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Sample records for kachemak bay water

  1. National Status and Trends: Bioeffects Program - Kachemak Bay Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study was based on the sediment quality triad (SQT) approach. A stratified probabilistic sampling design was utilized to characterize the Kachemak Bay system in...

  2. Juvenile groundfish habitat in Kachemak Bay, Alaska, during late summer

    Science.gov (United States)

    Abookire, Alisa A.; Piatt, John F.; Norcross, Brenda L.

    2001-01-01

    We investigated the habitat of juvenile groundfishes in relation to depth, water temperature, and salinity in Kachemak Bay, Alaska. Stations ranging in depth from 10 to 70 m and with sand or mud-sand substrates were sampled with a small-meshed beam trawl in August-September of 1994 to 1999. A total of 8,201 fishes were captured, comprising at least 52 species. Most fishes (91%) had a total length 5% of the total catch) were flathead sole Hippoglossoides elassodon, slim sculpin Radulinus asprellus, Pacific halibut Hippoglossus stenolepis, and arrowtooth flounder Atheresthes stomias. Depth accounted for most of the spatial variability in juvenile groundfish abundance, and neither temperature nor salinity was correlated with fish abundance. Juvenile groundfishes concentrated in either shallow (less than or equal to 20 m) or deep (50-70 m) water, with co-occurrence of some species between 30-40 m. Shallow fishes were the rock soles, Pacific halibut, and great sculpin Myoxocephalus polyacanthocephalus. Deep species were flathead sole, slim sculpin, spinycheek starsnout Bathyagonus infraspinatus, rex sole Glyptocephalus zachirus, tadpole sculpin Psychrolutes paradoxus, and whitebarred prickleback Poroclinus rothrocki. This 6-year study provides baseline data on relative abundance and distribution of juvenile groundfishes in Kachemak Bay and may provide a useful tool for predicting the presence of species in similar habitats in other areas of Alaska.

  3. Field guide to the Mesozoic accretionary complex along Turnagain Arm and Kachemak Bay, south-central Alaska

    Science.gov (United States)

    Bradley, Dwight C.; Kusky, Timothy M.; Karl, Susan M.; Haeussler, Peter J.

    1997-01-01

    Turnagain Arm, just east of Anchorage, provides a readily accessible, world-class cross section through a Mesozoic accretionary wedge. Nearly continuous exposures along the Seward Highway, the Alaska Railroad, and the shoreline of Turnagain Arm display the two main constituent units of the Chugach terrane: the McHugh Complex and Valdez Group. In this paper we describe seven bedrock geology stops along Turnagain Arm, and two others in the Chugach Mountains just to the north (Stops 1-7 and 9), which will be visited as part of the May, 1997 field trip of the Alaska Geological Society. Outcrops along Turnagain Arm have already been described in two excellent guidebook articles (Clark, 1981; Winkler and others 1984), both of which remain as useful and valid today as when first published. Since the early 1980's, studies along Turnagain Arm have addressed radiolarian ages of chert and conodont ages of limestone in the McHugh Complex (Nelson and others, 1986, 1987); geochemistry of basalt in the McHugh Complex (Nelson and Blome, 1991); post-accretion brittle faulting (Bradley and Kusky, 1990; Kusky and others, 1997); and the age and tectonic setting of gold mineralization (Haeussler and others, 1995). Highlights of these newer findings will described both in the text below, and in the stop descriptions.Superb exposures along the southeastern shore of Kachemak Bay show several other features of the McHugh Complex that are either absent or less convincing along Turnagain Arm. While none of these outcrops can be reached via the main road network, they are still reasonably accessible - all are within an hour by motorboat from Homer, seas permitting. Here, we describe seven outcrops along the shore of Kachemak Bay that we studied between 1989 and 1993 during geologic mapping of the Seldovia 1:250,000- scale quadrangle. These outcrops (Stops 61-67) will not be part of the 1997 itinerary, but are included here tor the benefit of those who may wish to visit them later.

  4. Temporal and geographic variation in fish communities of lower Cook Inlet, Alaska

    Science.gov (United States)

    Robards, Martin D.; Piatt, John F.; Kettle, Arthur B.; Abookire, Alisa A.

    1999-01-01

    Nearshore and shelf fish communities were studied in three areas of lower Cook Inlet, Alaska: the Barren Islands (oceanic and well-mixed waters), Kachemak Bay (mixed oceanic waters with significant freshwater runoff), and Chisik Island (estuarine waters). Fish were sampled with beach seines (n=413 sets) and midwater trawls (n=39 sets). We found that lower Cook Inlet supported a diverse nearshore fish community of at least 52 species. Fifty of these species were caught in Kachemak Bay, 24 at Chisik Island, and 12 at the Barren Islands. Pacific sand lance dominated Barren Islands and Kachemak Bay nearshore habitats, comprising 99% and 71% of total individuals, respectively. The nearshore Chisik Island fish community was not dominated by any one species; instead it exhibited higher diversity. These spatial differences appeared linked to local oceanographic regimes and sediment influx. Analysis of historical data revealed that the nearshore Kachemak Bay fish community changed significantly between 1976 and 1996, showing increased diversity and abundance in several taxa, notably gadids, salmonids, pleuronectids, and sculpins. Decadal differences appeared to be related to large-scale climate changes in the North Pacific. Catches of most taxa peaked in May-August, and were low during other months of the year. Several species were present for only part of the summer. Species composition of seine catches differed significantly between consecutive high and low tides, but not between consecutive sets or years. Midwater trawls took 26 species, 14 of which were present in Kachemak Bay, 19 near Chisik Island, and 7 at the Barren Islands. Community structures in shelf and nearshore waters were similar: diversity was high and abundance low at Chisik Island, whereas a few abundant species dominated at both Kachemak Bay and the Barren Islands. In addition, the low fish abundance near Chisik Island appeared to be related to declining seabird numbers at this colony.

  5. Depth and substrate as determinants of distribution of juvenile flathead sole (Hippoglossoides elassodon) and rock sole (Pleuronectes bilineatus), in Kachemak Bay, Alaska

    Science.gov (United States)

    Abookire, Alisa A.; Norcross, Brenda L.

    1998-01-01

    Three transects in Kachemak Bay, Alaska, were sampled in September 1994, May and August 1995, and February, May, and August 1996. Juvenile flathead sole, Hippoglossoides elassodon, and rock sole, Pleuronectes bilineatus, were the most abundant flatfishes, comprising 65-85% of all fiatfishes captured at any period. Collections of fish and sediments were made at regular depth contour intervals of l0 m. Habitat distribution was described by depth at 10 m increments and sediment percent weights of gravel, sand, and mud. Year-round habitat of flathead sole age-0 was primarily from 40 to 60 m, and age-1 habitat was primarily from 40 to 80 m. Summer habitat of rock sole age-0 and -1 was from 10 to 30 m, and in winter they moved offshore to depths of up to 150 m. Both age classes of flathead sole were most abundant on mixed mud sediments, while age-1 were also in high abundance on muddy sand sediments. Rock sole age-0 and -1 were most abundant on sand, though age-1 were also found on a variety of sediments both finer and coarser grained than sand. Flathead sole and rock sole had distinctive depth and sediment habitats. When habitat overlap occurred between the species, it was most often due to rock sole moving offshore in the winter. Abundances were not significantly different among seasons for age-1 flatfishes.

  6. San Francisco Bay Water Quality Improvement Fund

    Science.gov (United States)

    EPAs grant program to protect and restore San Francisco Bay. The San Francisco Bay Water Quality Improvement Fund (SFBWQIF) has invested in 58 projects along with 70 partners contributing to restore wetlands, water quality, and reduce polluted runoff.,

  7. kachemak_bay_ak.grd

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to...

  8. SF Bay Water Quality Improvement Fund: Projects and Accomplishments

    Science.gov (United States)

    San Francisco Bay Water Quality Improvement Fund (SFBWQIF) projects listed here are part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  9. Oceanographic conditions structure forage fishes into lipid-rich and lipid-poor communities in lower Cook Inlet, Alaska, USA

    Science.gov (United States)

    Abookire, Alisa A.; Piatt, John F.

    2005-01-01

    Forage fishes were sampled with a mid-water trawl in lower Cook Inlet, Alaska, USA, from late July to early August 1996 to 1999. We sampled 3 oceanographically distinct areas of lower Cook Inlet: waters adjacent to Chisik Island, in Kachemak Bay, and near the Barren Islands. In 163 tows using a mid-water trawl, 229 437 fishes with fork length lipid-poor gadids (walleye pollock and Pacific cod), and significantly increased in lipid-rich species such as Pacific sand lance, Pacific herring, and capelin. ?? Inter-Research 2005.

  10. Evidence for the existence of Persian Gulf Water and Red Sea Water in the Bay of Bengal

    Science.gov (United States)

    Jain, Vineet; Shankar, D.; Vinayachandran, P. N.; Kankonkar, A.; Chatterjee, Abhisek; Amol, P.; Almeida, A. M.; Michael, G. S.; Mukherjee, A.; Chatterjee, Meenakshi; Fernandes, R.; Luis, R.; Kamble, Amol; Hegde, A. K.; Chatterjee, Siddhartha; Das, Umasankar; Neema, C. P.

    2017-05-01

    The high-salinity water masses that originate in the North Indian Ocean are Arabian Sea High-Salinity Water (ASHSW), Persian Gulf Water (PGW), and Red Sea Water (RSW). Among them, only ASHSW has been shown to exist in the Bay of Bengal. We use CTD data from recent cruises to show that PGW and RSW also exist in the bay. The presence of RSW is marked by a deviation of the salinity vertical profile from a fitted curve at depths ranging from 500 to 1000 m; this deviation, though small (of the order of 0.005 psu and therefore comparable to the CTD accuracy of 0.003 psu), is an order of magnitude larger than the 0.0003 psu fluctuations associated with the background turbulence or instrument noise in this depth regime, allowing us to infer the existence of RSW throughout the bay. PGW is marked by the presence of a salinity maximum at 200-450 m; in the southwestern bay, PGW can be distinguished from the salinity maximum due to ASHSW because of the intervening Arabian Sea Salinity Minimum. This salinity minimum and the maximum associated with ASHSW disappear east and north of the south-central bay (85°E, 8°N) owing to mixing between the fresher surface waters that are native to the bay (Bay of Bengal Water or BBW) with the high-salinity ASHSW. Hence, ASHSW is not seen as a distinct water mass in the northern and eastern bay and the maximum salinity over most of the bay is associated with PGW. The surface water over most of the bay is therefore a mixture of ASHSW and the low-salinity BBW. As a corollary, we can also infer that the weak oxygen peak seen within the oxygen-minimum zone in the bay at a depth of 250-400 m is associated with PGW. The hydrographic data also show that these three high-salinity water masses are advected into the bay by the Summer Monsoon Current, which is seen to be a deep current extending to 1000 m. These deep currents extend into the northern bay as well, providing a mechanism for spreading ASHSW, PGW, and RSW throughout the bay.

  11. Spatial and temporal characterizations of water quality in Kuwait Bay.

    Science.gov (United States)

    Al-Mutairi, N; Abahussain, A; El-Battay, A

    2014-06-15

    The spatial and temporal patterns of water quality in Kuwait Bay have been investigated using data from six stations between 2009 and 2011. The results showed that most of water quality parameters such as phosphorus (PO4), nitrate (NO3), dissolved oxygen (DO), and Total Suspended Solids (TSS) fluctuated over time and space. Based on Water Quality Index (WQI) data, six stations were significantly clustered into two main classes using cluster analysis, one group located in western side of the Bay, and other in eastern side. Three principal components are responsible for water quality variations in the Bay. The first component included DO and pH. The second included PO4, TSS and NO3, and the last component contained seawater temperature and turbidity. The spatial and temporal patterns of water quality in Kuwait Bay are mainly controlled by seasonal variations and discharges from point sources of pollution along Kuwait Bay's coast as well as from Shatt Al-Arab River. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Relationships between precipitation and surface water chemistry in three Carolina bays

    International Nuclear Information System (INIS)

    Monegue, R.L.; Jagoe, C.H.

    1995-01-01

    Carolina Bays are shallow freshwater wetlands, the only naturally occurring lentic systems on the southeastern coastal plain. Bays are breeding sites for many amphibian species, but data on precipitation/surface water relationships and long-term chemical trends are lacking. Such data are essential to interpret major fluctuations in amphibian populations. Surface water and bulk precipitation were sampled bi-weekly for over two years at three bays along a 25 km transect on the Savannah River Site in South Carolina. Precipitation chemistry was similar at all sites; average pH was 4.56, and the major ions were H + (30.8 % of total), and SO 4 (50.3% of total). H + was positively correlated with SO 4 , suggesting the importance of anthropogenic acids to precipitation chemistry. All three bays, Rainbow Bay (RB), Thunder Bay (TB), and Ellenton Bay (EB), contained soft (specific conductivity 5--90 microS/cm), acidic water (pH 4.0--5.9) with DOM from 4--40 mg/L. The major cation for RB, TB, and EB, respectively, was: Mg (30.8 % of total); Na (27% of total); and Ca (34.2% of total). DOM was the major anion for all bays, and SO 4 represented 13 to 28 % of total anions. H + was not correlated to DOM or SO, in RB; H + was positively correlated to DOM and SO 4 in TB, and negatively correlated to DOM and SO 4 in EB. Different biogeochemical processes probably control pH and other chemical variables in each bay. While surface water H + was not directly correlated with precipitation H + , NO 3 , or SO 4 , precipitation and shallow groundwater are dominant water sources for these bays. Atmospheric inputs of anthropogenic acids and other chemicals are important factors influencing bay chemistry

  13. San Pablo Bay Tidal Marsh Enhancement and Water Quality Improvement Project

    Science.gov (United States)

    Information about the SFBWQP San Pablo Bay Tidal Marsh Enhancement and Water Quality Improvement Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  14. Water quality and discharge data for St. Joseph Bay, Florida, 1997-98

    Science.gov (United States)

    Berndt, M.P.; Franklin, M.A.

    1999-01-01

    Historical data were compiled on water quality and water levels for the St. Joseph Bay area to assess quality of possible sources of land-derived water into the Bay. Ground-water quality data were compiled from Florida Department of Environmental Protection and surface-water quality data were compiled from U.S.Geological Survey files. Water-quality and water-level data were measured during two sample collection periods in October 1997 and March 1998 to determine water-quality and discharge rates in St. Joseph Bay under two sets of flow conditions. Measurements in the Bay included water level, temperature, pH, specific conductance, dissolved oxygen, and turbidity. Median pH in water from the surficial, intermediate and Floridan aquifer systems ranged from 4.8 to 7.8, and median specific conductance values were less than 500 microsiemens per centimeter. Median nutrient concentrations-- nitrate plus nitrite, ammonia and phosphorus--in the three aquifers were less than 0.5 milligrams per liter. The median pH was 7.0 and the median specific conductance was 81 microsiemens per centimeter for two samples from the Chipola River distribution canal. Water level data were obtained for several wells near St. Joseph Bay but only two wells yielded sufficient data to plot hydrographs. Measurements in St. Joseph Bay during the October and March collection periods were similar for pH and turbidity but differed for temperature, specific conductance and dissolved oxygen. The median temperature was 20.6 degrees Celsius in October and 15.4 degrees Celsius in March, median specific conductance was 39,500 microsiemens per centimeter in October and 43,300 microsiemens per centimeter in March, and median dissolved oxygen was 7.6 milligrams per liter in October and 8.3 milligrams per liter in March. The range in water levels over a tidal cycle in St. Joseph Bay on October 29, 1997 was about 1 foot. During a 24-hour tidal cycle on October 29, 1997, estimated hourly discharge varied from

  15. Hydrodynamics and water quality models applied to Sepetiba Bay

    Science.gov (United States)

    Cunha, Cynara de L. da N.; Rosman, Paulo C. C.; Ferreira, Aldo Pacheco; Carlos do Nascimento Monteiro, Teófilo

    2006-10-01

    A coupled hydrodynamic and water quality model is used to simulate the pollution in Sepetiba Bay due to sewage effluent. Sepetiba Bay has a complicated geometry and bottom topography, and is located on the Brazilian coast near Rio de Janeiro. In the simulation, the dissolved oxygen (DO) concentration and biochemical oxygen demand (BOD) are used as indicators for the presence of organic matter in the body of water, and as parameters for evaluating the environmental pollution of the eastern part of Sepetiba Bay. Effluent sources in the model are taken from DO and BOD field measurements. The simulation results are consistent with field observations and demonstrate that the model has been correctly calibrated. The model is suitable for evaluating the environmental impact of sewage effluent on Sepetiba Bay from river inflows, assessing the feasibility of different treatment schemes, and developing specific monitoring activities. This approach has general applicability for environmental assessment of complicated coastal bays.

  16. 75 FR 13454 - Special Local Regulation, Fran Schnarr Open Water Championships, Huntington Bay, NY

    Science.gov (United States)

    2010-03-22

    ...-AA08 Special Local Regulation, Fran Schnarr Open Water Championships, Huntington Bay, NY AGENCY: Coast... navigable waters of Huntington Bay, New York due to the annual Fran Schnarr Open Water Championships. The..., ``Special Local Regulation, Fran Schnarr Open Water Championships, Huntington Bay, NY'' (Docket number USCG...

  17. 75 FR 38710 - Special Local Regulation, Fran Schnarr Open Water Championships, Huntington Bay, NY

    Science.gov (United States)

    2010-07-06

    ...-AA08 Special Local Regulation, Fran Schnarr Open Water Championships, Huntington Bay, NY AGENCY: Coast... Regulation on the navigable waters of Huntington Bay, New York due to the annual Fran Schnarr Open Water... ``Special Local Regulation, Fran Schnarr Open Water Championships, Huntington Bay, NY'' in the Federal...

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

    Science.gov (United States)

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

    2018-03-08

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

  19. Observations and a linear model of water level in an interconnected inlet-bay system

    Science.gov (United States)

    Aretxabaleta, Alfredo; Ganju, Neil K.; Butman, Bradford; Signell, Richard

    2017-01-01

    A system of barrier islands and back-barrier bays occurs along southern Long Island, New York, and in many coastal areas worldwide. Characterizing the bay physical response to water level fluctuations is needed to understand flooding during extreme events and evaluate their relation to geomorphological changes. Offshore sea level is one of the main drivers of water level fluctuations in semienclosed back-barrier bays. We analyzed observed water levels (October 2007 to November 2015) and developed analytical models to better understand bay water level along southern Long Island. An increase (∼0.02 m change in 0.17 m amplitude) in the dominant M2 tidal amplitude (containing the largest fraction of the variability) was observed in Great South Bay during mid-2014. The observed changes in both tidal amplitude and bay water level transfer from offshore were related to the dredging of nearby inlets and possibly the changing size of a breach across Fire Island caused by Hurricane Sandy (after December 2012). The bay response was independent of the magnitude of the fluctuations (e.g., storms) at a specific frequency. An analytical model that incorporates bay and inlet dimensions reproduced the observed transfer function in Great South Bay and surrounding areas. The model predicts the transfer function in Moriches and Shinnecock bays where long-term observations were not available. The model is a simplified tool to investigate changes in bay water level and enables the evaluation of future conditions and alternative geomorphological settings.

  20. Discharge, water-quality characteristics, and nutrient loads from McKay Bay, Delaney Creek, and East Bay, Tampa, Florida, 1991-1993

    Science.gov (United States)

    Stoker, Y.E.; Levesque, V.A.; Fritz, E.M.

    1996-01-01

    Nutrient enrichment in Tampa Bay has caused a decline in water quality in the estuary. Efforts to reduce the nutrient loading to Tampa Bay have resulted in improvement in water quality from 1981 to 1991. However, Tampa Bay still is onsidered enriched with nutrients. Water quality in East Bay (located at the northeastern part of Hillsborough Bay, which is an embayment in Tampa Bay) is not improving at the same rate as the rest of the bay. East Bay is the center of shipping activity in Tampa Bay and the seventh largest port in the United States. One of the primary cargoes is phosphate ore and related products such as fertilizer. The potential for nutrient loading to East Bay from shipping activities is high and has not previously been measured. Nitrogen and phosphorus loads from East Bay to Hillsborough Bay were measured during selected time periods during June 1992 through May 1993; these data were used to estimate seasonal and annual loads. These loads were evaluated to determine whether the loss of fertilizer products from shipping activities resulted in increased nutrient loading to Hillsborough Bay. Discharge was measured, and water-quality samples were collected at the head of East Bay (exiting McKay Bay), and at the mouth of East Bay. Discharge and nitrogen and phosphorus concentrations for the period June 1992 through May 1993 were used to compute loads. Discharges from McKay Bay, Delaney Creek, and East Bay are highly variable because of the effect of tide. Flow patterns during discharge measurements generally were unidirectional in McKay Bay and Delaney Creek, but more complex, bidirectional patterns were observed at the mouth of East Bay. Tidally affected discharge data were digitally filtered with the Godin filter to remove the effects of tide so that residual, or net, discharge could be determined. Daily mean discharge from McKay Bay ranged from -1,900 to 2,420 cubic feet per second; from Delaney Creek, -3.8 to 162 cubic feet per second; and from East

  1. Assessment for water quality by artificial neural network in Daya Bay, South China Sea.

    Science.gov (United States)

    Wu, Mei-Lin; Wang, You-Shao; Gu, Ji-Dong

    2015-10-01

    In this study, artificial neural network such as a self-organizing map (SOM) was used to assess for the effects caused by climate change and human activities on the water quality in Daya Bay, South China Sea. SOM has identified the anthropogenic effects and seasonal characters of water quality. SOM grouped the four seasons as four groups (winter, spring, summer and autumn). The Southeast Asian monsoons, northeasterly from October to the next April and southwesterly from May to September have also an important influence on the water quality in Daya Bay. Spatial pattern is mainly related to anthropogenic activities and hydrodynamics conditions. In spatial characteristics, the water quality in Daya Bay was divided into two groups by chemometrics. The monitoring stations (S3, S8, S10 and S11) were in these area (Dapeng Ao, Aotou Harbor) and northeast parts of Daya Bay, which are areas of human activity. The thermal pollution has been observed near water body in Daya Bay Nuclear Power Plant (S5). The rest of the monitoring sites were in the south, central and eastern parts of Daya Bay, which are areas that experience water exchanges from South China Sea. The results of this study may provide information on the spatial and temporal patterns in Daya Bay. Further research will be carry out more research concerning functional changes in the bay ecology with respect to changes in climatic factor, human activities and bay morphology in Daya Bay.

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

    Science.gov (United States)

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

    2014-01-01

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

  3. 27 CFR 20.102 - Bay rum, alcoholado, or alcoholado-type toilet waters.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bay rum, alcoholado, or alcoholado-type toilet waters. 20.102 Section 20.102 Alcohol, Tobacco Products and Firearms ALCOHOL AND... alcoholado-type toilet waters. All bay rum, alcoholado, or alcoholado-type toilet waters made with specially...

  4. Cumulative impacts of hydroelectric development on the fresh water balance in Hudson Bay

    International Nuclear Information System (INIS)

    Anctil, F.; Couture, R.

    1994-01-01

    A study is presented of the impacts of hydroelectric development on the surface water layer of Hudson Bay, including James Bay and the Foxe Basin. These impacts are directly related to the modifications in the fresh water balance of Hudson Bay and originate from the management of hydroelectric complexes. The fresh water balance is determined by identifying, at different scales, the modifications caused by each complex. The main inputs are the freezing and thawing of the ice cover, runoff water, and mass exchange at the air-water interface. Three spatial scales were used to obtain the resolution required to document the cumulative effects of fresh water balance modifications on the water surface layer, one each for Hudson Bay, Hudson Strait, and the Labrador Sea. Finally, the addition of the proposed Great Whale hydroelectric complex is examined from the available information and forecasts. 18 refs,. 6 figs., 1 tab

  5. Spatial patterning of water quality in Biscayne Bay, Florida as a function of land use and water management.

    Science.gov (United States)

    Caccia, Valentina G; Boyer, Joseph N

    2005-11-01

    An objective classification analysis was performed on a water quality data set from 25 sites collected monthly during 1994-2003. The water quality parameters measured included: TN, TON, DIN, NH4+, NO3-, NO2-, TP, SRP, TN:TP ratio, TOC, DO, CHL A, turbidity, salinity and temperature. Based on this spatial analysis, Biscayne Bay was divided into five zones having similar water quality characteristics. A robust nutrient gradient, driven mostly by dissolved inorganic nitrogen, from alongshore to offshore in the main Bay, was a large determinant in the spatial clustering. Two of these zones (Alongshore and Inshore) were heavily influenced by freshwater input from four canals which drain the South Dade agricultural area, Black Point Landfill, and sewage treatment plant. The North Bay zone, with high turbidity, phytoplankton biomass, total phosphorus, and low DO, was affected by runoff from five canals, the Munisport Landfill, and the urban landscape. The South Bay zone, an embayment surrounded by mangrove wetlands with little urban development, was high in dissolved organic constituents but low in inorganic nutrients. The Main Bay was the area most influenced by water exchange with the Atlantic Ocean and showed the lowest nutrient concentrations. The water quality in Biscayne Bay is therefore highly dependent of the land use and influence from the watershed.

  6. Shallow-water Benthic Habitats in Jobos Bay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Shallow-water (<30m) benthic habitat maps of the nearshore marine environment of Jobos Bay, Puerto Rico were mapped and characterized using visual interpretation...

  7. San Francisco Bay Water Quality Improvement Fund Points, SF Bay CA, 2015, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  8. Water quality of Tampa Bay, Florida, June 1972-May 1976

    Science.gov (United States)

    Goetz, Carole L.; Goodwin, Carl R.

    1980-01-01

    A comprehensive assessment of the water quality of Tampa Bay, Florida, was initiated in 1970 to provide background information to evaluate the effects of widening and deepening the ship channel to the port of Tampa. This report provides results of water-quality sampling in the bay from 1972 to 1976, prior to dredging. Measurements of temperature, dissolved oxygen, pH, turbidity, specific conductance, biochemical oxygen demand, and total organic carbon were made as well as measurements for several nutrient, metal, and pesticide parameters. Many parameters were measured at as many as three points in the vertical. These data indicate that Tampa Bay is well-mixed vertically with little density stratification. Time histories of average temperature, dissolved oxygen, pH, turbidity, specific conductance and nutrient values within four subareas of Tampa Bay are given to reveal seasonal or other trends during the period of record. Temperature, dissolved oxygen, pH, turbidity, specific conductance, nutrient, biochemical oxygen demand, total organic carbon, and metal data are also presented as areal distributions. Nutrient concentrations were generally higher in Hillsborough Bay than in other sub-areas of Tampa Bay. Biochemical oxygen demand, total organic carbon, and total organic nitrogen distribution patterns show regions of highest concentrations to be along bay shorelines near population centers. Of the metals analyzed, all were present in concentrations of less than 1 milligram per liter. (USGS)

  9. Application of a circulation model in waters, based in the difference method, for bays

    International Nuclear Information System (INIS)

    Rosa, P.A.C.

    1985-01-01

    The Knowledge of circulation of water in bays, in addition to the possibility of simulation future conditions, can be of great interest in solving problems related to the cooling water for Nuclear Power Plants, study of sediments and water polution, in addition to the study of civil engineering works planned in bays. A Numerical Circulation Model of water in bays, is applied to the conditions of Sepetiba Bay at Rio de Janeiro coast. This System of Partial Differential Equations that constitute the Model, were solved by the Finite Difference Method, using a uniform cartesian grid for uniform time steps generating a bi-dimensional flow measurement of depth. The results obtained by comparing the values of the Model and measurements taken a bay were satisfactory, assuring its credibility and efficiency. A programming code was developed for the application providing outputing at any preditermined time steps, with discrimination of 30 seconds, the average levels, flows, velocities and depths of water of each grid spacing along the length of the bay in addition to a graphic of the flow. (Author) [pt

  10. Flow in water-intake pump bays: A guide for utility engineers. Final report

    International Nuclear Information System (INIS)

    Ettema, R.

    1998-09-01

    This report is intended to serve as a guide for power-plant engineers facing problems with flow conditions in pump bays in water-intake structures, especially those located alongside rivers. The guide briefly introduces the typical prevailing flow field outside of a riverside water intake. That flow field often sets the inflow conditions for pump bays located within the water intake. The monograph then presents and discusses the main flow problems associated with pump bays. The problems usually revolve around the formation of troublesome vortices. A novel feature of this monograph is the use of numerical modeling to reveal diagnostically how the vortices form and their sensitivities to flow conditions, such as uniformity of approach flow entering the bay and water-surface elevation relative to pump-bell submergence. The modeling was carried out using a computer code developed specially for the present project. Pump-bay layouts are discussed next. The discussion begins with a summary of the main variables influencing bay flows. The numerical model is used to determine the sensitivities of the vortices to variations in the geometric parameters. The fixes include the use of flow-control vanes and suction scoops for ensuring satisfactory flow performance in severe flow conditions; notably flows with strong cross flow and shallow flows. The monograph ends with descriptions of modeling techniques. An extensive discussion is provided on the use of numerical model for illuminating bay flows. The model is used to show how fluid viscosity affects bay flow. The effect of fluid viscosity is an important consideration in hydraulic modeling of water intakes

  11. Effects of waves on water dispersion in a semi-enclosed estuarine bay

    Science.gov (United States)

    Delpey, M. T.; Ardhuin, F.; Otheguy, P.

    2012-04-01

    The bay of Saint Jean de Luz - Ciboure is a touristic destination located in the south west of France on the Basque coast. This small bay is 1.5km wide for 1km long. It is semi-enclosed by breakwaters, so that the area is mostly protected from waves except in its eastern part, where wave breaking is regularly observed over a shallow rock shelf. In the rest of the area the currents are generally weak. The bay receives fresh water inflows from two rivers. During intense raining events, the rivers can introduce pollutants in the bay. The input of pollutants combined with the low level dynamic of the area can affect the water quality for several days. To study such a phenomenon, mechanisms of water dispersion in the bay are investigated. The present paper focuses on the effects of waves on bay dynamics. Several field experiments were conducted in the area, combining wave and current measurements from a set of ADCP and ADV, lagrangian difter experiments in the surfzone, salinity and temperature profile measurements. An analysis of this set of various data is provided. It reveals that the bay combines remarkable density stratification due to fresh water inflows and occasionally intense wave-induced currents in the surfzone. These currents have a strong influence on river plume dynamics when the sea state is energetic. Moreover, modifications of hydrodynamics in the bay passes are found to be remarkably correlated with sea state evolutions. This result suggests a significant impact of waves on the bay flushing. To further analyse these phenomena, a three dimensional numerical model of bay hydrodynamics is developed. The model aims at reproducing fresh water inflows combined with wind-, tide- and wave-induced currents and mixing. The model of the bay is implemented using the code MOHID , which has been modified to allow the three dimensional representation of wave-current interactions proposed by Ardhuin et al. [2008b] . The circulation is forced by the wave field modelled

  12. Risk assessment for produced water discharges to Louisiana Open Bays

    Energy Technology Data Exchange (ETDEWEB)

    Meinhold, A.F.; DePhillips, M.P.; Holtzman, S.

    1995-06-23

    Data were collected prior to termination of discharge at three sites (including two open bay sites at Delacroix Island and Bay De Chene) for the risk assessments. The Delacroix Island Oil and Gas Field has been in production since the first well drilling in 1940; the Bay De Chene Field, since 1942. Concentrations of 226Ra, 228Ra, 210Po, and 228Th were measured in discharges. Radium conc. were measured in fish and shellfish tissues. Sediment PAH and metal conc. were also available. Benthos sampling was conducted. A survey of fishermen was conducted. The tiered risk assessment showed that human health risks from radium in produced water appear to be small; ecological risk from radium and other radionuclides in produced water also appear small. Many of the chemical contaminants discharged to open Louisiana bays appear to present little human health or ecological risk. A conservative screening analysis suggested potential risks to human health from Hg and Pb and a potential risk to ecological receptors from total effluent, Sb, Cd, Cu, Pb, Ni, Ag, Zn, and phenol in the water column and PAHs in sediment; quantitiative risk assessments are being done for these contaminants.

  13. Water quality in South San Francisco Bay, California: current condition and potential issues for the South Bay Salt Pond Restoration Project.

    Science.gov (United States)

    Grenier, J Letitia; Davis, Jay A

    2010-01-01

    The SBSPRP is an extensive tidal wetland restoration project that is underway at the margin of South San Francisco Bay, California. The Project, which aims to restore former salt ponds to tidal marsh and manage other ponds for water bird support, is taking place in the context of a highly urbanized watershed and an Estuary already impacted by chemical contaminants. There is an intimate relationship between water quality in the watershed, the Bay, and the transitional wetland areas where the Project is located. The Project seeks to restore habitat for endangered and endemic species and to provide recreational opportunities for people. Therefore, water quality and bioaccumulation of contaminants in fish and wildlife is an important concern for the success of the Project. Mercury, PCBs, and PBDEs are the persistent contaminants of greatest concern in the region. All of these contaminants are present at elevated concentrations both in the abiotic environment and in wildlife. Dioxins, pyrethroids, PAHs, and selenium are also problematic. Organochlorine insecticides have historically impacted the Bay, and they remain above thresholds for concern in a small proportion of samples. Emerging contaminants, such as PFCs and non-PBDE flame retardants, are also an important water quality issue. Beyond chemical pollutants, other concerns for water quality in South San Francisco Bay exist, and include biological constituents, especially invasive species, and chemical attributes, such as dissolved oxygen and salinity. Future changes, both from within the Project and from the Bay and watershed, are likely to influence water quality in the region. Project actions to restore wetlands could worsen, improve, or not affect the already impaired water quality in South Bay. Accelerated erosion of buried sediment as a consequence of Project restoration actions is a potentially serious regional threat to South Bay water and sediment quality. Furthermore, the planned restoration of salt ponds

  14. Hydrogeologic setting and ground water flow beneath a section of Indian River Bay, Delaware

    Science.gov (United States)

    Krantz, David E.; Manheim, Frank T.; Bratton, John F.; Phelan, Daniel J.

    2004-01-01

    The small bays along the Atlantic coast of the Delmarva Peninsula (Delaware, Maryland, and Virginia) are a valuable natural resource, and an asset for commerce and recreation. These coastal bays also are vulnerable to eutrophication from the input of excess nutrients derived from agriculture and other human activities in the watersheds. Ground water discharge may be an appreciable source of fresh water and a transport pathway for nutrients entering the bays. This paper presents results from an investigation of the physical properties of the surficial aquifer and the processes associated with ground water flow beneath Indian River Bay, Delaware. A key aspect of the project was the deployment of a new technology, streaming horizontal resistivity, to map the subsurface distribution of fresh and saline ground water beneath the bay. The resistivity profiles showed complex patterns of ground water flow, modes of mixing, and submarine ground water discharge. Cores, gamma and electromagnetic-induction logs, and in situ ground water samples collected during a coring operation in Indian River Bay verified the interpretation of the resistivity profiles. The shore-parallel resistivity lines show subsurface zones of fresh ground water alternating with zones dominated by the flow of salt water from the estuary down into the aquifer. Advective flow produces plumes of fresh ground water 400 to 600 m wide and 20 m thick that may extend more than 1 km beneath the estuary. Zones of dispersive mixing between fresh and saline ground water develop on the upper, lower, and lateral boundaries of the the plume. the plumes generally underlie small incised valleys that can be traced landward to stream draining the upland. The incised valleys are filled with 1 to 2 m of silt and peat that act as a semiconfining layer to restrict the downward flow of salt water from the estuary. Active circulation of both the fresh and saline ground water masses beneath the bay is inferred from the geophysical

  15. 33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York. 100.124 Section 100.124 Navigation and Navigable... NAVIGABLE WATERS § 100.124 Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York...

  16. Appearance and water quality of turbidity plumes produced by dredging in Tampa Bay, Florida

    Science.gov (United States)

    Goodwin, Carl R.; Michaelis, D.M.

    1984-01-01

    Turbidity plumes in Tampa Bay, Florida, produced during ship-channel dredging operations from February 1977 to August 1978, were monitored in order to document plume appearance and water quality, evaluate plume influence on the characteristics of Tampa Bay water, and provide a data base for comparison with other areas that have similar sediment, dredge, placement, containment, and tide conditions. The plumes investigated originated from the operation of one hopper dredge and three cutterhead-pipeline dredges. Composition of bottom sediment was found to vary from 85 percent sand and shell fragments to 60 percent silt and clay. Placement methods for dredged sediment included beach nourishment, stationary submerged discharge, oscillating surface discharge, and construction of emergent dikes. Tidal currents ranged from slack water to flow velocities of 0.60 meter per second. Plumes were monitored simultaneously by (1) oblique and vertical 35-millimeter aerial photography and (2) water-quality sampling to determine water clarity and concentrations of nutrients, metals, pesticides, and industrial compounds. Forty-nine photographs depict plumes ranging in length from a few tens of meters to several kilometers and ranging in turbidity level from hopper-dredge unloading operations also produced plumes of low visibility. Primary turbidity plumes were produced directly by dredging and placement operations; secondary plumes were produced indirectly by resuspension of previously deposited material. Secondary plumes were formed both by erosion, in areas of high-velocity tidal currents, and by turbulence from vessels passing over fine material deposited in shallow areas. Where turbidity barriers were not used, turbidity plumes visible at the surface were good indicators of the location of turbid water at depth. Where turbidity barriers were used, turbid bottom water was found at locations having no visible surface plumes. A region of rapidly accelerating then decelerating flow

  17. Variations in water clarity and bottom albedo in Florida Bay from 1985 to 1997

    Science.gov (United States)

    Stumpf, R.P.; Frayer, M.L.; Durako, M.J.; Brock, J.C.

    1999-01-01

    Following extensive seagrass die-offs of the late 1980s and early 1990s, Florida Bay reportedly had significant declines in water clarity due to turbidity and algal blooms. Scant information exists on the extent of the decline, as this bay was not investigated for water quality concerns before the die-offs and limited areas were sampled after the primary die-off. We use imagery from the Advanced Very High Resolution Radiometer (AVHRR) to examine water clarity in Florida Bay for the period 1985 to 1997. The AVHRR provides data on nominal water reflectance and estimated fight attenuation, which are used here to describe turbidity conditions in the bay on a seasonal basis. In situ observations on changes in seagrass abundance within the bay, combined with the satellite data, provide additional insights into losses of seagrass. The imagery shows an extensive region to the west of Florida Bay having increased reflectance and fight attenuation in both winter and summer beginning in winter of 1988. These increases are consistent with a change from dense seagrass to sparse or negligible cover. Approximately 200 km2 of these offshore seagrasses may have been lost during the primary die-off (1988 through 1991), significantly more than in the bay. The imagery shows the distribution and timing of increased turbidity that followed the die-offs in the northwestern regions of the bay, exemplified in Rankin Lake and Johnson Key Basin, and indicates that about 200 km2 of dense seagrass may have been lost or severely degraded within the bay from the start of the die-off. The decline in water clarity has continued in the northwestern bay since 1991. The area west of the Everglades National Park boundaries has shown decreases in both winter turbidity and summer reflectances, suggestive of partial seagrass recovery. Areas of low reflectance associated with a major Syringodium filiforme seagrass meadow north of Marathon (Vaca Key, in the Florida Keys) appear to have expanded westward

  18. Ecosystem under pressure: ballast water discharge into Galveston Bay, Texas (USA) from 2005 to 2010.

    Science.gov (United States)

    Steichen, Jamie L; Windham, Rachel; Brinkmeyer, Robin; Quigg, Antonietta

    2012-04-01

    Ballast water exchange processes facilitate the dispersal and unnatural geographic expansion of phytoplankton, including harmful algal bloom species. From 2005 to 2010, over 45,000 vessels (≈ 8000 annually) travelled across Galveston Bay (Texas, USA) to the deep-water ports of Houston (10th largest in the world), Texas City and Galveston. These vessels (primarily tankers and bulkers) discharged ≈ 1.2 × 10(8) metrictons of ballast water; equivalent to ≈ 3.4% of the total volume of the Bay. Over half of the ballast water discharged had a coastwise origin, 96% being from US waters. Galveston Bay has fewer non-indigenous species but receives a higher volume of ballast water discharge, relative to the highly invaded Chesapeake and San Francisco Bays. Given the magnitude of shipping traffic, the role of Galveston Bay, both as a recipient and donor region of non-indigenous phytoplankton species is discussed here in terms of the invasibility risk to this system by way of ballast water. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Hypoxia in Korean Coastal Waters: A Case Study of the Natural Jinhae Bay and Artificial Shihwa Bay

    Directory of Open Access Journals (Sweden)

    Jiyoung Lee

    2018-03-01

    Full Text Available Several coastal regions in Korea have suffered from hypoxia since the 1970s. We present the first review of Korean coastal hypoxia, focusing on its spatiotemporal variation, controlling factors, and effects on marine ecosystems. The review considers the two hotspots of the natural Jinhae Bay (JB and artificial Shihwa Bay (SB, which are referred to as “Korean dead zones.” The hypoxia in the JB is attributed to eutrophication due to domestic and land-used waste input and thermal stratification based on the naturally sluggish water circulation, whereas the hypoxia in the SB is due to eutrophication resulting from domestic, land-used, and industrial waste input and haline stratification as a consequence of the artificially created water stagnation. The bottom-water hypoxia and stratification has led to an imbalance in nitrogen:phosphorus ratio between surface and bottom waters. Hypoxia has also created undesirable benthic community changes in the both bays: (1 mass mortality of large species and recolonization with elevated abundances of opportunists in JB, and (2 decrease of the number of species, abundance, and diversity of benthic communities in SB. Therefore, it behooves us to pay attention to these environmental changes. This review will be helpful in determining the direction of future studies of Korean coastal hypoxia.

  20. Water renewal in Montevideo's bay: a two compartments model for tritium kinetics

    International Nuclear Information System (INIS)

    Suarez-Antola, Roberto

    2013-01-01

    During field work about dynamics and renewal of water in Montevideo's Bay, 100 Ci of tritiated water were evenly distributed in the north-east region of the bay, by a continuous injection of a solution, during 5 hours, from a 200 litres tank, using a peristaltic pump. The whole bay was divided in 20 concentration cells, taking into account available bathymetric charts and corrections from field data obtained in situ. Tritium concentrations (activities per unit volume) and other relevant parameters (temperature, electrical conductivity, etc.) were measured in vertical profiles during three weeks, in the mid-point of each cell, first twice a day and the on a daily basis. Remnant total tritium activity was estimated from cells volumes and midpoint cells activity concentrations. Consistency checks were done. A one compartment model was used to estimate a global renewal time of circa 29 hours. However, the details of the measured tritium kinetics, a careful consideration of bathymetric data, water movements in a tidal environment (measured with drogues, fluorescent tracers and current meters), as well as the results of computer fluid dynamics modelling (in depth averaged) suggests that the bay can be meaningfully divided in two main compartments: a North-East and a South-West compartment. The purpose of this paper is threefold: (1) to describe the construction of a two compartments model for water renewal in Montevideo's Bay, (2) to apply experimental data of tritium kinetics to estimate the parameters of the model, and (3) to discuss the validity of the model and its practical applicability. The meaning of the renewal time of each compartment and its relation with the measured tritium kinetics in each cell is discussed. The perturbations in water circulation and renewal produced by civil works already done or the perturbations that could be expected due to civil works to be done, in relation with Montevideo's harbour, is discussed. The tracer model, jointly with other

  1. Water quality dynamics in an urbanizing subtropical estuary(Oso Bay, Texas).

    Science.gov (United States)

    Wetz, Michael S; Hayes, Kenneth C; Fisher, Kelsey V B; Price, Lynn; Sterba-Boatwright, Blair

    2016-03-15

    Results are presented from a study of water quality dynamics in a shallow subtropical estuary, Oso Bay, Texas, which has a watershed that has undergone extensive urbanization in recent decades. High inorganic nutrient, dissolved organic matter and chlorophyll concentrations, as well as low pH (Oso Bay that receives wastewater effluent. Despite being shallow (Oso Bay, suggesting that it may be exported to adjacent Corpus Christi Bay and contribute to seasonal hypoxia development in that system as well. These results argue for wastewater nutrient input reductions in order to alleviate the symptoms of eutrophication. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. 77 FR 75017 - Security Zone; On the Waters in Kailua Bay, Oahu, HI

    Science.gov (United States)

    2012-12-19

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket Number USCG-2012-1038] RIN 1625-AA87 Security Zone; On the Waters in Kailua Bay, Oahu, HI AGENCY: Coast Guard, DHS. ACTION... to read as follows: Sec. 165.T14-215 Security Zone; On the Waters in Kailua Bay, Oahu, HI. (a...

  3. Distribution of perfluoroalkyl compounds in Osaka Bay and coastal waters of Western Japan.

    Science.gov (United States)

    Beškoski, Vladimir P; Yamamoto, Katsuya; Yamamoto, Atsushi; Okamura, Hideo; Hayashi, Mitsuru; Nakano, Takeshi; Matsumura, Chisato; Fukushi, Keiichi; Wada, Shinpei; Inui, Hideyuki

    2017-03-01

    Perfluoroalkyl acids (PFAAs) including perfluoroalkyl sulfonates (PFSAs) and perfluoroalkyl carboxylates (PFCAs) were analyzed in sediment samples taken from Ajifu Waterway in Osaka city, from Osaka Bay, and from Kagoshima Bay, as well as in fifteen seawater samples collected from Osaka Bay and coastal waters of Western Japan. In all sediment samples, only PFCAs were detected, and the highest concentration was determined in Ajifu Waterway, where ΣPFAA was 58990 ng kg -1 dry weight. The total concentrations of PFAAs in sea water samples ranged between the limit of quantification and 53.4 ng L -1 , and perfluorohexanoic acid was the most prevalent and had the highest concentration of 37 ng L -1 . The changes in the patterns and concentrations of PFAAs in Osaka Bay and coastal waters of Western Japan indicate that the PFAAs in surface waters are influenced by sources from Keihanshin Metropolitan Area, mainly the Yodo River basin, and the dilution effect which naturally occurs during their transport to the Pacific Ocean. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Abdul Rozak

    2007-04-01

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

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

    Science.gov (United States)

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

    1992-05-01

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

  6. 76 FR 9709 - Water Quality Challenges in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary

    Science.gov (United States)

    2011-02-22

    ... Water Quality Challenges in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary AGENCY... the San Francisco Bay/ Sacramento-San Joaquin Delta Estuary (Bay Delta Estuary) in California. EPA is... programs to address recent significant declines in multiple aquatic species in the Bay Delta Estuary. EPA...

  7. Long-Term Water Temperature Variations in Daya Bay, China Using Satellite and In Situ Observations

    Directory of Open Access Journals (Sweden)

    Jing Yu

    2010-01-01

    Full Text Available Daya Bay is a shallow, semi-en closed bay in the northern section of the South China Sea. The present study analyzed variations of water temperature in Daya Bay over the past 21 years (1985 - 2005 using Advanced Very High Resolution Radiometer (AVHRR satellite remote sensing data and in situ observations. Results showed that AVHRR readings of sea surface temperature (SST increased by 0.07°C y-1. Linear regression anal y sis for monthly SST anomalies (SSTA showed a shift from negative to positive from 1995 - 1996, when the Daya Bay nuclear power station commenced operations in 1994. The slope of linear regression analysis for SSTA nearly doubled from 0.05 (1985 - 1993 to 0.09 (1994 - 2005. Monthly AVHRR images showed a thermal plume from the power station and revealed the in crease of SST over 21 years. In situ observations in water temperature also showed an in creasing trend for the same period (1985 - 2005. Variations in water temperature in Daya Bay were connected with climatic perturbations and in creasing human activity including thermal discharge from nuclear power stations and the rapid economic development around the bay area.

  8. 33 CFR 100.919 - International Bay City River Roar, Bay City, MI.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false International Bay City River Roar, Bay City, MI. 100.919 Section 100.919 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Bay City River Roar, Bay City, MI. (a) Regulated Area. A regulated area is established to include all...

  9. Kachemak Bay, Alaska Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated...

  10. Monitoring coastal water properties and current circulation with ERTS-1. [Delaware Bay

    Science.gov (United States)

    Klemas, V.; Otley, M.; Wethe, C.; Rogers, R.

    1974-01-01

    Imagery and digital tapes from nine successful ERTS-1 passes over Delaware Bay during different portions of the tidal cycle have been analyzed with special emphasis on turbidity, current circulation, waste disposal plumes and convergent boundaries between different water masses. ERTS-1 image radiance correlated well with Secchi depth and suspended sediment concentration. Circulation patterns observed by ERTS-1 during different parts of the tidal cycle, agreed well with predicted and measured currents throughout Delaware Bay. Convergent shear boundaries between different water masses were observed from ERTS-1. In several ERTS-1 frames, waste disposal plumes have been detected 36 miles off Delaware's Atlantic coast. The ERTS-1 results are being used to extend and verify hydrodynamic models of the bay, developed for predicting oil slick movement and estimating sediment transport.

  11. Dissolved oxygen content as an index of water quality in San Vicente Bay, Chile (36 degrees 45'S).

    Science.gov (United States)

    Rudolph, Anny; Ahumada, Ramón; Pérez, Claudio

    2002-08-01

    The present report describes some effects of industrial and municipal effluents on the waters of San Vicente Bay. Analyses of the main substances contained in the fishing industry effluent suggest rating criteria based on the oxygen saturation of the water as an assessment of organic pollution. Six cruises were carried out throughout the Bay, from June to December 1996. Water samples were analyzed for dissolved oxygen, oil and grease content, and sediment samples for organic matter content. Water parameters (salinity, temperature) were used to characterize the Bay's hydrography, and to calculate values for oxygen saturation. The measurements demonstrated a local broad range of oxygen deficit, with a maximum of 45% in the winter to 95% in the spring. In November more than 65% of the Bay's area showed oxygen deficits greater than 40%. Organic matter was unusually high in sediments along the northern sector of the Bay. The results suggest that the oxygen depletion was a representative parameter for establishing a relative scale of water quality in this Bay.

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

    Science.gov (United States)

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

    2017-12-01

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

  13. Change of water environment in the inner bay in consideration of heat balance

    International Nuclear Information System (INIS)

    Wada, Akira; Miyaike, Katsuto

    1983-01-01

    The study on the effect of warm water discharged from large capacity thermal and nuclear power stations on the local climate around the power stations is necessary for promoting the development of power resources in harmony with natural environment. In this study, Mikawa Bay was selected as the object of research, and the simulation analysis of water temperature was carried out by the water column model, based on the result of analysis of the local weather and sea observation data. Thus, the amount of heat exchange between the atmosphere and sea water in natural sea area was grasped, and how the change in the amount of heat exchange when the thermal load due to warm water discharge was imposed is ranked in natural sea environment was examined. The variation of surface water temperature in Mikawa Bay tended to be large in summer and small in winter. It was clarified that the factor controlling the water temperature in the bay was the variation of climatic factors. In the sea area where the effect of open sea water was relatively small, the variation of water temperature was able to be expressed by the water column model. The change in the amount of heat exchange in the range of warm water diffusion with 2 deg C temperature rise was determined. (Kato, I.)

  14. Three-dimensional distributions of sewage markers in Tokyo Bay water-fluorescent whitening agents (FWAs)

    International Nuclear Information System (INIS)

    Managaki, Satoshi; Takada, Hideshige; Kim, Dong-Myung; Horiguchi, Toshihiro; Shiraishi, Hiroaki

    2006-01-01

    Three-dimensional distributions of fluorescent whitening agents (FWAs: more specifically, DSBP and DAS1), which are sewage-derived water-soluble markers, were observed in Tokyo Bay water through multi-layer sampling of water at 20 locations. In summer, FWAs predominated in the surface layers, with trace but significant concentration of FWAs in bottom water due to stratification of seawater. In winter, on the other hand, FWAs were extensively mixed into the bottom layers because of the vertical mixing of seawater. In the surface layer, FWA concentrations and the DSBP/DAS1 ratio (the concentration ratio of DSBP to DAS1) were lower in summer than in winter, suggesting more efficient photodegradation of FWAs in euphotic zones during the summer due to stronger solar radiation. Horizontally, FWAs were widely distributed over the surface layer of Tokyo Bay. Surface water with DSBP concentrations above 50 ng/L, corresponding to <200 times dilution of sewage effluent, was found to have spread up to 10 km from the coastline. In addition, an offshore decline in FWA concentrations was observed, showing a half-distance of 10-20 km. The decrease was caused by dilution by seawater of fresh water containing FWAs. The eastern part of the bay was different with respect to surface layers, with higher concentrations seen in northeastern parts. Furthermore, dispersion of combined sewer overflow (CSO)-derived water mass was observed in Tokyo Bay after heavy rain

  15. Muon reconstruction in the Daya Bay water pools

    International Nuclear Information System (INIS)

    Hackenburg, R. W.

    2017-01-01

    Muon reconstruction in the Daya Bay water pools would serve to verify the simulated muon fluxes and offer the possibility of studying cosmic muons in general. This reconstruction is, however, complicated by many optical obstacles and the small coverage of photomultiplier tubes (PMTs) as compared to other large water Cherenkov detectors. The PMTs’ timing information is useful only in the case of direct, unreflected Cherenkov light. This requires PMTs to be added and removed as an hypothesized muon trajectory is iteratively improved, to account for the changing effects of obstacles and direction of light. Therefore, muon reconstruction in the Daya Bay water pools does not lend itself to a general fitting procedure employing smoothly varying functions with continuous derivatives. Here, we describe an algorithm which overcomes these complications. It employs the method of Least Mean Squares to determine an hypothesized trajectory from the PMTs’ charge-weighted positions. This initially hypothesized trajectory is then iteratively refined using the PMTs’ timing information. Reconstructions with simulated data reproduce the simulated trajectory to within about 5° in direction and about 45 cm in position at the pool surface, with a bias that tends to pull tracks away from the vertical by about 3°.

  16. Water characteristics, mixing and circulation in the Bay of Bengal during southwest monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, V.S.N.; Sarma, Y.V.B.; Rao, D.P.; Murty, C.S.

    in the western, central and southeastern regions of the Bay respectively. The wind-stress-curl-induced upwelling effect is confined to depth limits of 50-100 m as is supportEd. by a band of cold (24 degrees -19 degrees C) water in the central Bay. In the southern...

  17. Iodate in inshore and offshore waters of Central Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.

    Biological stripping of iodate in the surface waters is noticed in the inshore and offshore waters of Bay of Bengal. A good correlation is observed between iodate and phosphate and nitrate and the molar ratios determined being NO3: PO4: IO3 = 88...

  18. 33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. 162.125 Section 162.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.125 Sturgeon Bay and the Sturgeon Bay Ship...

  19. Optical investigations of CDOM-rich coastal waters in Pärnu Bay

    Directory of Open Access Journals (Sweden)

    Birgot Paavel

    2011-06-01

    Full Text Available Pärnu Bay in the Eastern Baltic Sea was chosen for studying the spatial-temporal variability of water parameters as an optically complex and semi-enclosed coastal area. The water properties of Pärnu Bay are influenced by the town of Pärnu with its 70 000 inhabitants and by the high inflow from the Pärnu River. The in situ database was collected during the ice-free period of 2006–2007 (11 sampling stations, 10 series of field trips. According to the results, the main factor influencing the light attenuation in the water was coloured dissolved organic matter (CDOM which overshadows the relationships between the radiation characteristics and organic/inorganic particles. In April and May, when the freshwater discharge of the Pärnu River was highest, the values of aCDOM(380 were between 4.6 and 31.8 m–1, while in September they varied only within 2.52–10.2 m–1. The concentrations of chlorophyll a (including its metabolite phaeophytin a generally ranged from 4 to 12 mg m–3 but during algal blooms they rapidly increased to 31.8 mg m–3. The temporal and spatial irregularity of suspended matter concentrations was caused by the loading of unpacked peat at the Pärnu River mouth as well as by undulation and ship traffic in Pärnu Bay. MODIS level 1 data with 250 m resolution were used for illustrative comparison of spatial and temporal variations in the water properties in Pärnu Bay and the Gulf of Riga. An attempt to perform the quantitative analysis with the purpose of estimating the concentrations of different optically significant substances separately gave statistically incorrect results.

  20. 33 CFR 334.778 - Pensacola Bay and waters contiguous to the Naval Air Station, Pensacola, FL; restricted area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pensacola Bay and waters... Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.778 Pensacola Bay and waters contiguous to the Naval Air Station, Pensacola...

  1. Investigation of Spatial and Temporal Trends in Water Quality in Daya Bay, South China Sea

    Science.gov (United States)

    Wu, Mei-Lin; Wang, You-Shao; Dong, Jun-De; Sun, Cui-Ci; Wang, Yu-Tu; Sun, Fu-Lin; Cheng, Hao

    2011-01-01

    The objective is to identify the spatial and temporal variability of the hydrochemical quality of the water column in a subtropical coastal system, Daya Bay, China. Water samples were collected in four seasons at 12 monitoring sites. The Southeast Asian monsoons, northeasterly from October to the next April and southwesterly from May to September have also an important influence on water quality in Daya Bay. In the spatial pattern, two groups have been identified, with the help of multidimensional scaling analysis and cluster analysis. Cluster I consisted of the sites S3, S8, S10 and S11 in the west and north coastal parts of Daya Bay. Cluster I is mainly related to anthropogenic activities such as fish-farming. Cluster II consisted of the rest of the stations in the center, east and south parts of Daya Bay. Cluster II is mainly related to seawater exchange from South China Sea. PMID:21776234

  2. Numerical simulation of hydrodynamic and water quality effects of shoreline changes in Bohai Bay

    Science.gov (United States)

    Jia, Han; Shen, Yongming; Su, Meirong; Yu, Chunxue

    2018-02-01

    This study uses the HD and Ecolab modules of MIKE to simulate the hydrodynamic and water quality and predict the influence of shoreline changes in Bohai Bay, China. The study shows that shoreline changes weaken the residual current and generate a counter-clockwise circulation south of Huanghua Port, thereby resulting in weak water exchange capacity and low pollutant-diffusing capacity. Shoreline changes reduce the area of Bohai Bay, resulting in a smaller tidal prism and further weakening the water exchange capacity. This situation is not conducive to the diffusion of pollutants, and therefore may lead to increased water pollution in the bay. Shoreline changes hinder the spread of runoff, weaken the dilution effect of the river on seawater, and block the spread of coastal residual current, thereby resulting in increased salinity near the reclamation area. Shoreline changes lead to an increase in PO4-P concentration and decrease in DIN concentration. The value of N/P near the project decreases, thereby weakening the phosphorus-limited effect.

  3. Water quality of the inner Puno Bay, Titicaca Lake, during summer 2011

    Directory of Open Access Journals (Sweden)

    Diana F. Beltrán Farfán

    2015-12-01

    Full Text Available Water quality of the inner Puno Bay was evaluated; we established 12 stations, and were assessed monthly from December 2010 to April 2011. Physicochemical water parameters were determined with EPA and APHA standard methods. Nutrients were determined spectrophotometrically. The parameters of temperature, dissolved oxygen, pH, phosphates, nitrates and nitrites of water show that the outlet of the stabilization lagoon of Puno City (Espinar Island is a critical area of contamination at the inner Puno Bay. Transparency values were low. The electrical conductivity of water showed high values. Alkalinity values were high (75 - 150 mg/L and very high (> 150 mg/L, indicating a high content of carbonates and bicarbonates. Water hardness were high (121-180 mg/L and very high (> 180 mg/L. High levels of fecal coliform in waters near the island Espinar would be the result of wastewater discharges from the Puno city, without proper treatment.

  4. 33 CFR 334.635 - Hillsborough Bay and waters contiguous to MacDill Air Force Base, Fla.; restricted area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Hillsborough Bay and waters... Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.635 Hillsborough Bay and waters contiguous to MacDill Air Force Base, Fla.; restricted area...

  5. Review and synthesis of historical Tampa Bay water quality data. Final technical report

    International Nuclear Information System (INIS)

    Vargo, G.; Weisberg, R.; Bendis, B.; Rutherford, E.H.

    1992-11-01

    The review and synthesis of historical water quality data was one of the first characterization projects administered by the Tampa Bay National Estuary Program (NEP). The objective of the project was to describe the physical, chemical and biological characteristics of Tampa Bay. The report examines the spatial and temporal trends from the acquired data for possible interrelationships and develops them statistically

  6. Pharmaceuticals in water, fish and osprey nestlings in Delaware River and Bay

    Science.gov (United States)

    Bean, Thomas G.; Rattner, Barnett A.; Lazarus, Rebecca S.; Day, Daniel D.; Burket, S. Rebekah; Brooks, Bryan W.; Haddad, Samuel P.; Bowerman, William W.

    2018-01-01

    Exposure of wildlife to Active Pharmaceutical Ingredients (APIs) is likely to occur but studies of risk are limited. One exposure pathway that has received attention is trophic transfer of APIs in a water-fish-osprey food chain. Samples of water, fish plasma and osprey plasma were collected from Delaware River and Bay, and analyzed for 21 APIs. Only 2 of 21 analytes exceeded method detection limits in osprey plasma (acetaminophen and diclofenac) with plasma levels typically 2–3 orders of magnitude below human therapeutic concentrations (HTC). We built upon a screening level model used to predict osprey exposure to APIs in Chesapeake Bay and evaluated whether exposure levels could have been predicted in Delaware Bay had we just measured concentrations in water or fish. Use of surface water and BCFs did not predict API concentrations in fish well, likely due to fish movement patterns, and partitioning and bioaccumulation uncertainties associated with these ionizable chemicals. Input of highest measured API concentration in fish plasma combined with pharmacokinetic data accurately predicted that diclofenac and acetaminophen would be the APIs most likely detected in osprey plasma. For the majority of APIs modeled, levels were not predicted to exceed 1 ng/mL or method detection limits in osprey plasma. Based on the target analytes examined, there is little evidence that APIs represent a significant risk to ospreys nesting in Delaware Bay. If an API is present in fish orders of magnitude below HTC, sampling of fish-eating birds is unlikely to be necessary. However, several human pharmaceuticals accumulated in fish plasma within a recommended safety factor for HTC. It is now important to expand the scope of diet-based API exposure modeling to include alternative exposure pathways (e.g., uptake from landfills, dumps and wastewater treatment plants) and geographic locations (developing countries) where API contamination of the environment may represent greater risk.

  7. Long time-series of turbid coastal water using AVHRR: an example from Florida Bay, USA

    Science.gov (United States)

    Stumpf, Richard P.; Frayer, M. L.

    1997-02-01

    The AVHRR can provide information on the reflectance of turbid case II water, permitting examination of large estuaries and plumes from major rivers. The AVHRR has been onboard several NOAA satellites, with afternoon overpasses since 1981, offering a long time-series to examine changes in coastal water. We are using AVHRR data starting in December 1989, to examine water clarity in Florida Bay, which has undergone a decline since the late 1980's. The processing involves obtaining a nominal reflectance for red light with standard corrections including those for Rayleigh and aerosol path radiances. Established relationships between reflectance and the water properties being measured in the Bay provide estimates of diffuse attenuation and light limitation for phytoplankton and seagrass productivity studies. Processing also includes monthly averages of reflectance and attenuation. The AVHRR data set describes spatial and temporal patterns, including resuspension of bottom sediments in the winter, and changes in water clarity. The AVHRR also indicates that Florida Bay has much higher reflectivity relative to attenuation than other southeastern US estuaries.

  8. Occurrence and distribution of antibiotics in coastal water of the Bohai Bay, China: Impacts of river discharge and aquaculture activities

    International Nuclear Information System (INIS)

    Zou Shichun; Xu Weihai; Zhang Ruijie; Tang Jianhui; Chen Yingjun; Zhang Gan

    2011-01-01

    The presence of 21 antibiotics in six different groups was investigated in coastal water of the Bohai Bay. Meantime, to illuminate the potential effects caused by the river discharge and aquaculture activities, wastewater from three breeding plants and surface water from six rivers flowing into the Bohai Bay were also analyzed for the selected antibiotics. The result revealed that measured antibiotics in the North Bobai Bay were generally higher than those in the South, highlighting the remarkable effects of high density of human activities on the exposure of antibiotics in environment. The antibiotics found in the six rivers were generally higher than those in the Bohai Bay reflecting the important antibiotics source of river discharge. This study reveals that the high consumption of some antibiotics in aquaculture activities may pose high ecological risk to the bay. - Highlights: → Some antibiotics were ubiquitous with high concentration in the Bohai bay, North China. → The antibiotics were mainly from the six rivers discharge around the Bay. → Antibiotics are commonly used in aquaculture activities around the Bay. → Aquaculture was suggested to be an important antibiotics source in the Bay. - River discharge and aquaculture were suggested to be important sources for antibiotics occurred in the coastal water of the Bohai Bay, North China.

  9. Shallow-water Benthic Habitat Map (2013) for Coral Bay, St. John

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This shapefile contains information about the shallow-water (<40 meters) geology and biology of the seafloor in Coral Bay, St. John in the U.S. Virgin Islands...

  10. Forewarning model for water pollution risk based on Bayes theory.

    Science.gov (United States)

    Zhao, Jun; Jin, Juliang; Guo, Qizhong; Chen, Yaqian; Lu, Mengxiong; Tinoco, Luis

    2014-02-01

    In order to reduce the losses by water pollution, forewarning model for water pollution risk based on Bayes theory was studied. This model is built upon risk indexes in complex systems, proceeding from the whole structure and its components. In this study, the principal components analysis is used to screen out index systems. Hydrological model is employed to simulate index value according to the prediction principle. Bayes theory is adopted to obtain posterior distribution by prior distribution with sample information which can make samples' features preferably reflect and represent the totals to some extent. Forewarning level is judged on the maximum probability rule, and then local conditions for proposing management strategies that will have the effect of transforming heavy warnings to a lesser degree. This study takes Taihu Basin as an example. After forewarning model application and vertification for water pollution risk from 2000 to 2009 between the actual and simulated data, forewarning level in 2010 is given as a severe warning, which is well coincide with logistic curve. It is shown that the model is rigorous in theory with flexible method, reasonable in result with simple structure, and it has strong logic superiority and regional adaptability, providing a new way for warning water pollution risk.

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

    Science.gov (United States)

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

    2015-09-01

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

  12. Waste water discharge and its effect on the quality of water of Mahim creek and bay

    Digital Repository Service at National Institute of Oceanography (India)

    Zingde, M.D.; Desai, B.N.

    Coastal environment around Mahim was monitored to evaluate the effects of domestic and industrial waste water discharge in Mahim Creek, Maharashtra, India. Vertical salinity and DO gradient occasionally observed in the Mahim Bay during postmonsoon...

  13. Metals content in surface waters of an upwelling system of the northern Humboldt Current (Mejillones Bay, Chile)

    Science.gov (United States)

    Valdés, Jorge; Román, Domingo; Alvarez, Gabriel; Ortlieb, Luc; Guiñez, Marcos

    Physical-chemical parameters (temperature, salinity, dissolved oxygen, nutrients, and chlorophyll concentration) of surface waters were used to evaluate the influence of biological and physical processes over the metal concentrations (Cd, Ni, V, Mo, Mn, and Fe) in different periods of a normal annual cycle (June 2002 and April 2003), in Mejillones Bay (23° S), one of northern Chile's strongest upwelling cells. Two points were sampled every 2 months, but statistical analysis of these parameters did not show any spatial differences in surface water composition (annual average) in this bay. The order of total and dissolved metals by abundance (annual mean) in the Mejillones Bay surface waters during the sampling period was Cd Oxygen Minimum Zone which characterizes the Mejillones bay should have an important influence on surface distribution of trace metals and can explain the high temporal variability observed in most of the metals analyzed in this work. A two-box conceptual model is proposed to suggest possible influences on metals in surface waters of this coastal ecosystem.

  14. 33 CFR 165.1182 - Safety/Security Zone: San Francisco Bay, San Pablo Bay, Carquinez Strait, and Suisun Bay, CA.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety/Security Zone: San... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY... Areas Eleventh Coast Guard District § 165.1182 Safety/Security Zone: San Francisco Bay, San Pablo Bay...

  15. A numerical model investigation of the impacts of Hurricane Sandy on water level variability in Great South Bay, New York

    Science.gov (United States)

    Bennett, Vanessa C. C.; Mulligan, Ryan P.; Hapke, Cheryl J.

    2018-06-01

    Hurricane Sandy was a large and intense storm with high winds that caused total water levels from combined tides and storm surge to reach 4.0 m in the Atlantic Ocean and 2.5 m in Great South Bay (GSB), a back-barrier bay between Fire Island and Long Island, New York. In this study the impact of the hurricane winds and waves are examined in order to understand the flow of ocean water into the back-barrier bay and water level variations within the bay. To accomplish this goal, a high resolution hurricane wind field is used to drive the coupled Delft3D-SWAN hydrodynamic and wave models over a series of grids with the finest resolution in GSB. The processes that control water levels in the back-barrier bay are investigated by comparing the results of four cases that include: (i) tides only; (ii) tides, winds and waves with no overwash over Fire Island allowed; (iii) tides, winds, waves and limited overwash at the east end of the island; (iv) tides, winds, waves and extensive overwash along the island. The results indicate that strong local wind-driven storm surge along the bay axis had the largest influence on the total water level fluctuations during the hurricane. However, the simulations allowing for overwash have higher correlation with water level observations in GSB and suggest that island overwash provided a significant contribution of ocean water to eastern GSB during the storm. The computations indicate that overwash of 7500-10,000 m3s-1 was approximately the same as the inflow from the ocean through the major existing inlet. Overall, the model results indicate the complex variability in total water levels driven by tides, ocean storm surge, surge from local winds, and overwash that had a significant impact on the circulation in Great South Bay during Hurricane Sandy.

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

    Science.gov (United States)

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

    2012-01-01

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

  17. Are the Chesapeake Bay waters warming up

    International Nuclear Information System (INIS)

    Brady, D.K.

    1976-01-01

    Apparently significant trends within moderately long (50-year) series of meteorological or hydrological data should be regarded with suspicion until justified on the basis of much longer term information. Extra efforts should be directed toward securing the continuance of routine observations at stations where long data histories are already available and where the termination of such records might be regretted at some future time. Mean annual air and water temperatures at different sites may be quite highly correlated even when the points of measurement are very widely separated. The annual average water temperature at one station close to the Chesapeake Bay appears to be normally distributed with a standard deviation of 0.7 0 C about a stationary overall mean value of 14.6 0 C. Its 1000-year departure is +- 2.2 0 C

  18. Changes in Stream Water Temperatures in the Chesapeake Bay Region, 1960-2014

    Science.gov (United States)

    This map shows the changes in stream water temperatures in the Chesapeake Bay region from 1960 to 2014. Blue circles represent cooling trends in stream water temperatures, and red circles represent warming trends in stream water temperatures. Data were analyzed by Mike Kolian of EPA in partnership with John Jastram and Karen Rice of the U.S. Geological Survey. For more information: www.epa.gov/climatechange/science/indicators

  19. Molecular Approach to Microbiological Examination of Water Quality in the Grand Bay National Estuarine Research Reserve (NERR) in Mississippi, USA.

    Science.gov (United States)

    Kishinhi, Stephen S; Tchounwou, Paul B; Farah, Ibrahim O

    2013-01-01

    Grand Bay National Estuarine Research Reserve (NERR) is an important ecosystem in the Mississippi Gulf Coast. It serves as important nursery areas for juveniles of many species of fish. The bay is also used for fishing, crabbing, oyster togging, boating as well as recreation. Like in other aquatic environments, this bay may be contaminated by microorganisms including pathogenic bacteria. The objective of this study was to evaluate the microbiological quality of water in the Grand Bay NERR and determine the levels and potential source(s) of human fecal pollution. To achieve this goal, water samples were collected aseptically every month in Bayou Heron, Bayou Cumbest, Point Aux Chenes Bay and Bangs Lake. Enterococci were concentrated from water samples by membrane filtration according to the methodology outlined in USEPA Method 1600. After incubation, DNA was extracted from bacteria colonies on the membrane filters by using QIAamp DNA extraction kit. Water samples were also tested for the presence of traditional indicator bacteria including: heterotrophic plate count, total coliforms, fecal coliforms, and Enterococcus bacteria. The marker esp gene was detected in one site of Bayou Cumbest, an area where human populations reside. Data from this study indicates higher concentrations of indicator bacteria compared to the recommended acceptable levels. Presence of esp marker and high numbers of indicator bacteria suggest a public health concern for shellfish and water contact activities. Hence, control strategies should be developed and implemented to prevent further contamination of the Grand bay NERR waters.

  20. Future trends in urbanization and coastal water pollution in the Bay of Bengal: the lived experience

    NARCIS (Netherlands)

    Zinia, N.J.; Kroeze, C.

    2015-01-01

    The Bay of Bengal includes coastal seas of several countries, including Bangladesh, India, and Myanmar. We present scenarios for future river export of eutrophying nutrients into the Bay of Bengal, and the role of urbanization therein. We used NEWS (Nutrient Export from WaterSheds) model to analyze

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

    Science.gov (United States)

    Huang, Xiao-Lan; Zhang, Jia-Zhong

    2010-10-15

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

  2. Discharge between San Antonio Bay and Aransas Bay, southern Gulf Coast, Texas, May-September 1999

    Science.gov (United States)

    East, Jeffery W.

    2001-01-01

    Along the Gulf Coast of Texas, many estuaries and bays are important habitat and nurseries for aquatic life. San Antonio Bay and Aransas Bay, located about 50 and 30 miles northeast, respectively, of Corpus Christi, are two important estuarine nurseries on the southern Gulf Coast of Texas (fig. 1). According to the Texas Parks and Wildlife Department, “Almost 80 percent of the seagrasses [along the Texas Gulf Coast] are located in the Laguna Madre, an estuary that begins just south of Corpus Christi Bay and runs southward 140 miles to South Padre Island. Most of the remaining seagrasses, about 45,000 acres, are located in the heavily traveled San Antonio, Aransas and Corpus Christi Bay areas” (Shook, 2000).Population growth has led to greater demands on water supplies in Texas. The Texas Water Development Board, the Texas Parks and Wildlife Department, and the Texas Natural Resource Conservation Commission have the cooperative task of determining inflows required to maintain the ecological health of the State’s streams, rivers, bays, and estuaries. To determine these inflow requirements, the three agencies collect data and conduct studies on the need for instream flows and freshwater/ saline water inflows to Texas estuaries.To assist in the determination of freshwater inflow requirements, the U.S. Geological Survey (USGS), in cooperation with the Texas Water Development Board, conducted a hydrographic survey of discharge (flow) between San Antonio Bay and Aransas Bay during the period May–September 1999. Automated instrumentation and acoustic technology were used to maximize the amount and quality of data that were collected, while minimizing personnel requirements. This report documents the discharge measured at two sites between the bays during May–September 1999 and describes the influences of meteorologic (wind and tidal) and hydrologic (freshwater inflow) conditions on discharge between the two bays. The movement of water between the bays is

  3. A numerical model investigation of the impacts of Hurricane Sandy on water level variability in Great South Bay, New York

    Science.gov (United States)

    Bennett, Vanessa C. C.; Mulligan, Ryan P.; Hapke, Cheryl J.

    2018-01-01

    Hurricane Sandy was a large and intense storm with high winds that caused total water levels from combined tides and storm surge to reach 4.0 m in the Atlantic Ocean and 2.5 m in Great South Bay (GSB), a back-barrier bay between Fire Island and Long Island, New York. In this study the impact of the hurricane winds and waves are examined in order to understand the flow of ocean water into the back-barrier bay and water level variations within the bay. To accomplish this goal, a high resolution hurricane wind field is used to drive the coupled Delft3D-SWAN hydrodynamic and wave models over a series of grids with the finest resolution in GSB. The processes that control water levels in the back-barrier bay are investigated by comparing the results of four cases that include: (i) tides only; (ii) tides, winds and waves with no overwash over Fire Island allowed; (iii) tides, winds, waves and limited overwash at the east end of the island; (iv) tides, winds, waves and extensive overwash along the island. The results indicate that strong local wind-driven storm surge along the bay axis had the largest influence on the total water level fluctuations during the hurricane. However, the simulations allowing for overwash have higher correlation with water level observations in GSB and suggest that island overwash provided a significant contribution of ocean water to eastern GSB during the storm. The computations indicate that overwash of 7500–10,000 m3s−1 was approximately the same as the inflow from the ocean through the major existing inlet. Overall, the model results indicate the complex variability in total water levels driven by tides, ocean storm surge, surge from local winds, and overwash that had a significant impact on the circulation in Great South Bay during Hurricane Sandy.

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

    International Nuclear Information System (INIS)

    Zhou, J.L.; Maskaoui, K.

    2003-01-01

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

  5. Preventing Pollution to Local Waters, Bay; Preserving Historic Natural Bridge in Virginia

    Science.gov (United States)

    In helping to preserve one of the oldest tourist destinations in the country – a spectacular natural land bridge in Virginia – EPA funding is protecting the surrounding land from development that would have impacted local waters and the Chesapeake Bay.

  6. Bio-optical water quality dynamics observed from MERIS in Pensacola Bay, Florida

    Science.gov (United States)

    Observed bio-optical water quality data collected from 2009 to 2011 in Pensacola Bay, Florida were used to develop empirical remote sensing retrieval algorithms for chlorophyll a (Chla), colored dissolved organic matter (CDOM), and suspended particulate matter (SPM). Time-series ...

  7. Degradation of tributyltin in San Diego Bay, California, waters

    International Nuclear Information System (INIS)

    Seligman, P.F.; Valkirs, A.O.; Lee, R.F.

    1986-01-01

    Several experiments were carried out to determine the degradation rate of tributyltin (TBT) in microcosms containing harbor water. Unlabeled or 14 C-labeled tributyltin was added to water samples collected from two stations in San Diego Bay, CA. Degradation rates were determined by calculating the rate of loss of the added parent TBT compound. Calculated half-lives in water collected from a yacht harbor (ambient concentration was 0.5 μg of TBT/L) were 6 and 7 days for light and dark treatments, respectively. Half-lives from a clean-water site ( 14 CO 2 , proceeded slowly with a half-life of 50-75 days. Tributyltin at high concentrations (744 μg/L) was not degraded in sunlight, indicating that photolysis was not taking place and that biological degradation was the primary degradative process for TBT at low ambient concentrations

  8. Time series monitoring of water quality and microalgal diversity in a tropical bay under intense anthropogenic interference (SW coast of the Bay of Bengal, India)

    Energy Technology Data Exchange (ETDEWEB)

    Shaik, Aziz ur Rahman [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India); Biswas, Haimanti, E-mail: haimanti.biswas@nio.org [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India); Reddy, N.P.C.; Srinivasa Rao, V. [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India); Bharathi, M.D. [Present address: ICMAM Project Directorate, 2nd Floor, NIOT Campus, Velacherry-Tambaram Main Road, Pallikkaranai, Chennai 600100 (India); Subbaiah, Ch.V. [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India)

    2015-11-15

    In recent decades, material fluxes to coastal waters from various land based anthropogenic activities have significantly been enhanced around the globe which can considerably impact the coastal water quality and ecosystem health. Hence, there is a critical need to understand the links between anthropogenic activities in watersheds and its health. Kakinada Bay is situated at the SW part of the Bay of Bengal, near to the second largest mangrove cover in India with several fertilizer industries along its bank and could be highly vulnerable to different types of pollutants. However, virtually, no data is available so far reporting its physicochemical status and microalgal diversity at this bay. In order to fill this gap, we conducted three time series observations at a fixed station during January, December and June 2012, at this bay measuring more than 15 physical, chemical and biological parameters in every 3 h over a period of 36 h in both surface (0 m) and subsurface (4.5 m) waters. Our results clearly depict a strong seasonality between three sampling months; however, any abnormal values of nutrients, biological oxygen demand or dissolved oxygen level was not observed. A Skeletonema costatum bloom was observed in December which was probably influenced by low saline, high turbid and high Si input through the river discharge. Otherwise, smaller diatoms like Thalassiosira decipiens, Thalassiothrix frauenfeldii, and Thalassionema nitzschioides dominated the bay. It is likely that the material loading can be high at the point sources due to intense anthropogenic activities, however, gets diluted with biological, chemical and physical processes in the offshore waters. - Highlights: • No signature of enormous nutrient loading was observed over the diel cycle • Dissolved oxygen and BOD concentrations did not show any exceptional trend • Diatoms dominated more than 90% of the total phytoplankton communities • A Skeletonema Costatum (a centric diatom) bloom was

  9. Time series monitoring of water quality and microalgal diversity in a tropical bay under intense anthropogenic interference (SW coast of the Bay of Bengal, India)

    International Nuclear Information System (INIS)

    Shaik, Aziz ur Rahman; Biswas, Haimanti; Reddy, N.P.C.; Srinivasa Rao, V.; Bharathi, M.D.; Subbaiah, Ch.V.

    2015-01-01

    In recent decades, material fluxes to coastal waters from various land based anthropogenic activities have significantly been enhanced around the globe which can considerably impact the coastal water quality and ecosystem health. Hence, there is a critical need to understand the links between anthropogenic activities in watersheds and its health. Kakinada Bay is situated at the SW part of the Bay of Bengal, near to the second largest mangrove cover in India with several fertilizer industries along its bank and could be highly vulnerable to different types of pollutants. However, virtually, no data is available so far reporting its physicochemical status and microalgal diversity at this bay. In order to fill this gap, we conducted three time series observations at a fixed station during January, December and June 2012, at this bay measuring more than 15 physical, chemical and biological parameters in every 3 h over a period of 36 h in both surface (0 m) and subsurface (4.5 m) waters. Our results clearly depict a strong seasonality between three sampling months; however, any abnormal values of nutrients, biological oxygen demand or dissolved oxygen level was not observed. A Skeletonema costatum bloom was observed in December which was probably influenced by low saline, high turbid and high Si input through the river discharge. Otherwise, smaller diatoms like Thalassiosira decipiens, Thalassiothrix frauenfeldii, and Thalassionema nitzschioides dominated the bay. It is likely that the material loading can be high at the point sources due to intense anthropogenic activities, however, gets diluted with biological, chemical and physical processes in the offshore waters. - Highlights: • No signature of enormous nutrient loading was observed over the diel cycle • Dissolved oxygen and BOD concentrations did not show any exceptional trend • Diatoms dominated more than 90% of the total phytoplankton communities • A Skeletonema Costatum (a centric diatom) bloom was

  10. California State Waters Map Series: offshore of Half Moon Bay, California

    Science.gov (United States)

    Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Johnson, Samuel Y.; Golden, Nadine E.; Hartwell, Stephen R.; Dieter, Bryan E.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Watt, Janet T.; Endris, Charles A.; Kvitek, Rikk G.; Phillips, Eleyne L.; Erdey, Mercedes D.; Chin, John L.; Bretz, Carrie K.

    2014-01-01

    In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. The Offshore of Half Moon Bay map area is located in northern California, on the Pacific coast of the San Francisco Peninsula about 40 kilometers south of the Golden Gate. The city of Half Moon Bay, which is situated on the east side of the Half Moon Bay embayment, is the nearest significant onshore cultural center in the map area, with a population of about 11,000. The Pillar Point Harbor at the north edge of Half Moon Bay offers a protected landing for boats and provides other marine infrastructure. The map area lies offshore of the Santa Cruz Mountains, part of the northwest-trending Coast Ranges that run roughly parallel to the San Andreas Fault Zone. The Santa Cruz Mountains lie between the San Andreas Fault Zone and the San Gregorio Fault system. The flat coastal area, which is the most recent of numerous marine terraces, was formed by wave erosion about 105 thousand years ago. The higher elevation of this same terrace west of the Half Moon Bay Airport is caused by uplift on the Seal Cove Fault, a splay of the San Gregorio Fault Zone. Although originally incised into the rising terrain horizontally, the ancient terrace surface has been gently folded into a northwest-plunging syncline by

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  12. Studies on Anthropogenic Impact on Water Quality in Hilo (Hawaii) Bay and Mapping the Study Stations Using Geospatial Technologies

    Science.gov (United States)

    Cartier, A. J.; Williams, M. S.; Adolf, J.; Sriharan, S.

    2015-12-01

    Hilo Bay has uncharacteristically brown waters compared to other waters found in Hawai'i. The majority of the freshwater entering Hilo Bay is from storm and surface water runoff. The anthropogenic impact on water quality at Hilo Bay is due to sediment entrance, cesspools (Bacteria), and invasive species (Albizia). This poster presentation will focus on the water quality and phytoplankton collected on a weekly basis at a buoy positioned one meter from the shore of Hilo Bay, preserving the phytoplankton intact, concentrating and dehydrating the sample with ethanol, and viewing the phytoplankton with a scanning electron microscope (Hitachi S-3400NII). The GPS (Global Positioning System) points were collected at the sampling stations. Three transects on three separate dates were performed in Hilo Bay with salinity, percent dissolved oxygen, turbidity, secchi depth, temperature, and chlorophyll fluorescence data collected at each sampling station. A consistent trend observed in all transects was as distance from the river increased turbidity decreased and salinity increased. The GPS data on June 30, 2015 showed a major correlation between stations and their distance from shore. There is a decrease in the turbidity but not the temperature for these stations. The GPS points collected on July 7, 2015 at thirteen stations starting with station one being at the shore to the water, showed that the salinity concentration fluctuate noticeably at the first 6 stations. As we proceed further away from the shore, the salinity concentration increases from stations seven through thirteen. The water temperature shows little variation throughout the thirteen stations. The turbidity level was high at the shore and shows a noticeable drop at station thirteen.

  13. Radionuclides in sediments from Port Phillip Bay, Australia

    International Nuclear Information System (INIS)

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

    1998-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Abiodun O. Adeniji

    2017-10-01

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

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

    Science.gov (United States)

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

    2017-10-20

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-19

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

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

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

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

  19. Occurrence and distribution of antibiotics in coastal water of the Bohai Bay, China: impacts of river discharge and aquaculture activities.

    Science.gov (United States)

    Zou, Shichun; Xu, Weihai; Zhang, Ruijie; Tang, Jianhui; Chen, Yingjun; Zhang, Gan

    2011-10-01

    The presence of 21 antibiotics in six different groups was investigated in coastal water of the Bohai Bay. Meantime, to illuminate the potential effects caused by the river discharge and aquaculture activities, wastewater from three breeding plants and surface water from six rivers flowing into the Bohai Bay were also analyzed for the selected antibiotics. The result revealed that measured antibiotics in the North Bobai Bay were generally higher than those in the South, highlighting the remarkable effects of high density of human activities on the exposure of antibiotics in environment. The antibiotics found in the six rivers were generally higher than those in the Bohai Bay reflecting the important antibiotics source of river discharge. This study reveals that the high consumption of some antibiotics in aquaculture activities may pose high ecological risk to the bay. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Long-term trends in submersed aquatic vegetation (SAV) in Chesapeake Bay, USA, related to water quality

    Science.gov (United States)

    Orth, Robert J.; Williams, Michael R.; Marion, Scott R.; Wilcox, David J.; Carruthers, Tim J.B.; Moore, Kenneth A.; Kemp, W.M.; Dennison, William C.; Rybicki, Nancy B.; Peter Bergstrom,; Batiuk, Richard A.

    2010-01-01

    Chesapeake Bay supports a diverse assemblage of marine and freshwater species of submersed aquatic vegetation (SAV) whose broad distributions are generally constrained by salinity. An annual aerial SAV monitoring program and a bi-monthly to monthly water quality monitoring program have been conducted throughout Chesapeake Bay since 1984. We performed an analysis of SAV abundance and up to 22 environmental variables potentially influencing SAV growth and abundance (1984-2006). Historically, SAV abundance has changed dramatically in Chesapeake Bay, and since 1984, when SAV abundance was at historic low levels, SAV has exhibited complex changes including long-term (decadal) increases and decreases, as well as some large, single-year changes. Chesapeake Bay SAV was grouped into three broad-scale community-types based on salinity regime, each with their own distinct group of species, and detailed analyses were conducted on these three community-types as well as on seven distinct case-study areas spanning the three salinity regimes. Different trends in SAVabundance were evident in the different salinity regimes. SAV abundance has (a) continually increased in the low-salinity region; (b) increased initially in the medium-salinity region, followed by fluctuating abundances; and (c) increased initially in the high-salinity region, followed by a subsequent decline. In all areas, consistent negative correlations between measures of SAV abundance and nitrogen loads or concentrations suggest that meadows are responsive to changes in inputs of nitrogen. For smaller case-study areas, different trends in SAV abundance were also noted including correlations to water clarity in high-salinity case-study areas, but nitrogen was highly correlated in all areas. Current maximum SAV coverage for almost all areas remain below restoration targets, indicating that SAV abundance and associated ecosystem services are currently limited by continued poor water quality, and specifically high

  1. Stable hydrogen and oxygen isotopes of tap water reveal structure of the San Francisco Bay Area's water system and adjustments during a major drought.

    Science.gov (United States)

    Tipple, Brett J; Jameel, Yusuf; Chau, Thuan H; Mancuso, Christy J; Bowen, Gabriel J; Dufour, Alexis; Chesson, Lesley A; Ehleringer, James R

    2017-08-01

    Water availability and sustainability in the Western United States is a major flashpoint among expanding communities, growing industries, and productive agricultural lands. This issue came to a head in 2015 in the State of California, when the State mandated a 25% reduction in urban water use following a multi-year drought that significantly depleted water resources. Water demands and challenges in supplying water are only expected to intensify as climate perturbations, such as the 2012-2015 California Drought, become more common. As a consequence, there is an increased need to understand linkages between urban centers, water transport and usage, and the impacts of climate change on water resources. To assess if stable hydrogen and oxygen isotope ratios could increase the understanding of these relationships within a megalopolis in the Western United States, we collected and analyzed 723 tap waters across the San Francisco Bay Area during seven collection campaigns spanning 21 months during 2013-2015. The San Francisco Bay Area was selected as it has well-characterized water management strategies and the 2012-2105 California Drought dramatically affected its water resources. Consistent with known water management strategies and previously collected isotope data, we found large spatiotemporal variations in the δ 2 H and δ 18 O values of tap waters within the Bay Area. This is indicative of complex water transport systems and varying municipality-scale management decisions. We observed δ 2 H and δ 18 O values of tap water consistent with waters originating from snowmelt from the Sierra Nevada Mountains, local precipitation, ground water, and partially evaporated reservoir sources. A cluster analysis of the isotope data collected in this study grouped waters from 43 static sampling sites that were associated with specific water utility providers within the San Francisco Bay Area and known management practices. Various management responses to the drought, such as

  2. Urban Greening Bay Area

    Science.gov (United States)

    Information about the San Francisco Bay Water Quality Project (SFBWQP) Urban Greening Bay Area, a large-scale effort to re-envision urban landscapes to include green infrastructure (GI) making communities more livable and reducing stormwater runoff.

  3. San Francisco Bay Water Quality Improvement Fund Map Service, San Francisco CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  4. San Francisco Bay Water Quality Improvement Fund Project Locations, San Francisco CA, 2017, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  5. Spatial and seasonal patterns of ichthyoplankton assemblages in the Haizhou Bay and its adjacent waters of China

    Science.gov (United States)

    Li, Zengguang; Ye, Zhenjiang; Wan, Rong

    2015-12-01

    Surveys were conducted in five voyages in Haizhou Bay and its adjacent coastal area from March to December 2011 during full moon spring tides. The ichthyoplankton assemblages and the environmental factors that affect their spatial and seasonal patterns were determined. Totally 35 and 12 fish egg and larvae taxa were identified, respectively. Over the past several decades, the egg and larval species composition has significantly changed in Haizhou Bay and its adjacent waters, most likely corresponding with the alteration of fishery resources, which are strongly affected by anthropogenic activities and climate change. The Bray-Curtis dissimilarity index identified four assemblages: near-shore bay assemblage, middle bay assemblage and two closely related assemblages (near-shore/middle bay assemblage and middle/edge of bay assemblage). The primary species of each assemblage principally reflected the spawning strategies of adult fish. The near-shore bay assemblage generally occurred in near-shore bay, with depths measuring ichthyoplankton in each assemblage were determined by interactions between biological behavioral traits and oceanographic features, particularly the variation of local conditions within the constraint of a general reproductive strategy. The results of Spearman's rank correlation analysis indicated that both fish egg and larval abundance were positively correlated with depth, which is critical to the oceanographic features in Haizhou Bay.

  6. Escherichia coli in the surface waters and in oysters of two cultivations of Guaratuba Bay - Paraná - Brazil

    OpenAIRE

    Forcelini,Helenita Catharina Dalla-Lana; Kolm,Hedda Elisabeth; Absher,Theresinha Monteiro

    2013-01-01

    The present work aimed to evaluate the contamination of Escherichia coli in the surface waters and oysters from two cultivations of Guaratuba Bay and to analyze the correlation patterns among the concentrations of E. coli in the waters and in the oysters with the local physical-chemical parameters. Samples were collected in the spring of 2007 and summer, autumn and winter of 2008 from two points of the bay (internal point and external point). From each cultivation and sampling period, 18 oyst...

  7. 78 FR 62293 - Safety Zone, Oyster Festival 30th Anniversary Fireworks Display, Oyster Bay; Oyster Bay, NY

    Science.gov (United States)

    2013-10-15

    ... Safety Zone, Oyster Festival 30th Anniversary Fireworks Display, Oyster Bay; Oyster Bay, NY AGENCY: Coast... zone on the navigable waters of Oyster Bay near Oyster Bay, NY for the Oyster Festival 30th Anniversary... Oyster Festival 30th Anniversary Fireworks Display is scheduled for October 19, 2013 and is one of...

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

    Science.gov (United States)

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

    2016-05-01

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

  9. South Bay Salt Pond Mercury Studies Project

    Science.gov (United States)

    Information about the SFBWQP South Bay Salt Pond Mercury Studies Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  10. 78 FR 39608 - Safety Zone; Summer in the City Water Ski Show; Fox River, Green Bay, WI

    Science.gov (United States)

    2013-07-02

    ...-AA00 Safety Zone; Summer in the City Water Ski Show; Fox River, Green Bay, WI AGENCY: Coast Guard, DHS... River in Green Bay, WI. This safety zone is intended to restrict vessels from a portion of the Fox River... Waterboard Warrior Ski Team will perform two 30-minute shows on the Fox River between the Hwy 141 Bridge and...

  11. The impact of water loading on postglacial decay times in Hudson Bay

    Science.gov (United States)

    Han, Holly Kyeore; Gomez, Natalya

    2018-05-01

    Ongoing glacial isostatic adjustment (GIA) due to surface loading (ice and water) variations during the last glacial cycle has been contributing to sea-level changes globally throughout the Holocene, especially in regions like Canada that were heavily glaciated during the Last Glacial Maximum (LGM). The spatial and temporal distribution of GIA, as manifested in relative sea-level (RSL) change, are sensitive to the ice history and the rheological structure of the solid Earth, both of which are uncertain. It has been shown that RSL curves near the center of previously glaciated regions with no ongoing surface loading follow an exponential-like form, with the postglacial decay times associated with that form having a weak sensitivity to the details of the ice loading history. Postglacial decay time estimates thus provide a powerful datum for constraining the Earth's viscous structure and improving GIA predictions. We explore spatial patterns of postglacial decay time predictions in Hudson Bay by decomposing numerically modeled RSL changes into contributions from water and ice loading effects, and computing their relative impact on the decay times. We demonstrate that ice loading can contribute a strong geographic trend on the decay time estimates if the time window used to compute decay times includes periods that are temporally close to (i.e. contemporaneous with, or soon after) periods of active loading. This variability can be avoided by choosing a suitable starting point for the decay time window. However, more surprisingly, we show that across any adopted time window, water loading effects associated with inundation into, and postglacial flux out of, Hudson Bay and James Bay will impart significant geographic variability onto decay time estimates. We emphasize this issue by considering both maps of predicted decay times across the region and site-specific estimates, and we conclude that variability in observed decay times (whether based on existing or future data

  12. Microbial processes in the Kanda Bay, a meromictic water body artifically separated from the White Sea.

    Science.gov (United States)

    Savvichev, A S; Demidenko, N A; Krasnova, E D; Kalmatskaya, O V; Kharcheva, A N; Ivanov, M V

    2017-05-01

    Sings of meromixis are found by means of microbiological and biogeochemical investigations in the southernn part of the Kanda Bay, an artificial water body separated front the White Sea with a railway dam. The concentration of oxygen in the bottom layer attained 1.9 mmol/L, intensity of the process of microbial sulfate reduction, 3.0 μmol of sulfur/(L day). The concentration of dissolved methane, 3.7 μmol/L. Isotopic composition of carbon in methane (δ 13 C (CH 4 ) =-79.2‰) indicates to its microbial genesis. At present, Kanda Bay is a sole in Russia man-made marine water body for which there are data on the rate of microbial processes responsible for formation of bottom water layer containing hydrogen sulfide and methane.

  13. Physical and chemical properties of San Francisco Bay waters, 1969-1976 (NODC Accession 8400194)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — One magnetic tape containing the physical and chemical properties of San Francisco Bay waters was forwarded to NODC by Mr. Richard Smith of the U.S Geological Survey...

  14. Experimental study of water desorption isotherms and thin-layer convective drying kinetics of bay laurel leaves

    Science.gov (United States)

    Ghnimi, Thouraya; Hassini, Lamine; Bagane, Mohamed

    2016-12-01

    The aim of this work is to determine the desorption isotherms and the drying kinetics of bay laurel leaves ( Laurus Nobilis L.). The desorption isotherms were performed at three temperature levels: 50, 60 and 70 °C and at water activity ranging from 0.057 to 0.88 using the statistic gravimetric method. Five sorption models were used to fit desorption experimental isotherm data. It was found that Kuhn model offers the best fitting of experimental moisture isotherms in the mentioned investigated ranges of temperature and water activity. The Net isosteric heat of water desorption was evaluated using The Clausius-Clapeyron equation and was then best correlated to equilibrium moisture content by the empirical Tsami's equation. Thin layer convective drying curves of bay laurel leaves were obtained for temperatures of 45, 50, 60 and 70 °C, relative humidity of 5, 15, 30 and 45 % and air velocities of 1, 1.5 and 2 m/s. A non linear regression procedure of Levenberg-Marquardt was used to fit drying curves with five semi empirical mathematical models available in the literature, The R2 and χ2 were used to evaluate the goodness of fit of models to data. Based on the experimental drying curves the drying characteristic curve (DCC) has been established and fitted with a third degree polynomial function. It was found that the Midilli Kucuk model was the best semi-empirical model describing thin layer drying kinetics of bay laurel leaves. The bay laurel leaves effective moisture diffusivity and activation energy were also identified.

  15. Robust Decision Making to Support Water Quality Climate Adaptation: a Case Study in the Chesapeake Bay Watershed

    Science.gov (United States)

    Fischbach, J. R.; Lempert, R. J.; Molina-Perez, E.

    2017-12-01

    The U.S. Environmental Protection Agency (USEPA), together with state and local partners, develops watershed implementation plans designed to meet water quality standards. Climate uncertainty, along with uncertainty about future land use changes or the performance of water quality best management practices (BMPs), may make it difficult for these implementation plans to meet water quality goals. In this effort, we explored how decision making under deep uncertainty (DMDU) methods such as Robust Decision Making (RDM) could help USEPA and its partners develop implementation plans that are more robust to future uncertainty. The study focuses on one part of the Chesapeake Bay watershed, the Patuxent River, which is 2,479 sq km in area, highly urbanized, and has a rapidly growing population. We simulated the contribution of stormwater contaminants from the Patuxent to the overall Total Maximum Daily Load (TMDL) for the Chesapeake Bay under multiple scenarios reflecting climate and other uncertainties. Contaminants considered included nitrogen, phosphorus, and sediment loads. The assessment included a large set of scenario simulations using the USEPA Chesapeake Bay Program's Phase V watershed model. Uncertainties represented in the analysis included 18 downscaled climate projections (based on 6 general circulation models and 3 emissions pathways), 12 land use scenarios with different population projections and development patterns, and alternative assumptions about BMP performance standards and efficiencies associated with different suites of stormwater BMPs. Finally, we developed cost estimates for each of the performance standards and compared cost to TMDL performance as a key tradeoff for future water quality management decisions. In this talk, we describe how this research can help inform climate-related decision support at USEPA's Chesapeake Bay Program, and more generally how RDM and other DMDU methods can support improved water quality management under climate

  16. Biological effect on removal of Th-234, Po-210 and Pb-210 from surface water in Funka Bay, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, N; Takeda, Y; Tsunogai, S [Hokkaido Univ., Hakodate (Japan). Dept. of Chemistry

    1983-10-01

    Vertical and temporal variations in the radioactivities of Th-234, Pb-210 and Po-210 were measured at a station in Funka Bay from April 1979 to February 1980. The inventory of Th-234 showed a minimum in early spring, when a spring bloom of phytoplankton was observed, then a steady increase to a maximum value in late summer, just before open sea water invaded the bay and a secondary phytoplankton bloom started. The inventories of Pb-210 and Po-210 also showed minima in early spring. These results suggest that the removal of these nuclides from sea water is accelerated by biological activity. The concentration of Th-234 decreased with depth, but those of Po-210 and Pb-210 were higher in the bottom water in August 1979 when the bay water was strongly stratified. This may be due to the supply of Pb-210 and Po-210 from the bottom. However, if the supply of these nuclides is expected in sediment particles, the concentrations of these nuclides in suspended matter were not sufficient to explain their increments in the bottom water. Residence times of Th, Pb and Po were estimated.

  17. Distribution characteristics of radium isotopes and their influence factors in the water of Jiaozhou Bay area

    International Nuclear Information System (INIS)

    Wang Bo; Guo Zhanrong; Yuan Xiaojie; Zhang Bin; Ma Zhiyong; Liu Jie

    2014-01-01

    Background: The interaction between continental and oceanic process is much intense in coastal region. The terrestrial freshwater mixes with seawater here which leads to the chemical constituents in water undergo rapid change. Purpose: The aim is to analyze and study the distribution characteristics of 224 Ra and 226 Ra and their influence factors in the water of Jiaozhou Bay area. Methods: The water samples of 224 Ra and 226 Ra were collected from groundwater, river water and seawater around the Jiaozhou Bay from April to May, 2012. In the laboratory, the activities of 224 Ra absorbed on the Mn-fiber were measured through the continuous emanation method. Finally, the Mn-fiber was sealed for more than 7 days, and the activities of 226 Ra absorbed on the Mn-fiber were measured through the direct emanation method. Results: The results show that the activities of 224 Ra and 226 Ra in groundwater and river water are much higher in the granitic area which has higher concentration of 232 Th and 238 U. Because of mixing with seawater, the salinity of groundwater and river water in coastal region rises which leads to the increasing amounts of 224 Ra and 226 Ra desorbed from the particles, resulting in higher activities of 224 Ra and 226 Ra in coastal region. Affected by the input of river (dissolved and desorbed from suspended particles) and submarine groundwater discharge (SGD), the activities of 224 Ra and 226 Ra are relatively higher in nearshore seawater, then with the decay of 224 Ra and mixing dilution effect of the offshore seawater, the activities of 224 Ra gradually decrease from nearshore region to the open ocean. The activities of 226 Ra in the seawater of Jiaozhou Bay remain high-level values, and there are only a few zones of low 226 Ra activities. The main reasons are that the activities of 226 Ra from terrestrial freshwater are close to those from offshore seawater and the half-life of 226 Ra is very long. Conclusion: The activities of 224 Ra and 226 Ra in

  18. Isotope geochemistry of waters affected by mining activities in Sierra Minera and Portman Bay (SE, Spain)

    International Nuclear Information System (INIS)

    García-Lorenzo, Mari Luz; Martínez-Sánchez, María José; Pérez-Sirvent, Carmen; Agudo, Inés; Recio, Clemente

    2014-01-01

    Highlights: • Waters have a meteoric origin even in samples located near the shore. • Marine infiltration only takes place in the deepest layers. • Sulfate enrichment was caused by oxidative dissolution of pyrite by ferric iron. - Abstract: The objective of this work was to evaluate processes affecting waters from Portman Bay by way of stable isotopic analysis, particularly H and O stable isotopes from water and S and O from dissolved sulfates. In addition, surface waters from Sierra Minera were examined for the purpose of determining if these waters are affected by similar processes. The results obtained indicate that Portman Bay waters are meteoric, and marine infiltration only takes place in the deepest layers near the shore or if water remains stagnated in sediments with low permeability. The main source of sulfate was the oxidation of sulfides, resulting in the liberation of acid, sulfate and metals. In order to assess the mechanism responsible for sulfide oxidation, the stoichiometric isotope balance model and the general isotope balance model were tested, suggesting that the oxidation via Fe 3+ was predominant in the surface, and controlled by Acidithiobacillus ferrooxidans, while at depth, sulfate reduction occurred

  19. WATER QUALITY AND ITS EFFECT ON GROWTH AND SURVIVAL RATE OF LOBSTER REARED IN FLOATING NET CAGE IN EKAS BAY, WEST NUSA TENGGARA PROVINCE

    Directory of Open Access Journals (Sweden)

    Muhammad Junaidi

    2015-02-01

    Full Text Available ABSTRACT The development of lobster farming in floating net cage in Ekas Bay caused an environmental degradation such as decrease water quality due to some aquaculture wastes. The purposes of this study were to determine the status of water quality and their effect on growth and survival rate of lobster reared in floating net cages (FNC in the Ekas Bay, West Nusa Tenggara Province. Water sample collection and handling referred to the APHA (1992. Analyses of water quality data were conducted using Principal Component Analysis. Determination of the water quality status of Ekas Bay was performed with STORET system. Multivariate analyses were used to determine the relationship between water quality, growth, and survival rate of lobster reared in FNC. Results showed that Ekas Bay water quality status was categorized in class C (medium contaminated, which exceeded some quality standard parameters such as ammonia (0.3 mg/l, nitrate (0.008 mg/l, and phosphate (0.015 mg/l. During lobster farming activities feeding with trash fish for 270 days, we obtained daily growth rate of  0.74% (lower than normal growth rate of 0.86%, survival rate of 66% (lower than normal survival rate of 86.7%, and feed conversion ratio of 11.15. Ammonia was found as a dominant factor reducing growth  and survival rate of lobster reared in FNC. Keywords: water quality, lobsters, growth, survival, Ekas Bay

  20. Bacterial biomass and heterotrophic potential in the waters of the Chesapeake Bay plume and contiguous continental shelf

    Science.gov (United States)

    Kator, H. I.; Zubkoff, P. L.

    1981-01-01

    Seasonal baseline data on bacterial biomass and heterotrophic uptake in the Chesapeake Bay plume and contiguous Atlantic Ocean shelf waters are discussed. Viable count bacterial numbers in surface water samples collected during June 1980 ranged from a maximum of 190,000 MPN (most probable number)/ml at the Bay mouth to a minimum of 7900 MPN/ml offshore. Similarly, direct count densities ranged from 1,800,000 BU (bacterial units)/ml to 24,000 BU/ml. Heterotrophic potential (V max) was largest at the Bay mouth and lowest offshore. Biomass and V max values usually decreased with depth although subsurface maxima were occasionally observed at inshore stations. Correlation of biomass and heterotrophic potential data with selected hydrographic variables was determind with a nonparametric statistic. Results indicate viable counts are positively and significantly correlated with total chlorophyll, temperature, direct count and V max during June 1980; significant negative correlations are obtained with salinity and depth. Calculations of bacterial standing crop are discussed.

  1. On watermass mixing ratios and regenerated silicon in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.P.; Sarma, V.V.; Rao, V.S.; Sudhakar, U.; Gupta, G.V.M.

    Regeneration of silicon on mixing in the Bay of Bengal have been computed from six water masses [Bay of Bengal low saline water (BBLS), Bay of Bengal subsurface water (BBSS), northern southeast high salinity water (NSEHS), north Indian intermediate...

  2. The contingent behavior of charter fishing participants on the Chesapeake Bay: Welfare estimates associated with water quality improvements

    Science.gov (United States)

    Poor, P.J.; Breece, M.

    2006-01-01

    Water quality in the Chesapeake Bay has deteriorated over recent years. Historically, fishing has contributed to the region's local economy in terms of commercial and recreational harvests. A contingent behavior model is used to estimate welfare measures for charter fishing participants with regard to a hypothetical improvement in water quality. Using a truncated Poisson count model corrected for endogenous stratification, it was found that charter fishers not only contribute to the local market economy, but they also place positive non-market value on preserving the Bay's water quality. Using two estimates for travels costs it is estimated that the individual consumer surplus is $200 and $117 per trip, and the average individual consumer surplus values for an improvement in water quality is $75 and $44 for two models estimated. ?? 2006 University of Newcastle upon Tyne.

  3. 78 FR 79312 - Security Zone; On the Waters in Kailua Bay, Oahu, HI

    Science.gov (United States)

    2013-12-30

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket Number USCG-2013-0934] RIN 1625-AA87 Security Zone; On the Waters in Kailua Bay, Oahu, HI AGENCY: Coast Guard, DHS. ACTION..., Oahu, HI. (a) Location. The following area, within the COTP Honolulu Zone (see 33 CFR 3.70-10), from...

  4. The numbers of ringed seals (Phoca hispida in Baffin Bay and associated waters

    Directory of Open Access Journals (Sweden)

    Michael C S Kingsley

    1998-06-01

    Full Text Available The size of the population of ringed seals (Phoca hispida inhabiting Baffin Bay and associated waters was estimated by two methods. An approximate model of the energetics of the polar bear (Ursus maritimus estimated an energetic need of about 16,000 MJ/bear per year. Modelled estimates of the energetic yield of a ringed seal population showed that a stable standing population of 140-170 ringed seals per bear would be needed to provide that much energy, assuming that all mortalities were due to polar bear predation. This result was sensitive to assumptions about the Field Metabolic Rate (FMR of the bears and the energetic yield of individual ringed seals, but less sensitive to assumptions about relative incidence of predation on different age classes of seal or the age structure of the polar bear population. Estimated sizes of polar bear populations in Baffin Bay and associated waters (total about 4,025, and of the standing population needed to support an estimated hunter kill of 100,000 yielded a population estimate of, very roughly, 1.2 million ringed seals. Estimates of ice areas and of the density of hauled out seals from aerial surveys were used to generate another approximate figure for the ringed seal population, which was about the same. The density of seals in the pack-ice area of Baffin Bay, which is imperfectly known, has a large influence on the latter estimate.

  5. Development, calibration, and analysis of a hydrologic and water-quality model of the Delaware Inland Bays watershed

    Science.gov (United States)

    Gutierrez-Magness, Angelica L.; Raffensperger, Jeff P.

    2003-01-01

    Excessive nutrients and sediment are among the most significant environmental stressors in the Delaware Inland Bays (Rehoboth, Indian River, and Little Assawoman Bays). Sources of nutrients, sediment, and other contaminants within the Inland Bays watershed include point-source discharges from industries and wastewater-treatment plants, runoff and infiltration to ground water from agricultural fields and poultry operations, effluent from on-site wastewater disposal systems, and atmospheric deposition. To determine the most effective restoration methods for the Inland Bays, it is necessary to understand the relative distribution and contribution of each of the possible sources of nutrients, sediment, and other contaminants. A cooperative study involving the Delaware Department of Natural Resources and Environmental Control, the Delaware Geological Survey, and the U.S. Geological Survey was initiated in 2000 to develop a hydrologic and water-quality model of the Delaware Inland Bays watershed that can be used as a water-resources planning and management tool. The model code Hydrological Simulation Program - FORTRAN (HSPF) was used. The 719-square-kilometer watershed was divided into 45 model segments, and the model was calibrated using streamflow and water-quality data for January 1999 through April 2000 from six U.S. Geological Survey stream-gaging stations within the watershed. Calibration for some parameters was accomplished using PEST, a model-independent parameter estimator. Model parameters were adjusted systematically so that the discrepancies between the simulated values and the corresponding observations were minimized. Modeling results indicate that soil and aquifer permeability, ditching, dominant land-use class, and land-use practices affect the amount of runoff, the mechanism or flow path (surface flow, interflow, or base flow), and the loads of sediment and nutrients. In general, the edge-of-stream total suspended solids yields in the Inland Bays

  6. 76 FR 12 - Security Zone; On the Waters in Kailua Bay, Oahu, HI

    Science.gov (United States)

    2011-01-03

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2010-1111] RIN 1625-AA87 Security Zone; On the Waters in Kailua Bay, Oahu, HI AGENCY: Coast Guard, DHS. ACTION: Temporary..., Oahu, HI. (a) Location. The following area, within the Honolulu Captain of the Port Zone (See 33 CFR 3...

  7. 76 FR 80251 - Security Zone; On the Waters in Kailua Bay, Oahu, HI

    Science.gov (United States)

    2011-12-23

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2011-1142] RIN 1625-AA87 Security Zone; On the Waters in Kailua Bay, Oahu, HI AGENCY: Coast Guard, DHS. ACTION: Temporary..., HI. (a) Location. The following area, within the Honolulu Captain of the Port Zone (See 33 CFR 3.70...

  8. Fecal indicator bacteria at Havana Bay

    International Nuclear Information System (INIS)

    Lopez Perez, Lisse; Gomez D'Angelo, Yamiris; Beltran Gonzalez, Jesus; Alvarez Valiente, Reinaldo

    2013-01-01

    Aims: Fecal indicator bacteria concentrations were evaluated in Havana Bay. Methods: Concentrations of traditional fecal indicator bacteria were calculated between April 2010 and February 2011, by MPN methods. Concentrations of thermo tolerant coliform (CTT), Escherichia coli, fecal streptococci (EF), intestinal enterococci (ENT) in seawater, and Clostridium perfringens in sediment surface, were determined. Results: CTT and E. coli levels were far above Cuban water quality standard for indirect contact with water, showing the negative influence of sewage and rivers on the bay. The EF and ENT were measured during sewage spills at the discharge site and they were suitable indicators of fecal contamination, but these indicators didn't show the same behavior in other selected sites. This result comes from its well-known inactivation by solar light in tropical zones and the presumable presence of humid acids in the waters of the bay. Conclusion: Fecal indicator bacteria and its statistical relationships reflect recent and chronic fecal contamination at the bay and near shores.

  9. A New Small Drifter for Shallow Water Basins: Application to the Study of Surface Currents in the Muggia Bay (Italy

    Directory of Open Access Journals (Sweden)

    Carmelo Nasello

    2016-01-01

    Full Text Available A new small drifter prototype for measuring current immediately below the free surface in a water basin is proposed in this paper. The drifter dimensions make it useful for shallow water applications. The drifter transmits its GPS location via GSM phone network. The drifter was used to study the trajectory of the surface current in the Muggia bay, the latter containing the industrial harbor of the city of Trieste (Italy. The analysis has been carried out under a wide variety of wind conditions. As regards the behavior of the drifter, the analysis has shown that it is well suited to detect the water current since its motion is marginally affected by the wind. The study has allowed detecting the main features of the surface circulation within the Muggia bay under different meteorological conditions. Also, the study has shown that the trajectory of the surface current within the bay is weakly affected by the Coriolis force.

  10. Present status of grouper fisheries at waters of Kotania Bay, Western Seram District Maluku Province

    Science.gov (United States)

    Huliselan, N. V.; Wawo, M.; Tuapattinaja, M. A.; Sahetapy, D.

    2017-10-01

    Study on present status of groupers fishes at waters of Kotania Bay was conducted from 2016 to 2017. Survey and Participatory Rural Appraisal (PRA) method were used to collect and examine data and information concerning species potential and utilization of these species. The result shows that there are 35 species of grouper fishes inhabit Kotania Bay waters. From six genera recorded, Epinephelus found to have more varieties species richness compared to other five genera. In general, main habitat of adult grouper is coral reef, whilst mangrove and seagrass are habitat for nursery and grow out. The potency of the Epinephelus, Cephalopholis and Plectropomus genus tend to decrease started in 2000 up to 2017. At the same period, the production of these genera was also declined. Species potency and production declined was attributable to habitat (coral reef) degradation and high fishing intensity as a result of high market demand. Hand line, bottom long line and trap net are general fishing gear used in harvesting of theses fishes. Fishing activities took place all year round except for bottom long line which only lasted from June to October (East monsoon). Spatial fishing ground distribution is predominantly at coral reef ecosystem of Kotania Bay.

  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. Trends in Surface-Water Nitrate-N Concentrations and Loads from Predominantly-Forested Watersheds of the Chesapeake Bay Basin

    Science.gov (United States)

    Eshleman, K. N.

    2011-12-01

    Water quality monitoring data from streams and rivers provide the "gold standard" by which progress toward achieving real reductions in nutrient loadings to Chesapeake Bay must ultimately be assessed. The most recent trend results posted at the Chesapeake Bay Program (CBP) website reveal that a substantial percentage of tributaries are now showing long-term declines in flow-adjusted concentrations of nutrients and sediments: 22 sites showed statistically significant (p pollution controls for improved wastewater treatment plants and practices to reduce nutrients on farms and suburban lands, have reduced concentrations of nitrogen." But could this conclusion be pre-mature? I recently undertook a comparable analysis of long-term nitrate-N trends for a different group of watersheds (all located in the Chesapeake Bay watershed with long data records); this group includes nine watersheds that are predominantly (i.e., >75%) forested, plus five other Potomac River subwatersheds added for comparison. Based on comparable data and analytical methods to those used by CBP partners and USGS, 13 of the 14 sites-including both Potomac River stations (Chain Bridge at Washington DC and Hancock, Maryland)-showed statistically significant decreasing linear trends in annual flow-weighted nitrate-N concentration. Only one station-the heavily agricultural Upper Monocacy River-did not show a statistically significant (p RIM station could be entirely explained by commensurate improvements at the upstream (Hancock) station; in fact, no trend in nitrate-N concentration associated with the eastern portion of the basin was found (after subtracting out the influence of the upstream portion). Additional research is needed to understand why nitrogen retention by forested lands may be increasing and thus helping restore water quality throughout the Chesapeake Bay watershed. The results also have obvious implications for meeting local water quality goals as well as the basin-wide goal of the

  13. Distribution characteristics of volatile methylsiloxanes in Tokyo Bay watershed in Japan: Analysis of surface waters by purge and trap method.

    Science.gov (United States)

    Horii, Yuichi; Minomo, Kotaro; Ohtsuka, Nobutoshi; Motegi, Mamoru; Nojiri, Kiyoshi; Kannan, Kurunthachalam

    2017-05-15

    Surface waters including river water and effluent from sewage treatment plants (STPs) were collected from Tokyo Bay watershed, Japan, and analyzed for seven cyclic and linear volatile methylsiloxanes (VMSs), i.e., D3, D4, D5, D6, L3, L4, and L5 by an optimized purge and trap extraction method. The total concentrations of seven VMSs (ΣVMS) in river water ranged from watershed was estimated at 2300kg. Our results indicate widespread distribution of VMSs in Tokyo Bay watershed and the influence of domestic wastewater discharges as a source of VMSs in the aquatic environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Salinity maxima associated with some sub-surface water masses in the upper layers of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Varadachari, V.V.R.; Murty, C.S.; Reddy, C.V.G.

    The distribution of some sub-surface water masses in the western bay of Bengal during the south-west monsoon period is presented. Based on the salinity maxima and sigma t values the existence of waters of Persian Gulf and Red Sea origin could...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-08-01

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

  16. Spectral Wave Characteristics in the Nearshore Waters of Northwestern Bay of Bengal

    Science.gov (United States)

    Anjali Nair, M.; Sanil Kumar, V.; Amrutha, M. M.

    2018-03-01

    The spectral wave characteristics in the nearshore waters of northwestern Bay of Bengal are presented based on the buoy-measured data from February 2013 to December 2015 off Gopalpur at 15-m water depth. The mean seasonal significant wave height and mean wave period indicate that the occurrence of higher wave heights and wave periods is during the southwest monsoon period (June-September). 74% of the sea surface height variance in a year is a result of waves from 138 to 228° and 16% are from 48 to 138°. Strong inter-annual variability is observed in the monthly average wave parameters due to the occurrence of tropical cyclones. Due to the influence of the tropical cyclone Phailin, maximum significant wave height of 6.7 m is observed on 12 October 2013 and that due to tropical cyclone Hudhud whose track is 250 southwest of the study location is 5.84 m on 12 October 2014. Analysis revealed that a single tropical cyclone influenced the annual maximum significant wave height and not the annual average value which is almost same ( 1 m) in 2014 and 2015. The waves in the northwestern Bay of Bengal are influenced by the southwest and northeast monsoons, southern ocean swells and cyclones.

  17. Hydrochemistry of the Bay of Bengal: Possible reasons for a different water-column cycling of carbon and nitrogen from the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, C.K.; Naqvi, S.W.A.; DileepKumar, M.; Varaprasad, S.J.D.; Jayakumar, D.A.; George, M.D.; Singbal, S.Y.S.

    of the Arabian Sea, firmly indicating that the Bay of Bengal is not an active denitrification site. The absence of denitrification in the Bay appears to be incompatible with a slower renewal of intermediate waters and a higher sinking flux of particulate organic...

  18. Effect of water temperature on survival of early-life stages of marbled flounder Pseudopleuronectes yokohamae in Tokyo Bay, Japan.

    Science.gov (United States)

    Lee, Jeong-Hoon; Kodama, Keita; Oyama, Masaaki; Shiraishi, Hiroaki; Horiguchi, Toshihiro

    2017-07-01

    We investigated factors that might have disturbed the stock recovery of marbled flounder in Tokyo Bay by focusing on the early life stages. Field surveys in Tokyo Bay from 2006 to 2011 revealed that mature adult biomass increased from 2006 to 2008 and decreased thereafter. Meanwhile, larval and juvenile densities were high in 2006 and 2008 but low in other years. Discrepancies in the yearly trends of these parameters suggest that mortality during life stages between spawning and early larval phases might have affected the abundance of the subsequent life stages. Monthly mean water temperature between January and February, in which hatching and pelagic larvae occur in the bay, was lower in 2006 (8.6 °C) and 2008 (9.6 °C) than was observed in other years (10.4-11.4 °C). Significant negative correlation between water temperature and larval density implies that mortality during pre- and post-larval stages would be higher in warmer winter years (>10 °C). To test this hypothesis, we examined the effects of water temperature on mortality and development in egg and larval stages under controlled laboratory conditions. Hatching rate was high in a water temperature range of 9.2-12.7 °C (66.6-82.5%), whereas it decreased in cooler (3.7% at 5.9 °C) or warmer (33.9% at 14.8 °C) conditions. Meanwhile, days from fertilization to hatching, size of larvae at hatching and survival rate of larvae after 18 d from hatching were monotonically and significantly decreased as water temperature was elevated. Combined evidence of the field and laboratory studies suggests that a warmer reproductive season (>10 °C) might induce mortalities of marbled flounder larvae in Tokyo Bay. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Influence of strong monsoon winds on the water quality around a marine cage-culture zone in a shallow and semi-enclosed bay in Taiwan.

    Science.gov (United States)

    Huang, Yuan-Chao Angelo; Huang, Shou-Chung; Meng, Pei-Jie; Hsieh, Hernyi Justin; Chen, Chaolun Allen

    2012-04-01

    Influences of marine cage culture and monsoonal disturbances, northeasterly (NE) and southwesterly (SW) monsoons on the proximal marine environment were investigated across a gradient of sites in a semi-enclosed bay, Magong Bay (Penghu Islands, Taiwan). Elevated levels of ammonia produced by the cages were the main pollutant and distinguished the cage-culture and intermediary zones (1000 m away from the cages) from the reference zone in the NE monsoon, indicating currents produced by the strong monsoon may have extended the spread of nutrient-enriched waters without necessarily flushing such effluents outside Magong Bay. Moreover, the levels of chlorophyll-a, dissolved oxygen, and turbidity were distinguishable between two seasons, suggesting that resuspension caused by the NE monsoon winds may also influence the water quality across this bay. It indicated that the impacts of marine cage culture vary as a function of distance, and also in response to seasonal movements of water driven by local climatic occurrences. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Chesapeake Bay plume dynamics from LANDSAT

    Science.gov (United States)

    Munday, J. C., Jr.; Fedosh, M. S.

    1981-01-01

    LANDSAT images with enhancement and density slicing show that the Chesapeake Bay plume usually frequents the Virginia coast south of the Bay mouth. Southwestern (compared to northern) winds spread the plume easterly over a large area. Ebb tide images (compared to flood tide images) show a more dispersed plume. Flooding waters produce high turbidity levels over the shallow northern portion of the Bay mouth.

  1. South Bay Salt Pond Restoration, Phase II at Ravenswood

    Science.gov (United States)

    Information about the South Bay Salt Pond Restoration Project: Phase II Construction at Ravenswood, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  2. Social-Ecological System in Seagrass Ecosystem Management at Kotania Bay Waters, Western Seram, Indonesia

    Science.gov (United States)

    Wawo, Mintje

    2017-10-01

    The concept of the Social-Ecological System (SES) of the coastal region, can be found in the seagrass ecosystem in the Kotania Bay Waters. Seagrass ecosystem as one of the productive ecosystem is part of an ecological system that can influence and influenced social system, in this case by people living around the seagrass ecosystem. This aim to estimating the socio-ecological vulnerability system of the seagrass ecosystem in the Kotania Bay Waters, the Linkage Matrix is used (de Chazal et al., 2008). This linkage matrix was created to determine the perception and understanding of the community on the ecosystem services provided by the seagrass ecosystem through the appraisal of various stakeholders. The results show that social values are rooted in the public perception of ecosystem goods and services, which are rarely considered. The ecological and economic value of natural resources is increasingly being used to determine the priority areas in the planning and management of coastal areas. The social value that exists in natural resources is highly recognized in conservation.

  3. 226Ra and 228Ra in the mixing zones of the Pee Dee River-Winyah Bay, Yangtze River and Delaware Bay Estuaries

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  4. Impact of the large-scale Arctic circulation and the North Water Polynya on nutrient inventories in Baffin Bay

    Science.gov (United States)

    Tremblay, Jean-Éric; Gratton, Yves; Carmack, Eddy C.; Payne, Christopher D.; Price, Neil M.

    2002-08-01

    The distributions of nitrate, phosphate, and silicate in northern Baffin Bay were determined from 90 bottle casts taken between April 11 and July 21, 1998. During late spring, low-salinity Arctic water entered northern Smith Sound and mixed with Baffin Bay water (BBW) within the North Water Polynya. The Arctic water originated from the Bering Sea and contained high concentrations of phosphate and silicate (referred to as silicate-rich Arctic water (SRAW)). The distribution of the two water masses was established using a new tracer, Siex, which showed moderate penetration of SRAW into Smith Sound during April and a very strong incursion in May and June, consistent with the intensification of southward current velocities. Biological depletion of macronutrients in BBW began in April and continued until nitrate was exhausted from the upper mixed layer in early June. Beneath the Polynya the deep waters (>450 m) showed a marked increase in nutrient concentration toward the bottom, which was most pronounced in the south and much stronger for silicate than nitrate and phosphate. The silicate enrichment was consistent with dissolution of diatom-derived biogenic silica in deep waters. The results indicate that the North Water acts as a silicate trap in which the biota differentially transports surface silicate to depth, thereby influencing local and downstream nutrient signatures.

  5. 33 CFR 80.1430 - Kaneohe Bay, Oahu, HI.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kaneohe Bay, Oahu, HI. 80.1430 Section 80.1430 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Islands § 80.1430 Kaneohe Bay, Oahu, HI. A straight line...

  6. 33 CFR 80.1420 - Mamala Bay, Oahu, HI.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Mamala Bay, Oahu, HI. 80.1420 Section 80.1420 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Islands § 80.1420 Mamala Bay, Oahu, HI. A line drawn from...

  7. Integrating science and resource management in Tampa Bay, Florida

    Science.gov (United States)

    Yates, Kimberly K.; Greening, Holly; Morrison, Gerold

    2011-01-01

    Tampa Bay is recognized internationally for its remarkable progress towards recovery since it was pronounced "dead" in the late 1970s. Due to significant efforts by local governments, industries and private citizens throughout the watershed, water clarity in Tampa Bay is now equal to what it was in 1950, when population in the watershed was less than one-quarter of what it is today. Seagrass extent has increased by more than 8,000 acres since the mid-1980s, and fish and wildlife populations are increasing. Central to this successful turn-around has been the Tampa Bay resource management community's long-term commitment to development and implementation of strong science-based management strategies. Research institutions and agencies, including Eckerd College, the Florida Wildlife Commission Fish and Wildlife Research Institute, Mote Marine Laboratory, National Oceanic and Atmospheric Administration, the Southwest Florida Water Management District, University of South Florida, U.S. Environmental Protection Agency, U.S. Geological Survey, local and State governments, and private companies contribute significantly to the scientific basis of our understanding of Tampa Bay's structure and ecological function. Resource management agencies, including the Tampa Bay Regional Planning Council's Agency on Bay Management, the Southwest Florida Water Management District's Surface Water Improvement and Management Program, and the Tampa Bay Estuary Program, depend upon this scientific basis to develop and implement regional adaptive management programs. The importance of integrating science with management has become fully recognized by scientists and managers throughout the region, State and Nation. Scientific studies conducted in Tampa Bay over the past 10–15 years are increasingly diverse and complex, and resource management programs reflect our increased knowledge of geology, hydrology and hydrodynamics, ecology and restoration techniques. However, a synthesis of this

  8. Relationship of land use to water quality in the Chesapeake Bay region. [water sampling and photomapping river basins

    Science.gov (United States)

    Correll, D. L.

    1978-01-01

    Both the proportions of the various land use categories present on each watershed and the specific management practices in use in each category affect the quality of runoff waters, and the water quality of the Bay. Several permanent and portable stations on various Maryland Rivers collect volume-integrated water samples. All samples are analyzed for a series of nutrient, particulate, bacterial, herbicide, and heavy metal parameters. Each basin is mapped with respect to land use by the analysis of low-elevation aerial photos. Analyses are verified and adjusted by ground truth surveys. Data are processed and stored in the Smithsonian Institution data bank. Land use categories being investigated include forests/old fields, pastureland, row crops, residential areas, upland swamps, and tidal marshes.

  9. Evaluation of coastal waters receiving fish processing waste: Lota Bay as a case study.

    Science.gov (United States)

    Ahumada, Ramón; Rudolph, Anny; Contreras, Sergio

    2004-01-01

    Liquid wastes from the fish meal and oil processing industries produce serious environmental impacts in coastal embayments on the coasts of Chile and Peru. This article presents an analysis of an environmental monitoring program at Lota Bay, a shallow coastal indentation in central Chile (37 degrees S) exposed to industrial fishing activity. The study of the environmental impact produced by waste effluents permitted making an evaluation of the bay's capacity for seasonal recovery from this impact. Seasonal cruises were carried out during 1994 and in 1996, 1997, and 1998. Variables analyzed included salinity, temperature, dissolved oxygen, ammonium concentration and surface oil and grease. The hydrographic regime of Lota Bay follows a seasonal pattern, where, typical of most SE pacific embayments, waters from subsuperficial oxygen minimum zones moved into the bay. The percentages of dissolved oxygen were critical in the area of organic waste discharge. The impact of wastewater is related to the type and status of the fishery, including: (i) overloads of plant production lines, (ii) maintenance and cleaning of installations, and (iii) degree of shipboard fishing conservation. Major alterations were observed in summer, when the highest discharge of organic load occurred. In winter, an improvement in the re-aeration conditions reduced the impact. Remedial measures implemented beginning in 1997 arose from the monitoring program and had to be separated into two recovery factors including (a) internal management of plants and (b) treatment of plant effluents.

  10. Mobile Bay turbidity plume study

    Science.gov (United States)

    Crozier, G. F.

    1976-01-01

    Laboratory and field transmissometer studies on the effect of suspended particulate material upon the appearance of water are reported. Quantitative correlations were developed between remotely sensed image density, optical sea truth data, and actual sediment load. Evaluation of satellite image sea truth data for an offshore plume projects contours of transmissivity for two different tidal phases. Data clearly demonstrate the speed of change and movement of the optical plume for water patterns associated with the mouth of Mobile bay in which relatively clear Gulf of Mexico water enters the bay on the eastern side. Data show that wind stress in excess of 15 knots has a marked impact in producing suspended sediment loads.

  11. South Bay Salt Pond Tidal Wetland Restoration Phase II Planning

    Science.gov (United States)

    Information about the SFBWQP South Bay Salt Pond Tidal Wetland Restoration Phase II Planning project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic re

  12. DEVELOP Chesapeake Bay Watershed Hydrology - UAV Sensor Web

    Science.gov (United States)

    Holley, S. D.; Baruah, A.

    2008-12-01

    The Chesapeake Bay is the largest estuary in the United States, with a watershed extending through six states and the nation's capital. Urbanization and agriculture practices have led to an excess runoff of nutrients and sediment into the bay. Nutrients and sediment loading stimulate the growth of algal blooms associated with various problems including localized dissolved oxygen deficiencies, toxic algal blooms and death of marine life. The Chesapeake Bay Program, among other stakeholder organizations, contributes greatly to the restoration efforts of the Chesapeake Bay. These stakeholders contribute in many ways such as monitoring the water quality, leading clean-up projects, and actively restoring native habitats. The first stage of the DEVELOP Chesapeake Bay Coastal Management project, relating to water quality, contributed to the restoration efforts by introducing NASA satellite-based water quality data products to the stakeholders as a complement to their current monitoring methods. The second stage, to be initiated in the fall 2008 internship term, will focus on the impacts of land cover variability within the Chesapeake Bay Watershed. Multiple student led discussions with members of the Land Cover team at the Chesapeake Bay Program Office in the DEVELOP GSFC 2008 summer term uncovered the need for remote sensing data for hydrological mapping in the watershed. The Chesapeake Bay Program expressed in repeated discussions on Land Cover mapping that significant portions of upper river areas, streams, and the land directly interfacing those waters are not accurately depicted in the watershed model. Without such hydrological mapping correlated with land cover data the model will not be useful in depicting source areas of nutrient loading which has an ecological and economic impact in and around the Chesapeake Bay. The fall 2008 DEVELOP team will examine the use of UAV flown sensors in connection with in-situ and Earth Observation satellite data. To maximize the

  13. Evaluation of effects of changes in canal management and precipitation patterns on salinity in Biscayne Bay, Florida, using an integrated surface-water/groundwater model

    Science.gov (United States)

    Lohmann, Melinda A.; Swain, Eric D.; Wang, John D.; Dixon, Joann

    2012-01-01

    Biscayne National Park, located in Biscayne Bay in southeast Florida, is one of the largest marine parks in the country and sustains a large natural marine fishery where numerous threatened and endangered species reproduce. In recent years, the bay has experienced hypersaline conditions (salinity greater than 35 practical salinity units) of increasing magnitude and duration. Hypersalinity events were particularly pronounced during April to August 2004 in nearshore areas along the southern and middle parts of the bay. Prolonged hypersaline conditions can cause degradation of water quality and permanent damage to, or loss of, brackish nursery habitats for multiple species of fish and crustaceans as well as damage to certain types of seagrasses that are not tolerant of extreme changes in salinity. To evaluate the factors that contribute to hypersalinity events and to test the effects of possible changes in precipitation patterns and canal flows into Biscayne Bay on salinity in the bay, the U.S. Geological Survey constructed a coupled surface-water/groundwater numerical flow model. The model is designed to account for freshwater flows into Biscayne Bay through the canal system, leakage of salty bay water into the underlying Biscayne aquifer, discharge of fresh and salty groundwater from the Biscayne aquifer into the bay, direct effects of precipitation on bay salinity, indirect effects of precipitation on recharge to the Biscayne aquifer, direct effects of evapotranspiration (ET) on bay salinity, indirect effects of ET on recharge to the Biscayne aquifer, and maintenance of mass balance of both water and solute. The model was constructed using the Flow and Transport in a Linked Overland/Aquifer Density Dependent System (FTLOADDS) simulator, version 3.3, which couples the two-dimensional, surface-water flow and solute-transport simulator SWIFT2D with the density-dependent, groundwater flow an solute-transport simulator SEAWAT. The model was calibrated by a trial

  14. Derivation of Delaware Bay tidal parameters from space shuttle photography

    International Nuclear Information System (INIS)

    Zheng, Quanan; Yan, Xiaohai; Klemas, V.

    1993-01-01

    The tide-related parameters of the Delaware Bay are derived from space shuttle time-series photographs. The water areas in the bay are measured from interpretation maps of the photographs with a CALCOMP 9100 digitizer and ERDAS Image Processing System. The corresponding tidal levels are calculated using the exposure time annotated on the photographs. From these data, an approximate function relating the water area to the tidal level at a reference point is determined. Based on the function, the water areas of the Delaware Bay at mean high water (MHW) and mean low water (MLW), below 0 m, and for the tidal zone are inferred. With MHW and MLW areas and the mean tidal range, the authors calculate the tidal influx of the Delaware Bay, which is 2.76 x 1O 9 m 3 . Furthermore, the velocity of flood tide at the bay mouth is determined using the tidal flux and an integral of the velocity distribution function at the cross section between Cape Henlopen and Cape May. The result is 132 cm/s, which compares well with the data on tidal current charts

  15. Chemistry of Hot Spring Pool Waters in Calamba and Los Banos and Potential Effect on the Water Quality of Laguna De Bay

    Science.gov (United States)

    Balangue, M. I. R. D.; Pena, M. A. Z.; Siringan, F. P.; Jago-on, K. A. B.; Lloren, R. B.; Taniguchi, M.

    2014-12-01

    Since the Spanish Period (1600s), natural hot spring waters have been harnessed for balneological purposes in the municipalities of Calamba and Los Banos, Laguna, south of Metro Manila. There are at more than a hundred hot spring resorts in Brgy. Pansol, Calamba and Tadlac, Los Banos. These two areas are found at the northern flanks of Mt. Makiling facing Laguna de Bay. This study aims to provide some insights on the physical and chemical characteristics of hot spring resorts and the possible impact on the lake water quality resulting from the disposal of used water. Initial ocular survey of the resorts showed that temperature of the pool water ranges from ambient (>300C) to as high as 500C with an average pool size of 80m3. Water samples were collected from a natural hot spring and pumped well in Los Banos and another pumped well in Pansol to determine the chemistry. The field pH ranges from 6.65 to 6.87 (Pansol springs). Cation analysis revealed that the thermal waters belonged to the Na-K-Cl-HCO3 type with some trace amount of heavy metals. Methods for waste water disposal are either by direct discharge down the drain of the pool or by discharge in the public road canal. Both methods will dump the waste water directly into Laguna de Bay. Taking in consideration the large volume of waste water used especially during the peak season, the effect on the lake water quality would be significant. It is therefore imperative for the environmental authorities in Laguna to regulate and monitor the chemistry of discharges from the pool to protect both the lake water as well as groundwater quality.

  16. Assessment of a Mega-Float on water quality and ecosystem in Tokyo bay; Choogata futaishiki kaiyo kozobutsu ga Tokyowan no suishitsu to seitaikei ni oyobosu eikyo ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Kyozuka, Y.; Hu, C.; Hasemi, H. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Hikai, A.

    1997-08-01

    The effect on the marine environment in the bay when a Mega-Float is installed in a bay was investigated. The physical process such as a residual flow (including tidal currents, water temperature, salt, density, and density currents), and the ecosystem model for which floating organic matter and plankton are handled were incorporated to develop a program for water quality calculation in a bay. The program was used for Tokyo Bay and compared with the conventional calculation result and the oceanograhpic observation result. Simultaneously, the effect on the Mega-Float was considered. On the flow in Tokyo Bay in summer, the calculation result that comparatively coincided with the observation value in a residual flow level was obtained. The horizontal distribution of COD comparatively coincides with the existing observation result. The influence that the Mega-Float exerts on the flow, water temperature, water quality, and ecosystem in the ambient sea area was little and local in the calculation scale (L {times} B {times} d = 6 km {times} 3 km {times} 2 m) of this time. However, the difference occurring due to the design position must also be investigated in future. 12 refs., 8 figs., 5 tabs.

  17. Magnitude and Distribution of Flows into Northeastern Florida Bay

    Science.gov (United States)

    Patino, Eduardo; Hittle, Clinton D.

    2000-01-01

    Changes in water-management practices have been made to accommodate a large and rapidly growing urban population along the Atlantic Coast and to meet the demand for intensive agricultural activities. These changes have resulted in a highly managed hydrologic system consisting of numerous canals, levees, control structures, and pumping stations that have altered the hydrology of the Everglades and Florida Bay ecosystems. Over the past decade, Florida Bay has experienced sea-grass die-off and algal blooms, which are indicators of ecological change attributed primarily to the increase in salinity and nutrient content of bay waters. Because plans are to restore sheetflow in the Everglades wetlands to its natural state, water managers anticipate a change in the magnitude and timing of freshwater exiting the mainland through the creeks that cut through the embankment or as sheetflow into Florida Bay.

  18. Evolution of extreme high waters along the east coast of India and at the head of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, C.; Unnikrishnan, A.S.; Woodworth, P.L.

    . The highest water levels above mean sea level have the greatest magnitude towards the northern part of the Bay, which decreases towards its south-west. Extreme high waters were observed to result from a combination of moderate, or even small, surges with large...

  19. Changing Salinity Patterns in Biscayne Bay, Florida

    Science.gov (United States)

    ,

    2004-01-01

    Biscayne Bay, Fla., is a 428-square-mile (1,109-square-kilometer) subtropical estuarine ecosystem that includes Biscayne National Park, the largest marine park in the U.S. national park system (fig. 1). The bay began forming between 5,000 and 3,000 years ago as sea level rose and southern Florida was flooded. Throughout most of its history, the pristine waters of the bay supported abundant and diverse fauna and flora, and the bay was a nursery for the adjacent coral-reef and marine ecosystems. In the 20th century, urbanization of the Miami-Dade County area profoundly affected the environment of the bay. Construction of powerplants, water-treatment plants, and solid-waste sites and large-scale development along the shoreline stressed the ecosystem. Biscayne National Monument was established in 1968 to ?preserve and protect for the education, inspiration, recreation and enjoyment of present and future generations a rare combination of terrestrial, marine, and amphibious life in a tropical setting of great natural beauty? (Public Law 90?606). The monument was enlarged in 1980 and designated a national park.

  20. Potential climate change impacts on a tropical estuary: Hilo Bay, Hawaii

    Science.gov (United States)

    Adolf, J.; LaPinta, J.; Marusek, J.; Pascoe, K.; Pugh, A.

    2016-02-01

    Hilo Bay is a tropical estuarine ecosystem on the northeast (windward) coast of Hawai`i Island that is potentially vulnerable to climate change effects mediated through elevated water temperatures and/or changing rainfall patterns that impact river and groundwater fluxes. Here, we document trends in water temperature, river flow and phytoplankton dynamics in Hilo Bay. Hilo Bay is fed by two major rivers, Wailuku and Honoli`i, both of which have shown long term declines in output over their 85 and 38 year monitoring periods (USGS), respectively. Time series of groundwater inputs to Hilo Bay do not exist, but the average estimated rate rivals that of average river inputs. Daily average Hilo Bay water temperatures have increased at a rate of 0.35 degrees C per year (p Hilo Bay water quality buoy began in 2010, with the warmest temperatures on record recorded Sept 2015. Salinity did not show a trend over this same time period. Phytoplankton showed a pronounced seasonal cycle in Hilo Bay with a long term average of 3.7 mg m-3 and dominance by diatoms that exploit the co-availability of silica and nitrate in this environment. On shorter time scales of days to Hilo Bay salinity, temperature and phytoplankton biomass. Coincidental atmospheric warming, SST warming in the adjacent North Pacific ocean, and declining river flows will likely work together to result in elevated SST in Hilo Bay if observed trends continue. The El Nino event that started this year is expected to exacerbate this warming through reduce river flow and warmer regional SST.

  1. Coastal Acidification as Nutrients Over Enrichment Impact: A Case Study in Ambon Bay, Indonesia

    Directory of Open Access Journals (Sweden)

    Idha Yulia Ikhsani

    2017-05-01

    Full Text Available Ambon Bay is a silled bay on Ambon Island consisting of two regions, Inner Ambon Bay (IAB and Outer Ambon Bay (OAB that are separated by shallow sill. Ambon bay and its surrounding have economically important ecosystem since the utilization for many activities. The bay is affected by anthropogenic impacts associated with urbanization, climate change, and nutrients over enrichment. The “deep water-rich nutrients” from Banda Sea that enter the bay during Southeast monsoon also contribute to this enrichment as well as the nutrients transport from the land. The high concentration of nutrients increases carbon dioxide level and promotes acidifications. There are literatures about nutrients over enrichment in Ambon Bay, however, little is known about coastal acidification as nutrients over enrichment impact. In order to study the effect of nutrients distribution on the acidity of Ambon Bay, the researchers measured pH and concentrations of nutrients {nitrate + nitrite (N+N and Soluble Reactive Phosphate (SRP} from water samples collected in 7 stations on both IAB and OAB during Southeast monsoon. The results showed that in surface water, nutrients concentrations is increased from May to June due to the “deep water flushing” occurrence on May and increased precipitations from May to June. From July to August, the nutrients concentrations on surface layer decreased, due to the decreased precipitations. In column and bottom water, the nutrients concentrations were increased from May to August. While the acidity have reverse pattern from the nutrients, when nutrient concentrations increased the acidity was decreased. From correlation test, pH was not significantly correlated with the concentrations of nutrients on surface water, but showed significantly correlated on column and bottom water. The results indicated that the distribution of nutrients on column and bottom water might be an important environmental factor affecting the acidification of

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

    Directory of Open Access Journals (Sweden)

    Nur Adi Kristanto

    2017-07-01

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

  3. 33 CFR 80.1130 - San Luis Obispo Bay, CA.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Luis Obispo Bay, CA. 80.1130 Section 80.1130 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1130 San Luis Obispo Bay, CA. A line drawn from...

  4. Improved Storm Monitoring and Prediction for the San Francisco Bay Area

    Science.gov (United States)

    Cifelli, R.; Chandrasekar, V.; Anderson, M.; Davis, G.

    2017-12-01

    The Advanced Quantitative Precipitation Information (AQPI) System is a multi-faceted project to improve precipitation and hydrologic monitoring, prediction, and decision support for the San Francisco Bay Area. The Bay Area faces a multitude of threats from extreme events, including disrupted transportation from flooded roads and railroad lines, water management challenges related to storm water, river and reservoir management and storm-related damage demanding emergency response. The threats occur on spatial scales ranging from local communities to the entire region and time scales ranging from hours to days. These challenges will be exacerbated by future sea level rise, more extreme weather events and increased vulnerabilities. AQPI is a collaboration of federal, state and local governments with assistance from the research community. Led by NOAA's Earth System Research Laboratory, in partnership with the Cooperative Institute for Research in the Atmosphere, USGS, and Scripps, AQPI is a four-year effort funded in part by a grant from the California Department of Water Resource's Integrated Regional Water Management Program. The Sonoma County Water Agency is serving as the local sponsor of the project. Other local participants include the Santa Clara Valley Water District, San Francisco Public Utilities Commission, and the Bay Area Flood Protection Agencies Association. AQPI will provide both improved observing capabilities and a suite of numerical forecast models to produce accurate and timely information for benefit of flood management, emergency response, water quality, ecosystem services, water supply and transportation management for the Bay Area. The resulting information will support decision making to mitigate flood risks, secure water supplies, minimize water quality impacts to the Bay from combined sewer overflows, and have improved lead-time on coastal and Bay inundation from extreme storms like Atmospheric Rivers (ARs). The project is expected to

  5. PRIMARILY RESULTS OF PHYTOPLANKTON DNA AND VARIATION TO ENVIRONMENTAL FACTORS IN DURRES`S BAY COASTAL WATERS (ALBANIA

    Directory of Open Access Journals (Sweden)

    Laura Gjyli

    2013-10-01

    Full Text Available After isolation of phytoplankton DNA in coastal waters of Durres Bay, Albania, quantification and analysis of quality were investigated with spectrophotometric analysis. Analysis of UV absorption by the nucleotides provides a simple and accurate estimation of the concentration of nucleic acids in a sample. This method is however limited by the quantity of DNA and the purity of the preparation. Also biotic environment factors as Chlorophyll a and abiotic environment factors as temperature, salinity, pH, dissolved oxygen, turbidity, nitrate, phosphate were investigated to assess DNA quantities in different environment conditions. The Chlorophyll a was studied also to access the level of trophy. The sample stations were: Golem Beach (GB, Channel of Plepa (ChP, Hekurudha Beach (HB, Ex-Fuel Quay in Marine Durres Harbour (EFQ, Water Channel of Durres City (WChDC and Currila Beach (CB. Samples are taken in one meter depth from the water surface. Water samples were collected monthly from April to October 2011. The most abundant stations with phytoplankton DNA are Channel of Plepa and Water Channel of Durres City. This confirms that there are spills of fresh waters, sewage or agricultural water spills, often discharge in coastal waters. Referring Mutliple Regression Analysis and single regression analysis, the association between phytoplankton DNA and environment factors was strong (R2 = 0.75. Basing in single correlation and statistically significance (p-value ≤ 0.05, the enviroment factors that correlated to phytoplankton DNA were pH, salinity and phosphate; explaining thus the variation of total phytoplankton in Durres Bay coastal waters.

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

    Science.gov (United States)

    1990-01-01

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

  7. Safety assessment of a dry storage container drop into irradiated fuel bays

    International Nuclear Information System (INIS)

    Parlatan, Y.; Oh, D.; Arguner, D.; Lei, Q.M.; Kulpa, T.; Bayoumi, M.H.

    2004-01-01

    In Pickering nuclear stations, Dry Storage Containers (DSCs) are employed to transfer used (irradiated) fuel from an irradiated fuel bay to a dry storage facility for interim storage. Each DSC is wet-loaded in the bay water with 4 fuel modules containing up to a total of 384 used fuel bundles that have been out of the reactor core for at least 10 years. Once the DSC is fully loaded, the crane in the bay raises the DSC for spray-wash such that the bottom of the DSC is never more than 2 m above the bay water surface. This paper presents a safety assessment of consequences of an unlikely event that a fully loaded DSC is accidentally dropped into an irradiated fuel bay from the highest possible elevation. Experiments and analyses performed elsewhere show that the DSC drop-generated shock waves will not threaten the structural integrity of an irradiated fuel bay. Therefore, this assessment only assesses the potential damage to the spent fuel bundles in the bay due to pressure transients generated by an accidental DSC drop. A bounding estimate approach has been used to calculate the upper limit of the pressure pulse and the resulting static and dynamic stresses on the fuel sheath. The bounding calculations and relevant experimental results demonstrate that an accidental drop of a fully loaded DSC into an irradiated fuel bay will not cause additional failures of the main fuel inventories stored in modules in the bay water, thus no consequential release of fission products into the bay water. (author)

  8. USGS Tampa Bay Pilot Study

    Science.gov (United States)

    Yates, K.K.; Cronin, T. M.; Crane, M.; Hansen, M.; Nayeghandi, A.; Swarzenski, P.; Edgar, T.; Brooks, G.R.; Suthard, B.; Hine, A.; Locker, S.; Willard, D.A.; Hastings, D.; Flower, B.; Hollander, D.; Larson, R.A.; Smith, K.

    2007-01-01

    Many of the nation's estuaries have been environmentally stressed since the turn of the 20th century and will continue to be impacted in the future. Tampa Bay, one the Gulf of Mexico's largest estuaries, exemplifies the threats that our estuaries face (EPA Report 2001, Tampa Bay Estuary Program-Comprehensive Conservation and Management Plan (TBEP-CCMP)). More than 2 million people live in the Tampa Bay watershed, and the population constitutes to grow. Demand for freshwater resources, conversion of undeveloped areas to resident and industrial uses, increases in storm-water runoff, and increased air pollution from urban and industrial sources are some of the known human activities that impact Tampa Bay. Beginning on 2001, additional anthropogenic modifications began in Tampa Bat including construction of an underwater gas pipeline and a desalinization plant, expansion of existing ports, and increased freshwater withdrawal from three major tributaries to the bay. In January of 2001, the Tampa Bay Estuary Program (TBEP) and its partners identifies a critical need for participation from the U.S. Geological Survey (USGS) in providing multidisciplinary expertise and a regional-scale, integrated science approach to address complex scientific research issue and critical scientific information gaps that are necessary for continued restoration and preservation of Tampa Bay. Tampa Bay stakeholders identified several critical science gaps for which USGS expertise was needed (Yates et al. 2001). These critical science gaps fall under four topical categories (or system components): 1) water and sediment quality, 2) hydrodynamics, 3) geology and geomorphology, and 4) ecosystem structure and function. Scientists and resource managers participating in Tampa Bay studies recognize that it is no longer sufficient to simply examine each of these estuarine system components individually, Rather, the interrelation among system components must be understood to develop conceptual and

  9. 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 ...

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

    Science.gov (United States)

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

    2014-09-15

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

  11. From research to management: A remote sensing based water quality decision matrix (WQDM) for Tampa Bay, Florida

    Science.gov (United States)

    Hu, C.; Le, C.; English, D.; Cannizzaro, J.; Kovach, C.

    2012-12-01

    Significant advances have been made in ocean color remote sensing of water turbidity and water clarity of estuarine waters, yet accurate estimate of the water column chlorophyll-a concentrations (Chla in mg m-3) has been problematic. Here, a novel empirical Chla algorithm was developed and validated for MODIS and SeaWiFS observations between 1998 and 2011 for Tampa Bay, the largest estuary (~1000 km2) in the state of Florida, USA. The algorithm showed robust performance with two independent datasets, with relative mean uncertainties of ~30% and ~50% and RMS uncertainties of ~40% and ~65%,respectively, for Chla ranging between 1.0 and > 30.0 mg m-3. Together with other bio-optical parameters measured from this moderately turbid estuary, these data showed that although the total light absorption in the blue-green wavelengths is dominated by dissolved organic matter, the variability in light penetration (or water clarity) is mainly determined by particulate absorption rather than CDOM absorption. Thus, nutrient reduction management actions that reduce phytoplankton blooms can effectively increase the light availability on the bottom. Long-term Chla time series from SeaWiFS and MODIS observations showed both seasonal and inter-annual variations. On average, river discharge could explain ~60% of the seasonal changes and ~90% of the inter-annual changes, with the latter mainly driven by climate variability (e.g. El Niño and La Niño years) and anomaly events (e.g. tropical cyclones). Significant correlation was found between monthly mean Chla anomalies and monthly Multivariate ENSO Index (MEI) (Pearson correlation coefficient = 0.43, p<0.01, N=147), with high Chla associated with El Niño and lower Chla associated with La Niño. Further, a Water Quality Decision Matrix (WQDM) has been established from the satellite-based Chla and water clarity estimates. The WQDM provides complementary and more reliable information to the existing WQDM based on less synoptic and less

  12. 33 CFR 110.120 - San Luis Obispo Bay, Calif.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Luis Obispo Bay, Calif. 110... ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.120 San Luis Obispo Bay, Calif. (a) Area A-1. Area A-1 is the water area bounded by the San Luis Obispo County wharf, the shoreline, a line drawn...

  13. Spill management strategy for the Chesapeake Bay

    International Nuclear Information System (INIS)

    Butler, H.L.; Chapman, R.S.; Johnson, B.H.

    1990-01-01

    The Chesapeake Bay Program is a unique cooperative effort between state and Federal agencies to restore the health and productivity of America's largest estuary. To assist in addressing specific management issues, a comprehensive three-dimensional, time-varying hydrodynamic and water quality model has ben developed. The Bay modeling strategy will serve as an excellent framework for including submodules to predict the movement, dispersion, and weathering of accidental spills, such as for petroleum products or other chemicals. This paper presents sample results from the Bay application to illustrate the success of the model system in simulating Bay processes. Also, a review of model requirements for successful spill modeling in Chesapeake Bay is presented. Recommendations are given for implementing appropriate spill modules with the Bay model framework and establishing a strategy for model use in addressing management issues

  14. Escherichia coli in the surface waters and in oysters of two cultivations of Guaratuba Bay - Paraná - Brazil

    Directory of Open Access Journals (Sweden)

    Helenita Catharina Dalla-Lana Forcelini

    2013-04-01

    Full Text Available The present work aimed to evaluate the contamination of Escherichia coli in the surface waters and oysters from two cultivations of Guaratuba Bay and to analyze the correlation patterns among the concentrations of E. coli in the waters and in the oysters with the local physical-chemical parameters. Samples were collected in the spring of 2007 and summer, autumn and winter of 2008 from two points of the bay (internal point and external point. From each cultivation and sampling period, 18 oysters were collected. The samples of surface water were collected for the measurement of physical-chemical parameters (pH, salinity, temperature, dissolved oxygen, seston, particulate organic matter and quantification of E. coli. The surface water analyzed in the summer presented the largest most probable number of E. coli, (1,659.22 MPN.100 ml-1 and 958,55 MPN.100 ml-1 at external and internal points, respectively. The oysters from the internal point presented more E. coli, except in the winter sampling. The largest contamination was observed in the spring, at the internal point (979,78 MPN.g-1. The Principal Components Analysis showed direct correlation among the amount of E. coli in the oysters and in the surface water.

  15. NUMERICAL MODELS AS TOOLS TO UNDERSTAND THE DYNAMICS IN BAYS: CASE OF STUDY CHETUMAL BAY, QUINTANA ROO

    Directory of Open Access Journals (Sweden)

    David Avalos-Cueva

    2017-07-01

    Full Text Available In this study performed the simulation of currents generated by the wind on the Bay of Chetumal, Quintana Roo through the use of a stationary shallow-water model. A homogeneous climatic wind was used for the entire Bay, with a velocity of 3m·s-1 , and directions North, South, Northeast, Northwest, East, Southeast, Southwest and West. The results showed a rather complex dynamics in Chetumal Bay, in which important turns were observed in deep areas, with speeds reaching up to 13 cm·s-1 .

  16. Cathodic protection of mild steel and copper in deep waters of the Arabian Sea and Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sawant, S.S.; Venkat, K.; Wagh, A.B.

    Performance of cathodic protection system to mild steel and copper in deep (> 1000 m) oceanic waters of the Arabian Sea and Bay of Bengal has been assessed using aluminium and mild steel sacrificial anodes. The corrosion rates of unprotected metals...

  17. Preliminary estimates of residence times and apparent ages of ground water in the Chesapeake Bay watershed, and water-quality data from a survey of springs

    Science.gov (United States)

    Focazio, Michael J.; Plummer, Niel; Bohlke, John K.; Busenberg, Eurybiades; Bachman, L. Joseph; Powars, David S.

    1998-01-01

    Knowledge of the residence times of the ground-water systems in Chesapeake Bay watershed helps resource managers anticipate potential delays between implementation of land-management practices and any improve-ments in river and estuary water quality. This report presents preliminary estimates of ground-water residence times and apparent ages of water in the shallow aquifers of the Chesapeake Bay watershed. A simple reservoir model, published data, and analyses of spring water were used to estimate residence times and apparent ages of ground-water discharge. Ranges of aquifer hydraulic characteristics throughout the Bay watershed were derived from published literature and were used to estimate ground-water residence times on the basis of a simple reservoir model. Simple combinations of rock type and physiographic province were used to delineate hydrogeomorphic regions (HGMR?s) for the study area. The HGMR?s are used to facilitate organization and display of the data and analyses. Illustrations depicting the relation of aquifer characteristics and associated residence times as a continuum for each HGMR were developed. In this way, the natural variation of aquifer characteristics can be seen graphically by use of data from selected representative studies. Water samples collected in September and November 1996, from 46 springs throughout the watershed were analyzed for chlorofluorocarbons (CFC?s) to estimate the apparent age of ground water. For comparison purposes, apparent ages of water from springs were calculated assuming piston flow. Additi-onal data are given to estimate apparent ages assuming an exponential distribution of ages in spring discharge. Additionally, results from previous studies of CFC-dating of ground water from other springs and wells in the watershed were compiled. The CFC data, and the data on major ions, nutrients, and nitrogen isotopes in the water collected from the 46 springs are included in this report. The apparent ages of water

  18. What caused the rise of water level in the battle of Luermen bay in 1661? Tsunami, Storm surge, or Tide?

    Science.gov (United States)

    Wu, Tso-Ren; Wu, Han; Tsai, Yu-Lin

    2016-04-01

    In 1661, Chinese navy led by General Zheng Chenggong at the end of Ming Dynasty had a naval battle against Netherlands. This battle was not only the first official sea warfare that China confronted the Western world, but also the only naval battle won by Chinese Navy so far. This event was important because it changed the fate of Taiwan until today. One of the critical points that General Zheng won the battle was entering Luermen bay unexpected. Luermen bay was and is an extreme shallow bay with a 2.1m maximum water depth during the high tide, which was not possible for a fleet of 20,000 marines to across. Therefore, no defense was deployed from the Netherlands side. However, plenty of historical literatures mentioned a strange phenomenon that helped Chinese warships entered the Luermen bay, the rise of water level. In this study, we will discuss the possible causes that might rise the water level, e.g. Tsunami, storm surge, and high tide. We analyzed it based on the knowledge of hydrodynamics. We performed the newly developed Impact Intensify Analysis (IIA) for finding the potential tsunami sources, and the COMCOT tsunami model was adopted for the nonlinear scenario simulations, associated with the high resolution bathymetry data. Both earthquake and mudslide tsunamis were inspected. Other than that, we also collected the information of tide and weather for identifying the effects form high tide and storm surge. After the thorough study, a scenario that satisfy most of the descriptions in the historical literatures will be presented. The results will explain the cause of mysterious event that changed the destiny of Taiwan.

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

    Directory of Open Access Journals (Sweden)

    Xiangju Cheng

    2014-01-01

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

  20. A review on the sources and spatial-temporal distributions of Pb in Jiaozhou Bay

    Science.gov (United States)

    Yang, Dongfang; Zhang, Jie; Wang, Ming; Zhu, Sixi; Wu, Yunjie

    2017-12-01

    This paper provided a review on the source, spatial-distribution, temporal variations of Pb in Jiaozhou Bay based on investigation of Pb in surface and waters in different seasons during 1979-1983. The source strengths of Pb sources in Jiaozhou Bay were showing increasing trends, and the pollution level of Pb in this bay was slight or moderate in the early stage of reform and opening-up. Pb contents in the marine bay were mainly determined by the strength and frequency of Pb inputs from human activities, and Pb could be moving from high content areas to low content areas in the ocean interior. Surface waters in the ocean was polluted by human activities, and bottom waters was polluted by means of vertical water’s effect. The process of spatial distribution of Pb in waters was including three steps, i.e., 1), Pb was transferring to surface waters in the bay, 2) Pb was transferring to surface waters, and 3) Pb was transferring to and accumulating in bottom waters.

  1. [Pollution by heavy metals in the petrochemical sewage waters of the sea area of Daya Bay and assessment on potential ecological risks].

    Science.gov (United States)

    Xu, Shan-Nan; Li, Chun-Hou; Xu, Jiao-Jiao; Xiao, Ya-Yuan; Lin, Lin; Huang, Xiao-Ping

    2014-06-01

    This study aimed to gain a clear understanding on the status of pollution by heavy metals in the petrochemical sewage and the potential ecological risk caused by heavy metal pollution in the sea area of Daya Bay. The contents and spatial distributions of heavy metals including Zn, Pb, Cu, Cd, Cr, As and Hg in seawater, sediment and fishes collected from Daya Bay were analyzed. The comprehensive pollution index (CPI) and ecological risk indexes (ERIs) were used to evaluate the contaminated severity and potential ecological risks of heavy metals in seawater and sediment. The results showed that the contents of these heavy metals, except for those of Zn and Pb, in several stations set in Daya Bay from 2011 to 2012 were relatively low, which were lower than the quality standard of class I according to the China National Standard Criteria for Seawater Quality, suggesting that the seawater in Daya Bay has not been polluted yet by these heavy metals. The average CPI of heavy metals in seawater during flooding season (0.72) was higher than that during dry season (0.38) whereas the average CPI of heavy metals in sediment during dry season (7.77) was higher than that during flooding season (5.70). Hg was found to be the primary contaminating heavy metal in sediment during dry season, which was followed by As and Zn whereas during flooding season, Hg was the primary contaminating metal in sediment, followed by Zn and Cu. The contents of these 7 heavy metals in fishes collected from the surveyed areas were lower than those of the standard requirements. A correlation analysis indicated that there were significant differences in the correlations between the midst of the heavy metals in sea water and the different periods. The ERIs of heavy metals in sediment during dry season (129.20) was higher than that during flooding season (102.86), and 25% of the sampling sites among all stations were under the risk of high-level alarm. The potential ERIs of heavy metals in sediment in

  2. South Bay Salt Pond Tidal Marsh Restoration at Pond A17 Project

    Science.gov (United States)

    Information about the SFBWQP South Bay Salt Pond Tidal Marsh Restoration at Pond A17 Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

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

    Science.gov (United States)

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

    2017-01-30

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

  4. Topobathymetric model of Mobile Bay, Alabama

    Science.gov (United States)

    Danielson, Jeffrey J.; Brock, John C.; Howard, Daniel M.; Gesch, Dean B.; Bonisteel-Cormier, Jamie M.; Travers, Laurinda J.

    2013-01-01

    Topobathymetric Digital Elevation Models (DEMs) are a merged rendering of both topography (land elevation) and bathymetry (water depth) that provides a seamless elevation product useful for inundation mapping, as well as for other earth science applications, such as the development of sediment-transport, sea-level rise, and storm-surge models. This 1/9-arc-second (approximately 3 meters) resolution model of Mobile Bay, Alabama was developed using multiple topographic and bathymetric datasets, collected on different dates. The topographic data were obtained primarily from the U.S. Geological Survey (USGS) National Elevation Dataset (NED) (http://ned.usgs.gov/) at 1/9-arc-second resolution; USGS Experimental Advanced Airborne Research Lidar (EAARL) data (2 meters) (http://pubs.usgs.gov/ds/400/); and topographic lidar data (2 meters) and Compact Hydrographic Airborne Rapid Total Survey (CHARTS) lidar data (2 meters) from the U.S. Army Corps of Engineers (USACE) (http://www.csc.noaa.gov/digitalcoast/data/coastallidar/). Bathymetry was derived from digital soundings obtained from the National Oceanic and Atmospheric Administration’s (NOAA) National Geophysical Data Center (NGDC) (http://www.ngdc.noaa.gov/mgg/geodas/geodas.html) and from water-penetrating lidar sources, such as EAARL and CHARTS. Mobile Bay is ecologically important as it is the fourth largest estuary in the United States. The Mobile and Tensaw Rivers drain into the bay at the northern end with the bay emptying into the Gulf of Mexico at the southern end. Dauphin Island (a barrier island) and the Fort Morgan Peninsula form the mouth of Mobile Bay. Mobile Bay is 31 miles (50 kilometers) long by a maximum width of 24 miles (39 kilometers) with a total area of 413 square miles (1,070 square kilometers). The vertical datum of the Mobile Bay topobathymetric model is the North American Vertical Datum of 1988 (NAVD 88). All the topographic datasets were originally referenced to NAVD 88 and no transformations

  5. 33 CFR 117.753 - Ship Channel, Great Egg Harbor Bay.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ship Channel, Great Egg Harbor Bay. 117.753 Section 117.753 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.753 Ship Channel, Great Egg Harbor Bay. The draw of the S52 (Ship...

  6. Chesapeake Bay baseline data acquisition, toxics in the Chesapeake Bay. Final preliminary report, 1946-78

    International Nuclear Information System (INIS)

    1978-07-01

    This report identifies researchers, research activities, and data files applicable to the Chesapeake Bay estuarine system. The identified data were generated after 1973 on the following: submerged aquatic vegetation, shellfish bed closures, eutrophication, toxics accumulation in the food chain, dredging and spoil disposal, hydrologic modifications, modification of fisheries, shoreline erosion, wetlands alterations, and the effects of boating and shipping on water quality. Major past and current program monitoring in the Bay and its tributaries are summarized according to frequency

  7. Rising air and stream-water temperatures in Chesapeake Bay region, USA

    Science.gov (United States)

    Rice, Karen C.; Jastram, John D.

    2015-01-01

    Monthly mean air temperature (AT) at 85 sites and instantaneous stream-water temperature (WT) at 129 sites for 1960–2010 are examined for the mid-Atlantic region, USA. Temperature anomalies for two periods, 1961–1985 and 1985–2010, relative to the climate normal period of 1971–2000, indicate that the latter period was statistically significantly warmer than the former for both mean AT and WT. Statistically significant temporal trends across the region of 0.023 °C per year for AT and 0.028 °C per year for WT are detected using simple linear regression. Sensitivity analyses show that the irregularly sampled WT data are appropriate for trend analyses, resulting in conservative estimates of trend magnitude. Relations between 190 landscape factors and significant trends in AT-WT relations are examined using principal components analysis. Measures of major dams and deciduous forest are correlated with WT increasing slower than AT, whereas agriculture in the absence of major dams is correlated with WT increasing faster than AT. Increasing WT trends are detected despite increasing trends in streamflow in the northern part of the study area. Continued warming of contributing streams to Chesapeake Bay likely will result in shifts in distributions of aquatic biota and contribute to worsened eutrophic conditions in the bay and its estuaries.

  8. The dynamics of İzmir Bay under the effects of wind and thermohaline forces

    Science.gov (United States)

    Sayın, Erdem; Eronat, Canan

    2018-04-01

    The dominant circulation pattern of İzmir Bay on the Aegean Sea coast of Turkey is studied taking into consideration the influence of wind and thermohaline forces. İzmir Bay is discussed by subdividing the bay into outer, middle and inner areas. Wind is the most important driving force in the İzmir coastal area. There are also thermohaline forces due to the existence of water types of different physical properties in the bay. In contrast to the two-layer stratification during summer, a homogeneous water column exists in winter. The free surface version of the Princeton model (Killworth's 3-D general circulation model) is applied, with the input data obtained through the measurements made by the research vessel K. Piri Reis. As a result of the simulations with artificial wind, the strong consistent wind generates circulation patterns independent of the seasonal stratification in the bay. Wind-driven circulation causes cyclonic or anticyclonic movements in the middle bay where the distinct İzmir Bay Water (IBW) forms. Cyclonic movement takes place under the influence of southerly and westerly winds. On the other hand, northerly and easterly winds cause an anticyclonic movement in the middle bay. The outer and inner bay also have the wind-driven recirculation patterns expected.

  9. Measuring Macrobenthos Biodiversity at Oyster Aquaculture Sites in the Delaware Inland Bays

    Science.gov (United States)

    Fuoco, M. J.; Ozbay, G.

    2016-12-01

    The Delaware Inland Bays consists of three shallow coastal bays located in the southern portion of Delaware. Anthropogenic activities have led to the degradation of water quality, because the bays are surrounded by highly developed areas and have low flushing rates. This results in loss of biodiversity and abundance of organisms. Ongoing degradation of the bays has led to a dramatic decline in local oyster populations since the late 1800s. Oysters are keystone species, which provide habitats for organisms and help to improve water quality. This study aims to find if the introduction of oyster aquaculture improves local biodiversity and abundance of macrobenthos. The study was conducted in Rehoboth Bay, Indian River Bay and Little Assawoman Bay. Aquaculture gear was placed at one location in each of the bays and 24 sediment core samples were taken once a month. From these core samples all worms were fixed and stained in a 10% Formalin Rose Bengal solution and preserved in 70% Ethanol for later identification. Stable carbon and nitrogen isotope analysis of oyster tissue will also be performed to assess the health of the bay. The goals of this research are to better understand the role of oyster aquaculture in restoring the viability and health of the Delaware Inland Bays.

  10. Variable influx of West Greenland Current water into the Labrador Current through the last 8000 years, based on a multiproxy study from Trinity Bay, NE Newfoundland

    DEFF Research Database (Denmark)

    Sheldon, Christina; Seidenkrantz, Marit-Solveig; Frandsen, Paul

    2015-01-01

    This multi-proxy study of marine sediment gravity core AI07-06G from Trinity Bay, Newfoundland, recorded changes in the strength of the Labrador Current (LC) during the Holocene. From ca. 8-5 cal kyr BP, Trinity Bay's seafloor was influenced by cooled Atlantic water derived from the West Greenland...

  11. Summary of oceanographic and water-quality measurements in Barnegat Bay, New Jersey, 2014–15

    Science.gov (United States)

    Suttles, Steven E.; Ganju, Neil K.; Montgomery, Ellyn T.; Dickhudt, Patrick J.; Borden, Jonathan; Brosnahan, Sandra M.; Martini, Marinna A.

    2016-09-26

    Scientists and technical support staff from the U.S. Geological Survey measured suspended-sediment concentrations, currents, pressure, and water temperature in two tidal creeks, Reedy Creek and Dinner Creek, in Barnegat Bay, New Jersey, from August 11, 2014, to July 10, 2015 as part of the Estuarine Physical Response to Storms project (GS2–2D). The oceanographic and water-quality data quantify suspended-sediment transport in Reedy Creek and Dinner Creek, which are part of a tidal marsh wetland complex in the Edwin B. Forsythe National Wildlife Refuge. All deployed instruments were removed between January 7, 2015, and April 14, 2015, to avoid damage by ice.

  12. Pilot Water Quality Monitoring Station in Dublin Bay : North Bank Station (NBMS), MATSIS Project Part I

    OpenAIRE

    O'Donnell, Garvan; Joyce, Eileen; Silke, Joe; O'Boyle, Shane; McGovern, Evin

    2008-01-01

    This report describes the pilot development of an autonomous monitoring station in Dublin Bay and validation of the system. It presents results from initial deployments. Sensors were deployed for testing, including an optical sensor for measuring nitrate and sensors for measurement of salinity, temperature, fluorescence and dissolved oxygen. Automated water samplers enabled periodic, remote triggered and event triggered sampling for nutrient and phytoplankton samples.

  13. Analysis of Level of Technogenic Impact on Water Area of Uglovoy Bay

    Science.gov (United States)

    Petukhov, V. I.; Petrova, E. A.; Losev, O. V.

    2017-11-01

    Industrial effluent discharge and man-induced soil fills play a decisive role in increased pollutant concentrations. Several areas which are unfavorable in terms of the heavy metal and oil product content have been identified by the environmental monitoring results in the Uglovoy Bay in February 2015. Maximum permissible concentrations (MPC) of heavy metals and oil products were exceeded in the northeastern part of the Uglovoy Bay in locations where the Peschanka River and the Aerodromnaya River drain into the sea. Integral heavy-metal index calculations showed that this area is the most polluted in the Uglovoy Bay. Other significantly polluted areas were identified off the Zima Yuzhnaya settlement in the mouth of the bay and in vicinity of the low-level bridge.

  14. 33 CFR 334.310 - Chesapeake Bay, Lynnhaven Roads; navy amphibious training area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Chesapeake Bay, Lynnhaven Roads; navy amphibious training area. 334.310 Section 334.310 Navigation and Navigable Waters CORPS OF....310 Chesapeake Bay, Lynnhaven Roads; navy amphibious training area. (a) The restricted area. Beginning...

  15. Metal concentrations in Kandalaksha Bay, White Sea (Russia) following the spring snowmelt

    International Nuclear Information System (INIS)

    Cobelo-Garcia, A.; Millward, G.E.; Prego, R.; Lukashin, V.

    2006-01-01

    Elevated concentrations of dissolved and particulate Cd, Cu, Pb and Zn have been determined in the waters of Kandalaksha Bay (White Sea, Russia), following the ice melt in the spring of 2000. Dissolved metal maxima in the surface waters were observed at some stations and concentrations generally decreased with depth. The suspended particulate matter (SPM) comprised a non-lithogenic fraction in the range 12-83%, and had elevated metal concentrations that showed no trend with depth or salinity and was compositionally distinct from the sediments. A log-linear relationship existed between the concentrations of metals in sediments and in SPM and their respective Al concentrations, indicating a source of metal-rich particles, with low Al content, to the Bay. The results suggest that Kandalaksha Bay has been impacted by industrial activity on the Kola Peninsula and that restricted water exchange will hinder its recovery from metal contamination. - Elevated dissolved and particulate metal concentrations have been determined in the water column of Kandalaksha Bay, White Sea (Russia)

  16. Wind-Driven Waves in Tampa Bay, Florida

    Science.gov (United States)

    Gilbert, S. A.; Meyers, S. D.; Luther, M. E.

    2002-12-01

    Turbidity and nutrient flux due to sediment resuspension by waves and currents are important factors controlling water quality in Tampa Bay. During December 2001 and January 2002, four Sea Bird Electronics SeaGauge wave and tide recorders were deployed in Tampa Bay in each major bay segment. Since May 2002, a SeaGauge has been continuously deployed at a site in middle Tampa Bay as a component of the Bay Regional Atmospheric Chemistry Experiment (BRACE). Initial results for the summer 2002 data indicate that significant wave height is linearly dependent on wind speed and direction over a range of 1 to 12 m/s. The data were divided into four groups according to wind direction. Wave height dependence on wind speed was examined for each group. Both northeasterly and southwesterly winds force significant wave heights that are about 30% larger than those for northwesterly and southeasterly winds. This difference is explained by variations in fetch due to basin shape. Comparisons are made between these observations and the results of a SWAN-based model of Tampa Bay. The SWAN wave model is coupled to a three-dimensional circulation model and computes wave spectra at each model grid cell under observed wind conditions and modeled water velocity. When SWAN is run without dissipation, the model results are generally similar in wave period but about 25%-50% higher in significant wave height than the observations. The impact of various dissipation mechanisms such as bottom drag and whitecapping on the wave state is being investigated. Preliminary analyses on winter data give similar results.

  17. Recent research on the hydrodynamics of the Sacramento - San Joaquin River Delta and north San Francisco Bay

    Science.gov (United States)

    Burau, J.R.; Monismith, S.G.; Stacey, M.T.; Oltmann, R.N.; Lacy, J.R.; Schoellhamer, D.H.

    1999-01-01

    This article presents an overview of recent findings from hydrodynamic research on circulation and mixing in the Sacramento-San Joaquin Delta (Delta) (Figure 1) and North San Francisco Bay (North Bay) (Figure 2). For the purposes of this article, North Bay includes San Pablo Bay, Carquinez Strait, and Suisun Bay. The findings presented are those gained from field studies carried out by the U.S. Geological Survey (USGS), as part of the Interagency Ecological Program (IEP), and Stanford University beginning about 1993. The premise behind these studies was that a basic understanding of circulation and mixing patterns in the Bay and Delta is an essential part of understanding how biota and water quality are affected by natural hydrologic variability, water appropriation, and development activities. Data collected for the field studies described in this article have significantly improved our understanding of Bay and Delta hydrodynamics. Measured flows ,in the Delta have provided valuable information on how water moves through the Delta's network of channels and how export pumping affects flows. Studies of the shallows and shallow-channel exchange processes conducted in Honker Bay have shown that the water residence time in Honker Bay is much shorter than previously reported (on the order of hours to several tidal cycles instead ofweeks). Suisun Bay studies have provided data on hydrodynamic transport and accumulation mechanisms that operate primarily in the channels. The Suisun Bay studies have caused us to revise our understanding of residual circulation in the channels of North Bay and of "entrapment" mechanisms in the low salinity zone. Finally, detailed tidal and residual (tidally averaged) time-scale studies of the mechanisms that control gravitational circulation in the estuary show that density-driven transport in the channels is governed by turbulence time-scale (seconds) interactions between the mean flow and stratification. The hydrodynamic research

  18. Nelson River and Hudson Bay

    Science.gov (United States)

    2002-01-01

    Rivers that empty into large bodies of water can have a significant impact on the thawing of nearshore winter ice. This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from May 18, 2001, shows the Nelson River emptying spring runoff from the Manitoba province to the south into the southwestern corner of Canada's Hudson Bay. The warmer waters from more southern latitudes hasten melting of ice near the shore, though some still remained, perhaps because in shallow coastal waters, the ice could have been anchored to the bottom. High volumes of sediment in the runoff turned the inflow brown, and the rim of the retreating ice has taken on a dirty appearance even far to the east of the river's entrance into the Bay. The sediment would have further hastened the melting of the ice because its darker color would have absorbed more solar radiation than cleaner, whiter ice. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  19. Gas exchange rates across the sediment-water andd air-water interfaces in south San Francisco Bay

    International Nuclear Information System (INIS)

    Hartman, B.; Hammond, D.E.

    1984-01-01

    Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainity of the determinations, about 20%. The annual average of bethic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water inteface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2--6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models

  20. Gas exchange rates across the sediment-water and air-water interfaces in south San Francisco Bay

    Science.gov (United States)

    Hartman, Blayne; Hammond, Douglas E.

    1984-01-01

    Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainty of the determinations, about 20%. The annual average of benthic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water interface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2–6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models.

  1. Coincident patterns of waste water suspended solids reduction, water transparency increase and chlorophyll decline in Narragansett Bay.

    Science.gov (United States)

    Borkman, David G; Smayda, Theodore J

    2016-06-15

    Dramatic changes occurred in Narragansett Bay during the 1980s: water clarity increased, while phytoplankton abundance and chlorophyll concentration decreased. We examine how changes in total suspended solids (TSS) loading from wastewater treatment plants may have influenced this decline in phytoplankton chlorophyll. TSS loading, light and phytoplankton observations were compiled and a light- and temperature-dependent Skeletonema-based phytoplankton growth model was applied to evaluate chlorophyll supported by TSS nitrogen during 1983-1995. TSS loading declined 75% from ~0.60×10(6)kgmonth(-1) to ~0.15×10(6)kgmonth(-1) during 1983-1995. Model results indicate that nitrogen reduction related to TSS reduction was minor and explained a small fraction (~15%) of the long-term chlorophyll decline. The decline in NBay TSS loading appears to have increased water clarity and in situ irradiance and contributed to the long-term chlorophyll decline by inducing a physiological response of a ~20% reduction in chlorophyll per cell. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. 33 CFR 110.31 - Hull Bay and Allerton Harbor at Hull, Mass.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Hull Bay and Allerton Harbor at Hull, Mass. 110.31 Section 110.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.31 Hull Bay and Allerton Harbor at...

  3. San Antonio Bay 1986-1989

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The effect of salinity on utilization of shallow-water nursery habitats by aquatic fauna was assessed in San Antonio Bay, Texas. Overall, 272 samples were collected...

  4. Development of a Hydrodynamic and Transport model of Bellingham Bay in Support of Nearshore Habitat Restoration

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Taiping; Yang, Zhaoqing; Khangaonkar, Tarang

    2010-04-22

    In this study, a hydrodynamic model based on the unstructured-grid finite volume coastal ocean model (FVCOM) was developed for Bellingham Bay, Washington. The model simulates water surface elevation, velocity, temperature, and salinity in a three-dimensional domain that covers the entire Bellingham Bay and adjacent water bodies, including Lummi Bay, Samish Bay, Padilla Bay, and Rosario Strait. The model was developed using Pacific Northwest National Laboratory’s high-resolution Puget Sound and Northwest Straits circulation and transport model. A sub-model grid for Bellingham Bay and adjacent coastal waters was extracted from the Puget Sound model and refined in Bellingham Bay using bathymetric light detection and ranging (LIDAR) and river channel cross-section data. The model uses tides, river inflows, and meteorological inputs to predict water surface elevations, currents, salinity, and temperature. A tidal open boundary condition was specified using standard National Oceanic and Atmospheric Administration (NOAA) predictions. Temperature and salinity open boundary conditions were specified based on observed data. Meteorological forcing (wind, solar radiation, and net surface heat flux) was obtained from NOAA real observations and National Center for Environmental Prediction North American Regional Analysis outputs. The model was run in parallel with 48 cores using a time step of 2.5 seconds. It took 18 hours of cpu time to complete 26 days of simulation. The model was calibrated with oceanographic field data for the period of 6/1/2009 to 6/26/2009. These data were collected specifically for the purpose of model development and calibration. They include time series of water-surface elevation, currents, temperature, and salinity as well as temperature and salinity profiles during instrument deployment and retrieval. Comparisons between model predictions and field observations show an overall reasonable agreement in both temporal and spatial scales. Comparisons of

  5. Intense Undular Bores on the Autumn Pycnocline of Shelf Waters of the Peter the Great Bay (Sea of Japan)

    Science.gov (United States)

    Dolgikh, G. I.; Novotryasov, V. V.; Yaroshchuk, I. O.; Permyakov, M. S.

    2018-03-01

    The results of field observations of an internal undular bore that were performed in a coastal zone of constant depth in the Sea of Japan are presented. A hydrodynamic model of undular bores is discussed according to which the recorded disturbances of the water medium are an experimental prototype of strongly nonlinear (intense) internal undular bores on the pycnocline of shelf waters of Peter the Great Bay with an intensity close to the limit.

  6. Corrosion of metals and alloys in the coastal and deep waters of the Arabian Sea and the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sawant, S.S.; Venkat, K.; Wagh, A.B.

    Corrosion rate of mild steel (MS), stainless steel (SS), copper, brass and cupro-nickel has been determinEd. by exposing metallic coupons in coastal and oceanic waters of the Arabian Sea and Bay of Bengal. Amongst the metals and alloys under study...

  7. Intrusion of the Bay of Bengal water into the Arabian Sea during winter monsoon and associated chemical and biological response

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Narvekar, J.; Kumar, A.; Shaji, C.; Anand, P.; Sabu, P.; Rijomon, G.; Josia, J.; Jayaraj, K.A.; Radhika, A.; Nair, K.K.C.

    off. The hydrological imbalance thus created on an annual scale will have to be balanced by the inter-basin exchange. In winter this happens through the intrusion of Bay of Bengal waters into the Arabian Sea, when the southward flowing East India...

  8. Contaminant profiles for surface water, sediment, flora and fauna associated with the mangrove fringe along middle and lower East Tampa Bay

    Science.gov (United States)

    Contaminant concentrations are reported for surface water, sediment, seagrass, mangroves, Florida Crown conch, blue crabs and fish collected during 2010-2011 from the mangrove fringe along eastern Tampa Bay. Concentrations of trace metals, chlorinated pesticides, atrazine, total ...

  9. Chesapeake Bay recovery and factors affecting trends: Long-termmonitoring, indicators, and insights

    Science.gov (United States)

    Tango, Peter J.; Batiuk, Richard A.

    2016-01-01

    Monitoring the outcome of restoration efforts is the only way to identify the status of a recovery and the most effective management strategies. In this paper, we discuss Chesapeake Bay and watershed recovery and factors influencing water quality trends. For over 30 years, the Chesapeake Bay Program Partnership’s long-term tidal and watershed water quality monitoring networks have measured physical, chemical and biological parameters throughout the bay and its surrounding watershed underpinning an adaptive management process to drive ecosystem recovery. There are many natural and anthropogenic factors operating and interacting to affect the watershed and bay water quality recovery responses to management actions. Across habitats and indicators, the bay and its watershed continue to express a diverse spatial and temporal fabric of multiscale conditions, stressors and trends that show a range of health conditions and impairments, as well as evidence of progress and degradation. Recurrent independent reviews of the monitoring program have driven a culture of continued adaptation of the monitoring networks to reflect ever evolving management information needs. The adherence to bay and watershed-wide consistent monitoring protocols provides monitoring data supporting analyses and development of scientific syntheses that underpin indicator and model development, regulatory assessments, targeting of management actions, evaluation of management effectiveness, and directing of priorities and policies.

  10. Mussels as a bio-indicator of the environmental quality of the coastal water of the Boka Kotorska Bay (Montenegro

    Directory of Open Access Journals (Sweden)

    MIHAJLO JOVIĆ

    2011-06-01

    Full Text Available The Mediterranean blue mussel Mytilus galloprovincialis was used as a pollution level indicator in the Boka Kotorska Bay of the southeastern Adriatic on the Montenegrin coast. The ever-increasing urbanization and industrialization, combined with a poor sewage system, an increase in both marine and inland traffic, as well as insufficient water circulation in the Bay itself have resulted in some level of pollution. Since heavy metals are extremely toxic and do not easily undergo biodecomposition, the results of this study supply valuable information concerning the metal pollution of the marine environment in Boka Kotorska Bay. The concentrations of the investigated metals and non-metals accumulated in the mussels were determined during the fall of 2007 using Atomic Absorption Spectroscopy (AAS for Cr, Mn, Co, Ni, Cu, Cd, Hg, Pb, Sn and V, and Energy Dispersive X-ray Fluorescence (ED–XRF to determine the concentrations of Fe, Zn, Si, P, S, Cl, K and Ca. ED–XRF was also used to determine the levels of non-metals and elements present in high concentrations. Comparing the data from this study in relation to data from other regions for Mytilus galloprovincialis, the mussel sampled from the Boka Kotorska Bay showed a moderate level of pollution.

  11. Cold seeps in Monterey Bay, California: Geochemistry of pore waters and relationship to benthic foraminiferal calcite

    International Nuclear Information System (INIS)

    Gieskes, Joris; Rathburn, Anthony E.; Martin, Jonathan B.; Perez, M. Elena; Mahn, Chris; Bernhard, Joan M.; Day, Shelley

    2011-01-01

    Highlights: → We describe the geochemistry of pore waters in the Clam Flats area of Monterey Bay. → The geochemical data are compared with the δ 13 C chemistry of benthic foraminifera. → Living foraminifera indicate little effects of pore water low δ 13 C (DIC) in the clam bed. → This phenomenon and its implications are discussed in detail. → Implications with regards to paleo-methane seepage are discussed. - Abstract: An extensive geochemical and biogeochemical examination of CH 4 seeps in the Clam Flats area of Monterey Bay provides insight into the character of relationships between seep geochemistry and benthic foraminiferal geochemistry. The area is characterized by sulfide-rich fluids. Sulfide increases are associated with large increases in alkalinity, as well as small decreases in dissolved Ca and Mg. In addition, only small increases in NH 4 are observed, but values of δ 13 C of dissolved inorganic C are as low as -60 per mille at shallow depths ( 4 , which is transported upward by slow seepage of pore fluids. The geochemistry of the pore fluids should be relevant to the geochemistry of the carbonate tests of living and dead foraminifera. However, a profound disequilibrium of approximately an order of magnitude occurs between the δ 13 C values of stained (cytoplasm-containing) foraminiferal carbonate and the C isotope values of ambient pore water dissolved inorganic C. Reasons are unclear for this isotopic disequilibrium, but have important implications for interpretations of foraminiferal carbonate as a paleoenvironmental proxy. Much fine scale work is needed to fully understand the relationships between the biogeochemistry of benthic foraminifera and the geochemistry of the pore waters where they live.

  12. Sediment Pore Water Ammonium Concentrations in Old Tampa Bay as Determined by the Diffusive Equilibration in Thin Films (DET) Technique

    Science.gov (United States)

    Increased nitrogen loading, associated with rapid human population growth, was thought to be a major driver of Tampa Bay water quality degradation in the decades immediately after the Second World War. Improvements in wastewater treatment in the early 1980s led to marked reductio...

  13. Spatial-temporal migration laws of Cd in Jiaozhou Bay

    Science.gov (United States)

    Yang, Dongfang; Li, Haixia; Zhang, Xiaolong; Wang, Qi; Miao, Zhenqing

    2018-02-01

    Many marine bays have been polluted by various pollutants, and understanding the migration laws is essential to scientific research and pollution control. This paper analyzed the spatial and temporal migration laws of Cd in waters in Jiaozhou Bay during 1979—1983. Results showed that there were twenty spatial-temporal migration law for the migration processes of Cd. These laws were helpful for better understanding the migration of Cd in marine bay, providing basis for scientific research and pollution control.

  14. Transport and potential vorticity in the Bay of Bengal during the southwest monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, V.S.N.; Murty, C.S.; Sarma, Y.V.B.; Rao, D.P.; Sastry, J.S.; Rao, G.R.L.

    Current (EBC) contributed to an influx of 3.5 x 10 sup(6 m sup(3/s water respectively. The influence of overlying less saline, fresher water at the northern Bay: Ekman suction due to the wind stress curl in the central Bay; and the east-flowing IMC...

  15. Coastal upwelling by wind-driven forcing in Jervis Bay, New South Wales: A numerical study for 2011

    Science.gov (United States)

    Sun, Youn-Jong; Jalón-Rojas, Isabel; Wang, Xiao Hua; Jiang, Donghui

    2018-06-01

    The Princeton Ocean Model (POM) was used to investigate an upwelling event in Jervis Bay, New South Wales (SE Australia), with varying wind directions and strengths. The POM was adopted with a downscaling approach for the regional ocean model one-way nested to a global ocean model. The upwelling event was detected from the observed wind data and satellite sea surface temperature images. The validated model reproduced the upwelling event showing the input of bottom cold water driven by wind to the bay, its subsequent deflection to the south, and its outcropping to the surface along the west and south coasts. Nevertheless, the behavior of the bottom water that intruded into the bay varied with different wind directions and strengths. Upwelling-favorable wind directions for flushing efficiency within the bay were ranked in the following order: N (0°; northerly) > NNE (30°; northeasterly) > NW (315°; northwesterly) > NE (45°; northeasterly) > ENE (60°; northeasterly). Increasing wind strengths also enhance cold water penetration and water exchange. It was determined that wind-driven downwelling within the bay, which occurred with NNE, NE and ENE winds, played a key role in blocking the intrusion of the cold water upwelled through the bay entrance. A northerly wind stress higher than 0.3 N m-2 was required for the cold water to reach the northern innermost bay.

  16. Interaction between continental and estuarine waters in the wetlands of the northern coastal plain of Samborombón Bay, Argentina

    International Nuclear Information System (INIS)

    Carol, Eleonora; Mas-Pla, Josep; Kruse, Eduardo

    2013-01-01

    Highlights: • Inland and estuarine water flows define wetland hydrology on the Samborombón Bay. • Hydrochemistry in shell-ridges and tidal plains is due to water–rock interaction. • Mixing, evaporation and halite dissolution determine salinity in marshes. • Water flow from the shell-ridges control the overall wetland water quality. • These wetlands are complex hydrological systems with vulnerable water resources. - Abstract: On the Samborombón Bay coastline, located in the Río de la Plata estuary in Buenos Aires province (Argentina), a complex hydrological system has developed at the interface between continental and estuarine water, where significant wetlands develop. The main hydrogeological units, namely the shell ridges, the tidal plain and the marsh areas, have been identified using geomorphological criteria. Water table, hydrochemical and isotopic data have been used to determine their hydrological features, as well as those of the streams and canals. Evaporation processes, in particular, have been considered when depicting chemical and isotopic changes in surface waters in streams and marsh areas. The shell ridges represent a hydrogeological unit in which rainwater is stored, constituting a lens-shaped freshwater aquifer. In this unit, just as in the tidal plain, carbonate dissolution and ion exchange are the main processes regulating water chemistry. On the other hand, in the marsh and surface waters, processes such as mixing with estuarine water and evaporation predominate. These processes control water fluxes and the salinity of the wetland areas and, consequently, their ability to preserve the existing biodiversity. This study shows the importance of knowledge of hydrochemical processes in any proposal concerning the management and preservation of this type of wetland

  17. Geoelectric imaging for saline water intrusion in Geopark zone of Ciletuh Bay, Indonesia

    Science.gov (United States)

    Ardi, N. D.; Iryanti, M.; Asmoro, C. P.; Yusuf, A.; Sundana, A. N. A.; Safura, H. Y.; Fitri, M.; Anggraeni, M.; Kurniawan, R.; Afrianti, R.; Sumarni

    2018-05-01

    Saline water intrusion in estuary is an urgent ecological encounter across the world. The Ciletuh Bay, located in the southern Sukabumi district, is an area with high cultivated potential becoming one of the most important geology tourism zones in Indonesia. However, salt water intrusion along the creek is a natural spectacle that disturbs the economic growth of the whole region. This research was intended at plotting the subsurface level of saltwater interventions into aquifers at the northern part of Ciletuh creek, Indonesia. The study implemented geoelectric imaging methods. 37 imaging datum were acquired using Wenner array configuration. The saline water were identified across the study area. The result of two dimensional cross-sectional resistivity shows that there is an indication of sea content in our measured soil, i.e. the smallest resistivity value is 0.579 Ωm found at a depth of 12.4 m to 19.8 m at a track length of 35 m to 60 m is categorized in the clayey which shows low groundwater quality. However, when compared with the results of direct observation of groundwater from the wells of residents, the water obtained is brackish water. A water chemistry test is conducted to ascertain the initial results of this method so that a potential sea intrusion potential map can be interpreted more clearly. This can consequently help as an extrapolative model to define depth to saline water at any site within the saline water zone in the study area.

  18. Status, trends, and changes in freshwater inflows to bay systems in the Corpus Christi Bay National Estuary Program study area

    Science.gov (United States)

    Asquith, W.H.; Mosier, J. G.; Bush, P.W.

    1997-01-01

    This report presents the results of a study to quantify current (1983–93) mean freshwater inflows to the six bay systems (open water and wetlands) in the Corpus Christi Bay National Estuary Program study area, to test for historical temporal trends in inflows, and to quantify historical and projected changes in inflows. The report also addresses the adequacy of existing data to estimate freshwater inflows.

  19. Virgin Islands: Coral Bay Watershed Management (A Former EPA CARE Project)

    Science.gov (United States)

    The Coral Bay Watershed Management is a recipient of the Level II CARE cooperative agreement to continue and expand its collective efforts to stop erosion, sediment, and storm-water pollution of Coral Bay, improve solid waste management,

  20. Fouling issues within CANDU fuel bay purification systems

    International Nuclear Information System (INIS)

    Angell, P.; Murray, J.

    2003-01-01

    Similar to all nuclear power stations, CANDU stations store their spent fuel in large open fuel bays to allow the fuel bundles to cool down. Over the years there have been a number of minor issues relating to the operation of the fuel bays, and the annual operational and maintenance costs to the stations are in the order of $1-2M. Ontario Power Generation (OPG) stations have been treating the fuel bays of their CANDU stations with hydrogen peroxide. While this treatment has been effective for the control of microbial corrosion and algal problems, an ongoing problem with the rapid plugging of the purification system filters and the presence of a thin translucent film on the surface of the water has been reported. Analysis suggested that the translucent film was of biological origin and initially it was suspected as being responsible for the plugging of the filters. Samples of the bay water, translucent film and filters were collected for microbial analysis. From all samples a number of bacterial species was isolated, all of which had the enzyme catalase that is responsible for the microbial breakdown of hydrogen peroxide, and many of the isolates were found to be capable of producing extracellular polymeric substance (slime). Observation of the filter revealed that no slime layer was present on the outer surface of the filter. This suggested that the plugging was not the result of removal of slime from the bay. Rather it suggested that the plugging was the result of microbial colonization and growth within the matrix of the filter. The large surface area of the filter matrix provides ideal conditions for biofilm growth and the flow of water provides a ready supply of nutrients. Based on a careful review of the chemistry specifications and requirements for the fuel bay water it was suggested that the filters, as currently used, were unnecessary and could be either removed or valved out, thereby eliminating the high costs associated with their operation and

  1. 33 CFR 334.860 - San Diego Bay, Calif., Naval Amphibious Base; restricted area.

    Science.gov (United States)

    2010-07-01

    ... Amphibious Base; restricted area. 334.860 Section 334.860 Navigation and Navigable Waters CORPS OF ENGINEERS... Bay, Calif., Naval Amphibious Base; restricted area. (a) The Area. The water of the Pacific Ocean in Middle San Diego Bay in an area extending from the northern and eastern boundary of the Naval Amphibious...

  2. 33 CFR 162.15 - Manhasset Bay, N.Y.; seaplane restricted area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Manhasset Bay, N.Y.; seaplane... Bay, N.Y.; seaplane restricted area. (a) The restricted area. An area in Manhasset Bay between the... line bearing 166°50′ true from latitude 40°50′17.337 N, longitude 73°43′03.877 W, which point is on the...

  3. The Validity Chlorophyll-a Estimation by Sun Induced Fluorescence in Estuarine Waters: An Analysis of Long-term (2003-2011) Water Quality Data from Tampa Bay, Florida (USA)

    Science.gov (United States)

    Moreno-Madrinan, Max Jacobo; Fischer, Andrew

    2012-01-01

    Satellite observation of phytoplankton concentration or chlorophyll-a is an important characteristic, critically integral to monitoring coastal water quality. However, the optical properties of estuarine and coastal waters are highly variable and complex and pose a great challenge for accurate analysis. Constituents such as suspended solids and dissolved organic matter and the overlapping and uncorrelated absorptions in the blue region of the spectrum renders the blue-green ratio algorithms for estimating chlorophyll-a inaccurate. Measurement of sun-induced chlorophyll fluorescence, on the other hand, which utilizes the near infrared portion of the electromagnetic spectrum, may provide a better estimate of phytoplankton concentrations. While modelling and laboratory studies have illustrated both the utility and limitations of satellite baseline algorithms based on the sun induced chlorophyll fluorescence signal, few have examined the empirical validity of these algorithms using a comprehensive long term in situ data set. In an unprecedented analysis of a long term (2003-2011) in situ monitoring data from Tampa Bay, Florida (USA), we assess the validity of the FLH product from the Moderate Resolution Imaging Spectrometer (MODIS) against chlorophyll ]a and a suite of water quality parameters taken in a variety of conditions throughout a large optically complex estuarine system. A systematic analysis of sampling sites throughout the bay is undertaken to understand how the relationship between FLH and in situ chlorophyll-a responds to varying conditions within the estuary including water depth, distance from shore and structures and eight water quality parameters. From the 39 station for which data was derived, 22 stations showed significant correlations when the FLH product was matched with in situ chlorophyll-alpha data. The correlations (r2) for individual stations within Tampa Bay ranged between 0.67 (n=28, pless than 0.01) and-0.457 (n=12, p=.016), indicating that

  4. Spatial variation of phytoplankton community structure in Daya Bay, China.

    Science.gov (United States)

    Jiang, Zhao-Yu; Wang, You-Shao; Cheng, Hao; Zhang, Jian-Dong; Fei, Jiao

    2015-10-01

    Daya Bay is one of the largest and most important gulfs in the southern coast of China, in the northern part of the South China Sea. The phylogenetic diversity and spatial distribution of phytoplankton from the Daya Bay surface water and the relationship with the in situ water environment were investigated by the clone library of the large subunit of ribulose-1, 5-bisphosphate carboxylase (rbcL) gene. The dominant species of phytoplankton were diatoms and eustigmatophytes, which accounted for 81.9 % of all the clones of the rbcL genes. Prymnesiophytes were widely spread and wide varieties lived in Daya Bay, whereas the quantity was limited. The community structure of phytoplankton was shaped by pH and salinity and the concentration of silicate, phosphorus and nitrite. The phytoplankton biomass was significantly positively affected by phosphorus and nitrite but negatively by salinity and pH. Therefore, the phytoplankton distribution and biomass from Daya Bay were doubly affected by anthropic activities and natural factors.

  5. DIFFUSIVE EXCHANGE OF GASEOUS POLYCYCLIC AROMATIC HYDROCARBONS AND POLYCHLORINATED BIPHENYLS ACROSS THE AIR-WATER INTERFACE OF THE CHESAPEAKE BAY. (R825245)

    Science.gov (United States)

    Dissolved and gas-phase concentrations of nine polycyclic aromatic hydrocarbons and 46 polychlorinated biphenyl congeners were measured at eight sites on the Chesapeake Bay at four different times of the year to estimate net diffusive air-water gas exchange rates. Gaseous PAHs ar...

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  7. Bioavailability of heavy metals in water and sediments from a typical Mediterranean Bay (Málaga Bay, Region of Andalucía, Southern Spain).

    Science.gov (United States)

    Alonso Castillo, M L; Sánchez Trujillo, I; Vereda Alonso, E; García de Torres, A; Cano Pavón, J M

    2013-11-15

    Concentrations of heavy metals were measured in sediment and water from Málaga Bay (South Spain). In the later twentieth century, cities such as Málaga, have suffered the impact of mass summer tourism. The ancient industrial activities, and the actual urbanization and coastal development, recreation and tourism, wastewaters treatment facilities, have been sources of marine pollution. In sediments, Ni was the most disturbing metal because Ni concentrations exceeded the effects range low (ERL), concentration at which toxicity could start to be observed in 85% of the samples analyzed. The metal bioavailability decreased in the order: Cd>Ni>Pb>Cu>Cr. In the sea water samples, Cd and Pb were the most disturbing metals because they exceeded the continuous criteria concentration (CCC) of US EPA in a 22.5% and 10.0% of the samples, respectively. Statistical analyses (ANOVA, PCA, CA) were performed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. 77 FR 60302 - Special Local Regulations; Red Bull Flugtag Miami, Biscayne Bay; Miami, FL

    Science.gov (United States)

    2012-10-03

    ... received without jeopardizing the safety or security of people, places or vessels. 7. Unfunded Mandates... waters of Biscayne Bay, Miami, FL between Bayfront Park and the Intercontinental-Miami Hotel encompassed... Area. All waters of Biscayne Bay, Miami, FL between Bayfront Park and the Intercontinental-Miami Hotel...

  9. Multivariate Analysis of Water Quality and Benthic Macrophyte Communities in Florida Bay, USA Reveals Hurricane Effects and Susceptibility to Seagrass Die-Off

    Directory of Open Access Journals (Sweden)

    Amanda M. Cole

    2018-05-01

    Full Text Available Seagrass communities, dominated by Thalassia testudinum, form the principal benthic ecosystem within Florida Bay, Florida USA. The bay has had several large-scale seagrass die-offs in recent decades associated with drought and hypersaline conditions. In addition, three category-5 hurricanes passed in close proximity to the bay during the fall of 2005. This study investigated temporal and spatial trends in macrophyte abundance and water quality from 2006 to 2013 at 15 permanent transect sites, which were co-located with long-term water quality stations. Relationships, by year and by transect location (basin, between antecedent water quality (mean, minimum and maximum for a 6-month period and benthic macrophyte communities were examined using multivariate analyses. Total phosphorus, salinity, pH, turbidity, dissolved inorganic nitrogen (DIN, DIN to phosphate ratio (DIN:PO4-3, chlorophyll a, and dissolved oxygen correlated with temporal and spatial variations in the macrophyte communities. Temporal analysis (MDS and LINKTREE indicated that the fall 2005 hurricanes affected both water quality and macrophyte communities for approximately a 2-year period. Spatial analysis revealed that five basins, which subsequently exhibited a major seagrass die-off during summer 2015, significantly differed from the other ten basins in macrophyte community structure and water quality more than 2 years before this die-off event. High total phosphorus, high pH, low DIN, and low DIN:PO4-3, in combination with deep sediments and high seagrass cover were characteristic of sites that subsequently exhibited severe die-off. Our results indicate basins with more mixed seagrass communities and higher macroalgae abundance are less susceptible to die-off, which is consistent with the management goals of promoting more heterogeneous benthic macrophyte communities.

  10. Theories of transporting processes of Cu in Jiaozhou Bay

    Science.gov (United States)

    Yang, Dongfang; Su, Chunhua; Zhu, Sixi; Wu, Yunjie; Zhou, Wei

    2018-02-01

    Many marine bays have been polluted along with the rapid development of industry and population size, and understanding the transporting progresses of pollutants is essential to pollution control. In order to better understanding the transporting progresses of pollutants in marine, this paper carried on a comprehensive research of the theories of transporting processes of Cu in Jiaozhou Bay. Results showed that the transporting processes of Cu in this bay could be summarized into seven key theories including homogeneous theory, environmental dynamic theory, horizontal loss theory, source to waters transporting theory, sedimentation transporting theory, migration trend theory and vertical transporting theory, respectively. These theories helpful to better understand the migration progress of pollutants in marine bay.

  11. Phytoplankton growth, dissipation, and succession in estuarine environments. [Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Seliger, H H

    1976-01-01

    Two major advances in a study of phytoplankton ecology in the Chesapeake Bay are reported. The annual subsurface transport of a dinoflagellate species (Prorocentrum mariae labouriae) from the mouth of the bay a distance northward of 120 nautical miles to the region of the Bay Bridge was followed. Prorocentrum is a major seasonal dinoflagellate in the Chespeake Bay and annually has been reported to form mahogany tides, dense reddish-brown patches, in the northern bay beginning in late spring and continuing through the summer. Subsequent to this annual appearance the Prorocentrum spread southward and into the western tributary estuaries. The physiological behavioral characteristics of the Prorocentrum were correlated with the physical water movements in the bay. A phytoplankton cage technique for the measurement in situ of the growth rates of natural mixed populations is described. (CH)

  12. Prospecção hidrobiológica da Baía de Sepetiba Color and transparence of waters of Sepetiba Bay, in Rio de Janeiro State

    Directory of Open Access Journals (Sweden)

    Lejeune P. H. de Oliveira

    1971-01-01

    green in the localities with blooms of the diatom Coscinodiscus. The central portion of the bay, 150 Km[squared] hole-green, full of larvae of shrimps Penaeus schmidti; some shoals of shrimps moves its pleopods and by displacement of botton with diatoms and reddish sediment produces a rust color spot in surface of waters seen by fishermen. The estuaries are Isabell color, and caramel. That is a preliminar survey, to future comparison, because to day Sepetiba Bay is not polluted. But futurelly, it will be polluted by an harbour for 3.000,000 tons of iron ore, and by a quay for cargo boats, and siderurgy mills, airports, and other industries. Several polluted waters of Guanabara Bay are black and asphalt color, and cub color. That colors are not found in Sepetiba Bay to day. In 1965, we do not find the "red waters" and "red tides" with blooms of dinoflagellates in Sepetiba Bay, that they are present sometimes in Guanabara Bay with mortalities of fishes. Sepetiba Bay is not biologic problem, to day, is not polluted. The fig. 3 shows a map of transparence of waters by the disc of Secchi and a relation is given of color and transparence, in Sepetiba: Forel color 5: transparence 2.8 m to 2.9 m; Forel n. 6: 2.0 m; Forel color n. 7: 1.0 m to 1.5 m. Moss green waters: 0.6 to 1.5 m; hellebore green waters: 0.9 to 1.5 m; emerald green waters: 2.0 m to 2.2 m; In Guanabara Bay, into the polluted Enseada de Inhaúma: asphalt color waters: 0.02 - 0.05 m; and in black waters: trasnparence of 1 cm. The extintion koeficient of light is indicated in explanation of the fig. 3.

  13. Meteorological and surface water observations from the Chesapeake Bay Interpretive Buoy System from 2007-04-25 to 2016-12-31 (NCEI Accession 0159578)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Meteorological and surface water observations from the Chesapeake Bay Interpretive Buoy System. Ten stations are located from the mouth of the Susquehanna river near...

  14. Cold seeps in Monterey Bay, California: Geochemistry of pore waters and relationship to benthic foraminiferal calcite

    Energy Technology Data Exchange (ETDEWEB)

    Gieskes, Joris, E-mail: jgieskes@ucsd.edu [Scripps Institution of Oceanography, IOD-0208, 9500 Gilman Drive, La Jolla, CA 92093-0208 (United States); Rathburn, Anthony E. [Scripps Institution of Oceanography, IOD-0208, 9500 Gilman Drive, La Jolla, CA 92093-0208 (United States)] [Indiana State University, Department of Earth and Environmental Systems, Terre Haute, IN 47809 (United States); Martin, Jonathan B. [University of Florida, Department of Geological Sciences, Gainesville, FL 32611-2120 (United States); Perez, M. Elena [Indiana State University, Department of Earth and Environmental Systems, Terre Haute, IN 47809 (United States)] [The Natural History Museum, Department of Palaeontology, Cromwell Road, London SW7 5BD (United Kingdom); Mahn, Chris [Scripps Institution of Oceanography, IOD-0208, 9500 Gilman Drive, La Jolla, CA 92093-0208 (United States); Bernhard, Joan M. [Woods Hole Oceanographic Institution, Geology and Geophysics Department, MS52, Woods Hole, MA 02543 (United States); Day, Shelley [University of Florida, Department of Geological Sciences, Gainesville, FL 32611-2120 (United States)

    2011-05-15

    Highlights: > We describe the geochemistry of pore waters in the Clam Flats area of Monterey Bay. > The geochemical data are compared with the {delta}{sup 13}C chemistry of benthic foraminifera. > Living foraminifera indicate little effects of pore water low {delta}{sup 13}C (DIC) in the clam bed. > This phenomenon and its implications are discussed in detail. > Implications with regards to paleo-methane seepage are discussed. - Abstract: An extensive geochemical and biogeochemical examination of CH{sub 4} seeps in the Clam Flats area of Monterey Bay provides insight into the character of relationships between seep geochemistry and benthic foraminiferal geochemistry. The area is characterized by sulfide-rich fluids. Sulfide increases are associated with large increases in alkalinity, as well as small decreases in dissolved Ca and Mg. In addition, only small increases in NH{sub 4} are observed, but values of {delta}{sup 13}C of dissolved inorganic C are as low as -60 per mille at shallow depths (<3 cm). These observations indicate that all these processes are related to the bacterial oxidation of CH{sub 4}, which is transported upward by slow seepage of pore fluids. The geochemistry of the pore fluids should be relevant to the geochemistry of the carbonate tests of living and dead foraminifera. However, a profound disequilibrium of approximately an order of magnitude occurs between the {delta}{sup 13}C values of stained (cytoplasm-containing) foraminiferal carbonate and the C isotope values of ambient pore water dissolved inorganic C. Reasons are unclear for this isotopic disequilibrium, but have important implications for interpretations of foraminiferal carbonate as a paleoenvironmental proxy. Much fine scale work is needed to fully understand the relationships between the biogeochemistry of benthic foraminifera and the geochemistry of the pore waters where they live.

  15. Assessing water quality of the Chesapeake Bay by the impact of sea level rise and warming

    Science.gov (United States)

    Wang, P.; Linker, L.; Wang, H.; Bhatt, G.; Yactayo, G.; Hinson, K.; Tian, R.

    2017-08-01

    The influence of sea level rise and warming on circulation and water quality of the Chesapeake Bay under projected climate conditions in 2050 were estimated by computer simulation. Four estuarine circulation scenarios in the estuary were run using the same watershed load in 1991-2000 period. They are, 1) the Base Scenario, which represents the current climate condition, 2) a Sea Level Rise Scenario, 3) a Warming Scenario, and 4) a combined Sea Level Rise and Warming Scenario. With a 1.6-1.9°C increase in monthly air temperatures in the Warming Scenario, water temperature in the Bay is estimated to increase by 0.8-1°C. Summer average anoxic volume is estimated to increase 1.4 percent compared to the Base Scenario, because of an increase in algal blooms in the spring and summer, promotion of oxygen consumptive processes, and an increase of stratification. However, a 0.5-meter Sea Level Rise Scenario results in a 12 percent reduction of anoxic volume. This is mainly due to increased estuarine circulation that promotes oxygen-rich sea water intrusion in lower layers. The combined Sea Level Rise and Warming Scenario results in a 10.8 percent reduction of anoxic volume. Global warming increases precipitation and consequently increases nutrient loads from the watershed by approximately 5-7 percent. A scenario that used a 10 percent increase in watershed loads and current estuarine circulation patterns yielded a 19 percent increase in summer anoxic volume, while a scenario that used a 10 percent increase in watershed loads and modified estuarine circulation patterns by the aforementioned sea level rise and warming yielded a 6 percent increase in summer anoxic volume. Impacts on phytoplankton, sediments, and water clarity were also analysed.

  16. 33 CFR 110.235 - Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83).

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). 110.235 Section 110.235 Navigation and Navigable Waters COAST... Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). (a) The anchorage grounds—(1...

  17. Responses of water environment to tidal flat reduction in Xiangshan Bay: Part I hydrodynamics

    Science.gov (United States)

    Li, Li; Guan, Weibing; Hu, Jianyu; Cheng, Peng; Wang, Xiao Hua

    2018-06-01

    Xiangshan Bay consists of a deep tidal channel and three shallow inlets. A large-scale tidal flat has been utilized through coastal construction. To ascertain the accumulate influences of these engineering projects upon the tidal dynamics of the channel-inlets system, this study uses FVCOM to investigate the tides and flow asymmetries of the bay, and numerically simulate the long-term variations of tidal dynamics caused by the loss of tidal flats. It was found that the reduction of tidal flat areas from 1963 to 2010 slightly dampened M2 tidal amplitudes (0.1 m, ∼6%) and advanced its phases by reducing shoaling effects, while amplified M4 tidal amplitudes (0.09 m, ∼27%) and advanced its phases by reducing bottom friction, in the inner bay. Consequently, the ebb dominance was dampened indicated by reduced absolute value of elevation skewness (∼20%) in the bay. The tides and tidal asymmetry were impacted by the locations, areas and slopes of the tidal flats through changing tidal prism, shoaling effect and bottom friction, and consequently impacted tidal duration asymmetry in the bay. Tides and tidal asymmetry were more sensitive to the tidal flat at the head of the bay than the side bank. Reduced/increased tidal flat slopes around the Tie inlet dampened the ebb dominance. Tidal flat had a role in dissipating the M4 tide rather than generating it, while the advection only play a secondary role in generating the M4 tide. The full-length tidal flats reclamation would trigger the reverse of ebb to flood dominance in the bay. This study would be applicable for similar narrow bays worldwide.

  18. Environmental consequences of the flooding of the Bay Park Sewage Treatment Plant during Superstorm Sandy.

    Science.gov (United States)

    Swanson, R Lawrence; Wilson, Robert; Brownawell, Bruce; Willig, Kaitlin

    2017-08-15

    Failure of the Bay Park Sewage Treatment Plant (STP) during Superstorm Sandy led to adverse effects in the waters of Hempstead Bay, Long Island, NY. These appear to be related to large discharges of partially treated sewage through its primary and auxiliary outfalls. Modeled dilution discharges indicate that sewage infiltrated the bay, remaining up to 10days. Water column impacts included salinity and dissolved oxygen declines, and biological oxygen demand and nitrogen concentration increases. While the STP does not appear to have released fecal coliform, there were elevated levels of enterococci within the bay for a considerable period following the storm, probably from multiple sources. The STP's reduced functioning and associated environmental impacts, even with resilience upgrades, are not conducive to removing the bay from the list of Impaired Water Bodies. The results reinforce the need to transfer the discharge from the existing outfall to the ocean. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A Review of Use of GIS for the Evaluation of Heavy Metal and Water Quality Parameters in the Canal do Cunha Watershed and west of the Guanabara Bay, Rio de Janeiro (Brazil

    Directory of Open Access Journals (Sweden)

    Renata Coura Borges

    2016-06-01

    Full Text Available As well as other sub-basins of the Guanabara Bay, the Canal do Cunha watershed, located in the Rio de Janeiro city, has suffered severe environmental degradation since the 50s, due to accelerated urban-industrial development. The fluvial dynamics has changed by the deforestation, landfill constructions, drainage and vale occupation. Canal do Cunha deliver wastewaters and sediments at the western side of Guanabara Bay. Contribute to the environmental degradation and has direct influence on the water quality indexes and heavy metal contamination at the western side of Guanabara Bay. This study intends to evaluate, through geoprocessing techniques, the spatial distribution of Lead (Pb, Zinc (Zn, dissolved oxygen (DO and total phosphorus (total P concentrations and pH values, using data provided by six monitoring stations of the Instituto Estadual do Ambiente – INEA (State Environmental Institute. This work allows to observe the influence of weather conditions on Pb and Zn concentrations in superficial waters and surface sediments and the behavior of DO, pH and total P of superficial waters before and after the implementation of the remediation program: Programa de Despoluição da Baía de Guanabara (PDBG; Pollution Remediation Program of Guanabara Bay. Canal do Cunha flow has direct influence on the low quality indexes of water and contributes to the heavy metal contamination and environmental degradation of the western region of Guanabara Bay.

  20. 77 FR 28253 - Safety Zone; America's Cup World Series, East Passage, Narragansett Bay, RI

    Science.gov (United States)

    2012-05-14

    ...-AA00 Safety Zone; America's Cup World Series, East Passage, Narragansett Bay, RI AGENCY: Coast Guard... navigable waters of the East Passage, Narragansett Bay, Rhode Island, during the America's Cup World Series... rulemaking (NPRM) entitled ``Safety Zones; America's Cup World Series, East Passage, Narragansett Bay, RI...

  1. Defining a data management strategy for USGS Chesapeake Bay studies

    Science.gov (United States)

    Ladino, Cassandra

    2013-01-01

    The mission of U.S. Geological Survey’s (USGS) Chesapeake Bay studies is to provide integrated science for improved understanding and management of the Chesapeake Bay ecosystem. Collective USGS efforts in the Chesapeake Bay watershed began in the 1980s, and by the mid-1990s the USGS adopted the watershed as one of its national place-based study areas. Great focus and effort by the USGS have been directed toward Chesapeake Bay studies for almost three decades. The USGS plays a key role in using “ecosystem-based adaptive management, which will provide science to improve the efficiency and accountability of Chesapeake Bay Program activities” (Phillips, 2011). Each year USGS Chesapeake Bay studies produce published research, monitoring data, and models addressing aspects of bay restoration such as, but not limited to, fish health, water quality, land-cover change, and habitat loss. The USGS is responsible for collaborating and sharing this information with other Federal agencies and partners as described under the President’s Executive Order 13508—Strategy for Protecting and Restoring the Chesapeake Bay Watershed signed by President Obama in 2009. Historically, the USGS Chesapeake Bay studies have relied on national USGS databases to store only major nationally available sources of data such as streamflow and water-quality data collected through local monitoring programs and projects, leaving a multitude of other important project data out of the data management process. This practice has led to inefficient methods of finding Chesapeake Bay studies data and underutilization of data resources. Data management by definition is “the business functions that develop and execute plans, policies, practices and projects that acquire, control, protect, deliver and enhance the value of data and information.” (Mosley, 2008a). In other words, data management is a way to preserve, integrate, and share data to address the needs of the Chesapeake Bay studies to better

  2. 33 CFR 334.761 - Naval Support Activity Panama City; St. Andrews Bay; restricted areas.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Naval Support Activity Panama City; St. Andrews Bay; restricted areas. 334.761 Section 334.761 Navigation and Navigable Waters CORPS... REGULATIONS § 334.761 Naval Support Activity Panama City; St. Andrews Bay; restricted areas. (a) The areas—(1...

  3. Sepetiba Bay: an integrated study of an harbour location

    International Nuclear Information System (INIS)

    Bandeira, J.V.; Aun, P.E.; Castro, J.O.N.M. de; Moreira, R.M.

    1984-01-01

    Several aspects of the construction of an iron-ore and coal terminal in Sepetiba bay (RJ, Brazil) in the region of south of Madeira Island, are presented. The studies include a general view of the geomorphology of the region, analyses of current measurements, water circulation and sedimentology of the bay by conventional methods and by radioactive tracers. (M.A.C.) [pt

  4. Water Use Efficiency Improvement against a Backdrop of Expanding City Agglomeration in Developing Countries—A Case Study on Industrial and Agricultural Water Use in the Bohai Bay Region of China

    Directory of Open Access Journals (Sweden)

    Minghao Bai

    2017-02-01

    Full Text Available Most city agglomerations of developing countries face water shortages and pollution due to population growth and industrial aggregation. To meet such water security challenges, policy makers need to evaluate water use efficiency at the regional or basin level because the prosperity of city agglomerations is indispensable to the sustainable development of the region or basin. To solve the issue, this paper adopts a non-directional distance function within the framework of environmental production technology to measure water use efficiency. Based on the distance between actual water use efficiency and the ideal efficiency, it calculates the potential reduction space of water input and pollutants by slack adjustment. Added to the Malmquist index, it forms a non-radial Malmquist water use performance index, which can be divided into technological change and technical efficiency change, to measure dynamic water use efficiency. Further, water use efficiency change is analyzed from the perspectives of technological improvement and institutional construction. Bohai Bay city agglomeration, a typical water-deficient city agglomeration in China, is taken as a case study, and data on water resource, environment, and economy from 2011 to 2014 have been used. In conclusion, there is much space for water use efficiency improvement on the whole. However, even having considered potential reduction space of water input and pollutant discharge under current environmental production technology, it is still not enough to support the city agglomeration’s sustainable development. To relieve current potential water safety hazards, not only technical improvement but also institution innovation for highly efficient water use should be kept accelerating in Bohai Bay region. In terms of urban water management in developing countries, the research conclusion is of theoretical and practical significance.

  5. Retrospective Review of Watershed Characteristics and a Framework for Future Research in the Sarasota Bay Watershed, Florida

    Science.gov (United States)

    Kish, George R.; Harrison, Arnell S.; Alderson, Mark

    2008-01-01

    The U.S. Geological Survey, in cooperation with the Sarasota Bay Estuary Program conducted a retrospective review of characteristics of the Sarasota Bay watershed in west-central Florida. This report describes watershed characteristics, surface- and ground-water processes, and the environmental setting of the Sarasota Bay watershed. Population growth during the last 50 years is transforming the Sarasota Bay watershed from rural and agriculture to urban and suburban. The transition has resulted in land-use changes that influence surface- and ground-water processes in the watershed. Increased impervious cover decreases recharge to ground water and increases overland runoff and the pollutants carried in the runoff. Soil compaction resulting from agriculture, construction, and recreation activities also decreases recharge to ground water. Conventional approaches to stormwater runoff have involved conveyances and large storage areas. Low-impact development approaches, designed to provide recharge near the precipitation point-of-contact, are being used increasingly in the watershed. Simple pollutant loading models applied to the Sarasota Bay watershed have focused on large-scale processes and pollutant loads determined from empirical values and mean event concentrations. Complex watershed models and more intensive data-collection programs can provide the level of information needed to quantify (1) the effects of lot-scale land practices on runoff, storage, and ground-water recharge, (2) dry and wet season flux of nutrients through atmospheric deposition, (3) changes in partitioning of water and contaminants as urbanization alters predevelopment rainfall-runoff relations, and (4) linkages between watershed models and lot-scale models to evaluate the effect of small-scale changes over the entire Sarasota Bay watershed. As urbanization in the Sarasota Bay watershed continues, focused research on water-resources issues can provide information needed by water

  6. Potential risk to wood storks (Mycteria americana) from mercury in Carolina Bay fish

    International Nuclear Information System (INIS)

    Brant, H.A.; Jagoe, C.H.; Snodgrass, J.W.; Bryan, A.L.; Gariboldi, J.C.

    2002-01-01

    Fish mercury levels from some Carolina bays pose risk to wood stork. - Carolina bays are freshwater wetlands that serve as important feeding habitats for the endangered wood stork (Mycteria americana). Water levels in these bays fluctuate greatly and tend to be acidic and rich in dissolved organic carbon (DOC), factors that favor mercury (Hg) methylation and bioaccumulation in fish. To assess potential risks to wood storks consuming mercury contaminated fish in bays, we sampled fish from 10 bays on the Savannah River Site (SRS), South Carolina, an area with documented use by wood storks. Whole body mercury concentrations in 258 fishes of three species (Erimyzon sucetta, Acantharchus pomotis and Esox americanus) commonly consumed by wood storks were determined. Risk factors for nestlings and free-ranging adults were calculated using published no and lowest observable adverse effect concentration (NOAEC and LOAEC) values for birds. Fish from higher trophic levels and those from wetlands with relatively shallow maximum depths and fluctuating water levels were more likely to exceed NOAEC and LOAEC values. Calculation of exposure rates of nestling wood storks indicated they are at highest risk during the first 10 days of the nestling period. These calculations suggest that there is potential concern for wood storks foraging in relatively shallow bays with fluctuating water levels, even though there is no obvious local source of mercury to these wetlands

  7. Development of wavelet-ANN models to predict water quality parameters in Hilo Bay, Pacific Ocean.

    Science.gov (United States)

    Alizadeh, Mohamad Javad; Kavianpour, Mohamad Reza

    2015-09-15

    The main objective of this study is to apply artificial neural network (ANN) and wavelet-neural network (WNN) models for predicting a variety of ocean water quality parameters. In this regard, several water quality parameters in Hilo Bay, Pacific Ocean, are taken under consideration. Different combinations of water quality parameters are applied as input variables to predict daily values of salinity, temperature and DO as well as hourly values of DO. The results demonstrate that the WNN models are superior to the ANN models. Also, the hourly models developed for DO prediction outperform the daily models of DO. For the daily models, the most accurate model has R equal to 0.96, while for the hourly model it reaches up to 0.98. Overall, the results show the ability of the model to monitor the ocean parameters, in condition with missing data, or when regular measurement and monitoring are impossible. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. THE INFLUENCE OF COASTAL CONDITIONS TO TSUNAMI INUNDATION OF BIMA BAY, WEST NUSA TENGGARA

    Directory of Open Access Journals (Sweden)

    Yudhicara Yudhicara

    2017-07-01

    Full Text Available Area along the coast that includes the territorial waters of the Bima Bay, West Nusa Tenggara, is prone to tsunamis, evidenced by the historical tsunamis record in 1815 due to the volcanic eruption of Tambora, 1818, 1836 and 1992 caused by earthquakes associated with tectonic system in the north of the island of Sumbawa, and 1892 were sourced from a distant source. Based on the coastal characteristics, the research area was divided into four types of beaches, namely: Steep rocky beach; Coastal walled plain; Flat coastal mangroves; and Flat sandy beaches. According to the lateral measurement, houses were built in the plains with a minimum height difference of 0.04 m at Rababuntu beach and a maximum of 22.63 m in New Asakota area. The settlement closest distance to the coastline is 10.3 m in Rababuntu, while the farthest extent is at Kawananta 194.58 m from the shoreline. The local bathymetry range between 1 and 42.5 m, where the inside of the very shallow waters of the Bay of Bima, gradually steeper at the mouth of the bay to the open sea. This conditions will influence the wave when entering the bay. It will come with large enough speed at the mouth of the bay, spread along the coastal waters of the eastern and continue spreading to all parts with the diminishing velocity, but the height increasing when it reaches shallow water, especially in the waters of the western Gulf of Bima. Several factors can affect the amount of risk that would be caused by the tsunami, in the research area include are: (1 The research area is located in an enclosed bay; (2 The local sea floor depths around the bay is relatively shallow waters; (3 Coastal characteristics of the research area is dominated by a gently sloping beach morphology with low relief, especially in the area of ??Bajo, Rababuntu and Bontokape and other beaches in the city of Bima; (4 Residential location very close to the shoreline; (5 Minimal vegetation cover; and (6 The presence of the

  9. Baseline surveys of Lac Bay benthic and fish communities, Bonaire

    NARCIS (Netherlands)

    Debrot, A.O.; Hylkema, A.; Vogelaar, W.; Meesters, H.W.G.; Engel, M.S.; Leon, R.; Prud'homme van Reine, W.F.; Nagelkerken, I.

    2012-01-01

    Lac Bay is a clear-water, 5 m deep shallow tropical lagoon of 7 km2 opening onto the wave and wind exposed east coast of the island of Bonaire, southern Caribbean. Over the last decades land reclamation by mangroves in Lac has been expanding the surface of turbid, saline backwaters into the bay at

  10. Environmental and Sanitary Conditions of Guanabara Bay, Rio de Janeiro

    Science.gov (United States)

    Fistarol, Giovana O.; Coutinho, Felipe H.; Moreira, Ana Paula B.; Venas, Tainá; Cánovas, Alba; de Paula, Sérgio E. M.; Coutinho, Ricardo; de Moura, Rodrigo L.; Valentin, Jean Louis; Tenenbaum, Denise R.; Paranhos, Rodolfo; do Valle, Rogério de A. B.; Vicente, Ana Carolina P.; Amado Filho, Gilberto M.; Pereira, Renato Crespo; Kruger, Ricardo; Rezende, Carlos E.; Thompson, Cristiane C.; Salomon, Paulo S.; Thompson, Fabiano L.

    2015-01-01

    Guanabara Bay is the second largest bay in the coast of Brazil, with an area of 384 km2. In its surroundings live circa 16 million inhabitants, out of which 6 million live in Rio de Janeiro city, one of the largest cities of the country, and the host of the 2016 Olympic Games. Anthropogenic interference in Guanabara Bay area started early in the XVI century, but environmental impacts escalated from 1930, when this region underwent an industrialization process. Herein we present an overview of the current environmental and sanitary conditions of Guanabara Bay, a consequence of all these decades of impacts. We will focus on microbial communities, how they may affect higher trophic levels of the aquatic community and also human health. The anthropogenic impacts in the bay are flagged by heavy eutrophication and by the emergence of pathogenic microorganisms that are either carried by domestic and/or hospital waste (e.g., virus, KPC-producing bacteria, and fecal coliforms), or that proliferate in such conditions (e.g., vibrios). Antibiotic resistance genes are commonly found in metagenomes of Guanabara Bay planktonic microorganisms. Furthermore, eutrophication results in recurrent algal blooms, with signs of a shift toward flagellated, mixotrophic groups, including several potentially harmful species. A recent large-scale fish kill episode, and a long trend decrease in fish stocks also reflects the bay’s degraded water quality. Although pollution of Guanabara Bay is not a recent problem, the hosting of the 2016 Olympic Games propelled the government to launch a series of plans to restore the bay’s water quality. If all plans are fully implemented, the restoration of Guanabara Bay and its shores may be one of the best legacies of the Olympic Games in Rio de Janeiro. PMID:26635734

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

    International Nuclear Information System (INIS)

    Honda, Teruyuki; Kimura, Ken-ichiro

    2003-01-01

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

  12. Management case study: Tampa Bay, Florida

    Science.gov (United States)

    Morrison, G.; Greening, H.S.; Yates, K.K.

    2012-01-01

    Tampa Bay, Florida,USA, is a shallow,subtropical estuary that experienced severe cultural eutrophication between the 1940s and 1980s, a period when the human population of its watershed quadrupled. In response, citizen action led to the formation of a public- and private-sector partnership (the Tampa Bay Estuary Program), which adopted a number of management objectives to support the restoration and protection of the bay’s living resources. These included numeric chlorophyll a and water-clarity targets, as well as long-term goals addressing the spatial extent of sea grasses and other selected habitat types, to support estuarine-dependent faunal guilds.

  13. Influence of marine current on vertical migration of Pb in marine bay

    Science.gov (United States)

    Yu, Chen; Hong, Ai; Danfeng, Yang; Huijuan, Zhao; Dongfang, Yang

    2018-02-01

    This paper analyzed that vertical migration of Pb contents waters in Jiaozhou Bay, and revealed the influence of marine current on vertical migration process. Results showed that Pb contents in bottom waters of Jiaozhou Bay in April and July 1988 were 1.49-18.53 μg L-1 and 12.68/-27.64 μg L-1, respectively. The pollution level of Pb in bottom waters was moderate to heavy, and were showing temporal variations and spatial heterogeneity. The vertical migration process of Pb in April 1988 included a drifting process from the southwest to the north by means of the marine current was rapid in this region. The vertical migration process of Pb in July 1988 in the open waters included no drifting process since the flow rate of marine current was relative low in this region. The vertical migration process of Pb was jointly determined by vertical water’s effect, source input and water exchange, and the influence of marine current on the vertical migration of Pb in marine bay was significant.

  14. U.S. Geological Survey Science—Improving the value of the Chesapeake Bay watershed

    Science.gov (United States)

    Phillips, Scott W.; Hyer, Kenneth; Goldbaum, Elizabeth

    2017-05-05

    IntroductionCongress directed the Federal Government to work with States to restore the Nation’s largest estuary.Chesapeake Bay restoration provides important economic and ecological benefits:18 million people live and work in the Bay watershed and enjoy its benefits.3,600 types of fish, wildlife, and plants underpin the economic value of the Bay ecosystem.Poor water quality and habitat loss threaten restoration and negatively impact the economy.10 Goals to meet by 2025 through the Chesapeake Bay Program, a voluntary partnership.

  15. Variation of phytoplankton biomass and primary production in Daya Bay during spring and summer

    International Nuclear Information System (INIS)

    Song Xingyu; Huang Liangmin; Zhang Jianlin; Huang, Xiaoping; Zhang Junbin; Yin Jianqiang; Tan Yehui; Liu Sheng

    2004-01-01

    Environmental factors, phytoplankton biomass (Chl a) and primary production of two water areas in Daya Bay (Dapeng'ao Bay and Aotou Bay) were investigated during the transition period from spring to summer. Chl a ranged from 3.20 to 13.62 and 13.43 to 26.49 mg m -3 in Dapeng'ao Bay and Aotou Bay respectively, if data obtained during red tides are excluded. Primary production varied between 239.7 and 1001.4 mgC m -2 d -1 in Dapeng'ao Bay. The regional distribution of Chl a and primary production were mostly consistent from spring to summer in both bays. Seasonal transition characters have been found in Daya Bay from spring to summer, including high values of DO, nitrate and silicate. Size structures of phytoplankton and its primary production do not change very much from spring to summer, with micro-phytoplankton dominating and contributing about 50% of the whole. In Daya Bay, phytoplankton is limited by nitrogen in spring, and by phosphate in summer. Artificial impacts are evident from high temperature effluent from nuclear power stations, aquaculture and sewage. During the investigation, a red tide occurred in Aotou Bay, with a maximum Chl a of 103.23 mg m -3 at surface and primary production of 2721.9 mgC m -2 d -1 in the red tide center. Raised water temperature and nutrient supply from land-sources help to stimulate annual red tides

  16. Management case study: Tampa Bay, Florida

    Science.gov (United States)

    Morrison, Gerold; Greening, Holly; Yates, Kimberly K.; Wolanski, Eric; McLusky, Donald S.

    2011-01-01

    Tampa Bay, Florida, USA, is a shallow, subtropical estuary that experienced severe cultural eutrophication between the 1940s and 1980s, a period when the human population of its watershed quadrupled. In response, citizen action led to the formation of a public- and private-sector partnership (the Tampa Bay Estuary Program), which adopted a number of management objectives to support the restoration and protection of the bay’s living resources. These included numeric chlorophyll a and water-clarity targets, as well as long-term goals addressing the spatial extent of seagrasses and other selected habitat types, to support estuarine-dependent faunal guilds. Over the past three decades, nitrogen controls involving sources such as wastewater treatment plants, stormwater conveyance systems, fertilizer manufacturing and shipping operations, and power plants have been undertaken to meet these and other management objectives. Cumulatively, these controls have resulted in a 60% reduction in annual total nitrogen (TN) loads relative to earlier worse-case (latter 1970s) conditions. As a result, annual water-clarity and chlorophyll a targets are currently met in most years, and seagrass cover measured in 2008 was the highest recorded since 1950. Factors that have contributed to the observed improvements in Tampa Bay over the past several decades include the following: (1) Development of numeric, science-based water-quality targets to meet a long-term goal of restoring seagrass acreage to 1950s levels. Empirical and mechanistic models found that annual average chlorophyll a concentrations were a primary manageable factor affecting light attenuation. The models also quantified relationships between TN loads, chlorophyll a concentrations, light attenuation, and fluctuations in seagrass cover. The availability of long-term monitoring data, and a systematic process for using the data to evaluate the effectiveness of management actions, has allowed managers to track progress and

  17. Mapping Oyster Reef Habitats in Mobile Bay

    Science.gov (United States)

    Bolte, Danielle

    2011-01-01

    Oyster reefs around the world are declining rapidly, and although they haven t received as much attention as coral reefs, they are just as important to their local ecosystems and economies. Oyster reefs provide habitats for many species of fish, invertebrates, and crustaceans, as well as the next generations of oysters. Oysters are also harvested from many of these reefs and are an important segment of many local economies, including that of Mobile Bay, where oysters rank in the top five commercial marine species both by landed weight and by dollar value. Although the remaining Mobile Bay oyster reefs are some of the least degraded in the world, projected climate change could have dramatic effects on the health of these important ecosystems. The viability of oyster reefs depends on water depth and temperature, appropriate pH and salinity levels, and the amount of dissolved oxygen in the water. Projected increases in sea level, changes in precipitation and runoff patterns, and changes in pH resulting from increases in the amount of carbon dioxide dissolved in the oceans could all affect the viability of oyster reefs in the future. Human activities such as dredging and unsustainable harvesting practices are also adversely impacting the oyster reefs. Fortunately, several projects are already under way to help rebuild or support existing or previously existing oyster reefs. The success of these projects will depend on the local effects of climate change on the current and potential habitats and man s ability to recognize and halt unsustainable harvesting practices. As the extent and health of the reefs changes, it will have impacts on the Mobile Bay ecosystem and economy, changing the resources available to the people who live there and to the rest of the country, since Mobile Bay is an important national source of seafood. This project identified potential climate change impacts on the oyster reefs of Mobile Bay, including the possible addition of newly viable

  18. 33 CFR 162.20 - Flushing Bay near La Guardia Airport, Flushing, N.Y.; restricted area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flushing Bay near La Guardia Airport, Flushing, N.Y.; restricted area. 162.20 Section 162.20 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.20 Flushing Bay near La Guardia Airport, Flushing, N.Y.; restricted area. (a...

  19. 33 CFR 334.370 - Chesapeake Bay, Lynnhaven Roads; danger zones, U.S. Naval Amphibious Base.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Chesapeake Bay, Lynnhaven Roads; danger zones, U.S. Naval Amphibious Base. 334.370 Section 334.370 Navigation and Navigable Waters CORPS... REGULATIONS § 334.370 Chesapeake Bay, Lynnhaven Roads; danger zones, U.S. Naval Amphibious Base. (a...

  20. Thermal waters along the Konocti Bay fault zone, Lake County, California: a re-evaluation

    Science.gov (United States)

    Thompson, J.M.; Mariner, R.H.; White, L.D.; Presser, T.S.; Evans, William C.

    1992-01-01

    The Konocti Bay fault zone (KBFZ), initially regarded by some as a promising target for liquid-dominated geothermal systems, has been a disappointment. At least five exploratory wells were drilled in the vicinity of the KBFZ, but none were successful. Although the Na-K-Ca and Na-Li geothermometers indicate that the thermal waters discharging in the vicinity of Howard and Seigler Springs may have equilibrated at temperatures greater than 200??C, the spring temperatures and fluid discharges are low. Most thermal waters along the KBFZ contain >100 mg/l Mg. High concentrations of dissolved magnesium are usually indicative of relatively cool hydrothermal systems. Dissolution of serpentine at shallow depths may contribute dissolved silica and magnesium to rising thermal waters. Most thermal waters are saturated with respect to amorphous silica at the measured spring temperature. Silica geothermometers and mixing models are useless because the dissolved silica concentration is not controlled by the solubility of either quartz or chalcedony. Cation geothermometry indicates the possibility of a high-temperature fluid (> 200??C) only in the vicinity of Howard and Seigler Springs. However, even if the fluid temperature is as high as that indicated by the geothermometers, the permeability may be low. Deuterium and oxygen-18 values of the thermal waters indicate that they recharged locally and became enriched in oxygen-18 by exchange with rock. Diluting meteoric water and the thermal water appear to have the same deuterium value. Lack of tritium in the diluted spring waters suggest that the diluting water is old. ?? 1992.

  1. A field study of littoral processes in Estero Bay, California

    Science.gov (United States)

    Dingler, J.R.; Anima, R.J.; Molzan, D.E.; Luepke, Gretchen; Peterson, C.L.

    1982-01-01

    Estero Bay, which lies on the central California coast, has rocky headlands at both ends and sandy beaches within it. The shoreline of the bay has adjusted to be in equilibrium with the predominant wave climate, which is from the northwest. Because of its present shoreline configuration, the net southward littoral transport found along much of the California coast does not occur within Estero Bay. Instead, the sand primarily moves on- and offshore with a reversing longshore component. This sand transport pattern produces a littoral cell within Estero Bay even though there is no submarine canyon in the area. The primary sand sinks for this cell appear to be the sand spit south of Morro Rock and the entrance to Morro Bay itself, although this opinion was not experimentally verified. Field work during one summer (1978) and the following winter (1979) produced baseline data on the profile of and grain-size distribution across the littoral zone. In the offshore part of the littoral zone we also studied ripple size and type, internal structure, depth of erosion, and mineralogy. Although these data, which were collected along nine transects spaced 2 km apart, are inadequate to yield transport and energy rates, they indicate a northward decrease in wave energy within Estero Bay and a mixing of the sediments in the offshore. Box core and rod height data from grid points in seven meters of water showed that on the order of a meter of erosion occurred in the central part of the bay between the two sampling periods. Offshore, the data were incomplete, but at one station, in 17 m of water, at least 20 cm of erosion occurred.

  2. Field guide to fishes of the chesapeake bay

    CERN Document Server

    Murdy, Edward O.

    2013-01-01

    The only comprehensive field guide to the Chesapeake’s fishes, this book is an indispensable resource for both anglers and students of the Bay. Vivid illustrations by Val Kells complement the expertise of researchers Edward O. Murdy and John A. Musick. They describe fishes that inhabit waters ranging from low-salinity estuaries to the point where the Bay meets the Atlantic Ocean. Key features of this field guide include• full-color illustrations of more than 200 species• text that is presented adjacent to illustrations for easy reference• detailed descriptions of physical characteristics, range, occurrence in the Bay, reproduction, diet, and statistics from fisheries research• spot illustrations that highlight critical features of certain fish• illustrations of juveniles when they look different from adults• appendices that include identification keys Formatted as a compact field guide for students, scientists, researchers, and fishermen, Field Guide to Fishes of the Chesapeake Bay should be a ...

  3. 46 CFR 180.207 - Survival craft-vessels operating on lakes, bays, and sounds routes.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Survival craft-vessels operating on lakes, bays, and... Survival Craft § 180.207 Survival craft—vessels operating on lakes, bays, and sounds routes. (a) Except as... warm water is not required to carry survival craft. (d) A vessel certificated to operate on lakes, bays...

  4. Cosmogenic neutron production at Daya Bay

    Science.gov (United States)

    An, F. P.; Balantekin, A. B.; Band, H. R.; Bishai, M.; Blyth, S.; Cao, D.; Cao, G. F.; Cao, J.; Chan, Y. L.; Chang, J. F.; Chang, Y.; Chen, H. S.; Chen, S. M.; Chen, Y.; Chen, Y. X.; Cheng, J.; Cheng, Z. K.; Cherwinka, J. J.; Chu, M. C.; Chukanov, A.; Cummings, J. P.; Ding, Y. Y.; Diwan, M. V.; Dolgareva, M.; Dove, J.; Dwyer, D. A.; Edwards, W. R.; Gill, R.; Gonchar, M.; Gong, G. H.; Gong, H.; Grassi, M.; Gu, W. Q.; Guo, L.; Guo, X. H.; Guo, Y. H.; Guo, Z.; Hackenburg, R. W.; Hans, S.; He, M.; Heeger, K. M.; Heng, Y. K.; Higuera, A.; Hsiung, Y. B.; Hu, B. Z.; Hu, T.; Huang, H. X.; Huang, X. T.; Huang, Y. B.; Huber, P.; Huo, W.; Hussain, G.; Jaffe, D. E.; Jen, K. L.; Ji, X. L.; Ji, X. P.; Jiao, J. B.; Johnson, R. A.; Jones, D.; Kang, L.; Kettell, S. H.; Khan, A.; Koerner, L. W.; Kohn, S.; Kramer, M.; Kwok, M. W.; Langford, T. J.; Lau, K.; Lebanowski, L.; Lee, J.; Lee, J. H. C.; Lei, R. T.; Leitner, R.; Leung, J. K. C.; Li, C.; Li, D. J.; Li, F.; Li, G. S.; Li, Q. J.; Li, S.; Li, S. C.; Li, W. D.; Li, X. N.; Li, X. Q.; Li, Y. F.; Li, Z. B.; Liang, H.; Lin, C. J.; Lin, G. L.; Lin, S.; Lin, S. K.; Lin, Y.-C.; Ling, J. J.; Link, J. M.; Littenberg, L.; Littlejohn, B. R.; Liu, J. C.; Liu, J. L.; Loh, C. W.; Lu, C.; Lu, H. Q.; Lu, J. S.; Luk, K. B.; Ma, X. B.; Ma, X. Y.; Ma, Y. Q.; Malyshkin, Y.; Martinez Caicedo, D. A.; McDonald, K. T.; McKeown, R. D.; Mitchell, I.; Nakajima, Y.; Napolitano, J.; Naumov, D.; Naumova, E.; Ochoa-Ricoux, J. P.; Olshevskiy, A.; Pan, H.-R.; Park, J.; Patton, S.; Pec, V.; Peng, J. C.; Pinsky, L.; Pun, C. S. J.; Qi, F. Z.; Qi, M.; Qian, X.; Qiu, R. M.; Raper, N.; Ren, J.; Rosero, R.; Roskovec, B.; Ruan, X. C.; Steiner, H.; Sun, J. L.; Tang, W.; Taychenachev, D.; Treskov, K.; Tsang, K. V.; Tse, W.-H.; Tull, C. E.; Viaux, N.; Viren, B.; Vorobel, V.; Wang, C. H.; Wang, M.; Wang, N. Y.; Wang, R. G.; Wang, W.; Wang, X.; Wang, Y. F.; Wang, Z.; Wang, Z.; Wang, Z. M.; Wei, H. Y.; Wen, L. J.; Whisnant, K.; White, C. G.; Wise, T.; Wong, H. L. H.; Wong, S. C. F.; Worcester, E.; Wu, C.-H.; Wu, Q.; Wu, W. J.; Xia, D. M.; Xia, J. K.; Xing, Z. Z.; Xu, J. L.; Xu, Y.; Xue, T.; Yang, C. G.; Yang, H.; Yang, L.; Yang, M. S.; Yang, M. T.; Yang, Y. Z.; Ye, M.; Ye, Z.; Yeh, M.; Young, B. L.; Yu, Z. Y.; Zeng, S.; Zhan, L.; Zhang, C.; Zhang, C. C.; Zhang, H. H.; Zhang, J. W.; Zhang, Q. M.; Zhang, R.; Zhang, X. T.; Zhang, Y. M.; Zhang, Y. M.; Zhang, Y. X.; Zhang, Z. J.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, J.; Zhou, L.; Zhuang, H. L.; Zou, J. H.; Daya Bay Collaboration

    2018-03-01

    Neutrons produced by cosmic ray muons are an important background for underground experiments studying neutrino oscillations, neutrinoless double beta decay, dark matter, and other rare-event signals. A measurement of the neutron yield in the three different experimental halls of the Daya Bay Reactor Neutrino Experiment at varying depth is reported. The neutron yield in Daya Bay's liquid scintillator is measured to be Yn=(10.26 ±0.86 )×10-5 , (10.22 ±0.87 )×10-5 , and (17.03 ±1.22 )×10-5 μ-1 g-1 cm2 at depths of 250, 265, and 860 meters-water-equivalent. These results are compared to other measurements and the simulated neutron yield in Fluka and Geant4. A global fit including the Daya Bay measurements yields a power law coefficient of 0.77 ±0.03 for the dependence of the neutron yield on muon energy.

  5. Toxic phytoplankton in San Francisco Bay

    Science.gov (United States)

    Rodgers, Kristine M.; Garrison, David L.; Cloern, James E.

    1996-01-01

    The Regional Monitoring Program (RMP) was conceived and designed to document the changing distribution and effects of trace substances in San Francisco Bay, with focus on toxic contaminants that have become enriched by human inputs. However, coastal ecosystems like San Francisco Bay also have potential sources of naturally-produced toxic substances that can disrupt food webs and, under extreme circumstances, become threats to public health. The most prevalent source of natural toxins is from blooms of algal species that can synthesize metabolites that are toxic to invertebrates or vertebrates. Although San Francisco Bay is nutrient-rich, it has so far apparently been immune from the epidemic of harmful algal blooms in the world’s nutrient-enriched coastal waters. This absence of acute harmful blooms does not imply that San Francisco Bay has unique features that preclude toxic blooms. No sampling program has been implemented to document the occurrence of toxin-producing algae in San Francisco Bay, so it is difficult to judge the likelihood of such events in the future. This issue is directly relevant to the goals of RMP because harmful species of phytoplankton have the potential to disrupt ecosystem processes that support animal populations, cause severe illness or death in humans, and confound the outcomes of toxicity bioassays such as those included in the RMP. Our purpose here is to utilize existing data on the phytoplankton community of San Francisco Bay to provide a provisional statement about the occurrence, distribution, and potential threats of harmful algae in this Estuary.

  6. Oceanographic characteristics of an impacted coastal bay: Baía de Guanabara, Rio de Janeiro, Brazil

    Science.gov (United States)

    Kjerfve, Björn; Ribeiro, Cesar H. A.; Dias, Gilberto T. M.; Filippo, Alessandro M.; Da Silva Quaresma, Valéria

    1997-11-01

    Baía de Guanabara is a 384 km 2 eutrophic coastal bay in Brazil, impacted by the polluted discharge from the Rio de Janeiro metropolitan area. The structurally controlled bay has a central channel with a depth of 30 m and a sandy bottom near the entrance, reflecting wave and tidal forcing. In contrast, the bay-averaged water depth is 5.7 m and the bottom sediments are mostly muds as a result of the Holocene transgression and rapid fluvial sedimentation, accelerated by channelization of rivers and deforestation. An extensive sand bank is located seaward of the bay entrance and a flood-oriented sand wave system indicates sand transport into the bay. The mean freshwater discharge measures 100±59 m 3 s -1 and is greatest in the rainy austral summer in December and January. Tides are mixed mainly semidiurnal with a range of 0.7 m, and peak spring tidal currents reach 0.5 m s -1 inside the bay and 1.6 m s -1 near the bay entrance. The passage of northward propagating polar fronts results in regular strong southwesterly winds and heavy wave forcing. The bay has mean salinities from 21.0 to 34.5‰ with an average of 29.5±4.8‰. The vertical salinity stratification, Δs/s, varies from 0.06 to 0.21 and is relatively weak and inversely proportional to rms tidal currents. The residual circulation is characterized by both gravitational circulation and transverse residual tidal circulation, measuring 800 and 400 m 3 s -1 respectively. The renewal time of 50% of the bay water volume is 11.4 days. Untreated sewage runoff enters the bay from the west, resulting in locally poor water quality, where the near-bottom mean dissolved oxygen measures only 3.1 mg 1 -1 and results in anoxic bottom muds. The worst water quality is indicated by average fecal coliform of 1140 counts ml -1 and excessive ammonia and phosphate loading. The average chlorophyll concentration in this region responds to the nutrient loading and exceeds 130 μg 1 -1 although 57 μg 1 -1 is the overall mean for

  7. 76 FR 31846 - Safety Zone; 28th Annual Humboldt Bay Festival, Fireworks Display, Eureka, CA

    Science.gov (United States)

    2011-06-02

    ...-AA00 Safety Zone; 28th Annual Humboldt Bay Festival, Fireworks Display, Eureka, CA AGENCY: Coast Guard... support of the 28th Annual Humboldt Bay Festival Fireworks Display on the specified waters off the South... Humboldt Bay Festival Fireworks Display. The fireworks display is for entertainment purposes. This safety...

  8. Hydrochemical and isotopic characteristics of estuarial seawater and river water of Bailanghe in Laizhou Bay, China

    Science.gov (United States)

    Yang, Qiaofeng; Xu, Suning; Wang, Ruijiu; Li, Wenpeng; Wang, Zhiyi; Mei, Junjun; Ding, Zhilei; Yang, Peijie; Yu, Liangju; Lv, Tieying; Bai, Gang; Kang, Wei

    2016-04-01

    In the study of seawater intrusion, seawater is usually taken as an end-member that mixes with other source(s). However, compared to standard seawater, the coastal seawater particularly that near the estuary, can be strongly influenced by the rivers into the sea and by coastal human activities. Their composition can be thus continuously changed and redistributed with space and time. Therefore, before investigating seawater intrusion in a certain area, it is essentially important to determine the features of the estuarine seawater (e.g. the mixture percentage between standard seawater and river water). In this study, we aimed to gain a clear situation of the seawater intrusion in Laizhou Bay, Southern Bohai, China. The issue aforementioned was investigated by comparing the stable isotopic and hydrochemical composition of the marine and river water collected in this area. Samples investigated include 5 surface water samples collected at the downstream of the Bailanghe and 7 seawater samples near the estuary of Laizhou Bay. Inert tracers (δD, δ18O, Cl, Br) and reaction tracers (Na, Mg, SO4, HCO3, Ca, NO3) are particularly analyzed. The major results are as follows: 1) All the river water samples fall below the Global Meteoric Water Line in the δD - δ18O diagram, reflecting evaporation of the upstream reservoir water. The seawater samples fall on the mixing line of standard seawater and the river water in the stable isotopic diagram. 2) The Cl-δ18O diagram indicates widespread dissolution of evaporate into the river, while high concentration of Ca and HCO3-, as well as the SO42- - Cl relation of the river water samples reflect the dissolution of CO2 , carbonate and sulfate in the atmosphere and on the ground. 3) The Br/Cl ratios of seawater samples are closed to the marine ratios. This together with the plots of major ions vs. Cl suggest that the seawater samples are originated from the mixture of standard seawater and river water. Therefore, when referring to the

  9. 75 FR 54771 - Safety Zone; Thunder on the Bay, Chesapeake Bay, Buckroe Beach Park, Hampton, VA

    Science.gov (United States)

    2010-09-09

    ... navigable waters of the Chesapeake Bay within the area bounded by a 210-foot radius circle centered on... are technical standards (e.g., specifications of materials, performance, design, or operation; test... cumulatively have a significant effect on the human environment. This rule is categorically excluded, under...

  10. The outflow of radionuclides from Novaya Zemlya bays. Modeling and monitoring strategies

    International Nuclear Information System (INIS)

    Harms, I.H.; Povinec, P.P.

    1999-01-01

    Hydrodynamic model results are used to evaluate possible monitoring strategies for a continuous survey of underwater dump sites. The Hamburg Shelf Ocean Model (HAMSOM) is applied to Abrosimov Bay and forced with realistic, transient wind fields and air temperatures. The three-dimensional circulation model is coupled to a dynamic-thermodynamic ice model that accounts for surface heat fluxes, fractional ice cover and ice thickness. Model results show significant variations in the bay circulation due to a pronounced seasonality in the wind forcing and the ice cover. The circulation is weakest in early summer when wind speeds are low and the ice still covers most parts of the bay. In autumn, circulation and flushing of the bay is most enhanced, due to increasing wind speeds and the absence of an ice cover. Dispersion scenarios were carried out assuming a leakage at dumped objects. During most of the year the obtained tracer concentrations in the bay are higher in the upper layers than close to the bottom, indicating an outflow at the surface and a compensatory inflow below. This general pattern is only reversed during spring and early summer, when the wind directions change. Since ice problems make it almost impossible to monitor surface waters or even the whole water column in a shallow bay, the only way to install a monitoring system, is at the bottom of the bay, as close as possible to dumped objects. Data transmission via satellite or radio could be realized from a small station located on the bay's edge

  11. The outflow of radionuclides from Novaya Zemlya bays--modeling and monitoring strategies.

    Science.gov (United States)

    Harms, I H; Povinec, P P

    1999-09-30

    Hydrodynamic model results are used to evaluate possible monitoring strategies for a continuous survey of underwater dump sites. The Hamburg Shelf Ocean Model (HAMSOM) is applied to Abrosimov Bay and forced with realistic, transient wind fields and air temperatures. The three-dimensional circulation model is coupled to a dynamic-thermodynamic ice model that accounts for surface heat fluxes, fractional ice cover and ice thickness. Model results show significant variations in the bay circulation due to a pronounced seasonality in the wind forcing and the ice cover. The circulation is weakest in early summer when wind speeds are low and the ice still covers most parts of the bay. In autumn, circulation and flushing of the bay is most enhanced, due to increasing wind speeds and the absence of an ice cover. Dispersion scenarios were carried out assuming a leakage at dumped objects. During most of the year the obtained tracer concentrations in the bay are higher in the upper layers than close to the bottom, indicating an outflow at the surface and a compensatory inflow below. This general pattern is only reversed during spring and early summer, when the wind directions change. Since ice problems make it almost impossible to monitor surface waters or even the whole water column in a shallow bay, the only way to install a monitoring system, is at the bottom of the bay, as close as possible to dumped objects. Data transmission via satellite or radio could be realized from a small station located on the bay's edge.

  12. Seasonal variations and sources of sedimentary organic carbon in Tokyo Bay

    International Nuclear Information System (INIS)

    Kubo, Atsushi; Kanda, Jota

    2017-01-01

    Total organic carbon (TOC), total nitrogen (TN) contents, their stable C and N isotope ratio (δ 13 C and δ 15 N), and chlorophyll a ([Chl a] sed ) of surface sediments were investigated monthly to identify the seasonal variations and sources of organic matter in Tokyo Bay. The sedimentary TOC (TOC sed ) and TN (TN sed ) contents, and the sedimentary δ 13 C and δ 15 N (δ 13 C sed and δ 15 N sed ) values were higher in summer than other seasons. The seasonal variations were controlled by high primary production in the water column and hypoxic water in the bottom water during summer. The fraction of terrestrial and marine derived organic matter was estimated by Bayesian mixing model using stable isotope data and TOC/TN ratio. Surface sediments in Tokyo Bay are dominated by marine derived organic matter, which accounts for about 69 ± 5% of TOC sed . - Highlights: • High values of sedimentary organic carbon and nitrogen were observed in summer. • Surface sediments in Tokyo Bay were dominated by marine derived organic matter which was estimated by Bayesian mixing model. • The most amount of terrestrial POC was deposited and degraded in Tokyo Bay before being discharged to the open ocean.

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

    Directory of Open Access Journals (Sweden)

    Delyuzar Ilahude

    2017-07-01

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

  14. Whole-system metabolism and CO2 fluxes in a Mediterranean Bay dominated by seagrass beds (Palma Bay, NW Mediterranean

    Directory of Open Access Journals (Sweden)

    F. Gazeau

    2005-01-01

    Full Text Available Planktonic and benthic incubations (bare and Posidonia oceanica vegetated sediments were performed at monthly intervals from March 2001 to October 2002 in a seagrass vegetated area of the Bay of Palma (Mallorca, Spain. Results showed a contrast between the planktonic compartment, which was on average near metabolic balance (−4.6±5.9 mmol O2 m-2 d-1 and the benthic compartment, which was autotrophic (17.6±8.5 mmol O2 m-2 d-1. During two cruises in March and June 2002, planktonic and benthic incubations were performed at several stations in the bay to estimate the whole-system metabolism and to examine its relationship with partial pressure of CO2 (pCO2 and apparent oxygen utilisation (AOU spatial patterns. Moreover, during the second cruise, when the residence time of water was long enough, net ecosystem production (NEP estimates based on incubations were compared, over the Posidonia oceanica meadow, to rates derived from dissolved inorganic carbon (DIC and oxygen (O2 mass balance budgets. These budgets provided NEP estimates in fair agreement with those derived from direct metabolic estimates based on incubated samples over the Posidonia oceanica meadow. Whereas the seagrass community was autotrophic, the excess organic carbon production therein could only balance the planktonic heterotrophy in shallow waters relative to the maximum depth of the bay (55 m. This generated a horizontal gradient from autotrophic or balanced communities in the shallow seagrass-covered areas, to strongly heterotrophic communities in deeper areas of the bay. It seems therefore that, on an annual scale in the whole bay, the organic matter production by the Posidonia oceanica may not be sufficient to fully compensate the heterotrophy of the planktonic compartment, which may require external organic carbon inputs, most likely from land.

  15. Humic Substances from Manila Bay and Bolinao Bay Sediments

    Directory of Open Access Journals (Sweden)

    Elma Llaguno

    1997-12-01

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

  16. Numerical investigation of pollution transport and environmental improvement measures in a tidal bay based on a Lagrangian particle-tracking model

    Directory of Open Access Journals (Sweden)

    En-jin Zhao

    2018-01-01

    Full Text Available In view of the severity of oceanic pollution, based on the finite volume coastal ocean model (FVCOM, a Lagrangian particle-tracking model was used to numerically investigate the coastal pollution transport and water exchange capability in Tangdao Bay, in China. The severe pollution in the bay was numerically simulated by releasing and tracking particles inside it. The simulation results demonstrate that the water exchange capability in the bay is very low. Once the bay has suffered pollution, a long period will be required before the environment can purify itself. In order to eliminate or at least reduce the pollution level, environmental improvement measures have been proposed to enhance the seawater exchange capability and speed up the water purification inside the bay. The study findings presented in this paper are believed to be instructive and useful for future environmental policy makers and it is also anticipated that the numerical model in this paper can serve as an effective technological tool to study many emerging coastal environment problems. Keywords: Particle-tracking, Water exchange capability, Lagrangian system, Coastal pollution, Tangdao bay, FVCOM

  17. Hydrodynamic Characteristics and Salinity Patterns in Estero Bay, Lee County, Florida

    Science.gov (United States)

    Byrne, Michael J.; Gabaldon, Jessica N.

    2008-01-01

    Estero Bay is an estuary (about 12 miles long and 3 miles wide) on the southwestern Florida coast, with several inlets connecting the bay to the Gulf of Mexico and numerous freshwater tributaries. Continuous stage and salinity data were recorded at eight gaging stations in Estero Bay estuary from October 2001 to September 2005. Continuous water velocity data were recorded at six of these stations for the purpose of measuring discharge. In addition, turbidity data were recorded at four stations, suspended sediment concentration were measured at three stations, and wind measurements were taken at one station. Salinity surveys, within and around Estero Bay, were conducted 15 times from July 2002 to January 2004. The average daily discharge ranged from 35,000 to -34,000 ft3/s (cubic feet per second) at Big Carlos Pass, 10,800 to -11,200 ft3/s at Matanzas Pass, 2,200 to -2,900 ft3/s at Big Hickory Pass, 680 to -700 ft3/s at Mullock Creek, 330 to -370 ft3/s at Estero River, and 190 to -180 ft3/s at Imperial River. Flood tide is expressed as negative discharge and ebb flow as positive discharge. Reduced salinity at Matanzas Pass was negatively correlated (R2 = 0.48) to freshwater discharge from the Caloosahatchee River at Franklin Locks (S-79). Matanzas Pass is hydrologically linked to Hell Peckney Bay; therefore, water-quality problems associated with the Caloosahatchee River also affect Hell Peckney Bay. Rocky Bay was significantly less saline than Coconut Point and Matanzas Pass was significantly less saline than Ostego Bay, based on data from the salinity surveys. The quality-checked and edited continuous data and the salinity maps have been compiled and are stored on the U.S. Geological Survey South Florida Information Access (SOFIA) website (http://sofia.usgs.gov).

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

    Directory of Open Access Journals (Sweden)

    Khozanah Munawir

    2018-02-01

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

  19. Improvement of FLOWER code and its application in Daya Bay

    International Nuclear Information System (INIS)

    Zhang Shaodong; Zhang Yongxing

    1995-01-01

    FLOWER, a computer code recommended by USNRC for assessing the environmental impact in tidal regions, was adapted and improved so as to be suitable to deal with the influence of drift stream along seashore to the dilution of contaminants and heat in the bay mouth. And the code outputs were presented with more mid-results such as average concentrations and temperature values for all tides considered. Finally, the modified code is applied to the dispersion calculation of heat and liquid effluents from Daya Bay Nuclear Power Plant, and the impacts from routine operation of the plant on Daya Bay sea waters were given

  20. Daya Bay Antineutrino Detector gas system

    Science.gov (United States)

    Band, H. R.; Cherwinka, J. J.; Chu, M.-C.; Heeger, K. M.; Kwok, M. W.; Shih, K.; Wise, T.; Xiao, Q.

    2012-11-01

    The Daya Bay Antineutrino Detector gas system is designed to protect the liquid scintillator targets of the antineutrino detectors against degradation and contamination from exposure to ambient laboratory air. The gas system is also used to monitor the leak tightness of the antineutrino detector assembly. The cover gas system constantly flushes the gas volumes above the liquid scintillator with dry nitrogen to minimize oxidation of the scintillator over the five year lifetime of the experiment. This constant flush also prevents the infiltration of radon or other contaminants into these detecting liquids keeping the internal backgrounds low. Since the Daya Bay antineutrino detectors are immersed in the large water pools of the muon veto system, other gas volumes are needed to protect vital detector cables or gas lines. These volumes are also purged with dry gas. Return gas is monitored for oxygen content and humidity to provide early warning of potentially damaging leaks. The design and performance of the Daya Bay Antineutrino Detector gas system is described.

  1. Benthic flux of nutrients and trace metals in the northern component of San Francisco Bay, California

    Science.gov (United States)

    Kuwabara, James S.; Topping, Brent R.; Parcheso, Francis; Engelstad, Anita C.; Greene, Valerie E.

    2009-01-01

    Two sets of sampling trips were coordinated in late summer 2008 (weeks of July 8 and August 6) to sample the interstitial and overlying bottom waters at 10 shallow locations (9 sites meters in depth) within the northern component of the San Francisco Bay/Delta (herein referred to as North Bay). The work was performed to better understand sources of biologically reactive solutes (namely, dissolved macronutrients and trace metals) that may affect the base of the food web in this part of the estuary. A nonmetallic pore-water profiler was used to obtain the first centimeter-scale estimates of the vertical solute-concentration gradients for diffusive-flux determinations. This study, performed in collaboration with scientists from San Francisco State University?s Romberg Tiburon Center for Environmental Studies, provides information to assist in developing and refining management strategies for the Bay/Delta system and supports efforts to monitor changes in food-web structure associated with regional habitat modifications directed by the California Bay-Delta Authority. On July 7, 2008, and August 5, 2008, pore-water profilers were successfully deployed at six North Bay sites per trip to measure the concentration gradient of dissolved macronutrients and trace metals near the sediment-water interface. Only two of the sites (433 and SSB009 within Honker Bay) were sampled in both series of profiler deployments. At each sampling site, profilers were deployed in triplicate, while discrete samples and dataloggers were used to collect ancillary data from both the water column and benthos to help interpret diffusive-flux measurements. Benthic flux of dissolved (0.2-micron filtered) inorganic phosphate (that is, soluble reactive phosphorus (SRP)) ranged from negligible levels (-0.003?0.005 millimole per square meter per day (mmole m-2d-1) at Site 4.1 outside Honker Bay) to 0.060?0.006 mmole m-2d-1 near the northern coast of Brown?s Island. Except for the elevated flux at Browns

  2. APPLICATION OF GIS AND SATELLITE DATA IN THE INVESTIGATION OF BAYS AND ESTUARIAL ABRASION-ACCUMULATIVE JUMPERS OF THE VOLGOGRAD RESERVOIR

    Directory of Open Access Journals (Sweden)

    M. S. Baranova

    2017-01-01

    Full Text Available The paper presents some results of Volgograd reservoir bays investigation and their abrasion-accumulative jumpers in the estuarial alignments during field expeditionary researching and with the application of geoinformation systems and satellite data. Based on the results of long-term field observations and satellite data, it was founded that most of small and medium-sized bays have natural jumpers of abrasion-accumulative genesis now. The paper contains short characteristics of such bays as Dlinniy Lipoviy, Zharkova, Korotkiy Lipoviy, Bolshoy, Rostoviy, Mostovoy, Drugalka. The authors have created bathymetric maps and graphs of longitudinal profiles for the water areas of some of the bays on the right bank, calculated the areas of estuarial jumpers and the areas of the shallow water zone inside the bays. The bays, characterized in the entry gate by depths from 9 m to 16 m, do not have a predisposition to being overlapped by jumpers, and a number of bays are currently in the stage of separation. In the course of the investigation it was determined that the maximum depth of the break-away bays does not exceed six and half meters; the active process of detachment covers both small and medium-sized bays; among the studied bays considerable areas are occupied by shallow waters with depths of up to 2 meters; geoinformation systems and satellite data allow one to analyze, complete and generalize field research data and receive visual cartographic materials. Based on the results of bathymetric survey, there was revealed a fairly active accumulation of sediments in the abrasion-accumulative forms of the underwater and above-water relief of all the investigated reservoir bays.

  3. Salt balance, fresh water residence time and budget for non ...

    African Journals Online (AJOL)

    Water and salt budgets suggest that in order to balance the inflow and outflow of water at Makoba bay, there is net flux of water from the bay to the open ocean during wet season. Residual salt fluxes between the bay and the open ocean indicate advective salt export. Exchange of water between the bay with the open ocean ...

  4. Some Challenges of an “Upside Down” Nitrogen Budget – Science and Management in Greenwich Bay, RI (USA)

    Science.gov (United States)

    When nutrients impact estuarine water quality, scientists and managers instinctively focus on quantifying and controlling land-based sources. However, in Greenwich Bay, RI, the estuary opens onto a larger and more intensively fertilized coastal water body (Narragansett Bay). Prev...

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

    Science.gov (United States)

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

    2012-12-01

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

  6. ASTER Images San Francisco Bay Area

    Science.gov (United States)

    2000-01-01

    These images of the San Francisco Bay region were acquired on March 3, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. Each covers an area 60 kilometers (37 miles) wide and 75 kilometers (47 miles) long. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image the Earth for the next 6 years to map and monitor the changing surface of our planet.Upper Left: The color infrared composite uses bands in the visible and reflected infrared. Vegetation is red, urban areas are gray; sediment in the bays shows up as lighter shades of blue. Thanks to the 15 meter (50-foot) spatial resolution, shadows of the towers along the Bay Bridge can be seen.Upper right: A composite of bands in the short wave infrared displays differences in soils and rocks in the mountainous areas. Even though these regions appear entirely vegetated in the visible, enough surface shows through openings in the vegetation to allow the ground to be imaged.Lower left: This composite of multispectral thermal bands shows differences in urban materials in varying colors. Separation of materials is due to differences in thermal emission properties, analogous to colors in the visible.Lower right: This is a color coded temperature image of water temperature, derived from the thermal bands. Warm waters are in white and yellow, colder waters are blue. Suisun Bay in the upper right is fed directly from the cold Sacramento River. As the water flows through San Pablo and San Francisco Bays on the way to the Pacific, the waters warm up.Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for

  7. Using the Surface Reflectance MODIS Terra Product to Estimate Turbidity in Tampa Bay, Florida

    Directory of Open Access Journals (Sweden)

    Douglas L. Rickman

    2010-12-01

    Full Text Available Turbidity is a commonly-used index of the factors that determine light penetration in the water column. Consistent estimation of turbidity is crucial to design environmental and restoration management plans, to predict fate of possible pollutants, and to estimate sedimentary fluxes into the ocean. Traditional methods monitoring fixed geographical locations at fixed intervals may not be representative of the mean water turbidity in estuaries between intervals, and can be expensive and time consuming. Although remote sensing offers a good solution to this limitation, it is still not widely used due in part to required complex processing of imagery. There are satellite-derived products, including the Moderate Resolution Imaging Spectroradiometer (MODIS Terra surface reflectance daily product (MOD09GQ Band 1 (620–670 nm which are now routinely available at 250 m spatial resolution and corrected for atmospheric effect. This study shows this product to be useful to estimate turbidity in Tampa Bay, Florida, after rainfall events (R2 = 0.76, n = 34. Within Tampa Bay, Hillsborough Bay (HB and Old Tampa Bay (OTB presented higher turbidity compared to Middle Tampa Bay (MTB and Lower Tampa Bay (LTB.

  8. Sedimentary processes in Boca de Quadra and Smeaton Bay: preliminary evidence from excess 210Pb and interstitial-water chemistry

    International Nuclear Information System (INIS)

    Sugai, S.F.; Burrel, D.C.

    1979-01-01

    Sedimentary profiles of unsupported 210 Pb (t/sub 1/2/ = 22.26 years) coupled with profiles of redox-sensitive metals in the interstitial water suggest sedimentary processes that have occurred in Boca de Quadra and Smeaton Bay within the past several decades. Although average sedimentation rates can be calculated from excess 210 Pb profiles alone, ancillary information is needed to interpret the history recorded in the sedimentary column. Particularly in dynamic environments such as the fjords examined here, it is necessary to examine the combined effects of: (1) rapid deposition of sediment by slumping or major storms; (2) erosional events such as scouring; (3) homogenization of sediment by storm mixing or bioturbation; and (4) deposition of material from a different source. In this report we discuss efforts underway to examine the events responsible for the observed profiles of excess 210 Pb in the sediment of Boca de Quadra and Smeaton Bay

  9. An Intrathermocline Eddy and a tropical cyclone in the Bay of Bengal

    OpenAIRE

    Gordon, Arnold L.; Shroyer, Emily; Murty, V. S. N.

    2017-01-01

    The Bay of Bengal, subjected to monsoonal forcing and tropical cyclones, displays a complex field of ocean eddies. On 5 December 2013 a sub-surface vortex or Intrathermocline Eddy (ITE) composed of water characteristic of the Andaman Sea was observed within the thermocline of the western Bay of Bengal. We propose that the ITE was the product of Tropical Cyclone Lehar interaction on 27 November 2013 with a westward propagating surface eddy from the eastern Bay of Bengal. While Lehar?s interact...

  10. Small-scale variability in peatland pore-water biogeochemistry, Hudson Bay Lowland, Canada.

    Science.gov (United States)

    Ulanowski, T A; Branfireun, B A

    2013-06-01

    The Hudson Bay Lowland (HBL) of northern Ontario, Manitoba and Quebec, Canada is the second largest contiguous peatland complex in the world, currently containing more than half of Canada's soil carbon. Recent concerns about the ecohydrological impacts to these large northern peatlands resulting from climate change and resource extraction have catalyzed a resurgence in scientific research into this ecologically important region. However, the sheer size, heterogeneity and elaborate landscape arrangements of this ecosystem raise important questions concerning representative sampling of environmental media for chemical or physical characterization. To begin to quantify such variability, this study assessed the small-scale spatial (1m) and short temporal (21 day) variability of surface pore-water biogeochemistry (pH, dissolved organic carbon, and major ions) in a Sphagnum spp.-dominated, ombrotrophic raised bog, and a Carex spp.-dominated intermediate fen in the HBL. In general, pore-water pH and concentrations of dissolved solutes were similar to previously reported literature values from this region. However, systematic sampling revealed consistent statistically significant differences in pore-water chemistries between the bog and fen peatland types, and large within-site spatiotemporal variability. We found that microtopography in the bog was associated with consistent differences in most biogeochemical variables. Temporal changes in dissolved solute chemistry, particularly base cations (Na(+), Ca(2+) and Mg(2+)), were statistically significant in the intermediate fen, likely a result of a dynamic connection between surficial waters and mineral-rich deep groundwater. In both the bog and fen, concentrations of SO4(2-) showed considerable spatial variability, and a significant decrease in concentrations over the study period. The observed variability in peatland pore-water biogeochemistry over such small spatial and temporal scales suggests that under-sampling in

  11. Risk assessment for produced water discharges to Louisiana open bays. Final report

    International Nuclear Information System (INIS)

    Meinhold, A.F.; DePhillips, M.P.; Holtzman, S.

    1996-01-01

    The US Department of Energy (USDOE) has a program of research in the environmental aspects of oil and gas extraction. This sampling project will characterize the environmental impacts associated with the discharge of naturally occurring radioactive materials (NORM), metals and organics in produced water. This report is part of a series of studies of the health and ecological risks from discharges of produced water to the Gulf of Mexico, supported by the USDOE. These assessments are being coordinated with the field study, using the collected data to perform human health and ecological risk assessments. These assessments will provide input to regulators in the development of guidelines and permits, and to industry in the development and use of appropriate discharge practices. The initial human health and ecological risk assessments consist of conservative screening analyses meant to identify potentially important contaminants, and to eliminate others from further consideration. More quantitative assessments were done for contaminants identified, in the screening analysis, as being of potential concern. Section 2 gives an overview of human health and ecological risk assessment to help put the analyses presented here in perspective. Section 3 provides the hazard assessment portion of the risk assessment, and identifies the important receptors and pathways of concern. Section 3 also outlines the approach taken to the risk assessments presented in the rest of the report. The remaining sections (4 through 9) present the human health and ecological risk assessments for discharges of produced water to open bays in Louisiana

  12. Evaluation of the concentration of heavy metals in sea water, silt and rock oysters, Crassostrea iridescens, from Manzanillo bay

    International Nuclear Information System (INIS)

    Guerrero Carbajal, Y.C.

    1993-01-01

    Some essential metals such as Fe, Ni, Cu and Zn were evaluated by X-ray spectroscopy in water, soil and rock oyster Crassostrea iridescens from Manzanillo Bay. Four samplings were taken every two months during 1991. Concentration range on liofilized oysters for Fe was determined between 76 and 172 μ g/g dry weight, Ni 9-21 μ g/g dry weight, Cu 21-123 μ g/g dry weight and Zn 216-885 μ g/g dry weight. Ni concentration was above the toxicological tolerance level for crustaceans (5 μ g/g); Cu was above maxima permission limited (MPL) from FAO for molluscs (70 μ g/g); Zn was below MPL for oysters (1000 μ g/g). For Fe there is no MPL for oyster or any other aquatic organisms. Concentration and accumulation factors for the elements measured suggested the filtration oyster activity. Fe concentration range in water was 27-2266 μ g/l. This value is above the ecological aquatic life criteria in Mexico (50 μ g/l). For Cu the concentration range was 4-536 μ g/l., which is above the MPL for Mexican Legislation (5 μ g/l). Chemical elements detected in soil were the essential metal mentioned before. However, the heavy metals concentrations for soil, from Manzanillo Bay, were higher than those reported in other polluted regions in both Mexican coasts. Concentration range for Fe was 30661-76332 μ g/g, Ni 19-180 μ g/g, Cu 56-270 μ g/g and Zn 33-1377 μ g/g. Contamination problem in Manzanillo Bay must be considered as an evidence of potential risk, since the essential metals are reaching levels that could endanger aquatic life. (Author). 87 refs, 20 figs, 6 tabs

  13. Understanding nutrients in the Chesapeake Bay watershed and implications for management and restoration: the Eastern Shore

    Science.gov (United States)

    Ator, Scott W.; Denver, Judith M.

    2015-03-12

    The Eastern Shore includes only a small part of the Chesapeake Bay watershed, but contributes disproportionately large loads of the excess nitrogen and phosphorus that have contributed to ecological and economic degradation of the bay in recent decades. Chesapeake Bay is the largest estuary in the United States and a vital ecological and economic resource. The bay and its tributaries have been degraded in recent decades by excessive nitrogen and phosphorus in the water column, however, which cause harmful algal blooms and decreased water clarity, submerged aquatic vegetation, and dissolved oxygen. The disproportionately large nitrogen and phosphorus yields from the Eastern Shore to Chesapeake Bay are attributable to human land-use practices as well as natural hydrogeologic and soil conditions. Applications of nitrogen and phosphorus compounds to the Eastern Shore from human activities are intensive. More than 90 percent of nitrogen and phosphorus reaching the land in the Eastern Shore is applied as part of inorganic fertilizers or manure, or (for nitrogen) fixed directly from the atmosphere in cropland. Also, hydrogeologic and soil conditions promote the movement of these compounds from application areas on the landscape to groundwater and (or) surface waters, and the proximity of much of the Eastern Shore to tidal waters limits opportunities for natural removal of these compounds in the landscape. The Eastern Shore only includes 7 percent of the Chesapeake Bay watershed, but receives nearly twice as much nitrogen and phosphorus applications (per area) as the remainder of the watershed and yields greater nitrogen and phosphorus, on average, to the bay. Nitrogen and phosphorus commonly occur in streams at concentrations that may adversely affect aquatic ecosystems and have increased in recent decades.

  14. Genetic differentiation of the Kittlitz's Murrelet Brachyramphus brevirostris in the Aleutian Islands and Gulf of Alaska

    Science.gov (United States)

    Birt, T.P.; Mackinnon, D.; Piatt, John F.; Friesen, Vicki L.

    2011-01-01

    Information about the distribution of genetic variation within and among local populations of the Kittlitz's Murrelet Brachyramphus brevirostris is needed for effective conservation of this rare and declining species. We compared variation in a 429 base pair fragment of the mitochondrial control region and 11 microsatellite loci among 53 Kittlitz's Murrelets from three sites in the western Aleutian Islands (Attu Island) and Gulf of Alaska (Glacier Bay and Kachemak Bay). We found that birds in these two regions differ genetically in three assessments: (1) global and pairwise indices of genetic differentiation were significantly greater than zero, (2) mitochondrial haplotypes differed by a minimum of nine substitutions, and (3) molecular assignments indicated little gene flow between regions. The data suggest that birds in these regions have been genetically isolated for an extended period. We conclude that Kittlitz's Murrelets from Attu Island and from the Gulf of Alaska represent separate evolutionarily significant units, and should be treated as such for conservation. Genetic data for Kittlitz's Murrelets from the remainder of the breeding range are urgently needed.

  15. Occurance and survival of Vibrio alginolyticus in Tamouda Bay (Morocco).

    Science.gov (United States)

    Sabir, M; Cohen, N; Boukhanjer, A; Ennaji, M M

    2011-10-15

    The objectives of this study were to investigate the spatial and seasonal fluctuations of Vibrio alginolyticus in marine environment of the Tamouda Bay on the Mediterranean coast of Morocco and to determine the dominant factors of the environment that govern these fluctuations. The samples (sea water, plankton, shellfish and sediment) were collected fortnightly for two years from three study sites on the coast Tamouda Bay in northern Morocco. The charge of Vibrio alginolyticus is determined by MPN method. The physicochemical parameters including temperature of sea water, pH, salinity, turbidity and chlorophyll a concentration were determined. Analysis of variance of specific variables and several principal component analyses showed that the temperature of seawater is the major determinant of seasonal distribution of Vibrio alginolyticus. The results showed a positive linear correlation between Vibrio alginolyticus and the water temperature, pH, turbidity and chlorophyll a. Similarly, there are seasonal variations and spatial of Vibrio alginolyticus in marine environment of the Tamouda bay and the highest concentrations were recorded in both years of study during the warm season whereas it was minimal during the cold season. Linear positive correlation was recorded between Vibrio alginolyticus populations in all ecological types of samples studied.

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

    Science.gov (United States)

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

    2004-01-01

    San Francisco Bay, one of the world's finest natural harbors and a major center for maritime trade, is referred to as the 'Gateway to the Pacific Rim.' The bay is an urbanized estuary that is considered by many to be the major estuary in the United States most modified by man's activities. The population around the estuary has grown rapidly since the 1850's and now exceeds 7 million people. The San Francisco Bay area's economy ranks as one of the largest in the world, larger even than that of many countries. More than 10 million tourists are estimated to visit the bay region each year. The bay area's population and associated development have increasingly changed the estuary and its environment. San Francisco Bay and the contiguous Sacramento-San Joaquin Delta encompass roughly 1,600 square miles (4,100 km2) and are the outlet of a major watershed that drains more than 40 percent of the land area of the State of California. This watershed provides drinking water for 20 million people (two thirds of the State's population) and irrigates 4.5 million acres of farmland and ranchland. During the past several decades, much has been done to clean up the environment and waters of San Francisco Bay. Conservationist groups have even bought many areas on the margins of the bay with the intention of restoring them to a condition more like the natural marshes they once were. However, many of the major manmade changes to the bay's environment occurred so long ago that the nature of them has been forgotten. In addition, many changes continue to occur today, such as the introduction of exotic species and the loss of commercial and sport fisheries because of declining fish populations. The economy and population of the nine counties that surround the bay continue to grow and put increasing pressure on the bay, both direct and indirect. Therefore, there are mixed signals for the future health and welfare of San Francisco Bay. The San Francisco Bay estuary consists of three

  17. Phytoplankton community structure in local water types at a coastal site in north-western Bay of Bengal.

    Science.gov (United States)

    Baliarsingh, S K; Srichandan, Suchismita; Lotliker, Aneesh A; Sahu, K C; Srinivasa Kumar, T

    2016-07-01

    A comprehensive analysis on seasonal distribution of phytoplankton community structure and their interaction with environmental variables was carried out in two local water types (type 1  30 m isobath) at a coastal site in north-western Bay of Bengal. Phytoplankton community was represented by 211 taxa (146 marine, 37 fresh, 2 brackish, 20 marine-fresh, and 6 marine-brackish-fresh) belonging to seven major groups including 45 potential bloom forming and 22 potential toxin producing species. The seasonal variability depicted enrichment of phytoplankton during pre-monsoon in both water types. Total phytoplankton abundance pattern observed with inter-annual shift during monsoon and post-monsoon period at both water types. In both water types, diatom predominance was observed in terms of species richness and abundance comprising of centric (82 sp.) and pennate (58 sp.) forms. Pennate diatoms, Thalassiothrix longissima and Skeletonema costatum preponderated in both the water types. The diatom abundance was higher in type 1 in comparison to type 2. In general, SiO4 found to fuel growth of the dominant phytoplankton group, diatom in both the water types despite comparative lower concentration of other macronutrients in type 2.

  18. Multiple stressor effects on water quality in Poplar Bay, Lake of the Woods, Canada: a midge-based assessment of hypolimnetic oxygen conditions over the last two centuries

    Directory of Open Access Journals (Sweden)

    Jamie C. Summers

    2012-01-01

    Full Text Available Chironomid and Chaoborus (midge remains preserved in a dated sediment core from Poplar Bay, Lake of the Woods (LOW, Ontario, Canada, were used to assess the effects of multiple stressors (e.g., recent warming and shoreline development on water quality over the past ~200 years. As monitoring data for LOW do not extend beyond recent decades, paleolimnological methods are used to reconstruct long-term limnological trends and to establish pre-disturbance conditions. The effects of recent warming and shoreline development on Poplar Bay water quality are examined using an index of hypolimnetic oxygen (O2 status based on the ratio of Chaoborus to chironomid remains (chaob:chir and a midge-inferred volume-weighted hypolimnetic oxygen (VWHO model. Our paleolimnological data indicate that hypolimnetic [O2] in Poplar Bay have been historically hypoxic (1-4 mg O2 L-1 but have declined further (generally <2 mg O2 L-1 over the last few decades. Significant relationships between air temperature and midge data indicate that substantial warming starting in the late-1970s has triggered a marked response in the midge assemblages that pre-dates the onset of cottage development (mid-1990s. These findings complement a diatom-based study on the same sediment core, likewise suggesting that recent warming has played a prominent role in structuring limnetic communities. However, it is likely that the full, compounded effects of recent warming and shoreline development have not yet been realized. Our study highlights the complexity of multiple stressor systems, such as Poplar Bay, and emphasizes the benefits of using multiple, independent lines of paleoenvironmental evidence in gaining a more complete understanding of historical water quality.

  19. Imbalance of Nature due to Anthropogenic Activities in the Bay of Bacorehuis, Sinaloa, Mexico

    Science.gov (United States)

    Torrecillas Nunez, C.; Cárdenas Cota, H.

    2013-05-01

    Pollution is further enhancing water scarcity by reducing water usability downstream, globally the most prevalent water quality problem is eutrophication, a result of high-nutrient loads, which substantially impairs beneficial uses of water. Projected food production needs and increasing wastewater effluents associated with an increasing population over the next three decades suggest a 10%-15% increase in the river input of nitrogen loads into coastal ecosystems (UNO, 2009). Our study in the Bay of Bacorehuis in the State of Sinaloa, which was carried out due to a request from local fishermen who wanted to find out the reason for fishing stocks depletion, confirmed this trend with the consequent imbalance of nature. Sinaloa depends heavily on intensive agricultural production to support its economy which in turn relies on water irrigation and the application of agro-chemicals. The research project included a desk top study of geophysical and environmental factors as well as sampling and testing of the water. In addition we carried out socio-economic research to find out the impact on the local community of the imbalance caused by anthropogenic activities in the watershed upstream from the Bay. Our research established that the Bay of Bacorehuis is contaminated by organic matter, bacteria coliforms, pesticides and mercury due to the discharge of surplus runoff generated by irrigation of farmlands into drainage networks as well as the discharge of untreated industrial and domestic wastewater form more than 24,000 inhabitants. The main contaminants detected in the water bodies were organic matter, faecal coliforms, mercury, dimethoate, endosulfan, heptachlor, DDE, DDT, organonitrogen, synthetic pyrethroid, chlorothalonil, ethion, endosulfan, diazinon, malathion and chlorpyrifos. Contaminants in sediments included the pesticides endosulfan, heptachlor, DDE, DDT, organophosphates, organonitrogen and synthetic pyrethroids. Natural water courses have been highly modified

  20. Azimuth selection for sea level measurements using geodetic GPS receivers

    Science.gov (United States)

    Wang, Xiaolei; Zhang, Qin; Zhang, Shuangcheng

    2018-03-01

    Based on analysis of Global Positioning System (GPS) multipath signals recorded by a geodetic GPS receiver, GPS Reflectometry (GPS-R) has demonstrated unique advantages in relation to sea level monitoring. Founded on multipath reflectometry theory, sea level changes can be measured by GPS-R through spectral analysis of recorded signal-to-noise ratio data. However, prior to estimating multipath parameters, it is necessary to define azimuth and elevation angle mask to ensure the reflecting zones are on water. Here, a method is presented to address azimuth selection, a topic currently under active development in the field of GPS-R. Data from three test sites: the Kachemak Bay GPS site PBAY in Alaska (USA), Friday Harbor GPS site SC02 in the San Juan Islands (USA), and Brest Harbor GPS site BRST in Brest (France) are analyzed. These sites are located in different multipath environments, from a rural coastal area to a busy harbor, and they experience different tidal ranges. Estimates by the GPS tide gauges at azimuths selected by the presented method are compared with measurements from physical tide gauges and acceptable correspondence found for all three sites.

  1. Shallow-water, nearshore current dynamics in Algoa Bay, South ...

    African Journals Online (AJOL)

    Nearshore currents play a vital role in the transport of eggs and larval stages of fish. However, little is known about their complexity and the implications for dispersal of fish larvae. The study describes the complexity of the shallow nearshore environment in eastern Algoa Bay, on the south-east coast of South Africa, and its ...

  2. Lithostratigraphic, borehole-geophysical, hydrogeologic, and hydrochemical data from the East Bay Plain, Alameda County, California

    Science.gov (United States)

    Sneed, Michelle; Orlando, Patricia v.P.; Borchers, James W.; Everett, Rhett; Solt, Michael; McGann, Mary; Lowers, Heather; Mahan, Shannon

    2015-01-01

    The U.S. Geological Survey, in cooperation with the East Bay Municipal Utility District, carried out an investigation of aquifer-system deformation associated with groundwater-level changes at the Bayside Groundwater Project near the modern San Francisco Bay shore in San Lorenzo, California. As a part of the Bayside Groundwater Project, East Bay Municipal Utility District proposed an aquifer storage and recovery program for 1 million gallons of water per day. The potential for aquifer-system compaction and expansion, and related subsidence, uplift, or both, resulting from aquifer storage and recovery activities were investigated and monitored in the Bayside Groundwater Project. In addition, baseline analysis of groundwater and substrata properties were performed to assess the potential effect of such activities. Chemical and physical data, obtained from the subsurface at four sites on the east side of San Francisco Bay in the San Lorenzo and San Leandro areas of the East Bay Plain, Alameda County, California, were collected during the study. The results of the study were provided to the East Bay Municipal Utility District and other agencies to evaluate the chemical and mechanical responses of aquifers underlying the East Bay Plain to the future injection and recovery of imported water from the Sierra Nevada of California.

  3. Status of macrobenthic community of Manifa-Tanajib Bay System of Saudi Arabia based on a once-off sampling event

    KAUST Repository

    Joydas, Thadickal Viswanathan; Krishnakumar, P. K.; Qurban, Mohammad Ali; Ali, Said M.; Al-Suwailem, Abdulaziz M.; Al-Abdulkader, Khaled

    2011-01-01

    Shallow water bays located in the western Arabian Gulf experience harsh environmental conditions. Some of these bays, including Manifa-Tanajib Bay System (MTBS), were also exposed to the 1991 oil pollution event. This study investigates the status

  4. Heavy metals in tissues of water fowl from the Chesapeake Bay, USA. [Clangula hyemalis; Melanitta deglandi; Anas platyrhynchos; Anas rubripes; Anas strepera

    Energy Technology Data Exchange (ETDEWEB)

    Di Giulio, R; Scanlon, P F

    1984-01-01

    Concentrations of cadmium, lead, copper and zinc were measured in 774 livers, 266 kidneys and 271 ulnar bones from 15 species of ducks obtained from the Chesapeake Bay region. A major purpose of this study was to elucidate relationships between food habits and tissue accumulations of heavy metals in Chesapeake Bay water fowl. Liver and kidney concentrations of cadmium were highest among two carnivorous seaduck species, Clangula hyemalis and Melanitta deglandi. In contrast, lead concentrations in tissues were generally highest in largely herbivorous species, such as Anas platyrhynchos, Anas rubripes and Anas strepera. Spent shot may be an important source for tissue burdens of lead in these ducks. No marked trends were observed between food habits and tissue concentrations of the nutrient elements, copper and zinc.

  5. High-pressure liquid chromatographic assay of Bay n 7133 in human serum.

    OpenAIRE

    Fasching, C E; Hughes, C E; Hector, R F; Peterson, L R

    1984-01-01

    A high-pressure liquid chromatographic method that includes a Sep-Pak (Waters Associates, Inc., Milford , Mass.) preparation of human serum was employed for the quantitative assay of Bay n 7133. Drug levels of 0.1 to 20 micrograms/ml could be detected. No interference from amphotericin B was found in the chromatographic analysis of Bay n 7133.

  6. 76 FR 1386 - Safety Zone; Centennial of Naval Aviation Kickoff, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2011-01-10

    ...-AA00 Safety Zone; Centennial of Naval Aviation Kickoff, San Diego Bay, San Diego, CA AGENCY: Coast... zone on the navigable waters of San Diego Bay in San Diego, CA in support of the Centennial of Naval... February 12, 2010, the Centennial of Naval Aviation Kickoff will take place in San Diego Bay. In support of...

  7. Sources and transformations of dissolved lignin phenols and chromophoric dissolved organic matter in Otsuchi Bay, Japan

    Directory of Open Access Journals (Sweden)

    Chia-Jung eLu

    2016-06-01

    Full Text Available Dissolved lignin phenols and optical properties of dissolved organic matter (DOM were measured to investigate the sources and transformations of terrigenous DOM (tDOM in Otsuchi Bay, Japan. Three rivers discharge into the bay, and relatively high values of syringyl:vanillyl phenols (0.73 ± 0.07 and cinnamyl:vanillyl phenols (0.33 ± 0.10 indicated large contributions of non-woody angiosperm tissues to lignin and tDOM. The physical mixing of river and seawater played an important role in controlling the concentrations and distributions of lignin phenols and chromophoric DOM (CDOM optical properties in the bay. Lignin phenol concentrations and the CDOM absorption coefficient at 350 nm, a(350, were strongly correlated in river and bay waters. Measurements of lignin phenols and CDOM in bay waters indicated a variety of photochemical and biological transformations of tDOM, including oxidation reactions, photobleaching and a decrease in molecular weight. Photodegradation and biodegradation of lignin and CDOM were investigated in decomposition experiments with river water and native microbial assemblages exposed to natural sunlight or kept in the dark. There was a rapid and substantial removal of lignin phenols and CDOM during the first few days in the light treatment, indicating transformations of tDOM and CDOM can occur soon after discharge of buoyant river water into the bay. The removal of lignin phenols was slightly greater in the dark (34% than in the light (30% during the remaining 59 days of the incubation. Comparison of the light and dark treatments indicated biodegradation was responsible for 67% of total lignin phenol removal during the 62-day incubation exposed to natural sunlight, indicating biodegradation is a dominant removal process in Otsuchi Bay.

  8. Water quality measurements in San Francisco Bay by the U.S. Geological Survey, 1969-2015.

    Science.gov (United States)

    Schraga, Tara S; Cloern, James E

    2017-08-08

    The U.S. Geological Survey (USGS) maintains a place-based research program in San Francisco Bay (USA) that began in 1969 and continues, providing one of the longest records of water-quality measurements in a North American estuary. Constituents include salinity, temperature, light extinction coefficient, and concentrations of chlorophyll-a, dissolved oxygen, suspended particulate matter, nitrate, nitrite, ammonium, silicate, and phosphate. We describe the sampling program, analytical methods, structure of the data record, and how to access all measurements made from 1969 through 2015. We provide a summary of how these data have been used by USGS and other researchers to deepen understanding of how estuaries are structured and function differently from the river and ocean ecosystems they bridge.

  9. 75 FR 32209 - North San Pablo Bay Restoration and Reuse Project

    Science.gov (United States)

    2010-06-07

    ... promote the expanded beneficial use of recycled water in the North Bay region. In this way, water demand... XVI of Public Law 102-575, as amended, which provides a mechanism for Federal participation and cost... Napa counties are facing long-term water supply shortfalls. Surface and groundwater supplies within...

  10. 33 CFR 334.640 - Gulf of Mexico south of Apalachee Bay, Fla.; Air Force rocket firing range.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Gulf of Mexico south of Apalachee Bay, Fla.; Air Force rocket firing range. 334.640 Section 334.640 Navigation and Navigable Waters... REGULATIONS § 334.640 Gulf of Mexico south of Apalachee Bay, Fla.; Air Force rocket firing range. (a) The...

  11. A comparative study of vertical stabilities in the Arabian sea and Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sastry, J.S.; Rao, D.P.

    Stabilities in the upper 300 m in the Arabian Sea and the Bay of Bengal are computed and presented seasonwise. The water column in the Bay of Bengal is more strongly stratified than that in the Arabian Sea. These studies suggest that the vertical...

  12. Evaluation of dredged material proposed for ocean disposal from Red Hook/Bay Ridge project areas, New York

    Energy Technology Data Exchange (ETDEWEB)

    Pinza, M.R.; Barrows, E.S.; Borde, A.B. [Battelle/Marine Sciences Lab., Sequim, WA (United States)

    1996-09-01

    The objective of the Red HookIBay Ridge project was to evaluate proposed dredged material from these two areas to determine its suitability for unconfined ocean disposal at the Mud Dump Site. Sediment samples were collected from the Red Hook/Bay Ridge project areas. Tests and analyses were conducted. The evaluation of proposed dredged material from the Red Hook/Bay Ridge project areas consisted of bulk sediment chemical analyses, chemical analyses of dredging site water and elutriate, water-column and benthic acute toxicity tests. Twenty-four individual sediment core samples were collected from these two areas and analyzed for grain size, moisture content, and total organic carbon (TOC). Three composite sediment samples, representing Red Hook Channel and the two Bay Ridge Reaches to be dredged, were analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAH), and 1,4-dichlorobenzene. Dredging site water and elutriate water, which is prepared from the suspended-particulate phase (SPP) of the three Red Hook Bay Ridge sediment composites, were analyzed for metals, pesticides, and PCBS. Benthic acute toxicity tests were performed. Water-column or SPP toxicity tests were performed. Bioaccumulation tests were also conducted.

  13. Inputs and spatial distribution patterns of Cr in Jiaozhou Bay

    Science.gov (United States)

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

    2018-03-01

    Cr pollution in marine bays has been one of the critical environmental issues, and understanding the input and spatial distribution patterns is essential to pollution control. In according to the source strengths of the major pollution sources, the input patterns of pollutants to marine bay include slight, moderate and heavy, and the spatial distribution are corresponding to three block models respectively. This paper analyzed input patterns and distributions of Cr in Jiaozhou Bay, eastern China based on investigation on Cr in surface waters during 1979-1983. Results showed that the input strengths of Cr in Jiaozhou Bay could be classified as moderate input and slight input, and the input strengths were 32.32-112.30 μg L-1 and 4.17-19.76 μg L-1, respectively. The input patterns of Cr included two patterns of moderate input and slight input, and the horizontal distributions could be defined by means of Block Model 2 and Block Model 3, respectively. In case of moderate input pattern via overland runoff, Cr contents were decreasing from the estuaries to the bay mouth, and the distribution pattern was parallel. In case of moderate input pattern via marine current, Cr contents were decreasing from the bay mouth to the bay, and the distribution pattern was parallel to circular. The Block Models were able to reveal the transferring process of various pollutants, and were helpful to understand the distributions of pollutants in marine bay.

  14. A nearly orthogonal 2D grid system in solving the shallow water equations in the head bay of Bengal

    International Nuclear Information System (INIS)

    Roy, G.D. . E.mail: roy_gd@hotmail.com; Hussain, Farzana . E.mail: farzana@sust.edu

    2001-11-01

    A typical nearly orthogonal grid system is considered to solve the shallow water equations along the head bay of Bengal. A pencil of straight lines at uniform angular distance through a suitable origin, O at the mean sea level (MSL), are considered as a system of grid lines. A system of concentric and uniformly distributed ellipses with center at O is considered as the other system of grid lines. In order to solve the shallow water equations numerically, a system of transformations is applied so that the grid system in the transformed domain becomes a rectangular one. Shallow water equations are solved using appropriate initial and boundary conditions to estimate the water level due to tide and surge. The typical grid system is found to be suitable in incorporating the bending of the coastline and the island boundaries accurately in the numerical scheme along the coast of Bangladesh. (author)

  15. 76 FR 18395 - Safety Zone; Naval Air Station Corpus Christi Air Show, Oso Bay, Corpus Christi, TX

    Science.gov (United States)

    2011-04-04

    ...-AA00 Safety Zone; Naval Air Station Corpus Christi Air Show, Oso Bay, Corpus Christi, TX AGENCY: Coast... zone on the navigable waters of Oso Bay in Corpus Christi, Texas in support of the 2011 Naval Air... entities and very few recreational fisherman utilize this section of Oso Bay, the restriction of vessel...

  16. Evaluation of Pollution Level in Zolotoy Rog Bay (Peter the Great Gulf, the Sea of Japan)

    Science.gov (United States)

    Kazachkova, Y.; Lazareva, L.; Petukhov, V.

    2017-11-01

    The results of the hydrochemical research of water and bottom sediments of the Zolotoy Rog Bay in July 2015 are presented below. It is shown that, as a result of a large amount of polluted sewage entering The Zolotoy Rog Bay, the concentrations of organic substances (BOD5) and petroleum hydrocarbons in the water exceed the MPC. The concentrations of heavy metals in soils exceed both the background level and the level of permissible values. As a result of the calculation of the bottom accumulation (CBA) coefficient for oil hydrocarbons, the situation in the Zolotoy Rog Bay can be classified as an ecological disaster. According to the total pollution index (Zc) of heavy metals, the bottom sediments of the Zolotoy Rog Bay are characterized as strongly and very strongly polluted.

  17. Hydrophysical correlation and water mass indication of optical physiological parameters of picophytoplankton in Prydz Bay during autumn 2008.

    Science.gov (United States)

    Zhang, Fang; Ma, Yuxin; Lin, Ling; He, Jianfeng

    2012-12-01

    Flow cytometry (FCM) is efficient in detecting both abundance and optical physiological parameters including cell size and cellular carbon content-side scatter (SSC), carotenoids-green and orange fluorescence (FL1 and FL2), and red fluorescence-chlorophylls (FL3) can be obtained by FCM. The utilization of these physiological parameters in indicating water masses in Prydz Bay was investigated for the first time. Picophytoplankton were very sensitive to hydrophysical changes and present distinct characteristics of water masses: Picophytoplankton in water closer to the Amery Ice Shelf were more affected by salinity than by temperature, while temperature became more important than salinity the nearer the picophytoplankton were to the deep sea. The picophytoplankton dealt with declines in light by increasing the size of cells, which increase the fixation of carbon. This can also be increased by high temperature and salinity. Pure water masses can increase the content of chlorophylls and cellular carbon. Generally, the distributions of all the five parameters at upper water depths were less affected by temperature and salinity than by water masses; and these parameters can be as indicators to Summer Surface Water (SSW), Winter Water (WW) and Continental Shelf Water (CSW). Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Modeling Trace Element Concentrations in the San Francisco Bay Estuary from Remote Measurement of Suspended Solids

    Science.gov (United States)

    Press, J.; Broughton, J.; Kudela, R. M.

    2014-12-01

    Suspended and dissolved trace elements are key determinants of water quality in estuarine and coastal waters. High concentrations of trace element pollutants in the San Francisco Bay estuary necessitate consistent and thorough monitoring to mitigate adverse effects on biological systems and the contamination of water and food resources. Although existing monitoring programs collect annual in situ samples from fixed locations, models proposed by Benoit, Kudela, & Flegal (2010) enable calculation of the water column total concentration (WCT) and the water column dissolved concentration (WCD) of 14 trace elements in the San Francisco Bay from a more frequently sampled metric—suspended solids concentration (SSC). This study tests the application of these models with SSC calculated from remote sensing data, with the aim of validating a tool for continuous synoptic monitoring of trace elements in the San Francisco Bay. Using HICO imagery, semi-analytical and empirical SSC algorithms were tested against a USGS dataset. A single-band method with statistically significant linear fit (p Arsenic, Iron, and Lead in the southern region of the Bay were found to exceed EPA water quality criteria for human health and aquatic life. The results of this study demonstrate the potential of monitoring programs using remote observation of trace element concentrations, and provide the foundation for investigation of pollutant sources and pathways over time.

  19. Lost lake - restoration of a Carolina bay

    Energy Technology Data Exchange (ETDEWEB)

    Hanlin, H.G.; McLendon, J.P. [Univ. of South Carolina, Aiken, SC (United States). Dept. of Biology and Geology; Wike, L.D. [Univ. of South Carolina, Aiken, SC (United States). Dept. of Biology and Geology]|[Westinghouse Savannah River Co., Aiken, SC (United States). Savannah River Technology Center; Dietsch, B.M. [Univ. of South Carolina, Aiken, SC (United States). Dept. of Biology and Geology]|[Univ. of Georgia, Aiken, SC (United States)

    1994-09-01

    Carolina bays are shallow wetland depressions found only on the Atlantic Coastal Plain. Although these isolated interstream wetlands support many types of communities, they share the common features of having a sandy margin, a fluctuating water level, an elliptical shape, and a northwest to southeast orientation. Lost Lake, an 11.3 hectare Carolina bay, was ditched and drained for agricultural production before establishment of the Savannah River Site in 1950. Later it received overflow from a seepage basin containing a variety of chemicals, primarily solvents and some heavy metals. In 1990 a plan was developed for the restoration of Lost Lake, and restoration activities were complete by mid-1991. Lost Lake is the first known project designed for the restoration and recovery of a Carolina bay. The bay was divided into eight soil treatment zones, allowing four treatments in duplicate. Each of the eight zones was planted with eight species of native wetland plants. Recolonization of the bay by amphibians and reptiles is being evaluated by using drift fences with pitfall traps and coverboard arrays in each of the treatment zones. Additional drift fences in five upland habitats were also established. Hoop turtle traps, funnel minnow traps, and dip nets were utilized for aquatic sampling. The presence of 43 species common to the region has been documented at Lost Lake. More than one-third of these species show evidence of breeding populations being established. Three species found prior to the restoration activity and a number of species common to undisturbed Carolina bays were not encountered. Colonization by additional species is anticipated as the wetland undergoes further succession.

  20. Seasonal variability of coastal water quality in bay of Bengal and Palk Strait, Tamilnadu, Southeast Coast of India

    Directory of Open Access Journals (Sweden)

    Viswanathan Srinivasan

    2013-10-01

    Full Text Available The aim of this work was to study the physicochemical parameters of water quality collected from 12 sampling stations from Topputhurai to Muthupet in Vedaranyam located on the southeast coast of India from January to December 2008. Results showed that the DO and nutrients were the maximum in the Bay of Bengal during the monsoon period. High concentration of the nutrients in summer season was obtained near the Muthupet mangroves compared to the Palk Strait, which showed that this acted as a source of nutrients to the adjacent coastal waters. Low concentrations of the nutrients observed in the monsoon could be attributed to the terrestrial runoff from Muthupet lagoon. The physicochemical characteristics of coastal waters between the Point Calimere and Muthupet could be used as a baseline data for the monitoring, conservation and management of Point Calimere Wildlife and Bird sanctuary, Great Vedaranyam swamp and Muthupet mangrove ecosystem.

  1. The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay

    Science.gov (United States)

    Irby, Isaac D.; Friedrichs, Marjorie A. M.; Da, Fei; Hinson, Kyle E.

    2018-05-01

    The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic-biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea level will increase estuarine circulation, reducing residence time in bottom waters and increasing stratification. As a result, oxygen concentrations in bottom waters are projected to increase, while oxygen concentrations at mid-depths (3 < DO < 5 mg L-1) will typically decrease. Changes in precipitation are projected to deliver higher winter and spring freshwater flow and nutrient loads, fueling increased primary production. Together, these multiple climate impacts will lower DO throughout the Chesapeake Bay and negatively impact progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load. However, this research also shows that the potential impacts of climate change will be significantly smaller than improvements in DO expected in response to the required nutrient reductions, especially at the anoxic and hypoxic levels. Overall, increased temperature exhibits the strongest control on the change in future DO concentrations, primarily due to decreased solubility, while sea level rise is expected to exert a small positive impact and increased winter river flow is anticipated to exert a small negative impact.

  2. Goddard DEVELOP Students: Using NASA Remote Sensing Technology to Study the Chesapeake Bay Watershed

    Science.gov (United States)

    Moore, Rachel

    2011-01-01

    The DEVELOP National Program is an Earth Science research internship, operating under NASA s Applied Sciences Program. Each spring, summer, and fall, DEVELOP interns form teams to investigate Earth Science related issues. Since the Fall of 2003, Goddard Space Flight Center (GSFC) has been home to one of 10 national DEVELOP teams. In past terms, students completed a variety of projects related to the Applied Sciences Applications of National Priority, such as Public Health, Natural Disasters, Water Resources, and Ecological Forecasting. These projects have focused on areas all over the world, including the United States, Africa, and Asia. Recently, Goddard DEVELOP students have turned their attention to a local environment, the Chesapeake Bay Watershed. The Chesapeake Bay Watershed is a complex and diverse ecosystem, spanning approximately 64,000 square miles. The watershed encompasses parts of six states: Delaware, Maryland, New York, Pennsylvania, Virginia, and West Virginia, as well as the District of Columbia. The Bay itself is the biggest estuary in the United States, with over 100,000 tributaries feeding into it. The ratio of fresh water to salt water varies throughout the Bay, allowing for a variety of habitats. The Bay s wetlands, marshes, forests, reefs, and rivers support more than 3,600 plant and animal species, including birds, mammals, reptiles, amphibians, fish, and crabs. The Bay is also commercially significant. It is ranked third in the nation in fishery catch, and supplies approximately 500 million pounds of seafood annually. In addition to its abundant flora and fauna, the Chesapeake Bay watershed is home to approximately 16.6 million people, who live and work throughout the watershed, and who use its diverse resources for recreational purposes. Over the past several decades, the population throughout the watershed has increased rapidly, resulting in land use changes, and ultimately decreasing the health of the Chesapeake Bay Watershed. Over the

  3. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California: 2014

    Science.gov (United States)

    Cain, Daniel J.; Thompson, Janet K.; Crauder, Jeff; Parcheso, Francis; Stewart, Robin; Kleckner, Amy E.; Dyke, Jessica; Hornberger, Michelle I.; Luoma, Samuel N.

    2015-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer (km) south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2014 to December 2014. These append to long-term datasets extending back to 1974, and serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994. 

  4. Summary of oceanographic and water–quality measurements in West Falmouth Harbor and Buzzards Bay, Massachusetts, 2009–2010

    Science.gov (United States)

    Ganju, Neil K.; Dickhudt, Patrick J.; Thomas, Jennifer A.; Borden, Jonathan; Sherwood, Christopher R.; Montgomery, Ellyn T.; Twomey, Erin R.; Martini, Marinna A.

    2011-01-01

    This data report presents oceanographic and water-quality observations made at six locations in West Falmouth Harbor and Buzzards Bay, Massachusetts, from August 2009 to September 2010. Both Buzzards Bay and West Falmouth Harbor are estuarine embayments; the input of freshwater on the eastern margin of Buzzards Bay adjacent to Cape Cod and West Falmouth Harbor is largely due to groundwater. In West Falmouth Harbor, the groundwater that seeps into the harbor is characterized by relatively high levels of nitrate. This high nitrate load has modified the ecology of the harbor (Howes and others, 2006) and may be a significant source of nitrate to Buzzards Bay during seasons with low biological nitrate uptake. The U.S. Geological Survey undertook these measurements to improve understanding of circulation, residence time, and water quality in the harbor and bay. We set up and monitored multiple sites in both Buzzards Bay and West Falmouth Harbor, measuring depth, water velocity,salinity, pH, dissolved oxygen, chlorophyll-a, and nitrate concentration. In this report we present the processed time-series data at these locations and provide access to the data and metadata. The results will be used to understand circulation mechanisms and verify numerical models of hydrodynamics and biogeochemistry.

  5. Submersed aquatic vegetation in Chesapeake Bay: Sentinel species in a changing world

    Science.gov (United States)

    Orth, Robert J.; Dennison, William C.; Lefcheck, Jonathon S.; Gurbisz, Cassie; Hannam, Michael; Keisman, Jennifer; Landry, J. Brooke; Moore, Kenneth A.; Murphy, Rebecca R.; Patrick, Christopher J.; Testa, Jeremy; Weller, Donald E.; Wilcox, David J.

    2017-01-01

    Chesapeake Bay has undergone profound changes since European settlement. Increases in human and livestock populations, associated changes in land use, increases in nutrient loadings, shoreline armoring, and depletion of fish stocks have altered the important habitats within the Bay. Submersed aquatic vegetation (SAV) is a critical foundational habitat and provides numerous benefits and services to society. In Chesapeake Bay, SAV species are also indicators of environmental change because of their sensitivity to water quality and shoreline development. As such, SAV has been deeply integrated into regional regulations and annual assessments of management outcomes, restoration efforts, the scientific literature, and popular media coverage. Even so, SAV in Chesapeake Bay faces many historical and emerging challenges. The future of Chesapeake Bay is indicated by and contingent on the success of SAV. Its persistence will require continued action, coupled with new practices, to promote a healthy and sustainable ecosystem.

  6. Production and Field Planting of Vegetative Propagules for Restoration of Redhead Grass and Sago Pondweed in Chesapeake Bay

    Science.gov (United States)

    2009-08-01

    submerged aquatic vegetation (SAV) have been lost from shallow waters of Chesapeake Bay (Orth and Moore 1983) and other coastal ecosystems worldwide...a mixture of ambient estuarine water from the Choptank River (a tributary of Chesapeake Bay) and freshwater (tap) needed to maintain a salinity of 7...with a mixture of freshwater and ambient estuarine water (to maintain a salinity of 10) that was circulated through a closed- loop recirculation system

  7. Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM) in coastal surface waters of the Northwestern Mediterranean Sea (Bay of Marseilles, France)

    Science.gov (United States)

    Para, J.; Coble, P. G.; Charrière, B.; Tedetti, M.; Fontana, C.; Sempéré, R.

    2010-07-01

    Seawater samples were collected in surface waters (2 and 5 m depths) of the Bay of Marseilles (Northwestern Mediterranean Sea; 5°17'30'' E, 43°14'30'' N) during one year from November 2007 to December 2008 and studied for total organic carbon (TOC) as well as chromophoric dissolved organic matter (CDOM) optical properties (absorbance and fluorescence). The annual mean value of surface CDOM absorption coefficient at 350 nm [aCDOM(350)] was very low (0.10 ± 0.02 m-1) with in comparison to values usually found in coastal waters, and no significant seasonal trend in aCDOM(350) could be determined. By contrast, the spectral slope of CDOM absorption (SCDOM) was significantly higher (0.023 ± 0.003 nm-1) in summer than in fall and winter periods (0.017 ± 0.002 nm-1), reflecting either CDOM photobleaching or production in surface waters during stratified sunny periods. The CDOM fluorescence, assessed through excitation emission matrices (EEMs), was dominated by protein-like component (peak T; 1.30-21.94 QSU) and marine humic-like component (peak M; 0.55-5.82 QSU), while terrestrial humic-like fluorescence (peak C; 0.34-2.99 QSU) remained very low. This reflected a dominance of relatively fresh material from biological origin within the CDOM fluorescent pool. At the end of summer, surface CDOM fluorescence was very low and strongly blue shifted, reinforcing the hypothesis of CDOM photobleaching. Our results suggested that unusual Rhône River plume eastward intrusion events may reach Marseilles Bay within 2-3 days and induce local phytoplankton blooms and subsequent fluorescent CDOM production (peaks M and T) without adding terrestrial fluorescence signatures (peak C). Besides Rhône River plumes, mixing events of the entire water column injected humic (peaks C and M) CDOM from the bottom into the surface and thus appeared also as an important source of CDOM in surface waters of the Marseilles Bay. Therefore, the assessment of CDOM optical properties, within the

  8. The evolution of water property in the Mackenzie Bay polynya during Antarctic winter

    Science.gov (United States)

    Xu, Zhixin; Gao, Guoping; Xu, Jianping; Shi, Maochong

    2017-10-01

    Temperature and salinity profile data, collected by southern elephant seals equipped with autonomous CTD-Satellite Relay Data Loggers (CTD-SRDLs) during the Antarctic wintertime in 2011 and 2012, were used to study the evolution of water property and the resultant formation of the high density water in the Mackenzie Bay polynya (MBP) in front of the Amery Ice Shelf (AIS). In late March the upper 100-200 m layer is characterized by strong halocline and inversion thermocline. The mixed layer keeps deepening up to 250 m by mid-April with potential temperature remaining nearly the surface freezing point and sea surface salinity increasing from 34.00 to 34.21. From then on until mid-May, the whole water column stays isothermally at about -1.90℃ while the surface salinity increases by a further 0.23. Hereafter the temperature increases while salinity decreases along with the increasing depth both by 0.1 order of magnitude vertically. The upper ocean heat content ranging from 120.5 to 2.9 MJ m-2, heat flux with the values of 9.8-287.0 W m-2 loss and the sea ice growth rates of 4.3-11.7 cm d-1 were estimated by using simple 1-D heat and salt budget methods. The MBP exists throughout the whole Antarctic winter (March to October) due to the air-sea-ice interaction, with an average size of about 5.0×103 km2. It can be speculated that the decrease of the salinity of the upper ocean may occur after October each year. The recurring sea-ice production and the associated brine rejection process increase the salinity of the water column in the MBP progressively, resulting in, eventually, the formation of a large body of high density water.

  9. STUDY OF POLLUTANT DISTRIBUTION IN BENOA BAY USING NUMERICAL SIMULATION AND SATELLITE DATA

    Directory of Open Access Journals (Sweden)

    Komang Ardana

    2012-11-01

    Full Text Available Euthrofication that caused by nitrate and phosphate contamination and also sedimentation process is the mainproblem that took place in Benoa Bay Territorial water. The distribution of phosphate pollutant in Benoa bay territorialwater was modeled by numeric of Princeton Ocean model (POM. The input of this pollutant model were a tidal currentpattern, M2 tidal current residue, biological factor, physic and chemistry, that influenced pollutant concentration.Meanwhile, the sedimentation concentration was mapped with ALOS AVNIR-2 sensor image satellite and this image wasanalysed with statistic method (Linear Regression.The result of phosphate modeling concentration was 0.1 mg/1 to 0.0022 mg/1, where the concentration wascategorized very hazardous to the territorial water environment. Because the phosphate concentration in a pollutantresources was beyond the standard level of environmental quality, that was 0.015 mg/1 for fishery cultivation and alsotourism activity (Bali Governor Regulation No.8th 2007. While, the direction of the distribution was affected by currentpattern of movement, that was when the ebb level of high water moving into the bay and when the ebb to high tidemoving out of the bay.The result of statistic approaches with ALOS of AVNIR-2 censor can be used for mapping sedimentationdistribution advantages in Benoa Bay. The values were: R2 Band 1 is 0.3839, Band 2 is 0.6123 and Band 3 is 0.5468. Inthis methodology, the correlation was not significant, due to, the quantity of in-situ data was small and the time researchwas not at the same time with satellite data.

  10. Strain-induced shear instability in Liverpool Bay

    Science.gov (United States)

    Wihsgott, Juliane; Palmer, Matthew R.

    2013-04-01

    Liverpool Bay is a shallow subsection of the eastern Irish Sea with large tides (10 m), which drive strong tidal currents (1 ms-1). The Bay is heavily influenced by large freshwater inputs from several Welsh and English rivers that maintain a strong and persistent horizontal density gradient. This gradient interacts with the sheared tidal currents to strain freshwater over denser pelagic water on a semi-diurnal frequency. This Strain-Induced-Periodic-Stratification (SIPS) has important implications on vertical and horizontal mixing. The subtle interaction between stratification and turbulence in this complex environment is shown to be of critical importance to freshwater transport, and subsequently the fate of associated biogeochemical and pollutant pathways. Recent work identified an asymmetry of current ellipses due to SIPS that increases shear instability in the halocline with the potential to enhance diapycnal mixing. Here, we use data from a short, high intensity process study which reveals this mid-water mechanism maintains prolonged periods of sub-critical gradient Richardson number (Ri ≤ ¼) that suggests shear instability is likely. A time series of measurements from a microstructure profiler identifies the associated increase in turbulence is short lived and 'patchy' but sufficient to promote diapycnal mixing. The significance of this mixing process is further investigated by comparing our findings with long-term observations from the Liverpool Bay Coastal Observatory. We identify that the conditions for shear instability during SIPS are regularly met and suggest that this process contributes to the current underestimates of near coastal mixing observed in regional models. To assist our understanding of the observed processes and to test the current capability of turbulence 'closure schemes' we employ a one-dimensional numerical model to investigate the physical mechanisms driving diapycnal mixing in Liverpool Bay.

  11. Ferric Iron Precipitation in the Nagahama Bay, Satsuma Iwo-Jima Island, Kagoshima

    Science.gov (United States)

    Nagata, T.; Kiyokawa, S.; Ikehara, M.; Oguri, K.; Goto, S.; Ito, T.; Yamaguchi, K. E.; Ueshiba, T.

    2010-12-01

    Satsuma-Iwojima island is active volcanic island and 6 x 3 km in size, located 38km south of Kyushu island, Japan. The reddish brown water along the coast of the Iwo-dake volcano at the center of the island formed by neutralization through mixing of shallow hydrothermal fluid and seawater. The reddish brown water contains reddish ferrihydrite (Fe3+) that is derived from oxidation of Fe2+ from acidic hot spring (Shikaura and Tazaki, 2001). In the Nagahama Bay with its opening to the south, red-colored Fe-rich water is affected by tidal current, but sedimentation of the ferric hydroxide is confirmed to occur in the ocean bottom (Ninomiya and Kiyokawa, 2009). Here we focus other lines of evidence from long term observations and meteorological records as important factor to form thick iron rich sediments. Meteorological and stationary observations: We used weather record in the Satsuma Iwo-jima and cross-checked with stationary observations, which enabled us to observe color changes of the surface of Nagahama Bay. It was made clear that north wind condition in the Nagahama Bay resulted in changes of the color of its surface, from red to green, by intrusion of ocean water coming from outside. Long term temperature monitoring: The temperature of seawater in the Nagahama Bay fluctuated synchronically with the air temperature. But that of hot spring water rather remained constant regardless of the seasonal change. We observed that seawater temperature in the Nagahama Bay is low at high tide and high at low tide, and the rage of temperature change is maximum at the spring tide and minimum at the neap tide. In other words, the amount of discharge of hot spring and that of seawater inflow vary inversely. Core sample: In the Nagahama Bay, iron rich sediments that is more than 1 m thick were identified. The core sample shows lithology as following; upper part, 10-20cm thick, formed loose Fe-rich deposit, lower portion formed alteration of weakly consolidated Fe-rich orange

  12. Submarine groundwater discharge as an important nutrient source influencing nutrient structure in coastal water of Daya Bay, China

    Science.gov (United States)

    Wang, Xuejing; Li, Hailong; Zheng, Chunmiao; Yang, Jinzhong; Zhang, Yan; Zhang, Meng; Qi, Zhanhui; Xiao, Kai; Zhang, Xiaolang

    2018-03-01

    As an important nutrient source for coastal waters, submarine groundwater discharge (SGD) has long been largely ignored in Daya Bay, China. In this study, we estimate the fluxes of SGD and associated nutrients into this region using a 224Ra mass balance model and assess the contribution/importance of nutrients by SGD, benthic sediments, local rivers, and atmospheric deposition. The results of 224Ra mass balance show that the estimated SGD ranges from (2.76 ± 1.43) × 106 m3/d to (1.03 ± 0.53) × 107 m3/d with an average of (6.32 ± 2.42) × 106 m3/d, about 16 times the total discharge rate of local rivers. The nutrient loading from SGD is estimated to be (1.05-1.99) × 105 mol/d for NO3-N, (4.04-12.16) × 103 mol/d for DIP, and (3.54-11.35) × 105 mol/d for Si. Among these considered nutrient sources, we find that SGD is the primary source for Si and NO3-N, contributing 68% and 42% of all considered sources, respectively. The atmospheric NO3-N flux is comparable to that from SGD. The local rivers are the most important source for DIP, contributing 75% of all considered sources. SGD with high N:P ratio (NO3-N/DIP) of 37.0 delivers not only a large quantity of nutrients, but also changes nutrient structure in coastal water. Based on a DIP budget, primary productivity is evaluated to be 54-73 mg C/m2 d, in which SGD accounts for approximately 30% of total production. This study indicates that SGD is a key source of nutrients to coastal waters and may cause an obvious change of primary production and nutrient structure in Daya Bay.

  13. 77 FR 2972 - Thunder Bay Power Company, Thunder Bay Power, LLC, et al.

    Science.gov (United States)

    2012-01-20

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Thunder Bay Power Company, Thunder Bay Power, LLC, et al.; Notice of Application for Transfer of Licenses, and Soliciting Comments and Motions To Intervene Thunder Bay Power Company Project No. 2404-095 Thunder Bay Power, LLC Midwest Hydro, Inc...

  14. 77 FR 7025 - Safety Zones; America's Cup World Series, East Passage, Narragansett Bay, RI

    Science.gov (United States)

    2012-02-10

    ...-AA00 Safety Zones; America's Cup World Series, East Passage, Narragansett Bay, RI AGENCY: Coast Guard... the America's Cup World Series sailing vessel racing event. This safety zone is intended to safeguard...'s Cup-class races on the waters of the East Passage, Narragansett Bay, Rhode Island. Vessels will be...

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

    Science.gov (United States)

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

    2010-01-01

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

  16. Eutrophication influence on phytoplankton community composition in three bays on the eastern Adriatic coast

    Directory of Open Access Journals (Sweden)

    Mia Bužančić

    2016-10-01

    Full Text Available This study shows the influence of eutrophication pressure on the phytoplankton community structure, abundance and biodiversity in the investigated bays with different hydromorphological features. Šibenik Bay is a highly stratified estuary of the karstic river Krka; Kaštela Bay is a semi-enclosed coastal bay, which is influenced by the relatively small river Jadro; and Mali Ston Bay is located at the Neretva River estuary, the largest river on the eastern part of the Adriatic Sea. All of the areas are affected by urban pressure, which is reflected in the trophic status of the waters. The greatest anthropogenic influence was found in Kaštela Bay while the lowest influence was found in Mali Ston Bay. In this study, the highest biomass concentration and maximum abundance of phytoplankton were recorded at the stations under the strongest anthropogenic influence. Those stations show a dominance of abundance compared to the biomass and a dominance of opportunistic species, which is reflected in the lower biodiversity of phytoplankton community. Diatoms were the most represented group of the phytoplankton community in all three bays, followed by the dinoflagellates. Diatoms that were highlighted as significant for the difference between the bays were Skeletonema marinoi in Šibenik Bay, Leptocylindrus minimus in Kaštela Bay and the genus Chaetoceros spp. in Mali Ston Bay. Dinoflagellates were more abundant at the stations under the strongest anthropogenic influence, and most significant were Prorocentrum triestinum in Kaštela Bay and Gymnodinium spp. in Šibenik Bay and Mali Ston Bay.

  17. Influence of orographically steered winds on Mutsu Bay surface currents

    Science.gov (United States)

    Yamaguchi, Satoshi; Kawamura, Hiroshi

    2005-09-01

    Effects of spatially dependent sea surface wind field on currents in Mutsu Bay, which is located at the northern end of Japanese Honshu Island, are investigated using winds derived from synthetic aperture radar (SAR) images and a numerical model. A characteristic wind pattern over the bay was evidenced from analysis of 118 SAR images and coincided with in situ observations. Wind is topographically steered with easterly winds entering the bay through the terrestrial gap and stronger wind blowing over the central water toward its mouth. Nearshore winds are weaker due to terrestrial blockages. Using the Princeton Ocean Model, we investigated currents forced by the observed spatially dependent wind field. The predicted current pattern agrees well with available observations. For a uniform wind field of equal magnitude and average direction, the circulation pattern departs from observations demonstrating that vorticity input due to spatially dependent wind stress is essential in generation of the wind-driven current in Mutsu Bay.

  18. Residence times and nitrate transport in ground water discharging to streams in the Chesapeake Bay Watershed

    Science.gov (United States)

    Lindsey, Bruce D.; Phillips, Scott; Donnelly, Colleen A.; Speiran, Gary K.; Plummer, Niel; Bohlke, John Karl; Focazio, Michael J.; Burton, William C.; Busenberg, Eurybiades

    2003-01-01

    One of the major water-quality problems in the Chesapeake Bay is an overabundance of nutrients from the streams and rivers that discharge to the Bay. Some of these nutrients are from nonpoint sources such as atmospheric deposition, agricultural manure and fertilizer, and septic systems. The effects of efforts to control nonpoint sources, however, can be difficult to quantify because of the lag time between changes at the land surface and the response in the base-flow (ground water) component of streams. To help resource managers understand the lag time between implementation of management practices and subsequent response in the nutrient concentrations in the base-flow component of streamflow, a study of ground-water discharge, residence time, and nitrate transport in springs throughout the Chesapeake Bay Watershed and in four smaller watersheds in selected hydrogeomorphic regions (HGMRs) was conducted. The four watersheds were in the Coastal Plain Uplands, Piedmont crystalline, Valley and Ridge carbonate, and Valley and Ridge siliciclastic HGMRs.A study of springs to estimate an apparent age of the ground water was based on analyses for concentrations of chlorofluorocarbons in water samples collected from 48 springs in the Chesapeake Bay Watershed. Results of the analysis indicate that median age for all the samples was 10 years, with the 25th percentile having an age of 7 years and the 75th percentile having an age of 13 years. Although the number of samples collected in each HGMR was limited, there did not appear to be distinct differences in the ages between the HGMRs. The ranges were similar between the major HGMRs above the Fall Line (modern to about 50 years), with only two HGMRs of small geographic extent (Piedmont carbonate and Mesozoic Lowland) having ranges of modern to about 10 years. The median values of all the HGMRs ranged from 7 to 11 years. Not enough samples were collected in the Coastal Plain for comparison. Spring samples showed slightly younger

  19. Temporal variations of Cu in Jiaozhou Bay 1982-1986

    Science.gov (United States)

    Yang, Dongfang; Zhu, Sixi; Wang, Zhikang; Su, Chunhua; Wang, Qiang

    2017-12-01

    This paper analyzed the temporal variations of Cu in Jiaozhou Bay during 1982-1986. Results showed that Cu contents in study years were 0.15-5.31 μg L-1, 0.77-20.60 μg L-1, 0.11-4.00 μg L-1, 0.10-0.43 μg L-1 and 0.18-0.77 μg L-1, respectively. The Cu pollution level in this bay was moderate during 1982-1983, yet for temporal variations Cu contents in surface waters were showing decreasing trend. Cu contents in spring, summer and autumn were 0.11-20.60 μg L-1, 0.10-4.86 μg L-1 and 0.11-3.56 μg L-1, respectively. This bay was moderate pollution in spring in 1982-1983, while in other seasons in study years was still slight. These indicated that the temporal variations of Cu pollution in this bay should be taken in to account in decision-making of pollution control practice.

  20. EVALUATION OF TROPHIC STATUS OF AGRAKHAN BAY (THE NORTH CASPIAN SEA AS A PART OF ECOLOGICAL MONITORING OF SPECIALLY PROTECTED AREAS

    Directory of Open Access Journals (Sweden)

    A. A. Gadzhiev

    2013-01-01

    Full Text Available Abstract. Aim. Hydrochemical composition of waters of Agrakhan Bay (the North Caspian Sea, degree of pollution, structure and quantitative characteristics of phytoplankton, zooplankton and zoobenthos is given in the paper. Evaluation of a trophic status of the bay and seasonal trophodynamics are given as a result of study.Material and methods. The study is based on original materials from expeditions of 2012 (Autumn and 2013 (Spring and Summer in Agrakhan Bay. The complex materials are collected on stations with distance 3.5 km. Totally was made 16 marine stations, where samples of water, phytoplankton, zooplankton and benthos were taken.Results. Agrakhan Bay is eutrophic by level of dissolved oxygen and its BOD. However, the oxygen deficiency is not observed. concentration of oxygen is high almost in all seasons, that has a beneficial effect on hydrobionts. Seasonal dynamics indicates that Agrakhansky bay is oligotrophic within a year, but its trophic status increases to mesotrophic and even to hypertrophic in some periods. The northern part ща the bay is eutrophic. Difference in trophic levels of different parts of the bay is the result of significant differences in depth and area of water surface.Conclusions. Anthropogenic impact on Agrakhan Bay increases its trophic status. Seasonal trophic level of Agrakhan Gulf except natural processes depends on the "purity" of the Terek River sediments, which are the main source of biogenic elements. Typically, the absolute concentration of biogenic elements in Agrakhan Bay increases with the increase of eutrophication.

  1. Investigation on the distribution and fate of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in a sewage-impacted bay

    International Nuclear Information System (INIS)

    Wang, Shiliang; Wang, Hui; Zhao, Wei; Cao, Yuanxin; Wan, Yi

    2015-01-01

    The distribution and fate of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) were investigated in the water and sediment of Bohai Bay, China, during 2011–2013. A total of 360 water samples and 60 sediment samples were collected from 20 locations. The median concentrations of PFOS and PFOA were 4.8 and 12.15 ng/L in the water, and 2.65 and 0.62 ng/g-dry in the sediment, respectively. Significant enrichment were observed for PFOS and PFOA in water of sea surface microlayer. The concentrations of these two compounds showed an apparent gradient from nearshore to offshore stations. The correlation analysis and the distribution tendencies indicated that freshwater inflowing to the bay was the main source of PFOS and PFOA. The salinity of seawater and the total organic carbon (TOC) content of sediment heavily affected the spatial distribution and the partitioning of PFOS and PFOA in the sediment-water system. - Highlights: • We investigated the distribution and partitioning of PFOS and PFOA in Bohai Bay. • The PFOS and PFOA concentration showed a gradient from nearshore to offshore sites. • The PFOS and PFOA enriched significantly in the sea surface microlayer of water. • Inflowing freshwater was the main source of PFOS and PFOA in Bohai Bay. • Salinity and TOC deeply affected the distribution and partitioning of PFOS and PFOA. - The spatial and temporal distribution and the partitioning of perfluorooctane sulfonate and perfluorooctanoate were determined in the seawater-sediment system of Bohai Bay

  2. Influence of net freshwater supply on salinity in Florida Bay

    Science.gov (United States)

    Nuttle, William K.; Fourqurean, James W.; Cosby, Bernard J.; Zieman, Joseph C.; Robblee, Michael B.

    2000-01-01

    An annual water budget for Florida Bay, the large, seasonally hypersaline estuary in the Everglades National Park, was constructed using physically based models and long‐term (31 years) data on salinity, hydrology, and climate. Effects of seasonal and interannual variations of the net freshwater supply (runoff plus rainfall minus evaporation) on salinity variation within the bay were also examined. Particular attention was paid to the effects of runoff, which are the focus of ambitious plans to restore and conserve the Florida Bay ecosystem. From 1965 to 1995 the annual runoff from the Everglades into the bay was less than one tenth of the annual direct rainfall onto the bay, while estimated annual evaporation slightly exceeded annual rainfall. The average net freshwater supply to the bay over a year was thus approximately zero, and interannual variations in salinity appeared to be affected primarily by interannual fluctuations in rainfall. At the annual scale, runoff apparently had little effect on the bay as a whole during this period. On a seasonal basis, variations in rainfall, evaporation, and runoff were not in phase, and the net freshwater supply to the bay varied between positive and negative values, contributing to a strong seasonal pattern in salinity, especially in regions of the bay relatively isolated from exchanges with the Gulf of Mexico and Atlantic Ocean. Changes in runoff could have a greater effect on salinity in the bay if the seasonal patterns of rainfall and evaporation and the timing of the runoff are considered. One model was also used to simulate spatial and temporal patterns of salinity responses expected to result from changes in net freshwater supply. Simulations in which runoff was increased by a factor of 2 (but with no change in spatial pattern) indicated that increased runoff will lower salinity values in eastern Florida Bay, increase the variability of salinity in the South Region, but have little effect on salinity in the Central

  3. Temperature, salinity, and nutrients from near surface shallow water samples of Mamala Bay Project MB-9, Ecosystem Response Study, (1993-1994) on Oahu, Hawaii (NODC Accession 9900064)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water quality at 10 recreational beaches in Mamala Bay and in the nearshore ocean were monitored over a period of 12 months in 1993-1994 to determine the impact of...

  4. Potential sources of bacteriological pollution for two bays with marinas in Trinidad

    Directory of Open Access Journals (Sweden)

    Christine Ann Bullock

    2005-05-01

    Full Text Available Welcome Bay and Chaguaramas Bay in the northwest peninsula of Trinidad contain large marinas and smaller sections of bathing beaches.Bacteriological surveys were conducted at both bays to assess water quality and to determine potential sources of pollution.These surveys were conducted during the wet season of 1996 and the dry season of 1997.Eleven sample stations were established at Welcome Bay and 12 at Chaguaramas Bay.Freshwater samples were collected from rivers and drains within the survey area.Marine water samples were collected from marinas,bathing beaches and inshore and outer areas at both bays.Five water samples were collected from each sampling station during the wet season of 1996 and six during the dry season of 1997.The membrane filter technique was used to determine faecal coliform and Escherichia coli levels in all samples. There was a seasonal effect on water quality,with significantly higher faecal coliform levels in the wet season, when water quality was not in compliance with international standards.This represents a potential health risk in bathing areas.Water quality was better at the outer area of both bays.Water quality at the inner bay areas was most likely adversely affected by land-based sources of pollution identified in this study.These sources include three drains and two rivers,which discharged into the bays.Yachts were apparently not a source of sewage pollution:there was no significant relationship between yacht number and faecal coliform levels.Las bahías Welcome y Chaguaramas en la península noroeste de Trinidad tienen grandes marinas y secciones pequeñas de playas para bañistas.Se realizaron sondeos bacteriológicos en ambas bahías para determinar la calidad del agua y para señalar fuentes potenciales de contaminación.Estos sondeos fueron realizados durante la época lluviosa de 1996 y la seca de 1997.Once estaciones de muestreo se establecieron en Bahía Welcome y doce en Bahía Chaguaramas.Muestras de

  5. Using Seeds to Propagate and Restore Vallisneria americana Michaux (Wild Celery) in the Chesapeake Bay

    Science.gov (United States)

    2007-12-01

    the capacity of the plants to elongate so that the leaves can reach closer to the water surface to gather adequate light for photosynthesis . When...transplant eelgrass (Zostera marina L.) in Chesapeake Bay and the Virginia Coastal Bays, In Proc. Conf. Seagrass Restoration: Success, Failure, and

  6. Multielement determination in river-water of Sepetiba Bay tributaries (Brazil) by total reflection X-ray fluorescence using synchrotron radiation

    International Nuclear Information System (INIS)

    Costa, A.C.M.; Castro, C.R.F.; Lopes, R.T.; Anjos, M.J.; Rio de Janeiro State Univ.

    2006-01-01

    Trace elements were determined in the surface waters of tributaries of the Sepetiba Bay, Brazil (Piraque, Ita, Sao Francisco, Guarda, Guandu Mirim, Vala do Sangue and Engenho Novo rivers) by total reflection X-ray fluorescence using synchrotron radiation (SRTXRF). Eighteen trace elements could be determined in the dissolved and the suspended particulate phases: Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb. The elemental concentration values were compared to the values recommended by the Brazilian legislation. (author)

  7. The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay

    Directory of Open Access Journals (Sweden)

    I. D. Irby

    2018-05-01

    Full Text Available The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic–biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea level will increase estuarine circulation, reducing residence time in bottom waters and increasing stratification. As a result, oxygen concentrations in bottom waters are projected to increase, while oxygen concentrations at mid-depths (3 < DO < 5 mg L−1 will typically decrease. Changes in precipitation are projected to deliver higher winter and spring freshwater flow and nutrient loads, fueling increased primary production. Together, these multiple climate impacts will lower DO throughout the Chesapeake Bay and negatively impact progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load. However, this research also shows that the potential impacts of climate change will be significantly smaller than improvements in DO expected in response to the required nutrient reductions, especially at the anoxic and hypoxic levels. Overall, increased temperature exhibits the strongest control on the change in future DO concentrations, primarily due to decreased solubility, while sea level rise is expected to exert a small positive impact and increased winter river flow is anticipated to exert a small negative impact.

  8. Single-beam bathymetry data collected in 2015 from Grand Bay, Alabama-Mississippi

    Science.gov (United States)

    DeWitt, Nancy T.; Stalk, Chelsea A.; Smith, Christopher G.; Locker, Stanley D.; Fredericks, Jake J.; McCloskey, Terrence A.; Wheaton, Cathryn J.

    2017-12-01

    As part of the Sea-level and Storm Impacts on Estuarine Environments and Shorelines (SSIEES) project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted a single-beam bathymetry survey within the estuarine, open-bay, and tidal creek environments of Grand Bay, Alabama-Mississippi, from May to June 2015. The goal of the SSIEES project is to assess the physical controls of sediment and material exchange between wetlands and estuarine environments along the northern Gulf of Mexico, specifically Grand Bay, Alabama-Mississippi; Vermilion Bay, Louisiana; and, along the east coast, within Chincoteague Bay, Virginia-Maryland. The data described in this report provide baseline bathymetric information for future research investigating wetland-marsh evolution, sediment transport, erosion, recent and long-term geomorphic change, and can also support the modeling of changes in response to restoration and storm impacts. The survey area encompasses more than 40 square kilometers of Grand Bay’s waters.

  9. Colored dissolved organic matter in Tampa Bay, Florida

    Science.gov (United States)

    Chen, Z.; Hu, C.; Conmy, R.N.; Muller-Karger, F.; Swarzenski, P.

    2007-01-01

    Absorption and fluorescence of colored dissolved organic matter (CDOM) and concentrations of dissolved organic carbon (DOC), chlorophyll and total suspended solids in Tampa Bay and its adjacent rivers were examined in June and October of 2004. Except in Old Tampa Bay (OTB), the spatial distribution of CDOM showed a conservative relationship with salinity in June, 2004 (aCDOM(400) = − 0.19 × salinity + 6.78, R2 = 0.98, n = 17, salinity range = 1.1–32.5) with little variations in absorption spectral slope and fluorescence efficiency. This indicates that CDOM distribution was dominated by mixing. In October, 2004, CDOM distribution was nonconservative with an average absorption coefficient (aCDOM(400), ∼ 7.76 m-1) about seven times higher than that in June (∼ 1.11 m-1). The nonconservative behavior was caused largely by CDOM removal at intermediate salinities (e.g., aCDOM(400) removal > 15% at salinity ∼ 13.0), which likely resulted from photobleaching due to stronger stratification. The spatial and seasonal distributions of CDOM in Tampa Bay showed that the two largest rivers, the Alafia River (AR) and Hillsborough River (HR) were dominant CDOM sources to most of the bay. In OTB, however, CDOM showed distinctive differences: lower absorption coefficient, higher absorption spectral slopes, and lower ratios of CDOM absorption to DOC and higher fluorescence efficiency. These differences may have stemmed from (1) changes in CDOM composition by more intensive photobleaching due to the longer residence time of water mass in OTB; (2) other sources of CDOM than the HR/AR inputs, such as local creeks, streams, groundwater, and/or bottom re-suspension. Average CDOM absorption in Tampa Bay at 443 nm, aCDOM(443), was about five times higher in June and about ten times higher in October than phytoplankton pigment absorption, aph(443), indicating that blue light attenuation in the water column was dominated by CDOM rather than by phytoplankton absorption throughout the

  10. Assessment of Kerch Bay environmental pollution using neuroglial proteins of ground fish

    Directory of Open Access Journals (Sweden)

    H. V. Sukharenko

    2014-03-01

    Full Text Available The modern ecology situation in waters of the Kerch Strait requires assessment of disturbances in biotopes and monitoring of the degree of impact of industrial pollutants on ecosystem. Deposit of oil products after the 2007 year ships’ accidents might have considerable impact on the water biocenosis area. The investigation of cytoskeleton marker of astrocytes glial fibrillary acidic protein (GFAP in brain of the bullhead (Neogobius fluviatilis, which is the typical representative of the commercial ground fish of the Kerch Strait, has been carried out. The results of comparative analysis of GFAP content in the brain of fish from the Kerch Bay near-shore waters and fish from conditionally clear area of Vorskla river shows the reliable (2.18 times increasing of GFAP in the area of industrial pollution. Rising GFAP content indicates the astrogliosis development as a result of metabolic disturbances which can be induced by higher content of oil products in the near-bottom biotopes of the Kerch Bay. Increase in lipid peroxidation level was observed in the brain of fish from the Kerch Bay. The results provided with regard to violations of the state of astrocyte cytoskeleton and oxidative stress in the brain of bullhead from the Kerch Bay prove the sublethal biology effect of industrial pollutants in hydrobionts from this area. Results of this investigation also indicate the necessity of continuous ecology monitoring and comprehensive study of hydrobiont populations in the industrial regions and ecological disaster zones.

  11. Water Quality and Sedimentation Data of the Coastal Intensive Site Network (CISNet) Long Term Monitoring Sites in Kaneohe Bay, Oahu, Hawaii from 1998 to 2001 (NODC Accession 0001473)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A long term project to monitor water quality and sediment processes in Kaneohe Bay was initiated in November 1998 and continued through July 2001. Four primary sites...

  12. NASA-modified precipitation products to improve USEPA nonpoint source water quality modeling for the Chesapeake Bay.

    Science.gov (United States)

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The USEPA has estimated that over 20,000 water bodies within the United States do not meet water quality standards. One of the regulations in the Clean Water Act of 1972 requires states to monitor the total maximum daily load, or the amount of pollution that can be carried by a water body before it is determined to be "polluted," for any watershed in the United States (Copeland, 2005). In response to this mandate, the USEPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a decision support tool for assessing pollution and to guide the decision-making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program-Fortran (HSPF), computes continuous streamflow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events, especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA-modified/NOAA precipitation data. Using these data within HSPF, streamflow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better streamflow statistics and, potentially, in improved water quality assessment.

  13. Development of an integrated ecosystem model to determine effectiveness of potential watershed management projects on improving Old Tampa Bay

    Science.gov (United States)

    Edward T. Sherwood; Holly Greening; Lizanne Garcia; Kris Kaufman; Tony Janicki; Ray Pribble; Brett Cunningham; Steve Peene; Jim Fitzpatrick; Kellie Dixon; Mike Wessel

    2016-01-01

    The Tampa Bay estuary has undergone a remarkable ecosystem recovery since the 1980s despite continued population growth within the region. However during this time, the Old Tampa Bay (OTB) segment has lagged behind the rest of the Bay’s recovery relative to improvements in overall water quality and seagrass coverage. In 2011, the Tampa Bay Estuary Program, in...

  14. GIS-based health assessment of the marine ecosystem in Laizhou Bay, China.

    Science.gov (United States)

    Song, Debin; Gao, Zhiqiang; Zhang, Hua; Xu, Fuxiang; Zheng, Xiangyu; Ai, Jinquan; Hu, Xiaoke; Huang, Guopei; Zhang, Haibo

    2017-12-15

    According to 2014-2016 monitoring data, an assessment index system including water quality, depositional environment and ecosystem was built to evaluate the health statue of marine ecosystem in the Laizhou Bay using analytic hierarchy process (AHP) method. The results, spatialized in ArcGIS software, show: while the comprehensive ecological health index is 0.62, the ecological environmental quality in the Laizhou Bay is in a sub-healthy state; the unhealthy area is mainly concentrated in southwestern inshore region, and impacted by serious environmental problems, such as water eutrophication and heavy metal pollution; the northwestern and southeastern inshore regions are in a sub-healthy state, while the eastern inshore and northern areas are in the healthiest state. The land-based pollutants that discharge into the sea may be the leading factors that are causing ecological environment deterioration in the Laizhou Bay, and the reclamation work ongoing around the port has exacerbated the ecological risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. An Intrathermocline Eddy and a tropical cyclone in the Bay of Bengal

    Science.gov (United States)

    Gordon, Arnold L.; Shroyer, Emily; Murty, V. S. N.

    2017-04-01

    The Bay of Bengal, subjected to monsoonal forcing and tropical cyclones, displays a complex field of ocean eddies. On 5 December 2013 a sub-surface vortex or Intrathermocline Eddy (ITE) composed of water characteristic of the Andaman Sea was observed within the thermocline of the western Bay of Bengal. We propose that the ITE was the product of Tropical Cyclone Lehar interaction on 27 November 2013 with a westward propagating surface eddy from the eastern Bay of Bengal. While Lehar’s interaction with the ocean initially removes heat from the upper layers of the eddy, air-sea flux is limited as the deeper portions of the eddy was subducted into the stratified thermocline, inhibiting further interaction with the atmosphere. The ITE core from 30 to 150 m is thus isolated from local air-sea fluxes by strong stratification at the mixed layer base, and its periphery is stable to shear instability, suggestive of longevity and the ability to carry water far distances with minimal modification.

  16. Bird surveys at McKinley Bay and Hutchison Bay, Northwest Territories, in 1991

    Energy Technology Data Exchange (ETDEWEB)

    Cornish, B J; Dickson, D L; Dickson, H L

    1992-03-01

    McKinley Bay is a shallow protected bay along the eastern Beaufort Sea coast which provides an important habitat for diving ducks. Since 1979, the bay has been the site of a winter harbor and support base for oil and gas exploraton in the Beaufort Sea. Aerial surveys for bird abundance and distribution were conducted in August 1991 as a continuation of long-term monitoring of birds in McKinley Bay and Hutchison Bay, a nearby area used as a control. The main objectives of the 1991 surveys were to expand the set of baseline data on natural annual fluctuations in diving duck numbers, and to determine if numbers of diving ducks had changed since the initial 1981-85 surveys. On the day with the best survey conditions, the population of diving ducks at McKinley bay was estimated at ca 32,000, significantly more than 1981-85. At Hutchison Bay, there were an estimated 11,000 ducks. As in previous years, large numbers of diving ducks were observed off Atkinson Point at the northwest corner of McKinley Bay, at the south end of the bay, and in the northeast corner near a long spit. Most divers in Hutchison Bay were at the west side. Diving ducks, primarily Oldsquaw and scoter, were the most abundant bird group in the study area. Observed distribution patterns of birds are discussed with reference to habitat preferences. 16 refs., 7 figs., 30 tabs.

  17. Bottle data collected for chemical analysis along the coastal waters of Hawai'i as part of the Windward Community College Heeia Stream and Kaneohe Bay Water Quality Assessment Project from May 22, 2004 to March 19, 2005 (NODC Accession 0002449)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Measurements of water quality parameters were taken by Windward Community College faculty and students at eight sites in the Heeia Stream and adjacent Kaneohe Bay...

  18. Gulf of Mexico Integrated Science - Tampa Bay Study - Characterization of Tidal Wetlands

    Science.gov (United States)

    McIvor, Carole

    2005-01-01

    Tidal wetlands in Tampa Bay, Florida, consist of mangrove forests and salt marshes. Wetlands buffer storm surges, provide fish and wildlife habitat, and enhance water quality through the removal of water-borne nutrients and contaminants. Substantial areas of both mangroves and salt marshes have been lost to agricultural, residential, and industrial development in this urban estuary. Wetlands researchers are characterizing the biological components of tidal wetlands and examining the physical factors such as salinity, tidal flushing, and sediment deposition that control the composition of tidal wetland habitats. Wetlands restoration is a priority of resource managers in Tampa Bay. Baseline studies such as these are needed for successful restoration planning and evaluation.

  19. Circulation and geostrophic transport in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.P.; Murty, V.S.N.

    Utilising the hydrographic data collected during the early northeast monsoon of 1983 and southwest monsoon of 1984, the circulation of waters of the Bay of Bengal and the associated volume transport have been studied in the upper 1000 m...

  20. Review of wastewater problems and wastewater-management planning in the San Francisco Bay region, California

    Science.gov (United States)

    Hines, Walter G.

    1973-01-01

    The San Francisco Bay region has suffered adverse environmental effects related to the discharge of municipal-, industrial-, and agricultural- wastewater and storm-water runoff. Specific pollutional properties of theses discharges are not well understood in all cases although the toxic materials and aquatic-plant nutrients (biostimulants) found in municipal and industrial waterwater are considered to be a major cause of regional water-quality problems. Other water-quality problems in the region are commonly attributed to pesticides found in agricultural wastewater and potentially pathogenic bacteria in municipal-wastewater discharges and in storm-water runoff. The geographical distribution and magnitude of wastewater discharges in the bay region, particularly those from municipalities and industries, is largely a function of population, economic growth, and urban development. As might be expected, the total volume of wastewater has increased in a trend paralleling this growth and development. More significant, perhaps, is the fact that the total volume parameters such as BOD (biochemical oxygen demand), biostimulant concentrations, and toxicity, has increased despite large expenditures on new and improved municipal- and industrial-wastewater-treatment plants. Also, pollutant loadings from other major source, such as agriculture and storm-water runoff, have increased. At the time of writing (1972), many Federal, State, regional, and local agencies are engaged in a comprehensive wastewater-management-planning effort for the entire bay region. Initial objectives of this planning effort are: (1) the consolidation and coordination of loosely integrated wastewater-management facilities and (2) the elimination of wastewater discharges to ecologically sensitive areas, such as fresh-water streams and shallow extremities of San Francisco Bay. There has been some investigation of potential long-range wastewater-management alternatives based upon disposal in deep water in the

  1. Nitrous oxide in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.; Jayakumar, D; Nair, M.; DileepKumar, M.; George, M.D

    Extensive observations on nitrous oxide (N@d2@@O) in the atmosphere and waters of the western Bay of Bengal during March-April 1991 yield surface saturations and atmospheric fluxes ranging from 89.3 to 213.9% (mean 125.2%), and from 0.10 to 10...

  2. Monitoring Water Quality at Lake Merritt, Oakland, CA Following Improvements to the Tidal Channel to the San Francisco Bay

    Science.gov (United States)

    Bracho, H.; Martinez, J.; Johnson, M.; Turrey, A.; Avila, M.; Medina, S.; Rubio, E.; Ahumada, E.; Nguyen, S.; Guzman, Y.

    2014-12-01

    Elliot Ahumada, Esosa Oghogho, Samantha Nguyen, Humberto Bracho, Diego Quintero, Ashanti Johnson and Kevin Cuff Lake Merritt is a tidal lagoon in the center of Oakland, California, just east of Downtown. Water quality at Lake Merritt has been a major concern for community members and researchers for many years (Pham 200X). Results of past research lead to recommendations to lengthen a channel that connects Lake Merritt with the San Francisco Bay to improve water flow and quality. In 2012 the City of Oakland responded to these recommendations by initiating the creation of a 230-meter long channel. In conducting our research we use a water quality index that takes into account measurements of pH, temperature, water hardness (dissolved solids), ammonia, salinity, dissolved oxygen, and nitrate. Newly collected data is then compared with that collected by Pham using comparable parameters to assess the impact of recent changes at the Lake on its overall water quality. In addition, we measured the abundance of aquatic species at four different sites within the Lake. Preliminary results suggest that an increase in the abundance of fish and improved overall water quality have resulted from channel extension at Lake Merritt.

  3. Atmospheric deposition having been one of the major source of Pb in Jiaozhou Bay

    Science.gov (United States)

    Yang, Dongfang; Miao, Zhenqing; Zhang, Xiaolong; Wang, Qi; Li, Haixia

    2018-03-01

    Many marine bays have been polluted by Pb due to the rapid development of industry, and identifying the major source of Pb is essential to pollution control. This paper analyzed the distribution and pollution source of Pb in Jiaozhou Bay in 1988. Results showed that Pb contents in surface waters in Jiaozhou Bay in April, July and October 1988 were 5.52-24.61 μg L‑1, 7.66-38.62 μg L‑1 and 6.89-19.30 μg L‑1, respectively. The major Pb sources in this bay were atmospheric deposition, and marine current, whose source strengths were 19.30-24.61μg L‑1 and 38.62 μg L‑1, respectively. Atmospheric deposition had been one of the major Pb sources in Jiaozhou Bay, and the source strengths were stable and strong. The pollution level of Pb in this bay in 1988 was moderate to heavy, and the source control measurements were necessary.

  4. Nutrient load estimates for Manila Bay, Philippines using population data

    Science.gov (United States)

    Sotto, Lara Patricia A.; Beusen, Arthur H. W.; Villanoy, Cesar L.; Bouwman, Lex F.; Jacinto, Gil S.

    2015-06-01

    A major source of nutrient load to periodically hypoxic Manila Bay is the urban nutrient waste water flow from humans and industries to surface water. In Manila alone, the population density is as high as 19,137 people/km2. A model based on a global point source model by Morée et al. (2013) was used to estimate the contribution of the population to nitrogen and phosphorus emissions which was then used in a water transport model to estimate the nitrogen (N) and phosphorus (P) loads to Manila Bay. Seven scenarios for 2050 were tested, with varying degrees and amounts for extent of sewage treatment, and population growth rates were also included. In scenario 1, the sewage connection and treatment remains the same as 2010; in scenario 2, sewage connection is improved but the treatment is the same; in scenario 3, the sewage connection as well as treatment is improved (70% tertiary); and in scenario 4, a more realistic situation of 70% primary treatment achieved with 100% connection to pipes is tested. Scenarios 5, 6, and 7 have the same parameters as 1, 2, and 3 respectively, but with the population growth rate per province reduced to half of what was used in 1, 2, and 3. In all scenarios, a significant increase in N and P loads was observed (varying from 27% to 469% relative to 2010 values). This was found even in scenario 3 where 70% of the waste water undergoes tertiary treatment which removes 80% N and 90% P. However, the lowest increase in N and P load into the bay was achieved in scenarios 5 to 7 where population growth rate is reduced to half of 2010 values. The results suggest that aside from improving sewage treatment, the continued increase of the human population in Manila at current growth rates will be an important determinant of N and P load into Manila Bay.

  5. Inhomogeneity of optical turbulence over False Bay (South Africa)

    Science.gov (United States)

    Ullwer, Carmen; Sprung, Detlev; van Eijk, Alexander M. J.; Gunter, Willi; Stein, Karin

    2017-09-01

    Atmospheric turbulence impacts on the propagation of electro-optical radiation. Typical manifestations of optical turbulence are scintillation (intensity fluctuations), beam wander and (for laser systems) reduction of beam quality. For longer propagation channels, it is important to characterize the vertical and horizontal distribution (inhomogeneity) of the optical turbulence. In the framework of the First European South African Transmission ExpeRiment (FESTER) optical turbulence was measured between June 2015 and February 2016 on a 2 km over-water link over False Bay. The link ran from the Institute of Maritime Technology (IMT) in Simons Town to the lighthouse at Roman Rock Island. Three Boundary layer scintillometers (BLS900) allowed assessing the vertical distribution of optical turbulence at three different heights between 5 and 12 m above the water surface. The expected decrease of Cn2 with height is not always found. These results are analyzed in terms of the meteorological scenarios, and a comparison is made with a fourth optical link providing optical turbulence data over a 8.7 km path from IMT to Kalk Bay, roughly 36° to the north of the three 2 km paths. The results are related to the inhomogeneous meteorological conditions over the Bay as assessed with the numerical weather prediction tool, the Weather Forecast and Research model WRF.

  6. Account of the littoral diatoms from Langebaan, Saldanha bay, Cape province, South Africa

    CSIR Research Space (South Africa)

    Giffen, MH

    1975-01-01

    Full Text Available collec ted in a small bay near the holiday resort of Langebaan (long. 18,02 E, lat. 33,05 5) on the eastern shore of Saldanha Bay. Saldanha Bay is situated on the western coast of South Africa some 110 km north of Cape Town, and forms a long narrow... per annum about 79% during April to September (i.e. winter rainfall). The region can therefore be regarded as semi-desert. The salinity of the sea water at Langebaan was 35 0/00. The average temperature range of the air in summer is from 16.5? C...

  7. Eureka Littoral Cell CRSMP Humboldt Bay Mean Monthly Maximum Water Elevation 2011

    Data.gov (United States)

    California Natural Resource Agency — The Humboldt Bay Shoreline Assessment and LiDAR Analysis was conducted by field mapping the entire shoreline and assigning an unique segment identifier based on a...

  8. Eureka Littoral Cell CRSMP Humboldt Bay Mean Monthly Maximum Water Elevation 2011

    Data.gov (United States)

    California Department of Resources — The Humboldt Bay Shoreline Assessment and LiDAR Analysis was conducted by field mapping the entire shoreline and assigning an unique segment identifier based on a...

  9. THE RESPONSE OF MONTEREY BAY TO THE GREAT TOHOKU EARTHQUAKE OF 2011

    Directory of Open Access Journals (Sweden)

    D. Carroll

    2011-01-01

    Full Text Available The response of Monterey Bay to the Great Tohoku earthquake of 2011 is examined in this study. From a practical standpoint, although the resulting tsunami did not cause any damage to the open harbors at Monterey and Moss Landing, it caused extensive damage to boats and infrastructure in Santa Cruz Harbor, which is closed to surrounding waters. From a scientific standpoint, the observed and predicted amplitudes of the tsunami at 1 km from the source were 21.3 and 22.5 m based on the primary arrival from one DART bottom pressure recorder located 986 km ENE of the epicenter. The predicted and observed travel times for the tsunami to reach Monterey Bay agreed within 3%. The predicted and observed periods of the tsunami-generated wave before it entered the bay yielded periods that approached 2 hours. Once the tsunami entered Monterey Bay it was transformed into a seiche with a primary period of 36-37 minutes, corresponding to quarter-wave resonance within the bay. Finally, from a predictive standpoint, major tsunamis that enter the bay from the northwest, as in the present case, are the ones most likely to cause damage to Santa Cruz harbor.

  10. Nutrient load estimates for Manila Bay, Philippines using population data

    NARCIS (Netherlands)

    Sotto, Lara Patricia A; Beusen, Arthur H W; Villanoy, Cesar L.; Bouwman, Lex F.; Jacinto, Gil S.

    2015-01-01

    A major source of nutrient load to periodically hypoxic Manila Bay is the urban nutrient waste water flow from humans and industries to surface water. In Manila alone, the population density is as high as 19,137 people/km2. A model based on a global point source model by Morée et al. (2013) was used

  11. Preponderance of a few diatom species among the highly diverse microphytoplankton assemblages in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Paul, J.T.; Ramaiah, N.; Gauns, M.; Fernandes, V.

    The microphytoplankton assemblages were studied from water samples collected at eight discrete depths in the top 120 m at five central [open ocean] and four western [shelf/slope region] locations in the Bay of Bengal. The Bay is a low...

  12. Multi-band algorithms for the estimation of chlorophyll concentration in the Chesapeake Bay

    KAUST Repository

    Gilerson, Alexander

    2015-10-14

    Standard blue-green ratio algorithms do not usually work well in turbid productive waters because of the contamination of the blue and green bands by CDOM absorption and scattering by non-algal particles. One of the alternative approaches is based on the two- or three band ratio algorithms in the red/NIR part of the spectrum, which require 665, 708, 753 nm bands (or similar) and which work well in various waters all over the world. The critical 708 nm band for these algorithms is not available on MODIS and VIIRS sensors, which limits applications of this approach. We report on another approach where a combination of the 745nm band with blue-green-red bands was the basis for the new algorithms. A multi-band algorithm which includes ratios Rrs(488)/Rrs(551)and Rrs(671)/Rrs(745) and two band algorithm based on Rrs671/Rrs745 ratio were developed with the main focus on the Chesapeake Bay (USA) waters. These algorithms were tested on the specially developed synthetic datasets, well representing the main relationships between water parameters in the Bay taken from the NASA NOMAD database and available literature, on the field data collected by our group during a 2013 campaign in the Bay, as well as NASA SeaBASS data from the other group and on matchups between satellite imagery and water parameters measured by the Chesapeake Bay program. Our results demonstrate that the coefficient of determination can be as high as R2 > 0.90 for the new algorithms in comparison with R2 = 0.6 for the standard OC3V algorithm on the same field dataset. Substantial improvement was also achieved by applying a similar approach (inclusion of Rrs(667)/Rrs(753) ratio) for MODIS matchups. Results for VIIRS are not yet conclusive. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  13. Lagrangian circulation of the North Atlantic Central Water over the abyssal plain and continental slopes of the Bay of Biscay: description of selected mesoscale features

    Directory of Open Access Journals (Sweden)

    Alain Serpette

    2006-06-01

    Full Text Available Between 1994 and 2001, several experiments (ARCANE, SEFOS, INTERAFOS were conducted to directly measure the general and mesoscale Lagrangian circulations over the Bay of Biscay abyssal plain and slopes. Two levels (~100 m and ~450 m were selected to cover the North Atlantic Central Water range. Two types of Lagrangian instruments, drogued surface drifters tracked by satellite (Surdrift and acoustically tracked subsurface floats (Rafos and Marvor, were used. Overall, more than 36 instrument-years were collected in the Bay of Biscay region (43-49°N, 01-12°W. The weak general circulation in the Bay of Biscay is seen to be highly influenced by the occurrence of several mesoscale coherent features, notably slope currents and eddies, and these affect the exchanges between the abyssal plain and the slopes. The objective of this paper is to depict some specific examples of the observed mesoscale field. Selected float trajectories are shown and used to discuss observations of slope currents and of both anticyclonic and cyclonic eddies. Slope currents exhibit alternation of poleward and equatorward directions, depending on both the period and the geographic area considered. Although the generation process of mesoscale eddies is difficult to observe unambiguously from Lagrangian instruments, eddies are nevertheless ubiquitous over the abyssal plain. Some characteristics of the observed cyclonic and anticyclonic eddies are presented. Smaller anticyclones, localised over the outer shelf and interpreted in terms of ajustment of slope water intrusions, are also depicted.

  14. Is drinking water a risk factor for endemic cryptosporidiosis? A case-control study in the immunocompetent general population of the San Francisco Bay Area

    Directory of Open Access Journals (Sweden)

    Nadle Joelle

    2003-03-01

    Full Text Available Abstract Background Cryptosporidiosis, caused by Cryptosporidium, is an enteric illness that has received much attention as an infection of immunocompromised persons as well as in community outbreaks (frequently waterborne. There are, however, no studies of the risk factors for sporadic community-acquired cryptosporidiosis in the immunocompetent US population. We undertook a case-control study in the San Francisco Bay Area as part of a national study sponsored by the Centers for Disease Control and Prevention to ascertain the major routes of transmission for endemic cryptosporidiosis, with an emphasis on evaluating risk from drinking water. Methods Cases were recruited from a population-based, active surveillance system and age-matched controls were recruited using sequential random-digit dialing. Cases (n = 26 and controls (n = 62 were interviewed by telephone using a standardized questionnaire that included information about the following exposures: drinking water, recreational water, food items, travel, animal contact, and person-to-person fecal contact, and (for adults sexual practices. Results In multivariate conditional logistic regression analyses no significant association with drinking water was detected. The major risk factor for cryptosporidiosis in the San Francisco Bay Area was travel to another country (matched odds ratio [95% confidence interval]: 24.1 [2.6, 220]. Conclusion The results of this study do not support the hypothesis that drinking water is an independent risk factor for cryptosporidiosis among the immunocompetent population. These findings should be used to design larger studies of endemic cryptosporidiosis to elucidate the precise mechanisms of transmission, whether waterborne or other.

  15. 76 FR 44531 - Safety Zone; Fourth Annual Chillounge Night St. Petersburg Fireworks Display, Tampa Bay, St...

    Science.gov (United States)

    2011-07-26

    ...-AA00 Safety Zone; Fourth Annual Chillounge Night St. Petersburg Fireworks Display, Tampa Bay, St... proposes to establish a temporary safety zone on the waters of Tampa Bay in St. Petersburg, Florida during the Fourth Annual Chillounge Night St. Petersburg Fireworks Display on Saturday, November 19, 2011...

  16. 76 FR 68098 - Safety Zone; Fourth Annual Chillounge Night St. Petersburg Fireworks Display, Tampa Bay, St...

    Science.gov (United States)

    2011-11-03

    ...-AA00 Safety Zone; Fourth Annual Chillounge Night St. Petersburg Fireworks Display, Tampa Bay, St... Guard is establishing a temporary safety zone on the waters of Tampa Bay in St. Petersburg, Florida during the Fourth Annual Chillounge Night St. Petersburg Fireworks Display on Saturday, November 19, 2011...

  17. The Impact of a Barrier Island Loss on Extreme Events in the Tampa Bay

    Directory of Open Access Journals (Sweden)

    Marius eUlm

    2016-04-01

    Full Text Available Barrier islands characterize up to an eighth of the global coastlines. They buffer the mainland coastal areas from storm surge and wave energy from the open ocean. Changes in their shape or disappearance due to erosion may lead to an increased impact of sea level extremes on the mainland. A barrier island threatened by erosion is Egmont Key which is located in the mouth of the Tampa Bay estuary at the west-central coast of Florida.In this sensitivity study we investigate the impact a loss of Egmont Key would have on storm surge water levels and wind waves along the coastline of Tampa Bay. We first simulate still water levels in a control run over the years 1948-2010 using present-day bathymetry and then in a scenario run covering the same period with identical boundary conditions but with Egmont Key removed from the bathymetry. Return water levels are assessed for the control and the scenario runs using the Peak-over-threshold method along the entire Tampa Bay coastline. Egmont Key is found to have a significant influence on the return water levels in the Bay, especially in the northern, furthest inland parts where water levels associated with the 100-year return period increase between 5 cm and 15 cm.Additionally, wind wave simulations considering all 99.5th percentile threshold exceedances in the years 1980-2013 were conducted with the same control and scenario bathymetries. Assessing changes in return levels of significant wave heights due to the loss of Egmont Key revealed an increase of significant wave heights around today's location of the island.

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

    Directory of Open Access Journals (Sweden)

    Mariya W Smith

    2015-10-01

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

  19. Impact of the river Liffey discharge on nutrient and chlorophyll concentrations in the Liffey estuary and Dublin Bay (Irish Sea)

    Science.gov (United States)

    O'Higgins, T. G.; Wilson, J. G.

    2005-08-01

    Temperature, salinity, nutrients (total oxidised nitrogen (TON), ammonium (NH 4) and orthophosphate (PO 4)) and chlorophyll a were monitored in the Liffey estuary and Dublin Bay from June 2000 to June 2003. Four groups of sites were defined comprising the upper estuary (Gp. I), the outer estuary (Gp. III) with a small set (Gp. II) of sites between Groups I and III heavily influenced by the sewage treatment works outflow, and the Bay proper (Gp. IV). Riverine inputs of TON and PO 4 were calculated at an average of 826 t N y -1 and 31 t P y -1, respectively, and were largely controlled by flow rate. The sewage treatment works were identified as a major source of PO 4 and NH 4 to the system. Mixing in the upper estuary of nutrient limited saline waters with hypernutrified river water regularly (i.e. annually) produced relatively high concentrations of chlorophyll a (>10 mg chl a m -3), and also sporadic blooms with extremely high chlorophyll a values (max. 121.6 mg chl a m -3). These latter phytoplankton blooms occurred in high salinity waters and were due to mixing of nutrient limited saline waters and nutrient rich river waters. The mean annual flux of phytoplankton carbon from the river Liffey was calculated at 23.5 t C y -1, of which half was accumulated or remineralised in the estuary and did not enter the Bay. In the Bay proper (Gp. IV) summer nutrient concentrations dropped below detection limits, and chlorophyll a concentrations followed the classic pattern with a spring bloom maximum of 5.5 mg chl a m -3. This pattern in nutrients and chlorophyll a came from the advection of waters into the Bay from an offshore source. Overall while there was considerable evidence for eutrophication in the estuary, the bay itself showed little biological response to nutrient loading.

  20. 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 ...

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

    Science.gov (United States)

    Porterfield, George

    1980-01-01

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

  2. Spatial and temporal distribution of two diazotrophic bacteria in the Chesapeake Bay.

    Science.gov (United States)

    Short, Steven M; Jenkins, Bethany D; Zehr, Jonathan P

    2004-04-01

    The aim of this study was to initiate autecological studies on uncultivated natural populations of diazotrophic bacteria by examining the distribution of specific diazotrophs in the Chesapeake Bay. By use of quantitative PCR, the abundance of two nifH sequences (907h22 and 912h4) was quantified in water samples collected along a transect from the head to the mouth of the Chesapeake Bay during cruises in April and October 2001 and 2002. Standard curves for the quantitative PCR assays demonstrated that the relationship between gene copies and cycle threshold was linear and highly reproducible from 1 to 10(7) gene copies. The maximum number of 907h22 gene copies detected was approximately 140 ml(-1) and the maximum number of 912h4 gene copies detected was approximately 340 ml(-1). Sequence 912h4 was most abundant at the mouth of the Chesapeake Bay, and in general, its abundance increased with increasing salinity, with the highest abundances observed in April 2002. Overall, the 907h22 phylotype was most abundant at the mid-bay station. Additionally, 907h22 was most abundant in the April samples from the mid-bay and mouth of the Chesapeake Bay. Despite the fact that the Chesapeake Bay is rarely nitrogen limited, our results show that individual nitrogen-fixing bacteria have distinct nonrandom spatial and seasonal distributions in the Chesapeake Bay and are either distributed by specific physical processes or adapted to different environmental niches.

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

    NARCIS (Netherlands)

    Van Der Putten, N.; Verbruggen, C.

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

  4. NASA-Modified Precipitation Products to Improve EPA Nonpoint Source Water Quality Modeling for the Chesapeake Bay

    Science.gov (United States)

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The Environmental Protection Agency (EPA) has estimated that over 20,000 water bodies within the United States do not meet water quality standards. Ninety percent of the impairments are typically caused by nonpoint sources. One of the regulations in the Clean Water Act of 1972 requires States to monitor the Total Maximum Daily Load (TMDL), or the amount of pollution that can be carried by a water body before it is determined to be "polluted", for any watershed in the U.S.. In response to this mandate, the EPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a Decision Support Tool (DST) for assessing pollution and to guide the decision making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program -- Fortran (HSPF), computes daily stream flow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA modified/NOAA precipitation data. Using these data within HSPF, stream flow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better stream flow statistics and, ultimately, in improved water quality assessment.

  5. 78 FR 5717 - Safety Zone; Military Ocean Terminal Concord Safety Zone, Suisun Bay, Military Ocean Terminal...

    Science.gov (United States)

    2013-01-28

    ...-AA00 Safety Zone; Military Ocean Terminal Concord Safety Zone, Suisun Bay, Military Ocean Terminal... Guard is establishing a safety zone in the navigable waters of Suisun Bay near Military Ocean Terminal Concord, CA in support of military onload and offload operations. This safety zone is established to...

  6. Understanding and analyzing the hydro-sedimentary processes in the Bay of Toulon. Contribution for modelling the dispersion of radionuclides

    International Nuclear Information System (INIS)

    Dufresne, Christiane

    2014-01-01

    This doctoral research aims to enhance knowledge of the hydro-sedimentary processes in the Bay of Toulon and to represent these processes through a post accidental managing tool, developed to simulate the dispersion of radionuclides. This work is based on a multidisciplinary strategy, using numerical modelling and in situ measurements to study the complex problem of contaminants in the marine environment. Hydrodynamic of the Bay and water mass exchanges through the channel have been studied. Results are highly linked to the atmospheric conditions and the water exchange times of the Little Bay range from two to six days, depending on wind conditions. Recorded data in the Las and Eygoutier Rivers led to the description and the estimation of the catchment yields to the Bay, poorly studied before. With one ton of particulate matter annually discharged by the Las River, the Little Bay seems to be a sedimentation area. In case of accidental release of radionuclides, this area appears to be a trapping zone. (author)

  7. Physico-chemical characterization of surface waters of the west coast of Algeria: Bay of Mostaganem and Cheliff estuary

    Directory of Open Access Journals (Sweden)

    Fatima Kies

    2014-12-01

    Full Text Available A follow-up in 2013 of the indicators of pollution (temperature, hydrogen potential, salinity, dissolved oxygen, ammonium, nitrites, nitrates, orthophosphates, ortho silicates, biological oxygen demand, chemical oxygen demand, suspended solids in surface water was performed, in order to estimate the physicochemical quality of the west coast of Algeria. The results obtained revealed the existence of a water contamination by domestic and industrial waste water conveyed to the north by the Cheliff River for discharge into the Bay of Mostaganem, marked by significant space-time variations. In January (24 mg / l, the values of nitrates recorded west of the mouth of Cheliff exceed norms. Ammonium records strong concentrations in January (1.2 mg NH4+/ l and in February (0.8 mg /l. Nitrites such lagging of high contents in January (NO2- 0.99 mg / l and February (NO2- 0.59 mg /l, respectively. The ortho phosphates post a maximum concentration in January (6.6mg PO43-/ l. In addition, the organic matter rate measured in surface water is maximum during periods of flooding especially in January (7.51 mg / l and lowest in the exceptionally dry season in August (2.19 mg / l.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  10. Atmospheric deposition of organochlorine contaminants to Galveston Bay, Texas

    Science.gov (United States)

    Park, June-Soo; Wade, Terry L.; Sweet, Stephen

    Atmospheric monitoring of PCBs and chlorinated pesticides (e.g., HCHs, chlordanes, and DDTs) in Galveston Bay was conducted at Seabrook, Texas. Air and wet deposition samples were collected from 2 February 1995 and continued through 6 August 1996. Vapor total PCB ( tPCB) concentrations in air ranged from 0.21 to 4.78 ng m -3 with a dominance of tri-chlorinated PCBs. Dissolved tPCBs in rain ranged from 0.08 to 3.34 ng l -1, with tetra-chlorinated PCBs predominating. The predominant isomers found in air and rain were α- and γ-HCH, α- and γ-chlordanes, 4,4'-DDT, and dieldrin. The concentrations of PCBs and pesticides in the air and rain revealed no clear seasonal trend. Elevated levels of PCBs in the air occurred when temperatures were high and wind came from urban and industrialized areas (S, SW, NW, and W of the site). Concentrations of HCHs were elevated in April, May, and October, perhaps due to local and/or regional applications of γ-HCH (lindane). Other pesticides showed no notable temporal variation. When winds originated from the Gulf of Mexico (southeasterly), lower concentrations of organochlorines were detected in the air. The direct deposition rate (wet+dry) of PCBs to Galveston Bay (6.40 μg m -2 yr -1) was significantly higher than that of pesticides by a factor of 5-10. The net flux from gas exchange estimated for PCBs was from Galveston Bay water to the atmosphere (78 μg m -2 yr -1). Gas exchange of PCBs from bay water to the atmosphere was the dominant flux.

  11. Large-Scale Submerged Aquatic Vegetation Restoration in Chesapeake Bay: Status Report, 2003-2006

    Science.gov (United States)

    2008-06-01

    seed injector designed by VIMS, which does not require a gel matrix, has been tested in Spider Crab Bay in Virginia’s Coastal Bays (Figures 13 and 14...seagrasses, contributing to their loss. Additionally, waters landward of restrictive breakwaters tend to be warmer ( blue and red thermometers) than those...marina), (2) wild celery (V. americana), (3) sago pondweed (S. pectinata), and (4) redhead grass (P. perfoliatus). Molecular and cultivation

  12. Identification of High Potential Bays for HABs Occurrence in Peninsular Malysia Using Palsar Remote Sensing Data

    Science.gov (United States)

    Pour, A. B.; Hashim, M.

    2016-09-01

    Increasing frequency, intensity, and geographic distribution of Harmful algal blooms (HABs) poses a serious threat to the coastal fish/shellfish aquaculture and fisheries in Malaysian bays. Rising in sea level, shoreline erosion, stresses on fisheries, population pressure, interference of land-use and lack of institutional capabilities for integrated management make major challenges. Recent investigations and satellite observations indicate HABs originated from specific coast that have favourable geographic, geomorphic and coastal geology conditions to bring the green macro algae from the coast offshore. Therefore, the identification of high HABs frequented bays using remote sensing and geology investigations in Malaysian waters is required to reduce future challenges in this unique case. This research implemented comprehensive geomorphic and coastal geology investigations combined with remote sensing digital image processing approach to identify Malaysian bays frequented with HABs occurrence in Malaysian waters territory. The landscape and geomorphological features of the Malaysian bays were constructed from the Phased Array type L-band Synthetic Aperture Radar (PALSAR) remote sensing satellite data combined with field observations and surveying. The samples for laboratory analysis were collected from the sediment stations with different distance across shorelines features and watersheds of the Johor Bahru estuary. This research identified that semi-enclosed bays such as Kuala Lumpur and Johor Bahru bays with connection to estuaries have high potential to be frequented with HABs occurrence.

  13. IDENTIFICATION OF HIGH POTENTIAL BAYS FOR HABs OCCURRENCE IN PENINSULAR MALYSIA USING PALSAR REMOTE SENSING DATA

    Directory of Open Access Journals (Sweden)

    A. B. Pour

    2016-09-01

    Full Text Available Increasing frequency, intensity, and geographic distribution of Harmful algal blooms (HABs poses a serious threat to the coastal fish/shellfish aquaculture and fisheries in Malaysian bays. Rising in sea level, shoreline erosion, stresses on fisheries, population pressure, interference of land-use and lack of institutional capabilities for integrated management make major challenges. Recent investigations and satellite observations indicate HABs originated from specific coast that have favourable geographic, geomorphic and coastal geology conditions to bring the green macro algae from the coast offshore. Therefore, the identification of high HABs frequented bays using remote sensing and geology investigations in Malaysian waters is required to reduce future challenges in this unique case. This research implemented comprehensive geomorphic and coastal geology investigations combined with remote sensing digital image processing approach to identify Malaysian bays frequented with HABs occurrence in Malaysian waters territory. The landscape and geomorphological features of the Malaysian bays were constructed from the Phased Array type L-band Synthetic Aperture Radar (PALSAR remote sensing satellite data combined with field observations and surveying. The samples for laboratory analysis were collected from the sediment stations with different distance across shorelines features and watersheds of the Johor Bahru estuary. This research identified that semi-enclosed bays such as Kuala Lumpur and Johor Bahru bays with connection to estuaries have high potential to be frequented with HABs occurrence.

  14. Water quality assessment in the Nha Trang Bay (Vietnam) by using in-situ and remotely sensed data

    NARCIS (Netherlands)

    Phan Minh Thu, T.; Schaepman, M.E.; Leemans, R.; Nguyen Tac An, A.; Tong Phuoc Hoang Son, S.; Ngo Manh Tien, T.; Phan Thanh Bac, B.

    2008-01-01

    The Nha Trang Bay (Vietnam) is an international marine protected area with significant economic, natural and recreational values. Considerable economic development is expected in particularly for tourism, navigation and aquaculture. However, in recent years the environmental quality of the Bay has

  15. Estimating the chlorophyll content in the waters of Guanabara Bay from the LANDSAT multispectral scanning digital data

    Science.gov (United States)

    Dejesusparada, N. (Principal Investigator); Bentancurt, J. J. V.; Herz, B. R.; Molion, L. B.

    1980-01-01

    Detection of water quality in Guanabara Bay using multispectral scanning digital data taken from LANDSAT satellites was examined. To test these processes, an empirical (statistical) approach was choosen to observe the degree of relationship between LANDSAT data and the in situ data taken simultaneously. The linear and nonlinear regression analyses were taken from among those developed by INPE in 1978. Results indicate that the major regression was in the number six MSS band, atmospheric effects, which indicated a correction coefficient of 0.99 and an average error of 6.59 micrograms liter. This error was similar to that obtained in the laboratory. The chlorophyll content was between 0 and 100 micrograms/liter, as taken from the MSS of LANDSAT.

  16. 75 FR 15611 - Safety Zone; United Portuguese SES Centennial Festa, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2010-03-30

    ...-AA00 Safety Zone; United Portuguese SES Centennial Festa, San Diego Bay, San Diego, CA AGENCY: Coast... navigable waters of the San Diego Bay in support of the United Portuguese SES Centennial Festa. This... Centennial Festa, which will include a fireworks presentation originating from a tug and barge combination in...

  17. 75 FR 19248 - Subject: Safety Zone; Sea World Summer Nights Fireworks, Mission Bay, San Diego, CA

    Science.gov (United States)

    2010-04-14

    ... can better evaluate its effects on them and participate in the rulemaking process. Small businesses...-AA00 Subject: Safety Zone; Sea World Summer Nights Fireworks, Mission Bay, San Diego, CA AGENCY: Coast... navigable waters of Mission Bay in support of the Sea World Summer Nights Fireworks. This safety zone is...

  18. MANAGEMENT OF LOBSTER FISHERY WITH EAFM APPROACH IN PALABUHANRATU BAY

    Directory of Open Access Journals (Sweden)

    Katarina Hesty Rombe

    2018-06-01

    Full Text Available This research was conducted in the Palabuhanratu Bay-Sukabumi in March 2016. The purpose of this study is to diagnose the Palabuhanratu Lobster Fishery using factors of Ecosystem Approach to Fisheries Management (EAFM. Water sampling was conducted at two lobster fishing ground. Measuring and weighing morphology lobster were conducted in collectors’s house. The results of this study showed that Palabuhanratu bay water quality was still within tolerable limits for live lobster. Panulirus homarus  is the most widely lobster caught below the size of a decent catch, reaching 2528.9 Kg. CPUE of lobster was declining which indicates a decline in the stock of lobster. The income of fishermen were still very far from the average wage and stakeholder participation was still lacking in the management of the lobster fishery. Keywords: EAFM factors, lobster, palabuhanratu

  19. Seasonal distribution and abundance of cetaceans within French waters- Part II: The Bay of Biscay and the English Channel

    Science.gov (United States)

    Laran, Sophie; Authier, Matthieu; Blanck, Aurélie; Doremus, Ghislain; Falchetto, Hélène; Monestiez, Pascal; Pettex, Emeline; Stephan, Eric; Van Canneyt, Olivier; Ridoux, Vincent

    2017-07-01

    From the Habitat Directive to the recent Marine Strategy Framework Directive, the conservation status of cetaceans in European water has been of concern for over two decades. In this study, a seasonal comparison of the abundance and distribution of cetaceans was carried out in two contrasted regions of the Eastern North Atlantic, the Bay of Biscay and the English Channel. Estimates were obtained in the two sub-regions (375,000 km²) from large aerial surveys conducted in the winter (November 2011 to February 2012) and in the summer (May to August 2012). The most abundant species encountered in the Channel, the harbour porpoise, displayed strong seasonal variations in its distribution but a stable abundance (18,000 individuals, CV=30%). In the Bay of Biscay, abundance and distribution patterns of common / striped dolphins varied from 285,000 individuals (95% CI: 174,000-481,000) in the winter, preferentially distributed close to the shelf break, to 494,000 individuals (95% CI: 342,000-719,000) distributed beyond the shelf break in summer. Baleen whales also exhibited an increase of their density in summer. Seasonal abundances of bottlenose dolphins were quite stable, with a large number of 'pelagic' encounters offshore in winter. No significant seasonal difference was estimated for pilot whales and sperm whale. These surveys provided baseline estimates to inform policies to be developed, or for existing conservation instruments such as the Habitats Directive. In addition, our results supported the hypothesis of a shift in the summer distributions of some species such as harbour porpoise and minke whale in European waters.

  20. Trace metal associations in the water column of South San Francisco Bay, California

    Science.gov (United States)

    Kuwabara, J.S.; Chang, Cecily C.Y.; Cloern, J.E.; Fries, T.L.; Davis, J.A.; Luoma, S.N.

    1989-01-01

    Spatial distributions of copper (Cu), zinc (Zn) and cadmium (Cd) were followed along a longitudinal gradient of dissolved organic carbon (DOC) in South San Francisco Bay (herein referred to as the South Bay). Dissolved Cu, Zn and Cd concentrations ranged from 24 to 66 nM, from 20 to 107 nM and from 1??2 to 4??7 nM, respectively, in samples collected on five dates beginning with the spring phytoplankton bloom and continuing through summer,1985. Dissolved Cu and Zn concentrations varied indirectly with salinity and directly with DOC concentration which ranged from 2??1 to 4??1 mg l-1. Available thermodynamic data strongly support the hypothesis that Cu speciation may be dominated by association with dissolved organic matter. Analogous control of Zn speciation by organic complexation was, however, not indicated in our computations. Computed free ion activity estimates for Cu, Zn and Cd were of the order of 10-10, 10-8 and 10-10 M, respectively. The availability of these metals may be among the factors regulating the growth of certain phytoplankton species within this region of the estuary. In contrast to dissolved Cu, dissolved Cd was directly related to the concentration of suspended particulate matter, suggesting a source of dissolved Cd coincident with elevated particle concentrations in the South Bay (e.g. runoff and solute desorption). Consistent with work in other estuaries, partitioning of all three trace metals onto suspended particulates was negatively correlated with salinity and positively correlated with increases in particulate organic carbon associated with the phytoplankton bloom. These results for the South Bay indicate that sorption processes influence dissolved concentrations of these trace metals, the degree of this influence varies among metals, and processes controlling metal distribution in this estuary appear to be more element-specific than spatially- or temporally-specific. ?? 1989.

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

    Science.gov (United States)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  3. Maturation, fecundity, and intertidal spawning of Pacific sand lance in the northern Gulf of Alaska

    Science.gov (United States)

    Robards, Martin D.; Piatt, John F.; Rose, G.A.

    1999-01-01

    Pacific sand lance Ammodytes hexapterus in Kachemak Bay, Alaska, showed no sexual dimorphism in length-to-weight (gonad-free) ratio or length-at-age relationship. Most matured in their second year, males earlier in the season than females, but females (31%) attained a higher gonadosomatic index than males (21%). Sand lance spawned intertidally once each year in late September and October on fine gravel or sandy beaches soon after the seasonal peak in water temperatures. Sand lance in Cook Inlet and Prince William Sound displayed similar maturation schedules. Schools were dominated 2: 1 by males as they approached the intertidal zone at a site where spawning has taken place for decades. Sand lance spawned vigorously in dense formations, leaving scoured pits in beach sediments. Fecundity of females (93–199 mm) was proportional to length, ranging from 1468 to 16 081 ova per female. About half of the overall spawning school fecundity was derived from age group 1 females (55% of the school by number). Spawned eggs were 1·02 mm in diameter, demersal, slightly adhesive, and deposited in the intertidal just below the waterline. Sand lance embryos developed over 67 days through periods of intertidal exposure and sub-freezing air temperatures.

  4. Ecosystem responses to long-term nutrient management in an urban estuary: Tampa Bay, Florida, USA

    Science.gov (United States)

    Greening, H.; Janicki, A.; Sherwood, E. T.; Pribble, R.; Johansson, J. O. R.

    2014-12-01

    In subtropical Tampa Bay, Florida, USA, we evaluated restoration trajectories before and after nutrient management strategies were implemented using long-term trends in nutrient loading, water quality, primary production, and seagrass extent. Following citizen demands for action, reduction in wastewater nutrient loading of approximately 90% in the late 1970s lowered external total nitrogen (TN) loading by more than 50% within three years. Continuing nutrient management actions from public and private sectors were associated with a steadily declining TN load rate and with concomitant reduction in chlorophyll-a concentrations and ambient nutrient concentrations since the mid-1980s, despite an increase of more than 1 M people living within the Tampa Bay metropolitan area. Water quality (chlorophyll-a concentration, water clarity as indicated by Secchi disk depth, total nitrogen concentration and dissolved oxygen) and seagrass coverage are approaching conditions observed in the 1950s, before the large increases in human population in the watershed. Following recovery from an extreme weather event in 1997-1998, water clarity increased significantly and seagrass is expanding at a rate significantly different than before the event, suggesting a feedback mechanism as observed in other systems. Key elements supporting the nutrient management strategy and concomitant ecosystem recovery in Tampa Bay include: 1) active community involvement, including agreement about quantifiable restoration goals; 2) regulatory and voluntary reduction in nutrient loadings from point, atmospheric, and nonpoint sources; 3) long-term water quality and seagrass extent monitoring; and 4) a commitment from public and private sectors to work together to attain restoration goals. A shift from a turbid, phytoplankton-based system to a clear water, seagrass-based system that began in the 1980s following comprehensive nutrient loading reductions has resulted in a present-day Tampa Bay which looks and

  5. 33 CFR 110.194a - Mobile Bay, Ala., and Mississippi Sound, Miss.

    Science.gov (United States)

    2010-07-01

    ... Sound, Miss. 110.194a Section 110.194a Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Mississippi Sound, Miss. (a) The anchorage grounds. (1) The waters of lower Mobile Bay, near Cedar Point... south by latitude 30°20′00″, and on the west by longitude 88°06′00″. (2) The waters of Mississippi Sound...

  6. Willingness to Pay Survey for Chesapeake Bay Total Maximum Daily Load

    Science.gov (United States)

    A stated preference survey to collect data on households’ use of Chesapeake Bay and its watershed, and of their preferences for a variety of water quality improvements likely to follow from pollution reduction programs.

  7. Correlation and Fishers’ Perception in Selected Sites in Laguna de Bay, Luzon Island, Philippines

    Directory of Open Access Journals (Sweden)

    Arthur J. Lagbas

    2017-01-01

    Full Text Available White goby (Glossogobius giuris Hamilton 1822 is an omnivorous, native fish species which can be found in Laguna de Bay and its tributaries, and in other bodies of water in the Philippines. Deteriorating water quality, unsustainable fishing practices, aquaculture and predation by introduced invasive species are threatening the population of white goby and other native fish species in Laguna de Bay. This study was conducted to correlate select physico-chemical parameters of lake water and zooplankton abundance, and to assess white goby population based on fishers’ perception. Water samples were collected in three sites in June, September and December 2014. Twenty one zooplankton species belonging to 12 families were identified. The most abundant and frequently encountered zooplankton species is Eurytemora affinis Poppe 1880. Zooplanktons were most abundant in June and lowest in September. Key informant interviews with local fishers revealed that white goby population was abundant in April to August while catch report showed that fish catch is abundant in June and least during December. The fish abundance in April to June could be attributed to high productivity especially in summer season. The fishers perceived that the population of white goby was declining mainly due to water pollution, aquaculture, and predation by invasive alien species. A multi-stakeholder sustainable watershed management should be adapted to improve the water quality and extinction of native fish species in Laguna de Bay.

  8. 75 FR 8297 - Tongass National Forest, Thorne Bay Ranger District, Thorne Bay, AK

    Science.gov (United States)

    2010-02-24

    ..., Thorne Bay, AK AGENCY: Forest Service, USDA. ACTION: Cancellation of Notice of intent to prepare an... Roberts, Zone Planner, Thorne Bay Ranger District, Tongass National Forest, P.O. Box 19001, Thorne Bay, AK 99919, telephone: 907-828-3250. SUPPLEMENTARY INFORMATION: The 47,007-acre Kosciusko Project Area is...

  9. 77 FR 44140 - Drawbridge Operation Regulation; Sturgeon Bay Ship Canal, Sturgeon Bay, WI

    Science.gov (United States)

    2012-07-27

    ... Maple-Oregon Bridges so vehicular traffic congestion would not develop on downtown Sturgeon Bay streets... movement of vehicular traffic in Sturgeon Bay. The Sturgeon Bay Ship Canal is approximately 8.6 miles long... significant increase in vehicular and vessel traffic during the peak tourist and navigation season between...

  10. Seasonal Variation of Colored Dissolved Organic Matter in Barataria Bay, Louisiana, Using Combined Landsat and Field Data

    Directory of Open Access Journals (Sweden)

    Ishan Joshi

    2015-09-01

    Full Text Available Coastal bays, such as Barataria Bay, are important transition zones between the terrigenous and marine environments that are also optically complex due to elevated amounts of particulate and dissolved constituents. Monthly field data collected over a period of 15 months in 2010 and 2011 in Barataria Bay were used to develop an empirical band ratio algorithm for the Landsat-5 TM that showed a good correlation with the Colored Dissolved Organic Matter (CDOM absorption coefficient at 355 nm (ag355 (R2 = 0.74. Landsat-derived CDOM maps generally captured the major details of CDOM distribution and seasonal influences, suggesting the potential use of Landsat imagery to monitor biogeochemistry in coastal water environments. An investigation of the seasonal variation in ag355 conducted using Landsat-derived ag355 as well as field data suggested the strong influence of seasonality in the different regions of the bay with the marine end members (lower bay experiencing generally low but highly variable ag355 and the freshwater end members (upper bay experiencing high ag355 with low variability. Barataria Bay experienced a significant increase in ag355 during the freshwater release at the Davis Pond Freshwater Diversion (DPFD following the Deep Water Horizon oil spill in 2010 and following the Mississippi River (MR flood conditions in 2011, resulting in a weak linkage to salinity in comparison to the other seasons. Tree based statistical analysis showed the influence of high river flow conditions, high- and low-pressure systems that appeared to control ag355 by ~28%, 29% and 43% of the time duration over the study period at the marine end member just outside the bay. An analysis of CDOM variability in 2010 revealed the strong influence of the MR in controlling CDOM abundance in the lower bay during the high flow conditions, while strong winds associated with cold fronts significantly increase CDOM abundance in the upper bay, thus revealing the important

  11. Study of dissolved oxygen content in the Eastern Bosporus Strait (Peter the Great Bay, Sea of Japan)

    Science.gov (United States)

    Grigoryeva, N. I.

    2017-09-01

    Seasonal changes in the dissolved oxygen (DO) content in water were analyzed based on long-term observations (2006-2013) in the Eastern Bosporus Strait (Peter the Great Bay, Sea of Japan). It was found that the monthly average DO concentrations at the bottom of the strait were significantly lower in summer than the average annual long-term data. The minimum DO contents were recorded during four months, from July to October. It was shown that the DO content in water depended on changes in current directions in the strait: lower DO contents resulted from hypoxic water inflow, mostly from Amur Bay.

  12. Extensive Chaetoceros curvisetus bloom in relation to water quality in Port Blair Bay, Andaman Islands.

    Science.gov (United States)

    Begum, Mehmuna; Sahu, Biraja Kumar; Das, Apurba Kumar; Vinithkumar, Nambali Valsalan; Kirubagaran, Ramalingam

    2015-05-01

    Blooming of diatom species Chaetoceros curvisetus (Cleve, 1889) was observed in Junglighat Bay and Haddo Harbour of Port Blair Bay of Andaman and Nicobar Islands during June 2010. Physico-chemical parameters, nutrient concentrations and phytoplankton composition data collected from five stations during 2010 were classified as bloom area (BA) and non-bloom area (NBA) and compared. Elevated values of dissolved oxygen were recorded in the BA, and it significantly varied (p NBA. Among the nutrient parameters studied, nitrate concentration indicated significant variation in BA and NBA (p NBA, indicating its utilization. In Junglighat Bay, the C. curvisetus species constituted 93.4 and 69.2% composition of total phytoplankton population during day 1 and day 2, respectively. The bloom forming stations separated out from the non-bloom forming station in non-parametric multidimensional scaling (nMDS) ordinations; cluster analysis powered by SIMPROF test also grouped the stations as BA and NBA.

  13. 33 CFR 334.300 - Hampton Roads and Willoughby Bay, Norfolk Naval Base, naval restricted area, Norfolk, Virginia.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Hampton Roads and Willoughby Bay, Norfolk Naval Base, naval restricted area, Norfolk, Virginia. 334.300 Section 334.300 Navigation and... RESTRICTED AREA REGULATIONS § 334.300 Hampton Roads and Willoughby Bay, Norfolk Naval Base, naval restricted...

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

    Science.gov (United States)

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

    2013-09-01

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

  15. Oceanography of Glacier Bay, Alaska: Implications for biological patterns in a glacial fjord estuary

    Science.gov (United States)

    Etherington, L.L.; Hooge, P.N.; Hooge, Elizabeth Ross; Hill, D.F.

    2007-01-01

    Alaska, U.S.A, is one of the few remaining locations in the world that has fjords that contain temperate idewater glaciers. Studying such estuarine systems provides vital information on how deglaciation affects oceanographic onditions of fjords and surrounding coastal waters. The oceanographic system of Glacier Bay, Alaska, is of particular interest ue to the rapid deglaciation of the Bay and the resulting changes in the estuarine environment, the relatively high oncentrations of marine mammals, seabirds, fishes, and invertebrates, and the Bay’s status as a national park, where ommercial fisheries are being phased out. We describe the first comprehensive broad-scale analysis of physical and iological oceanographic conditions within Glacier Bay based on CTD measurements at 24 stations from 1993 to 2002. easonal patterns of near-surface salinity, temperature, stratification, turbidity, and euphotic depth suggest that freshwater nput was highest in summer, emphasizing the critical role of glacier and snowmelt to this system. Strong and persistent tratification of surface waters driven by freshwater input occurred from spring through fall. After accounting for seasonal nd spatial variation, several of the external physical factors (i.e., air temperature, precipitation, day length) explained a large mount of variation in the physical properties of the surface waters. Spatial patterns of phytoplankton biomass varied hroughout the year and were related to stratification levels, euphotic depth, and day length. We observed hydrographic atterns indicative of strong competing forces influencing water column stability within Glacier Bay: high levels of freshwater ischarge promoted stratification in the upper fjord, while strong tidal currents over the Bay’s shallow entrance sill enhanced ertical mixing. Where these two processes met in the central deep basins there were optimal conditions of intermediate tratification, higher light levels, and potential nutrient renewal

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2002-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Joel Becira

    2006-06-01

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

  19. Population dynamics of the yellowstripe scad (Selaroides leptolepis Cuvier, 1833) and Indian mackerel (Rastrelliger kanagurta Cuvier, 1816) in the Wondama Bay Water, Indonesia

    Science.gov (United States)

    Sala, R.; Bawole, R.; Runtuboi, F.; Mudjirahayu; Wopi, I. A.; Budisetiawan, J.; Irwanto

    2018-03-01

    The Wondama Bay water is located within the Cendrawasih Bay National Park and is potential for fishery resources, including pelagic fish such as yellowstripe scad (Selaroides leptolepis Cuvier, 1833) and Indian mackerel (Rastrelliger kanagurta Cuvier, 1816). Yet, information about the population dynamics of these species in the region is unknown until today. Meanwhile, the fishing activities have been quite intensive and include the dominant catches over the last ten years by traditional fishermen fishing using liftnets. Therefore, this study aims to determine some of specific characteristics of the population dynamics and fish utilization status of scad and mackerel in the waters of the Wondama Bay. Data used in this study were taken from direct observation of catch of liftnet fishery. The data then were analysed by using FISAT II to estimate the growth parameters, mortality rates, and yield per recruitment. The results showed that yellowstripe scad has the positive allometric growth, while Indian mackerel followed isometric growth. Models of fish growth were L(t) = 22 (1-e-3.0(t-0.05)) for yellowstripe scad and L(t) = 27.8 (1-e-4.0(t-0.04)) for Indian mackerel. The natural mortality (M) of 4.19 year-1, fishing mortality (F) of 5.01 year-1, and total mortality (Z) of 9.20 year-1 were for yellowstripe scad, and M of 4.74 year-1, F of 2.52 year-1 and Z of 7.26 year-1 were for Indian mackerel. Based on the mortality rates, estimated exploitation rate for the yellowatripe scad was 54 % and the Indian mackerel was 35 %. To increase the production of catch without increasing fishing effort (fishing mortality) can be done by increasing the size of fish caught or the Lc/L∞ should be greater than 0.5.

  20. Tidal Mixing Box Submodel for Tampa Bay: Calibration of Tidal Exchange Flows with the Parameter Estimation Tool (PEST)

    Science.gov (United States)

    In the mid-1990s the Tampa Bay Estuary Program proposed a nutrient reduction strategy focused on improving water clarity to promote seagrass expansion within Tampa Bay. A System Dynamics Model is being developed to evaluate spatially and temporally explicit impacts of nutrient r...

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  2. Basin-scale seasonal changes in marine free-living bacterioplankton community in the Ofunato Bay

    KAUST Repository

    Reza, Md. Shaheed

    2018-04-26

    The Ofunato Bay in the northeastern Pacific Ocean area of Japan possesses the highest biodiversity of marine organisms in the world and has attracted much attention due to its economic and environmental importance. We report here a shotgun metagenomic analysis of the year-round variation in free-living bacterioplankton collected across the entire length of the bay. Phylogenetic differences among spring, summer, autumn and winter bacterioplankton suggested that members of Proteobacteria tended to decrease at high water temperatures and increase at low temperatures. It was revealed that Candidatus Pelagibacter varied seasonally, reaching as much as 60% of all sequences at the genus level in the surface waters during winter. This increase was more evident in the deeper waters, where they reached up to 75%. The relative abundance of Planktomarina also rose during winter and fell during summer. A significant component of the winter bacterioplankton community was Archaea (mainly represented by Nitrosopumilus), as their relative abundance was very low during spring and summer but high during winter. In contrast, Actinobacteria and Cyanobacteria appeared to be higher in abundance during high-temperature periods. It was also revealed that Bacteroidetes constituted a significant component of the summer bacterioplankton community, being the second largest bacterial phylum detected in the Ofunato Bay. Its members, notably Polaribacter and Flavobacterium, were found to be high in abundance during spring and summer, particularly in the surface waters. Principal component analysis and hierarchal clustering analyses showed that the bacterial communities in the Ofunato Bay changed seasonally, likely caused by the levels of organic matter, which would be deeply mixed with surface runoff in the winter.

  3. Occurrence and fate of micropollutants in the Vidy Bay of Lake Geneva, Switzerland. Part II: micropollutant removal between wastewater and raw drinking water.

    Science.gov (United States)

    Morasch, Barbara; Bonvin, Florence; Reiser, Hans; Grandjean, Dominique; de Alencastro, Luiz Felippe; Perazzolo, Chiara; Chèvre, Nathalie; Kohn, Tamar

    2010-08-01

    The occurrence and removal of 58 pharmaceuticals, endocrine disruptors, corrosion inhibitors, biocides, and pesticides, were assessed in the wastewater treatment plant (WWTP) of the city of Lausanne, Switzerland, as well as in the effluent-receiving water body, the Vidy Bay of Lake Geneva. An analytical screening method to simultaneously measure all of the 58 micropollutants was developed based on ultra performance liquid chromatography coupled to a tandem mass spectrometer (UPLC-MS/MS). The selection of pharmaceuticals was primarily based on a prioritization study, which designated them as environmentally relevant for the Lake Geneva region. Except for the endocrine disruptor 17alpha-ethinylestradiol, all substances were detected in 24-h composite samples of wastewater entering the WWTP or in the treated effluent. Of these compounds, 40% were also detected in raw drinking water, pumped from the lake 3 km downstream of the WWTP. The contributions of dilution and degradation to micropollutant elimination between the WWTP outlet and the raw drinking water intake were established in different model scenarios using hypothetical residence times of the wastewater in Vidy Bay of 1, 4, or 90 d. Concentration decrease due to processes other than dilution was observed for diclofenac, beta-blockers, several antibiotics, corrosion inhibitors, and pesticides. Measured environmental concentrations (MECs) of pharmaceuticals were compared to the predicted environmental concentrations (PECs) determined in the prioritization study and agreed within one order of magnitude, but MECs were typically greater than the corresponding PECs. Predicted no-effect concentrations of the analgesic paracetamol, and the two antibiotics ciprofloxacin and sulfamethoxazole, were exceeded in raw drinking water samples and therefore present a potential risk to the ecosystem. Copyright 2010 SETAC

  4. 78 FR 46813 - Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay, WI

    Science.gov (United States)

    2013-08-02

    ...-AA00 Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay, WI AGENCY: Coast Guard, DHS. ACTION.... This temporary safety zone will restrict vessels from a portion of Sturgeon Bay due to a fireworks... hazards associated with the fireworks display. DATES: This rule is effective from 8 p.m. until 10 p.m. on...

  5. Upwelling features near Sri Lanka in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    ShreeRam, P.; Rao, L.V.G.

    , the southwest monsoon in summer and the northeast monsoon in winter. The wind stress associated with these winds cause mass drift of oceanic waters leading to upwelling and downwelling. The upwelling features in the Bay of Bengal with a special mention about...

  6. 77 FR 38488 - Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY

    Science.gov (United States)

    2012-06-28

    ... 1625-AA00 Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY... restrict vessels from a portion of the St. Lawrence River during the Alexandria Bay Chamber of Commerce... of proposed rulemaking (NPRM) entitled Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence...

  7. Tracing water movement in Mumbai harbor bay using naturally occurring "2"2"4Ra and "2"2"3Ra as tracer

    International Nuclear Information System (INIS)

    Yadav, V.B.; Sartandel, S.J.; Jha, S.K.; Tripathi, R.M.

    2017-01-01

    Measurement of short lived radium isotopes "2"2"4Ra and "2"2"3Ra in seawater samples collected from Mumbai Harbor Bay was carried out using MnO_2 based in-situ pre-concentration technique coupled with coincidence counting. Longitudinal variation of "2"2"4Ra and "2"2"3Ra was found in the range 17.74 - 98.66 dpm/100L and 0.56 - 2.26 dpm/100L respectively. Higher value of radium isotopes was found near shore sampling points where reused seawater and surface water from land intrudes in creek. A decreasing pattern was observed in the creek as we move to offshore locations. Lower activity ratio in offshore locations indicates the flow of water towards open sea. (author)

  8. Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM) in coastal surface waters of the Northwestern Mediterranean Sea (Bay of Marseilles, France)

    OpenAIRE

    J. Para; P. G. Coble; B. Charrière; M. Tedetti; C. Fontana; R. Sempéré

    2010-01-01

    Seawater samples were collected in surface waters (2 and 5 m depths) of the Bay of Marseilles (Northwestern Mediterranean Sea; 5°17′30′′ E, 43°14′30′′ N) during one year from November 2007 to December 2008 and studied for total organic carbon (TOC) as well as chromophoric dissolved organic matter (CDOM) optical properties (absorbance and fluorescence). The annual mean value of surface CDOM absorption coefficient ...

  9. Plant diversity and biomass of Marudu bay mangroves in Malaysia

    International Nuclear Information System (INIS)

    Hanum, F.; Kudus, K.A.; Saari, N.S

    2012-01-01

    The mangroves of Marudu Bay in the state of Sabah is situated at the tip of Borneo Island, and at the southern limit of the Coral Triangle whose waters hold the highest diversity of corals, fish, molluscks, crustaceans and marine plant species in the world. The ecosystem shows a deterioration due to unsustainable fishing, pollution and encroachment, and these are impacting the Marudu Bay coastal communities economically. Fishing is the major economic activity here. Realising the importance of conserving the mangroves to uplift the socio-economic livelihood of the coastal community, a resource inventory of the mangroves and its productivity study were carried out. A total of 16 plant species in 12 genera and 9 families were identified. It was also found that 0.7 ha is capable of capturing all the species in the mangrove forest. The mangrove forests of Marudu Bay are dominated by Rhizopora apiculata and R. mucronata. The highest Importance Value index (IVI) was given by Rhizophora mucronata. Total Above Ground Biomass (TAGB) for 1-ha of mangrove forest in Marudu Bay was estimated to be 98.4 t/ha. It was found in other parallel studies that the mangroves of Marudu Bay are productive ecosystems that provide valuable habitats, nurseries and spawning grounds for various commercially important species of fish and invertebrates such as shrimp besides many species of wildlife. The mangroves at Marudu Bay are not only aesthetically attractive but provide opportunities for ecotourism activities that can be undertaken by the local community inhabiting the area to uplift their meagre income, These activities include mangrove cruising, recreational fishing, educational tourism and mangrove honey production, amongst others. This way, the degradation of the mangrove in Marudu Bay can be halted and reversed. (author)

  10. Synoptic volumetric variations and flushing of the Tampa Bay estuary

    Science.gov (United States)

    Wilson, M.; Meyers, S. D.; Luther, M. E.

    2014-03-01

    Two types of analyses are used to investigate the synoptic wind-driven flushing of Tampa Bay in response to the El Niño-Southern Oscillation (ENSO) cycle from 1950 to 2007. Hourly sea level elevations from the St. Petersburg tide gauge, and wind speed and direction from three different sites around Tampa Bay are used for the study. The zonal (u) and meridional (v) wind components are rotated clockwise by 40° to obtain axial and co-axial components according to the layout of the bay. First, we use the subtidal observed water level as a proxy for mean tidal height to estimate the rate of volumetric bay outflow. Second, we use wavelet analysis to bandpass sea level and wind data in the time-frequency domain to isolate the synoptic sea level and surface wind variance. For both analyses the long-term monthly climatology is removed and we focus on the volumetric and wavelet variance anomalies. The overall correlation between the Oceanic Niño Index and volumetric analysis is small due to the seasonal dependence of the ENSO response. The mean monthly climatology between the synoptic wavelet variance of elevation and axial winds are in close agreement. During the winter, El Niño (La Niña) increases (decreases) the synoptic variability, but decreases (increases) it during the summer. The difference in winter El Niño/La Niña wavelet variances is about 20 % of the climatological value, meaning that ENSO can swing the synoptic flushing of the bay by 0.22 bay volumes per month. These changes in circulation associated with synoptic variability have the potential to impact mixing and transport within the bay.

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

    Science.gov (United States)

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

    2013-01-01

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

  12. Terrestrially derived dissolved organic matter in the chesapeake bay and the middle atlantic bight

    Science.gov (United States)

    Mitra, Siddhartha; Bianchi, Thomas S.; Guo, Laodong; Santschi, Peter H.

    2000-10-01

    Concentrations of lignin-phenols were analyzed in high molecular weight dissolved organic matter (0.2 μm > HMW DOM > 1 kDa) isolated from surface waters of the Chesapeake Bay (C. Bay), and surface and bottom waters of the Middle Atlantic Bight (MAB). The abundance of lignin-phenols in HMW DOM was higher in the C. Bay (0.128 ± 0.06 μg L -1) compared to MAB surface waters (0.016 ± 0.004 μg L -1) and MAB bottom waters (0.005 ± 0.003 μg L -1). On an organic carbon-normalized basis, lignin-phenol abundances in the HMW DOM (i.e., Λ 6), were significantly higher ( p vanillin (Ad/Al) V in HMW DOM, indicative of lignin decay, ranged from 0.611 to 1.37 in C. Bay, 0.534 to 2.62 in MAB surface waters, and 0.435 to 1.96 in MAB bottom water. Ratios of S/V and (Ad/Al) V showed no significant differences between each environment, providing no evidence of any compositionally distinct input of terrestrial organic matter into each environment. When considering depth profiles of suspended particulate matter in the MAB, with C:N ratios, and bulk radiocarbon ages and stable carbon isotopic values in HMW DOM isolated from these areas, two scenarios present themselves regarding the sources and transport of terrestrially derived HMW DOM in the MAB. Scenario #1 assumes that a low amount of refractory terrestrial organic matter and old DOC are uniformly distributed in the oceans, both in surface and bottom waters, and that primary production in surface waters increases DOC with low lignin and younger DOC which degrades easily. In this case, many of the trends in age and biomarker composition likely reflect general patterns of Atlantic Ocean surface and bottom water circulation in the area of the MAB. Scenario 2 assumes terrestrial organic matter in bottom waters of the MAB may have originated from weathered shelf and slope sediments in nearshore areas via a combination of mechanisms (e.g., diffusion, recent resuspension events, and/or desorption of DOM from riverine POM buried deep

  13. Monitoring the Northern San Francisco Bay Water Quality with Landsat-8. Nicholas B. Tufillaroa , and Curtiss O. Davisa. aOregon State University, Corvallis, OR, 97331, USA, nbt@coas.oregonstate.edu

    Science.gov (United States)

    Davis, C. O.; Tufillaro, N.

    2016-02-01

    Landsat-8's high spatial resolution ( 30 nm nominal), improved signal-to-noise (12bit digitizer) and expanded band set open up new applications for coastal and in-land waters. We use a recent ocean color processor for Landsat-8 created by Vanhellemont and Ruddick (RSE, 2015)to examine changes in the Northern San Francisco Bay, in particular looking for possiblechanges due to the on-going California drought. For instance, a temporary drought barrier to prevent salt water intrusion was placed during May of 2015 at West False River in the Sacramento-San Joaquin Delta. Using the new Landsat-8 ocean color products, we illustrate how to monitor changes in macro algae and plants (Sago pondweed (native), Curly pondweed (non-native)) in regions directly effected,such as the Franks Track region. Product maps using panchromatic enhancement ( 15 m resolution) andscene based atmospheric correction allow a detailed synoptic look every 16 days during theSpring, Summer, and Fall of 2015. This work is part of a larger NASA funded project aimed atimproving the modeling and predictive capabilities of the biogeochemical state for the San Francisco Bay(Davis, PI: Impacts of Population Growth on the San Francisco Bay and Delta Ecosystem, 2014-2017).

  14. Flooding Simulation of Extreme Event on Barnegat Bay by High-Resolution Two Dimensional Hydrodynamic Model

    Science.gov (United States)

    Wang, Y.; Ramaswamy, V.; Saleh, F.

    2017-12-01

    Barnegat Bay located on the east coast of New Jersey, United States and is separated from the Atlantic Ocean by the narrow Barnegat Peninsula which acts as a barrier island. The bay is fed by several rivers which empty through small estuaries along the inner shore. In terms of vulnerability from flooding, the Barnegat Peninsula is under the influence of both coastal storm surge and riverine flooding. Barnegat Bay was hit by Hurricane Sandy causing flood damages with extensive cross-island flow at many streets perpendicular to the shoreline. The objective of this work is to identify and quantify the sources of flooding using a two dimensional inland hydrodynamic model. The hydrodynamic model was forced by three observed coastal boundary conditions, and one hydrologic boundary condition from United States Geological Survey (USGS). The model reliability was evaluated with both FEMA spatial flooding extend and USGS High water marks. Simulated flooding extent showed good agreement with the reanalysis spatial inundation extents. Results offered important perspectives on the flow of the water into the bay, the velocity and the depth of the inundated areas. Using such information can enable emergency managers and decision makers identify evacuation and deploy flood defenses.

  15. Hydrological mixing and geochemical processes characterization in an estuarine/mangrove system using environmental tracers in Babitonga Bay (Santa Catarina, Brazil)

    Science.gov (United States)

    Barros Grace, Virgínia; Mas-Pla, Josep; Oliveira Novais, Therezinha; Sacchi, Elisa; Zuppi, Gian Maria

    2008-03-01

    The hydrologic complex of Babitonga Bay (Brazil) forms a vast environmental complex where agriculture, shellfish farming, and industries coexist with a unique natural area of Atlantic rain forest and mangrove systems. The origin of different continental hydrological components, the environmental transition between saline and freshwaters, and the influence of the seasonality on Babitonga Bay waters are evaluated using isotopes and chemistry. End-member mixing analysis is used to explore hydrological processes in the bay. We show that a mixing of waters from different origins takes place in the bay modifying its chemical characteristics. Furthermore, biogeochemical processes related to well-developed mangrove systems are responsible for an efficient bromide uptake, which limit its use as a tracer as commonly used in non-biologically active environments. Seasonal behaviours are also distinguished from our datasets. The rainy season (April) provides a homogenization of the hydrological processes that is not seen after the dry season (October), when larger spatial differences appear and when the effects of biological processes on the bay hydrochemistry are more dynamic, or can be better recognized. Moreover, Cl/Br and stable isotopes of water molecule allow a neat definition of the hydrological and biogeochemical processes that control chemical composition in coastal and transition areas.

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

    Science.gov (United States)

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

    2015-10-28

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

  17. A light-water detritiation project at Chalk River Laboratories

    International Nuclear Information System (INIS)

    Boniface, H.A.; Castillo, I.; Everatt, A.E.; Ryland, D.K.

    2010-01-01

    The NRU reactor rod bays is a large, open pool of water that receives hundreds of fuel rods annually, each carrying a small amount of residual tritiated heavy water. The tritium concentration of the rod bays water has risen over the years, to a level that is of concern to the operations staff and to the environment. The proposed long-term solution is to reduce the rod bays tritium concentration by direct detritiation of the water. The Combined Electrolytic-Catalytic Exchange (CECE) process is well suited to the light-water detritiation problem. With a tritium-protium separation factor greater than five, a CECE detritiation process can easily achieve the eight orders of magnitude separation required to split a tritiated light-water feed into an essentially tritium-free effluent stream and a tritiated heavy water product suitable for recycling through a heavy water upgrader. This paper describes a CECE light-water detritiation process specifically designed to reduce the tritium concentration in the NRU rod bays to an acceptable level. The conceptual design of a 600 Mg/a detritiation process has been developed and is now at the stage of project review and the beginning of detailed design. (author)

  18. Is metal pollution a threat to the continued survival of the starfish in False Bay, South Africa?

    Directory of Open Access Journals (Sweden)

    Adriaan J. Reinecke

    2013-02-01

    Full Text Available Urbanisation and industrial development in the catchment area of False Bay in South Africa are increasing and concern was raised about the effect of environmental pollutants on intertidal fauna such as starfish. The aim of the present study was to obtain initial descriptive baseline data over several seasons during 2000–2001 of metal concentrations in water, sediment and body samples of the chosen cushion starfish Parvulastra exigua (Lamarck, 1816 that occurs widely in the intertidal zone of False Bay. Concentrations of cadmium, copper, lead, nickel and zinc were measured in samples of the cushion starfish, water and sediment at five localities along the coast of False Bay. The samples were chemically analysed for metals by atomic spectrophotometry. The highest individually measured concentrations of cadmium (Cd in starfish and sediment were found in the northern coastal region between Strand and Muizenberg where most industrial activity and human settlement occur. Large variation in concentrations of all metals occurred between localities and seasons. The mean concentrations of Cd and Pb in water and sediment were in a few instances slightly higher than the recommended levels or target values of the South African marine water and sediment quality norms but still lower than those in various developed countries. Indications are that the bay was at the time of this study still less contaminated by metals in comparison with the coastal waters of various other countries. The accumulation of nonessential metals such as cadmium and lead in both sediment and bodies of starfish was nevertheless such that it can be assumed that environmental concentrations in some parts of the bay could over time build up to levels that are detrimental to the species as well as their predators. This study provided evidence that the cushion starfish in False Bay is exposed to several metals of which some are potentially hazardous since they tend to gradually accumulate

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

    Science.gov (United States)

    Holmes, C. W.

    2011-12-01

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

  20. The Lower Chesapeake Bay LTAR: A coastal urban-agricultural region

    Science.gov (United States)

    Mccarty, G.; Alfieri, J. G.; Cavigelli, M.; Cosh, M. H.; Hapeman, C. J.; Kustas, W. P.; Maul, J.; Mirsky, S.; Pooler, M.; Sadeghi, A. M.; Schomberg, H.; Timlin, D. J.; Rice, C. P.

    2015-12-01

    The Chesapeake Bay, located in the mid-Atlantic region of the U.S., is the largest estuary in North America. The watershed area includes six states from New York to Virginia and is nearly 167,000 km2 in size with more than 150 rivers and streams entering the 300-km Bay main stem. Forested and agricultural lands make up 58 and 22 percent of the land use, respectively. Nearly 9 percent is urban and suburban use, and the watershed is home to over 17 million people. However, the population is expected to reach 19 million by 2025, raising the potential for conflict between the agricultural and urban communities over land and water use and in protecting natural resources, especially in the lower portion of the Chesapeake Bay watershed. The Lower Chesapeake Bay study area, part of the USDA-ARS Long-Term Agroecosystem Research (LTAR) network, will provide much-needed data to support decisions at this critical agriculture-urban interface. Current long-term projects seek to assess the economic, production, and environmental performance of conventional and organic cropping systems and to evaluate the resilience of these systems to climate change. Large-scale studies are being conducted to examine the effects of land-use and landscape characteristics on ecosystem services and on energy, water, nutrient, carbon, and pest dynamics within watersheds. New in-situ measurement and remote sensor technologies are being considered with the expectancy that the data streams will be available on-line and for use in modeling. Results and outcomes of these research efforts will greatly benefit the national LTAR network and will be applicable to other US coastal urban-agricultural regions.

  1. 75 FR 53266 - United States Army Restricted Area, Designated Portions of Eagle Bay and Eagle River, Fort...

    Science.gov (United States)

    2010-08-31

    ... Richardson, Alaska as well as an adjacent portion of Eagle Bay in the Knik Arm. More specifically, the... affected waters of Eagle Bay and Eagle River in order to enhance safety and security. This portion of Eagle... B. Olson), 441 G Street, NW., Washington, DC 20314-1000. Hand Delivery/Courier: Due to security...

  2. 77 FR 43822 - Proposed Information Collection Request; Comment Request; Valuing Improved Water Quality in the...

    Science.gov (United States)

    2012-07-26

    ... Request; Comment Request; Valuing Improved Water Quality in the Chesapeake Bay Using Stated Preference... efforts to improve water quality in the Chesapeake Bay. In 2009, Executive Order (E.O.) 13508 re... undertaking a benefits analysis of improvements in Bay water quality under the TMDLs, as well as of ancillary...

  3. Application of a Weighted Regression Model for Reporting Nutrient and Sediment Concentrations, Fluxes, and Trends in Concentration and Flux for the Chesapeake Bay Nontidal Water-Quality Monitoring Network, Results Through Water Year 2012

    Science.gov (United States)

    Chanat, Jeffrey G.; Moyer, Douglas L.; Blomquist, Joel D.; Hyer, Kenneth E.; Langland, Michael J.

    2016-01-13

    In the Chesapeake Bay watershed, estimated fluxes of nutrients and sediment from the bay’s nontidal tributaries into the estuary are the foundation of decision making to meet reductions prescribed by the Chesapeake Bay Total Maximum Daily Load (TMDL) and are often the basis for refining scientific understanding of the watershed-scale processes that influence the delivery of these constituents to the bay. Two regression-based flux and trend estimation models, ESTIMATOR and Weighted Regressions on Time, Discharge, and Season (WRTDS), were compared using data from 80 watersheds in the Chesapeake Bay Nontidal Water-Quality Monitoring Network (CBNTN). The watersheds range in size from 62 to 70,189 square kilometers and record lengths range from 6 to 28 years. ESTIMATOR is a constant-parameter model that estimates trends only in concentration; WRTDS uses variable parameters estimated with weighted regression, and estimates trends in both concentration and flux. WRTDS had greater explanatory power than ESTIMATOR, with the greatest degree of improvement evident for records longer than 25 years (30 stations; improvement in median model R2= 0.06 for total nitrogen, 0.08 for total phosphorus, and 0.05 for sediment) and the least degree of improvement for records of less than 10 years, for which the two models performed nearly equally. Flux bias statistics were comparable or lower (more favorable) for WRTDS for any record length; for 30 stations with records longer than 25 years, the greatest degree of improvement was evident for sediment (decrease of 0.17 in median statistic) and total phosphorus (decrease of 0.05). The overall between-station pattern in concentration trend direction and magnitude for all constituents was roughly similar for both models. A detailed case study revealed that trends in concentration estimated by WRTDS can operationally be viewed as a less-constrained equivalent to trends in concentration estimated by ESTIMATOR. Estimates of annual mean flow

  4. Environmental water quality assessment in Guaratuba bay, state of Paraná, southern Brazil

    Directory of Open Access Journals (Sweden)

    Byanka Damian Mizerkowski

    2012-06-01

    Full Text Available An environmental assessment of the estuarine waters of Guaratuba bay, Paraná State, Brazil, is provided through the analysis of physical-chemical, biological and hydrographic dynamics. Twelve stations with a bi-monthly frequency (from October/2002 until August/2003 were sampled during spring and neap tides for the determination of pH, Secchi depth, CO2 saturation, dissolved oxygen, chlorophyll, suspended particulate matter and dissolved inorganic nutrients (nitrate, nitrite, ammonium, phosphate and silicate. Based on the evaluation of six parameters (chlorophyll, Secchi depth, CO2 saturation, dissolved inorganic nitrogen and phosphorus and dissolved oxygen, Guaratuba Bay shows a low to medium trophic status, i.e. from meso- to oligotrophic, and a predominant heterotrophic metabolism, meaning that respiration overcomes primary production. Horizontal stratification was observed during the rainy season, while during the dry season the system showed more homogeneous conditions. Inorganic and/or organic matter in Guaratuba Bay seem to be controlled mainly by the seasonality of precipitation and/ also by ebb and flood tidal phase variations.A dinâmica das variáveis físico-químicas, biológicas e hidrográficas, em escalas temporal e espacial, sua variabilidade e tendências, permite avaliar a qualidade ambiental de estuários. Esse trabalho descreve as flutuações da qualidade de água da Baía de Guaratuba, sul do Estado do Paraná. Foram amostrados doze pontos em campanhas bimensais (outubro/2002 a agosto/2003, em situação de sizígia e de quadratura, para a análise das variáveis pH, transparência, saturação de CO2, oxigênio dissolvido, clorofila-a, material particulado em suspensão e nutrientes inorgânicos dissolvidos (nitrato, nitrito, amônio, fosfato e silicato. Considerando as seis variáveis descritoras da qualidade de água (clorofila-a, profundidade de Secchi, saturação de CO2, fósforo e nitrogênio inorg

  5. 33 CFR 165.1190 - Security Zone; San Francisco Bay, Oakland Estuary, Alameda, CA.

    Science.gov (United States)

    2010-07-01

    ..., Oakland Estuary, Alameda, CA. 165.1190 Section 165.1190 Navigation and Navigable Waters COAST GUARD... § 165.1190 Security Zone; San Francisco Bay, Oakland Estuary, Alameda, CA. (a) Location. The following area is a security zone: All navigable waters of the Oakland Estuary, California, from the surface to...

  6. 75 FR 27552 - Guidance for Federal Land Management in the Chesapeake Bay Watershed

    Science.gov (United States)

    2010-05-17

    ... will allow the federal government to lead the way in protecting the Bay and its watershed with the most effective tools and practices available to reduce water pollution from a variety of nonpoint sources... describe ``proven cost-effective tools and practices that reduce water pollution'' that are appropriate to...

  7. 33 CFR 165.500 - Safety/Security Zones; Chesapeake Bay, Maryland.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety/Security Zones; Chesapeake... HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS... Safety/Security Zones; Chesapeake Bay, Maryland. (a) Definitions. (1) Certain Dangerous Cargo (CDC) means...

  8. Status of macrobenthic community of Manifa-Tanajib Bay System of Saudi Arabia based on a once-off sampling event

    KAUST Repository

    Joydas, Thadickal Viswanathan

    2011-06-01

    Shallow water bays located in the western Arabian Gulf experience harsh environmental conditions. Some of these bays, including Manifa-Tanajib Bay System (MTBS), were also exposed to the 1991 oil pollution event. This study investigates the status of the macrobenthos in MTBS during 2006. This bay system is characterized by very shallow inner bays with elevated salinity and temperature compared to the rest of the bay area. As a result mainly of the hyper salinity, the inner bay communities are distinct from the outer bay communities. Overall, fairly high species richness with several rare species was observed. High Shannon-Wiener diversity values and ABC plots indicated the healthy status of the polychaete communities, while BOPA index indicated slightly polluted status in 20% of the stations. The oil sensitive amphipods were not completely re-colonized in 20% of the stations, even after 15. years of recovery from the 1991 oil spill. © 2011 Elsevier Ltd.

  9. Combined and synergistic effects of climate change and urbanization on water quality in the Wolf Bay watershed, southern Alabama.

    Science.gov (United States)

    Wang, Ruoyu; Kalin, Latif

    2018-02-01

    This study investigated potential changes in flow, total suspended solid (TSS) and nutrient (nitrogen and phosphorous) loadings under future climate change, land use/cover (LULC) change and combined change scenarios in the Wolf Bay watershed, southern Alabama, USA. Four Global Circulation Models (GCMs) under three Special Report Emission Scenarios (SRES) of greenhouse gas were used to assess the future climate change (2016-2040). Three projected LULC maps (2030) were employed to reflect different extents of urbanization in future. The individual, combined and synergistic impacts of LULC and climate change on water quantity/quality were analyzed by the Soil and Water Assessment Tool (SWAT). Under the "climate change only" scenario, monthly distribution and projected variation of TSS are expected to follow a pattern similar to streamflow. Nutrients are influenced both by flow and management practices. The variation of Total Nitrogen (TN) and Total Phosphorous (TP) generally follow the flow trend as well. No evident difference in the N:P ratio was projected. Under the "LULC change only" scenario, TN was projected to decrease, mainly due to the shrinkage of croplands. TP will increase in fall and winter. The N:P ratio shows a strong decreasing potential. Under the "combined change" scenario, LULC and climate change effect were considered simultaneously. Results indicate that if future loadings are expected to increase/decrease under any individual scenario, then the combined change will intensify that trend. Conversely, if their effects are in opposite directions, an offsetting effect occurs. Science-based management practices are needed to reduce nutrient loadings to the Bay. Copyright © 2017. Published by Elsevier B.V.

  10. The feasibility of agricultural uses of thermal effluent from Glace Bay heavy water plant

    International Nuclear Information System (INIS)

    Iverson, S.L.; Puttagunta, V.R.; Meek, K.D.; Chisholm, K.L.

    1978-04-01

    The costs and practicality of pumping effluent water from the GBHWP outfall channel about 500 m to a distribution point, distributing it to up to 25 acres of greenhouses, transferring the heat to the greenhouse air, returning the water to the effluent channel and providing a back-up heat supply were examined. The system described will not interfere with GBHWP operations and can provide a good environment for plant growth at a very attractive price. If a system was designed to serve a 5-acre greenhouse industry, it would cost $18 280 to heat each acre of greenhouse per year ($1.76/GJ), while a system servicing 25 acres could heat greenhouses for only $11 824 per acre per year ($1.14/GJ). This can be compared with the average of $20 000 per acre for fuel alone, paid by Nova Scotia growers in 1975, or the $25 000 per acre per year ($2.40/GJ) calculated in this study as the cost for Bunker C fuel alone at July 1977 prices. The low heating costs possible using waste heat should allow a viable greenhouse industry to be established at Glace Bay, Nova Scotia, and it is recommended that a demonstration greenhouse be constructed to verify the results of this study and demonstrate the technology to potential growers

  11. Water temperature data collected from water temperature logger at 5 locations in Narraganset Bay by Roger Williams University is support of the grant entitled "Could Diseases of Blue Mussels affect commercial culture in the Northeast?" from 2015-05-21 to 2015-12-09 (NCEI Accession 0162404)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains water temperature measurements. Data were collected at 5 Narraganset Bay locations: Arnold Point, Roger Williams University Dock, Dyer Island,...

  12. Evidence for the existence of Persian Gulf water and Red Sea water in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Jain, V.; Shankar, D.; Vinayachandran, P.N.; Kankonkar, A.; Chatterjee, A.; Amol, P.; Almeida, A.M.; Michael, G.S.; Mukherjee, A.; Chatterjee, M.; Fernandes, R.; Luis, R.; Kamble, A.; Hegde, A.; Chatterjee, S.; Das, U.; Neema, C.P.

    data from recent cruises to show that PGW and RSW also exist in the bay. The presence of RSW is marked by a deviation of the salinity vertical profile from a fitted curve at depths ranging from 500 to 1000 m; this deviation, though small (of the order...

  13. Detection of Bay of Bengal eddies from TOPEX and insitu observations

    Digital Repository Service at National Institute of Oceanography (India)

    Ali, M.M.; Sharma, R.; Gopalakrishna, V.V.

    Oceanic eddies are characterised by gradients in the sea surface height (SSH) and temperature both at the surface and the subsurface. However, since the Bay of Bengal waters are more stratified, the gradients in SST may not develop though...

  14. Organic carbon balance and net ecosystem metabolism in Chesapeake Bay

    Science.gov (United States)

    Kemp, W.M.; Smith, E.M.; Marvin-DiPasquale, M.; Boynton, W.R.

    1997-01-01

    The major fluxes of organic carbon associated with physical transport and biological metabolism were compiled, analyzed and compared for the mainstem portion of Chesapeake Bay (USA). In addition, 5 independent methods were used to calculate the annual mean net ecosystem metabolism (NEM = production - respiration) for the integrated Bay. These methods, which employed biogeochemical models, nutrient mass-balances anti summation of individual organic carbon fluxes, yielded remarkably similar estimates, with a mean NEM of +50 g C m-2 yr-1 (?? SE = 751, which is approximately 8% of the estimated annual average gross primary production. These calculations suggest a strong cross-sectional pattern in NEM throughout the Bay, wherein net heterotrophic metabolism prevails in the pelagic zones of the main channel, while net autotrophy occurs in the littoral zones which flank the deeper central area. For computational purposes, the estuary was separated into 3 regions along the land-sea gradient: (1) the oligohaline Upper Bay (11% of total area); (2) the mesohaline Mid Bay (36% of area); and (3) the polyhaline Lower Bay (53% of area). A distinct regional trend in NEM was observed along this salinity gradient, with net here(atrophy (NEM = 87 g C m-2 yr-1) in the Upper Bay, balanced metabolism in the Mid Bay and net autotrophy (NEM = +92 g C m-2 yr-1) in the Lower Bay. As a consequence of overall net autotrophy, the ratio of dissolved inorganic nitrogen (DIN) to total organic nitrogen (TON) changed from DIN:TON = 5.1 for riverine inputs to DIN:TON = 0.04 for water exported to the ocean. A striking feature of this organic C mass-balance was the relative dominance of biologically mediated metabolic fluxes compared to physical transport fluxes. The overall ratio of physical TOC inputs (1) to biotic primary production (P) was 0.08 for the whole estuary, but varied dramatically from 2.3 in the Upper Bay to 0.03 in the Mid and Lower Bay regions. Similarly, ecosystem respiration was

  15. Size-dependent photoacclimation of the phytoplankton community in temperate shelf waters (southern Bay of Biscay)

    KAUST Repository

    Á lvarez, E; Moran, Xose Anxelu G.; Ló pez-Urrutia, Á ; Nogueira, E

    2015-01-01

    © Inter-Research 2016. Shelf waters of the Cantabrian Sea (southern Bay of Biscay) are productive ecosystems with a marked seasonality. We present the results from 1 yr of monthly monitoring of the phytoplankton community together with an intensive sampling carried out in 2 contrasting scenarios during the summer and autumn in a mid-shelf area. Stratification was apparent on the shelf in summer, while the water column was comparatively well mixed in autumn. The size structure of the photoautotrophic community, from pico-to micro-phytoplankton, was tightly coupled with the meteo-climatic and hydrographical conditions. Over the short term, variations in the size structure and chlorophyll content of phytoplankton cells were related to changes in the physico-chemical environment, through changes in the availability of nutrients and light. Uncoupling between the dynamics of carbon biomass and chlorophyll resulted in chlorophyll to carbon ratios dependent on body size. The slope of the size dependence of chlorophyll content increased with increasing irradiance, reflecting different photoacclimation plasticity from pico-to micro-phytoplankton. The results have important implications for the productivity and the fate of biogenic carbon in this region, since the size dependence of photosynthetic rates is directly related to the size scaling of chlorophyll content.

  16. Size-dependent photoacclimation of the phytoplankton community in temperate shelf waters (southern Bay of Biscay)

    KAUST Repository

    Álvarez, E

    2015-12-09

    © Inter-Research 2016. Shelf waters of the Cantabrian Sea (southern Bay of Biscay) are productive ecosystems with a marked seasonality. We present the results from 1 yr of monthly monitoring of the phytoplankton community together with an intensive sampling carried out in 2 contrasting scenarios during the summer and autumn in a mid-shelf area. Stratification was apparent on the shelf in summer, while the water column was comparatively well mixed in autumn. The size structure of the photoautotrophic community, from pico-to micro-phytoplankton, was tightly coupled with the meteo-climatic and hydrographical conditions. Over the short term, variations in the size structure and chlorophyll content of phytoplankton cells were related to changes in the physico-chemical environment, through changes in the availability of nutrients and light. Uncoupling between the dynamics of carbon biomass and chlorophyll resulted in chlorophyll to carbon ratios dependent on body size. The slope of the size dependence of chlorophyll content increased with increasing irradiance, reflecting different photoacclimation plasticity from pico-to micro-phytoplankton. The results have important implications for the productivity and the fate of biogenic carbon in this region, since the size dependence of photosynthetic rates is directly related to the size scaling of chlorophyll content.

  17. Coral bleaching on high-latitude marginal reefs at Sodwana Bay, South Africa

    International Nuclear Information System (INIS)

    Celliers, Louis; Schleyer, Michael H.

    2002-01-01

    Coral bleaching, involving the expulsion of symbiotic zooxanthellae from the host cells, poses a major threat to coral reefs throughout their distributional range. The role of temperature in coral bleaching has been extensively investigated and is widely accepted. A bleaching event was observed on the marginal high-latitude reefs of South Africa located at Sodwana Bay during the summer months of 2000. This was associated with increased sea temperatures with high seasonal peaks in summer and increased radiation in exceptionally clear water. The bleaching was limited to Two-mile Reef and Nine-mile Reef at Sodwana Bay and affected -1 from May 1994 to April 2000. High maximum temperatures were measured (>29 deg. C). The lowest mean monthly and the mean maximum monthly temperatures at which coral bleaching occurred were 27.5 and 28.8 deg. C, respectively, while the duration for which high temperatures occurred in 2000 was 67 days at ≥27.5 deg. C (4 days at ≥28.8 deg. C). Increased water clarity and radiation appeared to be a synergistic cause in the coral bleaching encountered at Sodwana Bay

  18. Daya Bay PWRs will be state-of-the-art

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Preparations for commissioning and startup of the Daya Bay nuclear plant in Guangdong, China, have been underway for some time. The project which incorporates two imported French 900 MWe Pressurized Water Reactors, represents a major technology transfer effort between the Chinese and European contractors, resulting in the highest standards of quality. (author)

  19. Environmental And Area Support Capability Analysis For Seaweed Mariculture Development In Hading Bay Of East Flores Regency

    Directory of Open Access Journals (Sweden)

    Dominikus K. Da Costa

    2015-08-01

    Full Text Available Abstract East Flores regency has adequate marine resources potentials to develop seaweed aquaculture area. Animportant aspect of seaweed aquaculture is the site selection. Site selection is based on the marine area extent and its ecological quality. The objectives of the study were to analyze the water ecology and its support capability and to determine the best site for continuous seaweed mariculture in Hading Bay of East Flores Regency. The study used descriptive method. It was conducted in Hading Bay Lewolema District East Flores Regency in March 2015. Data analysis was done using GIS based on area suitability value and the method applied in the mariculture was long line method. Total Hading Bay water territory was864676 ha. Site Awas135345 ha site B was 474222 ha and site C was 255108 ha. Area with S1 category was 729331 ha extended in Site B and C. Area with S2 category was 135345 ha as extended in Site A. Water territory support capability was 778208 ha. The number of seaweed mariculture units was 194552 units and seaweed territory capacity was 99. Hading Bay waster has the capacity and area support capability for K. alvareziiseaweed mariculture site. Site A was categorized S2 on suitability class and site B and C were categorized S1 on suitability class. The results showed different quality of water territory in those three sites was not significant and still in normal range of K. alvarezii seaweed mariculture development.

  20. Two 24-hour Studies of Water Quality in the Ala Wai Canal during March and July, 1994 for the Mamala Bay Study, Pollutant Source Identification Project MB-3, (NODC Accession 0001188)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset focuses on studies of water quality in the Ala Wai Canal in order to determine its role of point and non point source disharge into Mamala Bay. The...

  1. Cádiz bay walers lurbidily varialions from Landsat TM images analysis

    OpenAIRE

    Gutiérrez Mas, José Manuel; Luna del Barco, A.; Parrado Román, J. M.; Sánchez, E.; Fernández Palacios, A.; Ojeda, J.

    1999-01-01

    Landsat TM images has been analysed to obtain extent and direction data about turbidity flumes in several hydrodinamic sinoptic situations in Cadiz bay waters. Results are beside data from water samples. Five turbidity levels has been differentiated: very high turbidity, high, middle, low and very low, and three geographic sectors: a) Inner zone, closed to coast and with shoal waters of high and very high turbidity. This sector is very affected by littoral processes (tidals, surge and contine...

  2. EFFECTS OF HURRICANE IVAN ON WATER QUALITY IN PENSACOLA BAY, FL USA

    Science.gov (United States)

    Pensacola Bay was in the strong NE quadrant of Hurricane Ivan when it made landfall on September 16, 2004 as a category 3 hurricane on the Saffir-Simpson scale. We present data describing the timeline and maximum height of the storm surge, the extent of flooding of coastal land, ...

  3. Ecological risk assessment of TBT in Ise Bay.

    Science.gov (United States)

    Yamamoto, Joji; Yonezawa, Yoshitaka; Nakata, Kisaburo; Horiguchi, Fumio

    2009-02-01

    An ecological risk assessment of tributyltin (TBT) in Ise Bay was conducted using the margin of exposure (MOE) method. The assessment endpoint was defined to protect the survival, growth and reproduction of marine organisms. Sources of TBT in this study were assumed to be commercial vessels in harbors and navigation routes. Concentrations of TBT in Ise Bay were estimated using a three-dimensional hydrodynamic model, an ecosystem model and a chemical fate model. Estimated MOEs for marine organisms for 1990 and 2008 were approximately 0.1-2.0 and over 100 respectively, indicating a declining temporal trend in the probability of adverse effects. The chemical fate model predicts a much longer persistence of TBT in sediments than in the water column. Therefore, it is necessary to monitor the harmful effects of TBT on benthic organisms.

  4. Gradient Analysis and Classification of Carolina Bay Vegetation: A Framework for Bay Wetlands Conservation and Restoration

    Energy Technology Data Exchange (ETDEWEB)

    Diane De Steven,Ph.D.; Maureen Tone,PhD.

    1997-10-01

    This report address four project objectives: (1) Gradient model of Carolina bay vegetation on the SRS--The authors use ordination analyses to identify environmental and landscape factors that are correlated with vegetation composition. Significant factors can provide a framework for site-based conservation of existing diversity, and they may also be useful site predictors for potential vegetation in bay restorations. (2) Regional analysis of Carolina bay vegetation diversity--They expand the ordination analyses to assess the degree to which SRS bays encompass the range of vegetation diversity found in the regional landscape of South Carolina's western Upper Coastal Plain. Such comparisons can indicate floristic status relative to regional potentials and identify missing species or community elements that might be re-introduced or restored. (3) Classification of vegetation communities in Upper Coastal Plain bays--They use cluster analysis to identify plant community-types at the regional scale, and explore how this classification may be functional with respect to significant environmental and landscape factors. An environmentally-based classification at the whole-bay level can provide a system of templates for managing bays as individual units and for restoring bays to desired plant communities. (4) Qualitative model for bay vegetation dynamics--They analyze present-day vegetation in relation to historic land uses and disturbances. The distinctive history of SRS bays provides the possibility of assessing pathways of post-disturbance succession. They attempt to develop a coarse-scale model of vegetation shifts in response to changing site factors; such qualitative models can provide a basis for suggesting management interventions that may be needed to maintain desired vegetation in protected or restored bays.

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

    NARCIS (Netherlands)

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

    1996-01-01

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

  6. Holocene depositional history of a large glaciated estuary, Penobscot Bay, Maine

    Science.gov (United States)

    Knebel, H.J.

    1986-01-01

    Data from seismic-reflection profiles, sidescan sonar images, and sediment samples reveal the Holocene depositional history of the large (1100 km2) glaciated Penobscot Bay estuary of coastal Maine. Previous work has shown that the late Wisconsinan ice sheet retreated from the three main passages of the bay between 12,700 and 13,500 years ago and was accompanied by a marine transgression during which ice and sea were in contact. Isostatic recovery of the crust caused the bay to emerge during the immediate postglacial period, and relative sea level fell to at least -40 m sometime between 9000 and 11,500 years ago. During lowered sea level, the ancestral Penobscot River flowed across the subaerially exposed head of the bay and debouched into Middle Passage. Organic-matter-rich mud from the river was deposited rapidly in remnant, glacially scoured depressions in the lower reaches of Middle and West Passages behind a shallow (???20 m water depth) bedrock sill across the bay mouth. East Passage was isolated from the rest of the bay system and received only small amounts of locally derived fine-grained sediments. During the Holocene transgression that accompanied the eustatic rise of sea level, the locus of sedimentation shifted to the head of the bay. Here, heterogeneous fluvial deposits filled the ancestral valley of the Penobscot River as base level rose, and the migrating surf zone created a gently dipping erosional unconformity, marked by a thin (energy conditions and the waning influence of the Penobscot River at the head of the bay. In contrast, relatively thick (up to 25 m) silty clays accumulated within a subbottom trough in the western half of the bay head. This deposit apparently developed late in the transgression after sea level had reached -20 m and after the westward transport of fine-grained sediments from the Penobscot River had been established. During and since the late Holocene transgression of sea level, waves and currents have eroded, reworked, and

  7. Studies on seasonal pollution of heavy metals in water, sediment, fish and oyster from the Meiliang Bay of Taihu Lake in China.

    Science.gov (United States)

    Rajeshkumar, Sivakumar; Liu, Yang; Zhang, Xiangyang; Ravikumar, Boopalan; Bai, Ge; Li, Xiaoyu

    2018-01-01

    The present study, seasonal pollution of heavy metals (Pb, Cd, Cr and Cu) in water, sediment, tissues of fish Carassius carassius and oyster Crassostrea gigas were determined at seven sampling sites from Meiliang Bay, Taihu Lake during one year calendar, 2016. The total heavy metal concentrations in water samples were higher in winter and summer than in spring and autumn season, whereas in sediment they were higher in winter and summer seasons, respectively. The trend of metal mean contents found in the fish and oyster were in decreasing order of Pb > Cu > Cr > Cd and Pb > Cu > Cr > Cd, respectively. The tissues of fish and oyster captured during winter and summer accumulated a higher significant different amount of metals relative to other season, which was attributed to a higher influx of agricultural waste, sewage and sludge by heavy rainfall and floods. In addition, the pollution load index (PLI) values were above one (>1), indicating an advanced decline of the sediment quality, and contamination factor (CF) confirmed that the sediment samples were moderate to high contamination by Pb and Cr. Thus, comparative studies with seasonal pollution of heavy metals in Meiliang Bay of Lake Taihu regions indicate considerable heavy metal enrichment in water, sediments as well as in various organs of fish and oyster. Finally, our results indicated that the metal concentration values increased statistically significant different related to season (p heavy metal stress biomarkers in fish along with seasonal variations may serve as a convenient approach during pollution bio-monitoring programme. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. 77 FR 14471 - Safety Zone; Festival of States 2012 Night Parade Fireworks Display, Tampa Bay, St. Petersburg, FL

    Science.gov (United States)

    2012-03-12

    ... Zone; Festival of States 2012 Night Parade Fireworks Display, Tampa Bay, St. Petersburg, FL AGENCY... safety zone on the waters of Tampa Bay in St. Petersburg, Florida during Festival of States 2012 Night... Thursday, March 22, 2012, the Festival of States 2012 Night Parade Fireworks Display is scheduled to take...

  9. Horizontal and vertical dynamics of zooplankton and larval fish communities during mid-summer in Disko Bay, West Greenland

    DEFF Research Database (Denmark)

    Munk, Peter; Nielsen, Torkel Gissel; Hansen, Benni Winding

    2015-01-01

    Disko Bay is a highly productive inlet at the border between high- and low-arctic sectors of west Greenland. The physical/chemical conditions in the bay have changed during recent decades, specifically during an inflow event in 1996–1997 that led to increased deep-water temperatures. To further u...

  10. The radon monitoring system in Daya Bay Reactor Neutrino Experiment

    International Nuclear Information System (INIS)

    Chu, M.C.; Kwan, K.K.; Kwok, M.W.; Kwok, T.; Leung, J.K.C.; Leung, K.Y.; Lin, Y.C.; Luk, K.B.; Pun, C.S.J.

    2016-01-01

    We developed a highly sensitive, reliable and portable automatic system (H 3 ) to monitor the radon concentration of the underground experimental halls of the Daya Bay Reactor Neutrino Experiment. H 3 is able to measure radon concentration with a statistical error less than 10% in a 1-h measurement of dehumidified air (R.H. 5% at 25 °C) with radon concentration as low as 50 Bq/m 3 . This is achieved by using a large radon progeny collection chamber, semiconductor α-particle detector with high energy resolution, improved electronics and software. The integrated radon monitoring system is highly customizable to operate in different run modes at scheduled times and can be controlled remotely to sample radon in ambient air or in water from the water pools where the antineutrino detectors are being housed. The radon monitoring system has been running in the three experimental halls of the Daya Bay Reactor Neutrino Experiment since November 2013.

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

    Science.gov (United States)

    Schoellhamer, David H.; ,

    1990-01-01

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

  12. Impact of Bay-Breeze Circulations on Surface Air Quality and Boundary Layer Export

    Science.gov (United States)

    Loughner, Christopher P.; Tzortziou, Maria; Follette-Cook, Melanie; Pickering, Kenneth E.; Goldberg, Daniel; Satam, Chinmay; Weinheimer, Andrew; Crawford, James H.; Knapp, David J.; Montzka, Denise D.; hide

    2014-01-01

    Meteorological and air-quality model simulations are analyzed alongside observations to investigate the role of the Chesapeake Bay breeze on surface air quality, pollutant transport, and boundary layer venting. A case study was conducted to understand why a particular day was the only one during an 11-day ship-based field campaign on which surface ozone was not elevated in concentration over the Chesapeake Bay relative to the closest upwind site and why high ozone concentrations were observed aloft by in situ aircraft observations. Results show that southerly winds during the overnight and early-morning hours prevented the advection of air pollutants from the Washington, D.C., and Baltimore, Maryland, metropolitan areas over the surface waters of the bay. A strong and prolonged bay breeze developed during the late morning and early afternoon along the western coastline of the bay. The strength and duration of the bay breeze allowed pollutants to converge, resulting in high concentrations locally near the bay-breeze front within the Baltimore metropolitan area, where they were then lofted to the top of the planetary boundary layer (PBL). Near the top of the PBL, these pollutants were horizontally advected to a region with lower PBL heights, resulting in pollution transport out of the boundary layer and into the free troposphere. This elevated layer of air pollution aloft was transported downwind into New England by early the following morning where it likely mixed down to the surface, affecting air quality as the boundary layer grew.

  13. Large-Scale Submerged Aquatic Vegetation Restoration in Chesapeake Bay: Status Report, 2003-2006

    National Research Council Canada - National Science Library

    Shafer, Deborah J; Bergstrom, Peter

    2008-01-01

    ...) in the Chesapeake Bay region. The effort employed an agricultural approach to restore under-water grasses by using seeds to produce new plants and mechanical equipment to plant seeds and harvest...

  14. Ground-Water Quality Data in the Monterey Bay and Salinas Valley Basins, California, 2005 - Results from the California GAMA Program

    Science.gov (United States)

    Kulongoski, Justin T.; Belitz, Kenneth

    2007-01-01

    Ground-water quality in the approximately 1,000-square-mile Monterey Bay and Salinas Valley study unit was investigated from July through October 2005 as part of the California Ground-Water Ambient Monitoring and Assessment (GAMA) program. The study was designed to provide a spatially unbiased assessment of raw ground-water quality, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 94 public-supply wells and 3 monitoring wells in Monterey, Santa Cruz, and San Luis Obispo Counties. Ninety-one of the public-supply wells sampled were selected to provide a spatially distributed, randomized monitoring network for statistical representation of the study area. Six wells were sampled to evaluate changes in water chemistry: three wells along a ground-water flow path were sampled to evaluate lateral changes, and three wells at discrete depths from land surface were sampled to evaluate changes in water chemistry with depth from land surface. The ground-water samples were analyzed for volatile organic compounds (VOCs), pesticides, pesticide degradates, nutrients, major and minor ions, trace elements, radioactivity, microbial indicators, and dissolved noble gases (the last in collaboration with Lawrence Livermore National Laboratory). Naturally occurring isotopes (tritium, carbon-14, helium-4, and the isotopic composition of oxygen and hydrogen) also were measured to help identify the source and age of the sampled ground water. In total, 270 constituents and water-quality indicators were investigated for this study. This study did not attempt to evaluate the quality of water delivered to consumers; after withdrawal from the ground, water typically is treated, disinfected, and (or) blended with other waters to maintain water quality. In addition, regulatory thresholds apply to treated water that is served to the consumer, not to raw ground water. In this study, only six constituents, alpha radioactivity, N

  15. Seasonal estimates of DOC standing stocks in Apalachicola Bay estuary: Towards a better understanding using field, ocean color and model data

    Science.gov (United States)

    D'Sa, E. J.; Joshi, I.; Osburn, C. L.; Bianchi, T. S.; Ko, D. S.; Oviedo-Vargas, D.; Arellano, A.; Ward, N.

    2016-12-01

    Apalachicola Bay, a semi-enclosed estuary located in Florida's panhandle, is well known for its water quality and oyster yields. We present the use of combined field and ocean color satellite observations and the outputs of a high-resolution hydrodynamic model to study the influence of physical processes on the distribution and the transport of terrestrially derived CDOM and DOC to shelf waters during the spring and fall of 2015. Determination of DOC stocks were based on the development of a CDOM algorithm (R2 = 0.87, N = 9) for the VIIRS ocean color sensor, and the assessment of CDOM - DOC relationships (R2 = 0.88, N = 13 in March; R2 = 0.83, N = 24 in November) for the Apalachicola Bay. Satellite-derived CDOM and DOC maps together with model-based salinity distributions revealed their spatial extent, sources and transport to the shelf water. Furthermore, strong seasonal influence on DOM distribution in the bay was associated with inputs from Apalachicola and Carrabelle Rivers and the surrounding marshes. Estimates of DOC standing stocks in the bay obtained using ocean color data and high-resolution bathymetry showed relatively higher stocks in November ( 3.71 × 106 kg C, 560 km2) than in March ( 4.07 × 106 kg C, 560 km2) despite lower river discharge in dry season. Results of DOC flux estimates from the bay to coastal waters will also be presented.

  16. 46 CFR 7.20 - Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and...

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...

  17. Hydrodynamic Aspects at Vitória Bay Mouth, ES

    Directory of Open Access Journals (Sweden)

    FLÁVIA A.A. GARONCE

    2014-06-01

    Full Text Available Understading the hydrodynamic behavior and suspended particulated matter (SPM transport are of great importance in port regions such as Vitória Harbor, which is located at Vitória Bay, Vitória – ES, Brazil. Vitória Bay is an estuary that has not been systematically assessed through a temporal analysis in order to identify its hydrodynamics characteristics and SPM exchange. This study aims to investigate salt and suspended particulate matter flux at the estuarine mouth of Vitória Bay by understanding the temporal variation of salinity, temperature and tidal currents within the water column and at the channel crosssection. Results showed that the estuarine mouth tended to present partial stratification periods during neap tides and little stratification in spring tides. The circulation pattern was mainly influenced by the tide, with little influence from river discharge. With regard to the SPM, the mouth of the estuary tended to show low concentrations, with the highest values occurring during the dry season. A close relationship between momentary discharge, SPM and salt fluxes was observed. Despite all the data was collected at the mouth of the estuary, the system showed an importation trend of salt in all cycles and SPM importation for three of the four studied tidal cycles. Thus, Vitoria Bay is not exporting SPM to the adjacent inner shelf.

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

    Science.gov (United States)

    Radtke, D.B.

    1985-01-01

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

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

    Science.gov (United States)

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

    1983-01-01

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

  20. Long-term oceanographic observations in Massachusetts Bay, 1989-2006

    Science.gov (United States)

    Butman, Bradford; Alexander, P. Soupy; Bothner, Michael H.; Borden, Jonathan; Casso, Michael A.; Gutierrez, Benjamin T.; Hastings, Mary E.; Lightsom, Frances L.; Martini, Marinna A.; Montgomery, Ellyn T.; Rendigs, Richard R.; Strahle, William S.

    2009-01-01

    This data report presents long-term oceanographic observations made in western Massachusetts Bay at long-term site A (LT-A) (42 deg 22.6' N., 70 deg 47.0' W.; nominal water depth 32 meters) from December 1989 through February 2006 and long-term site B (LT-B) (42 deg 9.8' N., 70 deg 38.4' W.; nominal water depth 22 meters) from October 1997 through February 2004 (fig. 1). The observations were collected as part of a U.S. Geological Survey (USGS) study designed to understand the transport and long-term fate of sediments and associated contaminants in Massachusetts Bay. The observations include time-series measurements of current, temperature, salinity, light transmission, pressure, oxygen, fluorescence, and sediment-trapping rate. About 160 separate mooring or tripod deployments were made on about 90 research cruises to collect these long-term observations. This report presents a description of the 16-year field program and the instrumentation used to make the measurements, an overview of the data set, more than 2,500 pages of statistics and plots that summarize the data, and the digital data in Network Common Data Form (NetCDF) format. This research was conducted by the USGS in cooperation with the Massachusetts Water Resources Authority and the U.S. Coast Guard.

  1. The regulation of bacterial production in the Chesapeake Bay

    International Nuclear Information System (INIS)

    Chin-Leo, G.

    1988-01-01

    In this study, the possibility that periods when the rates of macromolecule syntheses become uncoupled occur in natural assemblages of bacteria was examined by comparing rates of bacterial DNA and protein synthesis. A dual-label method which measures incorporation rates of [ 3 H]thymidine (TdR) into macromolecules (DNA) and of [ 14 C]leucine (Leu) into protein was developed to facilitate simultaneous estimation of these cellular activities in a single incubation. Under controlled conditions, changes in rates of Leu incorporation preceded fluctuations in TdR incorporation and the Leu:TdR ratio varied prior to shifts in growth rate indicating the uncoupling of protein and DNA synthesis which occurs during unbalanced growth. The delay between this uncoupling and a change in growth rate was always shorter than the generation time. In Chesapeake Bay, during October 1986, the Leu:TdR ratio was quite constant over a diel cycle and with depth, but during July 1987, the magnitude of this ratio and its variation through time increased with depth. Growth conditions for heterotrophic bacteria in Chesapeake Bay during summer in surface waters and throughout the water column in fall may be relatively constant leading to balanced growth. In contrast, fluctuating growth conditions in subsurface waters during summer may lead to unbalanced growth

  2. [Mercury concentration of fish in Tokyo Bay and the surrounding sea area].

    Science.gov (United States)

    Zhang, R; Kashima, Y; Matsui, M; Okabe, T; Doi, R

    2001-07-01

    Total mercury in the muscles of three fish species was analyzed in fish caught in Tokyo Bay and the surrounding sea areas, Sagami Bay and Choshi. Tokyo Bay is a semi-closed sea area surrounded by Tokyo, Kanagawa and Chiba prefectures. Sagami Bay and Choshi are open to the Pacific Ocean. A total of 412 fish consisting of northern whiting (Sillago japonica), flatfish (Limanda yokohamae) and sardine (Sardinops melanosticta) were caught in these areas over a 6 months period from November 1998 to April 1999. Total mercury concentration ranged from 0.008-0.092 microgram/g (wet wt.) in northern whiting, 0.006-0.065 microgram/g in flatfish and 0.001-0.045 microgram/g in sardine. All concentrations were below the restriction limit of fish mercury in Japan, 0.4 microgram/g of total mercury concentration. A significant correlation was found between mercury concentrations and body length or body weight in northern whiting and flatfish, irrespective of the sea area. A correlation was also found between mercury concentration in fish and their feeding habits: among the 3 species caught in the same area, crustacean feeding northern whiting had the highest, polychaete feeding flatfish moderate, and plankton feeding sardine had the lowest mercury concentration. In a comparison of mercury concentration in the same species caught in different sea areas, a higher concentration was noted in fish caught in the semi-closed sea area of Tokyo Bay, than in fish caught in the open sea areas of Sagami Bay and Choshi. This difference was most marked in fish caught at the bottom of Tokyo Bay and we considered that the mercury concentration of seawater and sediment in these areas was the cause of mercury accumulation in fish. These findings suggest that improved water quality control and environmental monitoring is necessary in semi-closed sea areas such as Tokyo Bay.

  3. The movement and implications of the Ganges-Bramhaputra runoff on entering the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.

    The Ganges-Brahmaputra rivers discharge annually approximately 10 sup(2) m sup(3) of freshwater into the Bay of Bengal at its northern end. We propose that the spread of this water, accompaniEd. by mixing with the ambient waters, occurs in three...

  4. Effect of the Discharge Water which Mixed Sewage Disposal Water with Seawater Desalting Treated Sewage for Bottom Sediment and Hypoxic Water Mass

    Science.gov (United States)

    Watanabe, Ryoichi; Yamasaki, Koreyoshi; Minagawa, Tomoko; Iyooka, Hiroki; Kitano, Yoshinori

    For every time in summer season, hypoxic water mass has formed at the inner part of Hakata Bay. Field observation study has carried out at the inner part of Hakata Bay since 2004 with the particular aim of tracking the movement of hypoxic water mass. Hypoxic water masses form the end of June to September on this area because the consumption of oxygen in bottom water layers exceeds the re-supply of oxygen from the atmosphere. Under such hypoxic conditions, the seawater desalination plant has begun to use in 2005. After seawater desalination plant operation starting, hypoxic water mass tends to improve. In this research, the authors show the following result. After seawater desalination plant has begun to operate, the hypoxia around the mixed discharge water outlet tends to be improved.

  5. Volcanisme, activité anthropique et circulation des masses océaniques : leur influence respective sur la distribution des populations d'ostracodes dans la baie de Kagoshima (île de Kyushu, Japon)Impact of volcanism, human activities, and water mass circulation on the distribution of ostracod populations in Kagoshima Bay (Kyushu Island, southern Japan)

    Science.gov (United States)

    Bodergat, Anne-Marie; Oki, Kimihiko; Ishizaki, Kunihiro; Rio, Michel

    2002-11-01

    The distribution of ostracod populations in Kagoshima Bay (Japan) is analysed with reference to different environmental parameters. The bay is an area of volcanic activity of Sakurajima volcano under the influence of the Kuroshio Current. Most of the Head environment is occupied by an acidic water mass. Numbers of individual and species decrease from the Mouth of the bay towards the Basin and Head environments. In this latter, acidic water mass has a drastic effect on ostracod populations, whereas volcanic ashes and domestic inputs are not hostile. Ostracod distribution is influenced by the quality and structure of water masses. To cite this article: A.-M. Bodergat et al., C. R. Geoscience 334 (2002) 1053-1059.

  6. Ecology of selected marine communities in Glacier Bay: Zooplankton, forage fish, seabirds and marine mammals

    Science.gov (United States)

    Robards, Martin D.; Drew, Gary S.; Piatt, John F.; Anson, Jennifer Marie; Abookire, Alisa A.; Bodkin, James L.; Hooge, Philip N.; Speckman, Suzann G.

    2003-01-01

    We studied oceanography (including primary production), secondary production, small schooling fish (SSF), and marine bird and mammal predators in Glacier Bay during 1999 and 2000. Results from these field efforts were combined with a review of current literature relating to the Glacier Bay environment. Since the conceptual model developed by Hale and Wright (1979) ‘changes and cycles’ continue to be the underlying theme of the Glacier Bay ecosystem. We found marked seasonality in many of the parameters that we investigated over the two years of research, and here we provide a comprehensive description of the distribution and relative abundance of a wide array of marine biota. Glacier Bay is a tidally mixed estuary that leads into basins, which stratify in summer, with the upper arms behaving as traditional estuaries. The Bay is characterized by renewal and mixing events throughout the year, and markedly higher primary production than in many neighboring southeast Alaska fjords (Hooge and Hooge, 2002). Zooplankton diversity and abundance within the upper 50 meters of the water column in Glacier Bay is similar to communities seen throughout the Gulf of Alaska. Zooplankton in the lower regions of Glacier Bay peak in abundance in late May or early June, as observed at Auke Bay and in the Gulf of Alaska. The key distinction between the lower Bay and other estuaries in the Gulf of Alaska is that a second smaller peak in densities occurs in August. The upper Bay behaved uniformly in temporal trends, peaking in July. Densities had begun to decline in August, but were still more than twice those observed in that region in May. The highest density of zooplankton observed was 17,870 organisms/m3 in Tarr Inlet during July. Trends in zooplankton community abundance and diversity within the lower Bay were distinct from upper-Glacier Bay trends. Whereas the lower Bay is strongly influenced by Gulf of Alaska processes, local processes are the strongest influence in the upper-Bay

  7. Accelerate Water Quality Improvement

    Science.gov (United States)

    EPA is committed to accelerating water quality improvement and minimizing negative impacts to aquatic life from contaminants and other stressors in the Bay Delta Estuary by working with California Water Boards to strengthen water quality improvement plans.

  8. Identification of spatiotemporal nutrient patterns in a coastal bay via an integrated k-means clustering and gravity model.

    Science.gov (United States)

    Chang, Ni-Bin; Wimberly, Brent; Xuan, Zhemin

    2012-03-01

    This study presents an integrated k-means clustering and gravity model (IKCGM) for investigating the spatiotemporal patterns of nutrient and associated dissolved oxygen levels in Tampa Bay, Florida. By using a k-means clustering analysis to first partition the nutrient data into a user-specified number of subsets, it is possible to discover the spatiotemporal patterns of nutrient distribution in the bay and capture the inherent linkages of hydrodynamic and biogeochemical features. Such patterns may then be combined with a gravity model to link the nutrient source contribution from each coastal watershed to the generated clusters in the bay to aid in the source proportion analysis for environmental management. The clustering analysis was carried out based on 1 year (2008) water quality data composed of 55 sample stations throughout Tampa Bay collected by the Environmental Protection Commission of Hillsborough County. In addition, hydrological and river water quality data of the same year were acquired from the United States Geological Survey's National Water Information System to support the gravity modeling analysis. The results show that the k-means model with 8 clusters is the optimal choice, in which cluster 2 at Lower Tampa Bay had the minimum values of total nitrogen (TN) concentrations, chlorophyll a (Chl-a) concentrations, and ocean color values in every season as well as the minimum concentration of total phosphorus (TP) in three consecutive seasons in 2008. The datasets indicate that Lower Tampa Bay is an area with limited nutrient input throughout the year. Cluster 5, located in Middle Tampa Bay, displayed elevated TN concentrations, ocean color values, and Chl-a concentrations, suggesting that high values of colored dissolved organic matter are linked with some nutrient sources. The data presented by the gravity modeling analysis indicate that the Alafia River Basin is the major contributor of nutrients in terms of both TP and TN values in all seasons

  9. eBay.com

    DEFF Research Database (Denmark)

    Engholm, Ida

    2014-01-01

    Celebrated as one of the leading and most valuable brands in the world, eBay has acquired iconic status on par with century-old brands such as Coca-Cola and Disney. The eBay logo is now synonymous with the world’s leading online auction website, and its design is associated with the company...

  10. Continuous resistivity profiling data from Great South Bay, Long Island, New York

    Science.gov (United States)

    Cross, V.A.; Bratton, J.F.; Kroeger, K.D.; Crusius, John; Worley, C.R.

    2013-01-01

    An investigation of submarine aquifers adjacent to the Fire Island National Seashore and Long Island, New York was conducted to assess the importance of submarine groundwater discharge as a potential nonpoint source of nitrogen delivery to Great South Bay. Over 200 kilometers of continuous resistivity profiling data were collected to image the fresh-saline groundwater interface in sediments beneath the bay. In addition, groundwater sampling was performed at sites (1) along the north shore of Great South Bay, particularly in Patchogue Bay, that were representative of the developed Long Island shoreline, and (2) at sites on and adjacent to Fire Island, a 50-kilometer-long barrier island on the south side of Great South Bay. Other field activities included sediment coring, stationary electrical resistivity profiling, and surveys of in situ pore water conductivity. Results of continuous resistivity profiling surveys are described in this report. The onshore and offshore shallow hydrostratigraphy of the Great South Bay shorelines, particularly the presence and nature of submarine confining units, appears to exert primary control on the dimensions and chemistry of the submarine groundwater flow and discharge zones. Sediment coring has shown that the confining units commonly consist of drowned and buried peat layers likely deposited in salt marshes. Low-salinity groundwater extends from 10 to 100 meters offshore along much of the north and south shores of Great South Bay based on continuous resistivity profiling data, especially off the mouths of tidal creeks and beneath shallow flats to the north of Fire Island adjacent to modern salt marshes. Human modifications of much of the shoreline and nearshore areas along the north shore of the bay, including filling of salt marshes, construction of bulkheads and piers, and dredging of navigation channels, has substantially altered the natural hydrogeology of the bay's shorelines by truncating confining units and increasing

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

    OpenAIRE

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

    2010-01-01

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

  12. Sensibility Study of St Andrew Bay Rapid Response System for Naval Applications

    National Research Council Canada - National Science Library

    Pauly, Patrice

    2005-01-01

    .... For the physical part, time constraint may limit to using the barotropic mode. But because rain can be significant in St Andrew Bay system, Florida, fresh water, even when rivers lack, is a prevailing salinity regulator through ground seepage...

  13. Oceanographic studies in Harrison Bay and the Colville River Delta, Alaska, to support the development of oil spill response strategies

    International Nuclear Information System (INIS)

    Owens, E.H.; Taylor, E.; Hale, B.

    2003-01-01

    The risk of an oil spill resulting from the development of the Alpine oil field is considered to be low. The field is located on the North Slope of Alaska adjacent to the Alaskan Beaufort Sea and reaches coastal waters from the distributary channels of the Colville River Delta. The physical environmental (hydrodynamic) conditions that would affect the transport and fate of spilled oil was investigated to further reduce the risk. During the open-water season of 2001 in Harrison Bay, near shore current meters were deployed and data on weather and surface currents was analyzed. Ocean current and wind measurements were examined to evaluate the relationship between meteorology and water levels during the open-water season. The objective was to gain a better understanding of the near shore hydrodynamic processes at play in Harrison Bay, in order to plan the most appropriate spill response strategies. The results obtained indicate that surface currents within the bay adjacent to the Colville Delta are variable. They respond to wind forces as well as other possible mechanisms like estuarine circulation. The surface currents reach maximum speeds of 0.26 metre per second. For the late July-September deployment, the calculated net surface drift was a 0.02 metre per second current to the east southeast. In both Harrison Bay and Colville Delta, prevailing southwest and northeast winds, respectively, induced water level changes of more than 0.5 metre above and below the average. 7 refs., 3 tabs., 7 figs

  14. Hydrogeology and geochemistry of aquifers underlying the San Lorenzo and San Leandro areas of the East Bay Plain, Alameda County, California

    Science.gov (United States)

    Izbicki, John A.; Borchers, James W.; Leighton, David A.; Kulongoski, Justin T.; Fields, Latoya; Galloway, Devin L.; Michel, Robert L.

    2003-01-01

    The East Bay Plain, on the densely populated eastern shore of San Francisco Bay, contains an upper aquifer system to depths of 250 feet below land surface and an underlying lower aquifer system to depths of more than 650 feet. Injection and recovery of imported water has been proposed for deep aquifers at two sites within the lower aquifer system. Successful operation requires that the injected water be isolated from surface sources of poor-quality water during storage and recovery. Hydraulic, geochemical, and isotopic data were used to evaluate the isolation of deeper aquifers. Ground-water responses to tidal changes in the Bay suggest that thick clay layers present within these deposits effectively isolate the deeper aquifers in the northern part of the study area from overlying surficial deposits. These data also suggest that the areal extent of the shallow and deep aquifers beneath the Bay may be limited in the northern part of the study area. Despite its apparent hydraulic isolation, the lower aquifer system may be connected to the overlying upper aquifer system through the corroded and failed casings of abandoned wells. Water-level measurements in observation wells and downward flow measured in selected wells during nonpumped conditions suggest that water may flow through wells from the upper aquifer system into the lower aquifer system during nonpumped conditions. The chemistry of water from wells in the East Bay Plain ranges from fresh to saline; salinity is greater than seawater in shallow estuarine deposits near the Bay. Water from wells completed in the lower aquifer system has higher pH, higher sodium, chloride, and manganese concentrations, and lower calcium concentrations and alkalinity than does water from wells completed in the overlying upper aquifer system. Ground-water recharge temperatures derived from noble-gas data indicate that highly focused recharge processes from infiltration of winter streamflow and more diffuse recharge processes from

  15. Hydrogeologic controls and geochemical indicators of groundwater movement in the Niles Cone and southern East Bay Plain groundwater subbasins, Alameda County, California

    Science.gov (United States)

    Teague, Nicholas F.; Izbicki, John A.; Borchers, Jim; Kulongoski, Justin T.; Jurgens, Bryant C.

    2018-02-01

    Beginning in the 1970s, Alameda County Water District began infiltrating imported water through ponds in repurposed gravel quarries at the Quarry Lakes Regional Park, in the Niles Cone groundwater subbasin, to recharge groundwater and to minimize intrusion of saline, San Francisco Bay water into freshwater aquifers. Hydraulic connection between distinct aquifers underlying Quarry Lakes allows water to recharge the upper aquifer system to depths of 400 feet below land surface, and the Deep aquifer to depths of more than 650 feet. Previous studies of the Niles Cone and southern East Bay Plain groundwater subbasins suggested that these two subbasins may be hydraulically connected. Characterization of storage capacities and hydraulic properties of the complex aquifers and the structural and stratigraphic controls on groundwater movement aids in optimal storage and recovery of recharged water and provides information on the ability of aquifers shared by different water management agencies to fulfill competing storage and extraction demands. The movement of recharge water through the Niles Cone groundwater subbasin from Quarry Lakes and the possible hydraulic connection between the Niles Cone and the southern East Bay Plain groundwater subbasins were investigated using interferometric synthetic aperture radar (InSAR), water-chemistry, and isotopic data, including tritium/helium-3, helium-4, and carbon-14 age-dating techniques.InSAR data collected during refilling of the Quarry Lakes recharge ponds show corresponding ground-surface displacement. Maximum uplift was about 0.8 inches, reasonable for elastic expansion of sedimentary materials experiencing an increase in hydraulic head that resulted from pond refilling. Sodium concentrations increase while calcium and magnesium concentrations in groundwater decrease along groundwater flowpaths from the Niles Cone groundwater subbasin through the Deep aquifer to the northwest toward the southern East Bay Plain groundwater

  16. Classification using Hierarchical Naive Bayes models

    DEFF Research Database (Denmark)

    Langseth, Helge; Dyhre Nielsen, Thomas

    2006-01-01

    Classification problems have a long history in the machine learning literature. One of the simplest, and yet most consistently well-performing set of classifiers is the Naïve Bayes models. However, an inherent problem with these classifiers is the assumption that all attributes used to describe......, termed Hierarchical Naïve Bayes models. Hierarchical Naïve Bayes models extend the modeling flexibility of Naïve Bayes models by introducing latent variables to relax some of the independence statements in these models. We propose a simple algorithm for learning Hierarchical Naïve Bayes models...

  17. Modeling Photosynthetically Active Radiation in Water of Tampa Bay, Florida, with Emphasis on the Geometry of Incident Irradiance

    Science.gov (United States)

    Miller, Ronald L.; McPherson, Benjamin F.

    1995-04-01

    Field studies that compare the spatial and temporal variation in light attenuation often neglect effects of solar elevation angle, yet these effects can be significant. To approximately correct for these angular effects, we developed a model that uses a simplified geometric description of incident direct solar beam and diffuse skylight. The model incorporates effects of solar elevation angle and cloudiness on the amount of in-air photosynthetically active radiation (PAR) that passes through the air-water interface and on K0in waters of relatively low turbidity. The model was calibrated with 3266 5-min averages of scalar PAR measured in air and at two depths in water and permits the value of K0to be adjusted approximately for the effects of time of day, season and cloudiness. The model was then used with 255 days of in-air PAR data (15-min averages) to evaluate irradiance that entered the water and attenuation in the water. On an annual basis, 49% of the incident scalar irradiance, or 380 μmol m -2s -1, was estimated to enter the water of Tampa Bay. The value of K0was estimated to vary as much as 41% on a clear summer day due to changes in solar elevation angle. The model was used to make estimates of the depth to which sea-grasses might receive adequate light for survival for a range of values of K0. This approach should be useful for projecting the effect of changes in water clarity on the depth of sea-grass survival and for comparing values of K0collected at different times of day and in different seasons.

  18. 75 FR 11837 - Chesapeake Bay Watershed Initiative

    Science.gov (United States)

    2010-03-12

    ... DEPARTMENT OF AGRICULTURE Commodity Credit Corporation Chesapeake Bay Watershed Initiative AGENCY...: Notice of availability of program funds for the Chesapeake Bay Watershed Initiative. SUMMARY: The... through the Chesapeake Bay Watershed Initiative for agricultural producers in the Chesapeake Bay watershed...

  19. Coordinating water conservation efforts through tradable credits: A proof of concept for drought response in the San Francisco Bay area

    Science.gov (United States)

    Gonzales, Patricia; Ajami, Newsha; Sun, Yujie

    2017-09-01

    Water utilities are increasingly relying on water efficiency and conservation to extend the availability of supplies. Despite spatial and institutional interdependency of many utilities, these demand-side management initiatives have traditionally been tackled by individual utilities operating in isolation. In this study, we introduce a policy framework for water conservation credits that enables collaboration at the regional scale. Under the proposed approach, utilities have the flexibility to invest in water conservation measures that are appropriate for their specific service area. When utilities have insufficient capacity for local cost-effective measures, they may opt to purchase credits, contributing to fund subsidies for utilities that do have that capacity and can provide the credits, while the region as a whole benefits from more reliable water supplies. This work aims to provide insights on the potential impacts of a water conservation credit policy framework when utilities are given the option to collaborate in their efforts. We model utility decisions as rational cost-minimizing actors subject to different decision-making dynamics and water demand scenarios, and demonstrate the institutional characteristics needed for the proposed policy to be effective. We apply this model to a counterfactual case study of water utility members of the Bay Area Water Supply and Conservation Agency in California during the drought period of June 2015 to May 2016. Our scenario analysis indicates that when the institutional structure and incentives are appropriately defined, water agencies can achieve economic benefits from collaborating in their conservation efforts, especially if they coordinate more closely in their decision-making.

  20. The Holocene history of Nares Strait: Transition from glacial bay to Arctic-Atlantic throughflow

    Science.gov (United States)

    Jennings, Anne E.; Sheldon, Christina; Cronin, Thomas M.; Francus, Pierre; Stoner, Joseph; Andrews, John

    2011-01-01

    Retreat of glacier ice from Nares Strait and other straits in the Canadian Arctic Archipelago after the end of the last Ice Age initiated an important connection between the Arctic and the North Atlantic Oceans, allowing development of modern ocean circulation in Baffin Bay and the Labrador Sea. As low-salinity, nutrient-rich Arctic Water began to enter Baffin Bay, it contributed to the Baffin and Labrador currents flowing southward. This enhanced freshwater inflow must have influenced the sea ice regime and likely is responsible for poor calcium carbonate preservation that characterizes the Baffin Island margin today. Sedimentologic and paleoceanographic data from radiocarbon-dated core HLY03-05GC, Hall Basin, northern Nares Strait, document the timing and paleoenvironments surrounding the retreat of waning ice sheets from Nares Strait and opening of this connection between the Arctic Ocean and Baffin Bay. Hall Basin was deglaciated soon before 10,300 cal BP (calibrated years before present) and records ice-distal sedimentation in a glacial bay facing the Arctic Ocean until about 9,000 cal BP. Atlantic Water was present in Hall Basin during deglaciation, suggesting that it may have promoted ice retreat. A transitional unit with high ice-rafted debris content records the opening of Nares Strait at approximately 9,000 cal BP. High productivity in Hall Basin between 9,000 and 6,000 cal BP reflects reduced sea ice cover and duration as well as throughflow of nutrient-rich Pacific Water. The later Holocene is poorly resolved in the core, but slow sedimentation rates and heavier carbon isotope values support an interpretation of increased sea ice cover and decreased productivity during the Neoglacial period.