in coastal systems, participating in various redox reactions and influencing the burial of organic carbon. Large amounts of Fe enter the marine environment from boreal river catchments associated with dissolved organic matter (DOM) and as colloidal Fe oxyhydroxides, principally ferrihydrite. However, the fate of this Fe pool in estuarine sediments has not been extensively studied. Here we show that flocculation processes along a salinity gradient in an estuary of the northern Baltic Sea efficiently transfer Fe and OM from the dissolved phase into particulate material that accumulates in the sediments. Flocculation of Fe and OM is partially decoupled. This is likely due to the presence of discrete colloidal ferrihydrite in the freshwater Fe pool, which responds differently from DOM to estuarine mixing. Further decoupling of Fe from OM occurs during sedimentation. While we observe a clear decline with distance offshore in the proportion of terrestrial material in the sedimentary particulate organic matter (POM) pool, the distribution of flocculated Fe in sediments is modulated by focusing effects. Labile Fe phases are most abundant at a deep site in the inner basin of the estuary, consistent with input from flocculation and subsequent focusing. The majority of the labile Fe pool is present as Fe (II), including both acid-volatile sulfur (AVS)-bound Fe and unsulfidized phases. The ubiquitous presence of unsulfidized Fe (II) throughout the sediment column suggests Fe (II)-OM complexes derived from reduction of flocculated Fe (III)-OM, while other Fe (II) phases are likely derived from the reduction of flocculated ferrihydrite. Depth-integrated rates of Fe (II) accumulation (AVS-Fe + unsulfidized Fe (II) + pyrite) for the period 1970-2015 are greater in the inner basin of the estuary with respect to a site further offshore, confirming higher rates of Fe reduction in near-shore areas. Mössbauer 57Fe

  14. Tide-Dominated Tract (TDT) as a key sedimentary zone characterizing tide-dominated large-river delta and estuary systems

    Science.gov (United States)

    Saito, Y.

    2017-12-01

    sediments (inclusive of tidal thythmite), distributed over 200 km in the valley, inside of the paleo-shoreline. Similarly, such well-preserved sediments are formed in a TDT of a large-river transgressive estuarine system. An estuarine facies model for large-river systems is the need of the hour. cf. references Gugliotta et al., Process regime, salinity, morphological, and sedimentary trends along the fluvial to marine transition zone of the mixed-energy Mekong River delta, Vietnam. Continental Shelf Research. http://dx.doi.org/10.1016/j.csr.2017.03.001. Hori et al., 2001. Sedimentary facies of the tide-dominated paleo-Changjiang (Yangtze) estuary during the last transgression. Marine Geology, 177, 331-351.

  15. 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).

  16. 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)

  17. Multi-elemental contamination and historic record in sediments from the Santos-Cubatao Estuarine System, Brazil

    International Nuclear Information System (INIS)

    Luiz-Silva, Wanilson; Machado, Wilson; Matos, Rosa H.R.

    2008-01-01

    This paper records for the first time the contamination history and identifies the sources of 38 elements in sediments from the Santos-Cubatao Estuarine System (SE Brazil), at one of the most industrialized areas in Latin America. The compositions of samples from a 260 cm long sediment core collected in the Morrao River estuary were determined by ICP-MS. Enrichment factors, principal component analysis, correlation matrixes, and the characterization of geochemical signatures permitted a consistent data evaluation. Contaminant elements such as Cr, Mn, Ni, Zn, Ga, Ag, Cd, Sn, Sb, Pb, and Bi were associated with steel plant-derived Fe concentrations, while Be, Ca, Sc, Co, Cu, Sr, Y, Zr, Nb, Hf, Ta, Th, and U were associated with fertilizer industry-derived P concentrations. An overlap of sedimentary Fe distribution and local steel plant production indicated that Fe is a reliable marker of the contamination history, allowing the estimation of sedimentation rates over a period of 45 years of industrial activities. (author)

  18. Ecology of Vibrio vulnificus in estuarine waters of eastern North Carolina.

    Science.gov (United States)

    Pfeffer, Courtney S; Hite, M Frances; Oliver, James D

    2003-06-01

    While several studies on the ecology of Vibrio vulnificus in Gulf Coast environments have been reported, there is little information on the distribution of this pathogen in East Coast waters. Thus, we conducted a multiyear study on the ecology of V. vulnificus in estuarine waters of the eastern United States, employing extensive multiple regression analyses to reveal the major environmental factors controlling the presence of this pathogen, and of Vibrio spp., in these environments. Monthly field samplings were conducted between July 2000 and April 2002 at six different estuarine sites along the eastern coast of North Carolina. At each site, water samples were taken and nine physicochemical parameters were measured. V. vulnificus isolates, along with estuarine bacteria, Vibrio spp., Escherichia coli organisms, and total coliforms, were enumerated in samples from each site by using selective media. During the last 6 months of the study, sediment samples were also analyzed for the presence of vibrios, including V. vulnificus. Isolates were confirmed as V. vulnificus by using hemolysin gene PCR or colony hybridization. V. vulnificus was isolated only when water temperatures were between 15 and 27 degrees C, and its presence correlated with water temperature and dissolved oxygen and vibrio levels. Levels of V. vulnificus in sediments were low, and no evidence for an overwintering in this environment was found. Multiple regression analysis indicated that vibrio levels were controlled primarily by temperature, turbidity, and levels of dissolved oxygen, estuarine bacteria, and coliforms. Water temperature accounted for most of the variability in the concentrations of both V. vulnificus (47%) and Vibrio spp. (48%).

  19. Managing bay and estuarine ecosystems for multiple services

    Science.gov (United States)

    Needles, Lisa A.; Lester, Sarah E.; Ambrose, Richard; Andren, Anders; Beyeler, Marc; Connor, Michael S.; Eckman, James E.; Costa-Pierce, Barry A.; Gaines, Steven D.; Lafferty, Kevin D.; Lenihan, Junter S.; Parrish, Julia; Peterson, Mark S.; Scaroni, Amy E.; Weis, Judith S.; Wendt, Dean E.

    2013-01-01

    Managers are moving from a model of managing individual sectors, human activities, or ecosystem services to an ecosystem-based management (EBM) approach which attempts to balance the range of services provided by ecosystems. Applying EBM is often difficult due to inherent tradeoffs in managing for different services. This challenge particularly holds for estuarine systems, which have been heavily altered in most regions and are often subject to intense management interventions. Estuarine managers can often choose among a range of management tactics to enhance a particular service; although some management actions will result in strong tradeoffs, others may enhance multiple services simultaneously. Management of estuarine ecosystems could be improved by distinguishing between optimal management actions for enhancing multiple services and those that have severe tradeoffs. This requires a framework that evaluates tradeoff scenarios and identifies management actions likely to benefit multiple services. We created a management action-services matrix as a first step towards assessing tradeoffs and providing managers with a decision support tool. We found that management actions that restored or enhanced natural vegetation (e.g., salt marsh and mangroves) and some shellfish (particularly oysters and oyster reef habitat) benefited multiple services. In contrast, management actions such as desalination, salt pond creation, sand mining, and large container shipping had large net negative effects on several of the other services considered in the matrix. Our framework provides resource managers a simple way to inform EBM decisions and can also be used as a first step in more sophisticated approaches that model service delivery.

  20. Sup(239,240)Pu in estuarine and shelf waters of the north-eastern United States

    International Nuclear Information System (INIS)

    Sholkovitz, E.R.; Mann, D.R.

    1987-01-01

    The distribution of sup(239,240)Pu between dissolved and particulate forms has been measured in four estuaries on the north-east coast of the United States (Connecticut River, Delaware Bay, Chesapeake Bay, and Mullica River). The data cover the whole salinity range from freshwater input to shelf waters at 3.5% and includes one profile from a nearly anoxic basin in the Chesapeake Bay. In the organic-rich Mullica River estuary, large-scale removal of riverine dissolved sup(239,240)Pu occurs at low salinities due to salt-induced coagulation, a mechanism analogous to that for iron and humic acids. Within the 0 to 2.5-3.5% zone in the other three estuaries, the activity of dissolved sup(239,240)Pu increases almost conservatively. The activities of particulate sup(239,240)Pu are highest in the more turbid waters of low salinity regime (0-1.5%), but become increasingly insignificant with respect to dissolved sup(239,240)Pu as salinities increase. At higher salinities corresponding to shelf water, there is a sharp increase in dissolved sup(239,240)Pu activity. The dissolved sup(239,240)Pu activity within each estuary appears to be inversely related to the flushing time of water. The sharp decrease in dissolved sup(239,240)Pu activities between shelf and estuarine waters appears to be driven by removal within the estuaries themselves rather than on the shelf. Dissolved sup(239,240)Pu activities are lower in the nearly-anoxic bottom waters of Chesapeake Bay indicating enhanced removal by redox transformation of Pu [i.e., Pu(V) to Pu(IV)]. (author)

  1. Benthic foraminiferal biocoenoses in the estuarine regimes of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.

    Benthic Foraminifera are highly responsive to subtle changes in the estuarine environment. Keeping this in view, a qualitative analysis of living benthic Foraminifera was made of the samples collected from the Mandovi-Zuari estuaries...

  2. Role of Phragmites australis (common reed) for heavy metals phytoremediation of estuarine sediments.

    Science.gov (United States)

    Cicero-Fernández, Diego; Peña-Fernández, Manuel; Expósito-Camargo, Jose A; Antizar-Ladislao, Blanca

    2016-01-01

    The ability of Phragmites australis to take up heavy metals (Co, Ni, Mo, Cd, Pb, Cr, Cu, Fe, Mn, Zn, and Hg) and other trace elements (As, Se, Ba), from estuarine sediments was investigated using a pilot plant experimental approach. Bioaccumulation (BCF) and translocation factors (TF) were calculated in vegetative and senescence periods for two populations of P. australis, from contaminated (MIC) and non-contaminated (GAL) estuarine sediments, respectively, both growing in estuarine contaminated sediment (RIA) from ría del Carmen y Boo, Santander Bay, Spain. The highest BCF values were obtained for Ni (0.43), Ba (0.43) Mo (0.36), Cr (0.35), and Cd (0.31) for plants collected from site GAL following the senescence period. The highest BCF values recorded for plants collected from MIC following the senescence period were for Mo (0.22) and Cu (0.22). Following senescence, plants collected from GAL and MIC presented TF>1 for Ni, Mo, Se, and Zn, and in addition plants collected from MIC presented TF>1 for Ba, Cr, and Mn. A substantial increase of Micedo's rhizosphere, six times higher than Galizano's rhizosphere, suggested adaptation to contaminated sediment. The evaluated communities of P. australis demonstrated their suitability for phytoremediation of heavy metals contaminated estuarine sediments.

  3. Spatial and seasonal variability of trace-element concentrations in sediments from the Santos-Cubatao estuarine system, Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Luiz-Silva, Wanilson; Matos, Rosa Helena Ribeiro; Kristosch, Giane Chaves; Machado, Wilson

    2006-01-01

    Multi-element analyses of sediment samples from the Santos-Cubatao Estuarine System were carried out to investigate the spatial and seasonal variability of trace-element concentrations. The study area contains a rich mangrove ecosystem that is a habitat for tens of thousands of resident and migratory birds, some of them endangered globally. Enrichments of metals in fine-grained surface sediments are, in decreasing order, Hg, Mn, La, Ca, Sr, Cd, Zn, Pb, Ba, Cu, Cr, Fe, Nb, Y, Ni and Ga, relative to pre-industrial background levels. The maximum enrichment ranged from 49 (Hg) to 3.1 (Ga). Mercury concentrations were greater in the Cubatao river than in other sites, while the other elements showed greater concentrations in the Morrao river. Concentrations of Mn were significantly greater in winter and autumn than in summer and spring. However, other elements (e.g. Cd and Pb) showed the opposite, with greater concentrations in summer and spring. This study suggests that seasonal changes in physical and chemical conditions may affect the degree of sediment enrichment and therefore make the assessment of contamination difficult. Consequently, these processes need to be considered when assessing water quality and the potential contamination of biota.(author)

  4. Control of fouling organisms in estuarine cooling water systems by chlorine and bromine chloride

    International Nuclear Information System (INIS)

    Burton, D.T.; Margrey, S.L.

    1979-01-01

    The study described was initiated to evaluate the antifouling effectiveness of chlorine and bromine chloride in low velocity flow areas where estuarine waters are used for cooling purposes. The relative antifouling effectiveness of chlorine and bromine chloride under intermittent and continuous modes of application in low velocity flow areas was evaluated at an estuarine power plant located on the Chesapeake Bay

  5. Dissolved Vanillin as Tracer for Estuarine Lignin Conversion

    Science.gov (United States)

    Edelkraut, F.

    1996-12-01

    Lignin is produced only by vascular plants and therefore can be used as a tracer for terrestrial organic carbon input to the estuarine and marine environments. Lignin measurements have been done by analyses of the oxidation products such as vanillin or 4-hydroxybenzaldehyde. In the Elbe Estuary, free dissolved vanillin was analysed in order to test whether such measurements yield information on terrestrial carbon inputs into the Estuary and on the vanillin derived from lignin oxidation. In the period 1990-1992, concentrations of dissolved vanillin in the Elbe ranged from 0 to 60 μ g l -1(mean: 8 μg l -1). Higher values were found in areas of increased microbial activity such as the turbidity zone and the river mouth where the water chemistry is influenced by large tidal flats. No correlation was found between dissolved vanillin and suspended matter concentrations, although lignin is normally associated with suspended particulate matter, nor was a covariance seen between dissolved vanillin and the terrestrial carbon inputs into the Estuary. Apparently, biological conversion of lignin was faster than the transport processes, and local sources were more dominant for the vanillin concentration than riverine sources. The dissolved vanillin turnover was fast and, consequently, a significant amount of lignin may be converted within an estuary. In sediments from the Estuary, the concentrations of dissolved vanillin were similar to those found in the water phase and showed no clear vertical profile. The sediment is unlikely to be the source for vanillin.

  6. Macrophytes in estuarine gradients : Flow through flexible vegetation

    NARCIS (Netherlands)

    Dijkstra, J.T.

    2012-01-01

    Aquatic plants –or macrophytes- are an important part of coastal, estuarine and freshwater ecosystems worldwide, both from an ecological and an engineering viewpoint. Their meadows provide a wide range of ecosystem services: forming a physical protection of the shoreline, enhancing water quality and

  7. DCERP Defense Coastal/Estuarine Research Program Workshop Proceedings

    Science.gov (United States)

    2005-02-01

    regions (including submerged aquatic vegetation, macroalgae and microalgae) • Estuarine and riverine water column • Beach and dunes • Surf zone...following the activation of the new water treatment plant. Assess upstream and tributary contaminant contributions resulting in eutrophication problems...12 3.2 WATER QUALITY

  8. Methodology for impact assessment in the estuarine/marine environment

    International Nuclear Information System (INIS)

    Haven, K.F.

    1975-01-01

    Impacts on the estuarine/marine environment can be assessed in economic terms by tracing the impact flow out of the economic sector through the marine environment and back into the economic sector as changes in natural resource availability. An impact can then be measured by the changes created in the economic sector by changes in resource availability. Primary emphasis is placed on the development of an appropriate ecological model of the estuarine environment for this purpose. Two types, an ecological input/output model and a dynamic (difference equation) model, are proposed. Acceptability criteria for these models include the ability to track lethal and sublethal, direct and indirect (food web), and short- and long-term effects of a variety of pollutants related to the production and use of various energy resources

  9. Estuarine turbidity, flushing, salinity, and circulation

    Science.gov (United States)

    Pritchard, D. W.

    1972-01-01

    The effects of estuarine turbidity, flushing, salinity, and circulation on the ecology of the Chesapeake Bay are discussed. The sources of fresh water, the variations in salinity, and the circulation patterns created by temperature and salinity changes are analyzed. The application of remote sensors for long term observation of water temperatures is described. The sources of sediment and the biological effects resulting from increased sediments and siltation are identified.

  10. Hyperspectral signatures and WorldView-3 imagery of Indian River Lagoon and Banana River Estuarine water and bottom types

    Science.gov (United States)

    Bostater, Charles R.; Oney, Taylor S.; Rotkiske, Tyler; Aziz, Samin; Morrisette, Charles; Callahan, Kelby; Mcallister, Devin

    2017-10-01

    Hyperspectral signatures and imagery collected during the spring and summer of 2017 and 2016 are presented. Ground sampling distances (GSD) and pixel sizes were sampled from just over a meter to less than 4.0 mm. A pushbroom hyperspectral imager was used to calculate bidirectional reflectance factor (BRF) signatures. Hyperspectral signatures of different water types and bottom habitats such as submerged seagrasses, drift algae and algal bloom waters were scanned using a high spectral and digital resolution solid state spectrograph. WorldView-3 satellite imagery with minimal water wave sun glint effects was used to demonstrate the ability to detect bottom features using a derivative reflectance spectroscopy approach with the 1.3 m GSD multispectral satellite channels centered at the solar induced fluorescence band. The hyperspectral remote sensing data collected from the Banana River and Indian River Lagoon watersheds represents previously unknown signatures to be used in satellite and airborne remote sensing of water in turbid waters along the US Atlantic Ocean coastal region and the Florida littoral zone.

  11. Cross-Scale Baroclinic Simulation of the Effect of Channel Dredging in an Estuarine Setting

    Directory of Open Access Journals (Sweden)

    Fei Ye

    2018-02-01

    Full Text Available Holistic simulation approaches are often required to assess human impacts on a river-estuary-coastal system, due to the intrinsically linked processes of contrasting spatial scales. In this paper, a Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM is applied in quantifying the impact of a proposed hydraulic engineering project on the estuarine hydrodynamics. The project involves channel dredging and land expansion that traverse several spatial scales on an ocean-estuary-river-tributary axis. SCHISM is suitable for this undertaking due to its flexible horizontal and vertical grid design and, more importantly, its efficient high-order implicit schemes applied in both the momentum and transport calculations. These techniques and their advantages are briefly described along with the model setup. The model features a mixed horizontal grid with quadrangles following the shipping channels and triangles resolving complex geometries elsewhere. The grid resolution ranges from ~6.3 km in the coastal ocean to 15 m in the project area. Even with this kind of extreme scale contrast, the baroclinic model still runs stably and accurately at a time step of 2 min, courtesy of the implicit schemes. We highlight that the implicit transport solver alone reduces the total computational cost by 82%, as compared to its explicit counterpart. The base model is shown to be well calibrated, then it is applied in simulating the proposed project scenario. The project-induced modifications on salinity intrusion, gravitational circulation, and transient events are quantified and analyzed.

  12. Dating sediment cores from Hudson River marshes

    International Nuclear Information System (INIS)

    Robideau, R.; Bopp, R.F.

    1993-01-01

    There are several methods for determining sediment accumulation rates in the Hudson River estuary. One involves the analysis of the concentration of certain radionuclides in sediment core sections. Radionuclides occur in the Hudson River as a result of: natural sources, fallout from nuclear weapons testing and low level aqueous releases from the Indian Point Nuclear Power Facility. The following radionuclides have been studied in the authors work: Cesium-137, which is derived from global fallout that started in the 1950's and has peaked in 1963. Beryllium-7, a natural radionuclide with a 53 day half-life and found associated with very recently deposited sediments. Another useful natural radionuclide is Lead-210 derived from the decay of Radon-222 in the atmosphere. Lead-210 has a half-life of 22 years and can be used to date sediments up to about 100 years old. In the Hudson River, Cobalt-60 is a marker for Indian Point Nuclear Reactor discharges. The author's research involved taking sediment core samples from four sites in the Hudson River Estuarine Research Reserve areas. These core samples were sectioned, dried, ground and analyzed for the presence of radionuclides by the method of gamma-ray spectroscopy. The strength of each current pulse is proportional to the energy level of the gamma ray absorbed. Since different radionuclides produce gamma rays of different energies, several radionuclides can be analyzed simultaneously in each of the samples. The data obtained from this research will be compared to earlier work to obtain a complete chronology of sediment deposition in these Reserve areas of the river. Core samples may then by analyzed for the presence of PCB's, heavy metals and other pollutants such as pesticides to construct a pollution history of the river

  13. Impact of estuarine pollution on birds

    Science.gov (United States)

    Blus, L.J.; Wiemeyer, Stanley N.; Kerwin, J.A.; Stendell, R.C.; Ohlendorf, H.M.; Stickel, L.F.

    1977-01-01

    Pollution of estuaries affects bird populations indirectly through changes in habitat and food supply. The multi-factor pollution of Chesapeake Bay has resulted in diminution of submerged aquatic plants and consequent change in food habits of the canvasback duck. Although dredge-spoil operations can improve wildlife habitat, they often result in its demise. Pollution of estuaries also affects birds directly, through chemical toxication, which may result in outright mortality or in reproductive impairment. Lead from industrial sources and roadways enters the estuaries and is accumulated in tissues of birds. Lead pellets deposited in estuaries as a result of hunting are consumed by ducks with sufficient frequency .to result m large annual die-offs from lead poisoning. Fish in certain areas, usually near industrial sources, may contain levels of mercury high enough to be hazardous to birds that consume them. Other heavy metals are present in estuarine birds, but their significance is poorly known. Oil exerts lethal or sublethal effects on birds by oiling their feathers, oiling eggs and young by contaminated parents, and by ingestion of oil-contaminated food. Organochlorine chemicals, of both agricultural and industrial origin, travel through the food chains and reach harmful levels in susceptible species of birds in certain estuarine ecosystems. Both outright mortality and reproductive impairment have occurred.

  14. Chemistry and behaviour of B, Ca and Mg in interstitial waters of sediments from the coastal and estuarine regions of Mandovi river along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; SenGupta, R.

    Interstitial waters of coastal and estuarine sediments show enrichment of B and Ca and a decrease in Mg. Increase in interstitial B in sediments is due to the downward diffusion from overlying water and release from solid phases by physicochemical...

  15. Metal and trace element sediment assessment from Ribeira do Iguape river, Sao Paulo state, Brazil, by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Francisco J.V. de; Quinaglia, Gilson A., E-mail: franciscovc@cetesbnet.sp.gov.br, E-mail: gilsonn@cetesbnet.sp.gov.br [CETESB - Companhia Ambiental do Estado de Sao Paulo, SP (Brazil). ELTA - Setor de Analises Toxicologicas; Favaro, Deborah I.T., E-mail: defavaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (LAN/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Laboratorio de Analise por Ativacao Neutronica; Franklin, Robson L.; Ferreira, Francisco J., E-mail: robsonf@cetesbnet.sp.gov.br, E-mail: franciscoj@cetesbnet.sp.gov.br [CETESB - Companhia Ambiental do Estado de Sao Paulo, SP (Brazil). ELAI - Setor de Quimica Inorganica

    2011-07-01

    The watershed region of the Ribeira do Iguape River and the estuarine complex of the Paranagua-Iguape- Cananeia and the various river basins located between this region and the Atlantic Ocean, is known as the Ribeira Valley. The Ribeira do Iguape River runs a total length of approximately 470 km, being the main source of fresh water in the Estuarine Complex of the Iguape-Cananeia-Paranagua (Lagamar). The Ribeira do Iguape River is the last major river in the State of Sao Paulo that has not been altered by dams. During virtually the entire 20th century, the region of the Ribeira Valley was the scene of constant environmental degradation resulting from the intense exploration and refining of lead, zinc and silver ores that were processed in the mines of the region, in a rudimentary way and without any control over environmental impacts. Since 1996, all such activities ceased, however, leaving behind a huge amount of environmental liabilities. This study aims to investigate the presence and concentration levels of metals and semi-metals arsenic (As), cadmium (Cd) and lead (Pb) in the sediment and water of aquatic systems of Ribeira do Iguape River and its tributaries, for an environmental assessment and monitoring of the region. The determination of these elements was carried out by GF AAS technique for water samples and ICP OES for the sediment samples. This study also assessed the occurrence of some major (Ca, Fe, K and Na), trace (As, Ba, Br, Co, Cs, Hf, Rb, Sb, Sc, Se, Ta, Th, U, Zn) and rare earth elements (La, Ce, Eu, Nd, Sm, Lu, Tb and Yb) by Neutron Activation Analysis (NAA). Validation of both methodologies, according to precision and accuracy, was done by reference material analyses. The results obtained for As, Cd and Pb were compared to the Canadian Environmental oriented values (TEL and PEL). The results obtained for multielemental analyses in the sediment samples were compared to UCC values (Upper Continental Crust). (author)

  16. Metal and trace element sediment assessment from Ribeira do Iguape river, Sao Paulo state, Brazil, by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Castro, Francisco J.V. de; Quinaglia, Gilson A.; Favaro, Deborah I.T.; Franklin, Robson L.; Ferreira, Francisco J.

    2011-01-01

    The watershed region of the Ribeira do Iguape River and the estuarine complex of the Paranagua-Iguape- Cananeia and the various river basins located between this region and the Atlantic Ocean, is known as the Ribeira Valley. The Ribeira do Iguape River runs a total length of approximately 470 km, being the main source of fresh water in the Estuarine Complex of the Iguape-Cananeia-Paranagua (Lagamar). The Ribeira do Iguape River is the last major river in the State of Sao Paulo that has not been altered by dams. During virtually the entire 20th century, the region of the Ribeira Valley was the scene of constant environmental degradation resulting from the intense exploration and refining of lead, zinc and silver ores that were processed in the mines of the region, in a rudimentary way and without any control over environmental impacts. Since 1996, all such activities ceased, however, leaving behind a huge amount of environmental liabilities. This study aims to investigate the presence and concentration levels of metals and semi-metals arsenic (As), cadmium (Cd) and lead (Pb) in the sediment and water of aquatic systems of Ribeira do Iguape River and its tributaries, for an environmental assessment and monitoring of the region. The determination of these elements was carried out by GF AAS technique for water samples and ICP OES for the sediment samples. This study also assessed the occurrence of some major (Ca, Fe, K and Na), trace (As, Ba, Br, Co, Cs, Hf, Rb, Sb, Sc, Se, Ta, Th, U, Zn) and rare earth elements (La, Ce, Eu, Nd, Sm, Lu, Tb and Yb) by Neutron Activation Analysis (NAA). Validation of both methodologies, according to precision and accuracy, was done by reference material analyses. The results obtained for As, Cd and Pb were compared to the Canadian Environmental oriented values (TEL and PEL). The results obtained for multielemental analyses in the sediment samples were compared to UCC values (Upper Continental Crust). (author)

  17. Thallium isotope composition of the upper continental crust and rivers - An investigation of the continental sources of dissolved marine thallium

    Science.gov (United States)

    Nielsen, S.G.; Rehkamper, M.; Porcelli, D.; Andersson, P.; Halliday, A.N.; Swarzenski, P.W.; Latkoczy, C.; Gunther, D.

    2005-01-01

    The thallium (Tl) concentrations and isotope compositions of various river and estuarine waters, suspended riverine particulates and loess have been determined. These data are used to evaluate whether weathering reactions are associated with significant Tl isotope fractionation and to estimate the average Tl isotope composition of the upper continental crust as well as the mean Tl concentration and isotope composition of river water. Such parameters provide key constraints on the dissolved Tl fluxes to the oceans from rivers and mineral aerosols. The Tl isotope data for loess and suspended riverine detritus are relatively uniform with a mean of ??205Tl = -2.0 ?? 0.3 (??205Tl represents the deviation of the 205Tl/203Tl isotope ratio of a sample from NIST SRM 997 Tl in parts per 104). For waters from four major and eight smaller rivers, the majority were found to have Tl concentrations between 1 and 7 ng/kg. Most have Tl isotope compositions very similar (within ??1.5 ??205Tl) to that deduced for the upper continental crust, which indicates that no significant Tl isotope fractionation occurs during weathering. Based on these results, it is estimated that rivers have a mean natural Tl concentration and isotope composition of 6 ?? 4 ng/kg and ??205Tl = -2.5 ?? 1.0, respectively. In the Amazon estuary, both additions and losses of Tl were observed, and these correlate with variations in Fe and Mn contents. The changes in Tl concentrations have much lower amplitudes, however, and are not associated with significant Tl isotope effects. In the Kalix estuary, the Tl concentrations and isotope compositions can be explained by two-component mixing between river water and a high-salinity end member that is enriched in Tl relative to seawater. These results indicate that Tl can display variable behavior in estuarine systems but large additions and losses of Tl were not observed in the present study. Copyright ?? 2005 Elsevier Ltd.

  18. An assessment of landscape characteristics affecting estuarine nitrogen loading in an urban watershed.

    Science.gov (United States)

    Yang, Xiaojun

    2012-02-01

    Exploring the quantitative association between landscape characteristics and the ecological conditions of receiving waters has recently become an emerging area for eco-environmental research. While the landscape-water relationship research has largely targeted on inland aquatic systems, there has been an increasing need to develop methods and techniques that can better work with coastal and estuarine ecosystems. In this paper, we present a geospatial approach to examine the quantitative relationship between landscape characteristics and estuarine nitrogen loading in an urban watershed. The case study site is in the Pensacola estuarine drainage area, home of the city of Pensacola, Florida, USA, where vigorous urban sprawling has prompted growing concerns on the estuarine ecological health. Central to this research is a remote sensor image that has been used to extract land use/cover information and derive landscape metrics. Several significant landscape metrics are selected and spatially linked with the nitrogen loading data for the Pensacola bay area. Landscape metrics and nitrogen loading are summarized by equal overland flow-length rings, and their association is examined by using multivariate statistical analysis. And a stepwise model-building protocol is used for regression designs to help identify significant variables that can explain much of the variance in the nitrogen loading dataset. It is found that using landscape composition or spatial configuration alone can explain most of the nitrogen loading variability. Of all the regression models using metrics derived from a single land use/cover class as the independent variables, the one from the low density urban gives the highest adjusted R-square score, suggesting the impact of the watershed-wide urban sprawl upon this sensitive estuarine ecosystem. Measures towards the reduction of non-point source pollution from urban development are necessary in the area to protect the Pensacola bay ecosystem and its

  19. The use of mechanistic descriptions of algal growth and zooplankton grazing in an estuarine eutrophication model

    Science.gov (United States)

    Baird, M. E.; Walker, S. J.; Wallace, B. B.; Webster, I. T.; Parslow, J. S.

    2003-03-01

    A simple model of estuarine eutrophication is built on biomechanical (or mechanistic) descriptions of a number of the key ecological processes in estuaries. Mechanistically described processes include the nutrient uptake and light capture of planktonic and benthic autotrophs, and the encounter rates of planktonic predators and prey. Other more complex processes, such as sediment biogeochemistry, detrital processes and phosphate dynamics, are modelled using empirical descriptions from the Port Phillip Bay Environmental Study (PPBES) ecological model. A comparison is made between the mechanistically determined rates of ecological processes and the analogous empirically determined rates in the PPBES ecological model. The rates generally agree, with a few significant exceptions. Model simulations were run at a range of estuarine depths and nutrient loads, with outputs presented as the annually averaged biomass of autotrophs. The simulations followed a simple conceptual model of eutrophication, suggesting a simple biomechanical understanding of estuarine processes can provide a predictive tool for ecological processes in a wide range of estuarine ecosystems.

  20. Biophysical processes leading to the ingress of temperate fish larvae into estuarine nursery areas: A review

    Science.gov (United States)

    Teodósio, Maria Alexandra; Paris, Claire B.; Wolanski, Eric; Morais, Pedro

    2016-12-01

    A series of complementary hypotheses have been proposed to explain the recruitment of marine and temperate pelagic fish larvae originated from pelagic eggs in coastal environments. In this review, we propose a new and complementary hypothesis describing the biophysical processes intervening in the recruitment of temperate fish larvae into estuaries. This new hypothesis, the Sense Acuity And Behavioral (SAAB) hypothesis, recognizes that recruitment is unlikely if the larvae drift passively with the water currents, and that successful recruitment requires the sense acuity of temperate fish larvae and their behavioral response to the estuarine cues present in coastal areas. We propose that temperate fish larvae use a hierarchy of sensory cues (odor, sound, visual and geomagnetic cues) to detect estuarine nursery areas and to aid during navigation towards these areas. The sensorial acuity increases along ontogeny, which coincides with increased swimming capabilities. The swimming strategies of post-flexion larvae differ from offshore areas to the tidal zone. In offshore areas, innate behavior might lead larvae towards the coast guided by a sun compass or by the earth's geomagnetic field. In areas under limited influence of estuarine plumes (either in energetic nearshore areas or offshore), post-flexion larvae display a searching swimming behavior for estuarine disconnected patches (infotaxis strategy). After finding an estuarine plume, larvae may swim along the increasing cue concentration to ingress into the estuary. Here, larvae exhibit a rheotaxis behavior and avoid displacement by longshore currents by keeping bearing during navigation. When larvae reach the vicinity of an estuary, merging diel rhythms with feeding and predator avoidance strategies with tidally induced movements is essential to increase their chances of estuarine ingress. A fish larva recruitment model developed for the Ria Formosa lagoon supports the general framework of the SAAB hypothesis. In

  1. Composition, sources, and bioavailability of nitrogen in a longitudinal gradient from freshwater to estuarine waters.

    Science.gov (United States)

    Jani, Jariani; Toor, Gurpal S

    2018-06-15

    Nitrogen (N) transport from land to water is a dominant contributor of N in estuarine waters leading to eutrophication, harmful algal blooms, and hypoxia. Our objectives were to (1) investigate the composition of inorganic and organic N forms, (2) distinguish the sources and biogeochemical mechanisms of nitrate-N (NO 3 -N) transport using stable isotopes of NO 3 - and Bayesian mixing model, and (3) determine the dissolved organic N (DON) bioavailability using bioassays in a longitudinal gradient from freshwater to estuarine ecosystem located in the Tampa Bay, Florida, United States. We found that DON was the most dominant N form (mean: 64%, range: 46-83%) followed by particulate organic N (PON, mean: 22%, range: 14-37%), whereas inorganic N forms (NO x -N: 7%, NH 4 -N: 7%) were 14% of total N in freshwater and estuarine waters. Stable isotope data of NO 3 - revealed that nitrification was the main contributor (36.4%), followed by soil and organic N sources (25.5%), NO 3 - fertilizers (22.4%), and NH 4 + fertilizers (15.7%). Bioassays showed that 14 to 65% of DON concentrations decreased after 5-days of incubation indicating utilization of DON by microbes in freshwater and estuarine waters. These results suggest that despite low proportion of inorganic N forms, the higher concentrations and bioavailability of DON can be a potential source of N for algae and bacteria leading to water quality degradation in the estuarine waters. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Suspended matter and nutrient gradients of a small-scale river plume in Sepetiba Bay, SE-Brazil

    Directory of Open Access Journals (Sweden)

    Raphael Paiva Rodrigues

    2009-04-01

    Full Text Available Coastal river plumes represent one of the final stages of material transport across the land-sea interface. Most studies, however have focused on the behavior of medium to large sized river plumes of coastal-shelf waters, whereas small sized river plumes acting within estuaries have been neglected. This study addressed the behavior of suspended particulate matter (SPM, dissolved inorganic nutrients (DIN, DIP and DSi and Chlorophyll a (Chl. a of a small sized river plume derived from the closely lain São Francisco and Guandú river channels, set in the Sepetiba Bay estuary, SE-Brazil. Two surface water sampling campaigns were conducted, one in January 2003 (humid summer conditions and the other in June 2003 (dry winter conditions. On both occasions, the plumes dispersed in a SE direction towards the inner portion of the bay. The "wet" event plume was more turbid, nutrient rich and dispersed beyond nearshore waters, whereas the "dry" event plume proliferated as a narrow, less turbid and more nutrient poor film alongshore. Both exhibited a marked degree of patchiness, induced by the differential input of materials from the river sources and resuspension processes from the shallow nearshore bottom. The São Francisco river channel was the main source of freshwater, SPM and nutrients, except for ammonia (NH4+-N derived from domestic effluents of the Guandú river. The mesohaline portion of the estuarine mixing zone of the plumes behaved as a slight source for SPM, DSi and DIP, due to bottom resuspension processes. N:P molar ratios ranged between 80:1 and 20:1 along the estuarine gradient, being higher in the summer than in the winter event, indicating that DIP was the potential nutrient limiting primary production. Chl. a concentrations increased at the outer premises of the plume, suggesting that the short residence times and turbidity of the plume waters, hampered primary production nearshore, particularly during the summer occasion. The small

  3. The role of rivers in transporting organic contaminants in the marine environment of Greece

    Science.gov (United States)

    Hatzianestis, Ioannis

    2013-04-01

    The study of trace organic contaminants in coastal marine environments and especially in estuarine systems is of great importance, since these areas, being biologically productive and receiving considerable pollutant inputs from land-based sources via river runoff, act as a transit zone in which contaminants are transported to the sea. The aim of this work is to identify the significance of estuarine export of organic pollution in the marine environment of Greece. For this reason, the distribution, composition and sources of hydrocarbon mixtures were investigated in sediments collected from eight major Greek estuarine systems, by using a molecular marker approach and several diagnostic criteria and indices. Surface sediment samples were collected from the estuaries of five rivers in Northern Greece flowing into Aegean sea (Axios, Aliakmonas, Strymon, Nestos, Evros), one river in Central Greece (Asopos) also flowing into Aegean Sea and two rivers in Western Greece flowing into Ionian sea (Acheloos, Acherontas). The highest aliphatic hydrocarbon concentrations (>100 μg/g), indicative of petroleum pollution, were recorded in Asopos estruaries, followed by Aliakmonas, Axios, Strymon and Evros estuaries (50-100 μg/g). On the contrary, in Nestos delta, as well as in Acheloos and Acherontas estuaries, hydrocarbon values were found low and similar to those measured in open sea (marine environment. The unresolved complex mixture (UCM) was the main component of the aliphatic fraction in most cases demonstrating some petroleum inputs in all areas, but high values of the ratio unresolved to resolved compounds (U/R), which are clearly indicative of petroleum residues, were measured only in Asopos, Axios and Evros estuary (U/R: 5.1-10.4). The n-alkane distribution was generally similar with that of total aliphatics. The high molecular weight n-alkanes (>C23) predominated in most cases, showing an important odd/even carbon number preference (mean CPI values above 5) which is

  4. Recruitment of flatfish species to an estuarine nursery habitat (Lima estuary, NW Iberian Peninsula)

    Science.gov (United States)

    Ramos, Sandra; Ré, Pedro; Bordalo, Adriano A.

    2010-11-01

    One of the present concerns of fish biologists involves defining and identifying nursery habitats in the context of conservation and resource management strategies. Fish nursery studies usually report upon nursery occupation during the latter juvenile stages, despite the fact that recruitment to nurseries can start early in life, during the larval phase. Here we investigated the use of a temperate estuarine nursery area, the Lima estuary (NW Portugal), by initial development stages of flatfish species before and after metamorphosis, integrating the larval and juvenile phases. The Lima estuarine flatfish community comprised twelve taxa, seven of which were present as pelagic larvae, six as juveniles and three as adults. There was a general trend of increasing spring-summer abundance of both larvae and juveniles, followed by a sharp winter decrease, mainly of larval flatfishes. The Lima estuary was used by Solea senegalensis, Platichthys flesus and Solea solea as a nursery area, with direct settlement for the two first species. In contrast, indirect settlement was suggested for S. solea, with metamorphosis occurring outside the estuarine area. Estuarine recruitment of S. senegalensis varied between years, with young larvae occurring in the estuary throughout a prolonged period that lasted 6-9 months, corroborating the protracted spawning season. P. flesus, the second most abundant species, exhibited a typical spring estuarine recruitment, without inter-annual variations. Developed larvae arrived in the estuary during spring, whereas the 0-group juveniles emerged in the following summer period. The present study contributes new insight to our understanding of the economically important S. senegalensis, and highlights the importance of integrating the planktonic larval phase into traditional flatfish nursery studies.

  5. Input of transuranic elements through rivers into the Mediterranean Sea

    International Nuclear Information System (INIS)

    Fukai, R.; Ballestra, S.; Thein, M.

    1981-01-01

    Measurements of 137 Cs, 238 Pu, sup(239+240)Pu and 241 Am were carried out on river water as well as its suspended matter collected seasonally in 1977 from two Mediterranean rivers, the Var and the Rhone. The results show that although the concentrations of the soluble fractions of these radionuclides are higher in the Rhone than in the Var, even the elevated concentrations of soluble 137 Cs (approximately 40 fCi.ltr -1 ) and sup(239+240)Pu (approximately 0.1 fCi.ltr -1 ) in the Rhone are much lower than the average concentrations of these nuclides in Mediterranean surface waters. On the other hand, the concentrations of the nuclides measured in suspended matter are roughly an order of magnitude higher in the Rhone than in the Var. Based on the results of measurements on the two rivers, and assuming that the annual average concentrations of the radionuclides in the Var and the Rhone respectively represent those in radiologically uncontaminated and contaminated Mediterranean rivers, the total inputs of 137 Cs, 238 Pu, sup(239+240)Pu and 241 Am through rivers into the Mediterranean Sea have been estimated. Comparison of these estimated values with the inputs of fallout radionuclides by rain indicates that although local accumulation of transuranic nuclides may be observed on sediments taken from some limited estuarine areas, the geochemical behaviour of transuranic elements in the Mediterranean, as a whole, is exclusively governed today by the fallout input of these elements. (author)

  6. Importance of boreal rivers in providing iron to marine waters.

    Directory of Open Access Journals (Sweden)

    Emma S Kritzberg

    Full Text Available This study reports increasing iron concentrations in rivers draining into the Baltic Sea. Given the decisive role of iron to the structure and biogeochemical function of aquatic ecosystems, this trend is likely one with far reaching consequences to the receiving system. What those consequences may be depends on the fate of the iron in estuarine mixing. We here assess the stability of riverine iron by mixing water from seven boreal rivers with artificial sea salts. The results show a gradual loss of iron from suspension with increasing salinity. However, the capacity of the different river waters to maintain iron in suspension varied greatly, i.e. between 1 and 54% of iron was in suspension at a salinity of 30. The variability was best explained by iron:organic carbon ratios in the riverine waters--the lower the ratio the more iron remained in suspension. Water with an initially low iron:organic carbon ratio could keep even higher than ambient concentrations of Fe in suspension across the salinity gradient, as shown in experiments with iron amendments. Moreover, there was a positive relationship between the molecular size of the riverine organic matter and the amount of iron in suspension. In all, the results point towards a remarkably high transport capacity of iron from boreal rivers, suggesting that increasing concentrations of iron in river mouths may result in higher concentrations of potentially bioavailable iron in the marine system.

  7. Trace metals analysis in estuarine and seawater by ICP-MS using on line preconcentration and matrix elimination with chelating resin.

    Science.gov (United States)

    Nicolaı, M; Rosin, C; Tousset, N; Nicolai, Y

    1999-09-13

    The main difficulties of trace metals analysis in estuarine and seawater stem from their very low concentration (mug/l to sub-mug/l), and, by contrast, the high salt content (up to 38 g/l in the Mediterranean Sea). ICP-MS allows multi-elemental analysis and offers great sensitivity, but may be strongly affected by matrix effects induced by high salt contents (> 1 g/l). To perform trace metals analysis both in riverine, estuarine and seawater, we have developed a hyphenated method: ion chelation chromatography coupled on-line with ICP-MS. Iminodiacetate resin, Metpac CC-1 (Dionex), was used to concentrate most of the trace metals, and to separate them from alkaline and alkaline-earth metals. Behaviour of 17 elements (Pb, Cu, Cd, Ni, U, Cr, Mn, Al, Co, Ga, In, Zn, V, Tl, Bi, Ag and Sn) towards the resin was qualitatively investigated. A method validation, partly derived from AFNOR standard XPT 90-210, was carried out on 12 elements (Pb, Cu, Cd, Ni, U, Cr, Mn, Al, Co, Ga, Bi and In). Replicate measurements of multi-elemental standard solutions were used to check linearity, and to determine repeatability and detection limits. Method accuracy was then assessed by analysing two certified materials: a synthetic freshwater (SRM 1643d), and a natural filtered coastal seawater (NRCC CASS-3). An application assay of natural samples from the Rhône river (France) was eventually carried out, and the analytical results were found to be consistent with previous works.

  8. Three-dimensional simulation of flow, salinity, sediment, and radionuclide movements in the Hudson River estuary

    International Nuclear Information System (INIS)

    Onishi, Y.; Trent, D.S.

    1985-04-01

    The three-dimensional, finite difference model, FLESCOT simulates time-varying movements of flow, turbulent kinetic energy, salinity, water temperature, sediment, and contaminants in estuarine, coastal, and ocean waters. The model was applied to a 106-km (66-mi) reach of the Hudson River estuary in New York between Chelsea and the mouth of the river. It predicted the time-varying, three-dimensional distributions of tidal flow, salinity, three separate groups of sediments (i.e., sand, silt, and clay), and a radionuclide ( 137 Cs) in both dissolved and particulate (those sorbed by sediments) forms for over 40 days. The model also calculated riverbed elevation changes caused by sediment deposition and bed erosion, bed sediment size distribution and armoring, and distributions of the particulate 137 Cs sorbed by sand, silt, and clay in the bed

  9. Carbon Stocks in Mangrove Ecosystems of Musi and Banyuasin Estuarine, South Sumatra Province (Stok Karbon Ekosistem Mangrove di Estuarin Musi dan Banyuasin, Provinsi Sumatera Selatan

    Directory of Open Access Journals (Sweden)

    Melki Melki

    2014-09-01

    Full Text Available Hutan mangrove di daerah estuari mampu menghasilkan stok karbon yang sangat besar sebagai daerah perlindungan dan pemulihan yang efektif sebagai strategi mitigasi perubahan iklim yang efektif. Pemilihan ekosistem pesisir dalam strategi mitigasi memerlukan kuantifikasi stok karbon untuk menghitung emisi atau penyerapan berdasarkan waktu. Penelitian ini menghitung stok karbon pada ekosistem Musi Estuari Waters (MEW dan Banyuasin Estuari Water (BEW, Provinsi Sumatera Selatan pada tipe vegetasi yang berbeda dan hubungan variabel lingkungan dengan stok karbon. Di tujuh lokasi dalam MEW dan BEW sampel vegetasi dan tanah. Hasil yang didapatkan adalah nilai yang lebih tinggi dari stok karbon di vegetasi dari lokasi III/MEW (7.600,92 mg.ha-1, stok karbon dalam tanah dari lokasi II/MEW (61.081,87 mg.ha-1 dan stok karbon di ekosistem dari lokasi II (64.548,54 mg.ha-1. Mangrove A. marina merupakan yang paling baik menyimpan stok carbon termasuk antara vegetasi dan tanah karena toleransi salinitas yang rendah. Kata kunci: mangrove, karbon, estuari, Musi, Banyuasin Mangrove forests in estuarines can have exceptionally large carbon stocks and their protection and restoration would constitute an effective mitigation strategy to climate change. Inclusion of coastal ecosystems in mitigation strategies require quantification of carbon stocks in order to calculate emissions or sequestration through time. This study quantified the ecosystem carbon stocks of the Musi Estuarine Waters (MEW and Banyuasin Estuarine Water (BEW, Province of South Sumatra into different vegetation types and examined relationships of environmental variables with carbon stocks. At seven sites within MEW and BEW of vegetation and soil samples. The results that the higher value of carbon stock in vegetation from Site III/MEW (7.600,92 mg.ha-1, the carbon stock in soil from Site II/MEW (61.081,87 mg.ha-1 and carbon stock in ecosystem from Site II (64.548,54 mg.ha-1. Mangrove of A. marina the

  10. Rising tides, cumulative impacts and cascading changes to estuarine ecosystem functions.

    Science.gov (United States)

    O'Meara, Theresa A; Hillman, Jenny R; Thrush, Simon F

    2017-08-31

    In coastal ecosystems, climate change affects multiple environmental factors, yet most predictive models are based on simple cause-and-effect relationships. Multiple stressor scenarios are difficult to predict because they can create a ripple effect through networked ecosystem functions. Estuarine ecosystem function relies on an interconnected network of physical and biological processes. Estuarine habitats play critical roles in service provision and represent global hotspots for organic matter processing, nutrient cycling and primary production. Within these systems, we predicted functional changes in the impacts of land-based stressors, mediated by changing light climate and sediment permeability. Our in-situ field experiment manipulated sea level, nutrient supply, and mud content. We used these stressors to determine how interacting environmental stressors influence ecosystem function and compared results with data collected along elevation gradients to substitute space for time. We show non-linear, multi-stressor effects deconstruct networks governing ecosystem function. Sea level rise altered nutrient processing and impacted broader estuarine services ameliorating nutrient and sediment pollution. Our experiment demonstrates how the relationships between nutrient processing and biological/physical controls degrade with environmental stress. Our results emphasise the importance of moving beyond simple physically-forced relationships to assess consequences of climate change in the context of ecosystem interactions and multiple stressors.

  11. Tidal influence on subtropical estuarine methane emissions

    Science.gov (United States)

    Sturm, Katrin; Grinham, Alistair; Werner, Ursula; Yuan, Zhiguo

    2014-05-01

    The relatively unstudied subtropical estuaries, particularly in the Southern Hemisphere, represent an important gap in our understanding of global greenhouse gas (GHG) emissions. These systems are likely to form an important component of GHG budgets as they occupy a relatively large surface area, over 38 000 km2 in Australia. Here, we present studies conducted in the Brisbane River estuary, a representative system within the subtropical region of Queensland, Australia. This is a highly modified system typical of 80% of Australia's estuaries. Generally, these systems have undergone channel deepening and straightening for safer shipping access and these modifications have resulted in large increases in tidal reach. The Brisbane River estuary's natural tidal reach was 16 km and this is now 85 km and tidal currents influence double the surface area (9 km2 to 18 km2) in this system. Field studies were undertaken to improve understanding of the driving factors behind methane water-air fluxes. Water-air fluxes in estuaries are usually calculated with the gas exchange coefficient (k) for currents and wind as well as the concentration difference across the water-air interface. Tidal studies in the lower and middle reaches of the estuary were performed to monitor the influence of the tidal stage (a proxy for kcurrent) on methane fluxes. Results for both investigated reaches showed significantly higher methane fluxes during the transition time of tides, the time of greatest tidal currents, than during slack tide periods. At these tidal transition times with highest methane chamber fluxes, lowest methane surface water concentrations were monitored. Modelled fluxes using only wind speed (kwind) were at least one order of magnitude lower than observed from floating chambers, demonstrating that current speed was likely the driving factor of water-air fluxes. An additional study was then conducted sampling the lower, middle and upper reaches during a tidal transition period

  12. Formation and entrainment of fluid mud layers in troughs of subtidal dunes in an estuarine turbidity zone

    DEFF Research Database (Denmark)

    Becker, Marius; Schrottke, Kerstin; Bartholomä, Alexander

    2013-01-01

    25 g/L below the lutocline to 70 g/L at the river bed, whereas the gelling concentration was below 70 g/L. Sites of fluid mud formation coincided with the location of the estuarine turbidity zone during slack water. On average, near-bed density gradients were initially observed in dune troughs 1.2 h...... before slack water, and all fluid mud layers were entrained 2.3 h after slack water. No shear instabilities occurred until 1.8 h after slack water. While the flow was oriented in the dune direction, rapid entrainment was related to the development of the turbulent flow field behind dunes and is explained...... to be induced by advection of strong turbulence during accelerating currents. Fluid mud layers in dune troughs were entrained at an earlier point in time after slack water, compared to adjacent layers formed on a comparatively flat bed, where dune crests did not protrude from the lutocline....

  13. Winnowing and Flocculation in Bio-physical Cohesive Substrate: A Flume Experimental and Estuarine Study

    Science.gov (United States)

    Ye, L.; Parsons, D. R.; Manning, A. J.

    2016-12-01

    Cohesive sediment, or mud, is ubiquitously found in most aqueous environments, such as coasts and estuaries. The study of cohesive sediment behaviors requires the synchronous description of mutual interactions of grains (e.g., winnowing and flocculation), their physical properties (e.g., grain size) and also the ambient water. Herein, a series of flume experiments (14 runs) with different substrate mixtures of sand-clay-EPS (Extracellular Polymeric Substrates: secreted by aquatic microorganisms) are combined with an estuarine field survey (Dee estuary, NW England) to investigate the behavior of suspensions over bio-physical cohesive substrates. The experimental results indicate that winnowing and flocculation occur pervasively in bio-physical cohesive flow systems. Importantly however, the evolution of the bed and bedform dynamics and hence turbulence production can be lower when cohesivity is high. The estuarine survey also revealed that the bio-physical cohesion provided by both the clay and microorganism fractions in the bed, that pervasively exists in many natural estuarine systems, plays a significant role in controlling the interactions between bed substrate and sediment suspension and deposition, including controlling processes such as sediment winnowing, flocculation and re-deposition. Full understanding of these processes are essential in advancing sediment transport modelling and prediction studies across natural estuarine systems and the work will report on an improved conceptual model for sediment sorting deposition in bio-physical cohesive substrates.

  14. Using a tiered approach based on ecotoxicological techniques to assess the ecological risks of contamination in a subtropical estuarine protected area.

    Science.gov (United States)

    Campos, B G; Cruz, A C F; Buruaem, L M; Rodrigues, A P C; Machado, W T V; Abessa, D M S

    2016-02-15

    This study sought to assess the ecological risks of sediments from the northern portion of an estuarine protected area (Cananéia-Iguape-Peruíbe Protected Area--CIP-PA). The CIP-PA is located on the southern coast of São Paulo State, Brazil and is influenced by former mining activities along the Ribeira de Iguape River (RIR). We used a tiered approach based on multiple lines of evidence (geochemical analyses, toxicity tests, and whole sediment toxicity identification and evaluation) in order to assess environmental quality. The sediments presented a heterogeneous composition, but the samples collected close to the RIR exhibited higher concentrations of metals (Cd, Cr, Cu, Pb) and toxicity. Multivariate analysis showed that toxicity was associated with metals, mud, organic matter, and CaCO3 quantities. The whole-sediment toxicity identification evaluation approach indicated that ammonia and metals were responsible for sediment toxicity. Overall, we concluded that the sediments collected at depositional areas from the northern portion of the CIP-PA presented high levels of metals, which originated from former mining areas located in the upper RIR basin, and that this contamination had toxic effects on aquatic invertebrates. The tiered approach was useful for identifying the degradation of sediment quality and also for indicating the causes of toxicity. Because the CIP-PA is an important estuarine protected area that is ecologically at risk, large-scale measures are required to control the sources of contamination.

  15. Estuarine environments as rearing habitats for juvenile Coho Salmon in contrasting south-central Alaska watersheds

    Science.gov (United States)

    Hoem Neher, Tammy D.; Rosenberger, Amanda E.; Zimmerman, Christian E.; Walker, Coowe M.; Baird, Steven J.

    2013-01-01

    For Pacific salmon, estuaries are typically considered transitional staging areas between freshwater and marine environments, but their potential as rearing habitat has only recently been recognized. The objectives of this study were two-fold: (1) to determine if Coho Salmon Oncorhynchus kisutch were rearing in estuarine habitats, and (2) to characterize and compare the body length, age, condition, and duration and timing of estuarine occupancy of juvenile Coho Salmon between the two contrasting estuaries. We examined use of estuary habitats with analysis of microchemistry and microstructure of sagittal otoliths in two watersheds of south-central Alaska. Juvenile Coho Salmon were classified as estuary residents or nonresidents (recent estuary immigrants) based on otolith Sr : Ca ratios and counts of daily growth increments on otoliths. The estuaries differed in water source (glacial versus snowmelt hydrographs) and in relative estuarine and watershed area. Juvenile Coho Salmon with evidence of estuary rearing were greater in body length and condition than individuals lacking evidence of estuarine rearing. Coho Salmon captured in the glacial estuary had greater variability in body length and condition, and younger age-classes predominated the catch compared with the nearby snowmelt-fed, smaller estuary. Estuary-rearing fish in the glacial estuary arrived later and remained longer (39 versus 24 d of summer growth) during the summer than did fish using the snowmelt estuary. Finally, we observed definitive patterns of overwintering in estuarine and near shore environments in both estuaries. Evidence of estuary rearing and overwintering with differences in fish traits among contrasting estuary types refute the notion that estuaries function as only staging or transitional habitats in the early life history of Coho Salmon.

  16. Trace elements and heavy metals in the Grand Bay National Estuarine Reserve in the northern Gulf of Mexico

    Science.gov (United States)

    The Grand Bay National Estuarine Research Reserve has the highest biotic diversity of habitats and offer a reserve of food resources and commercially significant species. Rapid human civilization has led to accumulation of heavy metals and trace elements in estuaries. The Grand Bay National Estuarin...

  17. Estuarine use by spotted grunter Pomadasys commersonnii in a ...

    African Journals Online (AJOL)

    Factors influencing estuarine use and marine excursions by spotted grunter Pomadasys commersonnii in the Great Fish Estuary, South Africa, were studied using manual and automated telemetry methods. In all, 20 individuals, ranging from 362 mm to 698 mm total length (TL), were caught and tagged with acousticcoded ...

  18. Terrestrial contributions to the aquatic food web in the middle Yangtze River.

    Science.gov (United States)

    Wang, Jianzhu; Gu, Binhe; Huang, Jianhui; Han, Xingguo; Lin, Guanghui; Zheng, Fawen; Li, Yuncong

    2014-01-01

    Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD) in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish) at an upstream constricted-channel site (Luoqi), a midstream estuarine site (Huanghua) and a near dam limnetic site (Maoping) of the TGD were collected for stable isotope (δ13C and δ15N) and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping), particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies.

  19. CHEMOSENSORY ATTRACTION OF ZOOSPORES OF THE ESTUARINE DINOFLAGELLATES, PFIESTERIA PISCICIDA AND P. SHUMWAYAE, TO FINFISH MUCUS AND EXCRETA. (R825551)

    Science.gov (United States)

    Toxic strains of the estuarine dinoflagellates, Pfiesteria piscicida and P. shumwayae, can cause fish death and disease, whereas other estuarine `lookalike' species such as cryptoperidiniopsoids have not been ichthyotoxic under ecologically rel...

  20. Benthic and pelagic pathways of methylmercury bioaccumulation in estuarine food webs of the northeast United States.

    Directory of Open Access Journals (Sweden)

    Celia Y Chen

    Full Text Available Methylmercury (MeHg is a contaminant of global concern that bioaccumulates and bioamagnifies in marine food webs. Lower trophic level fauna are important conduits of MeHg from sediment and water to estuarine and coastal fish harvested for human consumption. However, the sources and pathways of MeHg to these coastal fisheries are poorly known particularly the potential for transfer of MeHg from the sediment to biotic compartments. Across a broad gradient of human land impacts, we analyzed MeHg concentrations in food webs at ten estuarine sites in the Northeast US (from the Hackensack Meadowlands, NJ to the Gulf of Maine. MeHg concentrations in water column particulate material, but not in sediments, were predictive of MeHg concentrations in fish (killifish and Atlantic silversides. Moreover, MeHg concentrations were higher in pelagic fauna than in benthic-feeding fauna suggesting that MeHg delivery to the water column from methylation sites from within or outside of the estuary may be an important driver of MeHg bioaccumulation in estuarine pelagic food webs. In contrast, bulk sediment MeHg concentrations were only predictive of concentrations of MeHg in the infaunal worms. Our results across a broad gradient of sites demonstrate that the pathways of MeHg to lower trophic level estuarine organisms are distinctly different between benthic deposit feeders and forage fish. Thus, even in systems with contaminated sediments, transfer of MeHg into estuarine food webs maybe driven more by the efficiency of processes that determine MeHg input and bioavailability in the water column.

  1. Behaviour of fluoride and dissolved silicon in Gouthami Godavari estuarine environment

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.; Sudhakar, U.; Varaprasad, S.J.D.

    The concentrations of fluoride and dissolved silicon in Gouthami-Godavari estuarine region (Andhra Pradesh, India) have been measured as a function of chlorinity during different seasons. Fluoride and dissolved silicon behave conservatively during...

  2. North Inlet-Winyah Bay National Estuarine Research Reserve's (NERR) Estuarine Water Quality Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 1993-2002

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — The North Inlet Estuary and the adjacent lower northeastern section of the Winyah Bay Estuary were designated as part of the National Estuarine Research Reserve...

  3. Investigation of mangrove macroalgae as biomonitors of estuarine metal contamination

    Energy Technology Data Exchange (ETDEWEB)

    Melville, Felicity [Department of Environmental Sciences/Institute of Water and Environmental Resource Management, University of Technology, Sydney, PO Box 123, Broadway NSW 2007 (Australia)], E-mail: f.melville@cqu.edu.au; Pulkownik, Alex [Department of Environmental Sciences/Institute of Water and Environmental Resource Management, University of Technology, Sydney, PO Box 123, Broadway NSW 2007 (Australia)

    2007-11-15

    This study examined the potential use of macroalgae epiphytic on mangrove aerial roots as biomonitors of estuarine contamination. The metal concentrations of macroalgae were investigated in four estuaries in the vicinity of Sydney, Australia, and compared to water and sediment metal concentrations over three seasonal surveys. Macroalgal metal concentrations (copper, zinc, cadmium, chromium, lead, nickel, manganese and iron) appeared to be more associated with sediment metal concentrations than water concentrations, suggesting they may be useful biomonitors of estuarine sediment contamination. Algae in the more contaminated estuaries generally contained higher metal concentrations. However, concentrations of iron, nickel and manganese appeared to be similar in the algae despite the varying sediment concentrations, while accumulation of copper, zinc, lead and chromium appeared to be associated with ambient environmental concentrations. The uptake of metals also varied among the different species, suggesting that algal parameters, such as morphology, may also influence metal uptake and accumulation.

  4. Winter to spring variations of chromophoric dissolved organic matter in a temperate estuary (Po River, northern Adriatic Sea).

    Science.gov (United States)

    Berto, D; Giani, M; Savelli, F; Centanni, E; Ferrari, C R; Pavoni, B

    2010-07-01

    The light absorbing fraction of dissolved organic carbon (DOC), known as chromophoric dissolved organic matter (CDOM) showed wide seasonal variations in the temperate estuarine zone in front of the Po River mouth. DOC concentrations increased from winter through spring mainly as a seasonal response to increasing phytoplankton production and thermohaline stratification. The monthly dependence of the CDOM light absorption by salinity and chlorophyll a concentrations was explored. In 2003, neither DOC nor CDOM were linearly correlated with salinity, due to an exceptionally low Po river inflow. Though the CDOM absorbance coefficients showed a higher content of chromophoric dissolved organic matter in 2004 with respect to 2003, the spectroscopic features confirmed that the qualitative nature of CDOM was quite similar in both years. CDOM and DOC underwent a conservative mixing, only after relevant Po river freshets, and a change in optical features with an increase of the specific absorption coefficient was observed, suggesting a prevailing terrestrial origin of dissolved organic matter. Published by Elsevier Ltd.

  5. Strong links between metal contamination, habitat modification and estuarine larval fish distributions

    Energy Technology Data Exchange (ETDEWEB)

    McKinley, Andrew C., E-mail: andrew.mckinley@hotmail.com [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052 (Australia); Miskiewicz, Anthony [Environment and Recreation, Wollongong City Council, 41 Burelli Street, Wollongong, New South Wales 2500 (Australia); Taylor, Matthew D.; Johnston, Emma L. [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052 (Australia)

    2011-06-15

    Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages. - Highlights: > We examine contamination/habitat modification impacts on larval fish. > Larvae communities differ between modified/unmodified estuaries. > Larvae are more abundant/diverse in modified areas. > Trends are strongly related to sediment metals/seagrass cover. > Larval impacts have wider ecological importance. - We describe strong links between sediment metals contamination, habitat modification and substantial differences in the composition of the estuarine larval fish assemblage.

  6. Insights on the Optical Properties of Estuarine DOM - Hydrological and Biological Influences.

    Directory of Open Access Journals (Sweden)

    Luísa Santos

    Full Text Available Dissolved organic matter (DOM in estuaries derives from a diverse array of both allochthonous and autochthonous sources. In the estuarine system Ria de Aveiro (Portugal, the seasonality and the sources of the fraction of DOM that absorbs light (CDOM were inferred using its optical and fluorescence properties. CDOM parameters known to be affected by aromaticity and molecular weight were correlated with physical, chemical and meteorological parameters. Two sites, representative of the marine and brackish water zones of the estuary, and with different hydrological characteristics, were regularly surveyed along two years, in order to determine the major influences on CDOM properties. Terrestrial-derived compounds are the predominant source of CDOM in the estuary during almost all the year and the two estuarine zones presented distinct amounts, as well as absorbance and fluorescence characteristics. Freshwater inputs have major influence on the dynamics of CDOM in the estuary, in particular at the brackish water zone, where accounted for approximately 60% of CDOM variability. With a lower magnitude, the biological productivity also impacted the optical properties of CDOM, explaining about 15% of its variability. Therefore, climate changes related to seasonal and inter-annual variations of the precipitation amounts might impact the dynamics of CDOM significantly, influencing its photochemistry and the microbiological activities in estuarine systems.

  7. Insights on the Optical Properties of Estuarine DOM - Hydrological and Biological Influences.

    Science.gov (United States)

    Santos, Luísa; Pinto, António; Filipe, Olga; Cunha, Ângela; Santos, Eduarda B H; Almeida, Adelaide

    2016-01-01

    Dissolved organic matter (DOM) in estuaries derives from a diverse array of both allochthonous and autochthonous sources. In the estuarine system Ria de Aveiro (Portugal), the seasonality and the sources of the fraction of DOM that absorbs light (CDOM) were inferred using its optical and fluorescence properties. CDOM parameters known to be affected by aromaticity and molecular weight were correlated with physical, chemical and meteorological parameters. Two sites, representative of the marine and brackish water zones of the estuary, and with different hydrological characteristics, were regularly surveyed along two years, in order to determine the major influences on CDOM properties. Terrestrial-derived compounds are the predominant source of CDOM in the estuary during almost all the year and the two estuarine zones presented distinct amounts, as well as absorbance and fluorescence characteristics. Freshwater inputs have major influence on the dynamics of CDOM in the estuary, in particular at the brackish water zone, where accounted for approximately 60% of CDOM variability. With a lower magnitude, the biological productivity also impacted the optical properties of CDOM, explaining about 15% of its variability. Therefore, climate changes related to seasonal and inter-annual variations of the precipitation amounts might impact the dynamics of CDOM significantly, influencing its photochemistry and the microbiological activities in estuarine systems.

  8. Holocene evolution of the Liaohe Delta, a tide-dominated delta formed by multiple rivers in Northeast China

    Science.gov (United States)

    He, Lei; Xue, Chunting; Ye, Siyuan; Laws, Edward Allen; Yuan, Hongming; Yang, Shixiong; Du, Xiaolei

    2018-02-01

    The Liaohe Delta in Northeast China is one of the ecologically important estuarine deltas in China. It has been formed via the accumulation of sediment discharged by four rivers in the Liaohe Plain that enter Liaodong Bay. Twenty-seven 30-40 m long cores recovered from the Liaohe Plain and Liaodong Bay were analyzed for sedimentary characteristics, grain size, foraminifera species, and ages determined by accelerator mass spectrometry (AMS) 14C to document the stratigraphical sequence and the spatio-temporal evolution of the Liaohe Delta. Our results revealed that the sedimentary environments have evolved from fluvial, tidal flat/estuarine, to neritic and finally to a deltaic environment since the Late Pleistocene. The Holocene transgression arrived at the present coastline at ∼8500 cal a BP and flooded the maximum area of land at ∼7000 cal a BP. A deltaic environment prevailed in this area after 7000 cal a BP. Bounded by the modern Liaohe River mouth, the present deltaic sedimentary system can be divided into the eastern and western components. The rate of seaward progradation of the eastern paleocoastline was estimated to be ∼8.6 m/a since 7000 cal a BP; the eastern cores in the present coastline began receiving the deltaic sediments at ∼5000 cal a BP. The rate of seaward progradation of the western paleocoastline was estimated to be only ∼2.8 m/a since 7000 cal a BP. The coastline on the western side began accumulating deltaic sediments about 2000 years later than the eastern coastline. Depocenter shifting was hypothesized to be the reason for the spatial differences in the sedimentary processes. However, the change of sediment fluxes of the western rivers due to climate changes and ancient human impacts might be the reason for the differences of the temporal evolution of the eastern and western sedimentary systems in the Liaohe Delta.

  9. EFFECTS OF THE CONSTRUCTION OF IRRIGATION RESERVOIRS ON THE DISTRIBUTION OF POLLUTANTS IN ESTUARINE ZONES OF SMALL MEDITERRANEAN RIVERS. THE CASE OF SPERCHIOS RIVER, GREECE

    Directory of Open Access Journals (Sweden)

    Manos Dassenakis

    2009-07-01

    Full Text Available Sperchios is a small river in central Greece and although its estuary has been characterised as an Important Bird Area and is included in the European network “NATURA 2000”, it is very poorly managed from an environmental point of view. The Sperchios basin is one of the most important agricultural regions in Greece but it is influenced also by industrial and urban pollution. An earthen dyke is erected b every summer about 2km upstream from the river mouth in order to collect the river water for irrigation purposes. The change in the site of the intermixing zone due to this fact affects the salinity of the water and the amount of suspended matter as well as the chemical behaviour and partitioning of both heavy metals and nutrients. The suspended matter was found to be the major carrier for most metals e.g. lead, zinc, copper whereas phosphorus was the limiting factor for the phytoplankton growth.

  10. Defense Coastal/Estuarine Research Program (DCERP) Strategic Plan

    Science.gov (United States)

    2007-09-01

    availability to phytoplankton in the water column, as well as to benthic microalgae, macroalgae , and seagrasses in bottom waters (Gallegos et al., 2005...further another of MCBCL’s key management objectives for meeting the requirements of the CWA. How wetlands may be utilized for water treatment ...Regulations Appendix B Prioritized list of MCBCL’s conservation and water quality needs Defense Coastal/Estuarine Research Program (DCERP) Strategic

  11. Modeling and Analysis of Sea-level Rise Impacts on Salinity in the Lower St. Johns River

    Science.gov (United States)

    Bacopoulos, P.

    2015-12-01

    There is deliberate attention being paid to studying sea-level rise impacts on the lower St. Johns River, a drowned coastal plain-type estuary with low topographic drive, located in northeastern Florida. One area of attention is salinity in the river, which influences the entire food web, including sea and marsh grasses, juvenile crustaceans and fishes, wading birds and migratory waterfowl, marine mammals and other predator animals. It is expected that elevated ocean levels will increase the salinity of the estuarine waters, leading to deleterious effects on dependent species of the river biology. The objective of the modeling and analysis was: 1) to establish baseline conditions of salinity for the lower St. Johns River; and 2) to examine future conditions of salinity, as impacted by sea-level rise. Establishing baseline conditions entailed validation of the model for present-day salinity in the lower St. Johns River via comparison to available data. Examining future conditions entailed application of the model for sea-level rise scenarios, with comparison to the baseline conditions, for evaluation of sea-level rise impacts on salinity. While the central focus was on the physics of sea-level rise impacts on salinity, some level of salinity-biological assessment was conducted to identify sea-level rise/salinity thresholds, as related to negatively impacting different species of the river biology.

  12. Microbial degradation of pharmaceuticals in estuarine and coastal seawater

    Energy Technology Data Exchange (ETDEWEB)

    Benotti, Mark J. [Marine Sciences Research Center, Stony Brook University, Stony Brook, NY 11794-5000 (United States); Brownawell, Bruce J. [Marine Sciences Research Center, Stony Brook University, Stony Brook, NY 11794-5000 (United States)], E-mail: bruce.brownawell@sunysb.edu

    2009-03-15

    Microbial degradation rates were measured for 19 pharmaceuticals in estuarine and coastal surface water samples. Antipyrine, carbamazepine, cotinine, sulfamethoxazole, and trimethoprim were the most refractory (half-lives, t{sub 1/2} = 35 to >100 days), making them excellent candidates for wastewater tracers. Nicotine, acetaminophen, and fluoxetine were labile across all treatments (t{sub 1/2} = 0.68-11 days). Caffeine, diltiazem, and nifedipine were also and relatively labile in all but one of the treatments (t{sub 1/2} = 3.5-13 days). Microbial degradation of caffeine was further confirmed by production {sup 14}CO{sub 2}. The fastest decay of non-refractory compounds was always observed in more sewage-affected Jamaica Bay waters. Degradation rates for the majority of these pharmaceuticals are much slower than reported rates for small biomolecules, such as glucose and amino acids. Batch sorption experiments indicate that removal of these soluble pharmaceuticals from the water column to sediments is a relatively insignificant removal process in these receiving waters. - Microbial degradation rates were measured for 19 structurally variable pharmaceuticals in wastewater-impacted estuarine and coastal seawater.

  13. Microbial degradation of pharmaceuticals in estuarine and coastal seawater

    International Nuclear Information System (INIS)

    Benotti, Mark J.; Brownawell, Bruce J.

    2009-01-01

    Microbial degradation rates were measured for 19 pharmaceuticals in estuarine and coastal surface water samples. Antipyrine, carbamazepine, cotinine, sulfamethoxazole, and trimethoprim were the most refractory (half-lives, t 1/2 = 35 to >100 days), making them excellent candidates for wastewater tracers. Nicotine, acetaminophen, and fluoxetine were labile across all treatments (t 1/2 = 0.68-11 days). Caffeine, diltiazem, and nifedipine were also and relatively labile in all but one of the treatments (t 1/2 = 3.5-13 days). Microbial degradation of caffeine was further confirmed by production 14 CO 2 . The fastest decay of non-refractory compounds was always observed in more sewage-affected Jamaica Bay waters. Degradation rates for the majority of these pharmaceuticals are much slower than reported rates for small biomolecules, such as glucose and amino acids. Batch sorption experiments indicate that removal of these soluble pharmaceuticals from the water column to sediments is a relatively insignificant removal process in these receiving waters. - Microbial degradation rates were measured for 19 structurally variable pharmaceuticals in wastewater-impacted estuarine and coastal seawater

  14. Ecotoxicology of bromoacetic acid on estuarine phytoplankton

    International Nuclear Information System (INIS)

    Gordon, Ana R.; Richardson, Tammi L.; Pinckney, James L.

    2015-01-01

    Bromoacetic acid is formed when effluent containing chlorine residuals react with humics in natural waters containing bromide. The objective of this research was to quantify the effects of bromoacetic acid on estuarine phytoplankton as a proxy for ecosystem productivity. Bioassays were used to measure the EC 50 for growth in cultured species and natural marine communities. Growth inhibition was estimated by changes in chlorophyll a concentrations measured by fluorometry and HPLC. The EC 50 s for cultured Thalassiosira pseudonana were 194 mg L −1 , 240 mg L −1 for Dunaliella tertiolecta and 209 mg L −1 for Rhodomonas salina. Natural phytoplankton communities were more sensitive to contamination with an EC 50 of 80 mg L −1 . Discriminant analysis suggested that bromoacetic acid additions cause an alteration of phytoplankton community structure with implications for higher trophic levels. A two-fold EC 50 decrease in mixed natural phytoplankton populations affirms the importance of field confirmation for establishing water quality criteria. - Highlights: • Bromoacetic acid exposure resulted in lethal impacts to estuarine phytoplankton. • Cultured phytoplankton were less sensitive to bromoacetic acid than natural communities. • Lab results should be confirmed with field experiments whenever possible. - The toxicology of haloacetic acids has been studied in freshwater ecosystems, and urbanization of the coastal zone is making effects in marine ecosystems equally relevant.

  15. Assessment of the ecotoxicity of urban estuarine sediment using benthic and pelagic copepod bioassays

    Directory of Open Access Journals (Sweden)

    Maria P. Charry

    2018-05-01

    Full Text Available Urban estuarine sediments are sinks to a range of contaminants of anthropogenic origin, and a key challenge is to characterize the risk of these compounds to receiving environments. In this study, the toxicity of urban estuarine sediments was tested using acute and chronic bioassays in the benthic harpacticoid Quinquelaophonte sp., and in the planktonic calanoid Gladioferens pectinatus, two New Zealand copepod species. The sediment samples from the estuary tributary sites significantly impacted reproduction in Quinquelaophonte sp. However, results from one of the estuary sites were not significantly different to those from the tributaries sites, suggesting that chemicals other than trace metals, polycyclic aromatic hydrocarbons and ammonia may be the causative stressors. Sediment elutriate samples had significant effects on reproductive endpoints in G. pectinatus, and on the induction of DNA damage in cells, as shown by the comet assay. The results indicate that sediment contamination at the Ahuriri Estuary has the potential to impact biological processes of benthic and pelagic organisms. The approach used provides a standardized methodology to assess the toxicity of estuarine sediments.

  16. Assessment of the ecotoxicity of urban estuarine sediment using benthic and pelagic copepod bioassays.

    Science.gov (United States)

    Charry, Maria P; Keesing, Vaughan; Costello, Mark; Tremblay, Louis A

    2018-01-01

    Urban estuarine sediments are sinks to a range of contaminants of anthropogenic origin, and a key challenge is to characterize the risk of these compounds to receiving environments. In this study, the toxicity of urban estuarine sediments was tested using acute and chronic bioassays in the benthic harpacticoid Quinquelaophonte sp., and in the planktonic calanoid Gladioferens pectinatus , two New Zealand copepod species. The sediment samples from the estuary tributary sites significantly impacted reproduction in Quinquelaophonte sp. However, results from one of the estuary sites were not significantly different to those from the tributaries sites, suggesting that chemicals other than trace metals, polycyclic aromatic hydrocarbons and ammonia may be the causative stressors. Sediment elutriate samples had significant effects on reproductive endpoints in G. pectinatus , and on the induction of DNA damage in cells, as shown by the comet assay. The results indicate that sediment contamination at the Ahuriri Estuary has the potential to impact biological processes of benthic and pelagic organisms. The approach used provides a standardized methodology to assess the toxicity of estuarine sediments.

  17. Discontinuous Galerkin modeling of the Columbia River's coupled estuary-plume dynamics

    Science.gov (United States)

    Vallaeys, Valentin; Kärnä, Tuomas; Delandmeter, Philippe; Lambrechts, Jonathan; Baptista, António M.; Deleersnijder, Eric; Hanert, Emmanuel

    2018-04-01

    The Columbia River (CR) estuary is characterized by high river discharge and strong tides that generate high velocity flows and sharp density gradients. Its dynamics strongly affects the coastal ocean circulation. Tidal straining in turn modulates the stratification in the estuary. Simulating the hydrodynamics of the CR estuary and plume therefore requires a multi-scale model as both shelf and estuarine circulations are coupled. Such a model has to keep numerical dissipation as low as possible in order to correctly represent the plume propagation and the salinity intrusion in the estuary. Here, we show that the 3D baroclinic discontinuous Galerkin finite element model SLIM 3D is able to reproduce the main features of the CR estuary-to-ocean continuum. We introduce new vertical discretization and mode splitting that allow us to model a region characterized by complex bathymetry and sharp density and velocity gradients. Our model takes into account the major forcings, i.e. tides, surface wind stress and river discharge, on a single multi-scale grid. The simulation period covers the end of spring-early summer of 2006, a period of high river flow and strong changes in the wind regime. SLIM 3D is validated with in-situ data on the shelf and at multiple locations in the estuary and compared with an operational implementation of SELFE. The model skill in the estuary and on the shelf indicate that SLIM 3D is able to reproduce the key processes driving the river plume dynamics, such as the occurrence of bidirectional plumes or reversals of the inner shelf coastal currents.

  18. Phytoplankton characteristics in a polluted Bombay Harbour-Thana-Bassein creek estuarine complex

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, Neelam; Ramaiah, N.; Nair, V.R.

    Annual variations in phytoplankton characteristics were studied from Bombay Harbour-Thana creek-Bassein creek (BHTCBC) estuarine confluence to assess the levels of pigment concentration, productivity and, qualitative and qunatitative nature...

  19. A two-dimensional analytical model for groundwater flow in a leaky aquifer extending finite distance under the estuary

    Science.gov (United States)

    Chuang, Mo-Hsiung; Hung, Chi-Tung; -Yen Lin, Wen; Ma, Kuo-chen

    2017-04-01

    In recent years, cities and industries in the vicinity of the estuarine region have developed rapidly, resulting in a sharp increase in the population concerned. The increasing demand for human activities, agriculture irrigation, and aquaculture relies on massive pumping of water in estuarine area. Since the 1950s, numerous studies have focused on the effects of tidal fluctuations on groundwater flow in the estuarine area. Tide-induced head fluctuation in a two-dimensional estuarine aquifer system is complicated and rather important in dealing with many groundwater management or remediation problems. The conceptual model of the aquifer system considered is multi-layered with estuarine bank and the leaky aquifer extend finite distance under the estuary. The solution of the model describing the groundwater head distribution in such an estuarine aquifer system and subject to the tidal fluctuation effects from estuarine river is developed based on the method of separation of variables along with river boundary. The solutions by Sun (Sun H. A two-dimensional analytical solution of groundwater response to tidal loading in an estuary, Water Resour. Res. 1997; 33:1429-35) as well as Tang and Jiao (Tang Z. and J. J. Jiao, A two-dimensional analytical solution for groundwater flow in a leaky confined aquifer system near open tidal water, Hydrological Processes, 2001; 15: 573-585) can be shown to be special cases of the present solution. On the basis of the analytical solution, the groundwater head distribution in response to estuarine boundary is examined and the influences of leakage, hydraulic parameters, and loading effect on the groundwater head fluctuation due to tide are investigated and discussed. KEYWORDS: analytical model, estuarine river, groundwater fluctuation, leaky aquifer.

  20. Marine and estuarine natural microbial biofilms: ecological and biogeochemical dimensions

    Directory of Open Access Journals (Sweden)

    O. Roger Anderson

    2016-08-01

    Full Text Available Marine and estuarine microbial biofilms are ubiquitously distributed worldwide and are increasingly of interest in basic and applied sciences because of their unique structural and functional features that make them remarkably different from the biota in the plankton. This is a review of some current scientific knowledge of naturally occurring microbial marine and estuarine biofilms including prokaryotic and microeukaryotic biota, but excluding research specifically on engineering and applied aspects of biofilms such as biofouling. Because the microbial communities including bacteria and protists are integral to the fundamental ecological and biogeochemical processes that support biofilm communities, particular attention is given to the structural and ecological aspects of microbial biofilm formation, succession, and maturation, as well as the dynamics of the interactions of the microbiota in biofilms. The intent is to highlight current state of scientific knowledge and possible avenues of future productive research, especially focusing on the ecological and biogeochemical dimensions.

  1. 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

  2. Environmental impact assessment of benthic community stability in an estuarine complex

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Abidi, S.A.H.

    . There was also a substantial decrease in clam production during the 10 year time under consideration. The implication of ever increasing mining rejects in the estuarine system and the utilization of quantitative benthic parameters in environmental impact studies...

  3. Seasonal variations of nitrous oxide fluxes and soil denitrification rates in subtropical freshwater and brackish tidal marshes of the Min River estuary.

    Science.gov (United States)

    Wang, Xuming; Hu, Minjie; Ren, Hongchang; Li, Jiabing; Tong, Chuan; Musenze, Ronald S

    2018-03-01

    Estuarine tidal marshes provide favorable conditions for nitrous oxide (N 2 O) production. Saltwater intrusion caused by sea-level rise would exert complex effects on the production and emission of N 2 O in estuarine tidal marshes; however, few studies have been conducted on its effects on N 2 O emissions. Salinity gradients are a common occurrence in estuarine tidal marshes. Studies on production and emission of N 2 O in tidal marshes with different salinities may elucidate the impact of saltwater intrusion on the emission of greenhouse gases. This study explores the seasonal variations of N 2 O fluxes and soil denitrification rates in freshwater (Daoqingzhou wetland) and brackish (Shanyutan wetland) tidal marshes dominated by Cyperus malaccensis var. brevifolius (shichito matgrass) in the Min River estuary, southeastern China. N 2 O fluxes in both marshes showed strong temporal variability. The highest N 2 O fluxes were observed in the hot and wet summer months, whereas the lowest fluxes were observed in the cold winter and autumn months. N 2 O fluxes from the freshwater marsh (48.81±9.01μgm -2 h -1 ) were significantly higher (ptidal wetlands and exert a negative feedback on the climate system. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Enhancing mud supply from the Lower Missouri River to the Mississippi River Delta USA: Dam bypassing and coastal restoration

    Science.gov (United States)

    Kemp, G. Paul; Day, John W.; Rogers, J. David; Giosan, Liviu; Peyronnin, Natalie

    2016-12-01

    Sand transport to the Mississippi River Delta (MRD) remains sufficient to build wetlands in shallow, sheltered coastal bays fed by engineered diversions on the Mississippi River (MR) and its Atchafalaya River (AR) distributary. But suspended mud (silt & clay) flux to the coast has dropped from a mean of 390 Mt y-1 in the early 1950s, to 100 Mt y-1 since 1970. This fine-grained sediment travels deeper into receiving estuarine basins and plays a critical role in sustaining existing marshes. Virtually all of the 300 Mt y-1 of missing mud once flowed from the Missouri River (MOR) Basin before nearly 100 dams were built as part of the Pick-Sloan water development project. About 100 Mt y-1 is now intercepted by main-stem Upper MOR dams closed in 1953. But the remaining 200 Mt y-1 is trapped by impoundments built on tributaries to the Lower MOR in the 1950s and 1960s. Sediment flux during the post-dam high MOR discharge years of 1973, 1993 and 2011 approached pre-dam levels when tributaries to the Lower MOR, including the Platte and Kansas Rivers, contributed to flood flows. West bank tributaries drain a vast, arid part of the Great Plains, while those entering from the east bank traverse the lowlands of the MOR floodplain. Both provinces are dominated by highly erodible loess soils. Staunching the continued decline in MR fine-grained sediment flux has assumed greater importance now that engineered diversions are being built to reconnect the Lowermost MR to the MRD. Tributary dam bypassing in the Lower MOR basin could increase mud supply to the MRD by 100-200 Mt y-1 within 1-2 decades. Such emergency measures to save the MRD are compatible with objectives of the Missouri River Restoration and Platte River Recovery Programs to restore MOR riparian habitat for endangered species. Rapid mobilization to shunt fine-grained sediments past as many as 50 Lower MOR tributary dams in several U.S. states will undoubtedly require as much regional coordination and funding in the 21st

  5. Multiproxies (benthic foraminifera, ostracods and biopolymers approach applied to identify the environmental partitioning of the Guadiana River Estuary (Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Lazaro Luiz Mattos Laut

    2016-04-01

    Full Text Available The Guadiana River is the fourth longest river in Europe and is a natural frontier between southern Portugal and Spain. This river was historically used to transport minerals exploited in the region since the Roman Empire and therefore suffered human interventions that have been intensified after the industrial revolution. The Guadiana River has in its limits the Guadiana Valley Natural Park, which is of great value for the Conservation of Geobiodiversity. This study mainly aims to identify zones with the environmental characteristics in the estuarine area of the Guadiana River based on the distribution and ecology of microorganisms (ostracods and foraminifera associated with physicochemical parameters and sedimentological and geochemical (carbohydrate, lipid, protein, total organic carbon and total sulfur data. Fifty-five foraminifera taxa were identified along the estuary with dominance of Ammonia tepida and Miliammina fusca and 13 ostracods taxa with dominance Leptocythere lacertosa and Loxoconcha elliptica. Detrended correspondence analysis (DCA performed using biotic and abiotic variables indicated that pH, grain size, total organic carbon (TOC and lipids were the most influent factors in the distribution of these organisms. Four zones were identified in the Guadiana River estuary: i Low estuary - region with the largest marine influence with sandy sediment, higher salinity and total sulfur and mainly represented by the dominance of estuarine species of foraminifera (Ammonia tepida and Cribroelphidium vadescens and by the ostracods (Darwinula stevensoni, Semicytherura sulcata and Urocythereis oblonga; ii Intermediate estuary - region characterized by neutral pH and sandy sediment enriched in carbohydrates; this region is characterized by the presence of the ostracods species Cytherois fischeri and Neocytherideis subulata and by calcareous and agglutinated species in foraminiferal assemblages; iii Upper estuary - silt, high TOC, proteins and

  6. Activity concentration of 210Po and 210Pb, its contribution to the radiation dose and distribution coefficient in aquatic ecosystem of major rivers of coastal Karnataka

    International Nuclear Information System (INIS)

    Rajashekara, K.M.; Prakash, V.; Narayana, Y.

    2013-01-01

    Rivers are the major pathways for the transport of weathered materials from the land to the oceans. The geochemical studies on river waters provide an insight into the weathering process that control the distribution of elements in dissolved and particulate phases and their fluxes to the estuaries. Concentrations of natural series radionuclide in fresh water bodies are liable to be much more variable than those in the marine environment since they are heavily influenced by the local geochemistry of the watershed. The concentrations of radioactive materials vary from region to region and this variation is found to be significantly high in some areas. Some of the regions are rich with the flow of major rivers and estuaries of these rivers, and investigations of these riverine and estuarine aquatic environments would throw light on the transportation, distribution and enrichment mechanism of radionuclides. In this context, the activity of 210 Po and 210 Pb were measured in different matrices of aquatic ecosystem of the major rivers namely, Kali, Sharavathi and Netravathi river of Coastal Karnataka

  7. Estuarine Living Marine Resources: Southeast Regional Distribution and Abundance (NCEI Accession 0163992)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is the original (1991) Southeast regional component of NOAA's Estuarine Living Marine Resources (ELMR) Project, a national database of ecologically and...

  8. Riverbed Micromorphology of the Yangtze River Estuary, China

    Directory of Open Access Journals (Sweden)

    Shuaihu Wu

    2016-05-01

    Full Text Available Dunes are present in nearly all fluvial channels and are vital in understanding sediment transport, deposition, and flow conditions during floods of rivers and estuaries. This information is pertinent for helping developing management practices to reduce risks in river transportation and engineering. Although a few recent studies have investigated the micromorphology of a portion of the Yangtze River estuary in China, our understanding of dune development in this large estuary is incomplete. It is also poorly understood how the development and characteristics of these dunes have been associated with human activities in the upper reach of the Yangtze River and two large-scale engineering projects in the estuarine zone. This study analyzed the feature in micromorphology of the entire Yangtze River estuary bed over the past three years and assessed the morphological response of the dunes to recent human activities. In 2012, 2014, and 2015, multi-beam bathymetric measurements were conducted on the channel surface of the Yangtze River estuary. The images were analyzed to characterize the subaqueous dunes and detect their changes over time. Bottom sediment samples were collected for grain size analysis to assess the physical properties of the dunes. We found that dunes in the Yangtze River estuary can be classified in four major classes: very large dunes, large dunes, medium dunes, and small dunes. Large dunes were predominant, amounting to 51.5%. There was a large area of dunes developed in the middle and upper reaches of the Yangtze River estuary and in the Hengsha Passage. A small area of dunes was observed for the first time in the turbidity maximum zone of the Yangtze River estuary. These dunes varied from 0.12 to 3.12 m in height with a wide range of wavelength from 2.83 to 127.89 m, yielding a range in height to wavelength of 0.003–0.136. Sharp leeside slope angles suggest that the steep slopes of asymmetrical dunes in the middle and upper

  9. Emission of carbon dioxide from a tropical estuarine system, Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; DileepKumar, M.; Manerikar, M.

    Carbon dioxide species were studied in Mandovi-Zuari system, a tropical estuarine complex influenced by strong monsoonal run-off, with implications to build up and air-water exchange of CO sub(2) . Total carbon dioxide (TOC sub(2)) behaved...

  10. Radionuclides in sediments and biota of the south shore the estuary and the initial stretch of the river Tejo (is. Tajo); Radionucleidos en sedimentos y biota de la orilla sur del estuario y del tramo inicial del rio Tajo (es. Tajo)

    Energy Technology Data Exchange (ETDEWEB)

    Corisco, J. A. G.; Portugal, L. M.; Almeida, S.M.

    2013-07-01

    Preliminary data show a trend for which the concentrations of natural radionuclides in sediments surface near the village of Samouco, on the South Bank of the estuarine Bay of yew, is less than that is miden waters above, on a stretch of the River near the village of Valada. (Author)

  11. North Inlet • Winyah Bay (NIW) National Estuarine Research Reserve Meteorological Data, North Inlet Estuary, Georgetown, South Carolina: 2000 • 2004.

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — National Estuarine Research Reserve System The National Estuarine Research Reserve System was established by the Coastal Zone Management Act of 1972 (as amended) and...

  12. Tracing cohesive sediment transportation at river mouths around Tokyo, Japan by Cesium originated from Fukushima Daiichi Power Plant

    Science.gov (United States)

    koibuchi, Y.

    2012-12-01

    Sediment transport at river mouths, which consists of suspended-load and bed-load, has not been fully understood, since bed-load transport of cohesive sand is difficult to observe. Especially, the impact of sediment transport on the total amount of fine-grained cohesive sediment has not been elucidated. Cesium-134 and cesium-137 were spread from the Fukushima Daiichi Nuclear Power Plant (FDNPP) after the earthquake of March 11 of 2011, and attached to the fine-grained sand on the land. The contaminated sand flowed into the river mouths through the rivers possibly due to the complex physical processes in estuarine areas. To evaluate the fine-grained sediment transport around Tokyo and Tokyo Bay, field observations were carried out utilizing radionuclide originated from FDNPP as an effective tracer. The cohesive sediment transport at three different river mouths around Tokyo was successfully quantified. The cohesive sediment transport deposited in the estuary was found to be greatly dependent on the land use, geometry, river discharge and salinity. In addition,the transport driven by the rainfall was minute, and its behavior was quite different from suspended solids. Although further field observations of radionuclide are necessary, it is clear that fine-grained sediment in the bay from rivers already settled on the river mouth by aggregation. The settled sand will not move even in rainfall events. Consequently, the transport of radionuclide to the Pacific Ocean may not occur.; Cesium distribution around Tokyo Bay ; Cesium Concentration in Edogawa river

  13. Bivalve grazing, nutrient cycling and phytoplankton dynamics in an estuarine ecosystem

    NARCIS (Netherlands)

    Prins, T.C.

    1996-01-01


    This thesis has considered the impact of the suspension feeding bivalve Mytilusedulis on nutrient cycling and phytoplankton in an estuarine ecosystem. The research was started within the framework of an extensive research project with the

  14. RELEVANCE OF ROOTED VASCULAR PLANTS AS INDICATORS OF ESTUARINE SEDIMENT QUALITY

    Science.gov (United States)

    Toxicity assessments and numerical quality assessment guidelines for estuarine sediments are rarely based on information for aquatic plants. The effect of this lack of information on contaminated sediment evaluations is largely unknown. For this reason, the toxicities of whole se...

  15. Strong links between metal contamination, habitat modification and estuarine larval fish distributions

    International Nuclear Information System (INIS)

    McKinley, Andrew C.; Miskiewicz, Anthony; Taylor, Matthew D.; Johnston, Emma L.

    2011-01-01

    Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages. - Highlights: → We examine contamination/habitat modification impacts on larval fish. → Larvae communities differ between modified/unmodified estuaries. → Larvae are more abundant/diverse in modified areas. → Trends are strongly related to sediment metals/seagrass cover. → Larval impacts have wider ecological importance. - We describe strong links between sediment metals contamination, habitat modification and substantial differences in the composition of the estuarine larval fish assemblage.

  16. Oregon inlet: Hydrodynamics, volumetric flux and implications for larval fish transport

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, C.R. [National Oceanic and Atmospheric Administration, Silver Springs, MD (United States); Pietrafesa, L.J. [North Carolina State Univ., Raleigh, NC (United States). Department of Marine, Earth and Atmospheric Sciences

    1997-05-01

    The temporal response of Oregon Inlet currents to atmospheric forcing and sea level fluctuations is analyzed using time and frequency domain analysis. Temporally persistent and spatially extensive ebb and flood events are identified using data sets from both within and outside of Oregon Inlet. Prism estimates are made to generate a time series of volumetric flux of water transported through the inlet. Water masses flooding into the Pamlico Sound via Oregon Inlet are identified in temperature (T) and salinity (S) space to determine their source of origin. Correlations are examined between the atmospheric wind field, the main axial slope of the inlet`s water level, inlet flow and T, S properties. Synoptic scale atmospheric wind events are found to dramatically and directly affect the transport of water towards (away from) the inlet on the ocean side, in concert with the contemporaneous transport away from (towards) the inlet on the estuary side, and a subsequent flooding into (out of) the estuary via Oregon Inlet. Thus, while astronomical tidal flooding and ebbing events are shown to be one-sided as coastal waters either set-up or set-down, synoptic scale wind events are shown to be manifested as a two-sided in-phase response set-up and set-down inside and outside the inlet, and thus are extremely effective in driving currents through the inlet. These subinertial frequency flood events are believed to be essential for both the recruitment and subsequent retention of estuarine dependent larval fish from the coastal ocean into Pamlico Sound. Year class strength of these finish may be determined annually by the relative strength and timing of these climatological wind events.

  17. Changes in metal contamination levels in estuarine sediments around India – An assessment

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Ramteke, D.; Chakraborty, S.; Nath, B.N.

    provides managers and decision-makers of environmental protection agency with a better scientific understanding for decision-making in controlling metal pollution in estuarine sediments around India....

  18. Meiobenthos assemblages in the mekong estuarine system with special focus on free-living marine nematodes

    Science.gov (United States)

    Quang, Ngo Xuan; Vanreusel, Ann; Smol, Nic; Chau, Nguyen Ngoc

    2010-12-01

    Meiobenthos assemblages in eight estuaries of the Mekong river system were investigated in August 2008 (from the Cua Tieu estuary to the Tran De estuary). In each estuary, one sampling station was established for meiobenthos sampling. Twelve major taxa of meiobenthos were recorded in this estuarine system, including Nematoda, Copepoda, Turbellaria, Polychaeta, Oligochaeta, Tardigrada, Bivalvia, Ostracoda, Amphipoda, Cumacea, Gastrotricha, Gastropoda, and Crustacean Nauplii larvae. The densities of the meiobenthos range from 581 to 3168 inds/10 cm2. Nematodes always occupy the highest numbers with a percentage ranging from 64-99%. There are 135 nematode genera recorded in this study with the following as dominant genera Desmodora, Leptolaimus, Halalaimus, Thalassomonhystera, Theristus, Daptonema, Rhynchonema, Parodontophora, and Oncholaimus. Although the biodiversity of the meiobenthos at higher taxa level is not high compared to other marine environments, the estimates of nematode biodiversity at the genus level indicates high values. The increase in number of genera with increasing sampling intensity illustrate that the diversity is underestimated and would have been higher if the authors had considered a larger number of individuals, more replicates per station, and more sampling stations.

  19. Relationships between pesticides and organic carbon fractions in sediments of the Danshui River estuary and adjacent coastal areas of Taiwan

    International Nuclear Information System (INIS)

    Hung, C.-C.; Gong, G.-C.; Chen, H.-Y.; Hsieh, H.-L.; Santschi, Peter H.; Wade, Terry L.; Sericano, Jose L.

    2007-01-01

    In order to understand the fate of pesticides in marine environments, concentrations of pesticides and different carbonaceous fractions were determined for surface sediments in the Danshui River and nearby coastal areas of Taiwan. The major compounds detected were tetrachlorobenzene, HCHs, chlordane, aldrin, DDDs, DDEs and DDTs. Total concentrations of pesticides in the sediments ranged from not detectable to 23 ng g -1 , with the maximum value detected near the discharge point of the marine outfall from the Pali sewage treatment plant. These results confirm that pesticides persist in estuarine and nearby coastal environments of the Danshui River well after their ban. Concentrations of total pesticides significantly correlate with concentrations of total organic carbon and black carbon in these sediments, suggesting that total organic carbon and black carbon regulate the distribution of trace organic pollutants in fluvial and coastal marine sediments. - Total organic carbon and black carbon regulate the distribution of trace organic pollutants in sediments of the Danshui River estuary and adjacent coastal areas of Taiwan

  20. Insights on the Optical Properties of Estuarine DOM – Hydrological and Biological Influences

    Science.gov (United States)

    Santos, Luísa; Pinto, António; Filipe, Olga; Cunha, Ângela; Santos, Eduarda B. H.

    2016-01-01

    Dissolved organic matter (DOM) in estuaries derives from a diverse array of both allochthonous and autochthonous sources. In the estuarine system Ria de Aveiro (Portugal), the seasonality and the sources of the fraction of DOM that absorbs light (CDOM) were inferred using its optical and fluorescence properties. CDOM parameters known to be affected by aromaticity and molecular weight were correlated with physical, chemical and meteorological parameters. Two sites, representative of the marine and brackish water zones of the estuary, and with different hydrological characteristics, were regularly surveyed along two years, in order to determine the major influences on CDOM properties. Terrestrial-derived compounds are the predominant source of CDOM in the estuary during almost all the year and the two estuarine zones presented distinct amounts, as well as absorbance and fluorescence characteristics. Freshwater inputs have major influence on the dynamics of CDOM in the estuary, in particular at the brackish water zone, where accounted for approximately 60% of CDOM variability. With a lower magnitude, the biological productivity also impacted the optical properties of CDOM, explaining about 15% of its variability. Therefore, climate changes related to seasonal and inter-annual variations of the precipitation amounts might impact the dynamics of CDOM significantly, influencing its photochemistry and the microbiological activities in estuarine systems. PMID:27195702

  1. Growth Characteristics of an Estuarine Heterocystous Cyanobacterium

    Directory of Open Access Journals (Sweden)

    Pablo Guimarães

    2017-06-01

    Full Text Available A new estuarine filamentous heterocystous cyanobacterium was isolated from intertidal sediment of the Lagoa dos Patos estuary (Brazil. The isolate may represent a new genus related to Cylindrospermopsis. While the latter is planktonic, contains gas vesicles, and is toxic, the newly isolated strain is benthic and does not contain gas vesicles. It is not known whether the new strain is toxic. It grows equally well in freshwater, brackish and full salinity growth media, in the absence of inorganic or organic combined nitrogen, with a growth rate 0.6 d-1. Nitrogenase, the enzyme complex responsible for fixing dinitrogen, was most active during the initial growth phase and its activity was not different between the different salinities tested (freshwater, brackish, and full salinity seawater. Salinity shock also did not affect nitrogenase activity. The frequency of heterocysts was high, coinciding with high nitrogenase activity during the initial growth phase, but decreased subsequently. However, the frequency of heterocysts decreased considerably more at higher salinity, while no change in nitrogenase activity occurred, indicating a higher efficiency of dinitrogen fixation. Akinete frequency was low in the initial growth phase and higher in the late growth phase. Akinete frequency was much lower at high salinity, which might indicate better growth conditions or that akinete differentiation was under the same control as heterocyst differentiation. These trends have hitherto not been reported for heterocystous cyanobacteria but they seem to be well fitted for an estuarine life style.

  2. Characterisation of the hydrology of an estuarine wetland

    Science.gov (United States)

    Hughes, Catherine E.; Binning, Philip; Willgoose, Garry R.

    1998-11-01

    The intertidal zone of estuarine wetlands is characterised by a transition from a saline marine environment to a freshwater environment with increasing distance from tidal streams. An experimental site has been established in an area of mangrove and salt marsh wetland in the Hunter River estuary, Australia, to characterise and provide data for a model of intertidal zone hydrology. The experimental site is designed to monitor water fluxes at a small scale (36 m). A weather station and groundwater monitoring wells have been installed and hydraulic head and tidal levels are monitored over a 10-week period along a short one-dimensional transect covering the transition between the tidal and freshwater systems. Soil properties have been determined in the laboratory and the field. A two-dimensional finite element model of the site was developed using SEEP/W to analyse saturated and unsaturated pore water movement. Modification of the water retention function to model crab hole macropores was found necessary to reproduce the observed aquifer response. Groundwater response to tidal fluctuations was observed to be almost uniform beyond the intertidal zone, due to the presence of highly permeable subsurface sediments below the less permeable surface sediments. Over the 36 m transect, tidal forcing was found to generate incoming fluxes in the order of 0.22 m 3/day per metre width of creek bank during dry periods, partially balanced by evaporative fluxes of about 0.13 m 3/day per metre width. During heavy rainfall periods, rainfall fluxes were about 0.61 m 3/day per metre width, dominating the water balance. Evapotranspiration rates were greater for the salt marsh dominated intertidal zone than the non-tidal zone. Hypersalinity and salt encrustation observed show that evapotranspiration fluxes are very important during non-rainfall periods and are believed to significantly influence salt concentration both in the surface soil matrix and the underlying aquifer.

  3. Polybrominated diphenyl ethers in surface sediments of the Yangtze River Delta: Levels, distribution and potential hydrodynamic influence

    International Nuclear Information System (INIS)

    Chen Shejun; Gao Xiaojiang; Mai Bixian; Chen Zhuomin; Luo Xiaojun; Sheng Guoying; Fu Jiamo; Zeng, Eddy Y.

    2006-01-01

    A total of 32 surface sediments collected from the Yangtze River Estuary, Hangzhou Bay and the Qiantang River were analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of ΣPBDEs (sum of 12 PBDE congeners without BDE 209) and BDE 209 varied from n.d. to 0.55 and from 0.16 to 94.6 ng/g, respectively. The spatial variability of ΣPBDEs concentrations indicated that waste discharge from the urban areas might been the main source of PBDEs in the Yangtze River Delta. BDE 209 was the predominant congener (∼90-100%) detected among the 13 congeners, consistent with the fact that technical deca-BDE mixtures are presently the dominant technical PBDE mixtures used in China. Compared to published data acquired from other locales, PBDE congeners with less than four bromines were more abundant in the present study area. The hydrodynamic conditions may likely be a significant factor in dictating the observed levels and congener distribution patterns of PBDEs. - This study discussed the possible effects of hydrodynamic conditions on the distribution of PBDEs in estuarine and marine boundary

  4. Use of seasonal freshwater wetlands by fishes in a temperate river floodplain

    Science.gov (United States)

    Henning, Julie A.; Gresswell, Robert E.; Fleming, Ian A.

    2007-01-01

    This study examined the use of freshwater wetland restoration and enhancement projects (i.e. non-estuarine wetlands subject to seasonal drying) by fish populations. To quantify fish use of freshwater emergent wetlands and assess the effect of wetland enhancement (i.e. addition of water control structures), two enhanced and two unenhanced emergent wetlands were compared, as well as two oxbow habitats within the Chehalis River floodplain. Eighteen fish species were captured using fyke nets and emigrant traps from January to the beginning of June, with the most abundant being three-spined stickleback Gasterosteus aculeatus and Olympic mudminnow Novumbra hubbsi. Coho salmon Oncorhynchus kisutch was the dominant salmonid at all sites. Enhanced wetlands, with their extended hydroperiods, had significantly higher abundances of yearling coho salmon than unenhanced wetlands. Both enhanced and unenhanced emergent wetlands yielded higher abundances of non-game native fishes than oxbow habitats. Oxbow habitats, however, were dominated by coho salmon. Fish survival in the wetland habitats was dependent on emigration to the river before dissolved oxygen concentrations decreased and wetlands became isolated and stranding occurred. This study suggests that wetland enhancement projects with an outlet to the river channel appear to provide fishes with important temporary habitats if they have the opportunity to leave the wetland as dissolved oxygen levels deteriorate.

  5. Concentrations, loads, and sources of polychlorinated biphenyls, Neponset River and Neponset River Estuary, eastern Massachusetts

    Science.gov (United States)

    Breault, Robert F.

    2011-01-01

    Walter Baker Impoundments were 3,490 and 2,450 ng/g wet wt (filleted) and 6,890 and 4,080 ng/g wet wt (whole fish). Total PCB-congener concentrations measured in the whole bodies of estuarine bait fish (common mummichog) averaged 708 ng/g wet wt. PCBs that pass from the Neponset River to the Neponset River Estuary are either dissolved or associated with particulate matter (including living and nonliving material) suspended in the water column. A small proportion of PCBs may also be transported as part of the body burden of fish and wildlife. During the period May 13, 2005 to April 28, 2006, about 5,100 g (3.8 L or 1 gal) of PCBs were transported from the Neponset River to the Neponset River Estuary. Generally, about one-half of these PCBs were dissolved in the water column and the other half were associated with particulate matter; however, the proportion that was either dissolved or particulate varied seasonally. Most PCBs transported from the river to the estuary are composed of four or fewer chlorine atoms per biphenyl molecule. The data suggest that widespread PCB contamination of the lower Neponset River originated from Mother Brook, a Neponset River tributary, starting sometime around the early 1950s or earlier. In 1955, catastrophic dam failure caused by flooding likely released PCB-contaminated sediment downstream and into the Neponset River Estuary. PCBs from this source area likely continued to be released after the flood and during subsequent rebuilding of downstream dams. Today (2007), PCBs are mostly trapped behind these dams; however, some PCBs either diffuse or are entrained back into the water column and are transported downstream by river water into the estuary or volatilize into the atmosphere. In addition to the continuing release of PCBs from historically contaminated bottom sediment, PCBs are still (2007) originating from source areas along Mother and Meadow Brook as well as other sources along the river and Boston Harbor. PCBs from the river

  6. In Situ Estuarine and Marine Toxicity Testing: A Review, Including Recommendations for Future Use in Ecological Risk Assessment

    Science.gov (United States)

    2009-09-01

    field and microcosms than they do under laboratory test conditions. In the case of tributyltin ( TBT ) exposures in San Diego Bay, he found that...TECHNICAL REPORT 1986 September 2009 In Situ Estuarine and Marine Toxicity Testing A Review, Including Recommendations for Future Use in...Pacific TECHNICAL REPORT 1986 September 2009 In Situ Estuarine and Marine Toxicity Testing A Review, Including Recommendations for Future Use in

  7. Relationship between benthic foraminifera and sediment in the estuarine complex of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Dalal, S.G.

    Two indices of community association were used to elucidate the relationship between changes in species composition of benthic foraminifera and changes in the grain size composition of the sediment in estuarine complex of Goa. The degree...

  8. Terrestrial contributions to the aquatic food web in the middle Yangtze River.

    Directory of Open Access Journals (Sweden)

    Jianzhu Wang

    Full Text Available Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish at an upstream constricted-channel site (Luoqi, a midstream estuarine site (Huanghua and a near dam limnetic site (Maoping of the TGD were collected for stable isotope (δ13C and δ15N and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping, particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies.

  9. Paradigms in the Recovery of Estuarine and Coastal Ecosystems

    OpenAIRE

    Duarte, Carlos M.; Borja, Ángel; Carstensen, Jacob; Elliott, Michael S.; Krause-Jensen, Dorte; Marbà, Núria

    2015-01-01

    © 2013, Coastal and Estuarine Research Federation. Following widespread deterioration of coastal ecosystems since the 1960s, current environmental policies demand ecosystem recovery and restoration. However, vague definitions of recovery and untested recovery paradigms complicate efficient stewardship of coastal ecosystems. We critically examine definitions of recovery and identify and test the implicit paradigms against well-documented cases studies based on a literature review. The study hi...

  10. Collection and analysis of remotely sensed data from the Rhode River Estuary Watershed. [ecological parameters of Chesapeake Bay

    Science.gov (United States)

    Jenkins, D. W.

    1972-01-01

    NASA chose the watershed of Rhode River, a small sub-estuary of the Bay, as a representative test area for intensive studies of remote sensing, the results of which could be extrapolated to other estuarine watersheds around the Bay. A broad program of ecological research was already underway within the watershed, conducted by the Smithsonian Institution's Chesapeake Bay Center for Environmental Studies (CBCES) and cooperating universities. This research program offered a unique opportunity to explore potential applications for remote sensing techniques. This led to a joint NASA-CBCES project with two basic objectives: to evaluate remote sensing data for the interpretation of ecological parameters, and to provide essential data for ongoing research at the CBCES. A third objective, dependent upon realization of the first two, was to extrapolate photointerpretive expertise gained at the Rhode River watershed to other portions of the Chesapeake Bay.

  11. Transport of persistent organic pollutants by microplastics in estuarine conditions

    Science.gov (United States)

    Bakir, Adil; Rowland, Steven J.; Thompson, Richard C.

    2014-03-01

    Microplastics represent an increasing source of anthropogenic contamination in aquatic environments, where they may also act as scavengers and transporters of persistent organic pollutants. As estuaries are amongst the most productive aquatic systems, it is important to understand sorption behaviour and transport of persistent organic pollutants (POPs) by microplastics along estuarine gradients. The effects of salinity sorption equilibrium kinetics on the distribution coefficients (Kd) of phenanthrene (Phe) and 4,4‧-DDT, onto polyvinyl chloride (PVC) and onto polyethylene (PE) were therefore investigated. A salinity gradient representing freshwater, estuarine and marine conditions, with salinities corresponding to 0 (MilliQ water, 690 μS/cm), 8.8, 17.5, 26.3 and 35 was used. Salinity had no significant effect on the time required to reach equilibrium onto PVC or PE and neither did it affect desorption rates of contaminants from plastics. Although salinity had no effect on sorption capacity of Phe onto plastics, a slight decrease in sorption capacity was observed for DDT with salinity. Salinity had little effect on sorption behaviour and POP/plastic combination was shown to be a more important factor. Transport of Phe and DDT from riverine to brackish and marine waters by plastic is therefore likely to be much more dependent on the aqueous POP concentration than on salinity. The physical characteristics of the polymer and local environmental conditions (e.g. plastic density, particle residence time in estuaries) will affect the physical transport of contaminated plastics. A transport model of POPs by microplastics under estuarine conditions is proposed. Transport of Phe and DDT by PVC and PE from fresh and brackish water toward fully marine conditions was the most likely net direction for contaminant transport and followed the order: Phe-PE >> DDT-PVC = DDT-PE >> Phe-PVC.

  12. Marine and Estuarine Ecology. Man and the Gulf of Mexico.

    Science.gov (United States)

    Irby, Bobby N.; And Others

    "Man and the Gulf of Mexico (MGM)" is a marine science curriculum developed to meet the marine science needs of tenth through twelfth grade students in Mississippi and Alabama schools. This MGM unit, which focuses on marine and estuarine ecology, is divided into six sections. The first section contains unit objectives, discussions of the…

  13. Microbial Formation of Ethane in Anoxic Estuarine Sediments

    OpenAIRE

    Oremland, Ronald S.

    1981-01-01

    Estuarine sediment slurries produced methane and traces of ethane when incubated under hydrogen. Formation of methane occurred over a broad temperature range with an optimum above 65°C. Ethane formation had a temperature optimum at 40°C. Formation of these two gases was inhibited by air, autoclaving, incubation at 4 and 80°C, and by the methanogenic inhibitor, 2-bromoethanesulfonic acid. Ethane production was stimulated by addition of ethylthioethanesulfonic acid, and production from ethylthi...

  14. Ecoengineering with Ecohydrology: Successes and failures in estuarine restoration

    Science.gov (United States)

    Elliott, Michael; Mander, Lucas; Mazik, Krysia; Simenstad, Charles; Valesini, Fiona; Whitfield, Alan; Wolanski, Eric

    2016-07-01

    Ecological Engineering (or Ecoengineering) is increasingly used in estuaries to re-create and restore ecosystems degraded by human activities, including reduced water flow or land poldered for agricultural use. Here we focus on ecosystem recolonization by the biota and their functioning and we separate Type A Ecoengineering where the physico-chemical structure is modified on the basis that ecological structure and functioning will then follow, and Type B Ecoengineering where the biota are engineered directly such as through restocking or replanting. Modifying the physical system to create and restore natural processes and habitats relies on successfully applying Ecohydrology, where suitable physical conditions, especially hydrography and sedimentology, are created to recover estuarine ecology by natural or human-mediated colonisation of primary producers and consumers, or habitat creation. This successional process then allows wading birds and fish to reoccupy the rehabilitated areas, thus restoring the natural food web and recreating nursery areas for aquatic biota. We describe Ecohydrology principles applied during Ecoengineering restoration projects in Europe, Australia, Asia, South Africa and North America. These show some successful and sustainable approaches but also others that were less than successful and not sustainable despite the best of intentions (and which may even have harmed the ecology). Some schemes may be 'good for the ecologists', as conservationists consider it successful that at least some habitat was created, albeit in the short-term, but arguably did little for the overall ecology of the area in space or time. We indicate the trade-offs between the short- and long-term value of restored and created ecosystems, the success at developing natural structure and functioning in disturbed estuaries, the role of this in estuarine and wetland management, and the costs and benefits of Ecoengineering to the socio-ecological system. These global case

  15. Characterisation of the suspended particulate matter in a stratified estuarine environment employing complementary techniques

    Science.gov (United States)

    Thomas, Luis P.; Marino, Beatriz M.; Szupiany, Ricardo N.; Gallo, Marcos N.

    2017-09-01

    The ability to predict the sediment and nutrient circulation within estuarine waters is of significant economic and ecological importance. In these complex systems, flocculation is a dynamically active process that is directly affected by the prevalent environmental conditions. Consequently, the floc properties continuously change, which greatly complicates the characterisation of the suspended particle matter (SPM). In the present study, three different techniques are combined in a stratified estuary under quiet weather conditions and with a low river discharge to search for a solution to this problem. The challenge is to obtain the concentration, size and flux of suspended elements through selected cross-sections using the method based on the simultaneous backscatter records of 1200 and 600 kHz ADCPs, isokinetic sampling data and LISST-25X measurements. The two-ADCP method is highly effective for determining the SPM size distributions in a non-intrusive way. The isokinetic sampling and the LISST-25X diffractometer offer point measurements at specific depths, which are especially useful for calibrating the ADCP backscatter intensity as a function of the SPM concentration and size, and providing complementary information on the sites where acoustic records are not available. Limitations and potentials of the techniques applied are discussed.

  16. Aggregation, sedimentation, dissolution and bioavailability of quantum dots in estuarine systems.

    Science.gov (United States)

    To understand their fate and transport in estuarine systems, the aggregation, sedimentation, and dissolution of CdSe quantum dots (QDs) in seawater were investigated. Hydrodynamic size increased from 40 to 60 nm to >1 mm within 1 h in seawater, and the aggregates were highly p...

  17. Does estuarine health relate to catchment land-cover in the East ...

    African Journals Online (AJOL)

    Possible links between catchment and buffer zone land-cover class composition and the health of the East Kleinemonde Estuary were explored. There was a relationship between catchment land-cover and estuarine health within all assessed catchment delineations. Natural land-cover was determined to be the best ...

  18. Assessment of natural radium isotopes and 222Rn in water samples from Cananeia-Iguape estuarine complex, Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Oliveira, Joselene de; Jesus, Sueli Carvalho de; Abrahao, Fernanda Franco; Santos, Glorivania Ferreira dos; Braga, Elisabete de Santis; Chiozzini, Vitor

    2009-01-01

    Radium isotopes and radon are among the most important natural radionuclides in the environment from both radioprotection and geo-hydrological points of view. These radionuclides are a powerful tool for studying coastal processes and have been used intensively as tracers of groundwater sources that discharge into the ocean. In this paper, naturally occurring radium isotopes and 222 Rn were determined to trace water exchange and SGD in Cananeia-Iguape estuarine complex, a shallow coastal plain estuary in southern Sao Paulo area. The research work was carried out during the first semester of 2009 and covered stations located both in Cananeia and Iguape outlets, as well as samples collected in Ribeira of Iguape River and groundwater. Activity concentrations of 226 Ra in estuarine waters from Cananeia outlet varied from 2.9 mBq L -1 to 4.7 mBq L -1 , while 228 Ra concentrations ranged from 22 mBq L -1 to 45 mBq L -1 . In Iguape outlet, activities of 226 Ra ranged from 1.6 mBq L -1 to 6.6 mBq L -1 ; 228 Ra varied from 13 mBq L -1 to 20 mBq L -1 . Activities of Ra were slightly higher in samples collected at 5 m depth than at the surface water level. Groundwater activity concentrations of 226 Ra ranged from 0.63 mBq L -1 to 12 mBq L -1 and for 228 Ra from 18 mBq L -1 to 39 mBq L -1 . In groundwater, the 228 Ra/ 226 Ra activity ratios varied from 3.3 to 31.7. 222 Rn activities in groundwater up to 747 Bq L -1 were observed. Increased nitrate contents were observed in groundwater samples collected in Cananeia and Comprida Island. (author)

  19. Heavy metal anomalies in the Tinto and Odiel River and estuary system, Spain

    Science.gov (United States)

    Nelson, C.H.; Lamothe, P.J.

    1993-01-01

    The Tinto and Odiel rivers drain 100 km from the Rio Tinto sulphide mining district, and join at a 20-km long estuary entering the Atlantic Ocean. A reconnaissance study of heavy metal anomalies in channel sand and overbank mud of the river and estuary by semi-quantitative emission dc-arc spectrographic analysis shows the following upstream to downstream ranges in ppm (??g g-1): As 3,000 to TOC), sandysilty overbank clay has been analyzed to represent suspended load materials. The high content of heavy metals in the overbank clay throughout the river and estuary systems indicates the importance of suspended sediment transport for dispersing heavy metals from natural erosion and anthropogenic mining activities of the sulfide deposit. The organic-poor (0.21-0.37% TOC) river bed sand has been analyzed to represent bedload transport of naturally-occurring sulfide minerals. The sand has high concentrations of metals upstream but these decrease an order of magnitude in the lower estuary. Although heavy metal contamination of estuary mouth beach sand has been diluted to background levels estuary mud exhibits increased contamination apparently related to finer grain size, higher organic carbon content, precipitation of river-borne dissolved solids, and input of anthropogenic heavy metals from industrial sources. The contaminated estuary mud disperses to the inner shelf mud belt and offshore suspended sediment, which exhibit metal anomalies from natural erosion and mining of upstream Rio Tinto sulphide lode sources (Pb, Cu, Zn) and industrial activities within the estuary (Fe, Cr, Ti). Because heavy metal contamination of Tinto-Odiel river sediment reaches or exceeds the highest levels encountered in other river sediments of Spain and Europe, a detailed analysis of metals in water and suspended sediment throughout the system, and epidemiological analysis of heavy metal effects in humans is appropriate. ?? 1993 Estuarine Research Federation.

  20. Physico-chemical characteristics of the Mahanadi estuarine ecosystem, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Upadhyay, S.

    mixed coastal plain estuary. The oxygen concentration in this estuarine system is closely related to biological activity and hence to seasonal changes in pH and it bears an inverse relationship with salinity structure. Dissolved nutrients are mostly non...

  1. Tributyltin-resistant bacteria from estuarine and freshwater sediments.

    OpenAIRE

    Wuertz, S; Miller, C E; Pfister, R M; Cooney, J J

    1991-01-01

    Resistance to tributyltin (TBT) was examined in populations from TBT-polluted sediments and nonpolluted sediments from an estuary and from fresh water as well as in pure cultures isolated from those sediments. The 50% effective concentrations (EC50s) for populations were higher at a TBT-polluted freshwater site than at a site without TBT, suggesting that TBT selected for a TBT-resistant population. In contrast, EC50s were significantly lower for populations from a TBT-contaminated estuarine s...

  2. Turbine sound may influence the metamorphosis behaviour of estuarine crab megalopae.

    Science.gov (United States)

    Pine, Matthew K; Jeffs, Andrew G; Radford, Craig A

    2012-01-01

    It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the potential environmental impacts. This study investigated how the sound emitted from an underwater tidal turbine and an offshore wind turbine would influence the settlement and metamorphosis of the pelagic larvae of estuarine brachyuran crabs which are ubiquitous in most coastal habitats. In a laboratory experiment the median time to metamorphosis (TTM) for the megalopae of the crabs Austrohelice crassa and Hemigrapsus crenulatus was significantly increased by at least 18 h when exposed to either tidal turbine or sea-based wind turbine sound, compared to silent control treatments. Contrastingly, when either species were subjected to natural habitat sound, observed median TTM decreased by approximately 21-31% compared to silent control treatments, 38-47% compared to tidal turbine sound treatments, and 46-60% compared to wind turbine sound treatments. A lack of difference in median TTM in A. crassa between two different source levels of tidal turbine sound suggests the frequency composition of turbine sound is more relevant in explaining such responses rather than sound intensity. These results show that estuarine mudflat sound mediates natural metamorphosis behaviour in two common species of estuarine crabs, and that exposure to continuous turbine sound interferes with this natural process. These results raise concerns about the potential ecological impacts of sound generated by renewable energy generation systems placed in the nearshore environment.

  3. Tropical Estuarine Macrobenthic Communities Are Structured by Turnover Rather than Nestedness.

    Science.gov (United States)

    Medeiros, Carlinda Raílly; Hepp, Luiz Ubiratan; Patrício, Joana; Molozzi, Joseline

    2016-01-01

    Turnover (i.e., species substitution) and nestedness (i.e., subsets of species from more diverse locations), the two main mechanisms used to explain the beta diversity of biological communities, have different implications for biodiversity conservation. To better understand how these mechanisms contribute to beta diversity, we tested the following hypotheses: (i) greater dissimilarity in community composition occurs between estuarine zones than other hierarchical level studied; (ii) beta diversity in these communities develops by turnover in estuaries with a lower degree of anthropogenic impact, but by nestedness in estuaries with a greater degree of anthropogenic impact; and (iii) the structuring mechanism is independent of season. We studied two tropical estuaries (dry and wet seasons) that vary in terms of land-use of the drainage basins. Subtidal benthic macroinvertebrates were sampled along the estuarine gradient in each of the two estuaries. The additive partitioning approach to species diversity was used to determine the hierarchical scale with the greatest dissimilarity in community composition. General beta diversity was measured using the Sorensen dissimilarity index, partitioning the turnover and nestedness components. The greatest dissimilarity in the composition of the communities occurred between the zones along the estuarine gradient in both seasons (dry = 58.6%; wet = 46.3%). In the estuary with a lower degree of anthropogenic influence, benthic macroinvertebrate diversity was generated by turnover regardless of the season. In the estuary with a greater degree of anthropogenic impact, beta diversity was structured by turnover during the dry season and a combination of both mechanisms during the wet season. We conclude that turnover is the principal mechanism responsible for beta diversity in benthic macroinvertebrate communities in tropical estuaries.

  4. Turbine sound may influence the metamorphosis behaviour of estuarine crab megalopae.

    Directory of Open Access Journals (Sweden)

    Matthew K Pine

    Full Text Available It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the potential environmental impacts. This study investigated how the sound emitted from an underwater tidal turbine and an offshore wind turbine would influence the settlement and metamorphosis of the pelagic larvae of estuarine brachyuran crabs which are ubiquitous in most coastal habitats. In a laboratory experiment the median time to metamorphosis (TTM for the megalopae of the crabs Austrohelice crassa and Hemigrapsus crenulatus was significantly increased by at least 18 h when exposed to either tidal turbine or sea-based wind turbine sound, compared to silent control treatments. Contrastingly, when either species were subjected to natural habitat sound, observed median TTM decreased by approximately 21-31% compared to silent control treatments, 38-47% compared to tidal turbine sound treatments, and 46-60% compared to wind turbine sound treatments. A lack of difference in median TTM in A. crassa between two different source levels of tidal turbine sound suggests the frequency composition of turbine sound is more relevant in explaining such responses rather than sound intensity. These results show that estuarine mudflat sound mediates natural metamorphosis behaviour in two common species of estuarine crabs, and that exposure to continuous turbine sound interferes with this natural process. These results raise concerns about the potential ecological impacts of sound generated by renewable energy generation systems placed in the nearshore environment.

  5. Immigration and early life stages recruitment of the European flounder (Platichthys flesus) to an estuarine nursery: The influence of environmental factors

    Science.gov (United States)

    Amorim, Eva; Ramos, Sandra; Elliott, Michael; Bordalo, Adriano A.

    2016-01-01

    Connectivity between coastal spawning grounds and estuarine nurseries is a critical step in the life cycle of many fish species. Larval immigration and transport-associated physical-biological processes are determinants of recruitment success to nursery areas. The recruitment of the European flounder, Platichthys flesus, to estuarine nurseries located at the southern edge of the species distribution range, has been usually investigated during its juvenile stages, while estuarine recruitment during the earlier planktonic life stage remains largely unstudied. The present study investigated the patterns of flounder larval recruitment and the influence of environmental factors on the immigration of the early life stages to the Lima estuary (NW Portugal), integrating data on fish larvae and post-settlement individuals (< 50 mm length), collected over 7 years. Late-stage larvae arrived at the estuary between February and July and peak abundances were observed in April. Post-settlement individuals (< 50 mm) occurred later between April and October, whereas newly-settled ones (< 20 mm) were found only in May and June. Variables associated with the spawning, survival and growth of larvae in the ocean (sea surface temperature, chlorophyll a and inland hydrological variables) were the major drivers of flounder occurrence in the estuarine nursery. Although the adjacent coastal area is characterized by a current system with strong seasonality and mesoscale variability, we did not identify any influence of variables related with physical processes (currents and upwelling) on the occurrence of early life stages in the estuary. A wider knowledge on the influence of the coastal circulation variability and its associated effects upon ocean-estuarine connectivity is required to improve our understanding of the population dynamics of marine spawning fish that use estuarine nurseries.

  6. Characterization of the current biological communities within the Nanticoke River in the vicinity of the Vienna SES

    International Nuclear Information System (INIS)

    Stroup, C.F.; Brindley, A.; Kazyak, P.F.

    1991-07-01

    Pursuant to a utility's intent to file for permission to build a generating station along the Nanticoke River, Maryland, a field program was conducted to update characterizations of major aquatic biota of the river in proximity to the existing power plant and a potential intake/discharge location. This characterization sampled five stations on the Nanticoke River, spanning 14 miles from Chapter Point to Riverton, between July 1988 and October 1989. During the study period, the juvenile and adult fish community was dominated by white perch, Atlantic menhaden, bay anchovy, hogchoker, and spot. Spring ichthyoplankton was composed of white perch, striped bass, yellow perch, and alosids, while summer ichthyoplankton was dominated by naked gobies and bay anchovy. Acartia tonsa, Eurytemora affinis and Bosmina longirostris dominated zooplankton samples. The phytoplankton community was composed primarily of diatoms, green algae, and monads. Polychaetes and crustaceans were the dominant macrobenthic taxa, with molluscs contributing to total abundance primarily during spring recruitment. The final report presents the results of fish, ichthyoplankton, zooplankton, and benthic surveys conducted between July 1988 and October 1989 in the middle portion of the Nanticoke River, Maryland. During the dry conditions of 1988, aquatic communities were dominated by estuarine species, while the lower saline environment of 1989 resulted in the presence of more freshwater species

  7. Diet of Procyon cancrivorus (Carnivora, Procyonidae in restinga and estuarine environments of southern Brazil

    Directory of Open Access Journals (Sweden)

    Fernando M. Quintela

    2014-06-01

    Full Text Available Despite its wide range and abundance on certain habitats, the crab-eating raccoon Procyon cancrivorus (G. Cuvier, 1798 is considered one of the less known Neotropical carnivore species. In the present study we analyzed the diet of P. cancrivorus in a peat forest and in an estuarine island in southernmost Brazil. Fruits of the gerivá palm tree Syagrus romanzoffiana were the most consumed item in the peat forest, followed by insects and mollusks. Small mammals, followed by Bromelia antiacantha (Bromeliaceae fruits and brachyuran crustaceans were the most frequent items in the estuarine island. Other items found in lower frequencies were Solanum sp., Psidium sp., Smilax sp. and Dyospiros sp. fruits, diplopods, scorpions, fishes, anuran amphibians, reptiles (black tegu lizard and snakes, birds and medium-sized mammals (white-eared opossum, armadillo and coypu. Levin’s index values (peat forest: 0.38; estuarine island: 0.45 indicate an approximation to a median position between a specialist and a well distributed diet. Pianka’s index (0.80 showed a considerable diet similarity between the two systems. Procyon cancrivorus presented a varied diet in the studied areas and may play an important role as seed disperser on coastal environments in southernmost Brazil.

  8. Estuarine Living Marine Resources: Mid-Atlantic Regional Distribution and Abundance (NCEI Accession 0162403)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is the Mid-Atlantic regional component of NOAA’s Estuarine Living Marine Resources (ELMR) Project, a national database of ecologically and economically...

  9. Estuarine Living Marine Resources: West Coast Regional Distribution and Abundance (NCEI Accession 0161540)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is the West Coast regional component of NOAA’s Estuarine Living Marine Resources (ELMR) Project, a national database of ecologically and economically...

  10. Estuarine Living Marine Resources: North Atlantic Regional Distribution and Abundance (NCEI Accession 0162402)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is the North Atlantic regional component of NOAA’s Estuarine Living Marine Resources (ELMR) Project, a national database of ecologically and economically...

  11. Santos estuarine sediments, Brazil - metal and trace element assessment by neutron activation analysis

    International Nuclear Information System (INIS)

    Amorim, Eduardo P.; Favaro, Deborah I.T.; Berbel, Glaucia; Braga, Elisabete S.

    2009-01-01

    The Santos estuary system is an intricate pattern of tidal channels and small rivers originating from the adjacent Pre-Cambrian slopes. These two major estuaries share a common area in the upper portion of the region which interacts with each other. The largest harbor in Latin America is located at the eastern outlet of the Santos estuary. This intricate and sensitive ecosystem is highly susceptible to human impact from industrial activities, urban sewage and polluted solid wastes disposal. Due to its high vulnerability CETESB (Environmental Control Agency of the Sao Paulo State) sporadically monitors the contamination levels of water, sediment and marine organisms in this region. The present study reports results concerning the distribution of some major, trace and rare earth elements in the Santos estuarine marine sediments. Thirty two bottom sediment samples (SS0601 to SS0616 (summer) and SW0601 to SW0616 (winter) were collected in this estuary, including regions of Sao Vicente, Santos, Cubatao and Vicente de Carvalho, by a vanVeen sampler in the summer and winter of 2006. Multielemental analysis was carried out by instrumental neutron activation analysis (INAA). The concentration values obtained for As and metals Cr and Zn in the sediment samples were compared to Canadian Council of Minister of the Environment (CCME) oriented values (TEL and PEL values) and are adopted by CETESB. (author)

  12. Santos estuarine sediments, Brazil - metal and trace element assessment by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, Eduardo P.; Favaro, Deborah I.T., E-mail: ducamorim@yahoo.com.b, E-mail: defavaro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil); Berbel, Glaucia; Braga, Elisabete S., E-mail: edsbraga@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. Oceanografico. Lab. de Nutrientes, Micronutrientes e Tracos nos Oceanos (LABNUT)

    2009-07-01

    The Santos estuary system is an intricate pattern of tidal channels and small rivers originating from the adjacent Pre-Cambrian slopes. These two major estuaries share a common area in the upper portion of the region which interacts with each other. The largest harbor in Latin America is located at the eastern outlet of the Santos estuary. This intricate and sensitive ecosystem is highly susceptible to human impact from industrial activities, urban sewage and polluted solid wastes disposal. Due to its high vulnerability CETESB (Environmental Control Agency of the Sao Paulo State) sporadically monitors the contamination levels of water, sediment and marine organisms in this region. The present study reports results concerning the distribution of some major, trace and rare earth elements in the Santos estuarine marine sediments. Thirty two bottom sediment samples (SS0601 to SS0616 (summer) and SW0601 to SW0616 (winter) were collected in this estuary, including regions of Sao Vicente, Santos, Cubatao and Vicente de Carvalho, by a vanVeen sampler in the summer and winter of 2006. Multielemental analysis was carried out by instrumental neutron activation analysis (INAA). The concentration values obtained for As and metals Cr and Zn in the sediment samples were compared to Canadian Council of Minister of the Environment (CCME) oriented values (TEL and PEL values) and are adopted by CETESB. (author)

  13. Thermography of the New River Inlet plume and nearshore currents

    Science.gov (United States)

    Chickadel, C.; Jessup, A.

    2012-12-01

    As part of the DARLA and RIVET experiments, thermal imaging systems mounted on a tower and in an airplane captured water flow in the New River Inlet, NC, USA. Kilometer-scale, airborne thermal imagery of the inlet details the ebb flow of the estuarine plume water mixing with ocean water. Multiple fronts, corresponding to the preferred channels through the ebb tidal delta, are imaged in the aerial data. A series of internal fronts suggest discreet sources of the tidal plume that vary with time. Focused thermal measurements made from a tower on the south side of the inlet viewed an area within a radius of a few hundred meters. Sub-meter resolution video from the tower revealed fine-scale flow features and the interaction of tidal exchange and wave-forced surfzone currents. Using the tower and airborne thermal image data we plan to provide geophysical information to compare with numerical models and in situ measurements made by other investigators. From the overflights, we will map the spatial and temporal extent of the estuarine plume to correlate with tidal phase and local wind conditions. From the tower data, we will investigate the structure of the nearshore flow using a thermal particle image velocimetry (PIV) technique, which is based on tracking motion of the surface temperature patterns. Long term variability of the mean and turbulent two-dimensional PIV currents will be correlated to local wave, tidal, and wind forcing parameters.

  14. A Miocene wave-dominated estuarine system in the Paraíba Basin, northeastern Brazil

    Science.gov (United States)

    Gandini, Rosana; Rossetti, Dilce de Fátima; Netto, Renata Guimarães; Góes, Ana Maria

    2017-11-01

    A number of publications have documented the effect of the Miocene transgression on several coasts of the world. However, this event is incompletely documented along the Brazilian margin, despite the existence of an impressive record of Miocene deposits exposed mostly as several coastal cliffs along more than 5000 km of distance. The transgressive nature of Miocene deposits, so far recognized only in a few localities of northeastern Brazil, needs to be amplified in order to better characterize the impact of the Miocene transgression in eastern South America. In this work, we provide facies analysis of early/middle Miocene strata exposed in the Paraíba Basin, northeastern Brazil, aiming reconstruct the depositional paleoenvironments and analyze their evolution within the context of relative sea-level fluctuations data. The results revealed deposits characterized by several features that were related to the action of tidal currents, such as alternating thicker/thinner forest packages, abundant reactivation surfaces, mud drapes and oppositely-dipping (herringbone) cross sets. These sedimentary structures were associated with an ichnological assemblage indicative of marine-influenced and brackish water, best represented by Ophiomorpha, Planolites-Palaeophycus-Thalassinoides and Thallassinoides-Planolites-Palaeophycus ichnofabrics. Sedimentation occurred in environments consisting of estuarine channel, estuarine central basin, tidal inlet/tidal channel, tidal delta/washover, tidal flat/shoal and foreshore, which were related to an estuarine setting, at least in part of a wave-dominated type. Analysis of facies stratal patterns led to suggest that the estuarine deposits of the Paraíba Basin reflect a rise in relative sea level probably during the transgressive and/or highstand stage of a depositional sequence formed directly overlying Cretaceous rocks. This rise can be correlated with the worldwide early/mid Miocene marine transgression. However, while the eustatic sea

  15. Part I, Introduction: Ecology and Regional Context of Tidal Wetlands in the San Francisco Bay National Estuarine Research Reserve

    Directory of Open Access Journals (Sweden)

    Matthew C. Ferner

    2011-12-01

    Full Text Available This two-part special issue reviews the basic ecology of tidal wetlands in the San Francisco Estuary. Several articles highlight the well-preserved tracts of historic tidal marsh found at China Camp State Park and Rush Ranch Open Space Preserve. These two protected areas serve as important reference sites for wetland restoration and conservation and also comprise San Francisco Bay National Estuarine Research Reserve (SF Bay NERR. SF Bay NERR is part of the National Oceanic and Atmospheric Administration’s nationwide network of 28 estuarine research reserves (http://www.nerrs.noaa.gov that all share common goals: (1 conducting standardized long-term monitoring, (2 supporting applied environmental research, (3 providing stewardship of estuarine natural resources, and (4 linking science with decision making in pursuit of effective solutions to coastal management problems.

  16. Mortality of Kalliapseudes schubartii in unvegetated soft bottoms of the estuarine region of the Lagoa dos Patos

    Directory of Open Access Journals (Sweden)

    Fonseca Duane Barros

    2006-01-01

    Full Text Available Studies were carried iut on seasonal mortality by taking samples of Kalliapseudes schubartii (Crustacea: Tanaidacea for a year in the estuarine region of the Lagoa dos Patos (southern Brazil. Results demonstrated no significant difference in seasonal mortality rates, which suggest that populations of K. schubartii was heavily preyed on year round and that an assumption of a significantly higher mortality in summer/autumn than in spring/winter might not be held in unvegetated soft bottoms of the estuarine regions of the Lagoa dos Patos.

  17. St Lucia is one of the largest estuarine systems in Africa and forms ...

    African Journals Online (AJOL)

    denise

    Board) are the managers of the St Lucia estuarine system and provide .... Linefish System (NMLS), a database maintained by. Marine & Coastal Management, branch of the ...... trawlers operating on the Tugela Bank showed that squaretail kob ...

  18. Analysis of Fluvial Bed Sediments Along the Apalachicola River, Florida through Field Reconnaissance Studies

    Science.gov (United States)

    Passeri, D.; Hagen, S. C.; Daranpob, A.; Smar, D. E.

    2011-12-01

    River competence is an important parameter in understanding sediment transport in fluvial systems. Competence is defined as the measure of a stream's ability to transport a certain maximum grain size of sediment. Studies have shown that bed sediment particle size in rivers and streams tends to vary spatially along the direction of stream flow. Over a river section several reaches long, variability of sediment particle sizes can be seen, often becoming finer downstream. This phenomenon is attributed to mechanisms such as local control of stream gradient, coarse tributary sediment supply or particle breakdown. Average particle size may also be smaller in tributary sections of rivers due to river morphology. The relationship between river mean velocity and particle size that can be transported has also been explored. The Hjulstrom curve classifies this relationship by relating particle size to velocity, dividing the regions of sedimentation, transportation, and erosion. The curve can also be used to find values such as the critical erosion velocity (the velocity required to transport particles of various sizes in suspension) and settling velocity (the velocity at which particles of a given size become too heavy to be transported and fall out of suspension, consequently causing deposition). The purpose of this research is to explore the principles of river competence through field reconnaissance collection and laboratory analysis of fluvial sediment core samples along the Apalachicola River, FL and its distributaries. Sediment core samples were collected in the wetlands and estuarine regions of the Apalachicola River. Sieve and hydrometer analyses were performed to determine the spatial distribution of particle sizes along the river. An existing high resolution hydrodynamic model of the study domain was used to simulate tides and generate river velocities. The Hjulstrom curve and the generated river velocities were used to define whether sediment was being transported

  19. Risk assessment of herbicides and booster biocides along estuarine continuums in the Bay of Vilaine area (Brittany, France).

    Science.gov (United States)

    Caquet, Th; Roucaute, M; Mazzella, N; Delmas, F; Madigou, C; Farcy, E; Burgeot, Th; Allenou, J-P; Gabellec, R

    2013-02-01

    A 2-year study was implemented to characterize the contamination of estuarine continuums in the Bay of Vilaine area (NW Atlantic Coast, Southern Brittany, France) by 30 pesticide and biocide active substances and metabolites. Among these, 11 triazines (ametryn, atrazine, desethylatrazine, desethylterbuthylazine, desisopropyl atrazine, Irgarol 1051, prometryn, propazine, simazine, terbuthylazine, and terbutryn), 10 phenylureas (chlortoluron, diuron, 1-(3,4-dichlorophenyl)-3-methylurea, fenuron, isoproturon, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl)-urea, linuron, metoxuron, and monuron), and 4 chloroacetanilides (acetochlor, alachlor, metolachlor, and metazachlor) were detected at least once. The objectives were to assess the corresponding risk for aquatic primary producers and to provide exposure information for connected studies on the responses of biological parameters in invertebrate sentinel species. The risk associated with contaminants was assessed using risk quotients based on the comparison of measured concentrations with original species sensitivity distribution-derived hazardous concentration values. For EU Water Framework Directive priority substances, results of monitoring were also compared with regulatory Environmental Quality Standards. The highest residue concentrations and risks for primary producers were recorded for diuron and Irgarol 1051 in Arzal reservoir, close to a marina. Diuron was present during almost the all survey periods, whereas Irgarol 1051 exhibited a clear seasonal pattern, with highest concentrations recorded in June and July. These results suggest that the use of antifouling biocides is responsible for a major part of the contamination of the lower part of the Vilaine River course for Irgarol 1051. For diuron, agricultural sources may also be involved. The presence of isoproturon and chloroacetanilide herbicides on some dates indicated a significant contribution of the use of plant protection products in

  20. Functional trait responses to sediment deposition reduce macrofauna-mediated ecosystem functioning in an estuarine mudflat

    Science.gov (United States)

    Mestdagh, Sebastiaan; Bagaço, Leila; Braeckman, Ulrike; Ysebaert, Tom; De Smet, Bart; Moens, Tom; Van Colen, Carl

    2018-05-01

    Human activities, among which dredging and land use change in river basins, are altering estuarine ecosystems. These activities may result in changes in sedimentary processes, affecting biodiversity of sediment macrofauna. As macrofauna controls sediment chemistry and fluxes of energy and matter between water column and sediment, changes in the structure of macrobenthic communities could affect the functioning of an entire ecosystem. We assessed the impact of sediment deposition on intertidal macrobenthic communities and on rates of an important ecosystem function, i.e. sediment community oxygen consumption (SCOC). An experiment was performed with undisturbed sediment samples from the Scheldt river estuary (SW Netherlands). The samples were subjected to four sedimentation regimes: one control and three with a deposited sediment layer of 1, 2 or 5 cm. Oxygen consumption was measured during incubation at ambient temperature. Luminophores applied at the surface, and a seawater-bromide mixture, served as tracers for bioturbation and bio-irrigation, respectively. After incubation, the macrofauna was extracted, identified, and counted and then classified into functional groups based on motility and sediment reworking capacity. Total macrofaunal densities dropped already under the thinnest deposits. The most affected fauna were surficial and low-motility animals, occurring at high densities in the control. Their mortality resulted in a drop in SCOC, which decreased steadily with increasing deposit thickness, while bio-irrigation and bioturbation activity showed increases in the lower sediment deposition regimes but decreases in the more extreme treatments. The initial increased activity likely counteracted the effects of the drop in low-motility, surficial fauna densities, resulting in a steady rather than sudden fall in oxygen consumption. We conclude that the functional identity in terms of motility and sediment reworking can be crucial in our understanding of the

  1. Functional trait responses to sediment deposition reduce macrofauna-mediated ecosystem functioning in an estuarine mudflat

    Directory of Open Access Journals (Sweden)

    S. Mestdagh

    2018-05-01

    Full Text Available Human activities, among which dredging and land use change in river basins, are altering estuarine ecosystems. These activities may result in changes in sedimentary processes, affecting biodiversity of sediment macrofauna. As macrofauna controls sediment chemistry and fluxes of energy and matter between water column and sediment, changes in the structure of macrobenthic communities could affect the functioning of an entire ecosystem. We assessed the impact of sediment deposition on intertidal macrobenthic communities and on rates of an important ecosystem function, i.e. sediment community oxygen consumption (SCOC. An experiment was performed with undisturbed sediment samples from the Scheldt river estuary (SW Netherlands. The samples were subjected to four sedimentation regimes: one control and three with a deposited sediment layer of 1, 2 or 5 cm. Oxygen consumption was measured during incubation at ambient temperature. Luminophores applied at the surface, and a seawater–bromide mixture, served as tracers for bioturbation and bio-irrigation, respectively. After incubation, the macrofauna was extracted, identified, and counted and then classified into functional groups based on motility and sediment reworking capacity. Total macrofaunal densities dropped already under the thinnest deposits. The most affected fauna were surficial and low-motility animals, occurring at high densities in the control. Their mortality resulted in a drop in SCOC, which decreased steadily with increasing deposit thickness, while bio-irrigation and bioturbation activity showed increases in the lower sediment deposition regimes but decreases in the more extreme treatments. The initial increased activity likely counteracted the effects of the drop in low-motility, surficial fauna densities, resulting in a steady rather than sudden fall in oxygen consumption. We conclude that the functional identity in terms of motility and sediment reworking can be crucial in our

  2. Status of the population structure of the mangrove crab Ucides cordatus (Decapoda: Ocypodidae) on the Piraquê-açu River estuary, Espírito Santo, Brazil

    OpenAIRE

    Conti, Rita de Cássia; Nalesso, Rosebel Cunha

    2010-01-01

    The land crab Ucides cordatus is a keystone species of neotropical mangrove forests and an important resource of the artisanal fisheries. The spatial and temporal distribution of U. cordatus in the mangrove area of the Piraquê-açu river estuary was determined following a longitudinal estuarine salinity gradient (lower, middle, upper estuary) and along the vertical intertidal gradient. The numbers of open and closed burrows were counted monthly on fixed transects, the inhabiting crabs were cau...

  3. Trophic Dynamics of Filter Feeding Bivalves in the Yangtze Estuarine Intertidal Marsh: Stable Isotope and Fatty Acid Analyses

    Science.gov (United States)

    Wang, Sikai; Jin, Binsong; Qin, Haiming; Sheng, Qiang; Wu, Jihua

    2015-01-01

    Benthic bivalves are important links between primary production and consumers, and are essential intermediates in the flow of energy through estuarine systems. However, information on the diet of filter feeding bivalves in estuarine ecosystems is uncertain, as estuarine waters contain particulate matter from a range of sources and as bivalves are opportunistic feeders. We surveyed bivalves at different distances from the creek mouth at the Yangtze estuarine marsh in winter and summer, and analyzed trophic dynamics using stable isotope (SI) and fatty acid (FA) techniques. Different bivalve species had different spatial distributions in the estuary. Glauconome chinensis mainly occurred in marshes near the creek mouth, while Sinonovacula constricta preferred the creek. Differences were found in the diets of different species. S. constricta consumed more diatoms and bacteria than G. chinensis, while G. chinensis assimilated more macrophyte material. FA markers showed that plants contributed the most (38.86 ± 4.25%) to particular organic matter (POM) in summer, while diatoms contributed the most (12.68 ± 1.17%) during winter. Diatoms made the largest contribution to the diet of S. constricta in both summer (24.73 ± 0.44%) and winter (25.51 ± 0.59%), and plants contributed no more than 4%. This inconsistency indicates seasonal changes in food availability and the active feeding habits of the bivalve. Similar FA profiles for S. constricta indicated that the bivalve had a similar diet composition at different sites, while different δ13C results suggested the diet was derived from different carbon sources (C4 plant Spartina alterniflora and C3 plant Phragmites australis and Scirpus mariqueter) at different sites. Species-specific and temporal and/or spatial variability in bivalve feeding may affect their ecological functions in intertidal marshes, which should be considered in the study of food webs and material flows in estuarine ecosystems. PMID:26261984

  4. Genetic architecture of evolved tolerance to PCBs in the estuarine fish Fundulus heteroclitus

    Science.gov (United States)

    Populations of Atlantic killifish (F. heteroclitus) resident to coastal estuarine habitats contaminated with halogenated aromatic hydrocarbons (HAHs) exhibit heritable resistance to the early life-stage toxicity associated with these compounds. Beyond our knowledge of the aryl hy...

  5. Food and habitat resource partitioning between three estuarine fish species on the Swedish west coast

    Science.gov (United States)

    Thorman, Staffan

    1983-12-01

    In 1978 the food and habitat resource partitioning of three small and common fish species, viz. Pomatoschistus microps (Krøyer), Gasterosteus aculeatus (L.) and Pungitius pungitius (L.) were studied in river Broälven estuary on the Swedish west coast (58°22'N, 11°29'E). The area was divided into three habitats, based on environmental features. In July, September, and October stomach contents and size distribution of each species present were analysed. In July there was high food and habitat overlap between the species. Interference interactions probably occurred between some size classes of P. microps and the other two species. P. pungitius was exposed to both intra- and interspecific interactions. In September the food and habitat overlaps between G. aculeatus and P. pungitius were high, while both had low food and habitat overlaps in relation to P. microps. Interactions between G. aculeatus and P. pungitius were probably influenced by more severe abiotic conditions in one habitat, which caused lower abundances there, and higher abundances in the other two habitats. In October no interactions were observed. These results indicate that competition for food at least temporarily determines the species distribution in a temperate estuary, and that estuarine fish populations are sometimes food limited.

  6. Evidence of estuarine nursery origin of five coastal fish species along the Portuguese coast through otolith elemental fingerprints

    Science.gov (United States)

    Vasconcelos, Rita P.; Reis-Santos, Patrick; Tanner, Susanne; Maia, Anabela; Latkoczy, Christopher; Günther, Detlef; Costa, Maria José; Cabral, Henrique

    2008-08-01

    Connectivity is a critical property of marine populations, particularly for species with segregated juvenile and adult habitats. Knowledge of this link is fundamental in understanding population structure and dynamics. Young adults of commercially important fish species Solea solea, Solea senegalensis, Platichthys flesus, Diplodus vulgaris and Dicentrarchus labrax were sampled off the Portuguese coast in order to establish preliminary evidence of estuarine nursery origins through otolith elemental fingerprints. Concentrations of Li, Na, Mg, K, Mn, Cu, Zn, Sr, Ba and Pb in the otolith section corresponding to juvenile's nursery life period were determined through laser ablation inductively coupled plasma mass spectrometry. Element: Ca ratios in coastal fish differed significantly amongst collection areas, except for Platichthys flesus, and were compared with the elemental fingerprints previously defined for age 0 juveniles in the main estuarine nurseries of the Portuguese coast. Identification of nursery estuaries was achieved for four of the species. Assigned nursery origins varied amongst species and differences in the spatial scale of fish dispersal were also found. Diplodus vulgaris was not reliably assigned to any of the defined nurseries. Overall, results give evidence of the applicability of estuarine habitat tags in future assessments of estuarine nursery role. Research developments on the links between juvenile and adult habitats should contribute for the integrated management and conservation of nurseries and coastal stocks.

  7. Field studies of estuarine turbidity under different freshwater flow conditions, Kaipara River, New Zealand

    Science.gov (United States)

    Mitchell, Steven B.; Green, Malcolm O.; MacDonald, Iain T.; Pritchard, Mark

    2017-11-01

    We present a first interpretation of three days of measurements made in 2013 from the tidal reaches of the Kaipara River (New Zealand) under both low and high freshwater inputs and a neap tidal cycle. During the first day, we occupied two stations that were approximately 6 km apart in a tidal reach that runs for 25 km from the river mouth to the upstream limit of tidal influence. During the second day, longitudinal surveys were conducted over a distance of 6 km centred on the upstream station. The data reveal a turbidity maximum in the form of a high-concentration 'plug' of suspended mud that was advected downstream on the ebbing tide past the upper (HB) measurement station and which exchanged sediment with the seabed by settling at low slack water and by resuspension in the early flooding tide. The data suggest that fine sediment is transported landwards and trapped in the upper part of the tidal reach under these low-flow conditions. On the third day of measurements we repeated the experiments of the first day but later in the year, for a much higher freshwater flow. This interpretation of our data set highlights the potential contribution of a range of processes to the generation of the observed suspended-sediment signals, including resuspension of local bed sediment, advection by the tidal current, settling of suspended sediment over a long timescale compared to the advection timescale, advection of longitudinal gradients in suspended sediment, and suppression of vertical mixing by density stratification of the water column. The level of temporal and spatial detail afforded by these measurements allows a much clearer understanding of the timing and importance of vertical stratification on the transport of suspended particulate matter than is generally possible using fixed-point sensors.

  8. Turbine Sound May Influence the Metamorphosis Behaviour of Estuarine Crab Megalopae

    Science.gov (United States)

    Pine, Matthew K.; Jeffs, Andrew G.; Radford, Craig A.

    2012-01-01

    It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the potential environmental impacts. This study investigated how the sound emitted from an underwater tidal turbine and an offshore wind turbine would influence the settlement and metamorphosis of the pelagic larvae of estuarine brachyuran crabs which are ubiquitous in most coastal habitats. In a laboratory experiment the median time to metamorphosis (TTM) for the megalopae of the crabs Austrohelice crassa and Hemigrapsus crenulatus was significantly increased by at least 18 h when exposed to either tidal turbine or sea-based wind turbine sound, compared to silent control treatments. Contrastingly, when either species were subjected to natural habitat sound, observed median TTM decreased by approximately 21–31% compared to silent control treatments, 38–47% compared to tidal turbine sound treatments, and 46–60% compared to wind turbine sound treatments. A lack of difference in median TTM in A. crassa between two different source levels of tidal turbine sound suggests the frequency composition of turbine sound is more relevant in explaining such responses rather than sound intensity. These results show that estuarine mudflat sound mediates natural metamorphosis behaviour in two common species of estuarine crabs, and that exposure to continuous turbine sound interferes with this natural process. These results raise concerns about the potential ecological impacts of sound generated by renewable energy generation systems placed in the nearshore environment. PMID:23240063

  9. Potential geographic distribution of atmospheric nitrogen deposition from intensive livestock production in North Carolina, USA

    International Nuclear Information System (INIS)

    Costanza, Jennifer K.; Marcinko, Sarah E.; Goewert, Ann E.; Mitchell, Charles E.

    2008-01-01

    To examine the consequences of increased spatial aggregation of livestock production facilities, we estimated the annual production of nitrogen in livestock waste in North Carolina, USA, and analyzed the potential distribution of atmospheric nitrogen deposition from confined animal feeding operations ('CAFO') lagoons. North Carolina is a national center for industrial livestock production. Livestock is increasingly being raised in CAFOs, where waste is frequently held, essentially untreated, in open-air lagoons. Reduced nitrogen in lagoons is volatilized as ammonia (NH 3 ), transported atmospherically, and deposited to other ecosystems. The Albemarle-Pamlico Sound, NC, is representative of nitrogen-sensitive coastal waters, and is a major component of the second largest estuarine complex in the U.S. We used GIS to model the area of water in the Sound within deposition range of CAFOs. We also evaluated the number of lagoons within deposition range of each 1 km 2 grid cell of the state. We considered multiple scenarios of atmospheric transport by varying distance and directionality. Modeled nitrogen deposition rates were particularly elevated for the Coastal Plain. This pattern matches empirical data, suggesting that observed regional patterns of reduced nitrogen deposition can be largely explained by two factors: limited atmospheric transport distance, and spatial aggregation of CAFOs. Under our medium-distance scenario, a small portion (roughly 22%) of livestock production facilities contributes disproportionately to atmospheric deposition of nitrogen to the Albemarle-Pamlico Sound. Furthermore, we estimated that between 14-37% of the state receives 50% of the state's atmospheric nitrogen deposition from CAFO lagoons. The estimated total emission from livestock is 134,000 t NH 3 yr -1 , 73% of which originates from the Coastal Plain. Stronger waste management and emission standards for CAFOs, particularly those on the Coastal Plain nearest to sensitive water bodies

  10. Tidal effects on net ecosystem exchange of carbon in an estuarine wetland

    Science.gov (United States)

    H. Guo; A. Noormets; B. Zhao; J. Chen; G. Sun; Y. Gu; B. Li; J. Chen

    2009-01-01

    One year of continuous data from two eddy-flux towers established along an elevation gradient incoastal Shanghai was analyzed to evaluate the tidal effect on carbon flux (Fc) over an estuarine wetland.The measured wavelet spectra and cospectra of Fc and other environmental factors demonstrated thatthe...

  11. Morphodynamics and Sediment Transport on the Huanghe (Yellow River) Delta: Work in Progress

    Science.gov (United States)

    Kineke, G. C.; Calson, B.; Chadwick, A. J.; Chen, L.; Hobbs, B. F.; Kumpf, L. L.; Lamb, M. P.; Ma, H.; Moodie, A. J.; Mullane, M.; Naito, K.; Nittrouer, J. A.; Parker, G.

    2017-12-01

    Deltas are perhaps the most dynamic of coastal landforms with competing processes that deliver and disperse sediment. As part of the NSF Coastal SEES program, an interdisciplinary team of scientists from the US and China are investigating processes that link river and coastal sediment transport responsible for morphodynamic change of the Huanghe delta- an excellent study site due to its high sediment load and long history of natural and engineered avulsions, that is, abrupt shifts in the river course. A fundamental component of the study is a better understanding of sediment transport physics in a river system that transports mostly silt. Through theory and data analysis, we find that fine-grained rivers fail to develop full scale dunes, which results in faster water flow and substantially larger sediment fluxes as compared to sandy rivers (e.g. the Mississippi River). We also have developed new models for sediment-size dependent entrainment that are needed to make longer term predictions of river sedimentation patterns. On the delta front, we are monitoring the high sediment flux to the coast, which results in steep foresets and ideal conditions for off-shore sediment delivery via gravity flows. These constraints on sediment transport are being used to develop new theory for where and when rivers avulse - including the effects of variable flood discharge, sediment supply, and sea level rise -and how deltas ultimately grow through repeated cycles of lobe development. Flume experiments and field observations are being used to test these models, both in the main channel of the Huanghe and in channels abandoned after historic avulsions. Abandoned channels and floodplains are now dominated by coastal sediment transport through a combination of wave resuspension and tidal transport, settling lag and reverse estuarine circulation. Finally, the field and laboratory tested numerical models are being used as inputs to define a cost curve for efficient avulsion management of

  12. Assessment of acid leachable trace metals in sediment cores from River Uppanar, Cuddalore, Southeast coast of India

    International Nuclear Information System (INIS)

    Ayyamperumal, T.; Jonathan, M.P.; Srinivasalu, S.; Armstrong-Altrin, J.S.; Ram-Mohan, V.

    2006-01-01

    An acid leachable technique is employed in core samples (C1, C2 and C3) to develop a baseline data on the sediment quality for trace metals of River Uppanar, Cuddalore, southeast coast of India. Acid leachable metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn and Cd) indicate peak values at the sulphidic phase and enrichment of metals in the surface layers are due to the anthropogenic activities. Association of trace metals with Fe, Mn indicates their adsorption onto Fe-Mn oxyhydroxides and their correlation with S indicate that they are precipitated as metal sulphides. Factor analysis identified three possible types of geochemical associations and the supremacy of trace metals along with Fe, Mn, S and mud supports their geochemical associations. Factor analysis also signifies that anthropogenic activities have affected both the estuarine and fresh water regions of River Uppanar. - Both natural and anthropogenic factors are affecting metals in sediments

  13. Ecosystem responses to extreme natural events: impacts of three sequential hurricanes in fall 1999 on sediment quality and condition of benthic fauna in the Neuse River Estuary, North Carolina.

    Science.gov (United States)

    Balthis, W Leonard; Hyland, Jeffrey L; Bearden, Daniel W

    2006-08-01

    A study was conducted in November 1999 to assess sediment quality and condition of benthic fauna in the Neuse River Estuary (NRE), North Carolina, USA, following the passage of three Atlantic hurricanes during the two months prior. Samples for analysis of macroinfauna (>0.5 mm sieve size), chemical contamination of sediments, and other abiotic environmental variables (salinity, dissolved oxygen, pH, depth, sediment granulometry) were collected at 20 sites from the mouth of the Neuse River at Pamlico Sound to approximately 90 km upstream. Results were compared to those obtained from the same area in July 1998 using similar protocols. Depressed salinity, caused by extreme rainfall and associated high freshwater flow, persisted throughout much of the estuary, which had experienced periods of water-column stratification and hypoxia of underlying waters. Fifteen of the 20 sites, representing 299 km2 (76% of the survey area), also showed signs of benthic stress based on a multi-metric benthic index of biotic integrity (B-IBI). Benthic impacts included reductions in the abundance, diversity, and numbers of species and shifts in taxonomic composition, with a notable increase in dominance of the opportunistic polychaete Mediomastus ambiseta as other former dominant species declined. There was no significant increase in the extent of chemical contamination compared to pre-hurricane conditions. Storm-related reductions in dissolved oxygen and salinity were the more likely causes of the observed benthic impacts, though it was not possible, based on these results, to separate storm effects from seasonal changes in the benthos and annual episodes of summer anoxia and hypoxia.

  14. Species composition, abundance and distribution of hydromedusae from Dharamtar estuarine system, adjoining Bombay Harbour

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.; Tiwari, L.R.; Nair, V.R.

    Species composition, abundance and distribution of hydromedusae from Dharamtar estuarine system, adjoining Bombay Harbour, Maharashtra, India were investigated during 1984-1985. Twenty six species belonging to 19 genera were obtained from this area...

  15. Estuarine Living Marine Resources: Gulf of Mexico Regional Distribution and Abundance (NCEI Accession 0163993)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is the original (1992) Gulf of Mexico regional component of NOAA's Estuarine Living Marine Resources (ELMR) Project, a national database of ecologically and...

  16. Three-dimensional semi-idealized model for estuarine turbidity maxima in tidally dominated estuaries

    NARCIS (Netherlands)

    Kumar, Mohit; Schuttelaars, Henk M.; Roos, Pieter C.

    2017-01-01

    We develop a three-dimensional idealized model that is specifically aimed at gaining insight in the physical mechanisms resulting in the formation of estuarine turbidity maxima in tidally dominated estuaries. First, the three-dimensional equations for water motion and suspended sediment

  17. Utilization of organic matter by invertebrates along an estuarine gradient in an intermittently open estuary

    Science.gov (United States)

    Lautenschlager, Agnes D.; Matthews, Ty G.; Quinn, Gerry P.

    2014-08-01

    In intermittently open estuaries, the sources of organic matter sustaining benthic invertebrates are likely to vary seasonally, particularly between periods of connection and disconnection with the ocean and higher and lower freshwater flows. This study investigated the contribution of allochthonous and autochthonous primary production to the diet of representative invertebrate species using stable isotope analysis (SIA) during the austral summer and winter (2008, 2009) in an intermittently open estuary on the south-eastern coast of Australia. As the study was conducted towards the end of a prolonged period of drought, a reduced influence of freshwater/terrestrial organic matter was expected. Sampling was conducted along an estuarine gradient, including upper, middle and lower reaches and showed that the majority of assimilated organic matter was derived from autochthonous estuarine food sources. Additionally, there was an input of allochthonous organic matter, which varied along the length of the estuary, indicated by distinct longitudinal trends in carbon and nitrogen stable isotope signatures along the estuarine gradient. Marine seaweed contributed to invertebrate diets in the lower reaches of the estuary, while freshwater/terrestrial organic matter had increased influence in the upper reaches. Suspension-feeding invertebrates derived large parts of their diet from freshwater/terrestrial material, despite flows being greatly reduced in comparison with non-drought years.

  18. Inputs and distributions of synthetic musk fragrances in an estuarine and coastal environment; a case study

    International Nuclear Information System (INIS)

    Sumner, Nicola R.; Guitart, Carlos; Fuentes, Gustavo; Readman, James W.

    2010-01-01

    Synthetic musks are ubiquitous contaminants in the environment. Compartmental distributions (dissolved, suspended particle associated and sedimentary) of the compounds throughout an axial estuarine transect and in coastal waters are reported. High concentrations of Galaxolide (HHCB) and Tonalide (AHTN) (987-2098 ng/L and 55-159 ng/L, respectively) were encountered in final effluent samples from sewage treatment plants (STPs) discharging into the Tamar and Plym Estuaries (UK), with lower concentrations of Celestolide (ADBI) (4-13 ng/L), Phantolide (AHMI) (6-9 ng/L), musk xylene (MX) (4-7 ng/L) and musk ketone (MK) (18-30 ng/L). Rapid dilution from the outfalls is demonstrated with resulting concentrations of HHCB spanning from 5 to 30 ng/L and those for AHTN from 3 to 15 ng/L. The other musks were generally not detected in the estuarine and coastal waters. The suspended particulate matter (SPM) and sedimentary profiles and compositions (HHCB:AHTN ratios) generally reflect the distribution in the water column with highest concentrations adjacent to sewage outfalls. - Synthetic musks were determined in coastal environmental compartments along an estuarine transect indicating their ubiquitous occurrence in transitional waters.

  19. Inputs and distributions of synthetic musk fragrances in an estuarine and coastal environment; a case study

    Energy Technology Data Exchange (ETDEWEB)

    Sumner, Nicola R. [School of Earth, Ocean and Environmental Science, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH (United Kingdom); Guitart, Carlos, E-mail: guitart.carlos@gmail.co [Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH (United Kingdom); Fuentes, Gustavo [Instituto Universitario de Tecnologia del Mar (IUTEMAR), Fundacion La Salle de Ciencias Naturales, Margarita Island (Venezuela, Bolivarian Republic of); Readman, James W. [Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH (United Kingdom)

    2010-01-15

    Synthetic musks are ubiquitous contaminants in the environment. Compartmental distributions (dissolved, suspended particle associated and sedimentary) of the compounds throughout an axial estuarine transect and in coastal waters are reported. High concentrations of Galaxolide (HHCB) and Tonalide (AHTN) (987-2098 ng/L and 55-159 ng/L, respectively) were encountered in final effluent samples from sewage treatment plants (STPs) discharging into the Tamar and Plym Estuaries (UK), with lower concentrations of Celestolide (ADBI) (4-13 ng/L), Phantolide (AHMI) (6-9 ng/L), musk xylene (MX) (4-7 ng/L) and musk ketone (MK) (18-30 ng/L). Rapid dilution from the outfalls is demonstrated with resulting concentrations of HHCB spanning from 5 to 30 ng/L and those for AHTN from 3 to 15 ng/L. The other musks were generally not detected in the estuarine and coastal waters. The suspended particulate matter (SPM) and sedimentary profiles and compositions (HHCB:AHTN ratios) generally reflect the distribution in the water column with highest concentrations adjacent to sewage outfalls. - Synthetic musks were determined in coastal environmental compartments along an estuarine transect indicating their ubiquitous occurrence in transitional waters.

  20. Isolation of heterotrophic diazotrophic bacteria from estuarine surface waters.

    Science.gov (United States)

    Farnelid, Hanna; Harder, Jens; Bentzon-Tilia, Mikkel; Riemann, Lasse

    2014-10-01

    The wide distribution of diverse nitrogenase (nifH) genes affiliated with those of heterotrophic bacteria in marine and estuarine waters indicates ubiquity and an ecologically relevant role for heterotrophic N2 -fixers (diazotrophs) in aquatic nitrogen (N) cycling. However, the lack of cultivated representatives currently precludes an evaluation of their N2 -fixing capacity. In this study, microoxic or anoxic N-free media were inoculated with estuarine Baltic Sea surface water to select for N2 -fixers. After visible growth and isolation of single colonies on oxic plates or in anoxic agar tubes, nifH gene amplicons were obtained from 64 strains and nitrogenase activity, applying the acetylene reduction assay, was confirmed for 40 strains. Two strains, one Gammaproteobacterium affiliated with Pseudomonas and one Alphaproteobacterium affiliated with Rhodopseudomonas were shown to represent established members of the indigenous diazotrophic community in the Baltic Sea, with abundances of up to 7.9 × 10(4) and 4.7 × 10(4)  nifH copies l(-1) respectively. This study reports media for successful isolation of heterotrophic diazotrophs. The applied methodology and the obtained strains will facilitate future identification of factors controlling heterotrophic diazotrophic activity in aquatic environments, which is a prerequisite for understanding and evaluating their ecology and contribution to N cycling at local and regional scales. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  1. Geochronology of the Rio Formoso estuarine by 210Pb

    International Nuclear Information System (INIS)

    Arruda, Gilberto N.; Lyra, Denilson T.; Melo, Julyanne T.B.; Farias, Emerson E.G.; Franca, Elvis J.; Santos, Thiago O.; Souza Neto, Joao A.

    2015-01-01

    Uranium series disequilibrium is useful for dating methods, in which profile sediments can be considered as historical records of anthropogenic events regarding the distribution and impacts of chemical substances on the environment. In this study, 2 deep sediment profiles (about 1 m) were collected, layered at each 3 cm, oven-dried and homogenized. The radiochemical separation of 210 Pb consisted of using hydrobromic acid and an ion exchange resin (DOWEX) for precipitating 210 Pb in the form of lead chromate. After 10 days, the radioactivity was therefore measured by means of the low level gas flow proportional counter, model S5-XLB, from Canberra. Sedimentation rate were obtained by CIC (Constant Initial Concentration) model assumes a constant sedimentation rate throughout the period over which unsupported 210 Pb is measurable. Some sediment profiles were not dated since the percentage of sand was quite high in top layers or a high percentage of organic matter and water in excess were observed in the all sediment samples. 210 Pb geochronology was successfully applied to age nine sediment profiles, in which higher sedimentation rates were observed in the middle portion of the estuarine probably related to shrimp farming impacts. By using geochronology, the detection of human impacts on chemical element distribution could be enhanced in the case of environmental monitoring studies in the Rio Formoso estuarine. (author)

  2. How functional traits of estuarine macrobenthic assemblages respond to metal contamination?

    KAUST Repository

    Piló, D.

    2016-08-06

    The effects of metal contamination on estuarine macrobenthic communities were investigated using the Biological Traits Analysis (BTA). The study was carried out in the Tagus estuary (western Portugal). Samples of macrobenthic communities and associated environmental variables were taken in four surveys (September 2012, and February, May and October 2013) across the contamination gradient from three main zones: a slightly contaminated, a moderately contaminated and a highly contaminated zone. Functional traits for the most abundant species were assigned using seven categories based on “Feeding mode”, “Life span”, “Body size”, “Motility”, “Position in sediments”, “Larval type” and “AMBI ecological group”. To investigate whether the macroinvertebrate community structure was associated with the environmental parameters and biological traits an integrative multivariate analysis, combining the RLQ analysis and the fourth-corner method, was applied. Within this analysis, human-induced estuarine variables (metals) were rendered independent from natural ones (sediment fine particles) through partial correlations. Following this approach, it was possible to decouple the effects of two typically highly correlated environmental descriptors with different origins. Overall, the study identified significant relationships between sediment environmental descriptors and the functional traits of macrobenthic communities. Further, RLQ/Fourth-corner combined analysis successfully isolated the traits and corresponding species that were most correlated with the measured concentration of trace metals in sediments, supporting the knowledge that benthic organisms exhibit distinct responses to different levels of disturbance. A shift in species dominance occurred along the contamination gradient with epifaunal tolerant species with very small size, long life span, and crawling motility dominating the highest contaminated area. This area was also related with

  3. Pigment specific in vivo light absorption of phytoplankton from estuarine, coastal and oceanic waters

    DEFF Research Database (Denmark)

    Stæhr, A.; Markager, S.; Sand-Jensen, K.

    2004-01-01

    The influence of phytoplankton photoacclimation and adaptation to natural growth conditions on the chlorophyll a-specific in vivo absorption coefficient (a* ph) was evaluated for samples collected in estuarine, coastal and oceanic waters. Despite an overall gradient in the physio......-chemical environment from estuaries, over coastal, to oceanic waters, no clear relationships were found between a* ph and the prevailing light, temperature, salinity and nutrient concentrations, indicating that short-term cellular acclimation was of minor importance for the observed variability in a* ph. The clear...... decline in a* ph from oceanic, over coastal, to estuarine waters was, however, strongly correlated with an increase in cell size and intracellular chlorophyll a (chl a) content of the phytoplankton, and a reduction of photosynthetic carotenoids relative to chl a. Variations in photoprotective carotenoids...

  4. Eco-geomorphological Response of an Estuarine Wetland to Changes in the Hydraulic Regime

    Science.gov (United States)

    Howe, A.; Rodrí Guez, J.

    2006-12-01

    In the Hunter Estuary, NSW, Australia, tidal regimes of numerous wetlands have been affected by extensive anthropomorphic intervention, including harbour dredging, land reclamation, and construction of infrastructure. The importance of these wetlands to ecosystem services such as primary productivity, flood attenuation and water quality enhancement has led to an increased effort to rehabilitate degraded sites by reintroduction of tidal flows. Because of the complex and dynamics interactions among hydraulic regime, vegetation and geomorphology, it is difficult to predict how wetlands will respond to the reintroduction of these flows and whether the resulting habitat distribution will achieve desired management outcomes. Eco-geomorphology research conducted at a rehabilitated wetland comprised of mangrove forest and saltmarsh has tracked the response of estuarine vegetation distribution and wetland geomorphology to reinstatement of tidal flows following removal of impediments in 1995. The wetland is an important site for migratory shorebirds and is highly compartmentalized due to the presence of roads and culverts. Our research methodology integrates historical analysis, field measurements and laboratory experiments. Historical analysis matched vegetation evolution obtained from aerial photography to bird roosting habitat use, which is in decline. Field data collection carried out in the last two years included topographic, vegetation and soil surveys; velocity, water quality and water level profiling; and high precision measurements of substrate shallow subsidence and vertical accretion. Laboratory studies focussed on the effects of estuarine vegetation on flow resistance. All this information has allowed for the characterization and conceptualization of the system, which includes zones with different tidal attenuation levels and vegetation distribution. It was found that an increased tidal frame resulting from hydraulic manipulation lead to a landward shift in

  5. Application of sequential leaching, risk indices and multivariate statistics to evaluate heavy metal contamination of estuarine sediments: Dhamara Estuary, East Coast of India.

    Science.gov (United States)

    Asa, Subas Chandra; Rath, Prasanta; Panda, Unmesh Chandra; Parhi, Pankaj Kumar; Bramha, Satyanarayan

    2013-08-01

    In the present study, concentration of some selected trace metals (Fe, Mn, Ni, Co, Pb, Zn, Cu, Cr and Cd) are measured in Brahmani, Baitarani river complex along with Dhamara estuary and its near shore. Chemical partitioning has been made to establish association of metals into different geochemical phases. The exchangeable fraction is having high environmental risk among non-lithogeneous phases due to greater potential for mobility into pore water. The metals with highest bio-availability being Cd, Zn and Cr. The metals like Mn, Zn, Cd and Cu represent an appreciable portion in carbonate phase. Fe-Mn oxides act as efficient scavenger for most of the metals playing a prime role in controlling their fate and transport. Among non-lithogeneous phases apart from reducible, Cr showed a significant enrichment in organic phase. Risk assessment code values indicate that all metals except Fe fall under medium-risk zone. In estuarine zone Cd, Zn, Pb and Cr are released to 32.43, 26.10, 21.81 and 20 %, respectively, indicating their significant bio-availability pose high ecological risk. A quantitative approach has been made through the use of different risk indices like enrichment factor, geo-accumulation index and pollution load index. Factor analysis indicates that in riverine zone, Fe-Mn oxides/hydroxides seem to play an important role in scavenging metals, in estuarine zone, organic precipitation and adsorption to the fine silt and clay particles while in coastal zone, co-precipitation with Fe could be the mechanism for the same. Canonical discriminant function indicates that it is highly successful in discriminating the groups as predicted.

  6. Assessment of reproductive capacity of estuarine plants Butomus umbellatus L. and Alisma plantago-aquatica L. from radioactively contaminated flood plains

    Energy Technology Data Exchange (ETDEWEB)

    Kaneva, A.V.; Majstrenko, T.A.; Rachkova, N.G.; Belykh, E.S.; Zainullin, V.G. [Institute of Biology, Komi Scientific Center, Ural Division of RAS, Syktyvkar, 167982 (Russian Federation)

    2014-07-01

    It is known that the vegetation, along with the climatic conditions and soil type, is one of the key components of terrestrial ecosystems. They are also first to respond to the substrate contamination with radionuclides, metals and organic substances. Biological effects observed in natural plant populations are associated with both presence of mobile compounds of pollutants in abiotic components of the ecosystem and their role in the metabolism of the plant. The goal of the study was to assess the impact of water and sediment contamination with artificial radionuclides and toxic non-radioactive compounds, on the reproductive capacity of estuarial plants using seed germination. Contaminated sites are located in flood plain of the Techa River (Chelabinsk region, Russia) between Muslumovo and Brodokalmak settlements. Radioactive contamination of the territory resulted from increased specific activities of {sup 137}Cs and {sup 90}Sr in water and sediments due to the accidents on the Mayak Production Association. Reference sites were chosen in the flood plains of Brusianka and Sysert' rivers (Sverdlovsk region, Russia). Reference sites are located out of the Eastern Ural Radioactive Trace. Seeds of Butomus umbellatus L. and Alisma plantago-aquatica L., which are common estuarine plant communities in this area, were collected. Specific activities of dose-forming radionuclides in the Techa river water vary from 120 up to 200 mBq/l for {sup 137}Cs and from 26 up to 45 mBq/l for {sup 90}Sr; and in sediments 720-10150 Bq/kg and 600-1500 Bq/kg for {sup 137}Cs and {sup 90}Sr correspondingly. Specific activities of {sup 137}Cs and {sup 90}Sr in water and sediments of both reference rivers do not exceed global fallout levels. B. umbellatus seeds germination was low for plant populations of both reference and contaminated sites. However, a significant (p<0.01) difference was found - the value was higher for reference populations (17.4 ±3.5 %) as compared with the ones from

  7. THE INFLUENCE OF INSECT JUVENILE HORMONE AGONISTTS ON METAMORPHOSIS AND REPRODUCTION IN ESTUARINE CRUSTACEANS

    Science.gov (United States)

    Comparative developmental and reproductive studies were performed on several species of estuarine crustaceans in response to three juvenile hormone agonists (JHAs) (methoprene, fenoxycarb, and pyriproxyfen). Larval development of the grass shrimp, Palaemonetes pugio, was greater ...

  8. Causes of extirpations in the Wadden Sea, an estuarine area in the Netherlands

    NARCIS (Netherlands)

    Wolff, WJ

    The various causes of extirpation of marine and estuarine species were investigated for the Dutch Wadden Sea to gain an impression of their relative importance. I obtained data from geological, archaeological, historical, and biological publications. At least 10 species of algae, 10 invertebrates,

  9. The Biology of Heterotrophic N2-fixing Bacteria in Marine and Estuarine Waters

    DEFF Research Database (Denmark)

    Bentzon-Tilia, Mikkel

    Biological nitrogen (N)2 fixation is of paramount importance for marine N cycling and for life in the oceans in general. It represents the sole mechanism by which microorganisms can channel inert atmospheric N2 gas into biomass and hence it may fuel a significant fraction of primary production...... heterotrophic isolates, this thesis aims at addressing these unknowns. It was found that heterotrophic diazotrophs were present and active in environments previously not associated with N2 fixation e.g. suboxic basins of the Baltic Sea and estuarine surface waters. In these environments they contributed...... with significant amounts fixed N2, suggesting that a reevaluation of the significance of N fixation in suboxic waters and estuarine coastal waters is warranted. It was also documented that heterotrophic diazotrophs could be enriched in culture based on their ability to utilize N2 as the sole N source...

  10. The seasonal factor at the prehistoric site of Shag River Mouth, New Zealand

    International Nuclear Information System (INIS)

    Higham, T.F.G.

    1997-01-01

    This paper addresses moa hunters' seasonality at the Shag River Mouth site. A two meters section in layer 4 of the SM/C: Dune site was left as a baulk in 1988 to enable the stratigraphic profile (∼2m) to be more carefully investigated. Within the baulk, detailed lensing and microstrata could be identified. Claassen (1991) has suggested that one of the most important variables in determining seasonal and prehistoric shell-bearing site formation more accurately is emphasizing finer stratigraphic resolution and more rigorous attention to retrieving midden components. At Shag River Mouth, seven sub-layers, or spits, were excavated within the 2m baulk to refine the precision of subsequent seasonal analyses and enable a detailed assessment of the components of each and their season of deposition. A variety of seasonal methods were utilised including 18 O analysis of blue mussel shell carbonate and growth ring analysis of estuarine bivalves. In addition, sagital otoliths of red cod excavated from the site were sectioned and the annual and seasonal growth rings formed during the fishes' life were analysed for seasonal information. This has enabled a detailed analysis of the seasonality of this discrete area of the Shag River Mouth site. The significance of the results for understanding the prehistoric seasonal round of activities within the site and its wider orbit is presented

  11. Dissolved and colloidal trace elements in the Mississippi River delta outflow after Hurricanes Katrina and Rita

    Science.gov (United States)

    Shim, Moo-Joon; Swarzenski, Peter W.; Shiller, Alan M.

    2012-07-01

    The Mississippi River delta outflow region is periodically disturbed by tropical weather systems including major hurricanes, which can terminate seasonal bottom water hypoxia and cause the resuspension of shelf bottom sediments which could result in the injection of trace elements into the water column. In the summer of 2005, Hurricanes Katrina and Rita passed over the Louisiana Shelf within a month of each other. Three weeks after Rita, we collected water samples in the Mississippi River delta outflow, examining the distributions of trace elements to study the effect of Hurricanes Katrina and Rita. We observed limited stratification on the shelf and bottom waters that were no longer hypoxic. This resulted, for instance, in bottom water dissolved Mn being lower than is typically observed during hypoxia, but with concentrations still compatible with Mn-O2 trends previously reported. Interestingly, for no element were we able to identify an obvious effect of sediment resuspension on its distribution. In general, elemental distributions were compatible with previous observations in the Mississippi outflow system. Co and Re, which have not been reported for this system previously, showed behavior consistent with other systems: input for Co likely from desorption and conservative mixing for Re. For Cs, an element for which there is little information regarding its estuarine behavior, conservative mixing was also observed. Our filtration method, which allowed us to distinguish the dissolved (<0.02 μm) from colloidal (0.02-0.45 μm) phase, revealed significant colloidal fractions for Fe and Zn, only. For Fe, the colloidal phase was the dominant fraction and was rapidly removed at low salinity. Dissolved Fe, in contrast, persisted out to mid-salinities, being removed in a similar fashion to nitrate. This ability to distinguish the smaller Fe (likely dominantly organically complexed) from larger colloidal suspensates may be useful in better interpreting the bioavailablity

  12. Linking Species Traits to the Abiotic Template of Flowing Waters: Contrasting Eco physiologies Underlie Displacement of Zebra Mussels by Quagga Mussels in a Large River-Estuary

    Science.gov (United States)

    Casper, A. F.

    2005-05-01

    The St. Lawrence River-Estuary was the gateway of entry for dreissenids to North America and holds some of the oldest populations. The St. Lawrence also has four distinct physical-chemical water masses (a regional scale abiotic template) that both species inhabit. Despite their ecological similarities, quagga mussels are supplanting zebra mussels in much of their shared range. In order to try to better understand the changing distributions of these two species we compared glycogen, shell mass and tissue biomass in each of the water masses. This comparative physiological combined with experimental approaches (estuarine salinity experiments and reciprocal transplants) showed that while quagga mussels should dominate in most habitats, that abiotic/bioenergetic constraints in two regions (the Ottawa River plume and the freshwater-marine transition zone) might prevent them from dominating these locations. These findings are an example of how the interaction of landscape scale abiotic heterogeneity and a species-specific physiology can have strong impacts of distribution of biota large rivers.

  13. Restoration of Hydrodynamic and Hydrologic Processes in the Chinook River Estuary, Washington ? Feasibility Assessment

    International Nuclear Information System (INIS)

    Khangaonkar, Tarang P.; Breithaupt, Stephen A.; Kristanovich, Felix C.

    2006-01-01

    A hydrodynamic and hydrologic modeling analysis was conducted to evaluate the feasibility of restoring natural estuarine functions and tidal marine wetlands habitat in the Chinook River estuary, located near the mouth of the Columbia River in Washington. The reduction in salmonid populations is attributable primarily to the construction of a Highway 101 overpass across the mouth of the Chinook River in the early 1920s with a tide gate under the overpass. This construction, which was designed to eliminate tidal action in the estuary, has impeded the upstream passage of salmonids. The goal of the Chinook River Restoration Project is to restore tidal functions through the estuary, by removing the tide gate at the mouth of the river, filling drainage ditches, restoring tidal swales, and reforesting riparian areas. The hydrologic model (HEC-HMS) was used to compute Chinook River and tributary inflows for use as input to the hydrodynamic model at the project area boundary. The hydrodynamic model (RMA-10) was used to generate information on water levels, velocities, salinity, and inundation during both normal tides and 100-year storm conditions under existing conditions and under the restoration alternatives. The RMA-10 model was extended well upstream of the normal tidal flats into the watershed domain to correctly simulate flooding and drainage with tidal effects included, using the wetting and drying schemes. The major conclusion of the hydrologic and hydrodynamic modeling study was that restoration of the tidal functions in the Chinook River estuary would be feasible through opening or removal of the tide gate. Implementation of the preferred alternative (removal of the tide gate, restoration of the channel under Hwy 101 to a 200-foot width, and construction of an internal levee inside the project area) would provide the required restorations benefits (inundation, habitat, velocities, and salinity penetration, etc.) and meet flood protection requirements. The

  14. Sources and transformations of anthropogenic nitrogen along an urban river–estuarine continuum

    Directory of Open Access Journals (Sweden)

    M. J. Pennino

    2016-11-01

    Full Text Available Urbanization has altered the fate and transport of anthropogenic nitrogen (N in rivers and estuaries globally. This study evaluates the capacity of an urbanizing river–estuarine continuum to transform N inputs from the world's largest advanced (e.g., phosphorus and biological N removal wastewater treatment facility. Effluent samples and surface water were collected monthly along the Potomac River estuary from Washington D.C. to the Chesapeake Bay over a distance of 150 km. In conjunction with box model mass balances, nitrate stable isotopes and mixing models were used to trace the fate of urban wastewater nitrate. Nitrate concentrations and δ15N-NO3− values were higher down-estuary from the Blue Plains wastewater outfall in Washington D.C. (2.25 ± 0.62 mg L−1 and 25.7 ± 2.9 ‰, respectively compared to upper-estuary concentrations (1.0 ± 0.2 mg L−1 and 9.3 ± 1.4 ‰, respectively. Nitrate concentration then decreased rapidly within 30 km down-estuary (to 0.8 ± 0.2 mg L−1, corresponding to an increase in organic nitrogen and dissolved organic carbon, suggesting biotic uptake and organic transformation. TN loads declined down-estuary (from an annual average of 48 000 ± 5000 kg day−1 at the sewage treatment plant outfall to 23 000 ± 13 000 kg day−1 at the estuary mouth, with the greatest percentage decrease during summer and fall. Annually, there was a 70 ± 31 % loss in wastewater NO3− along the estuary, and 28 ± 6 % of urban wastewater TN inputs were exported to the Chesapeake Bay, with the greatest contribution of wastewater TN loads during the spring. Our results suggest that biological transformations along the urban river–estuary continuum can significantly transform wastewater N inputs from major cities globally, and more work is necessary to evaluate the potential of organic nitrogen and carbon to contribute to eutrophication and hypoxia.

  15. An evaluation of contaminated estuarine sites using sediment quality guidelines and ecological assessment methodologies.

    Science.gov (United States)

    Fulton, M; Key, P; Wirth, E; Leight, A K; Daugomah, J; Bearden, D; Sivertsen, S; Scott, G

    2006-10-01

    Toxic contaminants may enter estuarine ecosystems through a variety of pathways. When sediment contaminant levels become sufficiently high, they may impact resident biota. One approach to predict sediment-associated toxicity in estuarine ecosystems involves the use of sediment quality guidelines (ERMs, ERLs) and site-specific contaminant chemistry while a second approach utilizes site-specific ecological sampling to assess impacts at the population or community level. The goal of this study was to utilize an integrated approach including chemical contaminant analysis, sediment quality guidelines and grass shrimp population monitoring to evaluate the impact of contaminants from industrial sources. Three impacted sites and one reference site were selected for study. Grass shrimp populations were sampled using a push-netting approach. Sediment samples were collected at each site and analyzed for metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides. Contaminant levels were then compared to sediment quality guidelines. In general, grass shrimp population densities at the sites decreased as the ERM quotients increased. Grass shrimp densities were significantly reduced at the impacted site that had an ERM exceedance for chromium and the highest Mean ERM quotient. Regression analysis indicated that sediment chromium concentrations were negatively correlated with grass shrimp density. Grass shrimp size was reduced at two sites with intermediate levels of contamination. These findings support the use of both sediment quality guidelines and site-specific population monitoring to evaluate the impacts of sediment-associated contaminants in estuarine systems.

  16. Historic Habitat Opportunities and Food-Web Linkages of Juvenile Salmon in the Columbia River Estuary and Their Implications for Managing River Flows and Restoring Estuarine Habitat, Physical Sciences Component, Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Jay, David A. [Portland State University

    2009-08-03

    Long-term changes and fluctuations in river flow, water properties, tides, and sediment transport in the Columbia River and its estuary have had a profound effect on Columbia River salmonids and their habitat. Understanding the river-flow, temperature, tidal, and sediment-supply regimes of the Lower Columbia River (LCR) and how they interact with habitat is, therefore, critical to development of system management and restoration strategies. It is also useful to separate management and climate impacts on hydrologic properties and habitat. This contract, part of a larger project led by the National Oceanic and Atmospheric Administration (NOAA), consists of three work elements, one with five tasks. The first work element relates to reconstruction of historic conditions in a broad sense. The second and third elements consist, respectively, of participation in project-wide integration efforts, and reporting. This report focuses on the five tasks within the historic reconstruction work element. It in part satisfies the reporting requirement, and it forms the basis for our participation in the project integration effort. The first task consists of several topics related to historic changes in river stage and tide. Within this task, the chart datum levels of 14 historic bathymetric surveys completed before definition of Columbia River Datum (CRD) were related to CRD, to enable analysis of these surveys by other project scientists. We have also modeled tidal datums and properties (lower low water or LLW, higher high water or HHW, mean water level or MWL, and greater diurnal tidal range or GDTR) as a function of river flow and tidal range at Astoria. These calculations have been carried for 10 year intervals (1940-date) for 21 stations, though most stations have data for only a few time intervals. Longer-term analyses involve the records at Astoria (1925-date) and Vancouver (1902-date). Water levels for any given river flow have decreased substantially (0.3-1.8 m, depending

  17. Ecological periodic tables for nekton and benthic macrofaunal community usage of estuarine habitats Slides

    Science.gov (United States)

    Ecological periodic tables for nekton and benthic macrofaunal community usage of estuarine habitats Steven P. Ferraro, U.S. Environmental Protection Agency, Newport, OR Background/Questions/Methods The chemical periodic table, the Linnaean system of classification, and the Her...

  18. Algal stabilisation of estuarine sediments

    International Nuclear Information System (INIS)

    1992-01-01

    The presence of benthic microalgae can increase the stability of intertidal sediments and influence sediment fluxes within an estuarine environment. Therefore the relative importance of algal stabilisation needs to be understood to help predict the effects of a tidal barrage. The objectives of this study are: to assess the significance of stabilisation of sediments by algae, in relation to the changes in hydrodynamic and sedimentological regimes arising from the construction of tidal power barrages; to identify a reliable and meaningful method of measuring the effectiveness, including duration, of algal binding on sediment stability, and to relate this method to other methods of measuring critical erosion velocity and sediment shear strength; to undertake a series of field experiments investigating the effect of algae on binding sediments and the parameters which could potentially influence such binding and to develop a predictive method for the assessment of sediment stabilisation by algal binding. This report contains plates, figures and tables. (author)

  19. Analysis of the most important river plumes on the Atlantic and Mediterranean Iberian coast by means of satellite imagery

    Directory of Open Access Journals (Sweden)

    Diego Fernandez Novoa

    2014-06-01

    Full Text Available Rivers discharges cause the formation of buoyant plumes in the adjacent coastal area at their mouths, which are characterized by low-salinity water and controlled by outflow inertia, rotation (Coriolis effects, buoyancy, wind, and tide forcing. The turbid plumes influence the adjacent coastal area, since they control the patterns of nutrients, sediments and/or pollutants of fluvial origin on the coastal ocean and can promote strong physical and chemical changes on seawater. These changes affect the biological characteristics of the area, such as primary production, species composition, abundance and distribution of existing microorganism, which demonstrates its high ecological importance. The characterization of the most important river plumes along the Atlantic Iberian coast and the influence of the main forcing drivers (river discharge, wind and tide on them, was carried out through the analysis of plume mean-state images calculated using water leaving radiance data (nLw555 obtained from the MODIS (Moderate Resolution Imaging Spectroradiometer sensor onboard the Aqua satellite during 2003-2013. Satellite data are downloaded from Ocean Color web site (http://oceancolor.gsfc.nasa.gov. Daily high-resolution L1 files from MODIS-Aqua were processed through SeaDAS software. Composite images, interpolated to a regular pixel grid with an approximate resolution of 500m, were built for different synoptic conditions of river discharge, wind regimes and tide, in order to obtain a representative average plume image of each situation and river for the posterior analysis. Results showed that the river discharge is the main forcing factor in the river plume extension. Wind effect is noticeable under high river discharge and tide is important for the estuarine outflow regimes although with some remarkable similarities and differences between the Atlantic rivers due to their intrinsic characteristics.

  20. Uranium geochemistry in estuarine sediments: Controls on removal and release processes

    International Nuclear Information System (INIS)

    Barnes, C.E.; Cochran, J.K.

    1993-01-01

    Porewater uranium profiles from Long Island Sound (LIS) and Amazon shelf sediments and LIS sediment incubation experiments indicate that both removal and release processes control U geochemistry in estuarine sediments. Release of U from sediments occurs in association with Fe reduction. A correlation between U and Fe (and Mn) observed in sediment incubation experiments suggests that there is release of U from Fe-Mn-oxides as they are reduced, consistent with data from the Amazon shelf. In both sediment porewater profiles (LIS and Amazon) and sediment incubation experiments (LIS), there is removal of U from porewater under conditions of sulfate reduction. Sediment incubation experiments indicate that the removal rate is first-order with respect to U concentration, and the rate constant is linearly correlated to sulfate reduction rates. The link between U removal and sulfate reduction (a measure of diagenetic microbial activity) is consistent with a microbial mediation of U reduction. The diffusion flux of U into LIS sediments is estimated from porewater profiles. The inclusion of this estuarine removal term in the oceanic U balance increases the importance of the sediment sink. 62 refs., 12 figs., 2 tabs

  1. Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

    Science.gov (United States)

    Booij, Petra; Sjollema, Sascha B.; van der Geest, Harm G.; Leonards, Pim E. G.; Lamoree, Marja H.; de Voogt, W. Pim; Admiraal, Wim; Laane, Remi W. P. M.; Vethaak, A. Dick

    2015-08-01

    For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and coastal waters are the most productive ecosystems with high primary production by microalgae. The toxic pressure of specific phytotoxic chemicals now poses a major threat to these ecosystems. In a previous study, six herbicides (atrazine, diuron, irgarol, isoproturon, terbutryn and terbutylazine) were identified as the main contaminants affecting photosynthesis in marine microalgae. The purpose of this study is to investigate the toxic pressure of these herbicides in the Dutch estuarine and coastal waters in relation to the effective photosystem II efficiency (ΦPSII) in microalgae. Temporal and spatial variations in the concentrations of these herbicides were analyzed based on monitoring data. Additionally, a field study was carried out in which chemical analysis of water was performed and also a toxicity assessment using the Pulse Amplitude Modulation (PAM) fluorometry assay that measures ΦPSII. The toxic pressure on ΦPSII in microalgae has decreased with 55-82% from 2003 to 2012, with the Western Scheldt estuary showing the highest toxic pressure. By combining toxicity data from the PAM assay with chemical analysis of herbicide concentrations, we have identified diuron and terbutylazine as the main contributors to the toxic pressure on microalgae. Although direct effects are not expected, the toxic pressure is close to the 10% effect level in the PAM assay. A compliance check with the current environmental legislation of the European Union revealed that the quality standards are not sufficient to protect marine microalgae.

  2. Study of Circulation in the Tillamook Bay and the Surrounding Wetland Applying Triple-Nested Models Downscaling from Global Ocean to Estuary

    Science.gov (United States)

    To study the circulation and water quality in the Tillamook Bay, Oregon, a high-resolution estuarine model that covers the shallow bay and the surrounding wetland has been developed. The estuarine circulation at Tillamook Bay is mainly driven by the tides and the river flows and ...

  3. Methylmercury bioaccumulation in an urban estuary: Delaware River USA.

    Science.gov (United States)

    Buckman, Kate; Taylor, Vivien; Broadley, Hannah; Hocking, Daniel; Balcom, Prentiss; Mason, Rob; Nislow, Keith; Chen, Celia

    2017-09-01

    Spatial variation in mercury (Hg) and methylmercury (MeHg) bioaccumulation in urban coastal watersheds reflects complex interactions between Hg sources, land use, and environmental gradients. We examined MeHg concentrations in fauna from the Delaware River estuary, and related these measurements to environmental parameters and human impacts on the waterway. The sampling sites followed a north to south gradient of increasing salinity, decreasing urban influence, and increasing marsh cover. Although mean total Hg in surface sediments (top 4cm) peaked in the urban estuarine turbidity maximum and generally decreased downstream, surface sediment MeHg concentrations showed no spatial patterns consistent with the examined environmental gradients, indicating urban influence on Hg loading to the sediment but not subsequent methylation. Surface water particulate MeHg concentration showed a positive correlation with marsh cover whereas dissolved MeHg concentrations were slightly elevated in the estuarine turbidity maximum region. Spatial patterns of MeHg bioaccumulation in resident fauna varied across taxa. Small fish showed increased MeHg concentrations in the more urban/industrial sites upstream, with concentrations generally decreasing farther downstream. Invertebrates either showed no clear spatial patterns in MeHg concentrations (blue crabs, fiddler crabs) or increasing concentrations further downstream (grass shrimp). Best-supported linear mixed models relating tissue concentration to environmental variables reflected these complex patterns, with species specific model results dominated by random site effects with a combination of particulate MeHg and landscape variables influencing bioaccumulation in some species. The data strengthen accumulating evidence that bioaccumulation in estuaries can be decoupled from sediment MeHg concentration, and that drivers of MeHg production and fate may vary within a small region.

  4. Origin, transport and fate of the dissolved organic matter produced in the watershed of the Paraíba do Sul River, Brazil.

    Science.gov (United States)

    Marques da Silva Junior, Jomar; Soares Gonçalves Serafim, Tassiana; Gomes de Almeida, Marcelo; Dittmar, Thorsten; de Rezende, Carlos Eduardo

    2015-04-01

    The Paraíba do Sul River (PSR) is an important river from Southeastern Brazil that flows through the states of São Paulo, Minas Gerais and Rio de Janeiro. The PSR is responsible for the water supply of over 14 million of the habitants. Due the human occupation and anthropic pressure, only 8% of it is original forest cover remains in the form of small fragmented patches. The remaining of the basin is mostly covered by grasses, such as pasture and sugar cane. Isotopic studies allows the monitoring of ecosystem changes and promotes specific links between ecology, land use and biogeochemical processes. We investigated the isotopic composition of the dissolved organic matter (DOM) in PSR. Our objective was to identify how extensive land use changes, from forest (C3 Plants) to pasture and sugar cane (C4 Plants), have affected river biogeochemistry of organic matter transported by PSR. Water samples were collected at 24 sites along the main channel of the PSR, 14 sites samples at the tributaries and 21 sites samples in the estuarine and marine environmental until 35km of the coast. Sampling was performed in the wet season of the 2013 and the dry season of the 2013. The fluvial and estuarine samples were processed with conventional filtration and the marine samples were processed with the cross-flow filtration. The dissolved organic matter (DOM) was isolated by solid-phase extraction (SPE) with the PPL cartridges (Styrene divinyl benzene polymer). Isotope measurements, organic carbon and nitrogen concentration were performed with a isotope-ratio mass spectrometry (Thermo Finningan). The 13C and the 15N values ranged from -20.0‰ and -29.0‰, and from -0.80 to 4.59 respectively, while the (C/N)a ratio varied between 8 and 41. The 13C were depleted in 13C at the river samples from the wet season, and in the estuary and marine areas as well. The 13C average values observed during the wet season in the PSR and in the estuarine samples are close to those

  5. Modelling Watershed and Estuarine Controls on Salt Marsh Distributions

    Science.gov (United States)

    Yousefi Lalimi, F.; Marani, M.; Murray, A. B.; D'Alpaos, A.

    2017-12-01

    The formation and evolution of tidal platforms have been extensively studied through observations and models, describing landform dynamics as a result of the local interactions and feedbacks among hydrodynamics, vegetation, and sediment transport. However, existing work mainly focuses on individual marsh platforms and, possibly, their immediate surrounding, such that the influence and controls on marsh dynamics of inland areas (through fluvial inputs) and of exchanges with the ocean have not been comprehensively and simultaneously accounted for. Here, we develop and use a process-based model to evaluate the relative role of watershed, estuarine, and ocean controls on salt marsh accretionary and depositional/erosional dynamics and define how these factors interact to determine salt marsh resilience to environmental change at the whole-estuary scale. Our results, in line with previous work, show that no stable equilibrium exists for the erosional dynamics of the marsh/tidal flat boundary. In addition, we find that under some circumstances, vertical accretion/erosion dynamics can lead to transitions between salt marsh and tidal flat equilibrium states that occur much more rapidly than marsh/tidal flat boundary erosion or accretion could. We further define, in the multidimensional space of estuarine-scale morphodynamic forcings, the basins of attractions leading to marsh-dominated and tidal-flat-dominated estuaries. The relatively slow dynamics asymptotically leading to marsh- or tidal-flat- dominance in many cases suggest that estuaries are likely to be found, at any given time, in a transition state dictated by temporal variations in environmental forcings.

  6. Impact of intertidal area characteristics on estuarine tidal hydrodynamics: A modelling study for the Scheldt Estuary

    Science.gov (United States)

    Stark, J.; Smolders, S.; Meire, P.; Temmerman, S.

    2017-11-01

    Marsh restoration projects are nowadays being implemented as ecosystem-based strategies to reduce flood risks and to restore intertidal habitat along estuaries. Changes in estuarine tidal hydrodynamics are expected along with such intertidal area changes. A validated hydrodynamic model of the Scheldt Estuary is used to gain fundamental insights in the role of intertidal area characteristics on tidal hydrodynamics and tidal asymmetry in particular through several geomorphological scenarios in which intertidal area elevation and location along the estuary is varied. Model results indicate that the location of intertidal areas and their storage volume relative to the local tidal prism determine the intensity and reach along the estuary over which tidal hydrodynamics are affected. Our model results also suggest that intertidal storage areas that are located within the main estuarine channel system, and hence are part of the flow-carrying part of the estuary, may affect tidal hydrodynamics differently than intertidal areas that are side-basins of the main estuarine channel, and hence only contribute little to the flow-carrying cross-section of the estuary. If tidal flats contribute to the channel cross-section and exert frictional effects on the tidal propagation, the elevation of intertidal flats influences the magnitude and direction of tidal asymmetry along estuarine channels. Ebb-dominance is most strongly enhanced if tidal flats are around mean sea level or slightly above. Conversely, flood-dominance is enhanced if the tidal flats are situated low in the tidal frame. For intertidal storage areas at specific locations besides the main channel, flood-dominance in the estuary channel peaks in the vicinity of those areas and generally reduces upstream and downstream compared to a reference scenario. Finally, the model results indicate an along-estuary varying impact on the tidal prism as a result of adding intertidal storage at a specific location. In addition to known

  7. Physical biological coupling in the Pearl River Estuary

    Science.gov (United States)

    Harrison, Paul J.; Yin, Kedong; Lee, J. H. W.; Gan, Jianping; Liu, Hongbin

    2008-07-01

    The Pearl River Estuary is a subtropical estuary and the second largest in China based on discharge volume from the Pearl River. Processes in the estuary vary spatially and temporally (wet vs dry season). In the dry season at the head of the estuary, hypoxic and nearly anoxic conditions occur and NH 4 reaches >600 μM, NO 3 is ˜300 μM and nitrite is ˜60 μM indicating that nitrification and denitrification may be important dry season processes in the region extending 40 km upstream of the Humen outlet. There are very few biological studies conducted in this upper section of the estuary in either the dry or wet seasons and hence there is a need for further research in this region of the river. In the wet season, the salinity wedge extends to the Hongqimen outlet and oxygen is low (35-80% saturation). Nitrate is ˜100 μM, silicate ˜140 μM; and phosphate is relatively low at ˜0.5 μM, yielding an N:P ratio up to ˜200:1 in summer. Nutrients decrease in the lower estuary and primary productivity may become potentially P-limited. Eutrophication is not as severe as one would expect from the nutrient inputs from the Pearl River and from Hong Kong's sewage discharge. This estuary shows a remarkable capacity to cope with excessive nutrients. Physical processes such as river discharge, tidal flushing, turbulent dispersion, wind-induced mixing, and estuarine circulation play an important role in controlling the production and accumulation of algal blooms and the potential occurrence of hypoxia. Superimposed on the physical processes of the estuary are the chemical and biological processes involved in the production of the bloom. For example, the 100N:1P ratio indicates that P potentially limits the amount of algal biomass (and potential biological oxygen demand) in summer. While extended periods of hypoxia are rare in Hong Kong waters, episodic events have been reported to occur during late summer due to factors such as low wind, high rainfall and river discharge which

  8. Water organic pollution and eutrophication influence soil microbial processes, increasing soil respiration of estuarine wetlands: site study in jiuduansha wetland.

    Science.gov (United States)

    Zhang, Yue; Wang, Lei; Hu, Yu; Xi, Xuefei; Tang, Yushu; Chen, Jinhai; Fu, Xiaohua; Sun, Ying

    2015-01-01

    Undisturbed natural wetlands are important carbon sinks due to their low soil respiration. When compared with inland alpine wetlands, estuarine wetlands in densely populated areas are subjected to great pressure associated with environmental pollution. However, the effects of water pollution and eutrophication on soil respiration of estuarine and their mechanism have still not been thoroughly investigated. In this study, two representative zones of a tidal wetland located in the upstream and downstream were investigated to determine the effects of water organic pollution and eutrophication on soil respiration of estuarine wetlands and its mechanism. The results showed that eutrophication, which is a result of there being an excess of nutrients including nitrogen and phosphorus, and organic pollutants in the water near Shang shoal located upstream were higher than in downstream Xia shoal. Due to the absorption and interception function of shoals, there to be more nitrogen, phosphorus and organic matter in Shang shoal soil than in Xia shoal. Abundant nitrogen, phosphorus and organic carbon input to soil of Shang shoal promoted reproduction and growth of some highly heterotrophic metabolic microorganisms such as β-Proteobacteria, γ-Proteobacteria and Acidobacteria which is not conducive to carbon sequestration. These results imply that the performance of pollutant interception and purification function of estuarine wetlands may weaken their carbon sequestration function to some extent.

  9. Associated fauna to the mangroves and other marshes in the Delta-estuary of the River Magdalena, Colombia

    International Nuclear Information System (INIS)

    Moreno Bejarano, Luz Myriam; Alvarez Leon, Ricardo

    2003-01-01

    A synthesis of observations and collections of fauna associated with different vegetative communities and bodies of water present in the estuarine-delta of Magdalena river, with emphasis in the Via Park Isla Salamanca (56.200 acres) and National Reserve Flora and Fauna Sanctuary of the Cienaga Grande de Santa Marta (23.000 acres), between 1978-1985. The information was gathered through samplings and manual captures affected during 1978 and period 1981-1985, as well as accomplished direct observations sporadically in the period 1986-1998. The records of 10 species of amphibians, 40 species of reptiles, 194 species of birds and 46 species of mammals show the great variety of fauna in this Caribbean area of Colombia

  10. Lead distribution in coastal and estuarine sediments around India

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, S.; Chakraborty, P.; Nath, B.N.

    . Trace element geochemical associations in the Arabian Gulf. Mar. Pollut. Bull. 17, 353–356. doi:10.1016/0025-326X(86)90247-X Achyuthan, H., Richardmohan, D., Srinivasalu, S., 2002a. Trace metals concentrations in the sediment cores of estuary... in the coastal sediment of chennai coast. IIOAB J. 3, 12–18. Ray, A.K., Tripathy, S.C., Patra, S., Sarma, V. V, 2006. Assessment of Godavari estuarine mangrove ecosystem through trace metal studies. Environ. Int. 32, 219–223. Reddy, M.S., Basha, S., Sravan...

  11. The Importance of Allochthonous Subsidies to an Estuarine Food Web along a Salinity Gradient

    Science.gov (United States)

    Estuarine food webs function within a heterogeneous mosaic and are supported by a mix of primary producers from both local and distant sources. Processes governing the exchange and consumption of organic matter (OM), however, are poorly understood. To study the contribution of ...

  12. Sr isotope evidence for a lacustrine origin for the upper Miocene to Pliocene Bouse Formation, lower Colorado River trough, and implications for timing of Colorado Plateau uplift

    Science.gov (United States)

    Spencer, J.E.; Patchett, P.J.

    1997-01-01

    The upper Miocene to Pliocene Bouse Formation in the lower Colorado River trough, which consists largely of siltstone with basal tufa and marl, has been interpreted as estuarine on the basis of paleontology. This interpretation requires abrupt marine inundation that has been linked to early rifting in the Gulf of California and Salton trough. New strontium isotope measurements reported here from carbonates and invertebrate shells in the Bouse Formation reveal no evidence of marine water, but are consistent with deposition in a lake or chain of lakes fed by the Colorado River. Furthermore, the absence of a southward decrease in 87Sr/86Sr within the Bouse Formation does not support the estuarine model in which low 87Sr/86Sr marine Sr would have dominated the mouth of the hypothetical Bouse estuary. Elevation of originally marine 87Sr/86Sr in the Bouse Formation to its present level, due to postdepositional interaction with ground water, is unlikely because Sr from secondary calcite above, below, and within the Bouse Formation is consistently less radiogenic, not more, than Bouse marl and shells. In contrast to Bouse Sr, strontium from mollusks in tidal-flat and delta-front paleoenvironments in the contemporaneous Imperial Formation in the Salton trough and from the subsurface south of Yuma was derived from sea water and confirms the dominance of marine strontium near or at the mouth of the late Miocene to early Pliocene Colorado River. Inferred post-early Pliocene uplift of the Bouse Formation from below sea level to modern elevations of up to 550 m has been used to support a late Cenozoic uplift age for the nearby Colorado Plateau. This constraint on uplift timing is eliminated if the Bouse Formation is lacustrine.

  13. Effects of mud supply on large-scale estuary morphology and development over centuries to millennia

    NARCIS (Netherlands)

    Braat, L.; van Kessel, Thijs; Leuven, J.R.F.W.; Kleinhans, M.G.

    2017-01-01

    Alluvial river estuaries consist largely of sand but are typically flanked by mudflats and salt marshes. The analogy with meandering rivers that are kept narrower than braided rivers by cohesive floodplain formation raises the question of how large-scale estuarine morphology and the late Holocene

  14. The management of the Diama reservoir (Senegal River)

    Science.gov (United States)

    Duvail, S.; Hamerlynck, O.

    2003-04-01

    The Senegal River is regulated by 2 dams built in the 1980's by the "Organisation pour la Mise en Valeur du fleuve Sénégal" (OMVS), a river basin management organisation grouping Mali, Senegal and Mauritania. The initial objectives of OMVS, which were to regulate the Senegal flows in order to develop irrigated agriculture, produce hydropower and facilitate river navigation has been only partially met. The maintenance of the annual flood by the upstream dam (Manantali), initially to be phased out when irrigated agriculture would have replaced the traditional recession agriculture, is now scheduled to continue indefinitely on the basis of socio-economic and environmental concerns. This change of mindset has however not affected the management of the downstream dam (Diama). Initially conceived as a salt-wedge dam, its function evolved to a reservoir dam with a high and constant water level. During the dry season, the water level is maintained high and constant in order to reduce the pumping costs for the irrigated agriculture in the delta. During the flood season (July-October) the dam is primarily managed for risk avoidance: limit flooding downstream of the dam (especially the city of St. Louis) and secure the infrastructure of the dam itself. The permanent freshwater reservoir lake has adverse effects on ecosystems, on human and animal health and a high social cost for the traditional stakeholders of the deltaic floodplain (fishermen, livestock keepers and gatherers). Upstream of the reservoir there is an excess of stagnant freshwater and managers are confronted with the development of invasive species while substantial downstream flooding is essential for the estuarine ecosystems and local livelihoods. The presentation will review the different approaches to the management of the Diama reservoir and proposes different management scenarios and compares their economical, environmental, and social costs and benefits.

  15. Geochronology of the Rio Formoso estuarine by {sup 210}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Arruda, Gilberto N.; Lyra, Denilson T.; Melo, Julyanne T.B.; Farias, Emerson E.G.; Franca, Elvis J.; Santos, Thiago O., E-mail: gnarruda@cnen.gov.br, E-mail: denilsonengseg@gmail.com, E-mail: julyanne.melo@ufpe.br, E-mail: emersonemiliano@yahoo.com.br, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Souza Neto, Joao A., E-mail: adauto@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2015-07-01

    Uranium series disequilibrium is useful for dating methods, in which profile sediments can be considered as historical records of anthropogenic events regarding the distribution and impacts of chemical substances on the environment. In this study, 2 deep sediment profiles (about 1 m) were collected, layered at each 3 cm, oven-dried and homogenized. The radiochemical separation of {sup 210}Pb consisted of using hydrobromic acid and an ion exchange resin (DOWEX) for precipitating {sup 210}Pb in the form of lead chromate. After 10 days, the radioactivity was therefore measured by means of the low level gas flow proportional counter, model S5-XLB, from Canberra. Sedimentation rate were obtained by CIC (Constant Initial Concentration) model assumes a constant sedimentation rate throughout the period over which unsupported {sup 210}Pb is measurable. Some sediment profiles were not dated since the percentage of sand was quite high in top layers or a high percentage of organic matter and water in excess were observed in the all sediment samples. {sup 210}Pb geochronology was successfully applied to age nine sediment profiles, in which higher sedimentation rates were observed in the middle portion of the estuarine probably related to shrimp farming impacts. By using geochronology, the detection of human impacts on chemical element distribution could be enhanced in the case of environmental monitoring studies in the Rio Formoso estuarine. (author)

  16. Metal Bioaccumulation by Estuarine Food Webs in New England, USA

    Directory of Open Access Journals (Sweden)

    Celia Y. Chen

    2016-06-01

    Full Text Available Evaluating the degree of metal exposure and bioaccumulation in estuarine organisms is important for understanding the fate of metals in estuarine food webs. We investigated the bioaccumulation of Hg, methylmercury (MeHg, Cd, Se, Pb, and As in common intertidal organisms across a watershed urbanization gradient of coastal marsh sites in New England to relate metal exposure and bioaccumulation in fauna to both chemical and ecological factors. In sediments, we measured metal and metalloid concentrations, total organic carbon (TOC and SEM-AVS (Simultaneously extracted metal-acid volatile sulfides. In five different functional feeding groups of biota, we measured metal concentrations and delta 15N and delta 13C signatures. Concentrations of Hg and Se in biota for all sites were always greater than sediment concentrations whereas Pb in biota was always lower. There were positive relationships between biota Hg concentrations and sediment concentrations, and between biota MeHg concentrations and both pelagic feeding mode and trophic level. Bioavailability of all metals measured as SEM-AVS or Benthic-Sediment Accumulation Factor was lower in more contaminated sites, likely due to biogeochemical factors related to higher levels of sulfides and organic carbon in the sediments. Our study demonstrates that for most metals and metalloids, bioaccumulation is metal specific and not directly related to sediment concentrations or measures of bioavailability such as AVS-SEM.

  17. Deformation of textural characteristics and sedimentology along micro-tidal estuarine beaches

    Digital Repository Service at National Institute of Oceanography (India)

    Dora, G.U.; SanilKumar, V.; Philip, C.S.; Johnson, G.

    Indian Journal of Geo Marine Sciences Vol. 45 (11), November 2016, pp. 1432-1444 *Corresponding author Deformation of textural characteristics and sedimentology along micro- tidal estuarine beaches G. Udhaba Dora, V. Sanil Kumar*, C... sediment is a foremost parameter for a coastal researcher/engineer/designer due to its various applications for sorting out a coastal environment. Sedimentary process at foreshore zone is a highly dynamical whereas textural characteristics...

  18. Radium isotope (223Ra, 224Ra, 226Ra and 228Ra) distribution near Brazil's largest port, Paranaguá Bay, Brazil

    International Nuclear Information System (INIS)

    Dias, Thais H.; Oliveira, Joselene de; Sanders, Christian J.; Carvalho, Franciane; Sanders, Luciana M.; Machado, Eunice C.; Sá, Fabian

    2016-01-01

    This work investigates the 223 Ra, 224 Ra, 226 Ra and 228 Ra isotope distribution in river, estuarine waters and sediments of the Paranaguá Estuarine Complex (PEC). The stratification of the Ra isotopes along water columns indicate differing natural sources. In sediments, the radium isotope activities was inversely proportional to the particle size. The highest concentrations of 223 Ra, 224 Ra, 226 Ra and 228 Ra in the water column were found in the bottom more saline waters and towards the inner of the estuary. These relatively high concentrations towards the bottom of the estuary may be attributed to the influence of tidally driven groundwater source and desorption from particles at the maximum turbidity zone. The apparent river water ages from the radium isotope ratios, 223 Ra/ 224 Ra and 223 Ra/ 228 Ra, indicate that the principal rivers that flow into the estuary have residence times from between 6 and 11 days. - Highlights: • Radium isotope concentrations were evaluated along a large estuarine system. • The radioactivity level in river, estuary and sediments was within a normal range. • Spatial distributions of site specific radionuclides have differing activities and sources.

  19. Using high frequency CDOM hyperspectral absorption to fingerprint river water sources

    Science.gov (United States)

    Beckler, J. S.; Kirkpatrick, G. J.; Dixon, L. K.; Milbrandt, E. C.

    2016-12-01

    Quantifying riverine carbon transfer from land to sea is complicated by variability in dissolved organic carbon (DOC), closely-related dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) concentrations, as well as in the composition of the freshwater end members of multiple drainage basins and seasons. Discrete measurements in estuaries have difficulty resolving convoluted upstream watershed dynamics. Optical measurements, however, can provide more continuous data regarding the molecular composition and concentration of the CDOM as it relates to river flow, tidal mixing, and salinity and may be used to fingerprint source waters. For the first time, long-term, hyperspectral CDOM measurements were obtained on filtered Caloosahatchee River estuarine waters using an in situ, long-pathlength spectrophotometric instrument, the Optical Phytoplankton Discriminator (OPD). Through a collaborative monitoring effort among partners within the Gulf of Mexico Coastal Ocean Observing System (GCOOS), ancillary measurements of fluorescent DOM (FDOM) and water quality parameters were also obtained from co-located instrumentation at high frequency. Optical properties demonstrated both short-term (hourly) tidal variations and long-term (daily - weekly) variations corresponding to changes in riverine flow and salinity. The optical properties of the river waters are demonstrated to be a dilution-adjusted linear combination of the optical properties of the source waters comprising the overall composition (e.g. Lake Okeechobee, watershed drainage basins, Gulf of Mexico). Overall, these techniques are promising as a tool to more accurately constrain the carbon flux to the ocean and to predict the optical quality of coastal waters.

  20. Seasonal variations in secondary production of the Mandovi-Zuari estuarine system of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Selvakumar, R.A.; Nair, V.R.; Madhupratap, M.

    . In general, the saline period was more productive (12.9 mg dry wt/m3/day) compared to the low saline period (11 mg dry wt/m3/day). The average secondary production in the estuarine system was 21.4 mg dry wt/m3/day or 1078 tonnes carbon/yr. The coefficient...

  1. RESPONSE OF GHOST SHRIMP (NEOTRYPAEA CALIFORNIENSIS) BIOTURBATION TO ORGANIC MATTER ENRICHMENT OF ESTUARINE INTERTIDAL SEDIMENTS

    Science.gov (United States)

    Populations of burrowing shrimp (Neotrypaea californiensis and Upogebia p;ugettensis) are the dominant invertebrate fauna on Pacific estuarine tide flats, occupying >80% of intertidal area in some estuaries. Burrowing shrimp are renowned for their bioturbation of intertidal sedi...

  2. Air-Seawater Exchange of Organochlorine Pesticides along the Sediment Plume of a Large Contaminated River.

    Science.gov (United States)

    Lin, Tian; Guo, Zhigang; Li, Yuanyuan; Nizzetto, Luca; Ma, Chuanliang; Chen, Yingjun

    2015-05-05

    Gaseous exchange fluxes of organochlorine pesticides (OCPs) across the air-water interface of the coastal East China Sea were determined in order to assess whether the contaminated plume of the Yangtze River could be an important regional source of OCPs to the atmosphere. Hexachlorocyclohexanes (HCHs), chlordane compounds (CHLs), and dichlorodiphenyltrichloroethanes (DDTs) were the most frequently detected OCPs in air and water. Air-water exchange was mainly characterized by net volatilization for all measured OCPs. The net gaseous exchange flux ranged 10-240 ng/(m2·day) for γ-HCH, 60-370 ng/(m2·day) for trans-CHL, 97-410 ng/(m2·day) for cis-CHL, and ∼0 (e.g., equilibrium) to 490 ng/(m2·day) for p,p'-DDE. We found that the plume of the large contaminated river can serve as a significant regional secondary atmospheric source of legacy contaminants released in the catchment. In particular, the sediment plume represented the relevant source of DDT compounds (especially p,p'-DDE) sustaining net degassing when clean air masses from the open ocean reached the plume area. In contrast, a mass balance showed that, for HCHs, contaminated river discharge (water and sediment) plumes were capable of sustaining volatilization throughout the year. These results demonstrate the inconsistencies in the fate of HCHs and DDTs in this large estuarine system with declining primary sources.

  3. Comparative evaluation of effects of ozonated and chlorinated thermal discharges on estuarine and freshwater organisms

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, C.R.; Sugam, R.; Meldrim, J.W.; Holmstrom, E.R.; Balog, G.E.

    1980-08-01

    As a part of a program at PSE and G designed to examine the feasibility of ozonation as an alternative to chlorination for control of biofouling in once-through cooling systems, the biological effects of ozonated and chlorinated thermal discharges were evaluated with estuarine and freshwater organisms. Mortality at salinities between 0.5 to 2.5 ppt with mummichog and white perch indicated greater toxicity for chlorine while the alewife, spottail shiner, rainbow trout and white perch in freshwater were more sensitive to ozone. Behavioral and physograhic results were consistent with those observed in toxicity studies. Initial cough response and avoidance concentrations of mummicog and white perch in estuarine waters were lower when exposed to chlorine than to ozone. In freshwater, blueback herring, alewife, rainbow trout, spottail shiner, banded killifish, and white perch avoided lower concentrations of ozone than chlorine.

  4. BIOTIC (FORAMINIFERA AND THECAMOEBIANS AND ABIOTIC PARAMETERS AS PROXIES FOR IDENTIFICATION OF THE ENVIRONMENTAL HETEROGENEITY IN CAETÉ RIVER ESTUARY, AMAZON COAST, BRAZIL

    Directory of Open Access Journals (Sweden)

    Lazaro Luiz Mattos Laut1

    2016-01-01

    Full Text Available Foraminifera and thecamoebians assemblages were analyzed at Caeté River Estuary in order to identify saline gradients and intensity of human impacts. In the study area, 29 species of foraminifera typically from intertidal environments and 11 species of thecamoebians were identified. The microfaunal assemblages were characterized by low diversity, averaging 1.9 at the mouth and 0.5 near Bragança City. These values are common in transitional coastal environments along de Brazilian Coast. Statistical analysis, based on the relative abundance of species, did not reveal the presence of an estuarine gradient, which was corroborated by the physical and chemical parameters measured in the field. An increasing of sedimentary fine fraction and organic matter occurs in the intermediate region of the estuary, indicating attenuation of the stream influence. The calcareous foraminifera species were associated with high salinity, temperature and pH values. The agglutinated species were associated with muddy sediment, total organic matter and lower salinity. Four environmental compartments were identified based on biotic and abiotic analysis, but they do not represent the classic estuarine gradient, instead, they represent the differences in the freshwater supply and mangrove distance.

  5. Disturbances to metal partitioning during toxicity testing of iron(II)-rich estuarine pore waters and whole sediments.

    Science.gov (United States)

    Simpson, Stuart L; Batley, Graeme E

    2003-02-01

    Metal partitioning is altered when suboxic estuarine sediments containing Fe(II)-rich pore waters are disturbed during collection, preparation, and toxicity testing. Experiments with model Fe(II)-rich pore waters demonstrated the rates at which adsorptive losses of Cd, Cu, Ni, Mn, Pb, and Zn occur upon exposure to air. Experiments with Zn-contaminated estuarine sediments demonstrated large and often unpredictable changes to metal partitioning during sediment storage, removal of organisms, and homogenization before testing. Small modifications to conditions, such as aeration of overlying waters, caused large changes to the metal partitioning. Disturbances caused by sediment collection required many weeks for reestablishment of equilibrium. Bioturbation by benthic organisms led to oxidation of pore-water Fe(II) and lower Zn fluxes because of the formation of Fe hydroxide precipitates that adsorb pore-water Zn. For five weeks after the addition of organisms to sediments, Zn fluxes increased slowly as the organisms established themselves in the sediments, indicating that the establishment of equilibrium was not rapid. The results are discussed in terms of the dynamic nature of suboxic, Fe(II)-rich estuarine sediments, how organisms perturb their environment, and the importance of understanding chemistry in toxicity testing with whole sediments or pore water. Recommendations are provided for the handling of sediments for toxicity testing.

  6. Variation in ultrafiltered and LMW organic matter fluorescence properties under simulated estuarine mixing transects: 1. Mixing alone

    Science.gov (United States)

    Boyd, Thomas J.; Barham, Bethany P.; Hall, Gregory J.; Osburn, Christopher L.

    2010-09-01

    Ultrafiltered and low molecular weight dissolved organic matter (UDOM and LMW-DOM, respectively) fluorescence was studied under simulated estuarine mixing using samples collected from Delaware, Chesapeake, and San Francisco Bays (USA) transects. UDOM was concentrated by tangential flow ultrafiltration (TFF) from the marine (>33 PSU), mid-estuarine (˜16 PSU), and freshwater (ocean members. LMW fluorescence components fit a decreasing linear mixing model from mid salinities to the ocean end-member, but were more highly fluorescent than mixing alone would predict in lower salinities (shifts were also seen in UDOM peak emission wavelengths with blue-shifting toward the ocean end-member. Humic-type components in UDOM generally showed lower fluorescent intensities at low salinities, higher at mid-salinities, and lower again toward the ocean end-member. T (believed to be proteinaceous) and N (labile organic matter) peaks behaved similarly to each other, but not to B peak fluorescence, which showed virtually no variation in permeate or UDOM mixes with salinity. PCA and PARAFAC models showed similar results suggesting trends could be modeled for DOM end- and mid-member sources. Changes in fluorescence properties due to estuarine mixing may be important when using CDOM as a proxy for DOM cycling in coastal systems.

  7. Application of PIXE in pollution control of the Matola River in Mozambique-analysis of fish scales

    Energy Technology Data Exchange (ETDEWEB)

    Guambe, J.F. [Freshwater Research Unit, Department of Zoology, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa); Departamento de Fisica, Universidade Edouardo Mondlane, C.P. 257, Maputo (Mozambique); Materials Research Department, iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); Mars, J.A., E-mail: marsja@cput.ac.za [Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7535 (South Africa); Day, J. [Freshwater Research Unit, Department of Zoology, University of Cape Town, Private Bag, Rondebosch 7701 (South Africa)

    2012-02-15

    Since PIXE is able to distinguish concentrations of elements at very small spatial scales, it can be used for estimating levels of metal pollution in biological material. This paper provides a preliminary report of a pilot study on the use of PIXE for the identification and quantification of elements (Al (3 wt%), Si 0.5 wt%), S (1.5 wt%), Cl (15 ppm), Mn (5 ppm), Fe (50 ppm), Ni (3 ppm), Zn (2 ppm), Rb (2 ppm), Sr (800 ppm) and Se (3 ppm)) in scales of the estuarine fish Pomadasys kaakan caught in the Matola River upstream from the Maputo estuary and, downstream of an aluminium smelter. Concentrations of both aluminium and sulphur were high (3 wt% and 1.5 wt%, respectively).

  8. Characterization of soil salinization in typical estuarine area of the Jiaozhou Bay, China

    Science.gov (United States)

    Li, Qifei; Xi, Min; Wang, Qinggai; Kong, Fanlong; Li, Yue

    2018-02-01

    In this study, the characteristics of soil salinization and the effects of main land use/land cover and other factors in typical estuarine area of the Jiaozhou Bay are investigated. Soil samples were collected in the parallel coastal zone, vertical coastal zone and longitudinal profile depth in the area to determine the soil salt content. The correlation analysis and principal component analysis are used to address the general characteristics of soil salinization in the study area. In the horizontal direction, there are moderate salinization, severe salinization and saline soil state. The farther from the sea (within 1.1 km), the lower the soil salinization degree. In the direction of longitudinal profile depth, there are severe salinization and saline soil state, and the soil salt content is accumulated in the surface and bottom. The Na+ and Cl- are the dominant cation and anion, respectively, the distributions of which are consistent with that of salt content. All the salinization indexes, except for soil pH, are of moderate/strong variability. The invasion of Spartina alterniflora results in the increase of soil salt content and salinization degree, the effects of which are mainly determined by the physiological characteristics and the growth years. The degree of soil salinization increased significantly in the aquaculture ponds, which is mainly caused by the use of chemicals. The correlation between soil salt content and Na+, Cl- is particularly significant. From the results of principal component analysis, Na+, Cl-, Ca2+, Mg2+ and SO42- could be used as main diagnostic factors for salinization in typical estuarine area of the Jiaozhou Bay. The effects of NaCl and sulfate on salt content further affect the degree of salinization in the estuarine area.

  9. Seasonal patterns of phytoplankton biomass and productivity in a tropical estuarine complex (west coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Devassy, V.P.; Goes, J.I.

    Phytoplankton cell numbers and chlorophyll a determinations were made during the premonsoon, monsoon and postmonsoon periods in the Mandovi-Zuari estuarine complex (west coast of India). Primary productivity estimates agreed well with chlorophyll a...

  10. Estuarine Turbidity Maxima and Variations of Aggregate Parameters in the Cam-Nam Trieu Estuary, North Vietnam, in Early Wet Season

    Directory of Open Access Journals (Sweden)

    Vu Duy Vinh

    2018-01-01

    Full Text Available This study aims at exploring the characteristic parameters of the Estuarine Turbidity Maxima (ETM and at investigating their tidal variations within the Cam-Nam Trieu estuary (North Vietnam during the early wet season. Six longitudinal river transects were performed at spring tide. Two types of ETM were observed: an upper well mixed ETM with high Suspended Particulate Matter (SPM concentrations up to the surface at low salinity (0.11 to <1 psu, and a lower ETM confined in a bottom layer over stratified waters at salinities between ~1 psu and 15 psu. Their length depended on the longitudinal salinity gradient and was highest at low tide than at high tide. D50 of the flocs varied between 35 and 90 μm, their excess of density between 60 and 300 kg m−3 and their settling velocity ranged from 0.07 to 0.55 mm s−1 with values between 0.12 and 0.40 mm s−1 in the core of ETMs. The average fractal dimension of flocs was estimated to vary between 1.93 (at high tide to 2.04 (at low tide.

  11. Diversity and abundance of epibiota on invasive and native estuarine gastropods depend on substratum and salinity

    DEFF Research Database (Denmark)

    Thyrring, Jakob; Thomsen, Mads Solgaard; Brunbjerg, Ane Kirstine

    2015-01-01

    ,226 shells representing the common gastropod species in the estuary; Nassarius pauperatus, Bedeva paiva and Batillaria australs from various sites and habitats. Generalized linear models were used to model variability of richness and abundances of common functional groups and species for the above listed...... factors. The five factors accounted for 3-34% of the total deviance explained of the models, with shell type and salinity levels being the only significant factors in nine of 14 models. These results highlight an overwhelming importance of shell type and salinity in explaining estuarine epibiota......Epibiosis is a common life form in estuarine ecosystems, where shell structures in particular, provide important attachment substrate for sessile species. Many studies have quantified variation in epibiota communities against a few environmental factors, but rarely studies have accounted...

  12. Hydrologic influence on redox dynamics in estuarine environments

    Science.gov (United States)

    Michael, H. A.; Kim, K. H.; Guimond, J. A.; Heiss, J.; Ullman, W. J.; Seyfferth, A.

    2017-12-01

    Redox conditions in coastal aquifers control reactions that impact nutrient cycling, contaminant release, and carbon budgets, with implications for water resources and ecosystem health. Hydrologic changes can shift redox boundaries and inputs of reactants, especially in dynamic coastal systems subject to fluctuations on tidal, lunar, and longer timescales. We present two examples of redox shifts in estuarine systems in Delaware, USA: a beach aquifer and a saltmarsh. Beach aquifers are biogeochemical hot spots due to mixing between fresh groundwater and infiltrating seawater. At Cape Henlopen, DE, geochemical measurements identified reactions in the intertidal aquifer that include cycling of carbon, nitrogen, iron, and sulfur. Measurements and modeling illustrate that redox potential as well as the locations of redox reactions shift on tidal to seasonal timescales and in response to changing beach and aquifer properties, impacting overall rates of reactions such as denitrification that reduces N loads to coastal waters. In the St. Jones National Estuarine Research Reserve, tidal fluctuations in channels cause periodic groundwater-surface water exchange, water table movement, and intermittent flooding that varies spatially across the saltmarsh. These changes create shifts in redox potential that are greatest near channels and in the top 20 cm of sediments. The magnitude of redox change depends on hydrologic setting (near channels or in marsh interior), hydrologic conditions (tidal stage, seasonal shifts), as well as prevalence of macropores created by crab burrows that change seasonally with crab activity. These shifts correspond to changes in porewater chemistry that have implications for nutrient cycling and carbon export to the ocean. Understanding hydrologic influence on redox geochemistry is critical for predicting how these systems and their ecosystem services may change in the future in response to anthropogenic and climate change.

  13. Patterns of Diel Variation in Nitrate Concentrations in the Potomac River

    Science.gov (United States)

    Burns, D. A.; Miller, M. P.; Pellerin, B. A.; Capel, P. D.

    2015-12-01

    The Potomac River is the second largest source of nitrogen to Chesapeake Bay, where reducing nutrient loads has been a focus of efforts to improve estuarine trophic status. Two years of high frequency sensor measurements of nitrate (NO3-) concentrations in the Upper Potomac River at the Little Falls gage were analyzed to quantify seasonal variation in the magnitude and timing of the apparent loss of NO3- from the water column that results from diel-driven processes. In addition to broad seasonal and flow-driven variation in NO3- concentrations, clear diel patterns were evident in the river, especially during low flow conditions that follow stormflow by several days. Diel variation was about 0.01 mg N/L in winter and 0.02 to 0.03 mg N/L in summer with intermediate values during spring and fall. This variation was equivalent to 10% occurred during some summer days. Maximum diel concentrations occurred during mid- to late-morning in most seasons, with the most repeatable patterns in summer and wider variation in timing during fall and winter. Diel NO3- loss diminished loads by about 0.6% in winter and 1.3% in summer, and diel-driven processes were minor compared to estimates of total in-stream NO3- loss that averaged about one-third of the inferred groundwater NO3- contribution to the river network. The magnitude of diel NO3- variation was more strongly related to metrics based on water temperature and discharge than to metrics based on photosynthetically active radiation. Despite the fairly low diminishment of NO3- loads attributable to diel variation, estimates of diel NO3- uptake were fairly high compared to published values from smaller streams and rivers. The diel NO3- patterns observed in the Potomac River are consistent with photosynthesis of periphyton as a principal driver which may be linked to denitrification through the release of labile carbon. The extent to which these diel patterns are related to measures of aquatic metabolism are unknown as is the role

  14. Role of Geologic Framework, Paleotopography, Sediment Supply, and Human Modification in the Evolutionary Development of the Northeastern North Carolina Barrier Island System

    Science.gov (United States)

    Riggs, S. R.; Thieler, E. R.; Mallinson, D. A.; Culver, S. J.; Corbett, D. R.; Hoffman, C. W.

    2002-12-01

    The NE North Carolina coastal system contains an exceptionally thick and well preserved Quaternary stratigraphic record that is the focus of a five-year Cooperative Coastal Geology Program between the USGS, several academic institutions, and state agencies. The major goal is to map this Quaternary section on the inner continental shelf, Outer Banks barrier islands, Albemarle-Pamlico estuarine system, and adjacent land areas. The program objectives are to define the geologic framework, develop the detailed evolutionary history, and understand the ongoing process dynamics driving this large, complex, and rapidly changing, high-energy coastal system. Preliminary data synthesis demonstrates that the major controls dictating the present health and future evolution of this coastal system include the following. 1) The regional late Pleistocene morphology constitutes the underlying geologic framework that the Holocene system has inherited. 2) The controlling paleotopography is a series of lowstand drainage basins consisting of trunk and tributary streams and associated interstream divides that are being drowned. 3) Three major sediment sources dictate the highly variable sand resources available to specific barrier segments and include riverine channel and deltaic deposits associated with lowstand trunk streams, the large cross-shelf cape shoal sand deposits, and sand-rich units occurring within the adjacent shoreface and inner-self strata. 4) Wherever large sand supplies have historically been available, the barrier segments occur as complex islands with large sand volumes producing high and wide barriers, whereas barrier segments without adequate sand supplies are sediment starved and occur as simple overwash barriers. 5) Human modification of the barrier islands over the past seven decades represents a major force that has significantly changed the barrier island dynamics and evolution. 6) The Albemarle Embayment appears to have a slightly higher rate of sea-level rise

  15. Making sense of monitoring data using Jupyter Notebooks: a case study of dissolved oxygen dynamics across a fresh-estuarine gradient

    Science.gov (United States)

    Nelson, N.; Munoz-Carpena, R.

    2016-12-01

    In the presented exercise, students (advanced undergraduate-graduate) explore dissolved oxygen (DO) dynamics at three locations along a fresh-estuarine gradient of the Lower St. Johns River, FL (USA). Spatiotemporal DO trends along this gradient vary as a function of (1) tidal influence, and (2) biotic productivity (phytoplankton photosynthesis and community respiration). This combination of influences produces distinct DO behavior across each of the three hydrologically-connected sites. Through analysis of high frequency monitoring data, students are encouraged to think critically about the roles of physical and biological drivers of DO, and how the relative importance of these factors can vary among different locations within a single tidal waterbody. Data from each of the three locations along the river are downloaded with CUAHSI HydroClient, and analysis is performed with a Python-enabled Jupyter Notebook that has been specifically created for this assignment. Jupyter Notebooks include annotated code organized into blocks that are executed one-at-a-time; this format is amenable to classroom teaching, and provides an approachable introduction to Python for inexperienced coders. The outputs from each code block (i.e. graphs, tables) are produced within the Jupyter Notebook, thus allowing students to directly interact with the code. Expected student learning outcomes include increased spatial reasoning, as well as greater understanding of DO cycling, spatiotemporal variability in tidal systems, and challenges associated with collecting and evaluating large data sets. Specific technical learning outcomes include coding in Python for data management and analysis using Jupyter notebooks. This assignment and associated materials are open-access and available on the Science Education Resource Center website.

  16. Water-Quality Monitoring and Biological Integrity Assessment in the Indian River Lagoon, Florida: Status, Trends, and Loadings (1988-1994).

    Science.gov (United States)

    Sigua; Steward; Tweedale

    2000-02-01

    / The Indian River Lagoon (IRL) system that extends from Ponce DeLeon Inlet to Jupiter Inlet is comprised of three interconnected estuarine lagoons: the Mosquito Lagoon (ML), the Banana River Lagoon (BRL), and the Indian River Lagoon (subdivided into North Indian River Lagoon, NIRL and the South Indian River Lagoon, SIRL). The declines in both the areal coverage and species diversity of seagrass communities within the IRL system are believed to be due in part to continued degradation of water quality. Large inflows of phosphorus (P) and nitrogen (N) -laden storm-water from urban areas and agricultural land have been correlated with higher chlorophyll a production in the central, south central, and the south segments of the lagoon. In a system as large and complex as the lagoon, N and P limitations are potentially subject to significant spatial and temporal variability. Total Kjeldahl nitrogen (TN) was higher in the north (1.25 mg/liter) and lower in the south (0.89 mg/liter). The reverse pattern was observed for total P (TP), i.e., lowest in the north (0.03 mg/liter) and highest at the south (0.14 mg/liter) ends of the IRL. This increased P concentration in the SIRL appears to have a significantly large effect on chlorophyll a production compared with the other segments, as indicated by stepwise regression statistics. This relationship can be expressed as follows: South IRL [chlorophyll a] = -8.52 + 162.41 [orthophosphate] + 7.86 [total nitrogen] + 0.38 [turbidity]; R(2) = 0.98**.

  17. Uptake and Fate of Tri-N-Butyltin Cation in Estuarine Bacteria,

    Science.gov (United States)

    1982-04-02

    as well as Yamada and co-workers [31] found trialkyltins, especially tripropyl- tin (TPT) and tributyltin ( TBT ), had the highest antiw-,’.?ial...culture medium £13]. Tributyltin is one of the most toxic forms of tin; a few mg C is suffi- cient to completely inhibit the growth of many...tin-resistant estuarine bacteria was studied. The bacterial isolates accumulated tributyltin to 3.7 to 7.7 mg tin per g dry weight of cells by a non

  18. New Insights Into Valley Formation and Preservation: Geophysical Imaging of the Offshore Trinity River Paleovalley

    Science.gov (United States)

    Speed, C. M.; Swartz, J. M.; Gulick, S. P. S.; Goff, J.

    2017-12-01

    The Trinity River paleovalley is an offshore stratigraphic structure located on the inner continental shelf of the Gulf of Mexico offshore Galveston, Texas. Its formation is linked to the paleo-Trinity system as it existed across the continental shelf during the last glacial period. Newly acquired high-resolution geophysical data have imaged more complexity to the valley morphology and shelf stratigraphy than was previously captured. Significantly, the paleo-Trinity River valley appears to change in the degree of confinement and relief relative to the surrounding strata. Proximal to the modern shoreline, the interpreted time-transgressive erosive surface formed by the paleo-river system is broad and rugose with no single valley, but just 5 km farther offshore the system appears to become confined to a 10 km wide valley structure before again becoming unconfined once again 30 km offshore. Fluvial stratigraphy in this region has a similar degree of complexity in morphology and preservation. A dense geophysical survey of several hundred km is planned for Fall 2017, which will provide unprecedented imaging of the paleovalley morphology and associated stratigraphy. Our analysis leverages robust chirp processing techniques that allow for imaging of strata on the decimeter scale. We will integrate our geophysical results with a wide array of both newly collected and previously published sediment cores. This approach will allow us to address several key questions regarding incised valley formation and preservation on glacial-interglacial timescales including: to what extent do paleo-rivers remain confined within a single broad valley structure, what is the fluvial systems response to transgression, and what stratigraphy is created and preserved at the transition from fluvial to estuarine environments? Our work illustrates that traditional models of incised valley formation and subsequent infilling potentially fail to capture the full breadth of dynamics of past river

  19. Variation in organotin accumulation in relation to the life history in the Japanese eel Anguilla japonica

    Science.gov (United States)

    Ohji, Madoka; Harino, Hiroya; Arai, Takaomi

    2009-08-01

    In order to examine the ecological risks caused by organotin compounds (OTs) in diadromous fish migrating between sea and freshwaters, tributyltin (TBT) and triphenyltin (TPT) compounds and their breakdown products were determined in the catadromous eel Anguilla japonica, which has sea, estuarine and river life histories, collected in Japanese sea, brackish and freshwaters within the same region. Ontogenic changes in otolith strontium (Sr) and calcium (Ca) concentrations were examined along the life history transect to discriminate the migration type. There were generally three different patterns, which were categorized as 'sea eels', 'estuarine eels' and 'river eels' according to the otolith Sr:Ca ratio. The concentrations of TBT in silver eels (mature eels) were significantly higher than that in yellow eels (immature eels), and the percentages of TBT were also higher in silver eels than in yellow eels. A positive correlation was found between TBT concentration and the gonad-somatic index (GSI). It is thus considered that silver eels have a higher risk of contamination by TBT than yellow eels. TBT and TPT concentrations in sea eels were significantly higher than those in river eels, while no significant differences were observed in TBT and TPT concentrations in estuarine eels compared to sea and river eels. These results suggest that sea eels have a higher ecological risk of OT contamination than river eels during their life history, and the risk of OTs in estuarine eels is considered to be intermediate between that of sea and river eels. Positive linear relationships were found between Sr:Ca ratios and the concentrations of TBT and TPT. Therefore, these results suggest that the ecological risk of OTs increase as the sea residence period in the eel becomes longer. TBT and TPT concentrations in sea eels were significantly higher than those in river eels even at the same growth stage. Thus, it is clear that migratory type is the most important factor for OT

  20. Evaluating Cumulative Ecosystem Response to Restoration Projects in the Columbia River Estuary, Annual Report 2004

    Energy Technology Data Exchange (ETDEWEB)

    Diefenderfer, Heida L.; Roegner, Curtis; Thom, Ronald M.; Dawley, Earl M.; Whiting, Allan H.; Johnson, Gary E.; Sobocinski, Kathryn L.; Anderson, Michael G.; Ebberts, Blaine

    2005-12-15

    The restoration of wetland salmon habitat in the tidal portion of the Columbia River is occurring at an accelerating pace and is anticipated to improve habitat quality and effect hydrological reconnection between existing and restored habitats. Currently multiple groups are applying a variety of restoration strategies in an attempt to emulate historic estuarine processes. However, the region lacks both a standardized means of evaluating the effectiveness of individual projects as well as methods for determining the cumulative effects of all restoration projects on a regional scale. This project is working to establish a framework to evaluate individual and cumulative ecosystem responses to restoration activities in order to validate the effectiveness of habitat restoration activities designed to benefit salmon through improvements to habitat quality and habitat opportunity (i.e. access) in the Columbia River from Bonneville Dam to the ocean. The review and synthesis of approaches to measure the cumulative effects of multiple restoration projects focused on defining methods and metrics of relevance to the CRE, and, in particular, juvenile salmon use of this system. An extensive literature review found no previous study assessing the cumulative effects of multiple restoration projects on the fundamental processes and functions of a large estuarine system, although studies are underway in other large land-margin ecosystems including the Florida Everglades and the Louisiana coastal wetlands. Literature from a variety of scientific disciplines was consulted to identify the ways that effects can accumulate (e.g., delayed effects, cross-boundary effects, compounding effects, indirect effects, triggers and thresholds) as well as standard and innovative tools and methods utilized in cumulative effects analyses: conceptual models, matrices, checklists, modeling, trends analysis, geographic information systems, carrying capacity analysis, and ecosystem analysis. Potential

  1. Experimental study on the effect of ingested lead shot on Estuarine crocodiles: significance for Finniss River field studies

    International Nuclear Information System (INIS)

    Hammerton, K.M.

    2002-01-01

    Lead has long been recognised as a cumulative metabolic poison in humans, domestic animals and wildlife. Because of the many industrial activities that have brought about its widespread distribution, lead is ubiquitous in the environment. For example, uranium mining at the Rum Jungle site on the Finniss River, Northern Territory, resulted in contamination of river sediments with lead. Today, lead levels remain at about 250 mg kg-1 of wet river sediment within the immediate vicinity of the mine. Another potential source of lead poisoning in wildlife is the use of lead gunshot for hunting. Mortality in wild waterfowl caused by the ingestion of spent lead shot has been recognised in North America and Europe for over a century. An experimental study was undertaken to assess the above hypothesis on the effects of lead in the environs of crocodiles. The specific effects of lead intoxication arise mainly from the interaction of lead with the enzymatic processes in the haem biosynthetic pathway. One of these enzymes, δ-aminolevulinic acid dehydratase (ALAD), catalyses the condensation of two molecules of aminolevulinic acid to produce the pyrrole, porphobilinogen, the building block of the haem molecule. ALAD is a metalloenzyme requiring zinc for activity and is inhibited by lead displacing the essential zinc. This inhibition of ALAD by lead has been used as a specific biomarker for lead poisoning in fish, birds and mammals. An assay system was developed for the measurement of ALAD activity in crocodilian blood. It was found that ALAD was inhibited by up to 90% during the first week after exposure of the crocodiles to lead shot. There was an inverse correlation between BPb and ALAD activity throughout the 42 week experimental period. BPb concentrations greater than 100 mg dL-1 produced significant inhibition of ALAD. The results indicated that ALAD inhibition could be used as a specific biomarker of lead toxicity in crocodiles

  2. Assessment of Godavari estuarine mangrove ecosystem through trace metal studies

    Digital Repository Service at National Institute of Oceanography (India)

    Ray, A.K.; Tripathy, S.C.; Patra, S.; Sarma, V.V.

    York), pp. 265?286, 1975. 12. Ranga Rao, V., Reddy, B. S. R., Raman, A. V. & Ramana Murthy, M. V. Oceanographic features of the Bay-mangrove waterways of Coringa, East coast of India. Proc. AP Akad. Sc., 7 (2): 135-142, 2003. 13. Robertson, A. I...-Godavari estuarine mangrove ecosystem, Andhra Pradesh, India. Indian J Mar. Sc. (in press), 2004. 18. Turkian, K. K. and Wedephol, K. H. Distribution of the elements in some major units of the earth crust. Bull. Geol. Soc. Amer., 72: 175-192, 1961. 19. Twilley, R...

  3. A checklist of malacofauna of the Vellar Estuarine Mangroves, India

    Directory of Open Access Journals (Sweden)

    K. Kesavan

    2009-07-01

    Full Text Available A survey conducted to know the diversity of malacofauna in Vellar estuarine mangroves (southeast coast of India. In this study, 13 species of molluscs (10 species of gastropods - Melampus ceylonicus, Cerithidea cingulata, Cassidula nucleus, Pythia plicata, Neritina (Dostia violacea, Littorina scabra, Littorina melanostoma, Ellobium aurisjudae, C. obtusa T. telescopium and Assiminea nitida and 3 species of bivalves - Perna viridis, Crassostrea madrasensis and Modiolus metcalfei were recorded. M. pulchella, C. obtusa, L. scabra and N. violacea were found arboreal. T. telescopium, C. cingulata and E. aurisjudae were found crawling on the intertidal mud.

  4. The complex early life history of a marine estuarine-opportunist fish species, Solea turbynei (Soleidae from temperate South Africa

    Directory of Open Access Journals (Sweden)

    Nadine A. Strydom

    2015-06-01

    Full Text Available The early life history stages and ecology of Solea turbynei, a marine estuarine-opportunist species, is described from nursery areas in Algoa Bay, South Africa. Early life history stages were collected over multiple years from known nursery habitats using plankton, fyke and larval seine nets. The larvae are described using morphometric measurements, meristic counts and pigmentation based on 29 individuals. Solea turbynei is differentiated from other Soleidae by the small size at flexion (3-4 mm, low myomere count and presence of two characteristic blotches of pigment on the dorsal fin. This species has a unique early life history strategy in that the larvae progressively span nearshore, surf zone and estuarine habitats with ontogeny. Abundance of preflexion stages peaks in summer in nearshore waters, indicative of peak spawning period but preflexion larvae are present throughout the year, indicating protracted spawning by adults. At flexion stage, larvae utilize surf zones where metamorphosis and settlement takes place. Early juveniles migrate into the sandy lower reaches of estuaries, after which fish take up residency to adulthood. Warm water is important for larval growth and survival in the nearshore, while turbidity shows a positive relationship with recruitment into estuarine nurseries.

  5. High genetic connectivity among estuarine populations of the riverbream Acanthopagrus vagus along the southern African coast

    Science.gov (United States)

    Oosthuizen, Carel J.; Cowley, Paul D.; Kyle, Scotty R.; Bloomer, Paulette

    2016-12-01

    Physical and/or physiological constraints are assumed to isolate fish populations confined to or dependent on estuarine habitats. Strong isolation by distance is thus expected to affect connectivity. Such structuring has important implications for sustainable utilisation and replenishment of estuarine stocks that are heavily exploited. Here we present a preliminary investigation of the phylogenetic relationships of the riverbream (Acanthopagrus species) along the southern African coast and the geographic genetic structure of what appears to be a locally endemic species or lineage. Mitochondrial DNA (mtDNA) cytochrome b sequences support the notion that the species occurring along the southern African coast is A. vagus and not A. berda as previously thought. Yet, the taxonomy of this widespread Indo-West Pacific species or species-complex requires more in-depth investigation. No genetic differentiation was detected among estuarine populations of A. vagus based on the analyses of mtDNA ND2 gene sequences and 10 polymorphic nuclear microsatellite markers. The star-like genealogy and statistical analyses are consistent with a recent population expansion event. Spatial analyses of microsatellite genotypes fail to reject the null hypothesis of panmixia, indicative of a recent population expansion or ongoing gene flow between different estuaries. The northern localities were identified as containing most of the observed variation. This study not only provides insight into the phylogenetic relationship of A. vagus relative to other Acanthopagrus species but also sheds light on the demographic history and contemporary gene flow of the species.

  6. Mercury biogeochemistry in the Idrija River, Slovenia, from above the mine into the Gulf of Trieste

    Science.gov (United States)

    Hines, M.E.; Horvat, M.; Faganeli, J.; Bonzongo, J.-C.J.; Barkay, T.; Major, E.B.; Scott, K.J.; Bailey, E.A.; Warwick, J.J.; Lyons, W.B.

    2000-01-01

    The Idrija Mine is the second largest Hg mine in the world which operated for 500 years. Mercury (Hg)-laden tailings still line the banks, and the system is a threat to the Idrija River and water bodies downstream including the Soca/Isonzo River and the Gulf of Trieste in the northern Adriatic Sea. A multidisciplinary study was conducted in June 1998 on water samples collected throughout the Idrija and Soca River systems and waters and sediments in the Gulf. Total Hg in the Idrija River increased >20-fold downstream of the mine from 60 ng liter-1 with methyl mercury (MeHg) accounting for ~0.5%. Concentrations increased again downstream and into the estuary with MeHg accounting for nearly 1.5% of the total. While bacteria upstream of the mine did not contain mercury detoxification genes (mer), such genes were detected in bacteria collected downstream. Benthic macroinvertebrate diversity decreased downstream of the mine. Gulf waters near the river mouth contained up to 65 ng liter-1 total Hg with ~0.05 ng liter-1 MeHg. Gulf sediments near the river mouth contained 40 ??g g-1 total Hg with MeHg concentrations of about 3 ng g-1. Hg in sediment pore waters varied between 1 and 8 ng liter-1, with MeHg accounting for up to 85%. Hg methylation and MeHg demethylation were active in Gulf sediments with highest activities near the surface. MeHg was degraded by an oxidative pathway with >97% C released from MeHg as CO2. Hg methylation depth profiles resembled profiles of dissolved MeHg. Hg-laden waters still strongly impact the riverine, estuarine, and marine systems. Macroinvertebrates and bacteria in the Idrija River responded to Hg stress, and high Hg levels persist into the Gulf. Increases in total Hg and MeHg in the estuary demonstrate the remobilization of Hg, presumably as HgS dissolution and recycling. Gulf sediments actively produce MeHg, which enters bottom waters and presumably the marine food chain. (C) 2000 Academic Press.

  7. What role do beds of submerged macrophytes play in structuring estuarine fish assemblages? Lessons from a warm-temperate South African estuary

    Science.gov (United States)

    Sheppard, Jill N.; James, Nicola C.; Whitfield, Alan K.; Cowley, Paul D.

    2011-11-01

    Habitat variability is one of the factors influencing species richness within estuarine systems, and a loss of habitat can result in a restructuring of the estuarine ichthyofaunal assemblage, particularly if these conditions persist over long time periods. The potential effects of the loss of extensive submerged macrophyte beds ( Ruppia cirrhosa and Potamogeton pectinatus) on an estuarine fish assemblage were investigated through an analysis of a long-term seine net catch dataset from the temporarily open/closed East Kleinemonde Estuary, South Africa. Catch data for a 12-year period, encompassing six years of macrophyte presence and six years of macrophyte senescence, indicated that the loss of this habitat did not influence species richness but changes in the relative abundance of certain species were evident. A shift in dominance from vegetation-associated species to those associated with sandy environments ( e.g. members of the family Mugilidae) was observed. However, species wholly dependent on macrophytes such as the critically endangered estuarine pipefish Syngnathus watermeyeri were only recorded during years when macrophyte beds were present, while vegetation-associated species such as the sparid Rhabdosargus holubi persisted at lower levels of relative abundance. The reduced abundance of all vegetation-associated fish species during years of macrophyte senescence was probably reflective of declining food resources resulting from the loss of macrophyte beds and/or increased vulnerability to predation. Submerged beds of aquatic plants are therefore important habitats within temporarily open/closed estuaries, South Africa's dominant estuary type.

  8. Mapping estuarine distributions of the non-indigenous Japanese Eelgrass Zostera japonica using Color Infrared Aerial Photography

    Science.gov (United States)

    This presentation describes a technique for mapping distributions of the nonindigenous Japanese eelgrass Zostera japonica in estuarine ecosystems of the Pacific Northwest. The relatively broad distribution of this intertidal plant, often on very soft substrate, makes classical g...

  9. Human induced discharge diversion in a tropical delta and its environmental implications: The Patía River, Colombia

    Science.gov (United States)

    Restrepo, Juan D.; Kettner, Albert

    2012-03-01

    SummaryThe Patía River, the number one in terms of sediment yield ˜1500 t km-2 yr-1 draining the western South America, has the most extensive and well developed delta on the Pacific coast, measuring 1700 km2. During the Holocene, nature forced the Patía delta to the south; however, a major water diversion, starting in 1972, diverted the Patía flow to the Sanguianga River, the latter, a small stream draining internal lakes from the Pacific lowlands. This human induced discharge diversion shifted the active delta plain back to the north and changed the northern estuarine system into an active delta plain. Overall, major environmental consequences of this discharge diversion in terms of morphological changes along the delta coast and distributary channels, are evidenced by: (1) coastal retreat along the abandoned delta lobe; 63% of the southern shoreline is retreating at maximum rates of 7 m yr-1, with a corresponding coastal land loss of 106 m yr-1; (2) transgressive barrier islands with exposed peat soils in the surf zone; (3) abandonment of former active distributaries in the southern delta plain with associated closing of inlets and formation of ebb tidal deltas; (4) breaching events on barrier islands; and (5) distributary channel accretion in the northern delta plain by morphological processes such as sedimentation (also in crevasses), overbank flow, increasing width of levees, interdistributary channel fill, and colonization of pioneer mangrove. The Sanguianga Mangrove National Park (SMNP), the largest mangrove reserve in Colombia, measuring 800 km2, lies in this former estuary, where major hydrologic and sedimentation changes are occurring. Observed environmental changes in the SMNP, include (1) seaward advance of the sub-aqueous delta front at the Sanquianga inlet evidenced by an increase in tidal flat area from 5.4 Mm2 in 1986 to 14 Mm2 in 2001; (2) freshening conditions in the Sanguianga distributary channel, a hydrologic change that has shifted the

  10. Survey of organotin compounds in rivers and coastal environments in Portugal 1999-2000

    Energy Technology Data Exchange (ETDEWEB)

    Diez, Sergi [Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain)]. E-mail: sdsqam@cid.csic.es; Lacorte, Silvia [Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Viana, Paula [Direcao Geral do Ambiente, Ministerio do Ambiente, Rua da Murgueira, Zambujal, 2720 Amadora (Portugal); Barcelo, Damia [Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Bayona, Josep M. [Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain)

    2005-08-15

    In the period from April 1999 to May 2000, organotin pollution, namely butyl and phenyltins, was investigated in coastal and continental waters (46 stations), estuarine sediments (15 stations) and mussels (Mytilus galloprovincialis) (13 stations) throughout Portugal. Sampling points were chosen in areas of specific industrial, agricultural and harbor activities. Butyltins (BTs) were the only tin species identified of which tributyltin (TBT) was found in the whole area. Concentrations of TBT in river water ranged from 3 to 30 ng L{sup -1} (as Sn), marine sediment ranged from 4 to 12 {mu}g kg{sup -1} (as Sn), whereas concentrations in mussel tissue ranged from 2.5 to 490 {mu}g kg{sup -1} (as Sn). Given that some water samples appeared to be contaminated by higher monobutyltin (MBT) and dibutyltin (DBT) concentrations, the role of biological degradation and direct inputs from agricultural and industrial applications areas are discussed. The study compares depleted butyltin pollution in sediments and mussels of the Portuguese coastline associated with antifouling paints with previously reported levels. Inputs in river waters are more related to (i) PVC leaching and (ii) industrial sources, in some cases discharged by municipal wastewaters. - Survey data illustrate the complexities of organotin sources and cycling in coastal environments.

  11. Survey of organotin compounds in rivers and coastal environments in Portugal 1999-2000

    International Nuclear Information System (INIS)

    Diez, Sergi; Lacorte, Silvia; Viana, Paula; Barcelo, Damia; Bayona, Josep M.

    2005-01-01

    In the period from April 1999 to May 2000, organotin pollution, namely butyl and phenyltins, was investigated in coastal and continental waters (46 stations), estuarine sediments (15 stations) and mussels (Mytilus galloprovincialis) (13 stations) throughout Portugal. Sampling points were chosen in areas of specific industrial, agricultural and harbor activities. Butyltins (BTs) were the only tin species identified of which tributyltin (TBT) was found in the whole area. Concentrations of TBT in river water ranged from 3 to 30 ng L -1 (as Sn), marine sediment ranged from 4 to 12 μg kg -1 (as Sn), whereas concentrations in mussel tissue ranged from 2.5 to 490 μg kg -1 (as Sn). Given that some water samples appeared to be contaminated by higher monobutyltin (MBT) and dibutyltin (DBT) concentrations, the role of biological degradation and direct inputs from agricultural and industrial applications areas are discussed. The study compares depleted butyltin pollution in sediments and mussels of the Portuguese coastline associated with antifouling paints with previously reported levels. Inputs in river waters are more related to (i) PVC leaching and (ii) industrial sources, in some cases discharged by municipal wastewaters. - Survey data illustrate the complexities of organotin sources and cycling in coastal environments

  12. Dissolved and colloidal trace elements in the Mississippi River Delta outflow after Hurricanes Katrina and Rita

    Science.gov (United States)

    Shim, Moo-Joon; Swarzenski, Peter W.; Shiller, Alan M.

    2012-01-01

    The Mississippi River delta outflow region is periodically disturbed by tropical weather systems including major hurricanes, which can terminate seasonal bottom water hypoxia and cause the resuspension of shelf bottom sediments which could result in the injection of trace elements into the water column. In the summer of 2005, Hurricanes Katrina and Rita passed over the Louisiana Shelf within a month of each other. Three weeks after Rita, we collected water samples in the Mississippi River delta outflow, examining the distributions of trace elements to study the effect of Hurricanes Katrina and Rita. We observed limited stratification on the shelf and bottom waters that were no longer hypoxic. This resulted, for instance, in bottom water dissolved Mn being lower than is typically observed during hypoxia, but with concentrations still compatible with Mn–O2 trends previously reported. Interestingly, for no element were we able to identify an obvious effect of sediment resuspension on its distribution. In general, elemental distributions were compatible with previous observations in the Mississippi outflow system. Co and Re, which have not been reported for this system previously, showed behavior consistent with other systems: input for Co likely from desorption and conservative mixing for Re. For Cs, an element for which there is little information regarding its estuarine behavior, conservative mixing was also observed. Our filtration method, which allowed us to distinguish the dissolved (<0.02 μm) from colloidal (0.02–0.45 μm) phase, revealed significant colloidal fractions for Fe and Zn, only. For Fe, the colloidal phase was the dominant fraction and was rapidly removed at low salinity. Dissolved Fe, in contrast, persisted out to mid-salinities, being removed in a similar fashion to nitrate. This ability to distinguish the smaller Fe (likely dominantly organically complexed) from larger colloidal suspensates may be useful in better interpreting the

  13. Identification and effects of anthropogenic emissions of U and Th on the composition of sediments in a river/estuarine system in Southern Spain

    International Nuclear Information System (INIS)

    Martinez-Aguirre, A.; Garcia-Leon, M.

    1994-01-01

    A study of the distribution of natural radionuclides in different fractions of river bottom sediments has been carried out. The study has shown that the majority of the total U in the sediment is located in the non-residual fraction of the sediment, while Th is more suitable to be present in the residual fraction of the sediments. Also, it has been found that coprecipitation with amorphous ferromanganese oxyhydroxides is the main process of incorporation of U- and Th-isotopes from the water column to suspended matter or bottom sediments. The distribution of the radionuclides and the analysis of some relevant activity ratios in different fractions of sediments has made an unequivocal connection between the enhanced U content in river sediments and the waste discharged into the Odiel and Tinto rivers by the operation in the vicinity of phosphate fertilizer industries. (Author)

  14. Fisheries-Independent Biological and Environmental Trawl Data from the Texas Parks and Wildlife Department (1982-2005) as Part of the Comparative Assessment of Gulf Estuarine Systems (CAGES) Database (NODC Accession 0115183)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CAGES program (Comparative Assessment of Gulf Estuarine Systems) is designed to examine the differences between estuarine ecosystems and investigate why some are...

  15. Role of salinity in structuring the intertidal meiofauna of a tropical estuarine beach: Field evidence

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Parulekar, A.H.

    Community structure of meiofauna was studied for 12 months (July 1991-June 1992) on an estuarine intertidal beach at Siridao, Goa (India). The temperature of the surf zone water ranged from 26.5 degrees to 30.7 degrees C; salinity from 8.3 to 34.4 x...

  16. Gonadal disorder in the thinlip grey mullet (Liza ramada, Risso 1827) as a biomarker of environmental stress in surface waters.

    Science.gov (United States)

    Tancioni, Lorenzo; Caprioli, Riccardo; Al-Khafaji, Ayad Hantoosh Dawood; Mancini, Laura; Boglione, Clara; Ciccotti, Eleonora; Cataudella, Stefano

    2015-02-05

    The aim of this study was to evaluate the use of gonadal alterations in the thinlip grey mullet (Liza ramada) as a biological indicator in assessing aquatic ecosystems health, with particular emphasis to river ecosystems exposed to sewage discharges. For this purpose, the reproductive status and the presence of gonadal alterations were studied in 206 mullets collected from two sites on the low course of the Tiber River, downstream of a large urban sewage treatment plant and in the estuarine area, and from an uncontaminated pond considered as reference site. Intersex and irregularly shaped gonads were observed in 20.8% of the mullets from the most polluted site, and intersex gonads in 10.3% of those from the estuarine area. No alterations were detected in the fish from the reference site, which also showed distinct stages of gonadal development. Conversely, unclear stages of testicular and ovary development were observed in the fish from the two polluted river sites. The results of this study suggest that L. ramada may represent a sentinel species in environmental risk assessment and support the use of gonadal alterations of this species as a bioindicator for extensive monitoring of pollution in lower stretches of rivers and estuarine areas.

  17. Gonadal Disorder in the Thinlip Grey Mullet (Liza ramada, Risso 1827 as a Biomarker of Environmental Stress in Surface Waters

    Directory of Open Access Journals (Sweden)

    Lorenzo Tancioni

    2015-02-01

    Full Text Available The aim of this study was to evaluate the use of gonadal alterations in the thinlip grey mullet (Liza ramada as a biological indicator in assessing aquatic ecosystems health, with particular emphasis to river ecosystems exposed to sewage discharges. For this purpose, the reproductive status and the presence of gonadal alterations were studied in 206 mullets collected from two sites on the low course of the Tiber River, downstream of a large urban sewage treatment plant and in the estuarine area, and from an uncontaminated pond considered as reference site. Intersex and irregularly shaped gonads were observed in 20.8% of the mullets from the most polluted site, and intersex gonads in 10.3% of those from the estuarine area. No alterations were detected in the fish from the reference site, which also showed distinct stages of gonadal development. Conversely, unclear stages of testicular and ovary development were observed in the fish from the two polluted river sites. The results of this study suggest that L. ramada may represent a sentinel species in environmental risk assessment and support the use of gonadal alterations of this species as a bioindicator for extensive monitoring of pollution in lower stretches of rivers and estuarine areas.

  18. Composition of functional ecological guilds of the fish fauna of the internal sector of the Amazon Estuary, Pará, Brazil.

    Science.gov (United States)

    Mourão, Keila R M; Ferreira, Valdimere; Lucena-Frédou, Flávia

    2014-12-01

    The present study describes the spatial and temporal structure of the estuarine fish community in the internal sector of the Amazon Estuary. Samples were obtained in the main channels and tidal creeks of Guajará and Marajó Bays and Guamá River. A total of 41,516 fish specimens were collected, representing 136 taxa, 38 families and 12 orders. In the dry season, the mean salinity of the main channel increased along a limnic-marine gradient, between the Guamá River and the Marajó Bay. Species richness was lowest in the mouth of the Guamá River and in the right margin of the Guajará Bay. Fish species composition and environmental guilds differed markedly among areas: Migrants and Freshwater Stragglers were dominant in the Guamá River and the Guajará Bay, while Estuarine, Marine Stragglers and Migrants predominated in the Marajó Bay. However, the trophic guilds were still relatively well balanced, in functional terms. Piscivores and Zoobenthivores were the dominant feeding functional groups in all the studied areas. In this study, the assessment of the community and the use of the guild approach were efficient to describe the structure and functioning of the assemblages of estuarine fish also helping to assess the anthropogenic pressures in the area.

  19. Gonadal Disorder in the Thinlip Grey Mullet (Liza ramada, Risso 1827) as a Biomarker of Environmental Stress in Surface Waters

    Science.gov (United States)

    Tancioni, Lorenzo; Caprioli, Riccardo; Dawood Al-Khafaji, Ayad Hantoosh; Mancini, Laura; Boglione, Clara; Ciccotti, Eleonora; Cataudella, Stefano

    2015-01-01

    The aim of this study was to evaluate the use of gonadal alterations in the thinlip grey mullet (Liza ramada) as a biological indicator in assessing aquatic ecosystems health, with particular emphasis to river ecosystems exposed to sewage discharges. For this purpose, the reproductive status and the presence of gonadal alterations were studied in 206 mullets collected from two sites on the low course of the Tiber River, downstream of a large urban sewage treatment plant and in the estuarine area, and from an uncontaminated pond considered as reference site. Intersex and irregularly shaped gonads were observed in 20.8% of the mullets from the most polluted site, and intersex gonads in 10.3% of those from the estuarine area. No alterations were detected in the fish from the reference site, which also showed distinct stages of gonadal development. Conversely, unclear stages of testicular and ovary development were observed in the fish from the two polluted river sites. The results of this study suggest that L. ramada may represent a sentinel species in environmental risk assessment and support the use of gonadal alterations of this species as a bioindicator for extensive monitoring of pollution in lower stretches of rivers and estuarine areas. PMID:25664693

  20. Surfactant-induced mobilisation of trace metals from estuarine sediment: Implications for contaminant bioaccessibility and remediation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Anu [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Turner, Andrew [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: aturner@plymouth.ac.uk

    2009-02-15

    The mobilisation of metals (Al, Fe, Cd, Cu, Mn, Ni, Pb, Sn, Zn) from contaminated estuarine sediment has been examined using commercially available surfactants. Metal release by the anionic surfactant, sodium dodecyl sulphate (SDS), increased with increasing amphiphile concentration up to and above its critical micelle concentration (CMC). Metal mobilisation by the bile acid salt, sodium taurocholate, and the nonionic surfactant, Triton X-100, however, did not vary with amphiphile concentration. SDS was the most efficient surfactant in mobilising metals from the sample, and Cd, Cu and Ni were released to the greatest extents (12-18% of total metal at [SDS] > CMC). Metal mobilisation appeared to proceed via complexation with anionic amphiphiles and denudation of hydrophobic host phases. Surfactants may play an important role in the solubilisation of metals in the digestive environment of deposit-feeding animals and, potentially, in the remediation of metal-contaminated soil and sediment. - Significant quantities of metals are mobilised from estuarine sediment by commercially available surfactants.

  1. Predicting the Spatial Distribution of Organic Contaminants in an Estuarine System using a Random Forest Approach

    Science.gov (United States)

    Modeling the magnitude and distribution of estuarine sediment contamination by pollutants of historic (e.g. PCB) and emerging concern (e.g., personal care products, PCP) is often limited by incomplete site knowledge and inadequate sediment contamination sampling. We tested a mode...

  2. Export and retention of dissolved inorganic nutrients in the Cachoeira River, Ilhéus, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Maria A.M. SILVA

    2010-02-01

    Full Text Available Dissolved inorganic nutrient concentrations and physical-chemical variables were determined in the lower reaches of the Cachoeira River watershed, from November 2003 to October 2004. Concentration of nutrients were high and highly variable. Mean concentrations and standard deviation of ammonium, nitrite, nitrate, phosphate and silicate were 25.4 ± 25.1; 3.9 ± 3.9; 62.2 ± 54.9; 15.8 ± 9.0 and 129.0 ± 5.6 (μmol L-1, respectively. Nutrient retention was observed mainly during the dry season. Chlorophyll-a concentrations were especially high in those periods. The Cachoeira River can be considered eutrophicated, and such condition becomes more intense with low fluvial flow during the dry months. Despite the spatial/temporal changes of the species of inorganic nitrogen, a removal of dissolved inorganic nitrogen was observed in relation to dissolved silicon and to phosphorus, with consequences for estuarine biogeochemistry. The basin exports annually about 3.5, 2.2 and 0.3 t y-1 of dissolved silicon, nitrogen, and phosphate to the estuary, respectively. The eutrophication and growth of macrophytes is responsible for most of these changes in nutrient fluxes to the estuary and coastal waters.

  3. A magnetic record of heavy metal pollution in the Yangtze River subaqueous delta

    International Nuclear Information System (INIS)

    Dong, Chenyin; Zhang, Weiguo; Ma, Honglei; Feng, Huan; Lu, Honghua; Dong, Yan; Yu, Lizhong

    2014-01-01

    The rapid industrial development in the Yangtze River watershed over the last several decades has drawn great attention with respect to heavy metal pollution to the Yangtze River estuary and nearby coastal areas. In this study, a 236 cm long sediment core was retrieved from the Yangtze River subaqueous delta (122°36′ E, 31°00′ N) in 2008 and analyzed for magnetic properties and geochemical compositions to investigate heavy metal pollution history. The activity of 137 Cs peaked at depth 140 cm, with a broad plateau between 120 cm and 140 cm, suggesting an average sedimentation rate of 3.11 cm yr −1 for the upper 140 cm layer. Magnetic susceptibility (χ), saturation isothermal remanent magnetization (SIRM), anhysteretic remanent magnetization (χ ARM ) and heavy metal enrichment factors (EF) all showed an upward increase trend above depth 140 cm, suggesting that increased ferrimagnetic mineral concentration was accompanied by heavy metal enrich