Science.gov

Sample records for melah lagoon ne

  1. Coastal Evolution in a Mediterranean Microtidal Zone: Mid to Late Holocene Natural Dynamics and Human Management of the Castelló Lagoon, NE Spain

    PubMed Central

    Ejarque, Ana; Julià, Ramon; Reed, Jane M.; Mesquita-Joanes, Francesc; Marco-Barba, Javier; Riera, Santiago

    2016-01-01

    We present a palaeoenvironmental study of the Castelló lagoon (NE Spain), an important archive for understanding long-term interactions between dynamic littoral ecosystems and human management. Combining geochemistry, mineralogy, ostracods, diatoms, pollen, non-pollen palynomorphs, charcoal and archaeo-historical datasets we reconstruct: 1) the transition of the lagoon from a marine to a marginal environment between ~3150 cal BC to the 17th century AD; 2) fluctuations in salinity; and 3) natural and anthropogenic forces contributing to these changes. From the Late Neolithic to the Medieval period the lagoon ecosystem was driven by changing marine influence and the land was mainly exploited for grazing, with little evidence for impact on the natural woodland. Land-use exploitation adapted to natural coastal dynamics, with maximum marine flooding hampering agropastoral activities between ~1550 and ~150 cal BC. In contrast, societies actively controlled the lagoon dynamics and become a major agent of landscape transformation after the Medieval period. The removal of littoral woodlands after the 8th century was followed by the expansion of agrarian and industrial activities. Regional mining and smelting activities polluted the lagoon with heavy metals from the ~11th century onwards. The expansion of the milling industry and of agricultural lands led to the channelization of the river Muga into the lagoon after ~1250 cal AD. This caused its transformation into a freshwater lake, increased nutrient load, and the infilling and drainage of a great part of the lagoon. By tracking the shift towards an anthropogenically-controlled system around ~750 yr ago, this study points out Mediterranean lagoons as ancient and heavily-modified systems, with anthropogenic impacts and controls covering multi-centennial and even millennial timescales. Finally, we contributed to the future construction of reliable seashell-based chronologies in NE Spain by calibrating the Banyuls-sur-Mer

  2. Coastal Evolution in a Mediterranean Microtidal Zone: Mid to Late Holocene Natural Dynamics and Human Management of the Castelló Lagoon, NE Spain.

    PubMed

    Ejarque, Ana; Julià, Ramon; Reed, Jane M; Mesquita-Joanes, Francesc; Marco-Barba, Javier; Riera, Santiago

    2016-01-01

    We present a palaeoenvironmental study of the Castelló lagoon (NE Spain), an important archive for understanding long-term interactions between dynamic littoral ecosystems and human management. Combining geochemistry, mineralogy, ostracods, diatoms, pollen, non-pollen palynomorphs, charcoal and archaeo-historical datasets we reconstruct: 1) the transition of the lagoon from a marine to a marginal environment between ~3150 cal BC to the 17th century AD; 2) fluctuations in salinity; and 3) natural and anthropogenic forces contributing to these changes. From the Late Neolithic to the Medieval period the lagoon ecosystem was driven by changing marine influence and the land was mainly exploited for grazing, with little evidence for impact on the natural woodland. Land-use exploitation adapted to natural coastal dynamics, with maximum marine flooding hampering agropastoral activities between ~1550 and ~150 cal BC. In contrast, societies actively controlled the lagoon dynamics and become a major agent of landscape transformation after the Medieval period. The removal of littoral woodlands after the 8th century was followed by the expansion of agrarian and industrial activities. Regional mining and smelting activities polluted the lagoon with heavy metals from the ~11th century onwards. The expansion of the milling industry and of agricultural lands led to the channelization of the river Muga into the lagoon after ~1250 cal AD. This caused its transformation into a freshwater lake, increased nutrient load, and the infilling and drainage of a great part of the lagoon. By tracking the shift towards an anthropogenically-controlled system around ~750 yr ago, this study points out Mediterranean lagoons as ancient and heavily-modified systems, with anthropogenic impacts and controls covering multi-centennial and even millennial timescales. Finally, we contributed to the future construction of reliable seashell-based chronologies in NE Spain by calibrating the Banyuls-sur-Mer

  3. Exceptionally preserved insect fossils in the Late Jurassic lagoon of Orbagnoux (Rhône Valley, France)

    PubMed Central

    Nel, Patricia; Krieg-Jacquier, Régis; Pouillon, Jean-Marc

    2014-01-01

    The Late Kimmeridgian marine limestones of the area around Orbagnoux (Rhône, France) are well known for their fish fauna and terrestrial flora. Here we record the first insects and their activities (mines on leaves and trails in sediments) from these layers, including the oldest record of the gerromorphan bugs, as a new genus and species Gallomesovelia grioti, attributed to the most basal family Mesoveliidae and subfamily Madeoveliinae. These new fossils suggest the presence of a complex terrestrial palaeoecosystem on emerged lands near the lagoon where the limestones were deposited. The exquisite state of preservation of these fossils also suggests that these outcrops can potentially become an important Konservat-Lagerstätte for the Late Jurassic of Western Europe. PMID:25210652

  4. Pyrite as a proxy for the identification of former coastal lagoons in semiarid NE Brazil

    NASA Astrophysics Data System (ADS)

    Ferreira, Tiago O.; Nóbrega, Gabriel N.; Albuquerque, Antonia G. B. M.; Sartor, Lucas R.; Gomes, Irlene S.; Artur, Adriana G.; Otero, Xosé L.

    2015-10-01

    This work aimed to test the suitability of pyrite (FeS2) as a proxy for reconstructing past marine environmental conditions along the semiarid coast of Brazil. Morphological description combined with physicochemical analyses including Fe partitioning were conducted for soil depth profiles (30 and 60 cm depths) at three sites in two contrasting lagoons of the state of Ceará: a suspected former lagoon that would have been transformed into a freshwater "lake" at a site vegetated by Juncus effusus (site P1), and another lagoon with connection to the sea at sites vegetated by J. effusus (site P2) or Portulaca oleracea (site P3). Soil samples were collected in September 2010. Site P3 had more reducing conditions, reaching Eh values of -132 mV in the surface layer (0-10 cm), whereas minimum values for the P1 and P2 sites were +219 and +85 mV, respectively. Lower pyritic Fe values were found at site P1, with a degree of pyritization (DOP) ranging from 10 to 13%. At sites P2 and P3, DOP ranged from 9 to 67% and from 55 to 72%, respectively. These results are consistent with an interruption of tidal channels by eolian dune migration inducing strong changes in the hydrodynamics and physicochemical characteristics (lower salinity, oxidizing conditions) of these sites, causing the dieback of suspected former mangroves and a succession to freshwater marshes with an intermediate salt marsh stage. Together with other physicochemical signatures, pyrite can evidently serve as a useful proxy in tracking environmental changes in such ecotones, with implications for coastal management.

  5. Factors responsible for rapid dissipation of acidic herbicides in the coastal lagoons of the Camargue (Rhône River Delta, France).

    PubMed

    Al Housari, Fadi; Höhener, Patrick; Chiron, Serge

    2011-01-01

    This study was aimed at investigating which processes cause acidic herbicides (e.g., bentazone, MCPA and dichlorprop) to rapidly disappear in the lagoons of the Rhône delta, which are peculiar brackish and shallow aquatic environments. The use of the model MASAS (Modeling of Anthropogenic Substances in Aquatic Systems) revealed that sorption, sedimentation, volatilization, flushing and abiotic hydrolysis had a minor role in the attenuation of the investigated herbicides. Laboratory scale biodegradation and photodegradation studies were conducted to better assess the significance of these two processes in the natural attenuation of herbicides in brackish (lagoons) waters with respect to fresh waters (canals draining paddy fields). Herbicide biodegradation rates were significantly lower in lagoon water than in canal water. Consequently, photodegradation was the main dissipation route of all investigated herbicides. The contribution of indirect photolysis was relevant for MCPA and dichlorprop while direct photolysis dominated for bentazone removal. There is a need to further investigate the identity of phototransformation products of herbicides in lagoons.

  6. Evaluation of sediment contamination by monoaromatic hydrocarbons in the coastal lagoons of Gulf of Saros, NE Aegean Sea.

    PubMed

    Ünlü, Selma; Alpar, Bedri

    2017-03-19

    The concentrations and distribution of monoaromatic hydrocarbons (benzene, toluene, ethyl benzene and the sum of m-, p- and o-, xylenes) were determined in the sediments of coastal lagoons of the Gulf of Saros, using a static headspace GC-MS. The total concentrations of BTEX compounds ranged from 368.5 to below detection limit 0.6μgkg(-1) dw, with a mean value of 61.5μgkg(-1) dw. The light aromatic fraction of m-, p-xylene was the most abundant compound (57.1% in average), and followed by toluene (38.1%)>ethylbenzene (4.1%)>o-xylene (2.5%)>benzene (1.1%). The factor analysis indicated that the levels and distribution of BTEX compounds depend on the type of contaminant source (mobile/point), absorbance of compounds in sediment, and mobility of benzene compound and degradation processes. Point sources are mainly related to agricultural facilities and port activities while the dispersion of compounds are related with their solubility, volatility and effect of sea/saline waters on lagoons.

  7. Zooplankton taxonomic and size diversity in Mediterranean coastal lagoons (NE Iberian Peninsula): Influence of hydrology, nutrient composition, food resource availability and predation

    NASA Astrophysics Data System (ADS)

    Badosa, Anna; Boix, Dani; Brucet, Sandra; López-Flores, Rocío; Gascón, Stéphanie; Quintana, Xavier D.

    2007-01-01

    The influence of hydrology, nutrient composition, food resource availability and predation on zooplankton taxonomic and size diversity was analyzed in several shallow lagoons of a Mediterranean salt marsh (Baix Ter Wetlands, NE Iberian Peninsula). Taxonomic diversity correlated better with variables related to the trophic state, such as nutrient concentrations, whereas size diversity was more sensitive to fish predation. However, the fish predation influence on the size diversity was only significant when fishes reached high densities. Under low fish densities no predation effects were observed and the food resource availability (FR a) appeared to be more important in structuring the zooplankton community. Nevertheless, the two diversity indexes showed opposite responses to this factor. With increasing FR a the taxonomic diversity increased and the size diversity decreased. Neither taxonomic nor size diversity of the zooplankton community correlated with other physical or biotic factors such as hydrological variability or macroinvertebrate predation. The relationships found suggest that the size diversity is mainly related to biotic interactions, such as fish predation or inter/intraspecific competition, while the taxonomic diversity appears to be more sensitive to abiotic factors such as the nutrient composition.

  8. Upper Cretaceous and lower Paleogene benthic foraminiferal paleoecology from north-eastern Tunisia: El Melah section

    NASA Astrophysics Data System (ADS)

    Gallala, N.; Zaghbib-Turki, D.; Turki, M. M.; Arenillas, I.; Arz, J. A.; Molina, E.

    2009-04-01

    As an impact of the bolide and ejecta falls at the K/Pg boundary the planktonic Foraminifera have suffered sever mass extinction. However, no small Benthic Foraminifera species mass extinction at the K/Pg boundary has documented. Nevertheless many species have showed disturbance. The Maastrichtian assemblages may be different from those of the lower Paleogene by their species content, diversity and frequencies. At the El Melah section, the small benthic foraminifera indicate upper bathyal environment, and manifest significant faunal turnover. Until the uppermost Maastrichtian, their assemblages are highly diversified, with 109 species. They are dominated by endobenthic morphotypes (72 %). At the K/Pg boundary, although 34% of them seem to disappear, but only few species have really extinct such us Arenobulimina obesa. Nevertheless, the majority of species persist elsewhere at the Danian (e.g. Gaudryina aissana, Gaudryina inflata, Tritaxia midwayensis, Coryphostoma incrassata). At the lower Danian, the survivor Maastrichtian species are of 66%. Some of them disappeared temporary. Three survivor species were eclipsed during the Guembelitria cretacea zone (Globobulimina ovata, Praebulimina carseyae and Anomalinoides welleri) and 27 other species were diminished during the Parvularugoglobigerina eugubina subzone. They are composed of both calcareous fauna (e.g. Bulimina rugifera, Bolivina deccurens, Anomalinoides midwayensis, Dentalina colei, Marginulina cf. glabra) and agglutinated fauna (e.g. Spiroplectamina knebeli and Saccamina placenta). Throughout the Parasubbotina pseudobulloides subzone, 15 others species were progressively disappeared. They are oligotrophic and low oxygen tolerant. About the Masstrichtian species Gaudryina inflata, G. pyramidata and Tritaxia midwayensis. These species seem to be more trophic exigent.Besides, at the lower Danian, 27 species seems to be appeared. Few of them appeared really (e.g. Spiroplectamina dentata, Dentalina vertebralis

  9. Acid-labile sulfides in shallow marine bottom sediments: A review of the impact on ecosystems in the Azov Sea, the NE Black Sea shelf and NW Adriatic lagoons

    NASA Astrophysics Data System (ADS)

    Sorokin, Yu. I.; Zakuskina, O. Yu

    2012-02-01

    Acid-labile sulfides (LS) increase in bottom sediments at sites in the Azov Sea, at the NE Black Sea shelf and in the coastal lagoons of NW Adriatic Sea experiencing direct impacts of anthropogenic pollution. Fresh anthropogenic organic matter stimulates the bacterial sulfate reduction and here the rate of the LS production overcomes their loss during the oxidation and pyritization. This results in the expansion of reduced sediment layer up to the bottom surface. The LS concentration in the reduced sediments varies between 300 and 2000 mg S l -1 of wet silt depending on the size of pollution loading and on the rate of sedimentation. In the oxidized sediments away from the direct pollution impact, the LS concentration did not exceed 100-150 mg S l -1. Being a strong cytochrome toxin, the LS adversely affect the coastal ecosystems. The concentrations over 600 mg S l -1 result in quasi total benthic mortality whereas >300-400 mg S l -1 depletes the benthic faunal abundance and taxonomic diversity. Accumulation of the LS in sediments also induces nocturnal hypoxia and stimulates domination of toxic cyanobacteria in the pelagic phytocenoses.

  10. Diversity and Enzymatic Profiling of Halotolerant Micromycetes from Sebkha El Melah, a Saharan Salt Flat in Southern Tunisia

    PubMed Central

    Jaouani, Atef; Neifar, Mohamed; Prigione, Valeria; Ayari, Amani; Sbissi, Imed; Ben Amor, Sonia; Ben Tekaya, Seifeddine; Varese, Giovanna Cristina; Cherif, Ameur; Gtari, Maher

    2014-01-01

    Twenty-one moderately halotolerant fungi have been isolated from sample ashes collected from Sebkha El Melah, a Saharan salt flat located in southern Tunisia. Based on morphology and sequence inference from the internal transcribed spacer regions, 28S rRNA gene and other specific genes such as β-tubulin, actin, calmodulin, and glyceraldehyde-3-phosphate dehydrogenase, the isolates were found to be distributed over 15 taxa belonging to 6 genera of Ascomycetes: Cladosporium (n = 3), Alternaria (n = 4), Aspergillus (n = 3), Penicillium (n = 5), Ulocladium (n = 2), and Engyodontium (n = 2). Their tolerance to different concentrations of salt in solid and liquid media was examined. Excepting Cladosporium cladosporioides JA18, all isolates were considered as alkali-halotolerant since they were able to grow in media containing 10% of salt with an initial pH 10. All isolates were resistant to oxidative stresses and low temperature whereas 5 strains belonging to Alternaria, Ulocladium, and Aspergillus genera were able to grow at 45°C. The screening of fungal strains for sets of enzyme production, namely, cellulase (CMCase), amylase, protease, lipase, and laccase, in presence of 10% NaCl, showed a variety of extracellular hydrolytic and oxidative profiles. Protease was the most abundant enzyme produced whereas laccase producers were members of the genus Cladosporium. PMID:25136587

  11. Diversity and enzymatic profiling of halotolerant micromycetes from Sebkha El Melah, a Saharan salt flat in southern Tunisia.

    PubMed

    Jaouani, Atef; Neifar, Mohamed; Prigione, Valeria; Ayari, Amani; Sbissi, Imed; Ben Amor, Sonia; Ben Tekaya, Seifeddine; Varese, Giovanna Cristina; Cherif, Ameur; Gtari, Maher

    2014-01-01

    Twenty-one moderately halotolerant fungi have been isolated from sample ashes collected from Sebkha El Melah, a Saharan salt flat located in southern Tunisia. Based on morphology and sequence inference from the internal transcribed spacer regions, 28S rRNA gene and other specific genes such as β-tubulin, actin, calmodulin, and glyceraldehyde-3-phosphate dehydrogenase, the isolates were found to be distributed over 15 taxa belonging to 6 genera of Ascomycetes: Cladosporium (n = 3), Alternaria (n = 4), Aspergillus (n = 3), Penicillium (n = 5), Ulocladium (n = 2), and Engyodontium (n = 2). Their tolerance to different concentrations of salt in solid and liquid media was examined. Excepting Cladosporium cladosporioides JA18, all isolates were considered as alkali-halotolerant since they were able to grow in media containing 10% of salt with an initial pH 10. All isolates were resistant to oxidative stresses and low temperature whereas 5 strains belonging to Alternaria, Ulocladium, and Aspergillus genera were able to grow at 45°C. The screening of fungal strains for sets of enzyme production, namely, cellulase (CMCase), amylase, protease, lipase, and laccase, in presence of 10% NaCl, showed a variety of extracellular hydrolytic and oxidative profiles. Protease was the most abundant enzyme produced whereas laccase producers were members of the genus Cladosporium.

  12. Lagoons and Oxidation Ponds.

    ERIC Educational Resources Information Center

    O'Brien, W. J.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers lagoons and oxidation ponds, and it includes some areas such as improving the effluents from ponds, stabilization ponds, aerated lagoons, and oxidation ditches. A list of 36 references is also presented. (HM)

  13. Brazil The Duck Lagoon

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Multi-angle Imaging SpectroRadiometer (MISR) image of Brazil covers an area of about 298 kilometers x 358 kilometers, and was captured by the instrument's vertical-viewing (nadir) camera on December 27, 2001. The 'Lagoa dos Patos', in the Brazilian state of Rio Grande do Sul, translates to 'the Duck Lagoon'. It was named by 16th century Jesuit settlers, who asked the King of Spain to grant them title to the lagoon so that they could breed ducks. The King consented, but revoked his edict when he discovered that the 'duck-pond' (measuring about 14,000 square kilometers) was one of the largest lagoonal systems in the world. Note the sediment plume emanating from the southern end of the lagoon. Sailors in the 16th century imagined this outlet to be the mouth of a large river. Early Portuguese explorers mistook the entrance to the lagoon for the mouth of a great river and called it the Rio Grande. A series of wave-like points and curls form 'cusps' on the inner shores of the lagoon. The lagoon's characteristics change with short-term tide-induced cyclic perturbations, and with longer term large scale meteorological conditions. The distinctive wavelike 'cusps' along the inner shores result from the circulation, erosion and accumulation of sediments driven by wind and tidal action. The El Nino Southern Oscillation (ENSO) circulation affects precipitation amount and continental runoff, thereby changing the contents of the lagoon waters. High rainfall and increased freshwater discharge during El Nino events correspond with elevated dissolved nutrient concentrations and increased phytoplankton growth. La Nina years are dry and the associated low rainfall reduces the freshwater recharge to the lagoon, causing an increase in salinity. Occasional blooms of toxic cyanobacteria (Microcystis aeruginosa), have been registered in the lagoon when nutrient concentrations are elevated. A number of reeds and grasses are important to the lagoon estuary, including widgeon grass

  14. Lockport Sewage Lagoon.

    ERIC Educational Resources Information Center

    Perry, John

    1995-01-01

    Describes a student initiated stewardship project that resulted in the transformation of a sewage lagoon near the school into a place to study nature. Contains a list of 20 things that discourage a successful stewardship project. (LZ)

  15. Brazil: Duck Lagoon

    Atmospheric Science Data Center

    2013-04-18

    ... in the lagoon during spring and summer. Although the lowland tapir (Tapirus terrestris) is found in some parts of Rio Grande do Sul, the Baird's tapir (Tapirus bairdii), is not distributed within the image area (it is ...

  16. Comparative oceanography of coastal lagoons

    NASA Technical Reports Server (NTRS)

    Kjerfve, Bjorn

    1986-01-01

    The hypothesis that physical lagoon characteristics and variability depend on the channel connecting the lagoon to the adjacent coastal ocean is evaluated. The geographical, hydrological, and oceanographic characteristics of 10 lagoon systems are described and analyzed; these oceanographic features are utilized to classify the lagoon systems. Choked lagoons (Laguna Joyuda, Coorong, Lake St.Lucia, Gippsland Lakes, Lake Songkla/Thale Luang/Thale Noi, and Lagoa dos Patos) are prevalent on coasts with high wave energy and low tidal range; restricted lagoons (Lake Pontchartrain and Laguna de Terminos) are located on low/medium wave energy coasts with a low tidal range; and leaky lagoons (Mississippi Sound and Belize Lagoon/Chetumal Bay) are connected to the ocean by wide tidal passes that transmit oceanic effects into the lagoon with a minimum of resistance. The data support the hypothesis that the nature of the connecting channel controls system functions.

  17. Odor control in lagoons.

    PubMed

    Zhang, X L; Yan, S; Tyagi, R D; Surampalli, R Y

    2013-07-30

    Lagoons are widely used in rural area for wastewater treatment; however, the odor problem has hampered its application. The root of odor emission from lagoons varies from one to another. The key of controlling the odor is to find out the cause and accordingly provide strategies. Various physical, chemical, and biological methods have been reported and applied for odor control. Physical technologies such as masking, capturing and sorption are often employed to mitigate the pressure from compliant while not to cut off the problem. Chemical technologies which act rapidly and efficiently in odor control, utilize chemicals to damage the odorant production root or convert odorant to odorless substances. Biological methods such as aeration, biocover and biofiltration control the odor by enhancing aerobic condition or developing methanogens in lagoon, and biologically decomposing the odorants. Comparing to physical and chemical methods, biological methods are more feasible.

  18. Lagoon Restoration Project: Final report

    SciTech Connect

    1995-03-01

    This project is a multiyear effort focusing on energy flow in the Palace of Fine Arts lagoon just outside the Exploratorium in San Francisco. Phase 1 was a pilot study to determine the feasibility of improving biological energy flow through the small freshwater lagoon, using the expertise and resources of an environmental artist in collaboration with museum biologists and arts department staff. The primary outcome of Phase 1 is an experimental fountain exhibit inside the museum designed by public artist Laurie Lundquist with Exploratorium staff. This fountain, with signage, functions both as a model for natural aeration and filtration systems and as a focal point for museum visitors to learn about how biological processes cycle energy through aquatic systems. As part of the study of the lagoon`s health, volunteers continued biweekly bird consus from March through September, 1994. The goal was to find out whether the poor water quality of the lagoon is affecting the birds. Limited dredging was undertaken by the city Parks and Recreation Department. However, a more peermanent solution to the lagoon`s ecological problems would require an ambitious redesign of the lagoon.

  19. The tale of four lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic lagoons are a common management practice in the Carolinas for the treatment of swine wastewater. Although these lagoons were once thought to be relatively simple; their physical, chemical, and biological processes are actually very sophisticated. To get a better understanding of the microb...

  20. Circulation in Enewetak Atoll lagoon

    SciTech Connect

    Atkinson, M.; Smith, S.V.; Stroup, E.D.

    1981-11-01

    Currents at Enewetak Atoll, Marshall Islands, were measured on the reef margins, in the channels, and in the lagoon. Lagoon circulation is dominated by wind-driven downwind surface flow and an upwind middepth return flow. This wind-driven flow has the characteristics of an Ekman spiral in an enclosed sea. Lagoon flushing is accomplished primarily by surf-driven water input over the windward (eastern) reefs and southerly drift out the South Channel. Mean water residence time is 1 month, while water entering the northern portion of the atoll takes about 4 months to exit.

  1. Biogeochemical Composition of Mediterranean Waters Outside Thau Lagoon

    NASA Astrophysics Data System (ADS)

    Souchu, P.; Gasc, A.; Cahet, G.; Vaquer, A.; Collos, Y.; Deslous-Paoli, J. M.

    1997-03-01

    Physicochemical characteristics (temperature, salinity, dissolved oxygen), nutrients (NO 3-, NO 2-, NH 4+, soluble reactive phosphorus, Si), dissolved organic matter with bacterial cell counts (DON, DOP, DOC, BACT) and particulate matter (POC, PON, Chl a) were measured weekly from January 1993 to March 1994 in Mediterranean surface waters, sampled 2·5 km offshore in Thau Lagoon (Sète, France). Waters outside the lagoon displayed salinity reductions below 29 which corresponded to flood periods of the Rhône River and/or to winds oriented in a southeasterly direction. Levels of nutrients were increased by the influence of the Rhône river plume. Concentrations of NO 3-and NH 4+were rather close to the theoretical dilution line, while SRP and Si seemed to be rapidly taken up along their dilution gradient, especially in spring. The influx of NO 3-enriched waters into the lagoon in October showed that the Rhône river plume can potentially fertilize this lagoon. The flux of nutrient from the Rhône River led to Chl amaxima above 4 μ g l -1in spring. The concentration of DOC and BACT reached peak values at the decay of the spring bloom and decreased to their lowest level afterwards, suggesting that primary production was an important source of DOC but also that DOC was repackaged in the microbial loop rather than being transported to deeper layers. Yearly averaged atomic C:N and C:P ratios in DOM were 15 and 1000, respectively, which probably compelled bacterioplankton to compete with phytoplankton for NH 4+and SRP. No influence of the Rhône River was observed during summer. This period was characterized by SRP, NO 3-and NO 2-concentrations below the limits of detection and by the lowest levels in DOC, DON, BACT and Chl a. However, NH 4+and DOP concentrations remained, respectively, above 0·3 and 0·15 μ M, and the summer period corresponded to oxygen supersaturation (up to 122%). These observations suggest the dominance of picophytoplanktonic communities with low

  2. Mosquito Lagoon environmental resources inventory

    NASA Technical Reports Server (NTRS)

    Provancha, Jane A.; Hall, Carlton R.; Oddy, Donna M.

    1992-01-01

    This document provides a synopsis of biotic and abiotic data collected in the Mosquito Lagoon area in relation to water quality. A holistic ecological approach was used in this review to allow for summaries of climate, land use, vegetation, geohydrology, water quality, fishes, sea turtles, wading birds, marine mammals, invertebrates, shellfish, and mosquito control. The document includes a bibliographic database list of 157 citations that have references to the Mosquito Lagoon, many of which were utilized in development of the text.

  3. Impact of a river flash flood on microbial carbon and nitrogen production in a Mediterranean Lagoon (Thau Lagoon, France)

    NASA Astrophysics Data System (ADS)

    Fouilland, E.; Trottet, A.; Bancon-Montigny, C.; Bouvy, M.; Le Floc'h, E.; Gonzalez, J.-L.; Hatey, E.; Mas, S.; Mostajir, B.; Nouguier, J.; Pecqueur, D.; Rochelle-Newall, E.; Rodier, C.; Roques, C.; Salles, C.; Tournoud, M.-G.; Vidussi, F.

    2012-11-01

    Over half of the total nitrogen, phosphorus, silicate and dissolved organic carbon (DOC) loading was discharged from the Vène River into the Thau Lagoon waters within the first five days of what was considered to be the autumn flash flood period. Such loads represented about 8% and 3% of the yearly averaged total nitrogen and phosphorus load in Thau Lagoon, respectively. Although this event affected >20% of the total lagoon volume, river trace metal loads contributed apparently only weakly to the increase in labile trace metal concentrations in the lagoon surface waters. Differences between theoretical dilution values and observed values were also noticed for phosphate, silicate and dissolved organic carbon (DOC) concentrations. DOC losses (10-50%) mainly through flocculation, together with the substantial increases in some metallic contaminants such as Zn (from 6 to >30 μg L-1) observed during the flash flood in saline lagoon waters, may have limited the carbon production of bacterial communities. The potential osmotic shock and the increase in turbidity may mainly explain the low phytoplankton C turnover rates (average of 0.02 h-1) measured in brackish waters (<30) during periods of heavy flood discharge. The dissolved inorganic nitrogen (DIN: NO3 + NH4) enrichment measured 12 days after the flash flood event in saline lagoon surface waters (from 22 to 143 μg N L-1) led to a substantial increase in phytoplanktonic C production and associated DIN uptake rates (from 2.6 to 7.0 μg C L-1 h-1 and from 0.5 to 1.1 μg N L-1 h-1, respectively). Subsequent accumulation in particulate organic carbon and nitrogen was not observed in the area studied during and after the flash flood period, averaging 549 ± 50 μg C L-1 and 168 ± 9 μg N L-1, respectively. This suggests that most of locally produced microbial production was rapidly filtered by oysters contributing to about 13% of the yearly exploited production in the lagoon and/or exported through sedimentation.

  4. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon...

  5. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon...

  6. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon...

  7. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon...

  8. 33 CFR 117.600 - Lagoon Pond.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lagoon Pond. 117.600 Section 117.600 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Massachusetts § 117.600 Lagoon Pond. The draw of the Lagoon...

  9. Metagenomes of Mediterranean coastal lagoons.

    PubMed

    Ghai, Rohit; Hernandez, Claudia Mella; Picazo, Antonio; Mizuno, Carolina Megumi; Ininbergs, Karolina; Díez, Beatriz; Valas, Ruben; DuPont, Christopher L; McMahon, Katherine D; Camacho, Antonio; Rodriguez-Valera, Francisco

    2012-01-01

    Coastal lagoons, both hypersaline and freshwater, are common, but still understudied ecosystems. We describe, for the first time, using high throughput sequencing, the extant microbiota of two large and representative Mediterranean coastal lagoons, the hypersaline Mar Menor, and the freshwater Albufera de Valencia, both located on the south eastern coast of Spain. We show there are considerable differences in the microbiota of both lagoons, in comparison to other marine and freshwater habitats. Importantly, a novel uncultured sulfur oxidizing Alphaproteobacteria was found to dominate bacterioplankton in the hypersaline Mar Menor. Also, in the latter prokaryotic cyanobacteria were almost exclusively comprised by Synechococcus and no Prochlorococcus was found. Remarkably, the microbial community in the freshwaters of the hypertrophic Albufera was completely in contrast to known freshwater systems, in that there was a near absence of well known and cosmopolitan groups of ultramicrobacteria namely Low GC Actinobacteria and the LD12 lineage of Alphaproteobacteria.

  10. Metagenomes of Mediterranean Coastal Lagoons

    PubMed Central

    Ghai, Rohit; Hernandez, Claudia Mella; Picazo, Antonio; Mizuno, Carolina Megumi; Ininbergs, Karolina; Díez, Beatriz; Valas, Ruben; DuPont, Christopher L.; McMahon, Katherine D.; Camacho, Antonio; Rodriguez-Valera, Francisco

    2012-01-01

    Coastal lagoons, both hypersaline and freshwater, are common, but still understudied ecosystems. We describe, for the first time, using high throughput sequencing, the extant microbiota of two large and representative Mediterranean coastal lagoons, the hypersaline Mar Menor, and the freshwater Albufera de Valencia, both located on the south eastern coast of Spain. We show there are considerable differences in the microbiota of both lagoons, in comparison to other marine and freshwater habitats. Importantly, a novel uncultured sulfur oxidizing Alphaproteobacteria was found to dominate bacterioplankton in the hypersaline Mar Menor. Also, in the latter prokaryotic cyanobacteria were almost exclusively comprised by Synechococcus and no Prochlorococcus was found. Remarkably, the microbial community in the freshwaters of the hypertrophic Albufera was completely in contrast to known freshwater systems, in that there was a near absence of well known and cosmopolitan groups of ultramicrobacteria namely Low GC Actinobacteria and the LD12 lineage of Alphaproteobacteria. PMID:22778901

  11. Metals in some lagoons of Mexico.

    PubMed Central

    Vazquez, F G; Sharma, V K; Alexander, V H; Frausto, C A

    1995-01-01

    The concentrations of metals, Cd, Cu, Fe, Mn, Ni, Pb, and Zn were determined in some lagoons to establish the level of metal pollution. The lagoons studied were Alvarado lagoon, Veracruz; San Andres lagoon, Tamaulipas; and Terminos lagoon, Campeche. The concentrations were determined in water, oyster (Crassostrea virginica), and sediments. Metals were accumulated in either oysters or sediments. Cu and Zn were higher in oysters and Fe and Mn were higher in sediments. The results in water samples were compared with the limit established by the Secretaria de Ecologia and Desarrollo Urbano Report and briefly discussed. PMID:7621796

  12. Metals in some lagoons of Mexico.

    PubMed

    Vazquez, F G; Sharma, V K; Alexander, V H; Frausto, C A

    1995-02-01

    The concentrations of metals, Cd, Cu, Fe, Mn, Ni, Pb, and Zn were determined in some lagoons to establish the level of metal pollution. The lagoons studied were Alvarado lagoon, Veracruz; San Andres lagoon, Tamaulipas; and Terminos lagoon, Campeche. The concentrations were determined in water, oyster (Crassostrea virginica), and sediments. Metals were accumulated in either oysters or sediments. Cu and Zn were higher in oysters and Fe and Mn were higher in sediments. The results in water samples were compared with the limit established by the Secretaria de Ecologia and Desarrollo Urbano Report and briefly discussed.

  13. Heavy metals distribution in sediments of Nador lagoon (Morocco)

    NASA Astrophysics Data System (ADS)

    Bloundi, K.; Duplay, J.

    2003-04-01

    The Nador lagoon is a paralic system, located North-East of Morocco. At the present time this ecosystem undergoes an anthropic stress induced by urban, industrial and agricultural releases, and also by fishery activity which enriches this ecosystem in organic and inorganic wastes. A geochemical study has been undertaken, first to define the areas contaminated by heavy metals (Zn, Cu, Co, Cr and V), and second to caracterize the different mineral phases, which trap these elements. Sediment samples were collected on twenty-eight stations scattered all over the lagoon, and each core (30 cm) was subdivided in two horizons (surface and depth). Mineralogical analyses as well as major and trace elements analyses were performed on surface and deep sediments. The results on major element analyses (Si, Al, Ca, Mg, Na, P) show an enrichment in halite and phosphates in the surface sediments. This highlights on one hand, low water exchange rates between the lagoon and the Mediterranean sea, and on the other hand, an increase in organic releases related to the urban, agricultural and fishery activities. The highest concentrations in inorganic micro-pollutant were recorded N-E of the lagoon and close to Nador city. With reference to the geochemical background, it can be concluded that there is a slight contamination in heavy metals. Moreover, enrichment factor calculations (EF) for heavy metals point out an increase in metal elements as following: Zn>Co>Cr>V>Cu. Sequential extractions were performed to determine the behaviour of these micro-pollutants. Thus, it was shown that carbonates, oxides and phosphates are the preferential mineral phases for trapping these heavy metals.

  14. Assessing the Impact of Animal Waste Lagoon Seepage on the Geochemistry of an Underlying Shallow Aquifer

    SciTech Connect

    McNab, W W; Singleton, M J; Moran, J E; Esser, B K

    2006-03-07

    Dairy facilities and similar confined animal operation settings pose a significant nitrate contamination threat via oxidation of animal wastes and subsequent transport to shallow groundwater. While nitrate contamination resulting from application of animal manure as fertilizer to fields is well recognized, the impact of manure lagoon leakage on groundwater quality is less well characterized. In this study, a dairy facility located in the southern San Joaquin Valley of California has been instrumented with monitoring wells as part of a two-year multidisciplinary study to evaluate nitrate loading and denitrification associated with facility operations. Among multiple types of data collected from the site, groundwater and surface water samples have been analyzed for major cations, anions, pH, oxidation-reduction potential, dissolved organic carbon, and selected dissolved gases (CO{sub 2}, CH{sub 4}, N{sub 2}, Ar, Ne). Modeling of putative geochemical processes occurring within the dairy site manure lagoons shows substantial off-gassing of CO{sub 2} and CH{sub 4} in response to mineralization of organic matter. The gas ebullition appears to strip dissolved gases, including Ar and Ne, from the lagoon water leaving concentrations that are undersaturated with respect to the atmosphere. The resulting fractionated dissolved gas signature serves as an effective tracer for the lagoon water in the underlying shallow groundwater and can be used to constrain inverse geochemical models that assess mixing fractions of lagoon water and local groundwater water. Together with ion exchange and mineral equilibria reactions, identification of lagoon seepage helps explain key attributes of the local groundwater chemistry, including input and cycling of nitrogen, across the site.

  15. Assessing confinement in coastal lagoons.

    PubMed

    Canu, Donata Melaku; Solidoro, Cosimo; Umgiesser, Georg; Cucco, Andrea; Ferrarin, Christian

    2012-11-01

    Measures of transport scale in aquatic systems can contribute to the formulation of definitions of indicators of the system's ecological properties. This paper addresses confinement, a specific transport scale proposed by biological scientists as a parameter that can capture and synthesize the principal properties that determine the spatial structure of biological communities in transitional environments. Currently, there is no direct experimental measure of confinement. In this study, a methodology based on the accumulation rate within a lagoon of a passive tracer of marine origin is proposed, the influences of different factors in the calculation of confinement are analyzed, and general recommendations are derived. In particular, we analyze the spatial and the temporal variability of confinement and its sensitivity to the seasonal variability of climatic forcing, the inputs from rivers and the parameterization of the tidal exchanges. The Lagoon of Venice is used as a case study.

  16. Sludge storage lagoon biogas recovery and use

    SciTech Connect

    Muller, D.; Norville, C. )

    1991-07-01

    The City of Memphis has two wastewater treatment plants. The SWTP employs two large anaerobic digestion sludge lagoons as part of the overall sludge treatment system. Although these lagoons are effective in concentrating and digesting sludge, they can generate offensive odors. The SWTP uses aerobic digesters to partially stabilize the sludge and help reduce objectionable odors before it enters the lagoons. The anaerobic digestion of sludge in the lagoons results in the dispersion of a large quantity of biogas into the atmosphere. The City realized that if the lagoons could be covered, the odor problem could be resolved, and at the same, time, biogas could be recovered and utilized as a source of energy. In 1987, the City commissioned ADI International to conduct a feasibility study to evaluate alternative methods of covering the lagoons and recovering and utilizing the biogas. The study recommended that the project be developed in two phases: (1) recovery of the biogas and (2) utilization of the biogas. Phase 1 consists of covering the two lagoons with an insulated membrane to control odor and temperature and collect the biogas. Phase 1 was found to be economically feasible and offered a unique opportunity for the City to save substantial operating costs at the treatment facility. The Memphis biogas recovery project is the only application in the world where a membrane cover has been used on a municipal wastewater sludge lagoon. It is also the largest lagoon cover system in the world.

  17. Denitrification enzyme activity in swine wastewater lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic lagoons are typically used for treatment of swine wastewater. Although these anaerobic lagoons were once thought to be relatively simple in their physical, chemical, and biological processes, they are actually very sophisticated. Recent reports of high levels of di-nitrogen emissions and h...

  18. The present environmental scenario of the Nador Lagoon (Morocco).

    PubMed

    Ruiz, F; Abad, M; Olías, M; Galán, E; González, I; Aguilá, E; Hamoumi, N; Pulido, I; Cantano, M

    2006-10-01

    In this paper, we present a multivariate approach (waters, sediments, microfauna) concerning the environmental state of the Nador Lagoon (NE Morocco). The normal water quality parameters (salinity, pH, nutrients) of the dominant marine flows are altered by local fecal water effluents, urban discharges, sewages derived from a water treatment station, and residues originated in a slaughterhouse. The geochemical analyses carried out in surficial sediment samples show very high concentrations of all metals studied near an old iron mine and moderate contents between Nador and its treatment station. Ostracods are good bioindicators of these environmental impacts, with the presence of a highly brackish assemblage in the quieter, more confined areas or the appearance of opportunistic species under hypoxic conditions. In addition, these microcrustaceans are absent in polluted bottom sediments or areas with high hydrodynamic gradients, whereas they decrease in both density and diversity if the subaerial exposure increases.

  19. Aerated Lagoons. Student Manual. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Andersen, Lorri

    This student manual contains the textual material for a unit which focuses on the structural and operationally unique features of aerated lagoons. Topic areas discussed include: (1) characteristics of completely mixed aerated lagoons; (2) facultative aerated lagoons; (3) aerated oxidation ponds; (4) effects of temperature on aerated lagoons; (5)…

  20. Nutrients and zooplankton composition and dynamics in relation to the hydrological pattern in a confined Mediterranean salt marsh (NE Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    Badosa, Anna; Boix, Dani; Brucet, Sandra; López-Flores, Rocío; Quintana, Xavier D.

    2006-02-01

    The role of the hydrological regime in the nutrients and zooplankton composition and dynamics has been analysed in five lagoons of La Pletera salt marshes (NE Iberian Peninsula) during a complete hydrological cycle (2002-2003). Two of the lagoons have their origin in the old river mouths while the other three were recently created in the framework of a Life Restoration project. This fact has also allowed us to study the effect of the lagoon age on nutrient and zooplankton composition and dynamics. The salt marsh hydrology is determined by a prolonged period of confinement without water inputs, irregularly interrupted by sudden water inputs due to flooding events (sea storms or intense rainfalls). While the dynamics of oxidized nitrogen compounds in the lagoons depends on the water inputs variability within each hydrological cycle, the internal load of phosphorus, total nitrogen and organic matter is related more to the cumulative mechanisms during the confinement periods. Accumulation processes may be easily related to lagoon age, since old lagoons have higher content of nutrients and organic matter, suggesting that these lagoons progressively accumulate nutrients during the successive confinement events. This is the usual case for most Mediterranean salt marshes without an artificially manipulated water regime. The zooplankton community in La Pletera integrates the effects of both the hydrological regime and the lagoon age since the former determines the temporal pattern of the main zooplankton species and the latter explains differences in composition and structure between old and new lagoons.

  1. Using hydrochemistry, tracers and isotopes to analyze hydrogeological dynamics and eutrophication processes in coastal lagoons

    NASA Astrophysics Data System (ADS)

    Menció, Anna; Mas-Pla, Josep; Quintana, Xavier D.

    2016-04-01

    Wetlands and coastal lagoons in Mediterranean areas have recently been the focus of an increasing interest due to the degradation of their ecological status in terms of declining biodiversity, alteration of ecological functioning and limitation of the ecosystem services they provide. Accordingly, the Horizon 2020 Programme of the European Union has set, as one of its priorities, to prevent a further degradation of these ecosystems and to recover their ecological functioning. The aim of this project is to analyze the hydrogeological dynamics in the Pletera coastal lagoons (NE, Spain) as a basis to propose guidelines for their sustainable management. Thus, monthly hydrochemical (with major ions, nutrients and tracers) and isotopic (δ18OH2O and δD) campaigns have been conducted, from November 2014 to October 2015, to determine the hydrogeological dynamics of the Pletera lagoons. In addition, in some of the sampling campaigns δ34SSO4, δ18OSO4, δ15NNO3 and δ18ONO3 have also been analyzed to determine the origin of eutrophication problems observed in these lagoons, mainly caused by nitrogen compounds. Project founded by MEC CGL-2014-57215-C4-2R and LIFE 13 NAT/ES/001001

  2. High performance aerated lagoon systems

    SciTech Connect

    Rich, L.

    1999-08-01

    At a time when less money is available for wastewater treatment facilities and there is increased competition for the local tax dollar, regulatory agencies are enforcing stricter effluent limits on treatment discharges. A solution for both municipalities and industry is to use aerated lagoon systems designed to meet these limits. This monograph, prepared by a recognized expert in the field, provides methods for the rational design of a wide variety of high-performance aerated lagoon systems. Such systems range from those that can be depended upon to meet secondary treatment standards alone to those that, with the inclusion of intermittent sand filters or elements of sequenced biological reactor (SBR) technology, can also provide for nitrification and nutrient removal. Considerable emphasis is placed on the use of appropriate performance parameters, and an entire chapter is devoted to diagnosing performance failures. Contents include: principles of microbiological processes, control of algae, benthal stabilization, design for CBOD removal, design for nitrification and denitrification in suspended-growth systems, design for nitrification in attached-growth systems, phosphorus removal, diagnosing performance.

  3. Sedimentation in lagoon waters (Case study on Segara Anakan Lagoon)

    NASA Astrophysics Data System (ADS)

    Sari, Lilik Kartika; Adrianto, Luky; Soewardi, Kadarwan; Atmadipoera, Agus S.; Hilmi, Endang

    2016-05-01

    This study aims to demonstrate the effect of sedimentation on waters area that serves as an advocate for life. It is included in the category to be wary considering these conditions will reduce the quality of life and threaten the life and survival of endemic biota. Observations rate of sedimentation since April 2014 until March 2015 performed at 6 stations that are considered to represent the condition of the lagoon. The observations for rate of sedimentation was conducted twice in a month for one year. Oceanographic parameters was taken by CTD (Conductivity, Temperature, and Depth) sensor in two seasons, at the height of the rainy season, March 2014 and August 2014. Results showed that the aquatic area more narrow characterized by changes in the outside line of the island visible on the image observation for two decades.

  4. Movement of lagoon-liquor constituents below four animal-waste lagoons.

    PubMed

    DeSutter, Tom M; Pierzynski, Gary M; Ham, Jay M

    2005-01-01

    Movement of liquor constituents from animal-waste lagoons has the potential to degrade ground water quality. The depth of movement and concentrations of lagoon-liquor constituents in the soil underlying three cattle (Bos taurus)-waste retention lagoons and one swine (Sus scrofa)-waste lagoon were determined. Samples were taken by using a direct-push coring machine, dissected by depth, and analyzed for total N, organic C, CaCO3, pH, cation exchange capacity (CEC), texture, and extractable NO3, NH(4), P, Cl, Ca, Mg, K, and Na. Ammonium N concentrations were greatest in the upper 0.5 m of soil under all four lagoons with concentrations ranging from 94 to 1139 mg kg(-1). Organic N was determined to make up between 39 and 74% of the total N beneath all lagoons. The swine lagoon had 2.4 kg N m(-2) in the underlying soil whereas the cattle lagoon with highest quantity of N had 1.2 kg N m(-2) in the underlying soil. Although N concentrations decreased with depth, N was greater than expected background levels at the bottom of some cores, indicating that the sampling efforts did not reach the bottom of the N plume. Nitrate N concentrations were generally less than 5 mg kg(-1) immediately below the lagoon floor. In the uppermost 0.5 m of soil underlying the swine and three cattle lagoons, NH4+ occupied 44% and between 1 and 22% of the soil cation exchange sites, respectively. The depth of movement of N under these lagoons, as much as 4 m, may pose remediation difficulties at lagoon closure.

  5. Lower Brule Lagoon System NPDES Permit

    EPA Pesticide Factsheets

    Under NPDES permit number SD-0020800, Lower Brule Rural Water is authorized to discharge from its wastewater lagoon system serving the town of Lower Brule, located in Lyman County, South Dakota, to the bank of the Missouri River (Lake Sharpe).

  6. Santa Margarita Lagoon Water Quality Monitoring Data

    DTIC Science & Technology

    2012-08-01

    potential eutrophication impairment. In particular, the Investigative Order directed the Santa Margarita Lagoon Stakeholder Group composed of Marine Corps...provide a long-term water quality dataset that can be used for calibrating a hydrodynamic and eutrophication numeric model of the lagoon. A secondary...objective of this project, to provide a long-term water quality dataset of sufficient quality for calibrating a hydrodynamic and eutrophication

  7. Flushing of a coastal lagoon in the Red Sea

    NASA Astrophysics Data System (ADS)

    Sultan, S. A. R.; Ahmad, F.

    1990-09-01

    Shu'aiba Lagoon (Lat. 20°45'N; Long. 39°28'E) is located on the eastern coast of the Red Sea. It is relatively shallow with an area of approximately 11·7 km 2. The inlet to the lagoon is narrow with a cross-sectional area of about 245 m 2. This lagoon is a future site to develop mariculture. With this objective in view the flushing time scale of the lagoon was calculated, as flushing is an important abiotic factor in lagoon ecology. The average flushing time for the months February to June and September to November is about 20 days. Oceanic inputs play an important part in the process of fertilization of the lagoons. The marine environment in arid zone lagoons is under natural stress due to high temperatures and salinities. However, the flushing time scale of 20 days may not exert intolerable stress on the ecology of the Shu'aiba Lagoon.

  8. The fate of Mediterranean lagoons under climate change

    NASA Astrophysics Data System (ADS)

    Umgiesser, Georg; Ferrarin, Christian; Cucco, Andrea; De Pascalis, Francesca; Ghezzo, Michol; Bellafiore, Debora; Bajo, Marco

    2014-05-01

    A numerical model (SHYFEM) has been applied to 10 Mediterranean lagoons and a comparison study between the lagoons has been carried out. The lagoons are the lagoons of Venice, Marano-Grado, Varano and Lesina in the Adriatic Sea, the Taranto basin in the Ionian Sea, the Cabras lagoon in Sardinia, and the lagoons of Ganzirri and Faro in Sicily, the Mar Menor in Spain and the Nador lagoon in Morocco. These lagoons give a representative picture of the lagoons situated around the Mediterranean basin. The lagoons range from a leaky type of lagoons to a choked type. The number of inlets ranges from just one in the Nador lagoon to 6 in the case of the Marano-Grado lagoons. Tidal range is from nano-tidal to micro-tidal. The depth ranges from an average depth of 1 m to up to 40 meters. The model is a finite element model, especially suited to shallow water basins with complicated geometric and morphologic variations. The model can compute the basic hydrodynamics, dispersion of tracers, temperature and salinity evolution, sediment transport and ecological parameters. Building on an earlier study that focused on the classification of Mediterranean lagoons based on hydrodynamics, exchange rates and renewal time, this study is concerned with the changes in physical parameters under climate change. Data from IPCC has been used to simulate the changes in renewal time, salinity and temperature of all lagoons, with respect to the control simulation. Whenever possible downscaled data for the Mediterranean basin have been used. Sea level rise scenarios are taken from the last IPCC report. The model has been applied in its 3D version and the chosen setup allows a comparison between results in the different lagoons. Results indicate that the differences of renewal time between all studied lagoons become smaller. This means that leaky lagoons become less leaky and choked lagoons less choked. What concerns temperature and salinity, changes occurring in the sea are amplified inside lagoons

  9. MiniBooNE

    SciTech Connect

    Mahn, Kendall Brianna Mcconnel; /Columbia U.

    2007-03-01

    MiniBooNE is a short baseline neutrino experiment designed to confirm or refute the LSND observed excess of electron anti neutrinos in a muon anti neutrino beam. The experimental setup, data samples, and oscillation fit method are discussed. Although the result was not public at the time of the talk, MiniBooNE has since published results, which are discussed briefly as well.

  10. Report to Congress: Municipal Wastewater Lagoon Study. Volume 1

    SciTech Connect

    Not Available

    1987-11-01

    This report presents the results of the Municipal Wastewater Lagoon Study performed by the USEPA in response to Section 3018 of RCRA and Sec. 246 of the Hazardous and Solid Waste amendments of 1984. The objectives are to determine: number and size of municipal lagoons; types and quantities of waste contained in such lagoons; the extent to which such waste has been or may be released from such lagoons and contaminates ground water; and available alternatives for preventing or controlling such releases.

  11. [Factors involved in coastal lagoons formation in Colombian southwest Caribbean].

    PubMed

    Alvarez-León, Ricardo; Mendoza-Mazzeo, Luis Alberto; Vernette, Georges

    2003-01-01

    Based on origin, geomorphological evolution and environmental characteristics, four of the main types of coastal lagoons were identified in colombian southwest Caribbean. The following are examples of each type: (1) Terrigenous sediment inputs in delta environment (Lagoons from Sinu River Delta, Cordoba Department), (2) Shore sand bars in coastal flat (Tesca Lagoon, Bolivar Deparment), (3) bar built by organisms such as coral reefs, (Isla Grande Lagoons, Bolivar Deparment) and, (4) bars controlled by tectonism (Cartagena Bay, Bolivar Deparment).

  12. Inverse-dispersion technique for assessing lagoon gas emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measuring gas emissions from treatment lagoons and storage ponds poses challenging conditions for existing micrometeorological techniques because of non-ideal wind conditions, such as those induced by trees and crops surrounding the lagoons, and lagoons with dimensions too small to establish equilib...

  13. Nitrifier activity and diversity in swine lagoon covers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia emissions from swine waste lagoons pose an environmental challenge to current pork production practices. Semi-permeable lagoon covers limit ammonia emissions by minimizing the effect of wind on the lagoon surface. Additionally, semi-permeable covers may also act as an attachment site for b...

  14. Accuracy of lagoon gas emissions using an inverse dispersion method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measuring gas emissions from treatment lagoons and storage ponds poses challenging conditions for existing micrometeorological techniques because of non-ideal wind conditions. These include those induced by trees and crops surrounding the lagoons, and lagoons with dimensions too small to establish ...

  15. Nutrient-Chlorophyll Relationships in the Indian River Lagoon, Florida

    EPA Science Inventory

    The Indian River Lagoon is a highly diverse estuary located along Florida’s Atlantic coast. The system is made up of the main stem and two side-lagoons: the Banana River and Mosquito Lagoon. We segmented the main stem into three sections based on spatial trends in water quality ...

  16. Facultative Lagoons. Student Manual. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Andersen, Lorri

    The textual material for a unit on facultative lagoons is presented in this student manual. Topic areas discussed include: (1) loading; (2) microbial theory; (3) structure and design; (4) process control; (5) lagoon start-up; (6) data handling and analysis; (7) lagoon maintenance (considering visual observations, pond structure, safety, odor,…

  17. Hydrodynamic Modeling of Diego Garcia Lagoon

    DTIC Science & Technology

    2014-08-01

    regime. Water level was measured at four locations spread out along the shoreline of the lagoon to capture possible changes in the timing of water...the top of the unit on the seafloor to the water surface (upward looking) in 1-m bins at a rate of once per minute for the entire 14 days. The ADCPs

  18. Comparison of the triple-point temperatures of 20Ne, 22Ne and normal Ne

    NASA Astrophysics Data System (ADS)

    Nakano, T.; Tamura, O.; Nagao, K.

    2013-09-01

    At the National Metrology Institute of Japan (NMIJ), the triple points of 20Ne and 22Ne were realized using modular sealed cells, Ec3Ne20 and Ec8Ne22, made by the Istituto Nazionale di Ricerca Metrologica (INRiM) in Italy. The difference of the triple-point temperatures of 20Ne and 22Ne was estimated by using the sub-range of standard platinum resistance thermometers (SPRTs) calibrated by NMIJ on the International Temperature Scale of 1990 (ITS-90). The melting curves obtained with the Ec3Ne20 and Ec8Ne22 cells show narrow widths (0.1 mK) over a wide range of the inverse of the melted fraction (1/F) from 1/F=1 to 1/F=10. The liquidus point Ttp estimated by the melting curves from F˜0.5 to F˜0.85 using the Ec8Ne22 is 0.146 29 (4) K higher than that using the Ec3Ne20 cell, which is in good agreement with that observed by INRiM using the same cells. After correction of the effect of impurities and other isotopes for Ec3Ne20 and Ec8Ne22 cells, the difference of Ttp between pure 20Ne and pure 22Ne is estimated to be 0.146 61 (4) K, which is consistent with the recent results reported elsewhere. The sub-ranges of SPRTs computed by using the triple point of 20Ne or 22Ne realized by the Ec3Ne20 cell or the Ec8Ne22 cell in place of the triple point of Ne for the defining fixed point of the ITS-90 are in good agreement with those realized on the basis of the ITS-90 at NMIJ within 0.03 mK, which is much smaller than the non-uniqueness and the sub-range inconsistency of SPRTs.

  19. Registration of NE Trailblazer C-1, NE Trailblazer C0, NE Trailblazer C2, NE Trailblazer C3, NE Trailblazer C4, and NE Trailblazer C5 Switchgrass Germplasms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    NE Trailblazer C-1 (GP-101, PI 672015), NE Trailblazer C0 (GP-100, PI 672014), NE Trailblazer C2 (GP-102, PI 672016), NE Trailblazer C3 (GP-103, PI 672017), NE Trailblazer C4 (GP-104, PI 672018), and NE Trailblazer C5 (GP-105, PI 672019) switchgrass (Panicum virgatum L.) germplasms were released by ...

  20. How climate change threats water resource: the case of the Thau coastal lagoon (Mediterranean Sea, France)

    NASA Astrophysics Data System (ADS)

    La Jeunesse, Isabelle; Sellami, Haykel; Cirelli, Claudia

    2014-05-01

    The latest reports of the intergovernmental panel on climate change explained that the Mediterranean regions are especially vulnerable to the impacts of climate change. These latest are expected to have strong impacts on the management of water resources and on regional economies. The aim of this paper is to discuss impacts of climate changes on the Thau case study in relation to the evolution of water balance, water uses and adaptation to climate change. The Thau coastal lagoon is located in the Mediterranean coast in south of France in the Languedoc-Roussillon Region. Economic activities are diverse from shellfish farming, fertilizers industries to agriculture and tourism. However, tourism and shellfish farming are of major importance for local economy. If tourism is mainly turned to the Sea coast, shellfishes grow within the lagoon and rely on water quality. Previous studies have demonstrated the link between the coastal lagoon water quality and inputs of freshwater from the catchment. Thus, changes in rainfalls, runoff and water balance would not only affect water uses but also water quality. Climate changes projections are presented following the implementation of 4 downscaled climatic models. Impacts on water balance are modelled with SWAT (Soil Water Assessment Tool) for 2041-2070 compared to the 1971-2000 reference period. The decrease of precipitations and water balance will impact discharges and thus decrease the freshwater inputs to the coastal lagoon. A study of water uses conducted in interactions with stakeholders within the Thau area has permitted to assess both current and evolution of water uses. It has revealed local water resources are depleting while water demand is increasing and is planned to continue to increase in the really near future. To prevent water scarcity events, mainly due to the climate change context, the Regional authorities have connected the catchment to the Rhône river to import water. The conclusion of this study is while

  1. Lagoons and oxidation ponds. [Wastewater treatment

    SciTech Connect

    George, D.B.

    1982-06-01

    A review of the literature on waste stabilization pond systems is presented. Factors such as wastewater temperature, and levels of heavy metals that affect the stability of the lagoons and oxidation ponds, and methods to upgrade stabilization pond effluent to meet state and federal effluent requirements are discussed. Model simulations utilized to predict the treatment efficiency of various waste stabilization pond geometries, and inlet and outlet configurations are reviewed. (KRM)

  2. Lagoonal deposits in the Upper Cretaceous Rock Springs Formation (Mesaverde Group), southwest Wyoming

    USGS Publications Warehouse

    Kirschbaum, M.A.

    1989-01-01

    Most paleogeographic reconstructions of the Rock Springs Formation show shorelines having lobate to arcuate deltas. These shorelines are oriented NE-SW, with the sea to the southeast. Brackish-water bodies are usually shown in interdistributary areas or associated with abandoned delta lobes, and are open to the sea. In this study, a sedimentary sequence 30-50 m thick is interpreted as interdeltaic deposits. Brackish-water deposits within the sequence are interpreted as interdeltaic lagoons rather than interdistributary bays. Three facies associations (units) are recognized in nine measured sections of the study interval. Unit A consists of interbedded sandstone, mudrock and coal which occur in both fining- and coarsening-upward sequences less than 10 m thick. Fining-upward sequences decrease in thickness and frequency upwards in unit A and are interpreted as distributary channels. Coarsening-upward sequences associated with the channels are interpreted as crevasse splays that filled lakes or interdistributary bays. In the upper part of the unit where only minor channels are present, the coarsening-upward sequences are interpreted as bay deltas. Unit B consists of fossiliferous silty shale and bioturbated sandy siltstone. A low-diversity fauna of bivalves, gastropods, ostracods and foraminifers indicates that brackish-water conditions existed. Unit B intertongues with unit A to the northwest and with unit C to the southeast, and is interpreted as lagoonal deposits. Unit C consists of crossbedded and burrowed sandstone in beds 0.5-9 m thick. Sandstones are laterally continuous in the southeast but become tabular bodies enclosed within unit B to the northwest. Laterally continuous sandstones are interpreted as shoreface deposits on the basis of multidirectional crossbeds, marine trace fossils and continuity. Tabular sandstones are interpreted as flood-tidal deltas on the basis of NW-oriented crossbeds, pinchouts to the northwest and enclosure within unit B. Scoured

  3. Computing the residence times in the Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Umgiesser, G.; Cucco, A.

    2003-04-01

    The Venice Lagoon is a shallow water body with a total area of about 500 km2. Three inlets govern the water exchanges between the Adriatic Sea and the Venice Lagoon. Water, entering and exiting through these channels during an entire tidal cycle, changes its biogeochemical and physical properties. The aim of this work is to investigate the Venice Lagoon circulation and to quantify the turn over time of the lagoon which mainly influences the water quality of the basin. The study has been carried out with a numerical model. The model computes the main hydrodynamic unknowns on a spatial domain that represents the Venice Lagoon and the Adriatic Sea with a finite element grid. The model considers as open boundary the line of Otranto channel in the southern Adriatic Sea and elsewhere as closed boundary the whole perimeter of the Adriatic Sea and Venice Lagoon. The model has been calibrated using the sea level data measured by more than twelve tide gauges located along the Adriatic Sea and inside the lagoon. The results obtained by the calibrated model have been validated with experimental data such as discharge data collected by botton mounted ADCP probes located at each inlet. The simulations take into account the tidal forcing and the different wind regimes. The instantaneous circulation and the residual current fields have been analyzed and the impact of the most important wind regimes on the circulation has been studied. The turn over time of the lagoon has been computed under different forcing conditions. A passive tracer only subjected to transport mechanism, has been released inside the lagoon. Resolving the time decaying of the tracer concentration for the whole area, the model computes the spatial distribution of the residence time in the basin. The results show that the re-import of water that previously exited the lagoon through the three inlets, plays an important role on the estimation of the turn over time of the lagoon thus influencing the water quality of

  4. Laboratory and Pilot Scale Evaluation of Coagulation, Clarification, and Filtration for Upgrading Sewage Lagoon Effluents.

    DTIC Science & Technology

    1980-08-01

    often forms mats upon the surface of a lagoon. Diatoms have been found in lagoons and Euglena and Chiamydomonas have been reported as the most... Euglena , and Chiorella developed. 34 Table 8 Algal Genera Present in Facultative Lagoons Month First Lagoon Second Lagoon Third Lagoon June Euglena Eug...lena Euglena Ch lamydomonas Chlamydomonas Chicanydomonas Scenedesmus Scenedesmus Scenedesmus ChioreZla Chiorela Chlorella Phacus Phacus Phacus Diatoms

  5. Sludge storage lagoon biogas recovery and use. Volume 2

    SciTech Connect

    Muller, D.; Norville, C.

    1991-07-01

    The City of Memphis has two wastewater treatment plants. The SWTP employs two large anaerobic digestion sludge lagoons as part of the overall sludge treatment system. Although these lagoons are effective in concentrating and digesting sludge, they can generate offensive odors. The SWTP uses aerobic digesters to partially stabilize the sludge and help reduce objectionable odors before it enters the lagoons. The anaerobic digestion of sludge in the lagoons results in the dispersion of a large quantity of biogas into the atmosphere. The City realized that if the lagoons could be covered, the odor problem could be resolved, and at the same, time, biogas could be recovered and utilized as a source of energy. In 1987, the City commissioned ADI International to conduct a feasibility study to evaluate alternative methods of covering the lagoons and recovering and utilizing the biogas. The study recommended that the project be developed in two phases: (1) recovery of the biogas and (2) utilization of the biogas. Phase 1 consists of covering the two lagoons with an insulated membrane to control odor and temperature and collect the biogas. Phase 1 was found to be economically feasible and offered a unique opportunity for the City to save substantial operating costs at the treatment facility. The Memphis biogas recovery project is the only application in the world where a membrane cover has been used on a municipal wastewater sludge lagoon. It is also the largest lagoon cover system in the world.

  6. Hydrogen Sulfide Emissions from Sow Farm Lagoons across Climates Zones.

    PubMed

    Grant, Richard H; Boehm, Matthew T; Lawrence, Alfred J; Heber, Albert J

    2013-11-01

    Hydrogen sulfide (HS) emissions were measured periodically over the course of 2 yr at three sow waste lagoons representing humid mesothermal (North Carolina, NC), humid microthermal (Indiana, IN), and semiarid (Oklahoma, OK) climates. Emissions were determined using a backward Lagrangian stochastic model in conjunction with line-sampled HS concentrations and measured turbulence. The median annual sow-specific (area-specific) lagoon emissions at the OK farm were approximately 1.6 g head [hd] d (5880 µg m s), whereas those at the IN and NC sow farms were 0.035 g hd d (130 µg m s), and 0.041 g hd d (260 µg m s), respectively. Hydrogen sulfide emissions generally increased with wind speed. The daily HS emissions from the OK lagoon were greatest during the first half of the year and decreased as the year progressed. Emissions were episodic at the NC and IN lagoons. The generally low emissions at the NC and IN lagoons were probably a result of significant populations of purple sulfur bacteria maintained in the humid mesothermal and humid microthermal climates. Most of the large HS emission events at the NC and IN lagoons appeared to be a result of either precipitation events or liquid pump-out events. The high emissions at the OK lagoon in a semiarid climate were largely a result of high wind speeds enhancing both lagoon and air boundary layer mixing. The climate (air temperature, winds, and precipitation) appeared to influence the HS emissions from lagoons.

  7. Lagoon Seepage Testing Report for Central Facilities Area (CFA) Sewage Lagoons at Idaho National Laboratory, Butte County, Idaho

    SciTech Connect

    Morrison, Bridger

    2014-09-01

    J-U-B ENGINEERS, Inc. (J-U-B) performed seepage tests on the CFA Wastewater Lagoons 1, 2, and 3 between August 26th and September 22nd, 2014. The lagoons were tested to satisfy the Idaho Department of Environmental Quality (DEQ) Rules (IDAPA 58.01.16) that require all lagoons be tested at a frequency of every 10 years and the Compliance Activity CA-141-03 in the DEQ Wastewater Reuse Permit for the CFA Sewage Treatment Plant (LA-000141-03). The lagoons were tested to determine if the average seepage rates are less than 0.25 in/day, the maximum seepage rate allowed for lagoons built prior to April 15, 2007. The average seepage rates were estimated for each lagoon and are given in Table-ES1. The average seepage rates for Lagoons 1 and 2 are less than the allowable seepage rate of 0.25 in/day. Lagoon 1 and 2 passed the seepage test and will not have to be tested again until the year 20241. However, the average seepage rate for Lagoon 3 appears to exceed the allowable seepage rate of 0.25 in/day which means the potential source for the excessive leakage should be investigated further.

  8. Submarine groundwater discharge into typical tropical lagoons: A case study in eastern Hainan Island, China

    NASA Astrophysics Data System (ADS)

    Wang, Xilong; Du, Jinzhou

    2016-11-01

    Assessing submarine groundwater discharge (SGD) into lagoons and bays can be helpful to understand biogeochemical processes, especially nutrient dynamics. In the present paper, radium (Ra) isotopes were used to quantify SGD in two typical tropical lagoons (Laoye Lagoon (LY Lagoon) and Xiaohai Lagoon (XH Lagoon)) of eastern Hainan Island, China. The Ra mass balance model provided evidence that SGD plays an important role in the hydrology of the LY Lagoon and the XH Lagoon, delivering average SGD fluxes of 1.7 × 106 (94 L m-2 d-1) and 1.8 × 106 (41 L m-2 d-1) m3 d-1, respectively. Tidal pumping was one of the important driving forces for SGD fluxes in the LY and the XH Lagoons. Tidal-driven SGD into the tidal channels of both lagoons can account for approximately 10% of the total SGD flux into the lagoons. In addition, the dissolved inorganic nutrient budgets were reassessed in the LY Lagoon and the XH Lagoon, which showed that SGD was the major source of nutrients entering the LY Lagoon and that the LY Lagoon behaved as a source for dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) and as a sink for dissolved silicate (DSi). Nutrient loads in the XH Lagoon were mainly derived from riverine inputs and SGD, and the XH Lagoon behaved as a source for DIP, but a sink for DIN and DSi.

  9. Are coastal lagoons physically or biologically controlled ecosystems? Revisiting r vs. K strategies in coastal lagoons and estuaries

    NASA Astrophysics Data System (ADS)

    Pérez-Ruzafa, Angel; Marcos, Concepción; Pérez-Ruzafa, Isabel María; Pérez-Marcos, María

    2013-11-01

    Environmental stress influences biological assemblages, with species responding to stress by adopting particular life-history strategies (e.g., r vs. K). Coastal lagoons and estuaries are considered naturally stressed and physically controlled systems with frequent environmental disturbances and fluctuations. At the same time, their transitional nature (between terrestrial, freshwater and marine) makes them especially vulnerable to human impacts and land and freshwater inputs. As a result, it is hypothesised that residents of coastal lagoons would display characteristics of r-selected species. The r-strategy involves increased reproductive effort through early reproduction, small and numerous offspring with a large dispersive capability, short lifespan and small adult body size. Together, these traits provide a selective advantage in such unpredictable or short-lived environments. Alternatively, immigrants to coastal lagoons should mostly be K-strategists, with a competitive advantage over the r-strategists, at least on a temporary time scale. These hypotheses were explored using a dataset from 73 Atlanto-Mediterranean sites: 27 estuaries, 42 coastal lagoons and 4 from the sea, obtained from published sources. A detailed analysis of the distributions of the different resident fish species according to lagoon characteristics indicated that in lagoons with a higher marine influence the families Gobiidae, Blenniidae and Syngnathidae were common, while lagoons with freshwater influence are characterized by Cyprinidae and other freshwater species. In analyzing the biological strategies of lagoon species we found that fish assemblages inhabiting marine influenced lagoons were characterized by solitary, necto-benthonic sedentary species. These species are often hermaphroditic, with benthic broods and many exhibit brooding behaviour. This suggests that marine influenced lagoons are dominated by K-strategist species, while r-strategy species will be more common in

  10. Evaluating the human impact on groundwater quality discharging into a coastal reef lagoon

    NASA Astrophysics Data System (ADS)

    Rebolledo-Vieyra, M.; Hernandez-Terrones, L.; Soto, M.; Lecossec, A.; Monroy-Rios, E.

    2008-12-01

    The Eastern coast of the Yucatan Peninsula has the fastest growth rate in Mexico and groundwater is the only source of drinking water in the region. The consequences of the lack of proper infrastructure to collect and treat wastewater and the impact of human activities on the quality of groundwater are addressed. The groundwater in the coastal aquifer of Quintana Roo (SE Mexico) discharges directly into the ocean. In addition, the coral reef of the Eastern Yucatan Peninsula is part of the Mesoamerican Coral Reef System, one of the largest in the world. The interaction of the reef-lagoon hydraulics with the coastal aquifer of Puerto Morelos (NE Yucatan Peninsula), and a major input of NH4, SO4, SiO2, as a consequence of the use of septic tanks and the lack of modern wastewater treatment plants are presented. No seasonal parameters differences were observed, suggesting that groundwater composition reaching the reef lagoon is not changing seasonally. A conceptual model of the coastal aquifer was developed, in order to explain how the human activities are impacting directly on the groundwater quality that, potentially, will have a direct impact on the coral reef. The protection and conservation of coral reefs must be directly related with a policy of sound management of coastal aquifers and wastewater treatment.

  11. Clipperton, a possible future for atoll lagoons

    NASA Astrophysics Data System (ADS)

    Charpy, L.; Rodier, M.; Couté, A.; Perrette-Gallet, C.; Bley-Loëz, C.

    2010-09-01

    Closure of the Clipperton Island atoll (10°17' N 109°13' W), now a meromictic lake, is estimated to have occurred between 1839 and 1849. It was still closed in 2005. Brackish waters in the upper layer (0-10 m) were oxygenated, while saline waters in the deep layer (>20 m) were anoxic. Allowing for the methodological difficulties of earlier measurements, the physical characteristics of the lagoon did not seem to have changed significantly since the last expedition (1980). The intermediate layer between brackish and saline waters was characterized by a strong density gradient and a temperature inversion of up to 1.6°C. Microbial activity, water exchange between the deep layer and surrounding oceanic waters and the geothermal flux hypothesis are discussed. The low DIN and SRP concentrations observed in the upper layer, despite high nutrient input by seabird droppings, reflect the high nutrient uptake by primary producers as attested by the elevated overall gross primary production (6.6 g C m-2 day-1), and high suspended photosynthetic biomass (2.23 ± 0.23 μg Chl a l-1) and production (263 ± 27 μg C l-1 day-1). Phytoplankton composition changed in 67 years with the advent of new taxa and the disappearance of previously recorded species. The freshwater phytoplanktonic community comprised 43 taxa: 37 newly identified during the expedition and 6 previously noted; 16 species previously found were not seen in 2005. The closure of the lagoon, combined with the positive precipitation-evaporation budget characteristic of the region, has induced drastic changes in lagoon functioning compared with other closed atolls.

  12. Macroalgae, nutrient cycles, and pollutants in the lagoon of Venice

    SciTech Connect

    Sfriso, A.; Pavoni, B.; Marcomini, A.; Orio, A.A. )

    1992-12-01

    The Lagoon of Venice is a wide, shallow coastal basin that extends for about 50 km along the northwest coast of the Adriatic Sea. The lagoon has been substantially modified through the actions of man over the last century through the artificial control of the hydraulic dynamics of the lagoon including the construction of channels to facilitate navigation. The lagoon is subjected to considerable pollutant loading through the drainage of land under cultivation, municipal sewage, and industrial effluents. In this paper are reported the results of observations designed to document recent changes in macroalgal species composition, seasonal cycles of primary producers and nutrient levels, and the effects of the macroalgal community on concentrations of organic and inorganic pollutants. The dominant macroalgae in the lagoon was Ulva rigida, and the levels of plant nutrients and pollutants were influenced by the seasonal cycles of the macroalgal community. 44 refs., 11 figs., 2 tabs.

  13. Denitrification in anaerobic lagoons used to treat swine wastewater.

    PubMed

    Hunt, P G; Matheny, T A; Ro, K S; Vanotti, M B; Ducey, T F

    2010-01-01

    Anaerobic lagoons are commonly used for the treatment of swine wastewater. Although these lagoons were once thought to be relatively simple, their physical, chemical, and biological processes are very complex. This study of anaerobic lagoons had two objectives: (i) to quantify denitrification enzyme activity (DEA) and (ii) to evaluate the influence of lagoon characteristics on the DEA. The DEA was measured by the acetylene inhibition method. Wastewater samples and physical and chemical measurements were taken from the wastewater column of nine anaerobic swine lagoons from May 2006 to May 2009. These lagoons were typical for anaerobic swine lagoons in the Carolinas relative to their size, operation, and chemical and physical characteristics. Their mean value for DEA was 87 mg N2O-N m(-3) d(-1). In a lagoon with 2-m depth, this rate of DEA would be compatible with 1.74 kg N ha(-1) d(-1) When nonlimiting nitrate was added, the highest DEA was compatible with 4.38 kg N ha(-1) d(-1) loss. Using stepwise regression for this treatment, the lagoon characteristics (i.e., soluble organic carbon, total nitrogen, temperature, and NO3-N) provided a final step model R2 of 0.69. Nitrous oxide from incomplete denitrification was not a significant part of the system nitrogen balance. Although alternate pathways of denitrification may exist within or beneath the wastewater column, this paper documents the lack of sufficient denitrification enzyme activity within the wastewater column of these anaerobic lagoons to support large N2 gas losses via classical nitrification and denitrification.

  14. Sludge Lagoons. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Sharman, Ronald M.

    This lesson describes three different types of sludge lagoons: (1) drying lagoons; (2) facultative lagoons; and (3) anaerobic lagoons. Normal operating sequence and equipment are also described. The lesson is designed to be used in sequence with the complete Sludge Treatment and Disposal Course #166 or as an independent lesson. The instructor's…

  15. Impact of cross-reef water fluxes on lagoon dynamics: a simple parameterization for coral lagoon circulation model, with application to the Ouano Lagoon, New Caledonia

    NASA Astrophysics Data System (ADS)

    Chevalier, Cristele; Sous, Damien; Devenon, Jean-Luc; Pagano, Marc; Rougier, Gilles; Blanchot, Jean

    2015-11-01

    This manuscript presents a combined experimental and numerical study of the impact of cross-reef fluxes on coral reef lagoon dynamics. The selected field site is the Ouano Lagoon (New Caledonia Island, France) in the South Western Pacific Ocean. Measurements of wave transformation above the reef and current profiles through passages and reef openings have been carried out during a 3-month survey. Data analysis reveals the preponderant roles played by both tides and waves on the lagoon dynamics. Based on field data, a simple parameterization of cross-reef fluxes is implemented in a coastal lagoon circulation model and a satisfactory agreement is found between parameterized model and field results. The model is thus used as a numerical experimental tool in order to analyse the cross-reef flows' possible influence on a narrow lagoon dynamics. The results highlight the importance of cross-reef fluxes induced by wave breaking over the reef barrier on the whole lagoon circulation and water properties.

  16. Hypertrophic lagoon management by sediment disturbance.

    PubMed

    Lenzi, Mauro; Birardi, Francesca; Calzolai, Roberto; Finoia, Maria Grazia; Marcone, Francesco; Nocciolini, Stefano; Roffilli, Rugiada; Sgroi, Sergio; Solari, Duccio

    2010-01-01

    Experimental control of eutrophication in a small coastal lagoon was attempted by means of sediment disturbance. A specially designed boat was used to resuspend the top 3 cm of sediment by a jets of air-water directed towards the bottom. This disturbance was carried out for 3 months in each of two areas with a surface area of 24 and 20 hectares respectively. In a total of 80 stations in these two areas and in two undisturbed areas of 16 and 20 ha, organic matter, porosity, density and redox potential were monitored in sediment bimonthly and free sulphides were monitored in water close to the bottom. Before, during and after disturbance, the impact of daily sediment resuspension on the water column was monitored monthly, as ammonium nitrogen (N-NH4), soluble reactive phosphorus (SRP), dissolved oxygen (DO) and pH. In the whole lagoon, sediment texture was determined at the start and at the end of the experiment in 120 stations, and seaweed (mainly Chaetomorpha linum and Lophosiphonia subadunca) and seagrass (Ruppia cirrhosa) biomasses were estimated in 42 stations every month. The results showed a stable organic matter content in disturbed areas and an increase in undisturbed areas, as well as an increase in seaweed in areas distant from disturbed areas. No significant effect of sediment resuspension on water column N-NH4, SRP, DO or pH was found.

  17. KM3NeT

    SciTech Connect

    Jong, M. de; Collaboration: KM3NeT Collaboration

    2015-07-15

    KM3NeT is a large research infrastructure, that will consist of a network of deep-sea neutrino telescopes in the Mediterranean Sea. The main objective of KM3NeT is the discovery and subsequent observation of high-energy neutrino sources in the Universe. A further physics perspective is the measurement of the mass hierarchy of neutrinos. A corresponding study, ORCA, is ongoing within KM3NeT. A cost effective technology for (very) large water Cherenkov detectors has been developed based on a new generation of low price 3-inch photo-multiplier tubes. Following the successful deployment and operation of two prototypes, the construction of the KM3NeT research infrastructure has started. The prospects of the different phases of the implementation of KM3NeT are summarised.

  18. Both riverine detritus and dissolved nutrients drive lagoon fisheries

    NASA Astrophysics Data System (ADS)

    Bonthu, Subbareddy; Ganguly, Dipnarayan; Ramachandran, Purvaja; Ramachandran, Ramesh; Pattnaik, Ajit K.; Wolanski, Eric

    2016-12-01

    The net ecosystem metabolism in lagoons has often been estimated from the net budget of dissolved nutrients. Such is the case of the LOICZ estuarine biogeochemistry nutrient budget model that considers riverine dissolved nutrients, but not riverine detritus. However the neglect of detritus can lead to inconsistencies; for instance, it results in an estimate of 5-10 times more seaward export of nutrients than there is import from rivers in Chilika Lagoon, India. To resolve that discrepancy the UNESCO estuarine ecohydrology model, that considers both dissolved nutrients and detritus, was used and, for Chilika Lagoon, it reproduced successfully the spatial distribution of salinity, dissolved nutrients, phytoplankton and zooplankton as well as the fish yield data. Thus the model suggests that the riverine input of both detritus and dissolved nutrients supports the pelagic food web. The model also reproduces well the observation of decreased fish yield when the mouth of the lagoon was choked in the 1990s, demonstrating the importance of the physics that determine the flushing rate of waterborne matter. Thus, both farming in the watershed by driving the nutrient and detritus inputs to the lagoon, and dredging and engineering management of the mouth by controlling the flushing rate of the lagoon, have a major influence on fish stocks in the lagoon.

  19. Metals in sediments of San Andres lagoon, Tamaulipas, Mexico

    SciTech Connect

    Vazquez, F.G.; Aguilera, L.G. ); Sharma, V.K. )

    1994-03-01

    Heavy metal pollution in water is generally associated with industrial and municipal discharges into rivers, estuaries and lagoons. Once metals are in the water column, they may be taken up by organisms, deposited in the sediments or remain for some period in the water itself. The deposition rate in sediments depends on, among other factors, metal concentration in surface sediments. The concentrations of heavy metals in sediments of coastal, estuarine and lagoon environments have been determined by many workers. For the past several years, we have been interested in determining trace and heavy metal concentrations in the lagoons in Mexico to establish the levels of metal pollution. The work reported here is the completion of our ongoing study in San Andres lagoon. San Andres lagoon is located north of two industrial ports, Tampico and Altamira. In this industrial zone, the basins of the Panuco and Tamesi Rivers are localized and have industrial effluent throughout the year. All these activities and the input of the Tigre River, which runs through an agricultural and cattle-raising region, may affect the biogeochemistry of the San Andres lagoon. In the present work, we report concentrations of Cd, Co, Cu, Fe, Mn, Ni, Zn and Pb in sediments of San Andres lagoon. The measurements were made in different seasons; Rain-84 (August-September 1984); North (October-December 1984); Dry (April 1985); and Rain-85 (April-June 1985). 13 refs., 1 fig., 2 tabs.

  20. A Century of changes for Razelm-Sinoe Lagoon System

    NASA Astrophysics Data System (ADS)

    Scrieciu, Marian-Albert; Stanica, Adrian

    2014-05-01

    A Century of changes for Razelm-Sinoe Lagoon System Marian-Albert Scrieciu (a), Adrian Stanica (a) (a) National Institute of Marine Geology and Geoecology e GeoEcoMar, Str. Dimitrie Onciul 23e25, Sector 2, 024053 Bucharest, Romania Razelm-Sinoe Lagoon System, situated in the NW part of the Black Sea, in tight connection with the Danube Delta, has been subject to major changes due to human interventions in the past century. These changes have resulted into a complete change of the Lagoon specific ecosystems compared to its pristine state. In its natural state, as brackish - transitional environment, Antipa (1894) mentions Razelm Lagoon as one of the places with the greatest fisheries around the Black Sea coast (about 1879 - 1884, there were approximately 10,000 fishermen, all working on the Razelm Sinoe Lagoon System). Starting with the end of the XIXth Century, new canals were dug and existing channels were dredged in order to develop tighter connections with the Danube River. The natural inlet of Portita was blocked four decades ago and connections between the various parts of the lagoon system were controlled by the building of locks and sluices. The 2 inlets of Sinoe Lagoon were also controlled during early 1980s. Under these conditions, the lagoon ecosystem changed from brackish towards freshwater, with major effects on the existing flora and fauna. The period of brutal interventions ended in 1989 and the Razelm-Sinoe Lagoon System became part of the Danube Delta Biosphere Reserve in 1991, with a strict policy of nature protection and restoration. Spatial planning has been the major management option for the entire reserve, lagoon system included. Plans for sustainable development of the Razelm-Sinoe Lagoon System have been built in a participative manner, involving the local stakeholders, as part of FP7 ARCH project. Special attention has been given to impacts of climate change. The study presents the vision for the development Razelm-Sinoe Lagoon System over

  1. White pelicans swim in the lagoon

    NASA Technical Reports Server (NTRS)

    1999-01-01

    White pelicans search for a meal in the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The habitat of white pelicans are marshy lakes along the Pacific and Texas coasts, wintering chiefly in coastal lagoons such as this one. They often capture fish cooperatively, forming a long line, beating their wings and driving the prey into shallow water. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  2. Self-generated morphology in lagoon reefs.

    PubMed

    Blakeway, David; Hamblin, Michael G

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia's Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves-specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef.

  3. Self-generated morphology in lagoon reefs

    PubMed Central

    Hamblin, Michael G.

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia’s Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves—specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef. PMID:26175962

  4. Surface Water Quality Survey of Northern Indian River Lagoon from Sebastian Inlet to Mosquito Lagoon

    NASA Astrophysics Data System (ADS)

    Weaver, R. J.; Webb, B. M.

    2012-12-01

    Following news of an emerging brown tide algal bloom in the northern Indian River Lagoon (IRL), researchers sought to gain insight into the surface water quality in the IRL, as well as the extent of the algae coverage. A Portable SeaKeeper from YSI, mounted to a personal watercraft-based coastal profiling system, autonomously collected and analyzed the surface water. The system operates by recording sample data every 12 seconds while continuously underway at speeds up to and greater than 50 km/hr. The researchers covered a transect that started at Sebastian Inlet and followed a zig-zag path extending up through the Haulover Canal and into the Mosquito Lagoon. The survey path covered 166.7 km, and collected 2248 samples. Along the way stops were made at water quality stations used by the Saint John's River Water Management District, so that the data collected can be incorporated into ongoing monitoring efforts. The system analyzed the surface water for dissolved oxygen, pH, chlorophyll-a, salinity, temperature, turbidity, refined fuels, and CDOM. In the two days following the lagoon survey, the inlets at Port Canaveral and Sebastian were also surveyed for tidal currents and hydrography. The IRL transect survey data recorded evidence of the southern extent of the algae bloom in both chlorophyll-a and pH levels. Visual evidence of the bloom was striking as the water in the northern IRL turned a milk chocolaty brown color. Chlorophyll-a levels in the two inlets suggested bloom activity at these locations; however this bloom was different. This oceanic bloom was a result of a persistent upwelling event along the East Florida shelf, and the color was a paler green-yellow. The near-synoptic nature of the comprehensive lagoon survey, conducted in just over 7 hours, allows researchers to obtain a better understanding of water quality in coastal lagoons. Elevated levels of salinity, temperature, and refined fuels in the northern IRL indicate a low exchange rate and absence

  5. VISTA Stares Deeply into the Blue Lagoon

    NASA Astrophysics Data System (ADS)

    2011-01-01

    This new infrared image of the Lagoon Nebula was captured as part of a five-year study of the Milky Way using ESO's VISTA telescope at the Paranal Observatory in Chile. This is a small piece of a much larger image of the region surrounding the nebula, which is, in turn, only one part of a huge survey. Astronomers are currently using ESO's Visible and Infrared Survey Telescope for Astronomy (VISTA) to scour the Milky Way's central regions for variable objects and map its structure in greater detail than ever before. This huge survey is called VISTA Variables in the Via Lactea (VVV) [1]. The new infrared image presented here was taken as part of this survey. It shows the stellar nursery called the Lagoon Nebula (also known as Messier 8, see eso0936), which lies about 4000-5000 light-years away in the constellation of Sagittarius (the Archer). Infrared observations allow astronomers to peer behind the veil of dust that prevents them from seeing celestial objects in visible light. This is because visible light, which has a wavelength that is about the same size as the dust particles, is strongly scattered, but the longer wavelength infrared light can pass through the dust largely unscathed. VISTA, with its 4.1-metre diameter mirror - the largest survey telescope in the world - is dedicated to surveying large areas of the sky at near-infrared wavelengths deeply and quickly. It is therefore ideally suited to studying star birth. Stars typically form in large molecular clouds of gas and dust, which collapse under their own weight. The Lagoon Nebula, however, is also home to a number of much more compact regions of collapsing gas and dust, called Bok globules [2]. These dark clouds are so dense that, even in the infrared, they can block the starlight from background stars. But the most famous dark feature in the nebula, for which it is named, is the lagoon-shaped dust lane that winds its way through the glowing cloud of gas. Hot, young stars, which give off intense

  6. 13. Sewage treatment lagoon, drainage control at center left, looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Sewage treatment lagoon, drainage control at center left, looking south - Ellsworth Air Force Base, Delta Flight, Launch Control Facility, County Road CS23A, North of Exit 127, Interior, Jackson County, SD

  7. 1. Oblique view: east side, from Condado Lagoon Beach on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Oblique view: east side, from Condado Lagoon Beach on southeast (context) - Puente Guillermo Esteves, Spanning San Antonio Channel at PR-25 (Juan Ponce de Leon Avenue), San Juan, San Juan Municipio, PR

  8. ANALYSIS OF SWINE LAGOONS AND GROUND WATER FOR ENVIRONMENTAL ESTROGENS

    EPA Science Inventory

    A method was developed for analysis of low levels of natural (estradiol, estrone, estriol) and synthetic (ethinyl estradiol) estrogens in ground water and swine waste lagoon effluent. The method includes solid phase extraction of the estrogens, preparation of pentafluorobenzyl de...

  9. Nutrient removal from swine lagoon effluent by duckweed

    SciTech Connect

    Bergmann, B.A.; Cheng, J.; Classen, J.; Stomp, A.M.

    2000-04-01

    Three duckweed geographic isolates were grown on varying concentrations of swine lagoon effluent in a greenhouse to determine their ability to remove nutrients from the effluent. Duckweed biomass was harvested every other day over a 12-day period. Duckweed biomass production, nutrient loss from the swine lagoon effluent, and nutrient content of duckweed biomass were used to identify effluent concentrations/geographic isolate combinations that are effective in terms of nutrient utilization from swine lagoon effluent and production of healthy duckweed biomass. When Lemna minor geographic isolate 8627 was grown on 50% swine lagoon effluent, respective losses of TKN, NH{sub 3}-N, TP, OPO{sub 4}-P, TOC, K, Cu, and Zn were 83, 100, 49, 31, 68, 21, 28 and 67%.

  10. Seasonal variation in a tropical lagoon with submarine groundwater discharges

    NASA Astrophysics Data System (ADS)

    Tenorio, L.; Gómez-Valdés, J.; Enriquez, C.; Treviño, C.; Marino-Tapia, I.; López-Aguiar, K.

    2013-05-01

    The Chelem-Chuburna-Yucalpeten lagoon system is located at 21°17'N and 89°40'W in the Yucatan peninsula, Mexico. Temperature, conductivity, sea level, atmospheric pressure, solar radiation, and wind speed measurements were recorded in this lagoon, during various oceanographic surveys within 2010-2012. During the experiments, which included diurnal variations during spring and neap tidal cycles, CTD profiles were collected in 35 oceanographic stations and moored instruments were deployed at strategic locations. The aim of this work is to investigate transitions of thermohaline properties in a tropical lagoon with submarine groundwater discharges (SGDs) to increase the knowledge of the principal processes that control circulation and mixing in this kind of bodies of water. Results show that the lagoon is saltier than the ocean in the dry season and the opposite pattern is observed in the rain season. During the rain season could be more freshwater supplied from SGDs.

  11. Region 8 NPDES Lagoon General Permit Notice of Intent Form

    EPA Pesticide Factsheets

    Adobe Acrobat fillable form of the Notice of Intent for Coverage under the EPA Region 8 Lagoon General Permit for Wastewater Systems located in Indian Country in Colorado, Montana, North Dakota, South Dakota, Utah and Wyoming.

  12. ANALYSIS OF SWINE LAGOONS AND GROUND WATER FOR ENVIRONMENTAL ESTROGENS

    EPA Science Inventory

    A method was developed for analysis of low levels of natural (estradiol, estrone, estriol) and synthetic (ethynylestradiol) estrogens in ground water and swine waste lagoon effluent. The method includes solid phase extraction of the estrogens, preparation of pentafluorobenzyl der...

  13. Tidal dynamics in a frictionally dominated tropical lagoon

    NASA Astrophysics Data System (ADS)

    Tenorio-Fernandez, L.; Gomez-Valdes, J.; Marino-Tapia, I.; Enriquez, C.; Valle-Levinson, A.; Parra, S. M.

    2016-02-01

    This study examined the dynamics of tidal propagation inside a tropical lagoon. Sea surface elevation (inside) and current profiles (at the inlet) were examined over 60 days at the Chelem lagoon, which is a branched tropical lagoon located in the northern Yucatan Peninsula. Tides were predominantly diurnal with a wavelength at least 20 times longer than the total length of the basin. Spatial variations of sea surface elevation and the longitudinal transport were described in each branch by applying a linear analytical model and the results were compared to observations. Results showed that the coastal lagoon was highly frictional. The tidal signal was attenuated between 30% and 40% toward the lagoon heads, a result of the balance between pressure gradient and frictional forces. A causeway that chokes the western side of the lagoon allowed the propagation of the diurnal signal toward the west head of the basin but damped the semidiurnal signal. The causeway acted as a hydraulic low-pass filter, as in natural choked systems. The causeway's filter effect was included in the analytical model by optimizing the frictional parameters.

  14. Pathways of priority pesticides in sediments of coastal lagoons: The case study of Óbidos Lagoon, Portugal.

    PubMed

    Pinto, M I; Vale, C; Sontag, G; Noronha, J P

    2016-05-15

    This study reports the concentrations of the priority pesticides (PPs) in 14 surface sediments and 21 layers of a sediment core from Óbidos Lagoon, a shallow Portuguese coastal lagoon. Results show that the PPs are confined to the upper part of the lagoon that receives most of the inputs from surface runoff of the surrounding agricultural fields and from small tributaries. Past and recent applied PPs were registered in sediments, aluminum normalized concentrations varying between 0.05×10(-7) and 6.85×10(-7). The PP risk assessment based on sediment quality guidelines like the "Probable Effect Level" (PEL) shows no biological effects in either sediments or aquatic organisms of Óbidos Lagoon, except for dieldrin, lindane, DDT, heptachlor epoxide and its parent compound heptachlor.

  15. Comparative hydrodynamics of 10 Mediterranean lagoons by means of numerical modeling

    NASA Astrophysics Data System (ADS)

    Umgiesser, Georg; Ferrarin, Christian; Cucco, Andrea; De Pascalis, Francesca; Bellafiore, Debora; Ghezzo, Michol; Bajo, Marco

    2014-04-01

    A comparison study between 10 Mediterranean lagoons has been carried out by means of the 3-D numerical model SHYFEM. The investigated basins are the Venice and Marano-Grado lagoons in the Northern Adriatic Sea, the Lesina and Varano lagoons in the Southern Adriatic Sea, the Taranto basin in the Ionian Sea, the Cabras Lagoon in Sardinia, the Ganzirri and Faro lagoons in Sicily, the Mar Menor in Spain, and the Nador Lagoon in Morocco. This study has been focused on hydrodynamics in terms of exchange rates, transport time scale, and mixing. Water exchange depends mainly on the inlet shape and tidal range, but also on the wind regimes in the case of multi-inlet lagoons. Water renewal time, which is mostly determined by the exchange rate, is a powerful concept that allows lagoons to be characterized with a time scale. In the case of the studied lagoons, the renewal time ranged from few days in the Marano-Grado Lagoon up to 1 year in the case of the Mar Menor. The analysis of the renewal time frequency distribution allows identifying subbasins. The numerical study proved to be a useful tool for the intercomparison and classification of the lagoons. These environments range from a leaky type to a choked type of lagoons and give a representative picture of the lagoons situated around the Mediterranean basin. Mixing efficiency turns out to be a function of the morphological complexity, but also of the forcings acting on the system.

  16. Central Facilities Area Sewage Lagoon Evaluation

    SciTech Connect

    Mark R. Cole

    2013-12-01

    The Central Facilities Area (CFA), located in Butte County, Idaho, at the Idaho National Laboratory has an existing wastewater system to collect and treat sanitary wastewater and non-contact cooling water from the facility. The existing treatment facility consists of three cells: Cell #1 has a surface area of 1.7 acres, Cell #2 has a surface area of 10.3 acres, and Cell #3 has a surface area of 0.5 acres. If flows exceed the evaporative capacity of the cells, wastewater is discharged to a 73.5-acre land application site that uses a center-pivot irrigation sprinkler system. As flows at CFA have decreased in recent years, the amount of wastewater discharged to the land application site has decreased from 13.64 million gallons in 2004 to no discharge in 2012 and 2013. In addition to the decreasing need for land application, approximately 7.7 MG of supplemental water was added to the system in 2013 to maintain a water level and prevent the clay soil liners in the cells from drying out and “cracking.” The Idaho National Laboratory is concerned that the sewage lagoons and land application site may be oversized for current and future flows. A further concern is the sustainability of the large volumes of supplemental water that are added to the system according to current operational practices. Therefore, this study was initiated to evaluate the system capacity, operational practices, and potential improvement alternatives, as warranted.

  17. Ne-20/Ne-22 in the Martian Atmosphere: New Evidence from Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Park, J.; Nyquist, L. E.; Herzog, G. F.; Nagao, K.; Mikouchi, T.; Kusakabe, M.

    2017-01-01

    Analyses of Ne trapped in "pods" of impact melt in the Elephant Moraine 79001 (EET 79001) Martian meteorite led to suggest (Ne-20/Ne-22) approx.10 in the Martian atmosphere (MA). In contrast, obtained trapped (Ne-20/Ne-22)Tr approx.7 from an impact melt vein in Yamato 793605 (Y-793605) and concluded that the isotopic composition of Martian Ne remained poorly defined. A "pyroxene-rich" separate from Dhofar 378 (Dho 378) analyzed gave a comparatively high trapped Ne concentration and (Ne-20/Ne-22) = 7.3+/-0.2 in agreement with the Y-793605 value. We explore the hypothesis that Martian Ne was trapped in the Dho 378 meteorite in a manner similar to entrapment of terrestrial Ne in tektites strengthening the "Martian atmosphere" interpretation. We also report new data for Northwest Africa 7034 (NWA 7034) that are consistent with the Ne data for Dho 378.

  18. Phytoplankton assemblages in lateral lagoons of a large tropical reservoir.

    PubMed

    Ferrareze, M; Nogueira, M G

    2013-02-01

    This study aimed to analyse the composition and ecological attributes of the phytoplankton assemblages in four lateral lagoons and in the main channel of Rosana Reservoir (Paranapanema River, SE Brazil). Fieldwork was carried out in September and November/2004 and January, March, May and August/2005. A total of 283 taxa was identified. Zygnemaphyta was the most specious group, followed by Chlorophyta and Bacillariophyta. Higher richness, abundance and biomass were observed in the lagoons when compared with the river-reservoir sampling point, especially during the rainy period. Cryptophyceae and Bacillariophyceae dominated numerically. Cryptomonas brasiliensis Castro, Bicudo and Bicudo was the main species of the phytoplankton in terms of abundance and frequency of occurrence. The dynamics of the most important taxa are discussed and the results showed that the phytoplankton assemblages are mainly influenced by meteorological factors and nutrient availability (the main driving forces). Correlation analyses indicated that the assemblage abundance was limited by nutrient (nitrogen and phosphorus). The phytoplankton abundance influenced positively the zooplankton abundance, what indicates the prevalence of bottom-up control routes in the lateral lagoons system. The results validate the hypotheses that lateral lagoons have a prominent ecological role on the phytoplankton diversity, as already previously demonstrated for fish and zooplankton. Therefore, the incorporation of the lateral lagoons in environmental programmes should be a target strategy for the conservation of the regional aquatic biota, minimising the negative impact of the dam.

  19. Fine and coarse components in surface sediments from Bikini Lagoon

    SciTech Connect

    Noshkin, V. E., LLNL

    1997-01-01

    In 1979, 21 years after the moratorium on nuclear testing in the Marshall Islands, surface sediment samples (to depths of 2 and 4 cm) were collected from 87 locations in the lagoon of Bikini Atoll, one of the two sites in the Marshall Islands used by the United States to test nuclear devices from 1946 through 1958. The main purpose for the collections was to map the distribution of long-lived man-made radionuclides associated with the bottom material. In addition the samples were processed to estimate the fraction of fine and coarse components to show, by comparison, what modifications occurred in the composition since the sediments were first described in samples collected before testing in 1946. Nuclear testing produced more finely divided material that is now found in the surface sediment layer over large areas of the lagoon and especially in regions of the lagoon and reef adjacent to test sites. The 5 cratering events alone at Bikini Atoll redistributed sufficient material to account for the higher inventory of fine material found over the surface 4 cm of the sediment of the lagoon. Although the fraction of fine material in the bottom sediments was altered by the nuclear events, the combined processes of formation, transport and deposition were not sufficiently dynamic to greatly change the general geographical features of the major sedimentary components over most of the lagoon floor.

  20. Geochemical characterization of seaplane lagoon sediments, Alameda Naval Air Station

    SciTech Connect

    Bono, A; Carroll, S; Esser, B; Luther, G W; O'Day, P; Randall, S

    1999-08-16

    Our objective in the characterization of sediments from Seaplane Lagoon at the Alameda Naval Air Station (NAS) was to determine the geochemical interactions that control the partitioning of cadmium, chromium, cobalt, copper, lead, mercury, nickel, and zinc between the sediments and the porewaters. Our approach was to collect several cores at the east outfall location of the Seaplane Lagoon. We determined the porewater chemistry by (1) making in situ micro-electrode measurements, (2) extracting porewaters, and (3) modeling geochemical reactions. We determined the sediment chemistry by measuring (1) elemental abundance, (2) mineralogy, and (3) trace-element speciation. This information should help the US Navy determine the long-term hazard of the sediments if they are left in place and the short-term hazard if they are dredged. We did not fully examine the geochemistry of sediments from the West Beach Landfill Wetlands site, because these sediments were distinct from the Seaplane Lagoon sediments. Our initial motivation for studying the Landfill Wetlands site was to determine the trace-element geochemistry in Seaplane Lagoon sediments that had been dredged and then disposed in the Landfill Wetlands. Unfortunately, the location of these dredged sediments is unknown. The cores we sampled were not from the Seaplane Lagoon.

  1. Response Of A Tidal Environment To Changes In The Forcing: Insights From The Southern Venice Lagoon (Italy)

    NASA Astrophysics Data System (ADS)

    Roner, M.; D'Alpaos, A.; Ghinassi, M.; Fedi, M.; Bellucci, L. G.; Vigliotti, L.

    2014-12-01

    The Venice Lagoon represents an outstanding example of man-landscape co-existence, where salt marshes are currently exposed to possibly irreversible transformations due to the effects of climate changes and human activity. The increasing rate of relative sea level rise and the decreasing sediment supply are the dominant forcings controlling salt-marshes survival, as in other cases worldwide. Analysing signatures of landscape changes in the stratigraphic record is crucial to refine our knowledge of tidal landform dynamics and it is a first step to develop predictive morphodynamic models. The southern Venice lagoon is suited to analyze the response of tidal landscape to changes in environmental forcing. The upper part of the Holocene sedimentary succession accumulated as the effect of a "human-induced transgression", which caused a considerable salt-marshes contraction since the 16th century. In the southern Venice lagoon, re-directions of the Brenta River during 16th and the 19th century caused significant changes in terms of freshwater and sediment supply. To analyze the paleomorphodynamic response to these main changes, we collected 25 cores (1.0 to 1.5 m deep) along a NE-SW linear transect about 5 km long cutting through salt-marsh, tidal-flat and subtidal-platform deposits. Through sedimentological analyses we defined the spatial arrangement of swamp, salt-marsh, wave-worked and tidal-flat mud deposits along this transect. Magnetic susceptibility and organic/inorganic content were measured in the study succession, which was dated through 14C and 137Cs geochronological analyses. Our results suggest that salt-marsh sedimentation occurred above deltaic deposits since the 14th century. Salt-marsh aggradation stemmed out from both mud settling and organic accumulation, although magnetic susceptibility revealed some intervals during which the inorganic deposition dominates over organic accumulation. Salt-marsh aggradation occurred in parallel with the decrease in salt

  2. Nutrient-Chlorophyll Relationships in the Indian River Lagoon, Florida(SEERS)

    EPA Science Inventory

    The Indian River Lagoon is a highly diverse estuary located along Florida’s Atlantic coast. The system is made up of the main stem and two side-lagoons: the Banana River and Mosquito Lagoon. We segmented the main stem into three sections based on spatial trends in water quality ...

  3. A system for estimating bowen ratio And evaporation from waste lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A low cost system was deployed above a swine waste lagoon to obtain estimates of Bowen ratios and characterize lagoon temperatures. The system consisted of humidity and temperature sensors and anemometers deployed above the lagoon, water temperature sensors, and a meteorological station located by t...

  4. LANDSAT imagery of the Venetian Lagoon: A multitemporal analysis

    NASA Technical Reports Server (NTRS)

    Alberotanza, L.; Zandonella, A. (Principal Investigator)

    1980-01-01

    The use of LANDSAT multispectral scanner images from 1975 to 1979 to determine pollution dispersion in the central basin of the lagoon under varying tidal conditions is described. Images taken during the late spring and representing both short and long range tidal dynamics were processed for partial haze removal and removal of residual striping. Selected spectral bands were correlated to different types of turbid water. The multitemporal data was calibrated, classified considering sea truth data, and evaluated. The classification differentiated tide diffusion, algae belts, and industrial, agricultural, and urban turbidity distributions. Pollution concentration is derived during the short time interval between inflow and outflow and from the distance between the two lagoon inlets and the industrial zones. Increasing pollution of the lagoon is indicated.

  5. Eutrophication Process on Coastal Lagoons of North of Sinaloa, Mexico

    NASA Astrophysics Data System (ADS)

    Escobedo-Urias, D.; Martinez-Lopez, A.

    2007-05-01

    Coastal ecosystems in the Gulf of California support diverse and important fisheries and are reservoirs of great biological diversity. In northern Sinaloa, population growth and development, as well as increased use of these natural systems for recreation, has substantially increased the pressure placed upon marine resources. Discharge of untreated wastewaters generated by diverse human activities has been notably altered its health and integrity, principally along the lagoon's eastern shore In the late 60s, agriculture moved into a dominant role in coastal northern Sinaloa. The coastal plain encompasses more than 200,000 hectares under cultivation that now introduces large amounts of organic material, pesticides, heavy metals, and fertilizers into the lagoon systems of Topolobampo and San Ignacio-Navachiste-Macapule System at drainage discharge points and a minor grade in Colorado Lagoon. These lagoons are shallow and exhibit low water quality, lost of lagoon depth, presence of toxic substances (heavy metals) near the discharge points of wastewaters, and presence of harmful algal blooms. With the aim of evaluate the nutrients loadings (wastewaters, groundwaters) and their effects on the coastal lagoons of north of Sinaloa, the preliminary analysis of the physical, chemical and biologic variables data series are analyzed. From 1987-2007 eutrophication process is identified in Topolobampo Complex show increase tendency in annual average concentrations of DIN (Dissolved Inorganic Nitrogen= NO2+NO3) from 0.5 μ M in 1987 to 2.7 μ M in 2006. Trophic Index (TRIX) values, low nutrient ratios (N: P and N: Si) and the phytoplanktonic community structure support this result. Preliminary results of nutrients loadings show a mayor contribution of wastewaters into the coastal zone.

  6. State Waste Discharge Permit application, 100-N Sewage Lagoon

    SciTech Connect

    Not Available

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations (Ecology et al. 1994), the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173--216 (or 173--218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order No. DE 91NM-177, (Ecology and DOE-RL 1991). This document constitutes the State Waste Discharge Permit application for the 100-N Sewage Lagoon. Since the influent to the sewer lagoon is domestic waste water, the State Waste Discharge Permit application for Public Owned Treatment Works Discharges to Land was used. Although the 100-N Sewage Lagoon is not a Public Owned Treatment Works, the Public Owned Treatment Works application is more applicable than the application for industrial waste water. The 100-N Sewage Lagoon serves the 100-N Area and other Hanford Site areas by receiving domestic waste from two sources. A network of sanitary sewer piping and lift stations transfers domestic waste water from the 100-N Area buildings directly to the 100-N Sewage Lagoon. Waste is also received by trucks that transport domestic waste pumped from on site septic tanks and holding tanks. Three ponds comprise the 100-N Sewage Lagoon treatment system. These include a lined aeration pond and stabilization pond, as well as an unlined infiltration pond. Both piped-in and trucked-in domestic waste is discharged directly into the aeration pond.

  7. Population studies on the Amphipoda of Mazoma Lagoon (Greece)

    NASA Astrophysics Data System (ADS)

    Karakiri, Maria; Nicolaidou, Artemis

    1987-12-01

    The life cycles of four amphipod species— Gammarus insensibilis, Dexamine spinosa, Microdeutopus gryllotalpa and Corophium insidiosum—were studied in the brackish-water lagoon Mazoma of the Amvrakikos Gulf, Ionian Sea. G. insensibilis has an annual life cycle with limited recruitment over the year and maximum reproductive activity in the winter months. D. spinosa exhibits continuous recruitment in the lagoon with a maximum in summer. Both species produce a single brood per female per yer. Continuous recruitment was observed during the summer months for M. gryllotalpa and C. insidiosum, and multiple breeding per female per year. Sex ratios varied considerably over the year, with a persisting preponderance of the females.

  8. Spreading lagooned sewage sludge on farm land: A case history

    SciTech Connect

    Robson, C.M.; Sommers, L.E.

    1995-06-01

    This report describes the development of a project involving the application of approximately 265,000 cubic meters of lagooned sewage sludge from a metropolitan area on privately-owned farm land in an adjacent, rural county. The sludge application project was initiated to enable use of the land occupied by the lagoons for expansion of the sewage treatment plant. The procedures developed will be valuable to those proposing to practice land disposal of stabilized sludge as part of the Nation`s resource conservation program.

  9. Optical researches for cyanobacteria bloom monitoring in Curonian Lagoon

    NASA Astrophysics Data System (ADS)

    Shirshin, Evgeny A.; Budylin, Gleb B.; Yakimov, Boris P.; Voloshina, Olga V.; Karabashev, Genrik S.; Evdoshenko, Marina A.; Fadeev, Victor V.

    2016-04-01

    Cyanobacteria bloom is a great ecological problem of Curonian Lagoon and Baltic Sea. The development of novel methods for the on-line control of cyanobacteria concentration and, moreover, for prediction of bloom spreading is of interest for monitoring the state of ecosystem. Here, we report the results of the joint application of hyperspectral measurements and remote sensing of Curonian Lagoon in July 2015 aimed at the assessment of cyanobacteria communities. We show that hyperspectral data allow on-line detection and qualitative estimation of cyanobacteria concentration, while the remote sensing data indicate the possibility of cyanobacteria bloom detection using the spectral features of upwelling irradiation.

  10. Lagoon Seepage Testing Procedures for Central Facilities Area (CFA) Sewage Lagoons at Idaho National Laboratory Butte County, Idaho April 2014

    SciTech Connect

    Alan Giesbrecht

    2014-05-01

    The lagoon seepage testing procedures are documented herein as required by the Wastewater Rules (IDAPA 58.01.16.493). The Wastewater Rules and Wastewater Reuse Permit LA-000141-03 require that the procedure used for performing a seepage test be approved by IDEQ prior to conducting the seepage test. The procedures described herein are based on a seepage testing plan that was developed by J-U-B ENGINEERS, Inc. (J-U-B) and has been accepted by several IDEQ offices for lagoons in Idaho.

  11. Comparison of the triple-point temperatures of {sup 20}Ne, {sup 22}Ne and normal Ne

    SciTech Connect

    Nakano, T.; Tamura, O.; Nagao, K.

    2013-09-11

    At the National Metrology Institute of Japan (NMIJ), the triple points of {sup 20}Ne and {sup 22}Ne were realized using modular sealed cells, Ec3Ne20 and Ec8Ne22, made by the Istituto Nazionale di Ricerca Metrologica (INRiM) in Italy. The difference of the triple-point temperatures of {sup 20}Ne and {sup 22}Ne was estimated by using the sub-range of standard platinum resistance thermometers (SPRTs) calibrated by NMIJ on the International Temperature Scale of 1990 (ITS-90). The melting curves obtained with the Ec3Ne20 and Ec8Ne22 cells show narrow widths (0.1 mK) over a wide range of the inverse of the melted fraction (1/F) from 1/F=1 to 1/F=10. The liquidus point T{sub tp} estimated by the melting curves from F∼0.5 to F∼0.85 using the Ec8Ne22 is 0.146 29 (4) K higher than that using the Ec3Ne20 cell, which is in good agreement with that observed by INRiM using the same cells. After correction of the effect of impurities and other isotopes for Ec3Ne20 and Ec8Ne22 cells, the difference of T{sub tp} between pure {sup 20}Ne and pure {sup 22}Ne is estimated to be 0.146 61 (4) K, which is consistent with the recent results reported elsewhere. The sub-ranges of SPRTs computed by using the triple point of {sup 20}Ne or {sup 22}Ne realized by the Ec3Ne20 cell or the Ec8Ne22 cell in place of the triple point of Ne for the defining fixed point of the ITS-90 are in good agreement with those realized on the basis of the ITS-90 at NMIJ within 0.03 mK, which is much smaller than the non-uniqueness and the sub-range inconsistency of SPRTs.

  12. Estimating greenhouse gas emissions from a waste lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A cost-effective approach was used to investigate the relationship between emission of the greenhouse gases (GHG) CO2, CH4, and N2O and energy fluxes from a swine waste lagoon. Energy fluxes were calculated using the Penman method. The energy fluxes showed a diurnal pattern as expected of such flux...

  13. Fate of estradiol and testosterone in anaerobic lagoon digestors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory-scale lagoon digestors were constructed, and the fate of 14C-labelled 17ß-estradiol (E2) and testosterone (Test) were monitored for 42 d anaerobically under biological and sterile conditions. Hormone levels decreased in the liquid layer and increased in the sludge with time. At 42 d, 16-2...

  14. Aerated Lagoons. Instructor's Guide. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Andersen, Lorri

    This unit (which consists of a single lesson) describes the structural and operationally unique features of aerated lagoons. In addition, special troubleshooting and maintenance problems are discussed. The instructor's guide for the unit includes: (1) an overview of the lesson; (2) lesson plan; (3) lecture outline (keyed to a set of slides used…

  15. Facultative Lagoons. Instructor's Guide. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Andersen, Lorri

    This instructor's guide contains materials needed to teach a two-lesson unit on the structure and components of facultative lagoons, the biological theory of their operation, and factors affecting their operation. Control testing recommendations, maintenance guidelines, and troubleshooting hints are also provided. These materials include: (1) an…

  16. A Field Study Training Program on Wastewater Lagoon Systems.

    ERIC Educational Resources Information Center

    Water and Wastewater Technical School, Neosho, MO.

    This publication is a text and reference manual for operating personnel of both large and small wastewater lagoon systems with support from the Environmental Protection Agency (EPA). As a text, this inservice training manual is intended to be used in a correspondence course wherein the trainee or operator would read and study each chapter before…

  17. Antibiotic resistant bacterial profiles of anaerobic swine lagoon effluent.

    PubMed

    Brooks, J P; McLaughlin, M R

    2009-01-01

    Although land application of swine (Sus scrofa) manure lagoon effluent is a common and effective method of disposal, the presence of antibiotic-resistant bacteria, both pathogenic and commensal can complicate already understood issues associated with its safe disposal. The aim of this study was to assess antibiotic resistance in swine lagoon bacteria from sow, nursery, and finisher farms in the southeastern United States. Effluents from 37 lagoons were assayed for the presence of Escherichia coli, Campylobacter, Listeria, and Salmonella. Antibiotic resistance profiles were determined by the Kirby-Bauer swab method for 12 antibiotics comprising eight classes. Statistical analyses indicated that farm type influenced the amount and type of resistance, with nurseries and sow farms ranking as most influential, perhaps due to use of more antibiotic treatments. Finisher farms tended to have the least amount of antibiotic class resistance, signaling an overall healthier market pig, and less therapeutic or prophylactic antibiotic use. Many bacterial isolates were resistant to penicillin, cephalosporin, and tetracycline class antibiotics, while nearly all were susceptible to quinolone antibiotics. It appeared that swine farm type had a significant association with the amount of resistance associated with bacterial genera sampled from the lagoons; nurseries contributed the largest amount of bacterial resistance.

  18. Augmenting Lagoon Process Using Reactivated Freeze-dried Biogranules.

    PubMed

    Pishgar, Roya; Hamza, Rania Ahmed; Tay, Joo Hwa

    2017-02-24

    This study investigated the feasibility of using freeze-dried biogranules in lagoon basins. The effect of different operational conditions on treatment performance and detention time of granule-based lagoons was examined in a series of laboratory-scale batch studies. Optimal granule dosage was 0.1 g/L under anaerobic condition, resulting in 80-94% removal of 1000 mg/L chemical oxygen demand (COD) in 7-10 days. Under aerobic condition, granule dosage of 0.2 g/L achieved the best result for identical COD concentration. However, adequate amount of nutrients (optimal COD/N/P ratio of 100/13/0.8) should be supplied to encourage the growth of aerobic species. At optimal COD/N/P ratio, aerobic treatment interval significantly reduced to 2-3 days with corresponding COD removal efficiency of 88-92%. Inhibition of high concentrations of COD (5000 mg/L) and ammonia (480 mg/L NH4-N) was observed on microbial activity and treatment capacity of the biogranules. Mixing was a crucial measure to overcome mass transfer limitation. Onetime inoculation of lagoon with fresh granules was the best approach to achieve a satisfactory treatment efficiency. This study suggested that utilization of the biogranules is a feasible and sustainable technique for augmenting lagoon plants in terms of improved effluent quality and reduced retention time. Graphical Abstract ᅟ.

  19. Holocene carbonate sedimentation in Aitutaki Lagoon, Cook Islands, South Pacific

    SciTech Connect

    Richmond, B.M.; Hein, J.R.

    1987-05-01

    Aitutaki, an almost-atoll in the Southern Cook Islands, is characterized by a shallow enclosed lagoon. Sediment distribution within the lagoon can be broadly placed into three sedimentary-bathymetric provinces. (1) A low-relief reef rim (< 2 m deep), including sand flats and washover fans, is comprised mostly of clean sand and gravel. (2) The majority of the lagoon floor, which lies between 3 and 6 m water depth, is dominated by sand and silt; coral-algal patch reefs are common with densities greater than 500 reefs/km/sup 2/. Sediment commonly is coarser grained near the patch reefs. (3) Enclosed and elongate-sinuous topographic lows (basins) up to 10 m deep are marked by coral-algal reef growth along their margins. These features are typically narrow, less than 100 m wide, and are U-shaped in cross section and infilled by carbonate and terrigenous muds. High-resolution continuous seismic profiling and limited drilling indicate that differences in thickness of Holocene sediment result from primary irregularities in the pre-Holocene basement surface. Aitutaki was formed by late Miocene volcanism, with a post-edifice building mid-Pleistocene (0.77 Ma) volcanic episode. Two islets within the lagoon are also of volcanic origin, and sinuous coral ridges which extend for several kilometers probably developed on Quaternary lava flows. The coral ridges and meandering enclosed basins appear to be unique to Aitutaki in the Cook Islands.

  20. A new sampler for stratified lagoon chemical and microbiological assessments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A water column sampler was needed to study stratification of nutrients and bacteria in a swine manure lagoon. Conventional samplers yielded shallow samples near the bank or required a boat. These limitations prompted development of a new sampler to collect at multiple depths with minimal disturbanc...

  1. Distribution and stability of eelgrass beds at Izembek Lagoon, Alaska

    USGS Publications Warehouse

    Ward, David H.; Markon, Carl J.; Douglas, David C.

    1997-01-01

    Spatial change in eelgrass meadows, Zostera marina L., was assessed between 1978 and 1987 and between 1987 and 1995 at Izembek Lagoon, Alaska. Change in total extent was evaluated through a map to map comparison of data interpreted from a 1978 Landsat multi-spectral scanner image and 1987 black and white aerial photographs. A ground survey in 1995 was used to assess spatial change from 1987. Eelgrass beds were the predominant vegetation type in the lagoon, comprising 44-47% (15000-16000 ha) of the total area in 1978 and 1987. Izembek Lagoon contains the largest bed of seagrass along the Pacific Coast of North America and largest known single stand of eelgrass in the world. There was a high degree of overlap in the spatial distribution of eelgrass among years of change detection. The overall net change was a 6% gain between, 1978 and 1987 and a <1% gain between 1987 and 1995. The lack of significant change in eelgrass cover suggests that eelgrass meadows in Izembek Lagoon have been stable during the 17-year period of our study.

  2. Methane Dynamics in Sediments from Mangrove-dominated Costal Lagoons

    NASA Astrophysics Data System (ADS)

    Chuang, P. C.; Paytan, A.; Young, M. B.

    2014-12-01

    Porewater methane and sulfate concentrations from cored sediments have been measured in two coastal mangrove ecosystems (Celestún and Chelem Lagoons) on the Yucatán Peninsula, Mexico. Methane exists in shallow sediments while sulfate is not depleted and stable carbon isotopes of methane (-87.27‰ ~ -62.08‰) imply high methane fluxes/production rates below and within the cored sediment depths. The preliminary results from a transport-reaction model show that methane emitted to the water column from these sediments could be 17.8 mg m-2 d-1 in Celestún Lagoon and much higher (565 mg m-2 d-1) in Chelem Lagoon. Since the water depths are shallow (mostly less than 100 cm), the high fluxes of methane could contribute to the atmosphere. The objectives of this study will aim to understand the biogeochemical cycles for methane and sulfate in sediments. A numerical transport-reaction model will be applied to the sedimentary geochemical data (methane, sulfate, chloride, particulate organic carbon (POC) and stable carbon isotopes of headspace methane) from the two lagoons to estimate sulfate reduction, methane oxidation and production rates and advective methane fluxes. The modeled results will be used to discuss the role of methane from mangrove areas and their potential contribution to the global methane cycle.

  3. Benthic Primary Production Budget of a Caribbean Reef Lagoon (Puerto Morelos, Mexico)

    PubMed Central

    Naumann, Malik S.; Jantzen, Carin; Haas, Andreas F.; Iglesias-Prieto, Roberto; Wild, Christian

    2013-01-01

    High photosynthetic benthic primary production (P) represents a key ecosystem service provided by tropical coral reef systems. However, benthic P budgets of specific ecosystem compartments such as macrophyte-dominated reef lagoons are still scarce. To address this, we quantified individual and lagoon-wide net (Pn) and gross (Pg) primary production by all dominant functional groups of benthic primary producers in a typical macrophyte-dominated Caribbean reef lagoon near Puerto Morelos (Mexico) via measurement of O2 fluxes in incubation experiments. The photosynthetically active 3D lagoon surface area was quantified using conversion factors to allow extrapolation to lagoon-wide P budgets. Findings revealed that lagoon 2D benthic cover was primarily composed of sand-associated microphytobenthos (40%), seagrasses (29%) and macroalgae (27%), while seagrasses dominated the lagoon 3D surface area (84%). Individual Pg was highest for macroalgae and scleractinian corals (87 and 86 mmol O2 m−2 specimen area d−1, respectively), however seagrasses contributed highest (59%) to the lagoon-wide Pg. Macroalgae exhibited highest individual Pn rates, but seagrasses generated the largest fraction (51%) of lagoon-wide Pn. Individual R was highest for scleractinian corals and macroalgae, whereas seagrasses again provided the major lagoon-wide share (68%). These findings characterise the investigated lagoon as a net autotrophic coral reef ecosystem compartment revealing similar P compared to other macrophyte-dominated coastal environments such as seagrass meadows and macroalgae beds. Further, high lagoon-wide P (Pg: 488 and Pn: 181 mmol O2 m−2 lagoon area d−1) and overall Pg:R (1.6) indicate substantial benthic excess production within the Puerto Morelos reef lagoon and suggest the export of newly synthesised organic matter to surrounding ecosystems. PMID:24367570

  4. Aspects of fish conservation in the upper Patos Lagoon basin.

    PubMed

    Fontoura, N F; Vieira, J P; Becker, F G; Rodrigues, L R; Malabarba, L R; Schulz, U H; Möller, O O; Garcia, A M; Vilella, F S

    2016-07-01

    The Patos Lagoon basin is a large (201 626 km(2) ) and complex drainage system in southern Brazil. The lagoon is 250 km long and 60 km wide, covering an area of 10 360 km(2) . The exchange of water with the Atlantic Ocean occurs through a 0·8 km wide and 15 m deep inlet, fixed by 4 km long jetties, at the southernmost part of the Patos Lagoon. The estuarine area is restricted to its southern portion (10%), although the upper limit of saline waters migrates seasonally and year to year, influenced by the wind regime and river discharge. The known number of recorded limnetic fish species is 200, but this number is expected to increase. A higher endemism is observed in fish species occurring in upper tributaries. The basin suffers from the direct impact of almost 7 million inhabitants, concentrated in small to large cities, most with untreated domestic effluents. There are at least 16 non-native species recorded in natural habitats of the Patos Lagoon basin, about half of these being from other South American river basins. Concerning the fishery, although sport and commercial fisheries are widespread throughout the Patos Lagoon basin, the lagoon itself and the estuarine area are the main fishing areas. Landing statistics are not available on a regular basis or for the whole basin. The fishery in the northern Patos Lagoon captures 31 different species, nine of which are responsible for most of the commercial catches, but only three species are actually sustaining the artisanal fishery: the viola Loricariichthys anus: 455 kg per 10 000 m(2) gillnet per day, the mullet Mugil liza: 123 kg per 10 000 m(2) gillnet per day and the marine catfish Genidens barbus: 50 kg per 10 000 m(2) gillnet per day. A decline of the fish stocks can be attributed to inadequate fishery surveillance, which leads to overfishing and mortality of juveniles, or to decreasing water quality because of urban and industrial activities and power production. Global climatic changes also represent a

  5. Nitrification and denitrification gene abundances in swine wastewater anaerobic lagoons.

    PubMed

    Ducey, Thomas F; Shriner, Anthony D; Hunt, Patrick G

    2011-01-01

    Although anaerobic lagoons are used globally for livestock waste treatment, their detailed microbial cycling ofN is only beginning to become understood. Within this cycling, nitrification can be performed by organisms that produce the enzyme ammonia monooxygenase. For denitrification, the reduction of nitrite to nitric oxide can be catalyzed by two forms of nitrite reductases, and N,O can be reduced by nitrous oxide reductase encoded by the gene nosZ The objectives of this investigation were to (i) quantify the abundance of the amoA, nirK, nirS, and nosZ genes; (ii) evaluate the influence of environmental conditions on their abundances; and (iii) evaluate their abundance relative to denitrification enzyme activity (DEA). Samples were analyzed via real-time quantitative polymerase chain reaction and collected from eight typical, commercial anaerobic, swine wastewater lagoons located in the Carolinas. The four genes assayed in this study were present in all eight lagoons. Their abundances relative to total bacterial populations were 0.04% (amoA), 1.33% (nirS), 5.29% (nirK), and 0.27% (nosZ). When compared with lagoon chemical characteristics, amoA and nirK correlated with several measured variables. Neither nirS nor nosZ correlated with any measured environmental variables. Although no gene measured in this study correlated with actual or potential DEA, nosZ copy numbers did correlate with the disparity between actual and potential DEA. Phylogenetic analysis ofnosZdid not reveal any correlations to DEA rates. As with other investigations, analyses of these genes provide useful insight while revealing the underlying greater complexity of N cycling within swine waste lagoons.

  6. Water sources, mixing and evaporation in the Akyatan lagoon, Turkey

    NASA Astrophysics Data System (ADS)

    Lécuyer, C.; Bodergat, A.-M.; Martineau, F.; Fourel, F.; Gürbüz, K.; Nazik, A.

    2012-12-01

    Akyatan lagoon, located southeast of Turkey along the Mediterranean coast, is a choked and hypersaline lagoon, and hosts a large and specific biodiversity including endangered sea turtles and migrating birds. Physicochemical properties of this lagoon were investigated by measuring temperature, salinity, and hydrogen and oxygen isotope ratios of its waters at a seasonal scale during years 2006 and 2007. Winter and spring seasons were dominated by mixing processes between freshwaters and Mediterranean seawater. The majority of spring season waters are formed by evapoconcentration of brackish water at moderate temperatures of 22 ± 2 °C. During summer, hypersaline waters result from evaporation of seawater and brackish waters formed during spring. Evaporation over the Akyatan lagoon reaches up to 76 wt% based on salinity measurements and operated with a dry (relative humidity of 0.15-0.20) and hot (44 ± 6 °C) air. These residual waters were characterized by the maximal seasonal isotopic enrichment in both deuterium and 18O relative to VSMOW. During autumn, most lagoonal waters became hypersaline and were formed by evaporation of waters that had isotopic compositions and salinities close to that of seawater. These autumnal hypersaline waters result from an air humidity close to 0.45 and an atmospheric temperature of evaporation of 35 ± 5 °C, which are responsible for up to 71 wt% of evaporation, with restricted isotopic enrichments relative to VSMOW. During the warm seasons, the combination of air humidity, wind velocity and temperature were responsible for a large kinetic component in the total isotopic fractionation between water liquid and water vapour.

  7. Isotopic Fractionation of 20Ne, 21Ne, and 22Ne in a Simulated Thermal Gradient

    NASA Astrophysics Data System (ADS)

    Jester, B.; Dominguez, G.

    2014-12-01

    Computer simulations allow for the analysis of the thermodynamic properties of systems which are difficult or impossible to do experimentally. Isotopic fractionation in thermal gradients is an example of a system which is not fully understood but could provide background for understanding variations in fractionations like those observed for noble gases in terrestrial and extraterrestrial material. Using a recently developed molecular dynamics simulation focused on the accuracy of the simulated physics, the isotopic fractionation of Neon in a thermal gradient was analyzed in order to provide a correlation between the fractionation and the experimental system's properties. Various ratios of isotopes 20Ne, 21Ne, and 22Ne were simulated in a thermal gradient ranging from 218 K to 233 K for a variety of time scales. Data was collected for various configurations including box sizes on the order of 1 nm to 100 μm. The simulated thermal conductivity was determined and compared with known values. The analysis indicates that the dimensions of the box heavily influence the magnitude of the isotopic fractionation in the thermal gradient.

  8. Crustacean zooplankton in aerated wastewater treatment lagoons as a potential feedstock for biofuel.

    PubMed

    Kring, Stefanie A; Xia, Xiaoyan; Powers, Susan E; Twiss, Michael R

    2013-01-01

    Zooplankton biomass productivity was estimated for two 64,000 m3 (1.7 ha) facultative aerated wastewater treatment lagoons to evaluate potential biodiesel production from zooplankton biomass. Lagoons were monitored bi-weekly during summer 2010. Lipid accumulated by crustacean zooplankton was considered the most efficient means by which to collect lipid produced by phytoplankton owing to the greater ease in the collection of these organisms (>0.153mm) compared with unicellular algae (size <0.06 mm). In terms of biomass, the cladoceran Daphnia and the copepod Cyclops were the dominant zooplankton in these hypereutrophic lagoons, while unicellular chlorophytes dominated the phytoplankton community. Secondary productivity of these lagoons (250 g of dry weight m(-2) yr(-1)) is comparable to the secondary productivity of other sewage lagoons. The potential biodiesel production for one lagoon was estimated to be 0.04 +/- 0.02 L m(-2) yr(-1), which results in a total of 1120 +/- 560 L from two lagoons. This study showed that there are organisms present in wastewater lagoons, besides algae, that can serve as a biofuel feedstock. Additionally, this research expands the current knowledge of facultative aerated wastewater lagoon ecology and waste stream-derived biofuel. Future research should include complete life cycle and economic analyses to determine if harvesting zooplankton from wastewater lagoons is a sustainable endeavour.

  9. An integrated Pan-European perspective on coastal Lagoons management through a mosaic-DPSIR approach.

    PubMed

    Dolbeth, Marina; Stålnacke, Per; Alves, Fátima L; Sousa, Lisa P; Gooch, Geoffrey D; Khokhlov, Valeriy; Tuchkovenko, Yurii; Lloret, Javier; Bielecka, Małgorzata; Różyński, Grzegorz; Soares, João A; Baggett, Susan; Margonski, Piotr; Chubarenko, Boris V; Lillebø, Ana I

    2016-01-18

    A decision support framework for the management of lagoon ecosystems was tested using four European Lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Tyligulskyi Liman (Ukraine) and Vistula Lagoon (Poland/Russia). Our aim was to formulate integrated management recommendations for European lagoons. To achieve this we followed a DPSIR (Drivers-Pressures-State Change-Impacts-Responses) approach, with focus on integrating aspects of human wellbeing, welfare and ecosystem sustainability. The most important drivers in each lagoon were identified, based on information gathered from the lagoons' stakeholders, complemented by scientific knowledge on each lagoon as seen from a land-sea perspective. The DPSIR cycles for each driver were combined into a mosaic-DPSIR conceptual model to examine the interdependency between the multiple and interacting uses of the lagoon. This framework emphasizes the common links, but also the specificities of responses to drivers and the ecosystem services provided. The information collected was used to formulate recommendations for the sustainable management of lagoons within a Pan-European context. Several common management recommendations were proposed, but specificities were also identified. The study synthesizes the present conditions for the management of lagoons, thus analysing and examining the activities that might be developed in different scenarios, scenarios which facilitate ecosystem protection without compromising future generations.

  10. Biogeochemical responses of shallow coastal lagoons to Climate Change

    NASA Astrophysics Data System (ADS)

    Brito, A.; Newton, A.; Tett, P.; Fernandes, T.

    2009-04-01

    The importance of climate change and global warming in the near future is becoming consensual within the scientific community (e.g. Kerr et al., 2008; Lloret et al., 2008). The surface temperature and sea level have increased during the last few years in the northern hemisphere (IPCC, 2007). Predictions for future changes include an increase of surface temperature and sea level for Europe. Moreover, the global warming phenomenon will also change the hydrological cycle and increase precipitation in northern and central Europe (IPCC, 2007). Sea level rise already threatens to overwhelm some lagoons, such as Venice and Moroccan lagoons (Snoussi et al., 2008). Shallow coastal lagoons are some of the most vulnerable systems that will be impacted by these changes (Eisenreich, 2005). Environmental impacts on coastal lagoons include an increase of water turbidity and therefore light attenuation. If these effects are strong enough, the lighted bottoms of shallow lagoons may loose a significant part of the benthic algal community. These communities are highly productive and are essential to control nutrient dynamics of the system by uptaking large amounts of nutrients both from the water column and from the sediments. A decrease in benthic algal communities and photosynthetic oxygen production will also contribute to increasing the vulnerability of the lagoons to hypoxia and anoxia. The flux of nutrients such as phosphate from the sediments may increase dramatically, further disrupting the nutrient balance and condition and promoting cyanobacterial blooms. Microbial activity is temperature dependent, therefore, the increase of temperature will increase the concentrations of ammonium within sediments. The release of phosphate and silicate will also increase with temperature. Coastal lagoons are valuable ecosystems and may be severely impacted, both ecologically and economically, by global change. Shallow coastal lagoons should be considered as sentinel systems and should be

  11. Toxicity of contaminants in lagoons and pannes of the Indiana Dunes National Lakeshore

    SciTech Connect

    Gillespie, R.; Speelman, J.; Stewart, P.M.

    1995-12-31

    Contaminants in water and sediments of lagoons and pannes were 2--90 times greater at sites adjacent to slag and coal piles than those at reference sites. One site (Lagoon-US5) had sediments with very high concentrations of toxic organics (e.g. naphthalene, phenanthrene, dibenzofuran). Although analyses indicated a gradient of contaminant concentration with distance from their sources, toxicity assays were somewhat equivocal. With the exception of less reproduction in Ceriodaphnia at one lagoon site (US3 = 0.55 of reference), survival of fathead minnows and reproduction in Ceriodaphnia in lagoon and panne waters varied independently of the contaminant concentration. In fact, there was better Ceriodaphnia reproduction in water from two contaminated sites (Lagoon-US5, Panne-WP1) than in water from reference sites. Fathead minnow survival, Ceriodaphnia survival, Ceriodaphnia reproduction, amphipod survival, and amphipod growth varied among sites in toxicity assays with sediments, 100% mortality of fatheads at Lagoon-US5, 100% mortality of Ceriodaphnia at Lagoon-US3, and less survival of fathead minnows at Lagoon-US3 indicate possible toxicity from contaminants in sediments at these sites. Of all organisms and end-points tested, Ceriodaphnia survival seemed to be most closely associated with concentrations of contaminants in lagoon water and sediments. Amphipod survival also varied with contaminants in sediments, however, survival in sediments of contaminated sites ranged only from 0.90--0.93 of reference sites. Although the results are not consistent among organisms, toxicity assays indicate that sediments from the lagoon site with the highest contaminants (Lagoon-US5) and possibly those from another contaminated lagoon site (Lagoon-US3) could be toxic to aquatic organisms. Water and sediments from contaminated panne sites do not appear to be toxic to aquatic test organisms.

  12. Photosynthetic pigments of Zoster a noltii and Ruppia cirrhosa in some Albanian lagoons

    NASA Astrophysics Data System (ADS)

    Ylli, Arjana; Babani, Fatbardha; Stamo, Iliriana

    2010-01-01

    In the coastal lagoons of Adriatic Sea Zostera noltii and Ruppia cirrhosa are plants with seeds and flowers, that colonizes the sandy bottom of lagoons. They are capable to produce oxygen with very weak light. Characterization of photosynthetic pigments of eelgrass Zostera noltii and Ruppia cirrhosa, were performed during the period 2002-2008 in some Adriatic lagoons: Kune-Vaini, Patog, Karavasta and Narta. Dynamics of chlorophylls and carotenoids during the vegetation period of these plants were characterized. As a result, the chlorophyll content of Zoostera noltii taken from the Kune- Vain lagoon is higher than at plants collected from the other lagoons. The photosynthetic pigment content of the Zostera noltii plants is higher than of Ruppia cirrhosa. The differences on the distribution of these species in the analyzed lagoons are represented in this presentation.

  13. Interannual and cyclone-driven variability in phytoplankton communities of a tropical coastal lagoon.

    PubMed

    Srichandan, Suchismita; Kim, Ji Yoon; Kumar, Abhishek; Mishra, Deepak R; Bhadury, Punyasloke; Muduli, Pradipta R; Pattnaik, Ajit K; Rastogi, Gurdeep

    2015-12-15

    One of the main challenges in phytoplankton ecology is to understand their variability at different spatiotemporal scales. We investigated the interannual and cyclone-derived variability in phytoplankton communities of Chilika, the largest tropical coastal lagoon in Asia and the underlying mechanisms in relation to environmental forcing. Between July 2012 and June 2013, Cyanophyta were most prolific in freshwater northern region of the lagoon. A category-5 very severe cyclonic storm (VSCS) Phailin struck the lagoon on 12th October 2013 and introduced additional variability into the hydrology and phytoplankton communities. Freshwater Cyanophyta further expanded their territory and occupied the northern as well as central region of the lagoon. Satellite remote sensing imagery revealed that the phytoplankton biomass did not change much due to high turbidity prevailing in the lagoon after Phailin. Modeling analysis of species-salinity relationship identified specific responses of phytoplankton taxa to the different salinity regime of lagoon.

  14. Priority pesticides in sediments of European coastal lagoons: A review.

    PubMed

    Pinto, M I; Burrows, Hugh D; Sontag, G; Vale, C; Noronha, J P

    2016-11-15

    This review summarizes the legislation applied to pesticides and highlights the physicochemical properties of the past and recently listed PPs under Water Framework Directive (WFD). It reports important information regarding the analysis, occurrence and long-term screening of PPs in sediments of European coastal lagoons. Among the entire list of PPs, those analyzed have been the organochloride insecticides, such as lindane, hexachlorobenzene and DDT. Although flood events pointed to the possible redistribution of pesticides, which may increase under climate change conditions, few studies are available concerning PPs screening in sediments of European coastal lagoons. Data is scarce not only in terms of the number of listed PPs that have been analyzed but also in terms of their long-term screening. This lack of data on PP concentrations is probably a consequence of the fact that less importance is given to the sediments contamination/quality.

  15. An integrated physical and biological model for anaerobic lagoons.

    PubMed

    Wu, Binxin; Chen, Zhenbin

    2011-04-01

    A computational fluid dynamics (CFD) model that integrates physical and biological processes for anaerobic lagoons is presented. In the model development, turbulence is represented using a transition k-ω model, heat conduction and solar radiation are included in the thermal model, biological oxygen demand (BOD) reduction is characterized by first-order kinetics, and methane yield rate is expressed as a linear function of temperature. A test of the model applicability is conducted in a covered lagoon digester operated under tropical climate conditions. The commercial CFD software, ANSYS-Fluent, is employed to solve the integrated model. The simulation procedures include solving fluid flow and heat transfer, predicting local resident time based on the converged flow fields, and calculating the BOD reduction and methane production. The simulated results show that monthly methane production varies insignificantly, but the time to achieve a 99% BOD reduction in January is much longer than that in July.

  16. Flooding and Environmental Challenges for Venice and its Lagoon

    NASA Astrophysics Data System (ADS)

    Fletcher, C. A.; Spencer, T.

    2005-07-01

    Time may be running out for Venice. The frequency of flooding is increasing and Venice is no better protected today than it was in November 1966, when a violent storm surge left the city under 2 metres of floodwater. The environmental future is bleak, with continuing land subsidence, acceleration in the rate of sea level rise and possible changes in storminess in prospect. Surrounding the city is a lagoon ecosystem showing signs of severe environmental degradation. This timely scientific and technical volume synthesises the great volume and diversity of recent interdisciplinary research on Venice and its lagoon. The lessons reported here are relevant not only to Venice but also to all those that live and work under the threat of coastal flooding, including the inhabitants of other great cultural centres, like London and St. Petersburg.

  17. Validation of Numerical Shallow Water Models for Tidal Lagoons

    SciTech Connect

    Eliason, D.; Bourgeois, A.

    1999-11-01

    An analytical solution is presented for the case of a stratified, tidally forced lagoon. This solution, especially its energetics, is useful for the validation of numerical shallow water models under stratified, tidally forced conditions. The utility of the analytical solution for validation is demonstrated for a simple finite difference numerical model. A comparison is presented of the energetics of the numerical and analytical solutions in terms of the convergence of model results to the analytical solution with increasing spatial and temporal resolution.

  18. Taphonomy of coral reefs from Southern Lagoon of Belize

    SciTech Connect

    Westphall, M.J.; Ginsburg, R.N.

    1985-02-01

    The Southern Lagoon of the Belize barrier complex, an area of some 600 km/sup 2/, contains a tremendous number of lagoon reefs, which range in size from patches several meters across to rhomboidal-shaped structures several kilometers in their long dimension. These lagoon reefs are remarkable because they have Holocene sediment accumulations in excess of 13 m consisting almost entirely of coral debris and lime mud and sand, and rise up to 30 m above the surrounding lagoon floor with steeply sloping sides (50-80/sup 0/), yet are totally uncemented. The reef-building biota and their corresponding deposits were studied at a representative reef, the rhomboidal complex of Channel Cay. As with many of the reefs in this area, the steeply sloping flanks of Channel Cay are covered mainly by the branched staghorn coral Acropora cervicornis and ribbonlike and platy growth of Agaricia spp. The living corals are not cemented to the substrate, but are merely intergrown. Fragmented pieces of corals accumulate with an open framework below the living community; this open framework is subsequently infilled by lime muds and sands produced mainly from bioerosion. Results from probing and coring suggest that the bafflestone fabric of coral debris and sediment extends at least 13 m into the subsurface. Radiocarbon-age estimates indicate these impressive piles of coral rubble and sediment have accumulated in the past 9000 yr (giving a minimum accumulation rate of 1.4 m/1000 yr) and illustrate the potential for significant carbonate buildups without the need for early lithification.

  19. Comparative study of wastewater lagoon with and without water hyacinth

    SciTech Connect

    McDonald, R.C.; Wolverton, B.C.

    1980-01-01

    A facultative sewage lagoon completely covered with water hyacinths had significant improvement in effluent quality. BOD 5 and total suspended solids (TSS) were 23 and b mg/L respectively. Without water hyacinths, the effluent BOD5 and TSS were 52 and 77 mg/L, respectively. The effluent total organic C concentration was reduced from 72 to 40 mg/L with water hyacinth coverage.

  20. Statistical characterization of spatiotemporal sediment dynamics in the Venice lagoon

    NASA Astrophysics Data System (ADS)

    Carniello, Luca; D'Alpaos, Andrea; Botter, Gianluca; Rinaldo, Andrea

    2016-05-01

    Characterizing the dynamics of suspended sediment is crucial when investigating the long-term evolution of tidal landscapes. Here we apply a widely tested mathematical model which describes the dynamics of cohesive and noncohesive sediments, driven by the combined effect of tidal currents and wind waves, using 1 year long time series of observed water levels and wind data from the Venice lagoon. The spatiotemporal evolution of the computed suspended sediment concentration (SSC) is analyzed on the basis of the "peak over threshold" theory. Our analysis suggests that events characterized by high SSC can be modeled as a marked Poisson process over most of the lagoon. The interarrival time between two consecutive over threshold events, the intensity of peak excesses, and the duration are found to be exponentially distributed random variables over most of tidal flats. Our study suggests that intensity and duration of over threshold events are temporally correlated, while almost no correlation exists between interarrival times and both durations and intensities. The benthic vegetation colonizing the central southern part of the Venice lagoon is found to exert a crucial role on sediment dynamics: vegetation locally decreases the frequency of significant resuspension events by affecting spatiotemporal patterns of SSCs also in adjacent areas. Spatial patterns of the mean interarrival of over threshold SSC events are found to be less heterogeneous than the corresponding patterns of mean interarrivals of over threshold bottom shear stress events because of the role of advection/dispersion processes in mixing suspended sediments within the lagoon. Implications for long-term morphodynamic modeling of tidal environments are discussed.

  1. Industrial waste treatment: Lagoons (ponds). (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-01-01

    The bibliography contains citations concerning the treatment and storage of wastewaters in lagoons. Lagoon design, operation, associated equipment, and pretreatment processes are discussed. Included in the references are treatment of wastewaters from breweries, tanneries, paper mills, agricultural operations, and other industrial operations. Descriptions and evaluations of specific facilities are provided. Municipal water and sewage treatment lagoons are referenced in a related bibliography. (Contains a minimum of 118 citations and includes a subject term index and title list.)

  2. Municipal sewage treatment: Lagoons (ponds). (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-11-01

    The bibliography contains citations concerning the treatment and storage of municipal wastewater and sewage in lagoons. Lagoon design, operation, and associated equipment for pretreatment, treatment, and storage techniques are discussed. Many citations describe the water treatment facilities of specific cities, and provide evaluations of the operations at those sites. Industrial and other non-municipal wastewater treatment lagoons are referenced in a related bibliography. (Contains 250 citations and includes a subject term index and title list.)

  3. Municipal sewage treatment: Lagoons (ponds). (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-07-01

    The bibliography contains citations concerning the treatment and storage of municipal wastewater and sewage in lagoons. Lagoon design, operation, and associated equipment for pretreatment, treatment, and storage techniques are discussed. Many citations describe the water treatment facilities of specific cities, and provide evaluations of the operations at those sites. Industrial and other non-municipal wastewater treatment lagoons are referenced in a related bibliography. (Contains 250 citations and includes a subject term index and title list.)

  4. Geoelectrical signals of geologic and hydrologic processes in a fringing reef lagoon setting

    NASA Astrophysics Data System (ADS)

    Befus, Kevin M.; Cardenas, M. Bayani; Tait, Douglas R.; Erler, Dirk V.

    2014-09-01

    Coastal groundwater may discharge into nearshore and offshore waters forced by terrestrial fluxes, controlled by local geology, and modulated by the hydrodynamics of littoral water. We investigated the electrical signature of these features with a dense, multiscale network of electrical resistivity tomography (ERT) surveys in the Muri Lagoon of Rarotonga, Cook Islands. The ERT surveys spanned from onshore to 400 m into the lagoon and used standard electrodes on land and across the foreshore, submerged electrodes in the shallow subtidal zone, and floating electrodes towed throughout the reef lagoon by a boat. ERT surveys on land mapped a typical freshwater lens underlain by a saltwater wedge, but with possible deviations from the classical model due to an adjacent tidal creek. Further inland, ERT surveys imaged a layer of lava flow deposits that is potentially a confining hydrogeologic unit; this unit was used to constrain the expected electrical resistivity of these deposits below the lagoon. ERT surveys across the intertidal zone and into the lagoon indicated fresh groundwater and porewater salinity patterns consistent with previous small-scale studies including the seaward extension of fresh groundwater pathways to the lagoon. Electrical resistivity (ER) variations in the lagoon subsurface highlighted heterogeneities in the lagoon structure that may focus submarine groundwater discharge (SGD) through previously unknown buried lava flow deposits in the lagoon. A transition to higher ER values near the reef crest is consistent with the ER signature of porosity reduction due to ongoing differential cementation of reef deposits across the lagoon. The imaged coastal hydrostratigraphic heterogeneity may thus control terrestrial and marine porewater mixing, support SGD, and provide the pathways for groundwater and the materials it transports into the lagoon. This hydrogeophysical investigation highlighted the spatial heterogeneity of submarine coastal geology and its

  5. Helminth communities in eels Anguilla anguilla from Adriatic coastal lagoons in Italy.

    PubMed

    Di Cave, D; Berrilli, F; De Liberato, C; Orecchia, P; Kennedy, C R

    2001-03-01

    The composition and diversity of the total and intestinal component and infra-communities were determined in eels Anguilla anguilla from three shallow lagoons on the Adriatic coast of Italy to determine whether the helminth communities would differ in composition and structure from those in eels from lagoons on the Tyrrhenian coast. The lagoons differed in respect of their management regimes and the extent of freshwater influx. Both freshwater and marine species of helminths were found in the eels in all three lagoons, but the freshwater component was richer in Valle Figheri. A suite of three digenean eel specialist species occurred in all three lagoons, of which any two members dominated each community. This conferred a high degree of similarity between the communities of the three lagoons. The same three species also dominated helminth communities in eels in lagoons along the Tyrrhenian coast of Italy, and compositional similarity levels were similar within and between western and eastern groups. Species richness was higher in the component communities of the eels of the Adriatic lagoons when compared to the Tyrrhenian ones, but diversity and dominance indices were of a similar order of magnitude and range. Intestinal helminth communities were richer and more diverse in two of the Adriatic lagoons because the proportion of eels with zero or one helminth species was, unusually, in the minority. It was nevertheless concluded that infracommunity structure was similar in eels from both western and eastern lagoons and that the hypothesis that it would differ in Adriatic lagoons could not be supported. The findings provide further evidence of the similarity in composition and structure of helminth communities in eels from coastal lagoons throughout Europe.

  6. Saline landfill leachate disposal in facultative lagoons for wastewater treatment.

    PubMed

    Orta de Velasquez, M T; Monje-Ramirez, I; Yañez Noguez, I

    2012-01-01

    This study was carried out to determine the effect of disposing of saline landfill leachates in a Facultative Lagoon Wastewater Treatment Plant (FLWTP). The FLWTP is near a landfill and presents two characteristics: a wastewater influent with low organic matter, and high lagoon salinity due to the soil characteristics. These characteristics made the FLWTP a viable candidate to evaluate the feasibility of adding landfill leachates to the wastewater influent. Different mixtures of leachate with raw wastewater using volumetric ratios of 4%, 6%, and 10% (v/v) were evaluated in facultative lagoon reactors (FLRs). A 10% concentration of leachates in raw wastewater increased BOD5 and COD in the influent from 45 to 110 mg L(-1) and from 219 to 711 mg L(-1), respectively. It was found that the increase in salinity given by the raw wastewater and leachate mixture did not inhibit algae diversity. The types of algae present were Microcystis sp., Merismopedia sp., Euglena sp., Scenedesmus sp., Chlorella, Diatomea and Anacystis sp. However, decreased algae densities were observed, as measured by the decrease in chlorophyll concentration. The results showed that a 100% leachate concentration combined with wastewater did not upset biological treatment in the FLRs. Mean removal efficiencies for BOD5 and COD were 75% and 35%, respectively, giving a final BOD5 lower than 25 mg L(-1). There was also a significant decrease in the leachate heavy metal content when diluted with raw wastewater as result of natural precipitation.

  7. Coastal lagoons and their evolution: A hydromorphological perspective

    NASA Astrophysics Data System (ADS)

    Duck, Robert W.; da Silva, José Figueiredo

    2012-09-01

    From a geoscience perspective, coastal lagoons are essentially ephemeral features which are part of a continuum of coastal environments. Their natural hydromorphological evolution is seldom if ever permitted to take place as a consequence of human action; either directly by engineering interventions, to maintain or create navigable inlets, or indirectly due to activities within their catchment areas. The hydromorphological impacts of historical, contemporary and proposed engineering activities in coastal lagoons around in the world are reviewed and from these a powerful exemplar is that of the Aveiro system in Portugal. Here, two centuries of channelization, jetty and breakwater construction and progressive dredging have transformed a then fluvially dominant system into one that is today tidally dominant. Both the tidal range and tidal prism have increased along with the extent of saline intrusion. The associated stresses imposed by increased tidal currents have, in turn, led to important changes in the sedimentary regime and to the loss of almost all seagrass species which were once abundant in the system. This, along with observations from other related case studies, raises important questions regarding the concept of lagoon ecosystem 'health' and the baseline or reference conditions to which it is assessed.

  8. Plankton bioindicators of environmental conditions in coastal lagoons

    NASA Astrophysics Data System (ADS)

    Hemraj, Deevesh A.; Hossain, Md A.; Ye, Qifeng; Qin, Jian G.; Leterme, Sophie C.

    2017-01-01

    Coastal lagoons are characterised by strong spatial gradient of environmental parameters, especially hypersalinity, and are prone to anthropogenic disturbance. The Coorong (South Australia) is an inverse estuarine coastal lagoon separated from the sea by sand dunes. It is exposed to extreme water quality changes that affect its aquatic communities. Here, we used plankton as indicators of extreme environmental fluctuations to monitor and manage the environmental health of such complex systems. We defined the relationship of different plankton communities with water quality fluctuations and determined plankton species suitable for monitoring the ecosystem health. Two distinct communities of phytoplankton and zooplankton were identified, with salinity and nutrients being the principal factors impacting species distribution. Thus, two sets of indicator species were selected based on the different communities observed. Polychaete and gastropod larvae were positive indicators, showing salinity range restriction of brackish to marine. The distribution Acartia cf. fancetti represented healthy hypersaline conditions (salinity 40-60), while Cyclophora sp. and Scrippsiella sp. were negative indicators, correlating with extreme salinity and ammonia levels. The implementation of planktonic organisms as environmental indicators provided a constructive tool for the management of ecosystem health of the Coorong and will be applicable to similar coastal lagoons.

  9. An integrated Pan-European perspective on coastal Lagoons management through a mosaic-DPSIR approach

    PubMed Central

    Dolbeth, Marina; Stålnacke, Per; Alves, Fátima L.; Sousa, Lisa P.; Gooch, Geoffrey D.; Khokhlov, Valeriy; Tuchkovenko, Yurii; Lloret, Javier; Bielecka, Małgorzata; Różyński, Grzegorz; Soares, João A.; Baggett, Susan; Margonski, Piotr; Chubarenko, Boris V.; Lillebø, Ana I.

    2016-01-01

    A decision support framework for the management of lagoon ecosystems was tested using four European Lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Tyligulskyi Liman (Ukraine) and Vistula Lagoon (Poland/Russia). Our aim was to formulate integrated management recommendations for European lagoons. To achieve this we followed a DPSIR (Drivers-Pressures-State Change-Impacts-Responses) approach, with focus on integrating aspects of human wellbeing, welfare and ecosystem sustainability. The most important drivers in each lagoon were identified, based on information gathered from the lagoons’ stakeholders, complemented by scientific knowledge on each lagoon as seen from a land-sea perspective. The DPSIR cycles for each driver were combined into a mosaic-DPSIR conceptual model to examine the interdependency between the multiple and interacting uses of the lagoon. This framework emphasizes the common links, but also the specificities of responses to drivers and the ecosystem services provided. The information collected was used to formulate recommendations for the sustainable management of lagoons within a Pan-European context. Several common management recommendations were proposed, but specificities were also identified. The study synthesizes the present conditions for the management of lagoons, thus analysing and examining the activities that might be developed in different scenarios, scenarios which facilitate ecosystem protection without compromising future generations. PMID:26776151

  10. Decrease in herbicide concentrations and affected factors in lagoons located around Lake Biwa.

    PubMed

    Sudo, M; Nishino, M; Okubo, T

    2006-01-01

    The contamination levels and changes in the concentrations in four lagoons around Lake Biwa of paddy-use herbicide were studied. Four lagoons, Sone-numa (52 days of HRT (hydraulic residence time) estimated from the lagoon volume and the average discharge at the outlet, 21 ha area), Yanagihira-ko (40 days, 5.0 ha), Noda-numa (11 days, 6.0 ha), and Iba-naiko (2 days, 55.5 ha), were selected as monitoring sites. Intensive water sampling was carried out once a week from May to June at the outlet of each lagoon. Although twelve of the monitored herbicides were detected, the maximum concentrations did not exceed the guidelines for water-supply law in Japan. The relation between half-lives in herbicide concentrations and characteristics of a lagoon such as HRT and chlorophyll-a concentrations were examined. The shorter half-lives of herbicide concentrations in lagoons with shorter HRT means that replacement by influent water effectively decreased the pesticide concentrations. Shorter half-lives in lagoons with high chlorophyll-a concentrations between the lagoons with similar HRT suggest that biological degradation during the residence time worked more efficiently in the lagoon with high chlorophyll-a concentrations.

  11. Spatiotemporal variation of bacterial community composition and possible controlling factors in tropical shallow lagoons.

    PubMed

    Laque, Thaís; Farjalla, Vinicius F; Rosado, Alexandre S; Esteves, Francisco A

    2010-05-01

    Bacterial community composition (BCC) has been extensively related to specific environmental conditions. Tropical coastal lagoons present great temporal and spatial variation in their limnological conditions, which, in turn, should influence the BCC. Here, we sought for the limnological factors that influence, in space and time, the BCC in tropical coastal lagoons (Rio de Janeiro State, Brazil). The Visgueiro lagoon was sampled monthly for 1 year and eight lagoons were sampled once for temporal and spatial analysis, respectively. BCC was evaluated by bacteria-specific PCR-DGGE methods. Great variations were observed in limnological conditions and BCC on both temporal and spatial scales. Changes in the BCC of Visgueiro lagoon throughout the year were best related to salinity and concentrations of NO (3) (-) , dissolved phosphorus and chlorophyll-a, while changes in BCC between lagoons were best related to salinity and dissolved phosphorus concentration. Salinity has a direct impact on the integrity of the bacterial cell, and it was previously observed that phosphorus is the main limiting nutrient to bacterial growth in these lagoons. Therefore, we conclude that great variations in limnological conditions of coastal lagoons throughout time and space resulted in different BCCs and salinity and nutrient concentration, particularly dissolved phosphorus, are the main limnological factors influencing BCC in these tropical coastal lagoons.

  12. An integrated Pan-European perspective on coastal Lagoons management through a mosaic-DPSIR approach

    NASA Astrophysics Data System (ADS)

    Dolbeth, Marina; Stålnacke, Per; Alves, Fátima L.; Sousa, Lisa P.; Gooch, Geoffrey D.; Khokhlov, Valeriy; Tuchkovenko, Yurii; Lloret, Javier; Bielecka, Małgorzata; Różyński, Grzegorz; Soares, João A.; Baggett, Susan; Margonski, Piotr; Chubarenko, Boris V.; Lillebø, Ana I.

    2016-01-01

    A decision support framework for the management of lagoon ecosystems was tested using four European Lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Tyligulskyi Liman (Ukraine) and Vistula Lagoon (Poland/Russia). Our aim was to formulate integrated management recommendations for European lagoons. To achieve this we followed a DPSIR (Drivers-Pressures-State Change-Impacts-Responses) approach, with focus on integrating aspects of human wellbeing, welfare and ecosystem sustainability. The most important drivers in each lagoon were identified, based on information gathered from the lagoons’ stakeholders, complemented by scientific knowledge on each lagoon as seen from a land-sea perspective. The DPSIR cycles for each driver were combined into a mosaic-DPSIR conceptual model to examine the interdependency between the multiple and interacting uses of the lagoon. This framework emphasizes the common links, but also the specificities of responses to drivers and the ecosystem services provided. The information collected was used to formulate recommendations for the sustainable management of lagoons within a Pan-European context. Several common management recommendations were proposed, but specificities were also identified. The study synthesizes the present conditions for the management of lagoons, thus analysing and examining the activities that might be developed in different scenarios, scenarios which facilitate ecosystem protection without compromising future generations.

  13. The effect of floods on sediment contamination in a microtidal coastal lagoon: the lagoon of Lesina, Italy.

    PubMed

    D'Adamo, Raffaele; Specchiulli, Antonietta; Cassin, Daniele; Botter, Margherita; Zonta, Roberto; Fabbrocini, Adele

    2014-10-01

    The effects on the microtidal lagoon of Lesina of runoff and the discharge of water and material from agricultural activities were investigated combining chemical analyses of pollutants [11 metals and 16 priority polycyclic aromatic compounds (PAHs)], determination of organic matter and grain size, and performance of innovative ecotoxicological tests. For metals, enrichment factors >3 for arsenic, nickel, and copper (Cu) were observed in the eastern zone of the lagoon, which is affected by nearby urban activities with discharge of water and domestic waste and by agricultural input with waters rich in fertilizers. Cu was correlated with no other metal, and its high concentrations (≤77 µg g(-1)) may result from the use of Cu-based fungicides in vineyards. Total PAHs (2,230 ± 3,150 ng g(-1)) displayed a wide range of concentrations with hot spots near freshwater inputs from the part of the catchment area exploited for wheat crops. Pyrolitic contamination also emerged, with higher-mass PAH congeners, such as asphalt, bitumen or coal, usually present in higher fractions as the dominant components. Ecotoxicological evaluations recorded moderate to high toxicity levels; the innovative MOT test bioassay showed good discriminatory ability because it identified a lagoon area whose inputs mainly depend on agricultural activities and which is impacted by metals rather than PAHs. Floods during periods of heavy rain and the discharge of water and material from agricultural activities may impact vulnerable systems, such as the lagoon of Lesina, where the presence of hot spots with remarkably high pollution values was observed.

  14. Depositional history and fault-related studies, Bolinas Lagoon, California

    USGS Publications Warehouse

    Berquist, Joel R.

    1978-01-01

    Studies of core sediments and seismic reflection profiles elucidate the structure and depositional history of Bolinas Lagoon, Calif., which covers 4.4 km 2 and lies in the San Andreas fault zone at the southeast corner of the Point Reyes Peninsula 20 km northwest of San Francisco. The 1906 trace of the San Andreas fault crosses the west side of the lagoon and was determined from (1) tectonically caused salt-marsh destruction indicated by comparison of 1854 and 1929 U.S. Coast and Geodetic Survey (U.S.C. & G.S.) topographic surveys, (2) formation of a tidal channel along the border of destroyed salt marshes, and (3) azimuths of the trend of the fault measured in 1907. Subsidence in the lagoon of 30 cm occurred east of the San Andreas fault in 1906. Near the east shore, seismic-reflection profiling indicates the existence of a graben fault that may connect to a graben fault on the Golden Gate Platform. Comparison of radiocarbon dates on shells and plant debris from boreholes drilled on Stinson Beach spit with a relative sea-level curve constructed for southern San Francisco Bay indicates 5.8 to more than 17.9 m of tectonic subsidence of sediments now located 33 m below mean sea level. Cored sediments indicate a marine transgression dated at 7770?65 yrs B.P. overlying freshwater organic-rich lake deposits. Fossil pollen including 2 to 8 percent Picea (spruce) indicate a late Pleistocene (?)-Early Holocene climate, cooler, wetter, and foggier than at present. Above the transgression are discontinuous and interfingering sequences of transgressive-regressive marine, estuarine, and barrier sediments that reflect rapid lateral and vertical shifts of successive depositional environments. Fossil megafauna indicate (1) accumulation in a protected, shallow-water estuary or bay, and (2) that the lagoon was probably continuously shallow and never a deep-water embayment. Analysis of grain-size parameters, pollen frequencies, and organic remains from a core near the north end of

  15. Seasonal Variation of the Macrozoobenthic Community Structure at Low Salinities in a Mediterranean Lagoon (Monolimni Lagoon, Northern Aegean)

    NASA Astrophysics Data System (ADS)

    Kevrekidis, Theodoros

    2004-09-01

    The macrozoobenthic community structure and dynamics at low salinities (0.3-6 psu) in a Mediterranean lagoon (Monolimni lagoon) were investigated. Samples were collected monthly from February 1998 to February 1999 at two sampling stations. Community structure was analyzed by means of uni- and multivariate methods. 21 taxa were collected; the amphipod Corophium orientale and the gastropod Ventrosia maritima dominated the assemblages. Total abundance peaked (50,000-60,000 individuals m-2) in mid or late autumn. Community structure showed an almost even seasonal periodicity; seasonal changes were mainly derived from the intense variation in abundance of most species and the non-occurrence of a few ones (e.g. Corophium insidiosum, Polydora ciliata) in spring and summer. Non- occurrence, which led to a depression of the most diversity indices, was possibly the only direct impact of the extremely low salinities (~0.3 psu) on community structure. The main structuring factors of the community in the deeper outer part of the lagoon were water temperature and depth, and in the innermost part, where a Ruppia maritima meadow occurred, were water temperature and predation pressure by crabs (Carcinus aestuarii) and gobies (Knipowitchia caucasica). A temporary decline in total abundance in summer followed an increase in abundance of these predators. (

  16. Measurement of seepage losses and chemical export from waste lagoons at animal feeding operations

    NASA Astrophysics Data System (ADS)

    Ham, J. M.; DeSutter, T. M.

    2001-05-01

    Whole-lagoon seepage rates were measured from 20 lagoons in Kansas using water balance techniques. Study sites included cattle feedlots, swine facilities, and one dairy. Seepage rates ranged from 0.2 mm/day to 2.4 mm/day with and overall average of 1.2 mm/day. Analysis of lagoon effluent (58 samples from 38 sites) indicated large differences in lagoon chemistry between locations. Ammonium nitrogen (NH4-N), which accounted for over 99 percent of the soluble nitrogen, ranged from 10 ppm to 3500 ppm. On average, nitrogen concentrations in swine lagoons were about five times higher than those at cattle feedlots. The chemical flux density (flux boundary condition) was estimated from the seepage rate and the corresponding waste chemistry data from each lagoon. Results showed that ammonium-N export was between 0.02 and 1.06 kg NH4-N m-2 yr^{-1} with an overall average of about 0.3 kg NH4-N m^{-2} yr^{-1}$ . Similar data are available for other soluble compounds. Soil cores were collected beneath eight lagoons that had been operated from 12 to 25 years. Results showed that NH4-N was strongly adsorbed by the soil clay particles and that nitrogen concentrations often decreased to background levels at 3 m beneath the lagoon. Other ions, such as chloride, penetrated to much lower depths at all locations. The 'reservoir' of NH4-N that exists beneath older lagoons could convert to nitrate and move to lower depths after lagoon closure. Data suggest that the properties if the soil beneath lagoons, the concentration of the waste, the seepage rate, and the depth to groundwater are the crucial factors that affect the risk of groundwater contamination.

  17. SUPERFUND TREATABILITY CLEARINGHOUSE: FINAL REPORT: DEVELOPMENT OF OPTIMUM TREATMENT SYSTEM FOR WASTEWATER LAGOONS PHASE II - SOLVENT EXTRACTION LABORATORY TESTING

    EPA Science Inventory

    The U.S. Army surveyed innovative treatment techniques for restoration of hazardous waste lagoons and selected solvent extraction as cost-effective restoration for further study. This treatability study focuses on treatment of organic (explosive) contaminated lagoon sediments w...

  18. Plant growth and elemental uptake by floating vegetation on a single stage swine wastewater lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods are needed for utilizing nutrients contained within animal wastewater lagoons. One potential method for removing nutrients is to have vegetation growing on the lagoon. A study was conducted from 2005-2008 to determine the feasibility of growing vegetation on floating platforms on a single ...

  19. Using floating vegetation to remove nutrients from an anaerobic swine wastewater lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods are needed for utilizing nutrients contained within animal wastewater lagoons. One potential method for removing nutrients is to have vegetation growing in the lagoon. A study was conducted from 2005-2007 to determine the feasibility of growing vegetation on floating platforms on a single ...

  20. Improving estimates of N and P loads in irrigation water from swine manure lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The implementation of nutrient management plans (NMPs) for confined animal feeding operations (CAFOs) requires recording N and P loads from land-applied manure, including nutrients applied in irrigation water from manure treatment lagoons. By regulation, lagoon irrigation water nutrient records in ...

  1. Environmental heterogeneity patterns and assessment of trophic levels in two Mediterranean lagoons: Orbetello and Varano, Italy.

    PubMed

    Specchiulli, Antonietta; Focardi, Silvia; Renzi, Monia; Scirocco, Tommaso; Cilenti, Lucrezia; Breber, Paolo; Bastianoni, Simone

    2008-09-01

    The management of coastal lagoons is of particular interest due to their high economical importance. In spite of their great productivity, coastal lagoons are often impacted by human pressure which produces water eutrophication. The aim of this paper is to assess the trophic state of the two Mediterranean lagoons taking into account chemical-physical parameters, nutrient concentrations and biological parameters. Two Italian lagoons, Orbetello and Varano (respectively located in Tyrrhenian and Adriatic coast, Italy) were studied between May 2003 and April 2005. Both these systems receive treated urban outflows, agricultural effluents and rivers freshwater inputs. Field collected data showed that studied lagoons were characterized by different human and natural pressures. Orbetello showed the highest water eutrophication, highlighted by the trophic index values, while Varano showed lower eutrophication levels except for the summertime. The values of physical, chemical and biological parameters measured in Orbetello and Varano lagoons indicate that a wide spatial and seasonal gradient of the water characteristics was established during the study period, but in particular in winter. This gradient, typical of estuarine systems, was essentially due to the mixing of freshwater, seawater and anthropogenic inputs. Orbetello lagoon seemed much more affected by the urban impact and the fish-farming activities than Varano lagoon, but the latter showed a greater agriculture activities impact as showed by the remote sensing images.

  2. Decline of phosphorus, copper, and zinc in anaerobic lagoon columns receiving pretreated influent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Confined swine production generates large volumes of wastewater typically stored and treated in anaerobic lagoons. These lagoons usually require a sludge management plan for their maintenance consisting of regular sludge removal by mechanical agitation and pumping followed by land application at agr...

  3. Survival of Salmonella enterica in aerated and nonaerated wastewaters from dairy lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces end up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped with...

  4. Changes in sludge accumulation of anaerobic swine lagoons receiving pretreated influent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the changes in sludge depth and volume of anaerobic swine lagoon in North Carolina after six years of applying treatment to the liquid flushed manure prior to entering the lagoon. The farm had seven swine barns with a permitted capacity of 5,145 head feeder to finish (735 head/b...

  5. Methane and ammonia emissions from New Mexico dairy lagoons in summer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gaseous emissions of concern from commercial dairy operations include methane and ammonia. Dairy wastewater lagoons are sources of emission for both these gases. We quantified emissions of methane and ammonia from a lagoon system at a commercial open lot dairy in eastern New Mexico using open path l...

  6. Measuring gas emissions from animal waste lagoons with an inverse-dispersion technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measuring gas emissions from treatment lagoons and storage ponds poses challenging conditions for existing micrometeorological techniques due to non-ideal conditions such as trees and crops surrounding the lagoons, and short fetch to establish equilibrated microclimate conditions within the water bo...

  7. Microbial community analysis of swine wastewater anaerobic lagoons by next-generation DNA sequencing.

    PubMed

    Ducey, Thomas F; Hunt, Patrick G

    2013-06-01

    Anaerobic lagoons are a standard practice for the treatment of swine wastewater. This practice relies heavily on microbiological processes to reduce concentrated organic material and nutrients. Despite this reliance on microbiological processes, research has only recently begun to identify and enumerate the myriad and complex interactions that occur in this microbial ecosystem. To further this line of study, we utilized a next-generation sequencing (NGS) technology to gain a deeper insight into the microbial communities along the water column of four anaerobic swine wastewater lagoons. Analysis of roughly one million 16S rDNA sequences revealed a predominance of operational taxonomic units (OTUs) classified as belonging to the phyla Firmicutes (54.1%) and Proteobacteria (15.8%). At the family level, 33 bacterial families were found in all 12 lagoon sites and accounted for between 30% and 50% of each lagoon's OTUs. Analysis by nonmetric multidimensional scaling (NMS) revealed that TKN, COD, ORP, TSS, and DO were the major environmental variables in affecting microbial community structure. Overall, 839 individual genera were classified, with 223 found in all four lagoons. An additional 321 genera were identified in sole lagoons. The top 25 genera accounted for approximately 20% of the OTUs identified in the study, and the low abundances of most of the genera suggests that most OTUs are present at low levels. Overall, these results demonstrate that anaerobic lagoons have distinct microbial communities which are strongly controlled by the environmental conditions present in each individual lagoon.

  8. The Defense Committees of Sleepy Lagoon: A Convergent Struggle against Fascism, 1942-1944

    ERIC Educational Resources Information Center

    Barajas, Frank P.

    2006-01-01

    The Sleepy Lagoon Defense Committee originated as an ad hoc committee and evolved to a broad-based movement for legal justice on behalf of seventeen youth convicted of murder and assault charges in connection with the Sleepy Lagoon case in Los Angeles in January 1943. This essay chronicles the multidimensional organizing to shift public opinion in…

  9. Increased bioavailability of mercury in the lagoons of Lomb, Togo: the possible role of dredging.

    PubMed

    Gnandi, Kissao; Han, Seunghee; Rezaie-Boroon, M Hassan; Porrachia, Magali; Deheyn, Dimitri D

    2011-02-01

    Surface sediments of the lagoons of Lomé, Togo, were analyzed for mercury, methylmercury, and trace elements. Concentrations were greater than typical for natural lagoon sediments, and with greater variability within the Eastern lagoon compared to the Western one. The Eastern lagoon is larger and has been dredged in the past, while the Western lagoon, which also receives major waste inputs, has not been dredged and shows less tidal flushing. Accordingly, one naturally believes that the Eastern lagoon is cleaner and probably safe to use due to its natural resources, including fishes to eat. Unexpectedly, we describe here that mercury methylation was greater in the Eastern lagoon, indicating increased bioavailability of mercury, as probably facilitated by past dredging that decreased solid-phase retention of inorganic mercury. Urbanization has historically been more developed in the southern part of the lagoons, which is still reflected in contamination levels of sediment despite dredging, probably because sources of contamination are still more important there today. Such urban contamination emphasizes the need to regulate waste discharges and possible airborne contamination in growing cities of developing countries, and implements environmental and public health monitoring, especially in relation to misbelieves systematically associated with the cleansing effect of dredging activity.

  10. Assessment of the environmental quality of French continental Mediterranean lagoons with oyster embryo bioassay.

    PubMed

    Galgani, F; Senia, J; Guillou, J L; Laugier, T; Munaron, D; Andral, B; Guillaume, B; Coulet, E; Boissery, P; Brun, L; Bertrandy, M C

    2009-10-01

    In order to better understand environmental disturbances in the French coastal Mediterranean lagoons, we used an ecotoxicological approach based on the measurement of the toxicity of the sediments using oyster embryo bioassay that provides a basis for assessing the effects on the fauna of contaminants adsorbed on the sedimentary particles. The study covers all of the main lagoons of the French Mediterranean coasts of Languedoc Roussillon, Camargue, and Provence (Berre and Bolmon lagoons), where 188 stations were sampled. The toxicity tests provide evidence of variable levels of toxicity in sediments. Contaminated lagoons such as La peyrade, Le canet, and Ingrill and locally affected lagoons such as Bages-Sigean, Vaccares, Bolmon, and Berre have sampling stations with 100% of larval abnormalities during 24-h development. In all of the lagoons, the toxicity was mainly located close to local harbors and rivers. Salses Leucate (Languedoc roussillon) lagoon was found very clean, with no important toxicity. The results are discussed in terms of environmental disturbances of the coastal lagoons and with regard to the long-term monitoring of the impact of contaminants on the coastal environment.

  11. 75 FR 53960 - Chignik Lagoon Power Utility; Notice of Declaration of Intention and Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ... Energy Regulatory Commission Chignik Lagoon Power Utility; Notice of Declaration of Intention and... Lagoon Power Utility. e. Name of Project: Packers Creek Hydroelectric Project. f. Location: The proposed Packers Creek Hydroelectric Project will be located on Packers Creek, near the community of Chignik...

  12. Developing a model for the mercury cycle in the Marano-Grado Lagoon (Italy)

    EPA Science Inventory

    The Marano-Grado Lagoon is a wetland system of about 160 km2 located in the Northern Adriatic Sea (Italy) between the Tagliamento and the Isonzo River mouths. The lagoon morphology and biogeochemistry are primarily controlled by the exchange with the Adriatic Sea and, to a lesser...

  13. Influence of nutrient input on the trophic state of a tropical brackish water lagoon

    NASA Astrophysics Data System (ADS)

    Ganguly, D.; Patra, Sivaji; Muduli, Pradipta R.; Vardhan, K. Vishnu; R, Abhilash K.; Robin, R. S.; Subramanian, B. R.

    2015-07-01

    Ecosystem level changes in water quality and biotic communities in coastal lagoons have been associated with intensification of anthropogenic pressures. In light of incipient changes in Asia's largest brackish water lagoon (Chilika, India), an examination of different dissolved nutrients distribution and phytoplankton biomass, was conducted through seasonal water quality monitoring in the year 2011. The lagoon showed both spatial and temporal variation in nutrient concentration, mostly altered by freshwater input, regulated the chlorophyll distribution as well. Dissolved inorganic N:P ratio in the lagoon showed nitrogen limitation in May and December, 2011. Chlorophyll in the lagoon varied between 3.38 and 17.66 mg m -3. Spatially, northern part of the lagoon showed higher values of DIN and chlorophyll during most part of the year, except in May, when highest DIN was recorded in the southern part. Statistical analysis revealed that dissolved NH-N and urea could combinedly explain 43% of Chlorophyll- a (Chl- a) variability which was relatively higher than that explained by NO-N and NO-N (12.4%) in lagoon water. Trophic state index calculated for different sectors of the lagoon confirmed the inter-sectoral and inter-seasonal shift from mesotrophic to eutrophic conditions largely depending on nutrient rich freshwater input.

  14. Dynamics of copper and zinc sedimentation in a lagooning system receiving landfill leachate.

    PubMed

    Guigue, Julien; Mathieu, Olivier; Lévêque, Jean; Denimal, Sophie; Steinmann, Marc; Milloux, Marie-Jeanne; Grisey, Hervé

    2013-11-01

    This study characterises the sediment dredged from a lagooning system composed of a settling pond and three lagoons that receive leachates from a municipal solid waste (MSW) landfill in France. Organic carbon, carbonate, iron oxyhydroxides, copper (Cu) and zinc (Zn) concentrations were measured in the sediment collected from upstream to downstream in the lagooning system. In order to complete our investigation of sedimentation mechanisms, leachates were sampled in both dry (spring) and wet (winter) seasonal conditions. Precipitation of calcite and amorphous Fe-oxyhydroxides and sedimentation of organic matter occurred in the settling pond. Since different distributions of Zn and Cu concentrations are measured in sediment samples collected downstream in the lagooning system, it is suggested that these elements were not distributed in a similar way in the leachate fractions during the first stage of treatment in the settling pond, so that their sedimentation dynamics in the lagooning system differ. In the lagoons, it was found that organic carbon plays a major role in Cu and Zn mobility and trapping. The presence of macrophytes along the edges provided an input of organic matter that enhanced Cu and Zn scavenging. This edge effect resulted in a two-fold increase in Cu and Zn concentrations in the sediment deposited near the banks of the lagoons, thus confirming the importance of vegetation for the retention of Cu and Zn in lagooning systems.

  15. Induction of Purple Sulfur Bacterial Growth in Dairy Wastewater Lagoons by Circulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: To determine if circulation of diary wastewater induces the growth of phototrophic purple sulfur bacteria (PSB). Methods and Results: Two dairy wastewater lagoons that were similar in size, geographic location, number and type of cattle loading the lagoons were chosen. The only obvious diffe...

  16. Plankton community dynamics in a subtropical lagoonal system and related factors.

    PubMed

    Donadel, Letícia; Cardoso, Luciana de S; Torgan, Lezilda C

    2016-03-01

    Changes of the plankton community in a shallow, subtropical lagoonal system and its relation to environmental conditions were investigated during an annual cycle to provide information on its spatial and seasonal variation pattern. The study carried out at four sites (three in the Peixe lagoon and one in the Ruivo lagoon), which are located in the Lagoa do Peixe National Park, southern Brazil. The system has a temporary connection to the Atlantic Ocean by a narrow channel. The phytoplankton density was higher in the Peixe lagoon whereas the specific richness was higher in the Ruivo lagoon which is also a site with the lower salinity. The phytoplankton biomass near the channel showed seasonal variation with the highest value in fall and lowest in winter. Zooplankton richness was inversely correlated with salinity, and had the highest values in the Ruivo lagoon. Ordination analysis indicated seasonal and spatial patterns in plankton community in this lagoonal system, related to variation in salinity. In addition, the wind action and precipitation were important factors on the spatial and seasonal salinity changes in the lagoon with direct influence on the plankton community dynamics.

  17. Improving N and P estimates for swine manure lagoon irrigation water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrient management plans (NMPs) for confined animal feeding operations (CAFOs) require a record of N and P loads from manure land-applications, including irrigation with lagoon water. Mississippi regulations require nutrient records for lagoon irrigation water be based on at least one annual analy...

  18. Project summary. PERSISTENCE OF PATHOGENS IN LAGOON-STORED SLUDGE (EPA/600/S2-89/015)

    EPA Science Inventory

    The project objective was to investigate pathogen inactlvation in lagoon-stored municipal sludges. The in-field lagoons were located in Louisiana (New Orleans) and in Texas (Port Aransas), both semitropical areas of the United States. Each lagoon was filled with 7.56 mL of ...

  19. Evidence of North Africa’s Green Revolution Preserved in Sedimentary Organic Matter Deposited in Three Coastal Lagoons.

    EPA Science Inventory

    Because of longer residence times and limited mixing in coastal lagoons, the impacts of anthropogenic nutrient loading to lagoon food webs are often more pronounced than in other coastal ecosystems. For these reasons, many lagoons also provide an excellent environment for the dep...

  20. Seasonal variation in heat fluxes, predicted emissions of malodorants, and wastewater quality of an anaerobic swine waste lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concentrations of p-cresol above a wastewater lagoon were modeled from February through June based on equations developed in a previous study. Using this model, in which p-cresol concentrations were calculated based on lagoon evaporation and net available radiation at the lagoon surface, predic...

  1. Identifying tsunami deposits using shell taphonomy: Sur lagoon, Oman

    NASA Astrophysics Data System (ADS)

    Donato, S.; Reinhardt, E.; Rothaus, R.; Boyce, J.

    2007-05-01

    On November 28th, 1945 an 8.1 magnitude earthquake focused in the eastern portion of the Makran subduction zone (Arabian Sea) generated a powerful tsunami that destroyed many coastal villages in Pakistan and India. Reports indicate that the tsunami also caused significant damage in Muscat, Oman, although its effects elsewhere in Oman are unknown. A thick bivalve dominated shell horizon was discovered inside the Sur lagoon, which is located on the eastern promontory of Oman (200 km south of Muscat). This shell deposit is significant because it is laterally extensive (> 1 km2), extends deep within the lagoon (>2 km), ranges in thickness from 5 - 25 cm at the sample localities, contains numerous subtidal and offshore bivalve species, and articulated subtidal and offshore bivalve species are abundant. Although there is an absence of typical tsunami indicators such as allochthonous sediment in and around the lagoon, verbal accounts, cultural evidence recovered during coring, and the absence of strong storms during the past 100 years indicates that this shell unit was caused by the 1945 tsunami. In this setting, it would be advantageous to have another proxy for tsunami detection and risk prediction. The use of shell taphonomy is one of the potential indicators and here we present new evidence of its utility. We sampled this unit in eight locations, and compared the shell taphonomy to surface shell samples collected from beach and reworked horizons in the lagoon, and to shell samples from a known tsunami and corresponding storm/ballast deposit in Israel (Reinhardt et al., 2006). Taphonomic analysis yielded promising results, as the two tsunami horizons shared excellent agreement between the amount of fragmented shells, and the percentage of shells displaying angular breaks. Both of these categories were significantly different from the percentage of fragments and angular fragments recovered from the reworked, beach, and storm/ballast deposits, indicating different

  2. [Ne V] Emission in Optically Classified Starbursts

    NASA Astrophysics Data System (ADS)

    Abel, N. P.; Satyapal, S.

    2008-05-01

    Detecting active galactic nuclei (AGNs) in galaxies dominated by powerful nuclear star formation and extinction effects poses a unique challenge. Due to the longer wavelength emission and the ionization potential of Ne4+, infrared [Ne V] emission lines are thought to be excellent AGN diagnostics. However, stellar evolution models predict that Wolf-Rayet stars in young stellar clusters emit significant numbers of photons capable of creating Ne4+. Recent observations of [Ne V] emission in optically classified starburst galaxies require us to investigate whether [Ne V] can arise from star formation activity and not an AGN. In this work, we calculate the optical and IR spectrum of gas exposed to a young starburst and AGN SED. We find: (1) a range of parameters where [Ne V] emission can be explained solely by star formation and (2) a range of relative AGN to starburst luminosities that reproduces the [Ne V] observations, yet leaves the optical spectrum looking like a starburst. We also find that infrared emission-line diagnostics are much more sensitive to the AGNs than optical diagnostics, particularly for weak AGNs. We apply our model to the optically classified, yet [Ne V] emitting, starburst galaxy NGC 3621. We find, when taking the infrared and optical spectrum into account, ~30%-50% of the galaxy's total luminosity is due to an AGN. Our calculations show that [Ne V] emission is almost always the result of AGN activity. The models presented in this work can be used to determine the AGN contribution to a galaxy's power output.

  3. Sedimentary lipid biogeochemistry of an hypereutrophic alkaline lagoon

    SciTech Connect

    Grimalt, J.O.; Albaiges, J. ); Yruela, I.; Saizjimenez, C. ); Toja, J. ); Leeuw, J.W. De. )

    1991-09-01

    A detailed study of the lipid composition of sedimentary and water particulate samples of a dilute alkaline lake (Santa Olalla Lagoon, Guadalquivir Delta, southwestern Spain) has allowed the identification and quantitation of about 300 compounds reflecting predominant inputs of organic matter and very early diagenetic processes. These lipids, dominated by fatty acids (80-86%), account for up to 0.25% wt. of dry sediment which is consistent with the high eutrophic conditions of the lagoon and suggests a good preservation of the originally produced organic matter. However, the primary lipid compounds, mainly from cyanobacterial origin, are strongly modified. The C{sub 30}-C{sub 32}, 1,13- and 1,15-diols constitute the only major group that can be attributed directly to these organisms. The predominant lipids, including the fatty acids, are indicative of intense microbial reworking, namely contributions from gram-positive and gram-negative eubacteria and methanogens. Conversely, the higher plant lipids are better preserved and dominate the aliphatic hydrocarbon fraction. Hydrogenation and dehydration are two major transformation processes in the sedimentary system being reflected in the transformation of sterols into 5{alpha}(H)- and 5{beta}(H)-stanols and sterenes, and 17{beta}(H), 21{beta}(H)-hopan-22-ol into diploptene. Oxidation in the water column seems to involve the partial transformation of sterols into steroid ketones, phytol into 5,9,13-trimethyltetradecanoic acid and two isomeric 3,7,11,15-tetramethyl-17-hexadecanolides, and, possibly, tetrahymanol into gammacer-3-one. Adiantone and bishomohopanoic acid probably result from the partial oxydation of extended polyhydroxyhopanes or the C{sub 30}-C{sub 33} hydroxyhopanes found in the lagoon waters.

  4. Sedimentary lipid biogeochemistry of an hypereutrophic alkaline lagoon

    NASA Astrophysics Data System (ADS)

    Grimalt, J. O.; Yruela, I.; Saiz-Jimenez, C.; Toja, J.; de Leeuw, J. W.; Albaigés, J.

    1991-09-01

    A detailed study of the lipid composition of sedimentary and water particulate samples of a dilute alkaline lake (Santa Olalla Lagoon, Guadalquivir Delta, southwestern Spain) has allowed the identification and quantitation of about 300 compounds reflecting predominant inputs of organic matter and very early diagenetic processes. These lipids, dominated by fatty acids (80-86%), account for up to 0.25% wt. of dry sediment which is consistent with the high eutrophic conditions of the lagoon and suggests a good preservation of the originally produced organic matter. However, the primary lipid compounds, mainly from cyanobacterial origin, are strongly modified. The C30-C32, 1,13- and 1,15-diols constitute the only major group that can be attributed directly to these organisms. The predominant lipids, including the fatty acids, are indicative of intense microbial reworking, namely contributions from gram-positive and gram-negative eubacteria and methanogens. Conversely, the higher plant lipids are better preserved and dominate the aliphatic hydrocarbon fraction. Hydrogenation and dehydration are two major transformation processes in the sedimentary system being reflected in the transformation of sterols into 5α(H)- and 5β(H)-stanols and sterenes, and 17β(H),21β(H)-hopan-22-ol into diploptene. Oxidation in the water column seems to involve the partial transformation of sterols into steroid ketones, phytol into 5,9,13-trimethyltetradecanoic acid and two isomeric 3,7,11,15-tetramethyl-17-hexadecanolides, and, possibly, tetrahymanol into gammacer-3-one. Adiantone and bishomohopanoic acid probably result from the partial oxydation of extended polyhydroxyhopanes or the C30-C33 hydroxyhopanes found in the lagoon waters.

  5. Survival of Salmonella enterica in aerated and nonaerated wastewaters from dairy lagoons.

    PubMed

    Ravva, Subbarao V; Sarreal, Chester Z

    2014-10-29

    Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces ends up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped or not with circulating aerators at two dairies. All strains had poor survival rates and none proliferated in waters from aerated or settling lagoons. Populations of all three Salmonella serovars declined rapidly with decimal reduction times (D) of <2 days in aerated microcosms prepared from lagoon equipped with circulators. Populations of Salmonella decreased significantly in aerated microcosms (D = 4.2 d) compared to nonaerated waters (D = 7.4 d) and in summer (D = 3.4 d) compared to winter (D = 9.0 d). We propose holding the wastewater for sufficient decimal reduction cycles in lagoons to yield pathogen-free nutrient-rich water for crop irrigations and fertilization.

  6. Redistribution of fallout radionuclides in Enewetak Atoll lagoon sediments by callianassid bioturbation.

    PubMed

    McMurtry, G M; Schneider, R C; Colin, P L; Buddemeier, R W; Suchanek, T H

    The lagoon sediments of Enewetak Atoll in the Marshall Islands contain a large selection of fallout radionuclides as a result of 43 nuclear weapon tests conducted there between 1948 and 1958. Studies of the burial of fallout radionuclides have been conducted on the islands and in several of the large craters, but studies of their vertical distribution have been limited to about the upper 20 cm of the lagoon sediments. We have found elevated fallout radionuclide concentrations buried more deeply in the lagoon sediments and evidence of burrowing into the sediment by several species of callianassid ghost shrimp (Crustacea: Thalassinidea) which has displaced highly radioactive sediment. The burrowing activities of callianassids, which are ubiquitous on the lagoon floor, facilitate radionuclide redistribution and complicate the fallout radionuclide inventory of the lagoon.

  7. Modelling of oxygen and nitrogen cycling as a function of macrophyte community in the Thau lagoon

    NASA Astrophysics Data System (ADS)

    Plus, M.; Chapelle, A.; Lazure, P.; Auby, I.; Levavasseur, G.; Verlaque, M.; Belsher, T.; Deslous-Paoli, J.-M.; Zaldívar, J.-M.; Murray, C. N.

    2003-11-01

    A three-dimensional model coupling physical and biological processes for the whole Thau lagoon (Mediterranean coast of France) was developed in order to assess the relationships between macrophytes and the oxygen and nitrogen cycles. Ten species have been inserted as forcing variables in the model. Plankton dynamics, shellfish cultivation impact and mineralization of organic matter are also considered, as well as nutrient and oxygen exchanges between the sediment and the water column. Simulations with and without the macrophytes have shown that the system can be characterized as having a highly structured pattern involving lagoon nitrogen and oxygen cycles. This pattern is created by the combined influence of macrophytes, watershed and oyster farming. The model has been also used to assess the total annual macrophyte production at the whole lagoon scale. Comparisons with phytoplankton production and with results from other temperate lagoons have underlined the high productivity of the Thau lagoon supported by active nutrient regeneration.

  8. The role of benthic macrophytes and their associated macroinvertebrate community in coastal lagoon resistance to eutrophication.

    PubMed

    Lloret, Javier; Marín, Arnaldo

    2009-12-01

    Eutrophication is widely recognised as one of the major menaces to coastal environments, particularly enclosed bays and lagoons. Although there is a general understanding of the consequences of eutrophication in these systems, there is a lack of sufficient knowledge concerning biotic feedbacks that influence eutrophication patterns and the resistance capacity of coastal environments. In this paper, the isotope ratios of main producers and consumers of a Mediterranean lagoon were examined in order to elucidate the fate of anthropogenic inputs from the main watercourse flowing into the lagoon. The results of the study of stable isotope data in the Mar Menor lagoon reflected that the whole benthic community plays an important role as a natural 'filter' that removes excess nutrients from the water column and stores them in the sediments, thereby enhancing lagoon resistance to eutrophication.

  9. News from KM3NeT

    SciTech Connect

    Katz, Ulrich F.; Collaboration: KM3NeT Collaboration

    2014-11-18

    KM3NeT is a future research infrastructure in the Mediterranean Sea, hosting a multi-cubic-kilometre neutrino telescope and nodes for Earth and Sea sciences. In this report we shortly summarise the genesis of the KM3NeT project and present key elements of its technical design. The physics objectives of the KM3NeT neutrino telescope and some selected sensitivity estimates are discussed. Finally, some first results from prototype operations and the next steps towards implementation – in particular the first construction phase in 2014/15 – are described.

  10. Algal fossils from a late precambrian, hypersaline lagoon.

    PubMed

    Oehler, D Z; Oehler, J H; Stewart, A J

    1979-07-27

    Organically preserved algal microfossils from the Ringwood evaporite deposit in the Gillen Member of the Bitter Springs Formation (late Precambrian of central Australia) are of small size, low diversity, and probable prokaryotic affinities. These rather primitive characteristics appear to reflect the stressful conditions that prevailed in a periodically stagnant, hypersaline lagoon. This assemblage (especially in comparison with the much more diverse assemblages preserved in the Loves Creek Member of the same formation) illustrates the potential utility of Proterozoic microbiotas for basin analysis and local stratigraphic correlation and demonstrates the need to base evolutionary considerations and Precambrian intercontinental biostratigraphy on biotas that inhabited less restricted environments.

  11. [Lagoonal and coastal malaria at Cotonou: entomological findings].

    PubMed

    Akogbéto, M

    2000-01-01

    Nowadays, malaria control is planned according to the epidemiological context. Various aspects of malaria have been described in sub-Saharan Africa. We report here entomological data from the coastal area of Benin, West Africa, which has many lakes and lagoons. We carried out a longitudinal study in which we investigated the dynamics of populations of malaria vectors in various zones, the frequency of inoculation in these zones, the infestation rate of the Anopheles gambiae mosquitoes collected, the effect of urbanization on malaria transmission, the effects of inundation and of salinity at mosquito breeding sites. A total of 3, 342 identifications were made on a chromosomal basis. Two species of the Anopheles gambiae complex were detected in the coastal and lagoon areas of Benin: An. melas and An. gambiae ss. The density of the populations of these species was highly dependent on the level of urbanization. In traditional villages on the lagoons (such as Agbalilamè, Djegbadji and Kétonou), the density of An. melas (86. 2%) was much higher than that in more urbanized areas (such as Ladji and Abomey-Calavi) (4.9%). We checked for chromosome polymorphism. We detected a 2Rn1 inversion in An. melas, similar to the 2Rn inversion found in mosquitoes in Gambia and Guinea-Bissau. The frequency of the n1 inversion and the density of An. melas populations were correlated and both seemed to depend on a single factor, salinity. The epidemiological situation with respect to malaria was very heterogeneous in the lagoon area of Benin. In the city of Cotonou, transmission was seasonal, sporozoite indices and the frequency of inoculation were high, in contrast to what would normally be expected in an urban area. In communities built on the beach, the level of transmission was markedly lower: about 5 infected bites per person per year versus 29 infected bites per person in the center of the city. In the traditional fishing villages, a paradoxical situation was observed in which the

  12. First steps of ecological restoration in Mediterranean lagoons: Shifts in phytoplankton communities

    NASA Astrophysics Data System (ADS)

    Leruste, A.; Malet, N.; Munaron, D.; Derolez, V.; Hatey, E.; Collos, Y.; De Wit, R.; Bec, B.

    2016-10-01

    Along the French Mediterranean coast, a complex of eight lagoons underwent intensive eutrophication over four decades, mainly related to nutrient over-enrichment from continuous sewage discharges. The lagoon complex displayed a wide trophic gradient from mesotrophy to hypertrophy and primary production was dominated by phytoplankton communities. In 2005, the implementation of an 11 km offshore outfall system diverted the treated sewage effluents leading to a drastic reduction of anthropogenic inputs of nitrogen and phosphorus into the lagoons. Time series data have been examined from 2000 to 2013 for physical, chemical and biological (phytoplankton) variables of the water column during the summer period. Since 2006, total nitrogen and phosphorus concentrations as well as chlorophyll biomass strongly decreased revealing an improvement in lagoon water quality. In summertime, the decline in phytoplankton biomass was accompanied by shifts in community structure and composition that could be explained by adopting a functional approach by considering the common functional traits of the main algal groups. These phytoplankton communities were dominated by functional groups of small-sized and fast-growing algae (diatoms, cryptophytes and green algae). The trajectories of summer phytoplankton communities displayed a complex response to changing nutrient loads over time. While diatoms were the major group in 2006 in all the lagoons, the summer phytoplankton composition in hypertrophic lagoons has shifted towards green algae, which are particularly well adapted to summertime conditions. All lagoons showed increasing proportion and occurrence of peridinin-rich dinophytes over time, probably related to their capacity for mixotrophy. The diversity patterns were marked by a strong variability in eutrophic and hypertrophic lagoons whereas phytoplankton community structure reached the highest diversity and stability in mesotrophic lagoons. We observe that during the re

  13. The NeXus data format

    PubMed Central

    Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.; Brewster, Aaron S.; Campbell, Stuart I.; Clausen, Björn; Cottrell, Stephen; Hoffmann, Jens Uwe; Jemian, Pete R.; Männicke, David; Osborn, Raymond; Peterson, Peter F.; Richter, Tobias; Suzuki, Jiro; Watts, Benjamin; Wintersberger, Eugen; Wuttke, Joachim

    2015-01-01

    NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitions for the exchange of data between applications. NeXus provides structures for raw experimental data as well as for processed data. PMID:26089752

  14. The NeXus data format

    SciTech Connect

    Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.; Brewster, Aaron S.; Campbell, Stuart I.; Clausen, Björn; Cottrell, Stephen; Hoffmann, Jens Uwe; Jemian, Pete R.; Männicke, David; Osborn, Raymond; Peterson, Peter F.; Richter, Tobias; Suzuki, Jiro; Watts, Benjamin; Wintersberger, Eugen; Wuttke, Joachim

    2015-01-30

    NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitions for the exchange of data between applications. NeXus provides structures for raw experimental data as well as for processed data.

  15. The NeXus data format

    DOE PAGES

    Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.; ...

    2015-01-30

    NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitionsmore » for the exchange of data between applications. NeXus provides structures for raw experimental data as well as for processed data.« less

  16. Web life: Mahalo.ne.Trash

    NASA Astrophysics Data System (ADS)

    2014-05-01

    Mahalo.ne.Trash is the personal blog of John Asher Johnson, an astronomer at Harvard University in the US who began blogging in 2007, when he was about to begin a postdoctoral fellowship at the University of Hawaii.

  17. MicroBooNE Detector Move

    ScienceCinema

    Flemming, Bonnie; Rameika, Gina

    2016-07-12

    On Monday, June 23, 2014 the MicroBooNE detector -- a 30-ton vessel that will be used to study ghostly particles called neutrinos -- was transported three miles across the Fermilab site and gently lowered into the laboratory's Liquid-Argon Test Facility. This video documents that move, some taken with time-lapse camerad, and shows the process of getting the MicroBooNE detector to its new home.

  18. MicroBooNE Detector Move

    SciTech Connect

    Flemming, Bonnie; Rameika, Gina

    2014-06-25

    On Monday, June 23, 2014 the MicroBooNE detector -- a 30-ton vessel that will be used to study ghostly particles called neutrinos -- was transported three miles across the Fermilab site and gently lowered into the laboratory's Liquid-Argon Test Facility. This video documents that move, some taken with time-lapse camerad, and shows the process of getting the MicroBooNE detector to its new home.

  19. [Antimicrobial activity of Actinomycetale isolated from the lagoon in Algeria].

    PubMed

    Alliouch-Kerboua, Chérifa; Gacemi Kirane, Djamila; La Scola, Bernard

    2015-01-01

    In the aim of the study of the taxonomy and the antimicrobial activity, a strain of actinomycete SM2/2GF which was isolated from sediment of the lagoon El-Mellah which is situated in the city of El-Kala in the Northeast of Algeria, was tested against diverse pathogenic microorganisms and against a Gram-negative bacterium Pseudomonas alcaliphila which was isolated from water of the lagoon El-Mellah. The phenotypic and the molecular characteristics show that the isolate SM2/2GF belongs to the kind Streptomyces. This strain showed an antimicrobial activity against a Gram-negative bacterium Pseudomonas alcaliphila and the positive-Gram bacteria as Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Bacillus subtilis, Enterococcus faecalis, as well as the yeast Candida albicans. It has no activity against Pseudomonas aeruginosa. The interesting antimicrobial activity of the strain SM2/2GF against the pathogenic microorganisms could encourage further researches on one or several bioactive molecules which it secretes.

  20. Temporal changes of a macrobenthic assemblage in harsh lagoon sediments

    NASA Astrophysics Data System (ADS)

    Como, Serena; Magni, Paolo

    2009-08-01

    An opportunistic macrobenthic assemblage was studied from 2001 to 2003 in a central area of the Cabras lagoon (western Sardinia, Italy), known to be affected by environmental disturbances (i.e. organic over-enrichment of sediments, and episodic events of hypoxia/anoxia and sulphide development). We identified recurrent seasonal changes in this macrobenthic assemblage, with a general impoverishment in summer and a recovery in winter/spring. The nereids Neanthes succinea and Hediste diversicolor were found to replace the spionid Polydora ciliata as the most dominant species in the summer for 3 consecutive years. Occasional, unsynchronized appearances of small-sized deposit feeders, such as Tubificidae, Capitella cf. capitata, chironomid larvae and Hydrobia spp., were observed in winter/spring. We suggest that these changes are driven by the interplay of environmental conditions (worse in summer) with numerous biotic factors. This includes different tolerance levels of taxa to low oxygen concentrations and sulphides, variability in larval supply and post-larval transport, as well as competition for space and food between and within different functional groups, and facilitation through animal bioturbation and sediment reoxidation. A conceptual model is proposed to demonstrate how environmental conditions and biotic interactions may control the benthic assemblage in such a harsh lagoon environment.

  1. Enteric viruses in a mangrove lagoon, survival and shellfish incidence

    SciTech Connect

    Lopez de Cardona, I.; Bermudez, M.; Billmire, E.; Hazen, T.C.

    1988-12-31

    Mangrove oysters (Crassostrea rhizophorae) were screened for enteric viruses. For 18 months oysters were collected from Cano Boqueron, a tropical mangrove lagoon on the southwest coast of Puerto Rico. This popular tourist resort has two primary sewage treatment plants which service 158 single family cabanas. In spite of the heavy seasonal input of sewage to Cano Boqueron and high densities of fecal coliform bacteria, enteric viruses were not detected in shellfish meat. Because no viruses were detected in the oysters, a virus survival study was performed. Poliovirus type 1 was placed in diffusion chambers in situ at two sites in Cano Boqueron. More than 95% of the poliovirus inactivation occurred within 24 h. Virus inactivation was significantly different by site, indicating different inactivation rates within the lagoon. Chamber studies done simultaneously with Escherichia coli did not reveal differences between sites. It is suggested that the sewage effluent had an antiviral effect in the absence of an antibacterial effect. This study demonstrates the importance for establishing microbial contamination standards for shellfish growing waters in the tropics based upon in situ studies with tropical species, e.g. mangrove oyster.

  2. Electromagnetic Transition Strengths in 27Ne

    NASA Astrophysics Data System (ADS)

    Loelius, Charles; Iwasaki, Hironori; Whitmore, Kenneth; Grinder, Mara; Elder, Robert; Lunderberg, Eric; Elman, Brandon; Longfellow, Brenden; Gade, Alexandra; Bazin, Daniel; Weisshaar, Dirk; Bender, Peter; Belarge, Joe; Kobayashi, Nobu; Petri, Marina; Heil, Sebastian; Mathy, Michael; Syndikus, Ina; Hufnagel, Alexander

    2016-09-01

    Previous measurements have established that halo nuclei are well characterized by their electromagnetic properties, with the E1 transition strengths reflecting a large neutron radius, and M1 transition strengths characterizing the dominant s wave strength. The 1/2+ excited state of 27Ne is close to the neutron separation energy and is expected to have a single valence neutron in the s orbital, and therefore has the potential to exhibit halo effects. Furthermore, neighboring isotopes 26Ne, 28Ne demonstrate substantial deformation, so that 27Ne should serve as an excellent benchmark for investigating the interplay between halo and deformation effects. We present here results of a new measurement of the lifetime of the 27Ne 1/2+ excited state, performed at the NSCL using the Recoil Distance Method with the TRIPLEX Plunger in conjunction with GRETINA. In addition, a Coulomb-excitation measurement of 27Ne has been performed using a novel application of the TRIPLEX plunger. The resulting transition strengths have been extracted and their implications are discussed.

  3. Excitation functions of the {sup 20}Ne+{sup 20}Ne system

    SciTech Connect

    Barrow, S.P.; Zurmuehle, R.; Murgatroyd, J.T.; Wimer, N.G.; Miao, Y.; Pohl, K.R.; Wuosmaa, A.H.; Betts, R.R.; Freer, M.; Glagola, B.

    1995-04-01

    A differentially pumped windowless {sup 20}Ne gas target and a {sup 20}Ne beam produced with the ATLAS accelerator at Argonne National Laboratory were used to measure angle-averaged excitation functions for binary decay of {sup 20}Ne+{sup 20}Ne into low-lying states of {sup 20}Ne+{sup 20}Ne and {sup 24}Mg+{sup 16}O, in the region of excitation energy in {sup 40}Ca from 51.4 to 58.2 MeV ({sup 20}Ne beam energies from 61.8 to 75.4 MeV). The {sup 20}Ne+{sup 20}Ne mass partition displays little correlated structure and there exists no evidence of intermediate width resonances in these channels with branching ratios comparable to those seen in the {sup 24}Mg+{sup 24}Mg system. Angular distributions for the elastic channel are consistent with those obtained using optical-model calculations. The exictation functions for the low-lying channels in {sup 24}Mg+{sup 16}O do contain some structures, with widths varying from 400 to 800 keV in the c.m. system.

  4. Sludge-Drying Lagoons: a Potential Significant Methane Source in Wastewater Treatment Plants.

    PubMed

    Pan, Yuting; Ye, Liu; van den Akker, Ben; Ganigué Pagès, Ramon; Musenze, Ronald S; Yuan, Zhiguo

    2016-02-02

    "Sludge-drying lagoons" are a preferred sludge treatment and drying method in tropical and subtropical areas due to the low construction and operational costs. However, this method may be a potential significant source of methane (CH4) because some of the organic matter would be microbially metabolized under anaerobic conditions in the lagoon. The quantification of CH4 emissions from lagoons is difficult due to the expected temporal and spatial variations over a lagoon maturing cycle of several years. Sporadic ebullition of CH4, which cannot be easily quantified by conventional methods such as floating hoods, is also expected. In this study, a novel method based on mass balances was developed to estimate the CH4 emissions and was applied to a full-scale sludge-drying lagoon over a three year operational cycle. The results revealed that processes in a sludge-drying lagoon would emit 6.5 kg CO2-e per megaliter of treated sewage. This would represent a quarter to two-thirds of the overall greenhouse gas (GHG) emissions from wastewater-treatment plants (WWTPs). This work highlights the fact that sludge-drying lagoons are a significant source of CH4 that adds substantially to the overall GHG footprint of WWTPs despite being recognized as a cheap and energy-efficient means of drying sludge.

  5. Use of deep water lagoons for reducing sewage toxicity prior to wastewater treatment

    SciTech Connect

    Shaw, J.R.; Zuiderveen, J.A.; Belcher, B.; McGinley, P.; Birge, W.J.

    1994-12-31

    Investigations were conducted to determine the effectiveness of deep lagoons as a means of wastewater pretreatment. A lagoon system associated with a wastewater treatment plant (WWTP) was selected for study and parameters identified for monitoring included toxicity, metals, total suspended solids (TSS) and ammonia. This system included two lagoons, with 7--15 day hydraulic retention times, fed sequentially with untreated water. Toxicity and other parameters were measured for raw influent water, the two lagoon outfalls, and the final WWTP effluent. In seven-day chronic tests with Ceriodaphnia dubia, the NOEC of influent water was as low as 20%, and 100% mortality occurred at 40%. Outfall from the first deep water lagoon showed reduced toxicity. The NOEC was > 50% but complete mortality occurred in undiluted effluent. Further reduction in toxicity occurred in the second lagoon. Its undiluted effluent had no effect on survival, but did markedly reduce fecundity. The final effluent discharged from the treatment plant affected neither survival nor fecundity. Results of this investigation support the use of deep water lagoons as an effective and economical means of pretreating wastewater. This approach offers promise for municipal waters, industrial effluents and stormwater runoff.

  6. A comparative study of the pollution status of Sakumo II and Muni lagoons in Ghana.

    PubMed

    Tay, Collins; Asmah, Ruby; Biney, Charles A

    2010-01-01

    The pollution status of Sakumo II and Muni Lagoons and Mamahuma and Gbagbla Ankonu feeder streams, which feed Sakumo II along the coast of Ghana, were assessed and compared. As expected of saline waters, pH values of both lagoons fell within a slightly neutral to saline range whilst, the feeder streams were moderately saline. Conductivity distribution also showed saline (>5.0 mS cm(-1)) characteristics of the lagoons, while, the feeder streams are brackish (1.5-5.0 mS cm(-1)). DO concentrations in both lagoons indicated a wide variation. Relatively high BOD and nutrients content of Sakumo II and the feeder streams suggested that, Sakumo II and its feeder streams are moderately to grossly polluted. However, Muni Lagoon was characterized by relatively low BOD and nutrients content suggesting relatively low anthropogenic impact. The ionic dominance patterns for Sakumo II and Muni Lagoons were: Na(+) > Mg(2 + ) > Ca(2 + ) and Cl(-) > HCO(3)(-) > SO(4)(2-), Na(+) > Ca(2 + ) > Mg(2 + ) and Cl(-) > HCO(3)(-) > SO(4)(2-), respectively. Using water quality index (WQI), Sakumo II was found to be grossly polluted and requires mitigation measures, while, Muni Lagoon was of fairly good quality and requires monitoring.

  7. A Bayesian network model for assessing natural estrogen fate and transport in a swine waste lagoon.

    PubMed

    Lee, Boknam; Kullman, Seth W; Yost, Erin; Meyer, Michael T; Worley-Davis, Lynn; Williams, C Michael; Reckhow, Kenneth H

    2014-10-01

    Commercial swine waste lagoons are regarded as a major reservoir of natural estrogens, which have the potential to produce adverse physiological effects on exposed aquatic organisms and wildlife. However, there remains limited understanding of the complex mechanisms of physical, chemical, and biological processes that govern the fate and transport of natural estrogens within an anaerobic swine lagoon. To improve lagoon management and ultimately help control the offsite transport of these compounds from swine operations, a probabilistic Bayesian network model was developed to assess natural estrogen fate and budget and then compared against data collected from a commercial swine field site. In general, the model was able to describe the estrogen fate and budget in both the slurry and sludge stores within the swine lagoon. Sensitivity analysis within the model demonstrated that the estrogen input loading from the associated barn facility was the most important factor in controlling estrogen concentrations within the lagoon slurry storage, whereas the settling rate was the most significant factor in the lagoon sludge storage. The degradation reactions were shown to be minor in both stores based on prediction of average total estrogen concentrations. Management scenario evaluations demonstrated that the best possible management options to reduce estrogen levels in the lagoon are either to adjust the estrogen input loading from swine barn facilities or to effectively enhance estrogen bonding with suspended solids through the use of organic polymers or inorganic coagulants.

  8. Genesis, distribution, and dynamics of lagoon marl extrusions along the Curonian Spit, southeast Baltic Coast

    NASA Astrophysics Data System (ADS)

    Sergeev, Alexander; Zhamoida, Vladimir; Ryabchuk, Daria; Buynevich, Ilya; Sivkov, Vadim; Dorokhov, Dmitry; Bitinas, Albertas; Pupienis, Donatas

    2016-04-01

    The unique geological process of extrusion of lagoon marl from beneath the massive migrating sand dunes is characteristic for large segments of the Curonian Spit - a ~100-km-long sandy barrier that separates the Curonian Lagoon from the Baltic Sea. The exposures of a composite set of Holocene organic sediments such as gyttja, clayey gyttja, and gyttja clay, commonly referred to as "lagoon marl", are common along the northern half of the lagoon coast of the spit. These outcrops of lagoon marl rise up to 3-4 m above the lagoon level and were formed by extrusion from their 7-8 m in situ depth beneath the present regional water table. New detailed investigations of the Baltic Sea bottom along the southern half of the Curonian Spit using side-scan sonar, multibeam echosounder, seismic imaging, sediment sampling, and video observations allowed identification and mapping of a unique underwater landscape formed by extensive outcrops of laminated and folded lagoon marl at water depths of 5-15 m. The combined onshore-offshore database indicates that the relict lagoon marl was deformed, compacted, and dehydrated by a massive dune-covered coastal barrier migrating landward (retrograding) over these sediments during the Litorina Sea transgression in a processes termed "dune tectonics". Spatial analysis of structures of the relict sediments traced in offshore geophysical data help constrain the rates of the southeastly migration of the dune massif. A conceptual dynamic model is presented to explain the present occurrence of marl exposures above the regional water table, as well as the occurrence of relict lagoon marl extrusions (diapirs) on the underwater marine slope of the Curonian Spit. This research was funded by a RFBR project 13-05-90711 and RSF project 14-37-00047 «Geoenvironmental conditions of marine management of natural recourses of the Russian sector of South-Eastern Baltic».

  9. Use of deep water lagoons for reducing sewage toxicity prior to wastewater treatment

    SciTech Connect

    Shaw, J.R.; Zuiderveen, J.A.; Belcher, B.; McGinley, P.; Birge, W.J.

    1995-12-31

    Investigations were conducted to determine the effectiveness of deep lagoons as a means of minimizing toxicity and reducing wastewater parameters. A lagoon system associated with a wastewater treatment plant (WWTP) was selected for study and parameters identified for monitoring included toxicity, metal concentrations, total suspended solids (TSS) and ammonia. This system included two lagoons, with 7--15 day hydraulic retention times, which received municipal waste. Toxicity and other parameters were measured for raw influent water, the two lagoon outfalls, and the final WWTP effluent. In a definitive seven-day chronic test with Ceriodaphnia dubia, the NOEC of influent water was 20%, and the IC{sub 50} for reproduction was 22.3%. Outfall from the first deep water lagoon showed reduced toxicity. The NOEC and IC{sub 50} were 80 and 71.8%, respectively. Further reduction in toxicity occurred in the second lagoon. The NOEC was 80% and the IC{sub 50} was 75.9. The final effluent discharged from the treatment plant affected neither survival nor fecundity. A 7-day embryo larval test conducted with Pimephales promelas yielded similar results. NOEC values increased through the lagoon system and were 2.5, 40.0, 40.0 and 100%, respectively. Acute TIE procedures implicated both metals and ammonia as primary toxicants. In all tests a sequential reduction in toxicity was observed through the lagoons. Results of this investigation support the use of deep water lagoons as an effective and economical means of pretreating wastewater. This approach offers promise for municipal waters, industrial effluents and stormwater runoff.

  10. Comparative study based on sediment characteristics and macrobenthic communities in two Italian lagoons.

    PubMed

    Specchiulli, Antonietta; Renzi, Monia; Scirocco, Tommaso; Cilenti, Lucrezia; Florio, Marisa; Breber, Paolo; Focardi, Silvia; Bastianoni, Simone

    2010-01-01

    The aims of this study were to analyse sediment characteristics and macrobenthic assemblages in two very close Italian coastal lagoons (Lesina and Varano) and to assess the different behaviour between the two basins and the relationship between sediment matrix and benthic organisms within and between the two lagoons. The comparative study was performed in July 2007 at 13 sampling sites in Lesina lagoon and 15 sites in Varano basin for sediment grain size, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP) and macrobenthic structure analyses. Both lagoons were generally dominated by fine-grained sediments (clay and silt components). The average contents of TOC and TN measured in Lesina was higher than in Varano (3.31% vs 2.52% for TOC and 5,200 microg.g(-1) vs 3,713 microg.g(-1) for TN); in contrast, the TP was lower (540 microg.g(-1) vs 620 microg.g(-1)). Based on macrobenthic community patterns, the central zone in Varano lagoon and the eastern area in Lesina lagoon were characterised by the lowest abundance (168.7 ind.m(-2) and 503.2 ind.m(-2), respectively) and by the lowest number of species, as highlighted by the diversity indices (Shannon-Wiener, H' range was 0.47-1.45 for Lesina and 0.00-1.68 for Varano; Margalef species richness, d range was 0.00-1.67 for Lesina lagoon and 0.00-2.38 for Varano basin). Ordination diagrams suggested an influence of marine and freshwater inputs on the sediment distribution in Varano lagoon and on macrobenthic assemblages in Lesina lagoon.

  11. Regime shifts in coastal lagoons: Evidence from free-living marine nematodes.

    PubMed

    Netto, Sergio A; Fonseca, Gustavo

    2017-01-01

    We test the validity of using the regime shift theory to account for differences in environmental state of coastal lagoons as a response to variation in connectivity with the sea, using free-living nematodes as a surrogate. The study is based on sediment samples from the inner and outer portions of 15 coastal lagoons (5 open to the sea, 5 intermittently open/closed, and 5 permanently closed lakes) along the southern coast of Brazil. Environmental data suggested that there are two contrasting environmental conditions, with coastal lakes being significantly different from open and intermittent lagoons. Marine nematode assemblages corroborate these two mutually exclusive alternative stable states (open vs. closed systems), but assemblages from the intermittently open/closed lagoons showed a gradual change in species composition between both systems independently of the environmental conditions. The gradient in the structural connectivity among lagoons and the sea, due to their regime shifts, changes the movement of resources and consumers and the internal physico-chemical gradients, directly affecting regional species diversity. Whereas openness to the sea increased similarity in nematode assemblage composition among connected lagoons, isolation increased dissimilarity among closed lagoons. Our results from a large-scale sampling program indicated that as lagoons lose connectivity with the sea, shifting the environmental state, local processes within individual intermittently open/closed lagoons and particularly within coastal lakes become increasingly more important in structuring these communities. The main implication of these findings is that depending on the local stable state we may end up with alternative regional patterns of biodiversity.

  12. Regime shifts in coastal lagoons: Evidence from free-living marine nematodes

    PubMed Central

    2017-01-01

    We test the validity of using the regime shift theory to account for differences in environmental state of coastal lagoons as a response to variation in connectivity with the sea, using free-living nematodes as a surrogate. The study is based on sediment samples from the inner and outer portions of 15 coastal lagoons (5 open to the sea, 5 intermittently open/closed, and 5 permanently closed lakes) along the southern coast of Brazil. Environmental data suggested that there are two contrasting environmental conditions, with coastal lakes being significantly different from open and intermittent lagoons. Marine nematode assemblages corroborate these two mutually exclusive alternative stable states (open vs. closed systems), but assemblages from the intermittently open/closed lagoons showed a gradual change in species composition between both systems independently of the environmental conditions. The gradient in the structural connectivity among lagoons and the sea, due to their regime shifts, changes the movement of resources and consumers and the internal physico-chemical gradients, directly affecting regional species diversity. Whereas openness to the sea increased similarity in nematode assemblage composition among connected lagoons, isolation increased dissimilarity among closed lagoons. Our results from a large-scale sampling program indicated that as lagoons lose connectivity with the sea, shifting the environmental state, local processes within individual intermittently open/closed lagoons and particularly within coastal lakes become increasingly more important in structuring these communities. The main implication of these findings is that depending on the local stable state we may end up with alternative regional patterns of biodiversity. PMID:28235030

  13. Toxic metals in Venics lagoon sediments: Model, observation, an possible removal

    SciTech Connect

    Basu, A.; Molinaroli, E.

    1994-11-01

    We have modeled the distribution of nine toxic metals in the surface sediments from 163 stations in the Venice lagoon using published data. Three entrances from the Adriatic Sea control the circulation in the lagoon and divide it into three basins. We assume, for purposes of modeling, that Porto Marghera at the head of the Industrial Zone area is the single source of toxic metals in the Venice lagoon. In a standing body of lagoon water, concentration of pollutants at distance x from the source (C{sub 0}) may be given by C=C{sub 0}e{sup -kx} where k is the rate constant of dispersal. We calculated k empirically using concentrations at the source, and those farthest from it, that is the end points of the lagoon. Average k values (ppm/km) in the lagoon are: Zn 0.165, Cd 0.116, Hg 0.110, Cu 0.105, Co 0.072, Pb 0.058, Ni 0.008, Cr (0.011) and Fe (0.018 percent/km), and they have complex distributions. Given the k values, concentration at source (C{sub 0}), and the distance x of any point in the lagoon from the source, we have calculated the model concentrations of the nine metals at each sampling station. Tides, currents, floor morphology, additional sources, and continued dumping perturb model distributions causing anomalies (observed minus model concentrations). Positive anomalies are found near the source, where continued dumping perturbs initial boundary conditions, and in areas of sluggish circulation. Negative anomalies are found in areas with strong currents that may flush sediments out of the lagoon. We have thus identified areas in the lagoon where higher rate of sediment removal and exchange may lesson pollution. 41 refs., 4 figs., 3 tabs.

  14. Trophic structure and functioning in a eutrophic and poorly flushed lagoon in southwestern Taiwan.

    PubMed

    Lin, Hsing-Juh; Dai, Xiao-Xun; Shao, Kwang-Tsao; Su, Huei-Meei; Lo, Wen-Tseng; Hsieh, Hwey-Lian; Fang, Lee-Shing; Hung, Jia-Jang

    2006-07-01

    Tapong Bay, a eutrophic and poorly flushed tropical lagoon, supports intensive oyster culture. Using the Ecopath approach and network analysis, a mass-balanced trophic model was constructed to analyze the structure and matter flows within the food web. The lagoon model is comprised of 18 compartments with the highest trophic level of 3.2 for piscivorous fish. The high pedigree index (0.82) reveals the model to be of high quality. The most-prominent living compartment in terms of matter flow and biomass in the lagoon is cultured oysters and bivalves, respectively. The mixed trophic impacts indicate that phytoplankton and periphyton are the most-influential living compartments in the lagoon. Comparative analyses with the eutrophic and well-flushed Chiku Lagoon and non-eutrophic tropical lagoons show that high nutrient loadings might stimulate the growth and accumulation of phytoplankton and periphyton and therefore support high fishery yields. However, net primary production, total biomass, fishery yields per unit area, and mean transfer efficiency of Tapong Bay were remarkably lower than those of Chiku Lagoon. The lower transfer efficiency likely results from the low mortality of cultured oysters and invasive bivalves from predation or the lower density of benthic feeders constrained by the hypoxic bottom water as a result of poor flushing. This might therefore result in a great proportion of flows to detritus. However, the hypoxic bottom water might further reduce the recycling of the entering detritus back into the food web. In contrast to many estuaries and tropical lagoons, poor flushing of this eutrophic tropical lagoon might induce a shift from detritivory to herbivory in the food web.

  15. Lacaziosis in bottlenose dolphins (Tursiops truncatus) in the Indian River Lagoon, Florida, USA.

    PubMed

    Durden, Wendy Noke; St Leger, Judy; Stolen, Megan; Mazza, Teresa; Londono, Catalina

    2009-07-01

    The objective of this study was to document the presence of the fungal granulomatous skin disease lacaziosis in stranded Indian River Lagoon (IRL) bottlenose dolphins (Tursiops truncatus). From 1 January 2007 through 31 December 2007, stranded dolphins from the northern part of the IRL were thoroughly examined, and appropriate tissue samples were collected. The intralesional fungal agent (Lacazia loboi) was identified histologically in three bottlenose dolphins. Histologically, lacaziosis has been previously documented in IRL dolphins inhabiting the southern portion of the lagoon. Our findings suggest that the disease occurs throughout the lagoon. Enhanced monitoring of the prevalence of lacaziosis in dolphins throughout the IRL is needed to assess changes in population health.

  16. Lagoon microbialites on Isla Angel de la Guarda and associated peninsular shores, Gulf of California (Mexico)

    NASA Astrophysics Data System (ADS)

    Johnson, Markes E.; Ledesma-Vázquez, Jorge; Backus, David H.; González, Maria R.

    2012-07-01

    Examples of two closed lagoons with extensive growth of Recent microbialites showing variable surface morphology and internal structure are found on Isla Angel de la Guarda in the Gulf of California. Comparable lagoonal microbialites also occur ashore from Ensenada El Quemado on the adjacent peninsular mainland of Baja California. The perimeters of all three lagoons feature crusted structures indicative of thrombolites with a knobby surface morphology 2 cm to 3 cm in relief and internal clotting without any sign of laminations. Outward from this zone, thrombolitic construction thins to merge with a white calcified crust below which a soft substratum of dark organic material 4 cm to 6 cm in thickness is concealed. The substratum is laminated and heavily mucilaginous, as observed along the edges of extensive shrinkage cracks in the overlying crust. The thrombolitic crust is anchored to the shore, while the thinner crust and associated stromatolitic mats float on the surface of the lagoons. Laboratory cultures of the dark organic material yielded the solitary cyanobacterium Chroococcidiopsis as the predominant taxon interspersed with filamentous forms. In decreasing order of abundance, other morphotypes present include Phormidium, Oscillatoria, Geitlerinema, Chroococus, and probably Spirulina. The larger of the two island lagoons follows an east-west azimuth and covers 0.225 km2, while the smaller lagoon has a roughly north-south axis and covers only 0.023 km2. The salinity of water in the smaller lagoon was measured as148 ppt. Pliocene strata along the edge of the smaller modern lagoon include siltstone bearing calcified platelets suggestive of a microbial origin. Dry lagoons abandoned during the later Quaternary occur inland at higher elevations on the island, but retain no fossils except for sporadic white crusts cemented on cobbles around distinct margins. Raised Quaternary lagoons parallel to the big lagoon on Isla Angel de la Guarda are partly obscured by flood

  17. Ship traffic and shoreline erosion in the Lagoon of Venice

    NASA Astrophysics Data System (ADS)

    Scarpa, Gian Marco; Zaggia, Luca; Lorenzetti, Giuliano; Manfè, Giorgia; Parnell, Kevin; Molinaroli, Emanuela; Rapaglia, John; Gionta, Sofia

    2016-04-01

    A study based on the analysis of a historical sequence of aerial photographs and satellite images combined with in situ measurements revealed an unprecedented shoreline regression on the side of a major waterway in the Venice Lagoon, Italy. The study considered long and short-term recession rates caused by ship-induced depression wakes in an area which was reclaimed at the end of the '60 for the expansion of the nearby Porto Marghera Industrial Zone and never used since then. The GIS analysis performed with the available imagery shows an average retreat of about 4 m yr-1 in the period between 1965 and 2015. Field measurements carried out between April 2014 and January 2015 also revealed that the shoreline's regression still proceed with a speed comparable to the long-term average regardless of the distance from the navigation channel and is not constant through time. Periods of high water levels determined by astronomical tide or storm surges, more common in the winter season, are characterized by faster regression rates. The retreat proceeds by collapse of slabs of the reclaimed muddy soil after erosion and removal of the underlying original salt marsh sediments and is a discontinuous process in time and space depending on morphology, intrinsic propertiesand vegetation cover of the artificial deposits. Digitalization of historical maps and new bathymetric surveys made in April 2015 allowed for the reconstruction of two digital terrain models for both past and present situations. The two models have been used to calculate the total volume of sediment lost during the period between 1970 and 2015. The results of this study shows as ship-channel interactions can dominate the morphodynamics of a waterway and its margins and permitted to better understand how this part of the Venice Lagoon reacted to the pressure of human activities in the post-industrial period. Evaluation of the temporal and spatial variation of shoreline position is also crucial to predict future

  18. Cross section analyses in MiniBooNE and SciBooNE experiments

    SciTech Connect

    Katori, Teppei

    2015-05-15

    The MiniBooNE experiment (2002-2012) and the SciBooNE experiment (2007-2008) are modern high statistics neutrino experiments, and they developed many new ideas in neutrino cross section analyses. In this note, I discuss selected topics of these analyses.

  19. X-616 Chromium Sludge Lagoons pictorial overview, Piketon, Ohio

    SciTech Connect

    Not Available

    1992-10-01

    The Portsmouth Gaseous Diffusion Plant uses large quantities of water for process cooling. The X-616 Liquid Effluent Control Facility was placed in operation in December 1976 to treat recirculation cooling water blowdown from the process cooling system. A chromium-based corrosion inhibitor was used in the cooling water system. A chromium sludge was produced in a clarifier to control chromium levels in the water. Chromium sludge produced by this process was stored in two surface impoundments called the X-616 Chromium Sludge Lagoons. The sludge was toxic due to its chromium concentration and therefore required treatment. The sludge was treated, turning it into a sanitary waste, and buried in an Ohio EPA approved landfill. The plant's process cooling water system has changed to a more environmentally acceptable phosphate-based inhibitor. Closure activities at X-616 began in August 1990, with all construction activities completed in June 1991, at a total cost of $8.0 million.

  20. Biotin Production and Utilization in a Sewage Treatment Lagoon 1

    PubMed Central

    Fillipi, Gordon M.; Vennes, John W.

    1971-01-01

    Biotin, in a sewage oxidation lagoon also receiving potato processing wastes, was observed to increase two logs during the summer period of waste stabilization and then to decline to near earlier concentrations. Three organisms, Aerobacter aerogenes, Chlorella vulgaris, and Thiocapsa floridana, were at least partially responsible for these fluctuations; the latter two organisms were associated with biotin utilization and the former with biotin production. Since copious quantities of biotin are produced in these waste treatment facilities, the vitamin may act as a useful indicator of microbial action on certain organic molecules, especially in domestic and industrial wastes such as those from municipalities and potato and sugar beet processing plants. Furthermore, the presence of biotin in rivers and streams may be indicative of the discharge of incompletely stabilized wastes from these sources. PMID:4939123

  1. Wind Induced Resuspension in a Shallow Tropical Lagoon

    NASA Astrophysics Data System (ADS)

    Arfi, R.; Guiral, D.; Bouvy, M.

    1993-06-01

    In shallow environments, particle resuspension can induce large ecological effects. Under some certain conditions of fetch, wind velocity, bathymetry and bed roughness, resuspension is generated by wind induced waves. During December 1991, a shallow station (1 m depth) in the north shore of a tropical lagoon (Côte d'Ivoire) was investigated in order to study the impact of wind induced resuspension on the ecosystem. In this area, Austral Trade winds are dominant almost all year long, and their velocity shows a marked diel pattern. During the survey, three sequences were distinguished: a period of Austral Trade winds (with possible resuspension), a period of Boreal Trade winds (no wind induced waves at the station) and a period of transitional Trade winds. Only Austral Trade winds with a speed >3 m s -1 allowed particle resuspension. For chlorophyll, mineral seston and ammonia, significantly higher values were noted during the windy sequences. Conductivity and water colour varied in relation to tides. Granulometric and mineralogical analyses showed that only the 0-3 cm superficial level of the sediment was involved in resuspension. This process induced several effects: (1) an increase of suspended matter concentration in the water and thus a light attenuation due to a higher turbidity, (2) a distribution in the whole water column of nutrients from the pore water, (3) a modification of the sediment granulometric characteristics and (4) an increase in the food available for planktonic filter feeders since algal cells were periodically resuspended in the whole water column. Wind induced resuspension occurred in 10% of the Ebrié lagoon. In this area, the daily alternate of resuspension-sedimentation sequence is then a major factor controlling the productivity of a system which is potentially highly productive (high nutrient load, favourable climatic conditions) yet characterized by high turbidity. These observations can be generalized to comparable systems in the

  2. Biological control of trace metal and organometal benthic fluxes in a eutrophic lagoon (Thau Lagoon, Mediterranean Sea, France)

    NASA Astrophysics Data System (ADS)

    Point, D.; Monperrus, M.; Tessier, E.; Amouroux, D.; Chauvaud, L.; Thouzeau, G.; Jean, F.; Amice, E.; Grall, J.; Leynaert, A.; Clavier, J.; Donard, O. F. X.

    2007-04-01

    In situ benthic chamber experiments were conducted in the Thau Lagoon that allowed the simultaneous determination of the benthic exchanges of trace metals (Cd, Co, Cu, Mn, Pb and U) and mercury species (iHg and MMHg). Fluxes of organotin compounds (MBT, DBT and TBT) were also investigated for the first time. The benthic incubations were performed during two campaigns at four stations that presented different macrobenthic and macrophytic species distribution and abundance (see [Thouzeau, G., Grall, J., Clavier, J., Chauvaud, L., Jean, F., Leynaert, A., Longpuirt, S., Amice, E., Amouroux, D., 2007. Spatial and temporal variability of benthic biogeochemical fluxes associated with macrophytic and macrofaunal distributions in the Thau lagoon (France). Estuarine, Coastal and Shelf Science 72 (3), 432 446.]). The results indicate that most of the flux intensity as well as the temporal and spatial variability can be explained by the combined influence of microscale and macroscale processes. Microscale changes were identified using Mn flux as a good indicator of the redox conditions at the sediment water interface, and by extension, as an accurate proxy of benthic fluxes for most trace metals and mercury species. We also observed that the redox gradient at the interface is promoted by both microbial and macrobenthic species activity that governs O2 budgets. Macroscale processes have been investigated considering macrobenthic organisms activity (macrofauna and macroalgal cover). The density of such macroorganisms is able to explain most of the spatial and temporal variability of the benthic metal fluxes within a specific site. A tentative estimation of the flux of metals and organometals associated with deposit feeder and suspension feeder activity was found to be in the range of the flux determined within the chambers for most considered elements. Furthermore, a light/dark incubation investigating a dense macroalgal cover present at the sediment surface illustrates the role

  3. ANALYSIS OF LAGOON SAMPLES FROM DIFFERENT CONCENTRATED ANIMAL FEEDING OPERATIONS FOR ESTROGENS AND ESTROGEN CONJUGATES

    EPA Science Inventory

    Although Concentrated Animal Feeding Operations CAFOs) have been identified as potentially important sources for the release of estrogens into the environment, information is lacking on the concentrations of estrogens in whole lagoon effluents (including suspended solids)which ar...

  4. Taxonomic diversity and structure of the molluscan fauna in Oualidia lagoon (Moroccan Atlantic coast).

    PubMed

    El Asri, F; Zidane, H; Maanan, M; Tamsouri, M; Errhif, A

    2015-08-01

    The spatial distribution of the molluscan fauna of Oualidia lagoon (Moroccan Atlantic coast) was studied during winter 2013. Samples were collected from 43 stations over the whole of the lagoon. Twenty-eight taxa (19 species of gastropods, 7 species of bivalves, 1 species of polyplacophora, and 1 species of cephalopod) were listed, 21 of which are newly reported for Oualidia lagoon. Four taxa, Hydrobia sp. (78.29%), followed by Abra alba (13.99 ), Nassarius pfeifferi (5.07%), and Cerastoderma edule (1.32%), were accounted for 98% of the total abundance. A classification analysis used to characterize the lagoon on the basis of molluscs showed the existence of three main clusters from downstream to upstream: a Nassarius pfeifferi community, a Hydrobia sp.-Abra alba community and a Hydrobia sp.-Cerastoderma edule community.

  5. Pearl oysters Pinctada margaritifera grazing on natural plankton in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia).

    PubMed

    Fournier, Jonathan; Dupuy, Christine; Bouvy, Marc; Couraudon-Réale, Marine; Charpy, Loïc; Pouvreau, Stephane; Le Moullac, Gilles; Le Pennec, Marcel; Cochard, Jean-Claude

    2012-01-01

    In atoll lagoons of French Polynesia, growth and reproduction of pearl oysters are mainly driven by plankton concentration. However, the actual diet of black-lip pearl oysters Pinctada margaritifera in these lagoons is poorly known. To fill this gap, we used the flow through chamber method to measure clearance rates of P. margaritifera in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia). We found: (i) that pearl oysters cleared plankton at a rate that was positively related to plankton biovolume, (ii) that nanoflagellates were the main source of carbon for the pearl oysters, and (iii) that the quantity and origin of carbon filtrated by pearl oysters was highly dependent on the concentration and composition of plankton. These results provide essential elements for the comprehension of growth and reproduction variability of pearl oysters in atoll lagoons of French Polynesia.

  6. Molecular Characterization of Swine Manure Lagoon Microbial and Antibiotic Resistant Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The differences in swine manure lagoon effluent based on differing management styles or approaches such as different stages of swine rearing determines the presence of variable antibiotic resistance determinants and functional microbial populations. These concerns determine the suitabil...

  7. Restriction of sponges to an atoll lagoon as a result of reduced environmental quality.

    PubMed

    Knapp, Ingrid S S; Williams, Gareth J; Carballo, José Luis; Cruz-Barraza, José Antonio; Gardner, Jonathan P A; Bell, James J

    2013-01-15

    The lagoon at Palmyra Atoll in the central Pacific was subject to major military modifications during WWII and now the dominant fauna on the lagoon's hard substrate are sponges, not corals. In this study, we quantified the physical and biological factors explaining the variation in sponge distribution patterns across 11 sites to determine the potential for the sponges in the lagoon at Palmyra to invade the surrounding reef systems. Significant differences in sponge assemblages were found among all but three sites. For all the models we examined the strongest environmental relationships were found for variables related to sedimentation/turbidity and food/habitat availability. Our findings suggest that the sponges in Palmyra's lagoon are likely to be restricted to this habitat type where they are associated with conditions resulting from the earlier heavy disturbance and are unlikely to spread to the outer reef environments unless there is a dramatic decline in environmental quality.

  8. The contribution of benthic macrofauna to the nutrient filter in coastal lagoons.

    PubMed

    Lloret, Javier; Marín, Arnaldo

    2011-12-01

    Human activities in coastal areas have increased the occurrence of eutrophication events, especially in vulnerable ecosystems such as coastal lagoons. Although we have a general knowledge of the consequences of eutrophication in these ecosystems, some efforts need to be made to understand biotic feedbacks that could modify the response of the environment to nutrient enrichment. The plant-mediated 'coastal filter' is one of the main factors that determine lagoonal efficiency in processing excess nutrients. In this context, the present paper examined the relative contribution of benthic macrofauna to the 'coastal filter' of a Mediterranean lagoon. The analysis of macrofaunal assemblages in the Mar Menor lagoon led to a clear differentiation between shallow areas of net nutrient recycling and exportation and deeper areas of net retention. These differences enhance nutrient removal from the water column, thus increasing the ecosystem's resistance to eutrophication.

  9. Exchange processes across sandy beach barriers: Examples from Malibu and Younger Lagoons, California

    NASA Astrophysics Data System (ADS)

    Swarzenski, P. W.; Dimova, N. T.; Izbicki, J. A.

    2010-12-01

    Estuarine systems in California can manifest themselves as shallow lagoons that are seasonally closed to the ocean by wave-built sand barriers. When a lagoon is physically isolated from the ocean, restricted circulation and sustained material inputs may cause eutrophication, low-oxygen conditions, and persistent algal blooms. During such times, the flow of water and material to the ocean must occur through a beach barrier rather than as surface-water runoff. This subsurface exchange can be modulated by the tides and expressed as a form of submarine groundwater discharge, SGD. Biogeochemically, this transport mode is much different than when a lagoon can exchange freely with the ocean, as redox conditions, organic matter concentrations, water residence times, and salinity can change dramatically. The objectives of this study were to: 1) characterize the seasonal patterns of SGD and associated nutrient loadings in two lagoonal systems that are intermittently isolated from the ocean; 2) assess the physical drivers of this exchange - can we identify the terrestrial versus marine forcing factors and what do these results imply for land / sea exchange along California’s coastline that has many such intermittent coastal systems? Two lagoons in California were studied: Younger Lagoon, an agriculturally-impacted coastal lagoon just north of Santa Cruz, and Malibu Lagoon located north of Los Angeles. Our observations during wet (October 2009 and April 2010) and dry conditions (July 2009) in Malibu captured both open- and closed-barrier scenarios. Lagoon water, groundwater, and seawater were analyzed for 222Rn, salinity, nutrients, DOC, and trace metals during all three field efforts. Initial data and calculations based on radon modeling indicate at least an order of magnitude larger groundwater flux to the lagoon during April 2010 (open barrier) as compared to July 2009, when the barrier was closed. A strong correlation (R2=0.85) between (NO2+NO3) concentrations in surface

  10. DAΦNE status and upgrade plans

    NASA Astrophysics Data System (ADS)

    Zobov, M.; DAΦNE Collaboration Team

    2008-12-01

    The Frascati Φ-factory DAΦNE has successfully completed experimental runs for the three main detectors, KLOE, FINUDA and DEAR. The best peak luminosity achieved so far is 1.6 × 1032 cm-2 s-1, while the best daily integrated luminosity is 10 pb-1. At present the DAΦNE team is preparing an upgrade of the collider based on the novel crab waist collision scheme. The upgrade is aimed at pushing the luminosity towards 1033cm-2s-1. In this paper we describe present collider performance and discuss ongoing preparatory work for the upgrade.

  11. An evaluation of the USEPA calculations of greenhouse gas emissions from anaerobic lagoons.

    PubMed

    Lory, John A; Massey, R E; Zulovich, J M

    2010-01-01

    On 10 Apr. 2009, USEPA proposed and on 30 Oct. 2009 USEPA finalized reporting thresholds for a wide range of human-derived sources of greenhouse gas (GHG) as a first step in establishing emission limits in the United States. The only on-farm source category that required monitoring under the proposed and final rule was methane (CH(4)) and nitrous oxide (NO(2)) emissions from manure storage facilities. Our objective was to assess, through a literature review, the methodology used by USEPA to estimate current CH(4) emissions from uncovered anaerobic lagoons and the proposed methodology for reporting those emissions under the proposed rule. A review of the performance of uncovered anaerobic lagoons indicates that they are more effective at degrading volatile solids (VS) than predicted using parameters provided by USEPA that had been developed for anaerobic digesters. We also documented errors in the USEPA- and International Panel on Climate Change-estimated methane conversion factors for uncovered anaerobic lagoons. We suggest estimating CH(4) emissions from anaerobic lagoons based on VS degraded in the lagoon and B' (m(3) CH(4) generated kg(-1) VS destroyed). Our estimate of CH(4) released from uncovered anaerobic lagoons indicated the regulatory operation size threshold could be at least 65% smaller than predicted by USEPA in the proposed rule. Our calculated estimate of CH(4) emissions was substantially greater than the few estimates of CH(4) loss based on direct measurements on uncovered anaerobic lagoons. More research is needed before it will be possible to provide definitive estimates of CH(4) loss from uncovered anaerobic lagoons.

  12. Quantification of water, salt and nutrient exchange processes at the mouth of a Mediterranean coastal lagoon.

    PubMed

    Sylaios, Georgios K; Tsihrintzis, Vassilios A; Akratos, Christos; Haralambidou, Kiriaki

    2006-08-01

    Vassova lagoon is a typical Mediterranean (small, shallow, micro-tidal, well-mixed) coastal lagoon, receiving limited seasonal freshwater inflows from direct precipitation and underground seepage. An intensive study was carried out in order to quantify the mechanisms responsible for the intra-tidal and residual transport of water, salt, nutrients and chlorophyll at the mouth of this lagoon and to assess the lagoon's flushing behavior. Results indicated that although the system is micro-tidal, tidal effects appeared to be the dominant factor for the longitudinal distribution of physical and chemical parameters, while the associated residual flow is also important and serves as a baseline measure of overall circulation. However, analysis of the net longitudinal currents and fluxes of water, salt and nutrients revealed the importance of non-tidal effects (wind effect and precipitation incidents) in the mean tidal transport. It is shown that the Eulerian residual currents transported water and its properties inwards under southern winds, while a seaward transport was induced during precipitation incidents and northern winds. The Stokes drift effect was found an order of magnitude lower than the Eulerian current, directed towards the lagoon, proving the partially-progressive nature of the tide. Nutrients and chlorophyll-alpha loads are exported from the lagoon to the open sea during the ebb phase of the autumn and winter tidal cycles, associated with the inflow of nutrient-rich freshwater, seeped through the surrounding drainage canal. The reverse transport occurs in spring and early summer, when nutrients enter the lagoon during the flood tidal phase, from the nutrient-rich upper layer of the stratified adjacent sea. Application of a tidal prism model shows that Vassova lagoon has a mean flushing time of 7.5 days, ranging between 4 to 18 days, affected inversely by the tidal oscillation.

  13. The Dynamics of Mercury Speciation and Transport at a Central California Coastal Lagoon

    NASA Astrophysics Data System (ADS)

    Ganguli, P. M.; Swarzenski, P. W.; Dimova, N. T.; Merckling, J.; Kehrlein, N. C.; Hohn, R. A.; Richardson, C. M.; Johnson, C. D.; Fisher, A. T.; Lamborg, C. H.; Flegal, A. R., Jr.

    2014-12-01

    We evaluated spatial and temporal trends in total mercury and monomethylmercury (MMHg) in groundwater, lagoon water, and nearshore seawater to assess the drivers of MMHg production in a coastal lagoon system. Many West Coast streams transition from estuarine to lagoon conditions in the dry season when a sand berm develops at the stream mouth, restricting surface water exchange with the ocean. Because lagoons accumulate nutrients from their upstream watershed they are susceptible to eutrophication, which can promote the growth of anaerobic bacteria. In nearshore settings, these bacteria are primarily responsible for producing MMHg, a bioaccumulative neurotoxin. We found that MMHg concentrations in lagoon water (1 - 5 pM) were higher than in groundwater (0.2 - 1 pM) and coastal seawater (0.1 - 0.6 pM). Groundwater depth profiles combined with subsurface resistivity images suggest MMHg in lagoon water was transported through the sand berm to adjacent seawater. MMHg in seawater and groundwater followed similar trends, providing additional evidence of groundwater-surface water interaction. MMHg in groundwater directly below the lagoon was consistently higher where dissolved oxygen and NO3- decreased, implying MMHg production by anaerobic bacteria. Over a ~7-hour period we observed a 0.6 pM decrease in groundwater MMHg (1 to 0.4 pM) that coincided with a decrease in water temperature (16.5 to 13 °C). We hypothesize that microbial activity, and consequently MMHg production, were enhanced in warmer water. Because coastal lagoons support intricate food webs and serve as nurseries for a variety of organisms, processes that influence mercury speciation and transport in these ecosystems may have a disproportionate impact on nearshore mercury biogeochemical cycling.

  14. Heavy metals in water, sediment and tissues of Liza saliens from Esmoriz-Paramos lagoon, Portugal.

    PubMed

    Fernandes, C; Fontaínhas-Fernandes, A; Cabral, D; Salgado, M A

    2008-01-01

    Esmoriz-Paramos lagoon is an ecosystem of great ecological importance that is located on the northwest coast of Portugal and has been degraded as a result of industrial and anthropogenic activities. Concentrations of heavy metals (Cr, Cu, Pb and Zn) were measured in water, sediment and in tissues (liver and muscle) of Liza saliens, which is the dominant fish from the lagoon. Comparisons between metal concentrations in water and sediments were made with those in tissues of fish caught at the lagoon. Metals in water were quantified predominantly bound to particulate and equalled or exceeded the limit of chronic reference values. Metal concentrations in sediments varied among sampled sites. The relative order of concentrations was "Zn > Cu approximately Pb > Cr" the same pattern observed for metals in water. Metals in fish tissues showed higher concentrations in liver (262 mg CuxKg(-1) and 89 mg ZnxKg(-1)) than in muscle (<3 mg CuxKg(-1) and 26 mg ZnxKg(-1)), while Pb and Cr were not detected. These results suggest that Cu and Zn are the metals of major concern in the lagoon. Mullet detritivorous feeding habits, bioaccumulation pattern and the high sediment metals concentrations relative to the water suggest that sediments can be the most important source of contamination in this ecosystem. The positive relationship found between Cu in liver and fish length demonstrates that time of exposure is a crucial factor in bioaccumulation. Condition indices (K and HSI) in mullets from the lagoon were higher compared to mullets from sea, suggesting abnormal condition in the lagoon population. We conclude that metals chronic exposure in the lagoon can impose considerable fish stress. The results also show that the lagoon is an area of environmental concern.

  15. Spatial and temporal variation of water quality in the coastal lagoons of Sinaloa

    NASA Astrophysics Data System (ADS)

    Paez-Osuna, F.; Lopez-Aguiar, L. K.; Del Río-Chuljak, A.; Ruiz-Fernandez, A. C.

    2007-05-01

    The Mexican state of Sinaloa has 656 km of coastline and 221,600 ha of coastal lagoons, and is characterized by a high fishing and agriculture activity. It is well known that agricultural activities constitute a major factor affecting the water quality in the coastal waters. The current study focused on the 6 more important coastal lagoons of Sinaloa (Topolobampo-Ohuira-Santa María, Navachiste-San Ignacio-Macapule, Santa María-La Reforma, Altata-Ensenada del Pabellón, Ceuta and Teacapán-Agua Brava) with the aim to evaluate the water quality spatial and temporal variation at the lagoons (physico-chemical parameters, nutrients (N, P and Si), dissolved oxygen, total suspended solids and chlorophyll a) and to assess its eutrophication status. The water samples were collected in several stations at each lagoon (between 9 and 23 stations depending on the lagoon area) at low and high tides, during three different weather periods (dry-warm, rainy and dry-cold seasons) between May 2004 and April 2005. Mean concentrations of nutrients (μM), dissolved oxygen (mg/L) and chlorophyll a (mg/m3) obtained for each variable were comparable between lagoons (total N=51±45; total P= 2.5±1.5; Si=23±31; DO=6.7±1.8; Chll=1.7±1.9) although seasonal and spatial differences were observed at each lagoon. The nutrient concentrations measured fell in the typical concentration intervals for coastal lagoons; however, critical sampling points were identified and related to direct discharges of untreated effluents from municipal wastes, aquaculture farms and agriculture drain ditches.

  16. Modeling the hydrodynamic interactions of deep anoxic lagoons with their source basins

    NASA Astrophysics Data System (ADS)

    Gianni, Areti; Zacharias, Ierotheos

    2012-09-01

    This study investigates the management of an extension of the anoxic water layers, from deeper to shallower environments, and aims to control the consequences in lagoon environments with great economic and ecological value. The physicochemical status in a deep anoxic lagoon (Aitoliko, Greece) was monitored and the spatial distribution of anoxic conditions in the bottom waters was the focal point. The study investigated the management of an extension of the anoxic water layers, from deeper to shallower environments, and aims to control the consequences in lagoon environments with great economic and ecological value. A three-dimensional numerical model was used in order to describe the hydrodynamic conditions in the lagoon. The model was calibrated and validated with field measurements and it was used as a tool to examine how morphological modifications in lagoon's sill and changes of the lagoon's salt/fresh water budget can affect water column hydrodynamics. The model reliably reproduced the hydrodynamic changes in the lagoon caused by morphological and/or hydraulic modification, demonstrating an ideal management plan for the control of deep anoxic hypolimnia. It is concluded that by decreasing fresh water discharges into a deep lagoon, epilimnetic density values increase while the metalimnion extends. By extending the sill's cross section, water fluxes with the source basin are increased, affecting the surface layer density. Even under these conditions fresh water discharges control the characteristics of a thin surface water layer. If the sill's cross section expansion is followed by a decrease of fresh water discharge, turbulence conditions in the water column of a deep basin are substantially affected.

  17. Stage-specific distribution models can predict eel (Anguilla anguilla) occurrence during settlement in coastal lagoons

    NASA Astrophysics Data System (ADS)

    Leone, C.; Zucchetta, M.; Capoccioni, F.; Gravina, M. F.; Franzoi, P.; Ciccotti, E.

    2016-03-01

    Eel (Anguilla anguilla) is a catadromous fish species typical of Mediterranean coastal lagoons, that currently suffers from several anthropogenic and natural impacts. These are thought to be the cause of a stock-wide decline that this panmictic species is facing, in inland and coastal waters of Europe and North Africa. The decline affects both adult phases and recruitment, i.e. glass eel arrival to coastal waters and their ascent to inland waters. Quantitative features of eel recruitment reflect a transoceanic global scale, but also depend on local environmental conditions, the latter also affecting settlement dynamics in transitional waters. There is only little information on the dynamics of these two processes in coastal lagoons, notwithstanding the paramount importance of both in sustaining local stocks abundance and their demographic structure for this typical but also economically important inhabitant of Mediterranean lagoons, habitats that constitute an important share of the eel distribution area. The present study aims, therefore, to clarify space and time dynamics of local scale recruitment and of settlement in a coastal lagoon in the Mediterranean area, also by setting up a specific methodological approach. For this purpose, data from field surveys in combination with Species Distribution Models (SDMs) have been used in order to relate distribution of eel juvenile stages to the environmental conditions within the lagoon. Specifically, models were calibrated to quantify the relationship between presence of juvenile eel and the main environmental drivers, with the aim of identifying potential habitats for eel settlement within the lagoon. Results gained by modelling suggest certain spatial and temporal colonization patterns for the juvenile eel in the Fogliano lagoon, a typical Mediterranean coastal lake. The modelling approach has therefore proved to be a useful tool for predicting habitats for eel recruitment at the local scale and settlement, because

  18. Lagoon-sea exchanges, nutrient dynamics and water quality management of the Ria Formosa (Portugal)

    NASA Astrophysics Data System (ADS)

    Newton, Alice; Mudge, Stephen M.

    2005-02-01

    Historical data from the Ria Formosa lagoon are classified according to the EEA 2001 guidelines to provide a frame of reference to evaluate the effect of management during the implementation of the environmental legislative Directives. Water samples from the Ria Formosa lagoon were significantly enriched in nitrogen (NH 4+ NO 2- and NO 3-) with respect to the adjacent coastal waters indicating that inputs from sewage, agricultural runoff and benthic fluxes were not fully assimilated within the lagoon. Tidal flushing was insufficient in the inner areas of the lagoon to remove or effectively dilute these inputs. Enrichment was most severe close to the urban centres of Faro and Olhão, as well as in the Gilão Estuary and the shallow extremities. Dissolved oxygen undersaturation (mean 75% during daylight hours) was associated with the area close to the sewage outlets of Faro. In the shallow west end of the lagoon during summer, dissolved oxygen supersaturation reached 140% during the day but fell to 50% at night. Classification using the EEA (2001) guidelines suggests the system is "poor" or "bad" with respect to phosphate concentrations for the majority of the year and "poor" in nitrogen contamination during the autumn rainy period. Due to the high overall nitrogen load in the lagoon, there is a net export to the coastal waters, especially during November and December, and phosphate only becomes limiting briefly during the spring bloom (April). Therefore, substantial phytoplankton populations may be supported year-round in the lagoon. The consequences of water quality deterioration in the Ria Formosa would negatively affect the lagoon as a regional resource, important for its ecological, economic and recreational value. The industries most affected would be tourism, fisheries and aquaculture. Management options include Urban Waste Water Treatment, dredging, artificial inlets, limits on urban development and changes in agricultural practices.

  19. The life cycle impact assessment applied to a coastal lagoon: the case of the Slimane lagoon (Tunisia) by the study of seasonal variations of the aquatic eutrophication potential

    NASA Astrophysics Data System (ADS)

    Hadj Amor, R.; Quaranta, G.; Gueddari, F.; Million, D.; Clauer, N.

    2008-05-01

    The life cycle impact assessment (LCIA) is a standard tool for the study of the environmental impact on a system including all activities in connection with manufacturing a product or detailing a service, from extraction of raw materials to disposal of final waste. Here, the system is not only anthropogenic, but also includes both natural behaviours and pollution aspects from human activity: it is a coastal lagoon with varied activities and waste disposals nearby. This stagnant zone is highly subjected to solar exposure and tends to dryness during summer, thus offering ideal conditions to algal proliferation. We have taken into account the trophic state of the lagoon assessed by the LCIA methodology, on the basis of the aquatic eutrophication potential (AEP). We have considered the concentrations of the phosphorus and nitrogen compounds for the calculation of the AEP and their spatial and temporal variations in the lagoon. The results show that the AEP of the phosphorus exceeds systematically the AEP of nitrogen and that the contents of both are systematically higher in summer than in winter. Nitrogen is the limiting factor for the algae growth. Ammonia and phosphates are the most important nutrients for the AEP in summer, whereas nitrates dominate in winter. In addition, the spatial and temporal variations of the N and P nutrients of the surface waters allow to distinguish three areas in the lagoon: a transition zone between the sea- and the lagoon waters; a zone reflecting directly the influence of the O. Bey creek- and the treated-waste waters and one representing the most isolated part of the lagoon and consequently the less contaminated by nutrient inputs.

  20. Inhibition of microbial metabolism in anaerobic lagoons by selected sulfonamides, tetracyclines, lincomycin, and tylosin tartrate

    USGS Publications Warehouse

    Loftin, Keith A.; Henny, Cynthia; Adams, Craig D.; Surampali, Rao; Mormile, Melanie R.

    2005-01-01

    Antibiotics are used to maintain healthy livestock and to promote weight gain in concentrated animal feed operations. Antibiotics rarely are metabolized completely by livestock and, thus, are often present in livestock waste and in waste-treatment lagoons. The introduction of antibiotics into anaerobic lagoons commonly used for swine waste treatment has the potential for negative impacts on lagoon performance, which relies on a consortium of microbes ranging from fermentative microorganisms to methanogens. To address this concern, the effects of eight common veterinary antibiotics on anaerobic activity were studied. Anaerobic microcosms, prepared from freshly collected lagoon slurries, were amended with individual antibiotics at 10 mg/L for the initial screening study and at 1, 5, and 25 mg/L for the dose-response study. Monitored metabolic indicators included hydrogen, methane, and volatile fatty acid concentrations as well as chemical oxygen demand. The selected antibiotics significantly inhibited methane production relative to unamended controls, thus indicating that antibiotics at concentrations commonly found in swine lagoons can negatively impact anaerobic metabolism. Additionally, historical antibiotic usage seems to be a potential factor in affecting methane production. Specifically, less inhibition of methane production was noted in samples taken from the lagoon with a history of multiple-antibiotic use.

  1. Revegetation of lagoon ash using the legume species Acacia auriculiformis and Leucaena leucocephala.

    PubMed

    Cheung, K C; Wong, J P; Zhang, Z Q; Wong, J W; Wong, M H

    2000-07-01

    A greenhouse study was conducted to evaluate the potential use of two legume species, Acacia auriculiformis and Leucaena leucocephala for growth on ameliorated lagoon ash with or without nitrogen (N(2))-fixing bacteria inoculation. Even though amendments of 30% (w/w) vermiculite or with sewage sludge compost were added to improve the chemical and physical limitations of lagoon ash, significant suppressions in biomass and plant nutrient content were found with ameliorated lagoon ash in comparison to an agricultural soil. The high proportion of clay-sized (<53 microm) ash particles limited root growth. In addition, heavy metal toxicity was a possible factor contributing to poor seedling growth. Higher plant productivity resulted from the sewage sludge compost-amended lagoon ash than with vermiculite due to a greater contribution of plant nutrients in the compost. Nodulation was inhibited in ameliorated lagoon ash but not in agricultural soil. High pH and electrical conductivity and elevated toxic metals may be important parameters that limit bacterial activity. Both species showed potential to establish on amended lagoon ash, with Acacia auriculiformis being the best adapted.

  2. Late Holocene sedimentation in a high Arctic coastal setting: Simpson Lagoon and Colville Delta, Alaska

    NASA Astrophysics Data System (ADS)

    Hanna, Andrea J. M.; Allison, Mead A.; Bianchi, Thomas S.; Marcantonio, Franco; Goff, John A.

    2014-02-01

    Arctic coastal environments near major river outfalls, like Simpson Lagoon, Alaska and the adjacent Colville River Delta, potentially contain high-resolution sediment records useful in elucidating late Holocene Arctic sediment transport pathways and coupled terrestrial-ocean evidence of paleoclimate variability. This study utilizes a multi-tracer geochronology approach (137Cs, 239,240Pu, and 14C) tailored for high-latitude environments to determine the age models for cores collected from Simpson Lagoon, and to date seismic boundaries in shallow acoustic reflection data (CHIRP) to examine late Holocene infill patterns. Modern (~100 y) sediment accumulation rates range from <0.02 to 0.46±0.04 cm y-1, with a primary depocenter in western Simpson Lagoon adjacent to the Colville Delta and a secondary depocenter in eastern Simpson Lagoon. CHIRP reflectors, age-constrained by 14C analysis, reveal rapid late Holocene (0-3500 y BP) transgression consistent with high modern shoreline retreat rates. The western depocenter contains >5 m of late Holocene interbedded sediments, likely derived primarily from the Colville River, with onset of accumulation occurring prior to ~3500 y BP. A paleo-high in central Simpson Lagoon, separating the two depocenters, was subaerially exposed prior to ~600 y BP. The millimeters-per-year sedimentation rates across the lagoon, coupled with the undisturbed, interbedded sediment record, indicate that these settings hold great potential to develop new Arctic paleoenvironmental records.

  3. Living in a coastal lagoon environment: photosynthetic and biochemical mechanisms of key marine macroalgae.

    PubMed

    García-Sánchez, Marta; Korbee, Nathalie; Pérez-Ruzafa, Isabel María; Marcos, Concepción; Figueroa, Félix L; Pérez-Ruzafa, Angel

    2014-10-01

    The physiological status of Cystoseira compressa, Padina pavonica and Palisada tenerrima was studied by in vivo chlorophyll fluorescence, pigment content, stoichiometry (C:N), accumulation of UV photoprotectors and antioxidant activity; comparing their photosynthetic response in a coastal lagoon (Mar Menor) and in Mediterranean coastal waters. In general, the specimens reached their highest ETRmax in spring in the Lagoon, but in summer in the Mediterranean, coinciding with their maximum biomass peak. The species exhibited a dynamic photoinhibition. Except C. compressa, they showed a lower decrease in Fv/Fm and higher recovery rates in the Mediterranean populations when exposed to high irradiance. The higher salinity and temperature of the lagoon could impair the photoprotection mechanisms. The acclimation to lagoon environments is species-specific and involves complex regulatory mechanisms. The results underline the importance of N in repair, avoidance, quenching and scavenging mechanisms. In general, Lagoon specimens showed higher pigment concentration. Although xanthophylls play important photo-protective and antioxidant roles, the observed trend is more likely to be explained by the higher temperatures reached in the lagoon compared to Mediterranean. Therefore the studied photosynthetic and biochemical mechanisms can be effective not only for high irradiance, but also for higher temperatures in a climate change scenario, but are highly dependent on nutrient availability.

  4. Cadmium, copper, lead, and zinc in Mugil cephalus from seven coastal lagoons of NW Mexico.

    PubMed

    Frías-Espericueta, Martin G; Osuna-López, J Isidro; Jiménez-Vega, Martha A; Castillo-Bueso, Daniel; Muy-Rangel, Maria D; Rubio-Carrasco, Werner; López-López, Gabriel; Izaguirre-Fierro, Gildardo; Voltolina, Domenico

    2011-11-01

    The increasing order of the mean concentrations of Cd, Cu, and Zn in the tissues of Mugil cephalus of seven coastal lagoons of Sinaloa State (NW Mexico) was liver > gills > muscle, while for Pb it was gills > muscle ≥ liver. There were no differences between the mean concentrations of Cd and Pb of the three tissues determined in the samples of the seven lagoons and, although there were some significant differences, there was no indication of a latitude-related trend in the distribution of Cu and Zn: the Cu content of the muscle tended to be higher in the northern than in the southern lagoons, although in the case of the gills the highest and lowest mean values indicated an opposite trend, with the highest and lowest values in one southern and one northern lagoon. In the case of the liver, there were no differences and no indication of a regional trend. There were no differences in the mean Zn contents of muscle and gills; in the case of the liver, one of the lagoons of the central part of the state had a significantly higher value than one of the southern lagoons and all the rest had similar values. In addition, there was no clear indication of season-related differences in any of the three tissues. According to our results, the metal contents of the muscle of this species are not of concern for human health, since the allowable ingestion would be in the order of 0.9 kg/day.

  5. Sustainability assessment of traditional fisheries in Cau Hai lagoon (South China Sea).

    PubMed

    Marconi, Michele; Sarti, Massimo; Marincioni, Fausto

    2010-01-01

    Overfishing and progressive environmental degradation of the Vietnamese Cau Hai coastal lagoon appear to be threatening the ecological integrity and water quality of the largest estuarine complex of Southeast Asia. This study assessed the relationships between the density of traditional fisheries and organic matter sedimentary contents in Cau Hai lagoon. Data revealed that the density of stake traps (the most common fishing gear used in this lagoon), decreasing hydrodynamic energy in shallow water, causes the accumulation of a large fraction of organic matter refractory to degradation. The relationship between biopolymeric carbon (a proxy of availability of organic matter) and stake traps density fits a S-shape curve. The logistic equation calculated a stake traps density of 90 m of net per hectare, as the threshold over which maximum accumulation of organic matter occurs in Cau Hai. With such level of stake trap density, and assuming a theoretical stationary status of the lagoon, the time necessary for the system to reach hypoxic conditions has been calculated to be circa three weeks. We recommend that this density threshold should not be exceeded in the Cau Hai lagoon and that further analyses of organic loads in the sediment should be conducted to monitor the trophic conditions of this highly eutrophicated lagoon.

  6. Rates of sediment supply and sea-level rise in a large coastal lagoon

    USGS Publications Warehouse

    Morton, R.A.; Ward, G.H.; White, W.A.

    2000-01-01

    Laguna Madre, Texas, is 3-7 km wide and more than 190 km long, making it one of the longest lagoons in the world. The lagoon encompasses diverse geologic and climatic regions and it is an efficient sediment trap that accumulates clastic sediments from upland, interior, and oceanic sources. The semi-arid climate and frequent tropical cyclones historically have been responsible for the greatest volume of sediment influx. On an average annual basis, eolian transport, tidal exchange, storm washover, mainland runoff, interior shore erosion, and authigenic mineral production introduce approximately one million m3 of sediments into the lagoon. Analyses of these sediment transport mechanisms and associated line sources and point sources of sediment provide a basis for: (1) estimating the long-term average annual sediment supply to a large lagoon; (2) calculating the average net sedimentation rate; (3) comparing introduced sediment volumes and associated aggradation rates with observed relative sea-level change; and (4) predicting future conditions of the lagoon. This comparison indicates that the historical average annual accumulation rate in Laguna Madre (<1 mm/yr) is substantially less than the historical rate of relative sea-level rise (~4 mm/yr). Lagoon submergence coupled with erosion of the western shore indicates that Laguna Madre is being submerged slowly and migrating westward rather than filling, as some have suggested.

  7. Restoration of the eutrophic Orbetello lagoon (Tyrrhenian Sea, Italy): water quality management.

    PubMed

    Lenzi, Mauro; Palmieri, Roberto; Porrello, Salvatore

    2003-12-01

    The Orbetello lagoon (Tyrrhenian coast, Italy) receives treated urban and land based fishfarms wastewater. The development of severe eutrophication imposed the three main activity adoption focuses on (1) macroalgae harvesting; (2) pumping of water from the sea; (3) confining wastewater to phytotreatment ponds. The responses to these interventions were rapid and macroalgal reduction growth and seagrass return were recorded. Since 1999, a new macroalgal development was recorded. The aim of this research was to discover whether the recent macroalgal growth can be attributed to the continuing wastewater influx from the remaining persistent anthropic sources (PAS) or from the sediment nutrient release. A monitoring programme was carried out between August 1999 and July 2000 in order to measure dissolved inorganic nitrogen and phosphorus in the wastewaters entering into the lagoon and in central lagoon areas, seaweed and seagrass distribution and lagoon N, P annual budgets. The results showed higher N and P values close to PAS. The distribution of the macroalgal species confirms that the available P comes almost entirely from these remaining PAS. In conclusion, the environmental measures adopted produced a significant reduction in algal biomass development in the lagoon; the macroalgal harvesting activities produced a sediment disturbance with following oxidize conditions, which make P unavailable in the lagoon water, excepting close the PAS.

  8. Distribution and sources of carbon, nitrogen, phosphorus and biogenic silica in the sediments of Chilika lagoon

    NASA Astrophysics Data System (ADS)

    Nazneen, Sadaf; Raju, N. Janardhana

    2017-02-01

    The present study investigated the spatial and vertical distribution of organic carbon (OC), total nitrogen (TN), total phosphorus (TP) and biogenic silica (BSi) in the sedimentary environments of Asia's largest brackish water lagoon. Surface and core sediments were collected from various locations of the Chilika lagoon and were analysed for grain-size distribution and major elements in order to understand their distribution and sources. Sand is the dominant fraction followed by silt + clay. Primary production within the lagoon, terrestrial input from river discharge and anthropogenic activities in the vicinity of the lagoon control the distribution of OC, TN, TP and BSi in the surface as well as in the core sediments. Low C/N ratios in the surface sediments (3.49-3.41) and cores (4-11.86) suggest that phytoplankton and macroalgae may be major contributors of organic matter (OM) in the lagoon. BSi is mainly associated with the mud fraction. Core C5 from Balugaon region shows the highest concentration of OC ranging from 0.58-2.34%, especially in the upper 30 cm, due to direct discharge of large amounts of untreated sewage into the lagoon. The study highlights that Chilika is a dynamic ecosystem with a large contribution of OM by autochthonous sources with some input from anthropogenic sources as well.

  9. Phytoplankton community dynamics in an intermittently open hypereutrophic coastal lagoon in southern Portugal

    NASA Astrophysics Data System (ADS)

    Coelho, Susana; Pérez-Ruzafa, Angel; Gamito, Sofia

    2015-12-01

    Phytoplankton community' dynamics were studied in Salgados coastal lagoon in order to evaluate the effects of excessive organic loads and also physical stress caused by the irregular opening of the lagoon. Salgados is a hypereutrophic intermittently open coastal lagoon, which received freshwater inputs from small rivers and from a wastewater treatment plant. Cyanophyceae dominated the phytoplankton communities most of the time; Bacillariophyceae became the main taxonomic group in winter when the lagoon was closed; Chlorophyceae was the major class in early summer; pico-nano flagellate algae accounted for a high percentage of total phytoplankton during spring. Potentially harmful taxa were observed during most of the sampling periods, forming blooms and accounting for a considerable percentage of total phytoplankton abundance. A strong differentiation among dry and wet seasons could be noticed. The dry season was dominated by Microsystis aeruginosa, Rhodomonas sp., pico-nano flagellate algae, Cyclotella spp. and Planktothrix sp., while the wet season, although still with the presence of Microsystis aeruginosa, was dominated by Dolichospermum spiroides. The best environmental variables explaining stations patterns and based on phytoplankton taxa were days of isolation, pH, and salinity. Temperature, cumulative rain and total phosphorus were also related with species and stations patterns. The high nutrient load in Salgados lagoon promoted the development and persistence of harmful algae blooms. Proper management of coastal lagoons involves not only the control of direct discharges of nutrients, but also of other factors, including water level and communication with the sea.

  10. Self-powered wastewater treatment for the enhanced operation of a facultative lagoon

    NASA Astrophysics Data System (ADS)

    Ewing, Timothy; Babauta, Jerome T.; Atci, Erhan; Tang, Nghia; Orellana, Josue; Heo, Deukhyoun; Beyenal, Haluk

    2014-12-01

    The goal of this study was to harness the redox gradients in facultative lagoons using a lagoon microbial fuel cell (LMFC) to enhance autonomously the delivery of oxygen to the lagoon through aeration and mixing by operating an air pump. To enhance the usability of the low power generated by the LMFC, a power management system (PMS) was used to harvest power continually while only operating the air pump intermittently. Here we demonstrate the LMFC as an alternative energy source for self-powered wastewater treatment systems by treating both artificial wastewater and dairy wastewater in large laboratory-scale simulated lagoons. For comparison, we also used a lagoon treatment system without self-aeration. We show that the integrated LMFC and PMS system was able to improve chemical oxygen demand (COD) removal time by 21% for artificial wastewater and by 54% for dairy wastewater. The LMFC-PMS wastewater treatment system operated for over a year and proved to be robust and provide a measure of sustainability. The LMFC-PMS combination offers an innovative and low-tech approach to increasing the capacity of lagoons for rural communities. We believe that the technology developed in this research is the first step towards providing sustainable self-powered wastewater treatment systems.

  11. Water quality of Mediterranean coastal plains: conservation implications from the Akyatan Lagoon, Turkey.

    PubMed

    Demir Yetis, Aysegul; Selek, Zeliha; Seckin, Galip; Davutluoglu, Orkun I

    2014-11-01

    The water quality of the Akyatan Lagoon was characterized using hydrochemical methodology. The lagoon is located on the Mediterranean coast and is the largest wetland ecosystem in Turkey. In addition, the lagoon is classified as a hyper-salinity wetland. Water samples were collected monthly between December 2007 and November 2008. Eleven stations within the lagoon were determined, and triplicate grab samples were obtained from each station to characterize water quality as follows: T °C, pH, total alkalinity (TAlk), dissolved oxygen (DO), total dissolved solids (TDS), salinity, electrical conductivity (EC), and main anions, including chloride (Cl(-)), nitrates (NO3 (-)), and sulfate (SO4 (2-)). Results from selected stations indicated varying TDS, EC, salinity, and Cl(-) concentrations, from 20,892 to 175,824 mg/L, from 35.7 to 99.6 mS/cm, from 22.3 to 71.0 ppt, and from 14,819 to 44,198 mg Cl(-)/L, respectively. Data indicated that the spatial distribution of water quality parameters was significantly affected by freshwater input via the constructed drainage channels which collect water from a catchment area and discharge water into the lagoon as a point source, thus preventing drainage water to reach the lagoon as a nonpoint source.

  12. Non-steady-state modelling of faecal coliform removal in deep tertiary lagoons.

    PubMed

    Xu, P; Brissaud, F; Fazio, A

    2002-07-01

    In Noirmoutier, a French island off the Atlantic coast, secondary effluents flow into a series of four lagoons, 1.4-2.8 m deep, and are reused for agricultural irrigation. The excess water is disposed of to the sea. The aim of this study was to provide a model capable of predicting the microbiological quality of the water pumped for irrigation or discharged to the sea. Meteorological variables, flow rates, physical-chemical characteristics and faecal coliform (FC) contents were monitored for a year and a half. The hydraulic pattern of each lagoon was assumed to be that of completely mixed reactor because of the calculated dispersion numbers and the wind mixing effect. Coliform decay was assumed to follow first order kinetics in each lagoon. Die-off coefficients were calculated in each lagoon using a non-steady-state model. The main bacterial removal mechanism was shown to be solar irradiation. Empirical equations were established to calculate die-off coefficients as a function of received solar energy and temperature. FC die-off rates were higher in the first lagoon and then decreased successively in those following. FC numbers in the different lagoons were predicted with reasonable accuracy in spite of high variation in inlet water quality. The model will facilitate the prediction of water quality under various climatic conditions and different water reuse scenarios and will help to optimise reclamation and storage facilities.

  13. A GIS Approach for Reconstructing the Litorina Sea Lagoon in Tolkuse-Rannametsa Area, Eastern Gulf of Riga.

    NASA Astrophysics Data System (ADS)

    Habicht, Hando-Laur; Rosentau, Alar; Jõeleht, Argo; Hang, Tiit; Kohv, Marko

    2015-04-01

    The eastern coast of the Gulf of Riga in the NE Baltic Sea is characterized by slow post-glacial isostatic uplift (about 1mm/yr) and slowly undulating low topography. Therefore even small increases in sea-level can easily lead to the flooding of considerable areas. The complex deglaciation history of the Baltic Sea area left, at times, south western Estonia submerged, while at other times, it emerged as terrestrial land. Different transgressive and regressive development stages of the Baltic Sea did not only shape the landscape, but also influenced the locations of the Stone Age settlements which were closely bound to the coastal areas which also include estuaries and lagoonal systems. The coastal region of the Gulf of Riga is abundant in Meso- and Neolithic settlement sites. The present study combines LiDAR, ground-penetrating radar (GPR) and geological data to reconstruct development of the Litorina Sea lagoon in Tolkuse-Rannametsa area and to create prognostic palaeogeographic maps in order to search for Meso- and Neolithic coastal settlement sites. Over 47 km of GPR profiling was done; sediments were described and dated in 37 cores two riverbank outcrops. Diatoms were analysed in the master core. A semi-automatic method for the removal of modern anthropogenic features from LiDAR derived digital elevation model (DEM) was developed, tested and used. In modelling process the impact of sedimentary processes subsequent to the time being modelled was taken into account by employing a backstripping methodology. The differential glacio-isostatic uplift within the study area was taken into account by using interpolated water-level surfaces. Palaeogeographic reconstructions shed new light into region's post-glacial coastal evolution and enabled us to suggest the possible locations of the Stone Age settlements with some of the proposed areas buried under up to 3 m thick peat layer. The results of the current study provide new chronological and shore displacement data

  14. Data ingestion into NeQuick 2

    NASA Astrophysics Data System (ADS)

    Nava, B.; Radicella, S. M.; Azpilicueta, F.

    2011-12-01

    NeQuick 2 is the latest version of the NeQuick ionosphere electron density model developed at the Aeronomy and Radiopropagation Laboratory of the Abdus Salam International Centre for Theoretical Physics (ICTP) - Trieste, Italy with the collaboration of the Institute for Geophysics, Astrophysics and Meteorology of the University of Graz, Austria. It is a quick-run model particularly designed for trans-ionospheric propagation applications that has been conceived to reproduce the median behavior of the ionosphere. To provide 3-D specification of the ionosphere electron density for current conditions, different ionosphere electron density retrieval techniques based on the NeQuick adaptation to GPS-derived Total Electron Content (TEC) data and ionosonde measured peak parameters values have been developed. In the present paper the technique based on the ingestion of global vertical TEC map into NeQuick 2 will be validated and an assessment of the capability of the model to reproduce the ionosphere day-to-day variability will also be performed. For this purpose hourly GPS-derived global vertical TEC maps and hourly foF2 values from about 20 ionosondes corresponding to one month in high solar activity and one month in low solar activity period will be used. Furthermore, the first results concerning the ingestion of space-based GPS-derived TEC data will be presented.

  15. MiniBooNE oscillation searches

    SciTech Connect

    Brice, Stephen J.

    2008-01-01

    The range of oscillation analyses being pursued by the MiniBooNE collaboration is described. Focus is given to the various searches for electron neutrino appearance, but the disappearance of muon neutrinos and the appearance search for electron anti-neutrinos are covered as well.

  16. Impacts of climate change on water resources in watersheds of four European lagoons

    NASA Astrophysics Data System (ADS)

    Stefanova, Anastassi; Hesse, Cornelia; Krysanova, Valentina

    2014-05-01

    The hydrologic impacts of projected climate change were assessed for the drainage areas of four European lagoons: the Ria de Aveiro lagoon in Portugal, the Mar Menor lagoon in Spain, the Vistula lagoon in Poland and Kaliningrad region and the Tyligulski lagoon in Ukraine. The eco-hydrological model SWIM (Soil and Water Integrated Model) was applied to each of the four case study areas individually, considering basin-specific characteristics and management settings. All four watersheds were calibrated and validated towards river discharge at one or more gauges, reaching satisfactory to very good modelling results, depending on the quality and availability of input data (i.e. observed climate and discharge data). For the assessment of climate change impacts we forced the four model set-ups with scenario data from the ENSEMBLES project. Therefore a set of 15 climate scenarios, all running until the end of the 21st century, was applied to SWIM for one reference and three future periods of 30 years each. We evaluated the long-term changes of total freshwater inflow to the four lagoons and compared the results considering average trends and uncertainties induced by the different climate scenarios. The comparison not only shows differences in the magnitude of potential impacts among the four regions but also differences in the direction of change. In Spain and Portugal an average decrease in discharge of about -5% and -15% can be expected, while at the same time the total inflow to the Vistula and the Tyligulski lagoon is projected to increase by 18% and 20% on average by the end of the century. The agreement of climate projections among scenarios is varies between regions and in consequence the uncertainty in model outputs also differs between the four case studies. In the watershed of the Tyligulski lagoon the projected changes in river discharge vary between -70% and 120%, whereas the results for the Ria de Aveiro lagoon range between -1% and -27% for the last three

  17. Storm-water characterization and lagoon sediment analysis, Grand Forks Air Force Base, North Dakota. Final report

    SciTech Connect

    Garland, J.G.; Vaughn, R.W.; Scott, P.T.

    1990-08-01

    Sampling was conducted in the wastewater treatment lagoons and stormwater runoff at Grand Forks AFB. The base was concerned about whether the unlined lagoons were creating a potential groundwater contamination problem and whether their stormwater runoff met North Dakota state stream standards. Lagoon sediment did not contain Extraction Procedure hazardous chemicals. Stormwater runoff exceeded state standards for boron, phosphates, and phenols and contained trace levels of methylene chloride. Characterization of lagoon influent showed it to be generally representative of domestic sewage, but also contained trace levels of boron, phenols, toluene, cyanide, chloroform, methylene chloride and ethyl benzene.

  18. Parasite communities of the neotropical cormorant Phalacrocorax brasilianus (Gmelin) (Aves, Phalacrocoracidae) from two coastal lagoons in Guerrero state, Mexico.

    PubMed

    Violante-González, Juan; Monks, Scott; Gil-Guerrero, Salvador; Rojas-Herrera, Agustín; Flores-Garza, Rafael; Larumbe-Morán, Edvino

    2011-11-01

    The parasite community structure of the neotropical cormorant, Phalacrocorax brasilianus, from two lagoons (Coyuca and Tres Palos) from Guerrero state, México, was examined. Fourteen species of adult helminths (6,391 individuals) from 48 cormorants were identified: 9 digeneans, 1 acanthocephalan, 1 cestode, and 3 nematodes. A total of 11 species were collected in Coyuca Lagoon and 12 in Tres Palos Lagoon. Nine species co-occurred in cormorants of both lagoons but, with the exception of Contracaecum multipapillatum and Drepanocephalus olivaceus, species were not equally common in both lagoons. The prevalence values of six species of helminth and the mean abundance of four species varied significantly between lagoons, and C. multipapillatum was numerically dominant in both lagoons. The qualitative similarity between the two communities at the component level was 64%. All cormorants examined were infected, and parasite species richness was 3-5 in Coyuca and 4-9 in Tres Palos lagoon. The results indicate that both communities presented a similar structure at the component level, probably because the cormorants of both lagoons feed on the same species of fish and thus acquire almost the same species of parasites. Differences observed at the infracommunity level were attributed to variations in the degree of dominance of the particular species.

  19. The distribution of salinity and main forcing effects in the Berre lagoon

    NASA Astrophysics Data System (ADS)

    Roux, Bernard; Alekseenko, Elena; Chen, Paul Gang; Kharif, Christian; Kotarba, Richard; Fougere, Dominique

    2014-05-01

    The results from previous studies in lagoons and well mixed estuaries indicate that salt transport is primarily in response to advection associated with freshwater outflow, tidal diffusion, and to shear effects arising from spatial correlations of vertical and especially transverse deviations in salinity and current speed (Smith, 1994). Therefore, the inflow of fresh and salt water into coastal lagoons is an important factor influencing the structure and function of lagoonal ecosystems worldwide (Lirman et al., 2007). The predominance of marine or freshwater inflow leads to the different ecosystems. Among several lagoons located along the Mediterranean shore of France, the Berre lagoon has been under intense anthropogenic pressure for several decades (Delpy et al., 2012). Moreover, the salinity level of the Berre lagoon was varying dramatically from the 19th century up to now. In this work, a special attention is focused on the salinity variation in the Berre lagoon due to the three dominant abiotic forcing mechanisms, i.e., incoming sea tide, runoff from a hydropower and a strong wind. Four different model scenarios were considered in order to examine the impact of each forcing mechanism or combined effects, i.e. : (a) tide only, (b) runoff only, (c) combined tide and runoff, and (d) an N-NW wind, tide and runoff together. Numerical modeling and interpretation of numerical results are based on three-dimensional hydrodynamic model MARS3D. It is found that the strongest negative impact is related to the huge hydropower runoffs, inducing the desalinization of the surface and subsurface waters not only in the centre of the lagoon, but also in the entire water column in the coastal seagrass recolonization zones. In the absence of wind, the huge inputs of freshwater from the hydropower lead to a haline stratification and thus, to anoxic conditions, making most of the lagoon unproductive. On the contrary, strong winds play a positive role on the salinity level of the

  20. Calculation of electron wave functions and refractive index of Ne

    NASA Astrophysics Data System (ADS)

    Zhu, Min; Liu, Wei; Zhang, Tao

    2008-10-01

    The radial wave functions of inner electron shell and outer electron shell of a Ne atom were obtained by the approximate analytical method and tested by calculating the ground state energy of the Ne atom. The equivalent volume of electron cloud and the refractive index of Ne were calculated. The calculated refractive index agrees well with the experimental result. Relationship between the refractive index and the wave function of Ne was discovered.

  1. New Caledonia surface lagoon chlorophyll modeling as coastal reef area health indicator

    NASA Astrophysics Data System (ADS)

    Fuchs, R.; Pinazo, C.; Douillet, P.; Dupouy, C.; Faure, V.; Mangin, A.

    2010-10-01

    The major part of the New Caledonia (NC) lagoon was classified as UNESCO Natural Site of Humanity Patrimony. Indeed, 22 175 km2 of tropical coral lagoon area exhibit high biodiversity. The NC lagoon is semi enclosed and connected to the Coral Sea through a barrier reef segmented by narrow passes. The environment is oligotrophic, due to important flush during trade winds events, and bathymetry is highly variable. In order to predict eutrophication events, we used an extension of a 3D coupled physical-biogeochemical model recently developed on NC south western lagoon. The model is based on the Nitrogen and Carbon cycles, relating the variable stoechiometry of the elements in each biological compartment. The ecological model was developed to include an explicit description of the microbial loop. The resulting coupled model, forced by tide, wind, light, temperature and freshwater inputs, was used to calculate phytoplankton biomass, bacterial production, dissolved organic matter concentrations and nutrient recycling. Here we present results issued from the 3D coupled model ECO3M_LAGOON (biogeochemical, LOPB-IRD) and MARS3D (regional physical model, IFREMER-IRD) describing spatial and temporal interactions between water motion and biology, on larger domain including reef barrier and water exchanges through ocean-lagoon interface. To validate physical processes in the lagoon we used in situ data collected during field cruise (ValHyBio 2008, La Niña episode). Surface chlorophyll concentrations are compared with water color data from ValHyBio cruise and satellite data (MODIS/MERIS) corrected from bathymetry effects.

  2. The Unare lagoon - A recent example of sequence stratigraphic control in reservoir patterns

    SciTech Connect

    Bejarano, C. )

    1993-02-01

    The Unare lagoon constitutes a barred coastal lagoon formed during the Holocene transgression on a moderate wave energy, microtidal coast. An extensive surface sampling and core drill program has been carried out in the lagoon in order to develop a reservoir sedimentology and sequence stratigraphic model applicable to similar subsurface deposits. During the rapid Halocene sea level rise, more than 70 m of fluvial and delta plain sediments have aggraded behind the landward stepping coastal barrier. These sediments are truncated seaward by a transgressive wave ravinement surface, and are capped by widespread lagoonal muds which accumulated between 8300 and 7250 yBP. These muds constitute the Holocene Maximum Flooding Surface which preceded the onset of the post Holocene stillstand (c. 500[approximately] yBP), probably as a result of the high rate of sediment supply and the confined nature of the lagoon which acted as an efficient sediment trap. During the post Holocene stillstand, a fluvial-dominated delta has prograded across the lagoon and attained the coastal barrier. This delta constitutes a Highstand Systems Tract. The major reservoir sands comprise distributary channel meanderbelts and the transgressive barrier. The channels form sand ribbons 5-7 m thick, and up to 2 km wide. The barrier and shoreface sands forms a strike-elongate deposits less than 5 m thick, up to 150-600 m wide, and 5-10 km long. The lagoonal facies of the Maximum Flooding Surface form a good reservoir seal overlying the aggrading transgressive fluvial and delta plain sands and muds.

  3. Resistance of polychaete species and trait patterns to simulated species loss in coastal lagoons

    NASA Astrophysics Data System (ADS)

    Faulwetter, Sarah; Papageorgiou, Nafsika; Koulouri, Panayota; Fanini, Lucia; Chatzinikolaou, Eva; Markantonatou, Vasiliki; Pavloudi, Christina; Chatzigeorgiou, Georgios; Keklikoglou, Kleoniki; Vasileiadou, Katerina; Basset, Alberto; Pinna, Maurizio; Rosati, Ilaria; Reizopoulou, Sofia; Nicolaidou, Artemis; Arvanitidis, Christos

    2015-04-01

    The loss of species is known to have negative impacts on the integrity of ecosystems, but the details of this relationship are still far from being fully understood. This study investigates how the distribution patterns of polychaete species and their associated biological trait patterns in six Mediterranean coastal lagoons change under computationally simulated scenarios of random species loss. Species were progressively removed from the full polychaete assemblage and the similarity between the full assemblage and the reduced matrices of both species and trait patterns was calculated. The results indicate the magnitude of changes that might follow species loss in the real world, and allow consideration of the resistance of the system's functional capacity to loss of species, expressed through the species' biological traits as an approximation to functioning. Comparisons were made between the changes in the distribution of species and of traits, as well as between the six different lagoons. While the change of species and trait patterns was strongly correlated within most lagoons, different lagoons showed distinctly different patterns. In disturbed lagoons, the dominance of one or few species was the major driver for the observed patterns and the loss of these species caused extreme changes. Less disturbed lagoons were less susceptible to extreme changes and had a greater resistance towards species loss. Species richness appears to be less important for the ability of the lagoons to buffer changes, instead the initial composition of the assemblage and the identity of the lost species determine the response of the system and our ability to predict changes of the assemblage's functional potential.

  4. Hydrologic characteristics of lagoons at San Juan, Puerto Rico, during an October 1974 tidal cycle

    USGS Publications Warehouse

    Gómez-Gómez, Fernando; Ellis, S.R.

    1983-01-01

    Flow and water-quality changes were studied during a period of intense rainfall in the San Juan Lagoon system. The study covered a 25-hour period beginning 0900 hours 22 October, 1974. Precipitation during the study period averaged 70 millimeters. Sampling stations were located at Boca de Cangrejos, the main ocean outlet; Canal Pinones between Laguna de Pinones and Laguna La Torrecilla; Canal Suarez between Laguna San Jose, connects to Laguna La Torrecilla; and Cano de Martin Pena between Laguna San Jose and Bahia de San Juan. In addition water-elevation recording gages were installed at each lagoon. Water samples from the canal stations were analyzed for organic carbon, nitrogen and phosphorus species, and suspended sediment. Specific-conductance measurements were used with the chemical data to estimate the runoff contributions of nutrients. Runoff into the lagoon, system during the study period was about 2.8 million cubic meters, or about 70 percent of the average precipitation. The runoff contributed chemical loadings to the lagoons of 95,000 kilograms total-organic carbon; 2,700 kilograms of total phosphorus; and 10,000 kilograms of total Khjeldhal nitrogen. A comparison with a prior study during which there was no significant rain, show that dry-period loadings are less than 10 percent of the wet-period loadings. At the end of the study period the system had not reached equilibrium, and the lagoons retained 80 percent of the water inflows from 50 to 90 percent of the chemical loads. Nearly 95 percent of the water outflows occurred at the Boca de Cangrejos sea outlet. The three lagoons and interconnecting canals form a very complex hydraulic system that is difficult to study using traditional techniques. A model of the system will facilitate management to improve the quality of water in the lagoons.

  5. Marshall Islands Fringing Reef and Atoll Lagoon Observations of the Tohoku Tsunami

    NASA Astrophysics Data System (ADS)

    Ford, Murray; Becker, Janet M.; Merrifield, Mark A.; Song, Y. Tony

    2014-12-01

    The magnitude 9.0 Tohoku earthquake on 11 March 2011 generated a tsunami which caused significant impacts throughout the Pacific Ocean. A description of the tsunami within the lagoons and on the surrounding fringing reefs of two mid-ocean atoll islands is presented using bottom pressure observations from the Majuro and Kwajalein atolls in the Marshall Islands, supplemented by tide gauge data in the lagoons and by numerical model simulations in the deep ocean. Although the initial wave arrival was not captured by the pressure sensors, subsequent oscillations on the reef face resemble the deep ocean tsunami signal simulated by two numerical models, suggesting that the tsunami amplitudes over the atoll outer reefs are similar to that in deep water. In contrast, tsunami oscillations in the lagoon are more energetic and long lasting than observed on the reefs or modelled in the deep ocean. The tsunami energy in the Majuro lagoon exhibits persistent peaks in the 30 and 60 min period bands that suggest the excitation of closed and open basin normal modes, while energy in the Kwajalein lagoon spans a broader range of frequencies with weaker, multiple peaks than observed at Majuro, which may be associated with the tsunami behavior within the more irregular geometry of the Kwajalein lagoon. The propagation of the tsunami across the reef flats is shown to be tidally dependent, with amplitudes increasing/decreasing shoreward at high/low tide. The impact of the tsunami on the Marshall Islands was reduced due to the coincidence of peak wave amplitudes with low tide; however, the observed wave amplitudes, particularly in the atoll lagoon, would have led to inundation at different tidal phases.

  6. Reconstruction of historic sea ice conditions in a sub-Arctic lagoon

    USGS Publications Warehouse

    Petrich, Chris; Tivy, Adrienne C.; Ward, David H.

    2014-01-01

    Historical sea ice conditions were reconstructed for Izembek Lagoon, Bering Sea, Alaska. This lagoon is a crucial staging area during migration for numerous species of avian migrants and a major eelgrass (Zostera marina) area important to a variety of marine and terrestrial organisms, especially Pacific Flyway black brant geese (Branta bernicla nigricans). Ice cover is a common feature of the lagoon in winter, but appears to be declining, which has implications for eelgrass distribution and abundance, and its use by wildlife. We evaluated ice conditions from a model based on degree days, calibrated to satellite observations, to estimate distribution and long-term trends in ice conditions in Izembek Lagoon. Model results compared favorably with ground observations and 26 years of satellite data, allowing ice conditions to be reconstructed back to 1943. Specifically, periods of significant (limited access to eelgrass areas) and severe (almost complete ice coverage of the lagoon) ice conditions could be identified. The number of days of severe ice within a single season ranged from 0 (e.g., 2001) to ≥ 67 (e.g., 2000). We detected a slight long-term negative trend in ice conditions, superimposed on high inter-annual variability in seasonal aggregate ice conditions. Based on reconstructed ice conditions, the seasonally cumulative number of significant or severe ice days correlated linearly with mean air temperature from January until March. Further, air temperature at Izembek Lagoon was correlated with wind direction, suggesting that ice conditions in Izembek Lagoon were associated with synoptic-scale weather patterns. Methods employed in this analysis may be transferable to other coastal locations in the Arctic.

  7. Chlorinated hydrocarbons in coastal lagoons of the pacific coast of Nicaragua.

    PubMed

    Carvalho, F P; Montenegro-Guillen, S; Villeneuve, J; Cattini, C; Bartocci, J; Lacayo, M; Cruz, A

    1999-02-01

    A screening for persistent chlorinated hydrocarbons was carried out in December 1995 in the main coastal lagoons on the Pacific side of Nicaragua, where most of the country's agriculture and pesticide use has been taking place for decades. Results for a wide range of organochlorine pesticides in lagoon sediments show levels that generally were very low in Estero Real, Estero Padre Ramos, and estuary of San Juan del Sur. For example, total DDTs in these lagoons averaged 4.5 +/- 3.4 ng g-1 dry weight, which may be considered a baseline level for the region. Other compounds such as HCHs, BHC, endosulfan, heptachlor, endrin, toxaphene, and aroclors were present in concentrations even lower, generally below 1 ng g-1 dry weight. However, sediments of the Esteros Naranjo-Paso Caballos system at Chinandega district contained pesticide residues in much higher levels, attaining maximum values of 1,420 ng g-1 and 270 ng g-1 dry weight, respectively, for toxaphene and total DDTs. Other compounds such as aroclors, chlordane, endosulfan, and dieldrin were also present in the sediments of this lagoon system, but in lower concentrations. The very high concentrations of toxaphene and DDTs in this lagoon are a result of the intensive use of these pesticides in cotton growing in the district of Chinandega. Due to the long environmental half-lives of these compounds (t(1/2) > 10 years in temperate soils), their concentrations in lagoon sediments will likely remain high for years to come. Based on these results, the development of the new shrimp farming activities in the Pacific coastal lagoons should be restricted to selected areas.

  8. Primary production dynamics in a pristine groundwater influenced coastal lagoon of the Yucatan Peninsula

    NASA Astrophysics Data System (ADS)

    Medina-Gómez, Israel; Herrera-Silveira, Jorge A.

    2006-06-01

    Dzilam lagoon is a shallow (0.6 m mean depth) ecosystem with 9.4 km 2 surface area, located in the north coast of the Yucatan Peninsula, and connected to the Gulf of Mexico through a permanent inlet. Freshwater input is possible through numerous sinkholes distributed throughout the lagoon, which also represent a continuous source of nitrate and silicate. The low anthropogenic influence has maintained a pristine condition in Dzilam lagoon, manifested in a spatial heterogeneity of water quality and primary production strongly related to the environmental fluctuations. To determine the annual variability of primary production and identify the factors controlling it, 12 monthly samplings were undertaken at six stations, from September 1998 to August 1999. Thus, physical-chemical parameters, inorganic nutrients concentrations, chlorophyll- a, phytoplankton production and seagrass biomass were measured. The water residence time in Dzilam lagoon is higher during dry season due to the significant evaporation rate, and shorter in rainy season because of increase in precipitation and volume of groundwater discharge. The multivariate analysis results suggest that the salinity gradient, changes in aquatic vegetation biomass, and the remineralized nutrients in sediments constitute key processes depicting the water quality and net primary production in Dzilam lagoon. Furthermore, the biogeochemical benthic processes, combined with a longer stay of phytoplankton cells within the lagoon, enhanced primary production in the water column during dry season, as opposite as rainy period, when the inferior water residence time yielded lower production values. The seagrasses ( Halodule wrightii and Ruppia maritima) showed the highest biomass (110.5 g dw/m 2/d) in dry season, while the lowest recordings were observed during cold fronts, with a salient belowground contribution (rhizomes and roots). Seagrasses and phytoplankton participation to the total primary production in Dzilam lagoon

  9. Evolution of an intermittent lagoon-barrier system with rising sea level: observations and projections from the Muni-Pomadze lagoon, Ghana

    NASA Astrophysics Data System (ADS)

    Davies-Vollum, Sian

    2016-04-01

    Intermittently closed lagoon-barrier systems are a transitory environment between land and sea that are influenced by fluvial and marine processes as well as human activities. Fluvial processes dominate most of the time, when the barrier is closed. However, when the barrier is breached an ephemeral connection between the lagoon and the ocean develops and estuarine-like conditions ensue. As sea level rises, the evolution of these systems from intermittently closed to open is dependent on multiple processes including barrier breaching, fragmentation and overwashing. Human intervention, often to prevent flooding, also has an impact. The Muni-Pomadze lagoon in central Ghana is a small, intermittently closed lagoon-barrier system that supports a local fishing community. A beach-barrier separates the lagoon from the ocean, impounding river water and sediment behind it for most of the year. At the end of a rainy season the barrier may be breached, either naturally or by human intervention to prevent flooding of dwellings on the barrier. Field observation, digital mapping and GIS analysis of the shoreline has enabled an understanding of how the barrier is evolving with rising sea level. The shore face of the barrier has shifted landwards with an average retreat rate of 0.22 m/yr. Small washover fans, developed at low points along the lagoon side of the barrier have developed. However, aerial photos reveal that these fans have remained stable since 1972 (earliest available air photos). The small size and stability of these fans suggests that overwashing is not an important factor in the evolution of the barrier and that the barrier is being eroded rather not moving landward. Erosion is particularly prevalent at the breach end of the barrier with an average rate of loss of 3 metres per year and palm trees that were providing stability to the barrier have been washed away. Unconsolidated sands forming a transient, spit-like feature have replaced the stable barrier, which

  10. Sequencing batch reactor performance treating PAH contaminated lagoon sediments.

    PubMed

    Giordano, Andrea; Stante, Loredana; Pirozzi, Francesco; Cesaro, Raffaele; Bortone, Giuseppe

    2005-03-17

    The applicability of sediment slurry sequencing batch reactors (SBR) to treat Venice lagoon sediments contaminated by polycyclic aromatic hydrocarbons (PAHs) was investigated, carrying out experimental tests. The slurry, obtained mixing tap water and contaminated sediments with 17.1 mg kg(-1) TS total PAHs content, was loaded to a 8l lab-scale completely stirred reactor, operated as a sequencing batch reactor. Oxygen uptake rate exerted by the slurry, measured by means of a DO-stat titrator, was used to monitor the in-reactor biological activity and to select the optimal operating conditions for the sediment slurry SBR. The PAHs removal efficiency was evaluated in different operating conditions, obtained changing the hydraulic retention time (HRT) of the lab-scale reactor and adding an external carbon source to the slurry. HRT values used during the experiments are 98, 70 and 35 days, whereas the carbon source was added in order to evaluate its effect on the biological activity. The results have shown a stable degradation of PAHs, with a removal efficiency close to 55%, not dependent on the addition of carbon source and the tested HRTs.

  11. The Maastrichtian flora of the Amaam Lagoon area (Northeastern Russia)

    NASA Astrophysics Data System (ADS)

    Moiseeva, M. G.

    2012-12-01

    The Maastrichtian Koryak flora from the Amaam Lagoon area is comprehensively studied with reference to available data on the stratigraphy of the study area and age assessment of the flora-bearing deposits. In the Koryak flora 32 species of plant fossils are identified and systematically described in the work. The established traits of the Koryak floristic assemblage are used to correlate it with the other assemblages close in age from different localities of Northeastern RNortheastern Russiaussia and Alaska. The results of correlation and taxonomic revision of plant fossils from the upper part of the Prince Creek Formation, Northern Alaska show that in the Anadyr-Koryak and Northern Alaska circum-Pacific regions the Koryak stage of flora development and the respective phytostratigraphic horizon (upper Maastrichtian-Selandian), of key significance for interregional correlation of continental deposits, are distinguishable. Floristic changes recorded in the northern circum-Pacific regions across the Cretaceous-Paleogene boundary suggest that the evolution of vegetation was gradual, controlled by climatic change, evolutionary factors and plant migration. These results are inconsistent with the postulated global significance of the ecological crisis at that time.

  12. Advection within shallow pore waters of a coastal lagoon, Florida

    USGS Publications Warehouse

    Cable, J.E.; Martin, Jonathan B.; Swarzenski, Peter W.; Lindenberg, Mary K.; Steward, Joel

    2004-01-01

    Ground water sources can be a significant portion of a local water budget in estuarine environments, particularly in areas with high recharge rates, transmissive aquifers, and permeable marine sediments. However, field measurements of ground water discharge are often incongruent with ground water flow modeling results, leaving many scientists unsure which estimates are accurate. In this study, we find that both measurements and model results are reasonable. The difference between estimates apparently results from the sources of water being measured and not the techniques themselves. In two locations in the Indian River Lagoon estuarine system, we found seepage meter rates similar to rates calculated from the geochemical tracers 222Rn and 226Ra. Ground water discharge rates ranged from 4 to 9 cm/d using seepage meters and 3 to 20 cm/d using 222Rn and 226Ra. In contrast, in comparisons to other studies where finite element ground water flow modeling was used, much lower ground water discharge rates of ∼0.05 to 0.15 cm/d were estimated. These low rates probably represent discharge of meteoric ground water from land-recharged aquifers, while the much higher rates measured with seepage meters, 222Rn, and 226Ra likely include an additional source of surface waters that regularly flush shallow (< 1 m depth) sediments. This resultant total flow of mixed land-recharged water and recirculated surface waters contributes to the total biogeochemical loading in this shallow estuarine environment.

  13. Distribution and ecological relevance of fine sediments in organic-enriched lagoons: the case study of the Cabras lagoon (Sardinia, Italy).

    PubMed

    Magni, P; De Falco, G; Como, S; Casu, D; Floris, A; Petrov, A N; Castelli, A; Perilli, A

    2008-03-01

    In organic-enriched sedimentary systems, like many Mediterranean coastal lagoons, a detailed analysis of sediment grain size composition and partitioning within the muds is crucial to investigate sedimentological trends related to both hydrodynamic energy and basin morphology. In these systems, sediment dynamics are particularly important because the partitioning and transport of fine sediments can strongly influence the redistribution and accumulation of large amounts of organic matter, and consequently the distribution of benthic assemblages and the trophic status and functioning of a lagoon. Nevertheless, studies on benthic-sediment relationships have been based mainly on a rather coarse analysis of sediment grain size features. In muddy systems, however, this approach may impede a proper evaluation of the relationships and effects of the distribution of fine sediment and organic matter on the biotic benthic components. Here we show that the distribution of sedimentary organic matter (OM) and total organic carbon (TOC) in the Cabras lagoon (Sardinia, Italy) can be explained (i.e., predicted) as a function of a nonlinear increase in the amount of the cohesive fraction of sediments (< or = 8 microm grain size particles) and that this fraction strongly influences the structure, composition and distribution of macrobenthic assemblages. Even in such a homogeneously muddy system, characterized by "naturally" occurring impoverished communities, impaired benthic assemblages were found at < or = 8 microm, OM, TOC contents of about 77%, 11% and 3.5%, respectively. A review of studies conducted in Mediterranean coastal lagoons highlighted a lack of direct integrated analysis of sediment features and the biotic components. We suggest that, especially in organic-enriched coastal lagoons, monitoring programs should primarily investigate and consider the cohesive fraction of sediments in order to allow a better assessment of benthic-sediment relationships and ecological

  14. Effectiveness of porous covers for control of ammonia, reduced sulfur compounds, total hydrocarbons, selected volatile organic compounds, and odor from hog manure storage lagoons.

    PubMed

    Regmi, Shekhar; Ongwandee, Maneerat; Morrison, Glenn; Fitch, Mark; Surampalli, Rao

    2007-06-01

    Anaerobic lagoons are a major source of odor at concentrated animal feeding operations. Seven different kinds of artificial (geotextile and polyethylene foam) and natural (straw and redwood) permeable lagoon covers were evaluated for their potential to reduce odorous emissions generated by anaerobic waste lagoons. A novel floating sampling raft was constructed and used to simultaneously evaluate the effectiveness of lagoon covers on an operating swine waste lagoon. The air collected from the raft was evaluated for odor, total reduced sulfur (TRS) compounds, ammonia, total hydrocarbons, dimethyldisulfide, and trimethylamine. The emission rates from the lagoon were highly variable both temporally and spatially. All of the lagoon covers substantially reduced TRS emissions and odor. Geotextile fabric and a recycled foam cover exhibited the greatest reduction in total hydrocarbon emissions; natural covers were less effective. Because of consistently low emission rates of ammonia, no statistically significant reduction of ammonia emissions were observed from any of the lagoon covers.

  15. [Species and size composition of fishes in Barra de Navidad lagoon, Mexican central Pacific].

    PubMed

    González-Sansón, Gaspar; Aguilar-Betancourt, Consuelo; Kosonoy-Aceves, Daniel; Lucano-Ramírez, Gabriela; Ruiz-Ramírez, Salvador; Flores-Ortega, Juan Ramón; Hinojosa-Larios, Angel; de Asís Silva-Bátiz, Francisco

    2014-03-01

    Coastal lagoons are considered important nursery areas for many coastal fishes. Barra de Navidad coastal lagoon (3.76km2) is important for local economy as it supports tourism development and artisanal fisheries. However, the role of this lagoon in the dynamics of coastal fish populations is scarcely known. Thus, the objectives of this research were: to characterize the water of the lagoon and related weather conditions, to develop a systematic list of the ichthyofauna, and to estimate the proportion of juveniles in the total number of individuals captured of most abundant species. Water and fish samples were collected between March 2011 and February 2012. Physical and chemical variables were measured in rainy and dry seasons. Several fishing gears were used including a cast net, beach purse seine and gillnets of four different mesh sizes. Our results showed that the lagoon is most of the time euhaline (salinity 30-40ups), although it can be mixopolyhaline (salinity 18-30ups) during short periods. Chlorophyll and nutrients concentrations suggested eutrophication in the lagoon. Mean water temperature changed seasonally from 24.9 degrees C (April, high tide) to 31.4 degrees C (October, low tide). Considering ichthyofauna species, a total of 36 448 individuals of 92 species were collected, 31 of them adding up to 95% of the total of individuals caught. Dominant species were Anchoa spp. (44.6%), Diapterus peruvianus (10.5%), Eucinostomus currani (8.1%), Cetengraulis mysticetus (7.8%), Mugil curema (5.2%) and Opisthonema libertate (4.5%). The lagoon is an important juvenile habitat for 22 of the 31 most abundant species. These included several species of commercial importance such as snappers (Lutjanus argentiventris, L. colorado and L. novemfasciatus), snook (Centropomus nigrescens) and white mullet (Mugil curema). Other four species seem to use the lagoon mainly as adults. This paper is the first contribution on the composition of estuarine ichthyofauna in Jalisco

  16. Modelling water discharges and nutrient inputs into a Mediterranean lagoon (Thau, France). Impact on phytoplankton production.

    NASA Astrophysics Data System (ADS)

    Plus, M.; La Jeunesse, I.; Bouraoui, F.

    2003-04-01

    The lagoon of Thau (French Mediterranean coast), is a large (75 km2) and rather deep coastal lagoon (mean depth 4 m), connected to the sea by its two extremities (residence time: about 3 months). Besides its ecological interest as a breeding and transit zone for some sea fish species, the lagoon has a notable economic importance due to shellfish cultivation with an annual oyster production of about 15 000 tons. This considerable production depends to a large extent on nutrient inputs into the ecosystem, supplied mainly from fresh water. The catchment area is about 280 Km2, including agriculture (mainly vineyards), industrial activities and urban waste. Due to the low water renewal and to the intensive shellfish farming activities the Thau lagoon is particularly sensitive to any modification in watershed outputs. The aim of this study is to assess the impact of watershed outputs on the lagoon ecosystem. The Soil and Water Assessment Tool (SWAT model) has been applied to the Thau lagoon catchment area in order to simulate water discharges and nutrients (ammonium, nitrate, and phosphates) inputs into the lagoon on a 10 years period (1989-1999). The model has been calibrated and validated using measured data available for the two main rivers of the watershed, representing about 50% of total freshwater inputs. The model predictions compared favourably with the measurements concerning water quantity as well as major water quality determinants (ammonium, nitrate, phosphates, and suspended matter). Then, several scenarios (e. g. changes in agricultural practices) have been run and the simulated results were used as forcing variables in a lagoon ecosystem model, previously developed for Thau. The latter is a three-dimensional model coupling both hydrodynamical and biological processes. The following state variables are simulated in the model biological part: ammonia, nitrates, phytoplankton, zooplankton, detritus, oyster biodeposits and oxygen. In addition to the inputs

  17. Biodiversity patterns of macrophyte and macroinvertebrate communities in two lagoons of Western Greece.

    NASA Astrophysics Data System (ADS)

    Fyttis, G.; Reizopoulou, S.; Papastergiadou, E.

    2012-04-01

    Aquatic macrophytes and benthic macroinvertebrates were studied seasonally (Spring, Autumn, Summer) between the years 2009 - 2011 in two coastal lagoons (Kotychi and Prokopos) located in Peloponnese, Greece, in order to investigate spatial and temporal biodiversity trends related to hydrological processes (degree of confinement, nitrates, phosphates, chl-a, total suspended materials, light irradiance, pH, salinity, temperature and dissolved oxygen). Kotychi lagoon presents a better communication with the sea, while Prokopos has a high degree of confinement. Both ecosystems seasonally receive freshwater input from streams. The submerged aquatic macrophytes constituted a major component of the ecosystems studied. In total, 22 taxa of aquatic macrophytes (angiosperms and macroalgae), 16 taxa for Kotychi (2 Rhodophyta, 8 Chlorophyta, 5 Magnoliophyta, 1 Streptophyta) and 14 taxa for Prokopos (1 Rhodophyta, 5 Chlorophyta, 5 Magnoliophyta, 3 Streptophyta) were found. Ruppia cirrhosa, and Potamogeton pectinatus were dominant in both lagoons. Kotychi lagoon was also dominated by Zostera noltii and Prokopos by Zannichellia pallustris ssp. pedicellata, while the biomass of aquatic species peaked during the summer periods, in both lagoons. The total number of macroinvertebrates found in the lagoons was 28 taxa for Kotychi and 19 for Prokopos. Chironomidae were dominant in both lagoons, while Kotychi was also dominated by Lekanesphaera monodi and Monocorophium insidiosum, and Prokopos by Ostracoda and Lekanesphaera monodi. Benthic diversity ranged from 1.33 to 2.57 in Kotychi and from 0.67 to 2.48 in Prokopos. Species richness, diversity, and abundance of benthic macroinvertebrates were strongly related to aquatic vegetation and to the degree of communication with the marine environment. Moreover, species richness and abundance of both macrophytes and macroinvertebrates were mainly dependent on depth, temperature, pH and concentration of total suspended materials (TSM). Results

  18. Review of solutions for 3D hydrodynamic modeling applied to aquaculture in South Pacific atoll lagoons.

    PubMed

    Andréfouët, S; Ouillon, S; Brinkman, R; Falter, J; Douillet, P; Wolk, F; Smith, R; Garen, P; Martinez, E; Laurent, V; Lo, C; Remoissenet, G; Scourzic, B; Gilbert, A; Deleersnijder, E; Steinberg, C; Choukroun, S; Buestel, D

    2006-10-01

    A workshop organized in French Polynesia in November 2004 allowed reviewing the current methods to model the three-dimensional hydrodynamic circulation in semi-enclosed atoll lagoons for aquaculture applications. Mollusk (e.g. pearl oyster, clam) aquaculture is a major source of income for South Pacific countries such as French Polynesia or Cook Islands. This aquaculture now requires a better understanding of circulation patterns to improve the spatial use of the lagoons, especially to define the best area to set larvae collectors. The pelagic larval duration of the relevant species (<20 days) and the size of the semi-closed lagoons (few hundreds of km2) drive the specifications of the model in terms of the spatial and temporal scale. It is considered that, in contrast with fish, mollusk larvae movements are limited and that their cycle occurs completely in the lagoon, without an oceanic stage. Atolls where aquaculture is productive are generally well-bounded, or semi-closed, without significant large and deep openings to the ocean. Nevertheless part of the lagoon circulation is driven by oceanic water inputs through the rim, ocean swells, tides and winds. Therefore, boundary conditions of the lagoon system are defined by the spatial structure of a very shallow rim (exposition and number of hoas), the deep ocean swell climate, tides and wind regimes. To obtain a realistic 3D numerical model of lagoon circulation with adequate forcing, it is thus necessary to connect in an interdisciplinary way a variety of methods (models, remote sensing and in situ data collection) to accurately represent the different components of the lagoon system and its specific boundary conditions. We review here the current methods and tools used to address these different components for a hypothetical atoll of the Tuamotu Archipelago (French Polynesia), representative of the semi-closed lagoons of the South Pacific Ocean. We hope this paper will serve as a guide for similar studies

  19. Characterizing ammonia and hydrogen sulfide emissions from a swine waste treatment lagoon in North Carolina

    NASA Astrophysics Data System (ADS)

    Blunden, Jessica; Aneja, Viney P.

    Emissions of atmospheric ammonia-nitrogen (NH 3-N, where NH 3-N=(14/17)NH 3) and hydrogen sulfide (H 2S) from a commercial anaerobic swine waste treatment lagoon (17,150 m 2 at normal liquid level) were measured over a 1-year period. Continuous simultaneous measurements were made at the lagoon using a dynamic flow-through chamber system for ˜1 week during four seasons, October-November 2004 (fall), February 2005 (winter), April 2005 (spring), and June 2005 (summer) in an effort to examine diurnal and seasonal variability, and the respective relationships of NH 3-N and H 2S emissions to lagoon physicochemical properties. Continuously measured lagoon physicochemical parameters include lagoon surface temperature and lagoon pH. Aqueous lagoon samples were collected daily and analyzed for total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN), and total sulfide concentration. TKN, TAN, and sulfide concentrations ranged from 400-650, 360-590, and 0.1-13.0 mg L -1, respectively. For NH 3-N, the largest fluxes were observed during the summer (>4200 μg N m -2 min -1). During the fall and spring, average NH 3-N fluxes were 1634±505 and >2495 μg N m -2 min -1, respectively. The lowest fluxes were observed during the winter where average flux values were 1290±246 μg N m -2 min -1. Fluxes for H 2S were negligible during the winter season. Average fluxes increased during the fall (0.3±0.1 μg m -2 min -1) and spring (0.5±1.0 μg m -2 min -1), and highest flux values were observed during the summer (5.3±3.2 μg m -2 min -1). The seasonal NH 3-N and H 2S emission factors ranged from ˜10 to ˜40 kg N AU -1 yr -1 (1 AU=500 kg live animal weight) and ˜0 to ˜0.05 kg H 2S AU -1 yr -1, respectively. Generally, the lagoon emissions for H 2S were ˜3-4 orders of magnitude less than NH 3-N. The gas fluxes were related to various physicochemical parameters including the pH and near-surface temperature of the lagoon, and the aqueous concentration of the respective gas.

  20. The Finuda Experiment at DAΦNE

    NASA Astrophysics Data System (ADS)

    Lucherini, V.

    The FINUDA (FIsica NUcleare a DAΦNE) experiment was built in order to study the interactions of stopped K- on nuclei, with emphasis on Hypernuclear spectroscopy and Hypernuclei decays. Due to the nice performances of the spectrometer, it proved also suited to study, more generally, final states with several particles and able to recostruct secondary vertices, hence greatly enlarging the physical topics that could be addressed.

  1. The Finuda Experiment at DAΦNE

    NASA Astrophysics Data System (ADS)

    Lucherini, V.

    2010-10-01

    The FINUDA (FIsica NUcleare a DAΦNE) experiment was built in order to study the interactions of stopped K- on nuclei, with emphasis on Hypernuclear spectroscopy and Hypernuclei decays. Due to the nice performances of the spectrometer, it proved also suited to study, more generally, final states with several particles and able to recostruct secondary vertices, hence greatly enlarging the physical topics that could be addressed.

  2. Status of KM3NeT

    NASA Astrophysics Data System (ADS)

    Riccobene, G.

    2016-07-01

    The recent observation of cosmic neutrinos by IceCube has pushed the quest towards the identification of cosmic sources of high-energy particles. The KM3NeT Collaboration is now ready to launch the massive construction of detection units to be installed in deep sea to build a km-cubic size neutrino telescope. The main elements of the detector, the status of the project and the expected perfomances are briefly reported.

  3. CLIPS on the NeXT computer

    NASA Technical Reports Server (NTRS)

    Charnock, Elizabeth; Eng, Norman

    1990-01-01

    This paper discusses the integration of CLIPS into a hybrid expert system neural network AI tool for the NeXT computer. The main discussion is devoted to the joining of these two AI paradigms in a mutually beneficial relationship. We conclude that expert systems and neural networks should not be considered as competing AI implementation methods, but rather as complimentary components of a whole.

  4. DOE/NE robotics for advanced reactors

    SciTech Connect

    Not Available

    1991-01-01

    ORNL is continuing to transfer technology under the NE Robotics for Advanced Reactors Program to other programs and institutions. The HELIX computer architecture developed under the NE robotics program are currently being transferred to the University of Florida for control of their Articulated Transporter Manipulator (ATMS or snake) robot prototype. The Modular Integrated Control architecture (MICA), also developed under the NE Robotics Program is currently being utilized by the DOE ER WM Robotics Program to control a long-reach manipulator for use in cleanup of underground storage tanks at Hanford. HELIX and MICA were developed at ORNL in response to the need to integrate software and hardware developed on different computer systems by the university participants. The University of Texas is constructing and assembling the actuator module. Several parts have been re-machined. The Tennessee group has performed a series of experiments to verify the performance of their system for object localization, identification, and manipulation using 3D Geometric models (SOLIDGEM). The Michigan group has completed experiments on the radiation resistance of ultrasonic range sensors (URSs). The Florida team continues to model key features of the ALMR. Drawings have been received from GE providing much greater detail on many structures. These details are being incorporated into the IGRIP model of the ALMR. A conceptual design for the Articulated Transporter/Manipulator System (ATMS) has been finalized.

  5. Analysis of Lagoonal Ecosystems in the Po River Delta Associated with Intensive Aquaculture

    NASA Astrophysics Data System (ADS)

    Sorokin, Yu. I.; Sorokin, P. Yu.; Ravagnan, G.

    1999-03-01

    Observations on structure and functioning of coastal lagoon ecosystems experiencing a high level of eutrophication impact were accomplished in three lagoons of Ca'Pisani integrated within an experimental aquaculture enterprise variously fertilized by waste effluents discharged from and intensive fish culture plant. During August and early September an extremely dense bloom of dinoflagellate Alexandrium tamarensewas recorded in these lagoons with the density of phytoplankton up to 190 g m -3of wet biomass, and primary production 2 to 6 mg Cl -1 day -1. The diel dissolved oxygen fluctuations in water column during the bloom reached 15-20 mg O 2 l -1. The wet biomass of bacterioplankton in the lagoons attained 5-9 g m -3. The microzooplankton was dominated by ciliates with biomass 1 to 19 g m -3. The daytime mesozooplankton was dominated by calanoid copepods with a biomass 0·05-0·25 g m -3, while the biomass of the demersal zooplankton at night attained 2 to 14 g m -3. In the lagoon of Ocaro, the phototrophic plankton was dominated by the symbiotic ciliate Mesodinium.The labile sulphides content in the upper layer of the bottom attained over 1 g S dm -3of wet silt. The rate of microbial sulphate reduction was 5-10 mg S dm -3day -1. The data are generalized within the energy balance in these specific anthropogenically transformed pelagic communities.

  6. Wind-driven surficial oxygen transfer and dinitrogen gas emission from treatment lagoons.

    PubMed

    Ro, K S; Hunt, P G; Poach, M E

    2006-01-01

    Surficial oxygen transfer plays an important role, when analyzing the complex biochemical and physical processes responsible for ammonia and dinitrogen gas emission in animal waste treatment lagoons. This paper analyzes if currently known nitrogen biochemical pathways can explain the enigmatic dinitrogen gas emissions recently observed from the treatment lagoons, based on the amount of wind-driven oxygen that can be transferred through the air-water interface. The stoichiometric amounts of the maximum dinitrogen gas production potential per unit mass of O(2) transferred were calculated according to three most likely biochemical pathways for ammonia removal in the treatment lagoons-classical nitrification-denitrification, partial nitrification-denitrification, and partial nitrification-Anammox. Partial nitrification-Anammox pathway would produce the largest N(2) emission, followed by partial nitrification-denitrification pathway, then by classical nitrification-denitrification pathway. In order to estimate stoichiometric amount (i.e., maximum) of N(2) emission from these pathways, we assumed that heterotrophic respiration was substantially inhibited due to high levels of free ammonia prevalent in treatment lagoons. Most observed N(2) emission data were below the maximum N(2) emission potentials by the classical nitrification-denitrification pathway. However, one value of observed N(2) emission was much higher than that could be produced by even the partial nitrification-Anammox pathway. This finding suggests yet unknown biological processes and/or non-biological nitrogen processes such as chemodenitrification may also be important in these treatment lagoons.

  7. Comprehensive assessment of hormones, phytoestrogens, and estrogenic activity in an anaerobic swine waste lagoon

    USGS Publications Warehouse

    Yost, Erin E.; Meyer, Michael T.; Dietze, Julie E.; Meissner, Benjamin M.; Williams, Mike; Worley-Davis, Lynn; Lee, Boknam; Kullman, Seth W.

    2013-01-01

    In this study, the distribution of steroid hormones, phytoestrogens, and estrogenic activity was thoroughly characterized within the anaerobic waste lagoon of a typical commercial swine sow operation. Three independent rounds of sampling were conducted in June 2009, April 2010, and February 2011. Thirty-seven analytes in lagoon slurry and sludge were assessed using LC/MS-MS, and yeast estrogen screen was used to determine estrogenic activity. Of the hormone analytes, steroidal estrogens were more abundant than androgens or progesterone, with estrone being the predominant estrogen species. Conjugated hormones were detected only at low levels. The isoflavone metabolite equol was by far the predominant phytoestrogen species, with daidzein, genistein, formononetin, and coumestrol present at lower levels. Phytoestrogens were often more abundant than steroidal estrogens, but contributed minimally towards total estrogenic activity. Analytes were significantly elevated in the solid phases of the lagoon; although low observed log KOC values suggest enhanced solubility in the aqueous phase, perhaps due to dissolved or colloidal organic carbon. The association with the solid phase, as well as recalcitrance of analytes to anaerobic degradation, results in a markedly elevated load of analytes and estrogenic activity within lagoon sludge. Overall, findings emphasize the importance of adsorption and transformation processes in governing the fate of these compounds in lagoon waste, which is ultimately used for broadcast application as a fertilizer.

  8. Quantification of Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio cholerae in French Mediterranean coastal lagoons.

    PubMed

    Cantet, Franck; Hervio-Heath, Dominique; Caro, Audrey; Le Mennec, Cécile; Monteil, Caroline; Quéméré, Catherine; Jolivet-Gougeon, Anne; Colwell, Rita R; Monfort, Patrick

    2013-10-01

    Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio cholerae are human pathogens. Little is known about these Vibrio spp. in the coastal lagoons of France. The purpose of this study was to investigate their incidence in water, shellfish and sediment of three French Mediterranean coastal lagoons using the most probable number-polymerase chain reaction (MPN-PCR). In summer, the total number of V. parahaemolyticus in water, sediment, mussels and clams collected from the three lagoons varied from 1 to >1.1 × 10³ MPN/l, 0.09 to 1.1 × 10³ MPN/ml, 9 to 210 MPN/g and 1.5 to 2.1 MPN/g, respectively. In winter, all samples except mussels contained V. parahaemolyticus, but at very low concentrations. Pathogenic (tdh- or trh2-positive) V. parahaemolyticus were present in water, sediment and shellfish samples collected from these lagoons. The number of V. vulnificus in water, sediment and shellfish samples ranged from 1 to 1.1 × 10³ MPN/l, 0.07 to 110 MPN/ml and 0.04 to 15 MPN/g, respectively, during summer. V. vulnificus was not detected during winter. V. cholerae was rarely detected in water and sediment during summer. In summary, results of this study highlight the finding that the three human pathogenic Vibrio spp. are present in the lagoons and constitute a potential public health hazard.

  9. Benthic foraminiferal assemblages and trace element contents from the lagoons of Orbetello and Lesina.

    PubMed

    Frontalini, Fabrizio; Coccioni, Rodolfo; Bucci, Carla

    2010-11-01

    The Italian marginal areas of Orbetello and Lesina lagoons have been investigated in order to assess the response of benthic foraminifera to the trace element contents in the sediments. The investigated lagoons are deeply affected by high values of trace elements. The lagoon of Orbetello shows the highest values of Cd, Cu, Ni, Pb, Zn, and Hg, whereas the lagoon of Lesina exhibits the highest values of As. On the basis of the trace element contents, both lagoons can be considered from moderately to strongly polluted. Biotic and abiotic factors have been investigated with multivariate technique of statistical analysis. On the basis of the trace element content, the cluster analysis reveals the occurrence of three main clusters. These natural groupings are also confirmed by the principal component analysis. The comparison of trace element concentration patterns with the Foraminiferal Abnormality Index shows a possible influence of these pollutants on the benthic foraminiferal assemblages. Generally, the highest concentrations of trace elements in the investigated areas are remarkably mirrored by the highest percentages of deformed specimens.

  10. Comprehensive Assessment of Hormones, Phytoestrogens, and Estrogenic Activity in an Anaerobic Swine Waste Lagoon

    PubMed Central

    2013-01-01

    In this study, the distribution of steroid hormones, phytoestrogens, and estrogenic activity was thoroughly characterized within the anaerobic waste lagoon of a typical commercial swine sow operation. Three independent rounds of sampling were conducted in June 2009, April 2010, and February 2011. Thirty-seven analytes in lagoon slurry and sludge were assessed using LC/MS-MS, and yeast estrogen screen was used to determine estrogenic activity. Of the hormone analytes, steroidal estrogens were more abundant than androgens or progesterone, with estrone being the predominant estrogen species. Conjugated hormones were detected only at low levels. The isoflavone metabolite equol was by far the predominant phytoestrogen species, with daidzein, genistein, formononetin, and coumestrol present at lower levels. Phytoestrogens were often more abundant than steroidal estrogens, but contributed minimally toward total estrogenic activity. Analytes were significantly elevated in the solid phases of the lagoon; although low observed log KOC values suggest enhanced solubility in the aqueous phase, perhaps due to dissolved or colloidal organic carbon. The association with the solid phase, as well as recalcitrance of analytes to anaerobic degradation, results in a markedly elevated load of analytes and estrogenic activity within lagoon sludge. Overall, findings emphasize the importance of adsorption and transformation processes in governing the fate of these compounds in lagoon waste, which is ultimately used for broadcast application as a fertilizer. PMID:24144340

  11. Ecophysiological differences of betaproteobacterial populations in two hydrochemically distinct compartments of a subtropical lagoon.

    PubMed

    Alonso, Cecilia; Zeder, Michael; Piccini, Claudia; Conde, Daniel; Pernthaler, Jakob

    2009-04-01

    We studied the population sizes and substrate incorporation patterns of three phylogenetic groups of Betaproteobacteria in a coastal subtropical lagoon that is characterized by a sharp transition from humic freshwater to turbid brackish water. Various cellular processes were addressed by short-term incubations with four radiolabelled compounds and microautoradiographic assessment of substrate incorporation. Group-specific differences in the abundances and the respective physiological state of the three populations were observed upon transfer from the humic-rich compartment to the main body of the lagoon (estimated at 1-2 days). Members of the clade B of Polynucleobacter (PnecB) experienced only an insignificant change in cell numbers, but displayed a general metabolic downshift, carbon metabolism (glucose incorporation) being most affected. By contrast, bacteria from the closely related Polynucleobacter C clade (PnecC) clearly differed in total abundances and in the numbers of DNA-synthesizing or glucose incorporating cells. At the same time, PnecC bacteria maintained comparable levels of protein synthesis (leucine uptake) in both lagoon compartments, and the proportion of cells incorporating N-acetylglucosamine was even higher in the main body of the lagoon. Members of the R-BT lineage showed little changes in cell numbers, DNA synthesis and carbon metabolism. Altogether, the observed patterns of substrate metabolism suggest that different bacterial populations in the lagoon undergo specific physiological adjustments in response to changing environmental conditions.

  12. Management strategies to optimise sustainable clam ( Tapes philippinarum) harvests in Barbamarco Lagoon, Italy

    NASA Astrophysics Data System (ADS)

    Spillman, C. M.; Hamilton, D. P.; Imberger, J.

    2009-01-01

    Barbamarco Lagoon is a small lagoon adjoining the Northern Adriatic Sea and is the site of a commercially valuable clam ( Tapes philippinarum) fishery. A three-dimensional (3D) coupled hydrodynamic-ecological model was applied to the lagoon with the objective of assessing impacts on clam food supply, commercial harvests and water quality of different clam rearing strategies, lagoon morphologies and flow regimes. Harvest and net growth to seeding ratios, total harvest value, clearance efficiencies and clam satiety were used to quantify the commercial success of different management strategies, while bottom dissolved oxygen concentrations were used as an indicator of ecosystem health. Increasing exchange with the Northern Adriatic Sea or increasing freshwater inputs into the lagoon improved clam food supply and increased both harvest production and ecosystem health in model simulations of the system. Results indicated that the high spatial and temporal variability of clam production and water quality responses must be considered for a holistic assessment of the outcomes of strategies in the context of ecological and production carrying capacity.

  13. Assessing pollution in a Mediterranean lagoon using acid volatile sulfides and estimations of simultaneously extracted metals.

    PubMed

    Zaaboub, Noureddine; Helali, Mohamed Amine; Martins, Maria Virgínia Alves; Ennouri, Rym; Béjaoui, Béchir; da Silva, Eduardo Ferreira; El Bour, Monia; Aleya, Lotfi

    2016-11-01

    Bizerte Lagoon is a southern Mediterranean semi-enclosed lagoon with a maximum depth of 12 m. After assessing sediment quality, the authors report on the physicochemical characteristics of the lagoon's surface sediment using SEM (simultaneously extracted metals) and AVS (acid volatile sulfides) as proxies. Biogeochemical tools are used to investigate the environmental disturbance at the water-sediment interface by means of SEM and AVS to seek conclusions concerning the study area's pollution status. Results confirm accumulation of trace elements in sediment. The use of the SEM-AVS model with organic matter in sediment (ƒOC) confirms possible bioavailability of accumulated trace elements, especially Zn, in the southern part of the lagoon, with organic matter playing an important role in SEM excess correction to affirm a nontoxic total metal sediment state. Individual trace element toxicity is dependent on the bioavailable fraction of SEMMetal on sediment, as is the influence of lagoon inflow from southern water sources on element bioavailability. Appropriate management strategies are highly recommended to mitigate any potential harmful effects on health from this heavy-metal-based pollution.

  14. Effects of sawdust pollution on the germination of fungal spores in Lagos Lagoon.

    PubMed

    Akpata, T V

    1987-01-01

    Four fungi, Aspergillus flavus, Aspergillus giganteus, Cladosporium oxysporum a and Trichoderma aureoviride, isolated from Lagos Lagoon, were tested for spore germination in aqueous sawdust extract of different hardwood species (Khaya ivorensis, Mitragyna ciliata and Triplochiton scleroxylon). Extracts of M. ciliata were inhibitory to spore germination especially at higher concentrations. Germ tubes of spores decreased in length with increase in extract concentration for C. oxysporum and T. aureoviride, while Aspergillus species showed increase in length up to a peak at 3% sawdust extract concentration, and thereafter germ tube lengths decreased with increasing concentration. Extracts of T. scleroxylon stimulated the spores and percentage germination increased at higher extract concentrations with no significant difference in germ tube length. Similarly, K. ivorensis had a stimulatory effect on spore germination and length of germ tube, especially at higher extract concentrations. Addition of soluble exogenous carbon and nitrogen sources to sawdust extract enhanced spore germination. Apart from A. flavus, which had only 9% germination, all the spores failed to germinate in lagoon water having 21% salinity. The spores were also inhibited by in lagoon water having 21 per thousand salinity. The spores were also inhibited by various inorganic salts, i.e. CaCl(2), KH(2)PO(4), MgSO(4) and NaCl, present in Lagos Lagoon. The results suggest that sawdust pollution causes enrichment of the lagoon, thereby enhancing spore germination.

  15. Comprehensive assessment of hormones, phytoestrogens, and estrogenic activity in an anaerobic swine waste lagoon.

    PubMed

    Yost, Erin E; Meyer, Michael T; Dietze, Julie E; Meissner, Benjamin M; Worley-Davis, Lynn; Williams, C Michael; Lee, Boknam; Kullman, Seth W

    2013-12-03

    In this study, the distribution of steroid hormones, phytoestrogens, and estrogenic activity was thoroughly characterized within the anaerobic waste lagoon of a typical commercial swine sow operation. Three independent rounds of sampling were conducted in June 2009, April 2010, and February 2011. Thirty-seven analytes in lagoon slurry and sludge were assessed using LC/MS-MS, and yeast estrogen screen was used to determine estrogenic activity. Of the hormone analytes, steroidal estrogens were more abundant than androgens or progesterone, with estrone being the predominant estrogen species. Conjugated hormones were detected only at low levels. The isoflavone metabolite equol was by far the predominant phytoestrogen species, with daidzein, genistein, formononetin, and coumestrol present at lower levels. Phytoestrogens were often more abundant than steroidal estrogens, but contributed minimally toward total estrogenic activity. Analytes were significantly elevated in the solid phases of the lagoon; although low observed log KOC values suggest enhanced solubility in the aqueous phase, perhaps due to dissolved or colloidal organic carbon. The association with the solid phase, as well as recalcitrance of analytes to anaerobic degradation, results in a markedly elevated load of analytes and estrogenic activity within lagoon sludge. Overall, findings emphasize the importance of adsorption and transformation processes in governing the fate of these compounds in lagoon waste, which is ultimately used for broadcast application as a fertilizer.

  16. Daily availability of nutrients and metals in a eutrophic meso-tidal coastal lagoon (Obidos lagoon, Portugal).

    PubMed

    Pereira, Patrícia; de Pablo, Hilda; Carvalho, Susana; Vale, Carlos; Pacheco, Mário

    2010-10-01

    This baseline reports daily variations of physico-chemical parameters, nutrients and metals in water of two sites [eutrophic conditions (BB) versus reference (LL)] in Obidos coastal lagoon (Portugal). Dissolved oxygen in BB varied between 40% saturation levels (night) and 190% (daylight). NH(4)(+), PO(4)(3-) and ratios to Al of Mn, Fe and Pb in suspended particulate matter increased during the period of lower oxygenation, indicating exportation of nutrients and metals from the sediment to water at night. At LL, O(2) values oscillated always around 100%. PO(4)(3-) and Mn/Al ratio at LL were always lower than at BB and no increases were found during the night. The input of PO(4)(3-) and Mn provided from the sediment at BB during the night could surpass the contribution of freshwater discharges. PCA confirmed the separation of most samples from BB and LL. These results pointed to the importance of assessing chemical conditions over day-night cycles.

  17. Using an Integrated Approach to Assess the Sediment Quality of an Mediterranean Lagoon, the Bizerte Lagoon (Tunisia).

    PubMed

    Barhoumi, Badreddine; Elbarhoumi, Anis; Clérandeau, Christelle; Al-Rawabdeh, Abdulla M; Atyaoui, Atef; Touil, Soufiane; Driss, Mohamed Ridha; Cachot, Jérôme

    2016-08-01

    The present study investigates the quality of surface sediments from the Bizerte lagoon (North Tunisia) using an integrated approach including chemical contaminant analysis, bioassays and sediment quality guidelines (SQGs). Sediment samples were collected at 9 sites and analyzed for eight heavy metals (Hg, Cd, Cr, Cu, Pb, Zn, Ni, Fe and Mn). PAHs, PCBs, OCPs were measured previously in the same sediment samples. Our results indicated that the highest concentrations of metals were found near urban areas due to the municipial and industrial wastewater discharges. Sediment pollution assessment was carried out using geoaccumulation index and enrichment factor, which indicate a widespread pollution by Cd, Pb, Ni and Zn in the studied sediments. For bioassays, aqueous and organic extracts were used to assess toxicity and genotoxicity in sediments by using Microtox(®) and SOS Chromotest, respectively. Toxicity levels were compared to metallic and organic pollutants contents. Our results highlight differences in the pattern of responses between the different assays and show no correlation with all the studied contaminants, emphasizing the influence of other contaminants not analyzed in the present study. Based on SQGs, the results of toxicity assessment indicated that adverse effects caused by Ni and Zn would be expected frequently. Nickel was found to have the highest predicted acute toxicity, followed by Zn, Pb, Cd, Cu and Cr. There was no significant relationship between sediment toxicity calculated from heavy metal concentrations (SQG approach) and those measured with bioassays. These findings support the use of integrated approachs for evaluating the environmental risks of sediments.

  18. Sterile Neutrino Searches in MiniBooNE and MicroBooNE

    SciTech Connect

    Ignarra, Christina M.

    2014-09-01

    Tension among recent short baseline neutrino experiments has pointed toward the possible need for the addition of one or more sterile (non-interacting) neutrino states into the existing neutrino oscillation framework. This thesis first presents the motivation for sterile neutrino models by describing the short-baseline anomalies that can be addressed with them. This is followed by a discussion of the phenomenology of these models. The MiniBooNE experiment and results are then described in detail, particularly the most recent antineutrino analysis. This will be followed by a discussion of global fits to world data, including the anomalous data sets. Lastly, future experiments will be addressed, especially focusing on the MicroBooNE experiment and light collection studies. In particular, understanding the degradation source of TPB, designing the TPB-coated plates for MicroBooNE and developing lightguide collection systems will be discussed. We find an excess of events in the MiniBooNE antineutrino mode results consistent with the LSND anomaly, but one that has a different energy dependence than the low-energy excess reported in neutrino mode. This disagreement creates tension within global fits which include up to three sterile neutrinos. The low-energy excess will be addressed by the MicroBooNE experiment, which is expected to start taking data in early 2015. Tension among existing experiments calls for additional, more decisive future experiments.

  19. Temporal flux and spatial dynamics of nutrients, fecal indicators, and zoonotic pathogens in anaerobic swine manure lagoon water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine (Sus scrofa domestica) manure management in confined animal feeding operations (CAFOs) in the Mid-South US involves anaerobic lagoons. Lagoon effluent is used to irrigate and fertilize crops. Nutrients and bacteria in effluent have been sporadically characterized, but annual temporal changes...

  20. 75 FR 53299 - Issuance of NPDES General Permits for Wastewater Lagoon Systems Located in Indian Country in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... AGENCY Issuance of NPDES General Permits for Wastewater Lagoon Systems Located in Indian Country in... for wastewater lagoon systems that are located in Indian country in the States of Montana, North Dakota, South Dakota, Utah and Wyoming and the issuance of the NPDES general permit for wastewater...

  1. Improved process model for ammonia volatilization from anaerobic swine lagoons under varying wind speeds and gas bubbling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia volatilization from treatment lagoons varies widely with the lagoon water total ammonia concentration, pH, temperature, suspended solids, atmospheric ammonia concentration above the water surface, and wind speed. Ammonia emissions were estimated with a process-based mechanistic model using a...

  2. International Symposium on Coastal Lagoons. (Bordeaux, France, September 8-14, 1981). Unesco Technical Papers in Marine Science 43.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Div. of Marine Sciences.

    Lagoons and their characteristic coastal bay-mouth bars represent 15 percent of the world coastal zone. They are among the most productive ecosystems in the biosphere, this productivity resulting from the interplay of ocean and continent. An International Symposium on Coastal Lagoons (ISCOL) was held to: assess the state of knowledge in the…

  3. Socio-economic appraisal of fishing community in Pulicat lagoon, south east coast of India: case study.

    PubMed

    Devi, V Vandhana; Krishnaveni, M

    2012-10-01

    Assessment of socio-economic issues of fishing community is an important aspect in framing a strategy for the preservation of eco-systems which leads to sustainable lagoon management. The present investigation analyses the current potential socio-economic status of the fishing community of Pulicat lagoon, the second largest lagoon in India. The socio-economic indicators considered in the study include demography, economic aspects, social aspects and occupation details. The relevant details were collected from 300 fisher folk family by conducting field survey through a well prepared questionnaire in the villages around Pulicat lagoon. The data analysis was done using Statistical Program for Social Sciences (SPSS) to assess the adequacy and precision of the collected data. The important and encouraging socio-economic indicators identified from the field survey for effective lagoon management includes significant presence of younger generation in the region; affinity and self-belongingness of fisher folk towards the lake; better economic status and moderate education level; appreciable fishing income and affinity towards fishing profession. It is emphasized to motivate the fisher folk to improve their work attitude for betterment in economic status. The pertinent lagoon issues, comprising seasonal variation, local fishing issues, pollution from industries, water intake to thermal power plant which directly or indirectly affects the socio-economic status of fishing community, also need much emphasis while proposing sustainable lagoon management system. The information and observation from this study will be very helpful in formulating management policies on the conservation of the Pulicat lagoon ecosystem.

  4. Seasonal and temporal dynamics of macrophytic assemblages and abiotic parameters of coastal lagoons in Western Greece (Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Christia, Chrysoula; Papastergiadou, Eva

    2014-05-01

    Coastal lagoons are considered naturally stressed systems that experience frequent environmental disturbances and fluctuations and they are usually considered as physically controlled ecosystems. Coastal lagoons of Western Greece are representative of four different lagoon types covering a wide range of physiographical and hydrological characteristics. The seasonal differences in the physico-chemical parameters monitored from 2005 to 2007 were reduced in lagoon types (II and III) which characterized by better seawater communication when compared with the chocked lagoon types (Type I and IV). The latter types showed lower salinity values and high nutrient concentrations especially during the wet period. The macrophytic assemblages of coastal lagoons are typically dominated by few genera with great environmental plasticity and salinity competition, among other structuring abiotic variables. The implementation of DCA analysis revealed five distinct macrophytic assemblages in which dominant species were the angiosperms Zostera noltii, Ruppia cirrhosa, Cymodocea nodosa, Potamogeton pectinatus, the charophytes Lamprothamnium papulosum and Chara hispida f. corfuensis, as well as species preferring more marine conditions such as Acanthophora nayadiformis and Cystoseira barbata. The lagoon type IV differs from all other distinguished lagoon types due to the dominance of the species Potamogeton pectinatus and the charophyte Chara hispida f. corfuensis. Regarding the macrophytic assemblages and the univariate variables, important differences were recorded between lagoon types. Chocked lagoons showed low number of species and Shannon diversity index comparing with restricted lagoon types (Types II and III). The multiple linear regression analysis showed that transparency, pH, nitrates, alkalinity and Chl-a could affect the values of the above variables. A decline of angiosperms was referred on a worldwide scale and recorded also in coastal lagoons of Western Greece. A gradual

  5. Assessment of ecological quality of coastal lagoons with a combination of phytobenthic and water quality indices.

    PubMed

    Christia, Chrysoula; Giordani, Gianmarco; Papastergiadou, Eva

    2014-09-15

    Coastal lagoons are ecotones between continents and the sea. Coastal lagoons of Western Greece, subjected to different human pressures, were classified into four different types based on their hydromorphological characteristics and monitored over a three year period for their biotic and abiotic features. Six ecological indices based on water quality parameters (TSI-Chl-a, TSI-TP, TRIX), benthic macrophytes (E-MaQI, EEI-c) and an integrated index TWQI, were applied to assess the ecological status of studied lagoons under real conditions. The trophic status ranged from oligotrophic to hypertrophic according to the index applied. The ecological quality of transitional water ecosystems can be better assessed by using indices based on benthic macrophytes as changes in abundance and diversity of sensitive and tolerant species are the first evidence of incoming eutrophication. The multi-parametric index TWQI can be considered appropriate for the ecological assessment of these ecosystems due to its robustness and the simple application procedure.

  6. The tidal hydrodynamics modeling of the Topolobampo coastal lagoon system and the implications for pollutant dispersion.

    PubMed

    Montaño-Ley, Y; Peraza-Vizcarra, R; Páez-Osuna, F

    2007-05-01

    The tidal hydrodynamics of the Topolobampo coastal lagoon system (Mexico) has been investigated through a modified two dimensional non-linear hydrodynamic finite difference model. The advective and diffusive process acting over a hypothetical pollutant released into the coastal lagoon have also been simulated. Maxima tidal currents (0.85 m/s) were predicted within the main channel, in agree with direct measurements. The direction of the observed fastest currents (SW), also agree quite well with the direction of the strongest tidal current predicted in this investigation, which occur during the ebb when the water of the coastal lagoon is discharged into the Gulf of California. Residual currents (0.01-0.05 m/s) were also predicted. The hypothetical pollutant released within the Topolobampo Harbor would spread to both Ohuira and Topolobampo sections, reaching the inlet after approximately 12 days.

  7. Surface water-groundwater exchange in transitional coastal environments by airborne electromagnetics: The Venice Lagoon example

    NASA Astrophysics Data System (ADS)

    Viezzoli, A.; Tosi, L.; Teatini, P.; Silvestri, S.

    2010-01-01

    A comprehensive investigation of the mixing between salt/fresh surficial water and groundwater in transitional environments is an issue of paramount importance considering the ecological, cultural, and socio-economic relevance of coastal zones. Acquiring information, which can improve the process understanding, is often logistically challenging, and generally expensive and slow in these areas. Here we investigate the capability of airborne electromagnetics (AEM) at the margin of the Venice Lagoon, Italy. The quasi-3D interpretation of the AEM outcome by the spatially constrained inversion (SCI) methodology allows us to accurately distinguish several hydrogeological features down to a depth of about 200 m. For example, the extent of the saltwater intrusion in coastal aquifers and the transition between the upper salt saturated and the underlying fresher sediments below the lagoon bottom are detected. The research highlights the AEM capability to improve the hydrogeological characterization of subsurface processes in worldwide lagoons, wetlands, deltas.

  8. 3D modeling of phytoplankton seasonal variation and nutrient budget in a southern Mediterranean Lagoon.

    PubMed

    Béjaoui, Béchir; Solidoro, Cosimo; Harzallah, Ali; Chevalier, Cristèle; Chapelle, Annie; Zaaboub, Noureddine; Aleya, Lotfi

    2017-01-30

    A 3D coupled physical-biogeochemical model is developed and applied to Bizerte Lagoon (Tunisia), in order to understand and quantitatively assess its hydrobiological functioning and nutrients budget. The biogeochemical module accounts for nitrogen and phosphorus and includes the water column and upper sediment layer. The simulations showed that water circulation and the seasonal patterns of nutrients, phytoplankton and dissolved oxygen were satisfactorily reproduced. Model results indicate that water circulation in the lagoon is driven mainly by tide and wind. Plankton primary production is co-limited by phosphorus and nitrogen, and is highest in the inner part of the lagoon, due to the combined effects of high water residence time and high nutrient inputs from the boundary. However, a sensitivity analysis highlights the importance of exchanges with the Mediterranean Sea in maintaining a high level of productivity. Intensive use of fertilizers in the catchment area has a significant effect on phytoplankton biomass increase.

  9. [The mangrove and others vegetation associations in de Gandoca lagoon, Limón, Costa Rica].

    PubMed

    Coll, M; Fonseca, A C; Cortés, J

    2001-12-01

    Six plant associations were identified at Gandoca Lagoon by photointerpretation and field verification: a) mangroves, b) palm trees swamp, and palm trees with Acrostichum aureum and A. danaefolium, c) mixed palm trees, d) very humid tropical rain forest, and e) tropical beach vegetation. The mangroves cover 12.5 ha surrounding the lagoon and extend 2 km up the Gandoca River. Rhizophora mangle (red mangrove) was the dominant species, with Avicennia germinans (black mangrove), Laguncularia racemosa (white mangrove) and Conocarpus erectus (buttonwood) also present. Moving inland the mangroves grade into a tropical rain forest. Gandoca, the largest and best preserved mangrove of Caribbean Costa Rica, tripled its area from 1976 to 2000. Possible causes include sedimentation and the Limón earthquake, which may have subside the lagoon area.

  10. [Contamination of the Moulay Bouselham Lagoon, Morocco with organochlorine pesticides and nitrates].

    PubMed

    Mehdaoui, O; Venant, A; Fekhaoui, M

    2000-01-01

    In the lagoon system of Moulay Bouselham, on the Atlantic coast of Morocco, drainage bring nutriments and sediments from irrigation systems to the open lagoon. The recent intensification of farming in the surrounding area is the chief cause of this. We studied the chemical pollution of the lagoon, which serves as a nature reserve, by analyzing the nitrate content of the water and the organochlorine pesticide content of the sediment. Comparison with similar ecosystems showed that the sediments were only moderately contaminated. However, the level of nitrates in the water was found to exceed the upper limit of the range of concentrations considered safe for human health in European regulations. The level of nitrate pollution in the area seems to be increasing, whereas organochloride pesticide pollution is on the decrease. The washing out of fertilizer during winter is responsible for much of the nitrate pollution in this season whereas in summer, urban effluents is the chief cause of nitrate contamination.

  11. Metagenomic analysis of microbiota structure evolution in phytoremediation of a swine lagoon wastewater.

    PubMed

    Ye, Jianfeng; Song, Zhaofeng; Wang, Liang; Zhu, Jun

    2016-11-01

    Pytoremediation was studied in this project to treat swine manure lagoon wastewater characteristic of high concentrations of organic carbon, ammonium (N) and phosphorus (P). The impacts of introducing exogenous microalgae Chlorella into the lagoon wastewater on the removal of major nutrients and the transformation of the native wastewater microbiota structure were explored under two phytoremediation modes (shake flask and CO2-air bubbling). The results showed that the inoculation of microalgae could significantly enhance N and P removal. Metagenomic analysis of the native microbiota composition in the wastewater affected by algae inoculation revealed that a substantial population of algicidal bacteria was developed in the shake flask system, while in the CO2-air bubbling system, a niche for more mutualistic bacteria was created, which benefited the maximal algal growth with the simultaneous optimal N and P removal. To our knowledge, this study presents, the first reported case of applying metagenomic approach to a phytoremediation system treating real swine lagoon wastewater.

  12. Controls of Sediment Nitrogen Dynamics in Tropical Coastal Lagoons.

    PubMed

    Enrich-Prast, Alex; Figueiredo, Viviane; Esteves, Francisco de Assis; Nielsen, Lars Peter

    2016-01-01

    Sediment denitrification rates seem to be lower in tropical environments than in temperate environments. Using the isotope pairing technique, we measured actual denitrification rates in the sediment of tropical coastal lagoons. To explain the low denitrification rates observed at all study sites (<5 μmol N2 m-2 h-1), we also evaluated potential oxygen (O2) consumption, potential nitrification, potential denitrification, potential anammox, and estimated dissimilatory nitrate (NO3-) reduction to ammonium (NH4+; DNRA) in the sediment. 15NO3- and 15NH4+ conversion was measured in oxic and anoxic slurries from the sediment surface. Sediment potential O2 consumption was used as a proxy for overall mineralization activity. Actual denitrification rates and different potential nitrogen (N) oxidation and reduction processes were significantly correlated with potential O2 consumption. The contribution of potential nitrification to total O2 consumption decreased from contributing 9% at sites with the lowest sediment mineralization rates to less than 0.1% at sites with the highest rates. NO3- reduction switched completely from potential denitrification to estimated DNRA. Ammonium oxidation and nitrite (NO2-) reduction by potential anammox contributed up to 3% in sediments with the lowest sediment mineralization rates. The majority of these patterns could be explained by variations in the microbial environments from stable and largely oxic conditions at low sediment mineralization sites to more variable conditions and the prevalences of anaerobic microorganisms at high sediment mineralization sites. Furthermore, the presence of algal and microbial mats on the sediment had a significant effect on all studied processes. We propose a theoretical model based on low and high sediment mineralization rates to explain the growth, activity, and distribution of microorganisms carrying out denitrification and DNRA in sediments that can explain the dominance or coexistence of DNRA and

  13. Migration Rate Of Tidal Meanders: Inferences From The Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Finotello, A.; D'Alpaos, A.; Ghinassi, M.; Lanzoni, S.; Marani, M.; Rinaldo, A.

    2015-12-01

    Meandering channels are ubiquitous features of tidal landscapes. However, despite their fundamental role on the eco-morphodynamic evolution of these landscapes, tidal meanders have received less attention when compared to their fluvial counterparts. Improving current understanding of tidal meander migration, a largely-examined topic in fluvial landscapes, is a key step to highlight analogies and differences between tidal and fluvial cases. The migration of about 400 meander bends, belonging to 40 salt-marsh channels in the Northern Venice Lagoon (Italy), from 1968 to nowadays, has been investigated by means of both a classical method in fluvial frameworks and new procedure. Similarities with fluvial meanders occur, although important difference also emerge. Meanders cutting through the San Felice marsh follow the relationship between cartesian length and channel width, typical of meanders developed within different settings. However, meander migration rates proved to be smaller than those characterizing fluvial meanders. Indeed, the analysis of meander migration suggests a mean migration rate of about 0.10 m/year, consistent with the few data available in the literature. As for the fluvial case, the maximum-potential migration rate (i.e. the envelope curve of the relationship between migration rate and bend radius, both divided by channel width) reaches a maximum for radius-over-width ratio included between 2 and 3, regardless of the considered method. Nevertheless, the new-proposed method allows us to provide a more objective and continuous characterization. By using this new procedure, the channel curvature has finally been Fourier-analyzed, confirming the importance of even harmonics along the curvature spectrum. A correlation between migration rates and dominant harmonics seems to drive the evolution of tidal meanders and might represent a key-feature to distinguish them from their fluvial counterparts.

  14. Tidal Meander Migration: a Case Study from the Venice Lagoon

    NASA Astrophysics Data System (ADS)

    D'Alpaos, A.; Ghinassi, M.; Bellucci, L. G.; Marani, M.

    2014-12-01

    Meandering patterns are universal features of tidal landscapes which exert a great influence on the dynamics of tidal channel networks and on the stratigraphy of intertidal platforms. Despite their importance in landscape evolution and their ubiquity, tidal meanders have received less attention when compared to their fluvial counterparts. Quite a few studies, in fact, have focused on the morphodynamic evolution of tidal meanders, together with their planimetric shape and morphometric characteristics. To improve current understanding of tidal meander migration and its possible stratigraphic implications, we have analyzed a sequence of aerial photographs (from 1938 to present day) for a 20 m in diameter, abandoned tidal meander in the Venice Lagoon, and have carried out high-resolution sedimentological and chronostratigraphical analyses of channel deposits. Aerial photographs before and after the cutoff event have been used to infer a minimum velocity of migration. Well-cores have also been collected along a transect crossing through the neck zone in order to evaluate changes in grain size, sedimentation rates across the cutoff event, and gain further insight into the velocity of migration of meander bends. Spatial distribution of sedimentary facies (pointbar sand, oxbowlake and saltmarsh mud), grain size analyses, and 210 Pb and 137Cs chronometers highlighted that meander cutoff occurred progressively around 60 years ago with a velocity of migration of about 0.5m/year. The effectiveness of the methods and the high spatial and temporal resolution of the data call for further investigations and analyses of the type proposed herein, furthermore highlighting the potentiality of the study area as modern analogue for ancient tidal deposits.

  15. Controls of Sediment Nitrogen Dynamics in Tropical Coastal Lagoons

    PubMed Central

    Enrich-Prast, Alex; Figueiredo, Viviane; Esteves, Francisco de Assis; Nielsen, Lars Peter

    2016-01-01

    Sediment denitrification rates seem to be lower in tropical environments than in temperate environments. Using the isotope pairing technique, we measured actual denitrification rates in the sediment of tropical coastal lagoons. To explain the low denitrification rates observed at all study sites (<5 μmol N2 m-2 h-1), we also evaluated potential oxygen (O2) consumption, potential nitrification, potential denitrification, potential anammox, and estimated dissimilatory nitrate (NO3-) reduction to ammonium (NH4+; DNRA) in the sediment. 15NO3- and 15NH4+ conversion was measured in oxic and anoxic slurries from the sediment surface. Sediment potential O2 consumption was used as a proxy for overall mineralization activity. Actual denitrification rates and different potential nitrogen (N) oxidation and reduction processes were significantly correlated with potential O2 consumption. The contribution of potential nitrification to total O2 consumption decreased from contributing 9% at sites with the lowest sediment mineralization rates to less than 0.1% at sites with the highest rates. NO3- reduction switched completely from potential denitrification to estimated DNRA. Ammonium oxidation and nitrite (NO2-) reduction by potential anammox contributed up to 3% in sediments with the lowest sediment mineralization rates. The majority of these patterns could be explained by variations in the microbial environments from stable and largely oxic conditions at low sediment mineralization sites to more variable conditions and the prevalences of anaerobic microorganisms at high sediment mineralization sites. Furthermore, the presence of algal and microbial mats on the sediment had a significant effect on all studied processes. We propose a theoretical model based on low and high sediment mineralization rates to explain the growth, activity, and distribution of microorganisms carrying out denitrification and DNRA in sediments that can explain the dominance or coexistence of DNRA and

  16. Sediment characteristics and water quality in the two hyper-saline lagoons along the Red Sea coast of Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Rasul, Najeeb; Al-Farawati, Radwan; Al-Harbi, Omer; Naser Qutub, Abdul

    2013-04-01

    The two hyper-saline Shoaiba lagoons, Khawr ash Shaibah al Masdudah (northern lagoon) and Khawr ash Shaibah al Maftuhah (southern lagoon) have a unique environmental set-up because no rivers or wadis flow into the lagoons and therefore detrital material to the lagoons is lacking and most of the sediments are indigenous carbonates. The biogenic material is mostly derived from coral debris, coralline algae and molluscs abundant in gravel and sand size fractions. The evaporite deposits from the adjoining sabkhas are transported to the lagoon during tidal cycles. Carbonate is abundant in the form of aragonite and High Mg-calcite indicating carbonate to be recent and formed under shallow water conditions. In general, the sediments are the result of the mechanical breakdown of molluscs and coral reefs by either human activity or by coral boring marine organisms and physical processes such as tidal and wind generated currents. Strong currents dominate only the deeper part at the entrance of the lagoons that causes the winnowing of the finer sediments, and its transportation during flooding and ebbing. Shallow depths averaging 3 m, wind and tidal stirring are the main forces preventing the lagoons from developing stratification resulting in a well-mixed body of water. The shallow depth of the lagoons keep the turbidity levels higher, whereas salinity as high as 52 ‰ and water temperature as high as 38 °C helps in the formation of halite at the periphery. The cyclical inundation of sabkhas by a thin sheet of water during tidal cycles is important in understanding the ecological consequence. Mangrove stands in the lagoons act as a source of nutrients to the flora and fauna inhabiting the lagoons. The configurations of the mouth of the lagoons influence the tidal currents, including the sediment and water movement. The tidal current is enhanced as it enters the lagoons, in response to the funneling effect caused by the narrow channel. The current diffuses as the entrance

  17. Amount and type of derelict gear from the declining black pearl oyster aquaculture in Ahe atoll lagoon, French Polynesia.

    PubMed

    Andréfouët, Serge; Thomas, Yoann; Lo, Cedrik

    2014-06-15

    Pearl oyster aquaculture is a major activity in French Polynesia atoll lagoons. After the economic decline that characterized the last decade, concerns recently rose about discarded installations and materials that supported aquaculture practices and by facilities abandoned after they had to close their activities. In May 2013, a first inventory of the type and amount of pearl farms derelict gear (PFDG) was achieved on 47 sites in Ahe lagoon. Surveys were conducted within and outside the boundaries of aquaculture concessions. Twenty types of PFDG littered the lagoon floor and the water column. The most impacted areas were near abandoned grafting houses with up to nine types of PFDG. Forty-five percent of the sites were impacted, including outside concessions. While management authorities are fully aware of the problem, this first assessment is a wake-up call to stimulate the cleaning of lagoons, enhance awareness among farmers, and identify potential ecological consequences on lagoon ecosystems.

  18. Dissolved Copper, Nickel and Lead in Tampamachoco Lagoon and Tuxpan River Estuary in the SW Gulf of Mexico.

    PubMed

    Garduño Ruiz, E P; Rosales Hoz, L; Carranza Edwards, A

    2016-10-01

    In order to estimate the effects of a thermal power plant, physicochemical parameters and the concentrations of copper, nickel and lead were evaluated in water from both Tampamachoco Lagoon and the estuary of the Tuxpan River. Average salinities were 33.66 ups in the lagoon area, 32.77 ups in the channel that joins the lagoon and the river, and 24.74 ups in the river estuary. Total average metal concentrations were 21.95 for Cu, 29.67 for Ni and 4.31 µ/L for Pb. Sampling point 1 and samples from the bottom water of the lagoon present the highest salinities and concentrations of suspended matter, TOC, Cu, Ni and Pb.These high values may be associated with the infiltration of sea water either from plant operation or from the channel that connects the lagoon with the sea.

  19. Masses and Charge Radii of {sup 17-22}Ne and the Two-Proton-Halo Candidate {sup 17}Ne

    SciTech Connect

    Geithner, W.; Kappertz, S.; Keim, M.; Neugart, R.; Wilbert, S.; Neff, T.; Feldmeier, H.; Herfurth, F.; Yazidjian, C.; Audi, G.; Guenaut, C.; Lunney, D.; Blaum, K.; George, S.; Delahaye, P.; Kellerbauer, A.; Kowalska, M.; Herlert, A.; Kluge, H.-J.; Lievens, P.

    2008-12-19

    High-precision mass and charge radius measurements on {sup 17-22}Ne, including the proton-halo candidate {sup 17}Ne, have been performed with Penning trap mass spectrometry and collinear laser spectroscopy. The {sup 17}Ne mass uncertainty is improved by factor 50, and the charge radii of {sup 17-19}Ne are determined for the first time. The fermionic molecular dynamics model explains the pronounced changes in the ground-state structure. It attributes the large charge radius of {sup 17}Ne to an extended proton configuration with an s{sup 2} component of about 40%. In {sup 18}Ne the smaller radius is due to a significantly smaller s{sup 2} component. The radii increase again for {sup 19-22}Ne due to cluster admixtures.

  20. Tidal dynamics in a changing lagoon: Flooding or not flooding the marginal regions

    NASA Astrophysics Data System (ADS)

    Lopes, Carina L.; Dias, João M.

    2015-12-01

    Coastal lagoons are low-lying systems under permanent changes motivated by natural and anthropogenic factors. Ria de Aveiro is such an example with its margins currently threatened by the advance of the lagoonal waters recorded during the last decades. This work aims to study the tidal modifications found between 1987 and 2012 in this lagoon, motivated by the main channels deepening which induce higher inland tidal levels. Additionally it aims to study the impact that protective walls designed to protect the margins against flooding may have in those modifications under sea level rise predictions. The hydrodynamic model ELCIRC previously calibrated for Ria de Aveiro was used and tidal asymmetry, tidal ellipses and residual currents were analyzed for different scenarios, considering the mean sea level rise predicted for 2100 and the implementation of probable flood protection walls. Results evidenced that lagoon dominance remained unchanged between 1987 and 2012, but distortion decreased/increased in the deeper/shallower channels. The same trend was found under mean sea level rise conditions. Tidal currents increased over this period inducing an amplification of the water properties exchange within the lagoon, which will be stronger under mean sea level rise conditions. The deviations between scenarios with or without flood protection walls can achieve 60% for the tidal distortion and residual currents and 20% for the tidal currents, highlighting that tidal properties are extremely sensitive to the lagoon geometry. In summary, the development of numerical modelling applications dedicated to study the influence of mean sea level rise on coastal low-lying systems subjected to human influence should include structural measures designed for flood defence in order to accurately predict changes in the local tidal properties.

  1. Biotic variation in coastal water bodies in Sussex, England: Implications for saline lagoons

    NASA Astrophysics Data System (ADS)

    Joyce, Chris B.; Vina-Herbon, Cristina; Metcalfe, Daniel J.

    2005-12-01

    Coastal water bodies are a heterogeneous resource typified by high spatial and temporal variability and threatened by anthropogenic impacts. This includes saline lagoons, which support a specialist biota and are a priority habitat for nature conservation. This paper describes the biotic variation in coastal water bodies in Sussex, England, in order to characterise the distinctiveness of the saline lagoon community and elucidate environmental factors that determine its distribution. Twenty-eight coastal water bodies were surveyed for their aquatic flora and invertebrate fauna and a suite of exploratory environmental variables compiled. Ordination and cluster analyses were used to examine patterns in community composition and relate these to environmental parameters. Biotic variation in the coastal water body resource was high. Salinity was the main environmental parameter explaining the regional distribution of taxa; freshwater and saline assemblages were evident and related to sea water ingress. Freshwater sites were indicated by the plant Myriophyllum spicatum and gastropod mollusc Lymnaea peregra, while more saline communities supported marine and brackish water taxa, notably a range of chlorophytic algae and the bivalve mollusc Cerastoderma glaucum. Site community differences were also related to bank slope and parameters describing habitat heterogeneity. A saline lagoon community was discerned within the matrix of biotic variation consisting of specialist lagoonal species with associated typically euryhaline taxa. For fauna, the latter were the molluscs Abra tenuis and Hydrobia ulvae, and the crustaceans Corophium volutator and Palaemonetes varians, and for flora they were the algae Ulva lactuca, Chaetomorpha mediterranea, Cladophora spp. and Enteromorpha intestinalis. One non-native polychaete species, Ficopomatus enigmaticus, also strongly influenced community structure within the lagoonal resource. The community was not well defined as specialist and

  2. Mitochondrial and nuclear genetic variation across calving lagoons in Eastern North Pacific gray whales (Eschrichtius robustus).

    PubMed

    Alter, S Elizabeth; Ramirez, Sergio Flores; Nigenda, Sergio; Ramirez, Jorge Urbán; Bracho, Lorenzo Rojas; Palumbi, Stephen R

    2009-01-01

    Accurate knowledge of population structure in cetaceans is critical for preserving and managing breeding habitat, particularly when habitat is not uniformly protected. Most eastern gray whales return to their major breeding range each winter along the Pacific coast of Baja California, Mexico, concentrating in 3 major calving lagoons, but it is unknown whether genetic differences exist between lagoons. Previous photo-identification studies and genetic studies suggest that gray whales may return to their natal lagoons to breed, potentially resulting in the buildup of genetic differences. However, an earlier genetic study used only one genetic marker and did not include samples from Bahia Magdalena, a major calving lagoon not currently designated as a wildlife refuge. To expand on this previous study, we collected genetic data from the mitochondrial control region (442 bp) and 9 microsatellite markers from 112 individuals across all 3 major calving lagoons. Our data suggest that migration rates between calving lagoons are high but that a small but significant departure from panmixia exists between Bahia Magdalena and Laguna San Ignacio (Fisher's Exact test, P < 0.0001; F(ST) = 0.006, P = 0.025). Coalescent simulations show that the lack of extensive population structure may result from the disruption of structure due to whaling. Another possibility is that rates of migration have always been high (>10% per generation). In addition, microsatellite data showed evidence of a severe population bottleneck. Eastern gray whales are still recovering from the impacts of whaling on their breeding grounds, and these populations should be protected and monitored for future genetic changes.

  3. Tidal dynamics of the Terminos Lagoon, Mexico: observations and 3D numerical modelling

    NASA Astrophysics Data System (ADS)

    Contreras Ruiz Esparza, Adolfo; Douillet, Pascal; Zavala-Hidalgo, Jorge

    2014-09-01

    The tidal circulation patterns in the Terminos Lagoon were studied based on the analysis of 1 year of measurements and numerical simulations using a baroclinic 3D hydrodynamic model, the MARS3D. A gauging network was installed consisting of six self-recording pressure-temperature sensors, a tide gauge station and two current profilers, with pressure and temperature sensors moored in the main lagoon inlets. Model simulations were validated against current and sea level observations and were used to analyse the circulation patterns caused by the tidal forcing. The numerical model was forced with eight harmonic components, four diurnal ( K 1, O 1, P 1, Q 1) and four semi-diurnal ( M 2, S 2, N 2, K 2), extracted from the TPX0.7 database. The tidal patterns in the study area vary from mixed, mainly diurnal in the two main inlets of the lagoon, to diurnal in its interior. The tidal residual circulation inside the lagoon is dominated by a cyclonic gyre. The results indicate a net flux from the southwest Ciudad del Carmen inlet (CdC) towards the northeast Puerto Real inlet (PtR) along the southern side of the lagoon and the opposite in the northern side. The results indicate two areas of strong currents in the vicinity of the inlets and weak currents inside the lagoon. The area of strong currents in the vicinity of the CdC inlet is larger than that observed in the PtR inlet. Nevertheless, the current analysis indicates that the highest current speeds, which can reach a magnitude of 1.9 m s-1, occurred in PtR. A further analysis of the tide distortion in the inlets revealed that both passages are ebb dominated.

  4. How will shallow coastal lagoons respond to climate change? A modelling investigation

    NASA Astrophysics Data System (ADS)

    Brito, Ana C.; Newton, Alice; Tett, Paul; Fernandes, Teresa F.

    2012-10-01

    Coastal shallow lagoons are important ecosystems in terms of their high ecological relevance. They act as buffers of the land-sea interface, providing valuable ecosystem services such as nutrient recycling, decomposition of organic matter and removal of pollutants. Lagoons are regions of restricted exchange, subject to anthropogenic pressures that result in problems such as eutrophication. Because they are shallow, submerged primary producers play a prominent role in lagoon system metabolism. Furthermore, coastal lagoons are particularly vulnerable to global climate change and may act as 'sentinel systems'. Sea level rise already threatens to overwhelm some lagoons, such as Venice and Moroccan lagoons. Recent observations and studies have shown that a global climate change, especially the warming of the climate system and the sea level rise is unequivocal (IPCC, 2007). Therefore, the dCSTT-MPB model, which deals with nitrogen and chlorophyll concentrations in the water column and within the sediments, was used to explore a range of scenarios that aimed at representing these changes. The tendency of the light limitation due to the sea level rise is the potential degradation of the microphytobenthos community. This reduction would lead to stronger nitrogen fluxes from pore water to the water column, increasing significantly the nitrogen concentrations. No increase in the phytoplankton community was found because it is mainly influenced by the resuspension of microphytobenthos. High nitrogen concentration may be the first indication of an eutrophication event. Nonetheless, nitrogen may be exported to the sea and cause problems in the adjacent coastal waters. The increase in temperature did not lead to significant differences.

  5. [Temporal and spatial distribution of shorebirds (Charadriiformes) at San Ignacio Lagoon, Baja California Sur, Mexico].

    PubMed

    Mendoza, Luis Francisco; Carmona, Roberto

    2013-03-01

    Baja California Peninsula has several wetlands that represent important ecosystems for shorebirds. San Ignacio Lagoon is one of these sites, and supports 10% of the total abundance of shorebirds reported in this Peninsula. Since there is few information about this group in this area, we studied spatial and temporal changes in abundance and distribution of shorebirds in San Ignacio Lagoon. For this, we conducted twelve monthly censuses (October 2007-September 2008) on the entire internal perimeter of the lagoon, which we divided into four areas: two at the North and two at the South. We observed a seasonal pattern, with the lowest abundance in May (1 585 birds) and the highest in October (47 410). The most abundant species were Marbled Godwits (Limosa fedoa; 55% of the total records), Western Sandpipers (Calidris mauri; 23%), and Willet (Tringa semipalmata; 10%). All three species were more abundant in autumn; for both, the Marbled Godwit and Willet, we observed their highest numbers in winter and spring, while the Western Sandpiper showed noticeable oscillations, reaching a maximum in early winter (December). In summer, Marbled Godwit and Willet were the only birds present but in lower numbers. Here present the first records of the Pacific Red Knot (Calidris canutus roselaari) in the area. Bird abundance and species richness were influenced seasonally by migration and spatially by sites in the lagoon. The greatest shorebird abundance was in the South area of the lagoon, probably because of better accessibility to food. Our results allowed the inclusion of San Ignacio Lagoon in the Western Hemisphere Shorebirds Reserve Network (WHSRN) as a site of international importance.

  6. Design of a covered lagoon methane recovery system for a flush dairy

    SciTech Connect

    Williams, D.W.; Moser, M.; Smith, J.

    1996-12-31

    A lagoon-type methane recovery system was designed for the Cal Poly Dairy, which milks 130 cows with a total population of 296 animals. Most of the herd is housed in freestall barns where the manure is deposited on concrete and flushed with fresh or recycled water to an existing lagoon with a volume of 19,300 cubic meters. The design includes a new, primary covered lagoon of 17,000 cubic meters volume. The floating cover will be made of very low density polyethylene (VLDPE), with an area of 4,500 square meters. The predicted output of the lagoon is an average of over 310 cubic meters of biogas per day containing 60 percent methane. The methane production from the covered lagoon is adequate to produce 18 to 24 kW on a continuous basis from the present cow population. In order to account for future herd size increases, a 40 kW engine generator was specified to operate in parallel with the utility system at a varying level of output controlled by the biogas supply. The non-economic benefits of this covered lagoon include the demonstration of its operation to the students and visitors at Cal Poly which in turn will serve the California Dairy Community. Odor control is the most important non-economic benefit. Conversion of volatile solids to biogas and recovery and use of the biogas limits odor to surrounding areas. The economic benefits of the methane recovery system include the approximately 160,000 kWh of electricity produced annually, worth almost $13,000. Financial analyses for the project showed a payback of 13.7 years with a 4% internal rate of return.

  7. Eutrophication, water management, and the functioning of dutch estuaries and coastal lagoons

    SciTech Connect

    Nienhuis, P.H. )

    1992-12-01

    A number of European rivers (especially the Rhine) have a prevailing influence on the nutrient cycling of most Dutch estuaries. Owing to the increased loading of the estuaries with nitrogen and phosphorous compounds, effects of eutrophication on the biological communities are most evident in the tidal Western Wadden Sea and in a nontidal brackish lagoon, Veerse Meer. Whether the relation between changed nutrient loadings and changed biomass and production of primary and secondary producers in the turbid tidal Dutch ecosystems should be considered as a causal relation is questionable. The very widespread practice of lagoon modification confuses the effects of nutrient loading. 29 refs., 7 figs., 2 tabs.

  8. Project summary: Spreading lagooned sewage sludge on farm land: A case history

    SciTech Connect

    Robson, C.M.; Sommers, L.E.

    1995-06-01

    The City of Indianapolis, Indiana, was required to construct advanced wastewater treatment facilities at the existing Belmont Wastewater Treatment Plant. The most cost effective site for these new treatment facilities was the 10 sludge lagoons containing 420,000 cubic meters (111 million gallons) of digested sewage sludge stored for up to 50 years. The project consisted of the following major tasks: (1) obtaining approval from regulatory agencies; (2) obtaining cooperation of landowners and farmers; (3) removing, transporting, and applying the lagooned sludge to soil; and (4) monitoring the impact on crops.

  9. Biodiversity of Saline and Brakish Marshes of the Indian River Lagoon: Historic and Current Patterns

    NASA Technical Reports Server (NTRS)

    Schmalzer, Paul A.

    1995-01-01

    The Indian River Lagoon (IRL) crosses a zone of climatic transition. Historically, marshes dominated saline and brackish environments in the north of the lagoon, while mangroves became important to the south. Distribution of marsh communities was influenced by hydrology, salinity, soil characteristics, and fire, as well as periodic freezes. Marshes of the IRL have been greatly modified since the 1940s. Despite significant modifications, marsh plant species have not been lost from the region, but community and landscape patterns have been greatly modified and ecosystem processes altered.

  10. Fingerprints of lagoonal life: Migration of the marine flatfish Solea solea assessed by stable isotopes and otolith microchemistry

    NASA Astrophysics Data System (ADS)

    Dierking, Jan; Morat, Fabien; Letourneur, Yves; Harmelin-Vivien, Mireille

    2012-06-01

    The commercially important marine flatfish common sole (Solea solea) facultatively uses NW Mediterranean lagoons as nurseries. To assess the imprint left by the lagoonal passage, muscle carbon (C) and nitrogen (N) isotope values of S. solea juveniles caught in Mauguio lagoon in spring (shortly after arrival from the sea) and in autumn (before the return to the sea) were compared with values of juveniles from adjacent coastal marine nurseries. In addition, in the lagoon, sole otolith stable isotope (C and oxygen (O)) and elemental (11 elements) composition in spring and autumn, and the stable isotope composition (C and N) of organic matter sources in autumn, were determined. Overall, our data indicate that a distinct lagoonal signature existed. Specifically, lagoon soles showed a strong enrichment in muscle tissue 15N (>6‰) compared to their coastal relatives, likely linked to sewage inputs (see below), and a depletion in 13C (1-2‰), indicative of higher importance of 13C depleted terrestrial POM in the lagoon compared to coastal nurseries. In addition, over the time spent in the lagoon, sole otolith δ13C and δ18O values and otolith elemental composition changed significantly. Analysis of the lagoon sole foodweb based on C and N isotopes placed sediment particulate organic matter (POM) at the base. Seagrasses, formerly common but in decline in Mauguio lagoon, played a minor role in the detritus cycle. The very strong 15N enrichment of the entire foodweb (+7 to +11‰) compared to little impacted lagoons and coastal areas testified of important human sewage inputs. Regarding the S. solea migration, the analysis of higher turnover and fast growth muscle tissue and metabolically inert and slower growth otoliths indicated that soles arrived at least several weeks prior to capture in spring, and that no migrations took place in summer. In the autumn, the high muscle δ15N value acquired in Mauguio lagoon would be a good marker of recent return to the sea, whereas

  11. Reaction cross sections of the deformed halo nucleus 31Ne

    NASA Astrophysics Data System (ADS)

    Urata, Y.; Hagino, K.; Sagawa, H.

    2012-10-01

    Using the Glauber theory, we calculate reaction cross sections for the deformed halo nucleus 31Ne. To this end, we assume that the 31Ne nucleus takes the 30Ne+n structure. To take into account the rotational excitation of the core nucleus 30Ne, we employ the particle-rotor model (PRM). We compare the results to those in the adiabatic limit of PRM, that is, the Nilsson model, and show that the Nilsson model works reasonably well for the reaction cross sections of 31Ne. We also investigate the dependence of the reaction cross sections on the ground-state properties of 31Ne, such as the deformation parameter and the p-wave component in the ground-state wave function.

  12. Spatial and inter-annual variability of the macrobenthic communities within a coastal lagoon (Óbidos lagoon) and its relationship with environmental parameters

    NASA Astrophysics Data System (ADS)

    Carvalho, Susana; Moura, Ana; Gaspar, Miguel B.; Pereira, Paula; Cancela da Fonseca, Luís; Falcão, Manuela; Drago, Teresa; Leitão, Francisco; Regala, João

    2005-05-01

    The present work aims to analyse spatial and inter-annual variability in the benthic environment within the Óbidos lagoon, assessing the relationships between environmental characteristics and macrobenthic distribution patterns. Sediment samples were collected in February 2001 and 2002 for the study of macrofauna and biogeochemical parameters (sediment grain size, organic matter, organic carbon, chlorophyll a, and phaeopigments). Comparing 2001 to 2002, a general increase in the number of species, diversity and equitability indices was observed throughout the study area. Likewise, there was an increase of phytopigments and organic matter contents in the upper sediment layer. Based on the macrobenthic community patterns and environmental variables three main areas could be distinguished in both years: an outer area near the inlet mostly influenced by the sea, with very depressed number of species and abundance, and dominated by Saccocirrus papillocercus, Lekanesphaera levii, Microphthalmus similis and Nephtys cirrosa; an intermediate area located in the central part of the lagoon characterized by sandy sediment and low organic carbon, and colonized by a high diverse community with Hydrobia ulvae, Cerastoderma edule and Abra ovata as the most characteristic species; and the innermost area of the lagoon with muddy enriched sediments dominated by Heteromastus filiformis, oligochaetes, Scrobicularia plana, Cyathura carinata, Corophium acherusicum, phoronids, insect larvae and Corbula gibba. Deposit-feeders were dominant in the muddy sediments from the inner area, where suspension-feeders were also abundant. Carnivores were associated with clean sandy sediments from the inlet area and herbivores were more abundant within the central area.

  13. Electron-impact excitation of Ne4+

    NASA Astrophysics Data System (ADS)

    Griffin, D. C.; Badnell, N. R.

    2000-10-01

    We present the results of extensive close-coupling calculations of electron-impact excitation of the C-like ion, Ne4+. We first compare effective collision strengths determined from a 20-level Breit-Pauli R-matrix calculation with those obtained from a 20-level intermediate-coupling frame transformation (ICFT) R-matrix calculation. The ICFT method was also employed to perform two much larger calculations; we compare the effective collision strengths determined from these calculations with each other and with those obtained from the 20-level calculations in order to assess the effects of increasing both the size of the configuration-interaction expansion of the target and the size of the close-coupling expansion. Our final calculation, with 130 terms and 261 levels in the configuration-interaction expansion of the target and 66 terms and 138 levels in the close-coupling expansion, provides improved data for excitation between the levels of the 2s22p2, 2s2p3 and 2p4 configurations and the first close-coupling results for excitation to the levels of the 2s22p3ℓ configurations in Ne4+.

  14. Dispersion of Outflow from Small Rivers and Coastal Lagoons

    NASA Astrophysics Data System (ADS)

    Largier, J. L.; Basdurak, N. B.

    2013-05-01

    Along many tropical and subtropical coasts, waters enter the ocean via small streams or lagoons. These outflow plumes are known to be important to coastal productivity, but as pollutant loading increases they are also seen as an increasing source of coastal pollution. Physical processes in these small plumes interact in ways that are different to larger plumes, e.g., flow rate varies on short time scales, and the coriolis term is typically unimportant. After a brief review of dominant terms, attention will be given to observed plume patterns with a focus on the presence of low-salinity and outflow-related constituents nearshore. Data from studies off California and elsewhere will be used to suggest that there are common transport and mixing patterns at this scale. While the ultimate aim is to understand and model physical processes controlling dispersion of land-derived pollutants, at the very least one can recognize a spatial pattern of probability that can be characterized by primary physical parameters. Due to limited data on physical processes at the requisite resolution, numerical modeling is used to better understand processes and phenomena including inertial jets, buoyant plumes, alongshore flow, mixing and surface stresses. Ultimately, one can expect that a reasonable estimate of a probabilistic "zone of impact" can be obtained from knowledge of fundamental physical parameters that control transport and mixing. This link between physical forcing and response needs both a dynamical explanation and statistical support - yielding a general model that can be used for countless small inflows along many coasts. These features may be small but they are very common, and it is argued that their importance for coastal pollution and ecology is disproportionately big. The benefit of recognizing a transport-based zone of impact is that this pattern is the basis of distribution patterns for a variety of constituents, including dissolved and particulate contaminants

  15. Fate and persistence of glutaraldehyde and retention lagoon diversity of life at a natural gas storage facility

    SciTech Connect

    Derr, R.M.; Morris, E.A. III; Pope, D.H.

    1995-12-31

    In view of increasingly stringent environmental regulations concerning Produced water disposal, the natural gas industry needs to approximate the maximum amount of biocide which can be applied downhole and not adversely impact the local biology in retention lagoons receiving produced waters. Biocide treatment data from a microbially sour aquifer-storage natural gas facility, archived by the operations personnel, were incorporated into a study sponsored by the Gas Research Institute (GRI), Chicago, Illinois along with additional data from focused field sampling. The sandy assessed the persistence and fate of glutaraldehyde and its possible effects on diversity of life in the produced water system and outfall areas which receive the lagoon discharge under a National Pollution Discharge Elimination System (NPDES) permit. In this study, a mathematical model was constructed that incorporated experimentally-determined glutaraldehyde persistence, wellhead Outaraldehyde residuals, rates of water production, and lagoon specifications. The model was used to calculate the levels of glutaraldehyde in the lagoons as a function of time, based on the amount of glutaraldehyde applied downhole. The modeled results were used to assess the potential impacts of various levels of downhole treatment using glutaraldehyde and confirmed that the current treatment regime provided little potential for adverse environmental effects in the retention lagoons or the lagoon outfall areas. Chemical and biological sampling and diversity of life analyses were performed in the retention lagoon system and outfall areas to further test for environmental impacts relating to biocide use; no evidence of adverse effects was found.

  16. Ontogenetic patterns of concentration indicate lagoon nurseries are essential to common grunts stocks in a Puerto Rican bay

    NASA Astrophysics Data System (ADS)

    Burke, John Selden; Kenworthy, W. Judson; Wood, Lisa L.

    2009-03-01

    Estimates of abundance and size of three commercially exploited grunt species indicate ontogenetic changes in habitat utilization concentrate their juveniles within the lagoon of the Bay of La Parguera, Puerto Rico. Eleven biotopes, defined by four benthic structures (reef, mangrove, vegetation beds and unconsolidated sediments) and three geographic zones (inner lagoon, outer lagoon and bank shelf) were sampled randomly by visual surveys. French, bluestriped and white grunt ( Haemulon flavolineatum, Haemulon sciurus and Haemulon plumeri) were common in the bay and appeared to exhibit similar life history patterns of cross-shelf migration and habitat selection. Recently settled grunts were dispersed over vegetated and unconsolidated soft-bottom sediments of the bay. The juvenile stage occurred in highest densities in shallow lagoon biotopes among the submerged prop-roots of mangrove stands and on inshore reefs. Length data indicates that grunts migrate offshore to adult habitat via increasingly deep reefs. Indices of biotope nursery function based on standing stock estimates of juveniles identified three biotopes, all within the inner lagoon as essential habitat for juveniles of 5-10 cm length interval. This concentration of juveniles within biotopes of the lagoon could represent a bottleneck to recruitment for grunt stocks. Evidence that quantity and quality of lagoon nurseries may limit recruitment indicates that these areas represent a key component of a marine protected area designed to restore fisheries within the bay.

  17. Environmental variability and heavy metal concentrations from five lagoons in the Ionian Sea (Amvrakikos Gulf, W Greece)

    PubMed Central

    Pavloudi, Christina; Kalantzi, Ioanna; Apostolaki, Eugenia T.; Chatzigeorgiou, Giorgos; Chatzinikolaou, Eva; Pafilis, Evangelos; Papageorgiou, Nafsika; Fanini, Lucia; Konstas, Spyridon; Fragopoulou, Nina; Arvanitidis, Christos

    2016-01-01

    Abstract Background Coastal lagoons are ecosystems of major importance as they host a number of species tolerant to disturbances and they are highly productive. Therefore, these ecosystems should be protected to ensure stability and resilience. The lagoons of Amvrakikos Gulf form one of the most important lagoonal complexes in Greece. The optimal ecological status of these lagoons is crucial for the well-being of the biodiversity and the economic prosperity of the local communities. Thus, monitoring of the area is necessary to detect possible sources of disturbance and restore stability. New information The environmental variables and heavy metals concentrations, from five lagoons of Amvrakikos Gulf were measured from seasonal samplings and compared to the findings of previous studies in the area, in order to check for possible sources of disturbance. The analysis, showed that i) the values of the abiotic parameters vary with time (season), space (lagoon) and with space over time; ii) the variability of the environmental factors and enrichment in certain elements is naturally induced and no source of contamination is detected in the lagoons. PMID:27932906

  18. Effects of regional climate changes on the planktonic ecosystem and water environment in the frozen Notoro Lagoon, northern Japan.

    PubMed

    Katsuki, Kota; Seto, Koji; Noguchi, Takuro; Sonoda, Takeshi; Kim, JuYong

    2012-10-01

    Diatom fossils from core sediments and living diatoms from water samples of Notoro Lagoon in northern Japan were examined to evaluate natural climate effects on lagoon environmental changes. In 1974, the artificial inlet was excavated. Immediately after, the anoxic bottom water in Notoro Lagoon began to disappear due to an increasing water exchange rate. However, chemical oxygen demand (COD) in the bottom water of Notoro Lagoon gradually increased, with fluctuations, during the last 30 years. In addition, the dominant diatom assemblages in Notoro Lagoon shifted to ice-related and spring bloom taxa after the excavation. The dominant taxa of each year in the sediment core were also strongly related to the timing of lagoon ice melting. This is because the COD in Notoro Lagoon was affected by the deposited volume of blooming diatoms, which was controlled by the duration of ice cover and the timing of ice discharge to the Okhotsk Sea likely due to an air pressure pattern change over the northern North Pacific like the Pacific Decadal Oscillation (PDO).

  19. Stable isotopes in aquatic food web of an artificial lagoon in the Hangzhou Bay, China

    NASA Astrophysics Data System (ADS)

    Quan, Weimin; Shi, Liyan; Chen, Yaqu

    2010-05-01

    Stable isotope values, δ13C and δ15N, were determined for four primary producers and 19 dominant consumers in a small artificial lagoon located in Hangzhou Bay. Based on these results the major pathways for energy flow and trophic structure of the artificial lagoon ecosystem were characterized. The mean δ13C values for the 19 consumers ranged from -22.99‰ to -14.24‰. Apart from so-iny mullet Liza haematocheila, the other 18 consumers had intermediate δ13C values between those of epibenthic microalgae and particulate organic matter (POM). The results of a multiple source linear mixing model (IsoSource model) indicated that 50% or more of the organic carbon in the tissues of most consumers was derived from epibenthic microalgae. This indicated that these primary producers were the main food source fueling the lagoon food web. The mean δ15N values for the 19 consumers varied between 4.93‰ and 12.97‰ and indicated four trophic levels in the lagoon. Four macroinvertebrates and zooplankton represented the primary consumers, whilst the other 14 consumers occupied the secondary and tertiary consumer levels. The 19 consumers were divided into three trophic guilds (detritivores/suspension feeders, omnivores and carnivores).

  20. Metal pollution loading, Manzalah lagoon, Nile delta, Egypt: Implications for aquaculture

    NASA Astrophysics Data System (ADS)

    Siegel, F. R.; Slaboda, M. L.; Stanley, D. J.

    1994-03-01

    High cultural enrichment factors are found for Hg (13×), Pb (22.1×), and other potentially toxic metals (e.g., Sn, Zn, Cu, Ag) in the upper 20 cm of sediment cores from the southeastern Ginka subbasin of Manzalah lagoon, Nile delta, Egypt. Cores from other areas of the lagoon show little metal loading. Metal loading followed the closure of the Aswan High Dam, the availability of abundant cheap electricity, and the development of major power-based industries. Industrial wastes containing potentially toxic metals are dumped into the Nile delta drain system. The load carried by Bahr El-Baqar drain discharges into the Ginka subbasin, which acts as a sink and results in metal loading of the sediment deposited there. Further development of aquaculture in this subbasin, of food-stuff agriculture on recently reclaimed lagoon bottom, or where irrigation waters come from Bahr El-Baqar drain or its discharge should be halted or strictly limited until potentially toxic metals in the drain waters and sediment are removed and polluted input drastically reduced. This environmental assessment of heavy metals in aquaculture or agriculture development should extend to other waterbodies in the northern Nile delta, particularly Idku lagoon and lake Mariut, where industrial metal-bearing wastes discharge into the waterbodies.

  1. Validity of using backward Lagrangian Stochastic technique in measuring trace gas emission from treatment lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluates the accuracy of measuring trace gas emission from treatment lagoons using backward Lagrangian stochastic (bLs) technique. The bLs technique was originally developed for relatively homogeneous terrains without any obstacles causing significant windflow disturbance. The errors ass...

  2. Spatial patterns in coastal lagoons related to the hydrodynamics of seawater intrusion.

    PubMed

    Fiandrino, Annie; Ouisse, Vincent; Dumas, Franck; Lagarde, Franck; Pete, Romain; Malet, Nathalie; Le Noc, Sandrine; de Wit, Rutger

    2017-03-24

    Marine intrusion was simulated in a choked and in a restricted coastal lagoon by using a 3D-hydrodynamic model. To study the spatiotemporal progression of seawater intrusion and its mixing efficiency with lagoon waters we define Marine Mixed Volume (VMM) as a new hydrodynamic indicator. Spatial patterns in both lagoons were described by studying the time series and maps of VMM taking into account the meteorological conditions encountered during a water year. The patterns comprised well-mixed zones (WMZ) and physical barrier zones (PBZ) that act as hydrodynamic boundaries. The choked Bages-Sigean lagoon comprises four sub-basins: a PBZ at the inlet, and two WMZ's separated by another PBZ corresponding to a constriction zone. The volumes of the PBZ were 2.1 and 5.4 millions m(3) with characteristic mixing timescale of 68 and 84days, respectively. The WMZ were 12.3 and 43.3 millions m(3) with characteristics mixing timescale of 70 and 39days, respectively.

  3. Microbial community analysis of swine wastewater anaerobic lagoons by next-generation DNA sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic lagoons are a standard practice for the treatment of swine wastewater. This practice relies heavily on microbiological processes to reduce concentrated organic material and nutrients. Despite this reliance on microbiological processes, research has only recently begun to identify and enume...

  4. Anthropogenic Enrichment and Nutrients in Some Tropical Lagoons of Ghana, West Africa

    EPA Science Inventory

    As part of a larger study of demographic change in coastal Ghana, we measured the concentrations of major plant nutrients and phytoplankton chlorophyll in eight coastal lagoons with different land use and human population density. The purpose of our study was to relate human acti...

  5. The Assessment of Mangrove Sediment Quality in Mengkabong Lagoon: An Index Analysis Approach

    ERIC Educational Resources Information Center

    Praveena, Sarva M.; Radojevic, Miroslav; Abdullah, Mohd H.

    2007-01-01

    The objectives of this study are to use different types of indexes to assess the current pollution status in Mengkabong lagoon and select the best index to describe the Mengkabong sediment quality. The indexes used in this study were Enrichment Factor (EF), Geo-accumulation Index (Igeo), Pollution Load Index (PLI) and Marine Sediment Pollution…

  6. Vadose Zone Monitoring of Dairy Green Water Lagoons using Soil Solution Samplers.

    SciTech Connect

    Brainard, James R.; Coplen, Amy K

    2005-11-01

    Over the last decade, dairy farms in New Mexico have become an important component to the economy of many rural ranching and farming communities. Dairy operations are water intensive and use groundwater that otherwise would be used for irrigation purposes. Most dairies reuse their process/green water three times and utilize lined lagoons for temporary storage of green water. Leakage of water from lagoons can pose a risk to groundwater quality. Groundwater resource protection infrastructures at dairies are regulated by the New Mexico Environment Department which currently relies on monitoring wells installed in the saturated zone for detecting leakage of waste water lagoon liners. Here we present a proposal to monitor the unsaturated zone beneath the lagoons with soil water solution samplers to provide early detection of leaking liners. Early detection of leaking liners along with rapid repair can minimize contamination of aquifers and reduce dairy liability for aquifer remediation. Additionally, acceptance of vadose zone monitoring as a NMED requirement over saturated zone monitoring would very likely significantly reduce dairy startup and expansion costs. Acknowledgment Funding for this project was provided by the Sandia National Laboratories Small Business Assistance Program

  7. SEASONAL EMISSIONS OF AMMONIA AND METHANE FROM A HOG WASTE LAGOON WITH BIOACTIVE COVER

    EPA Science Inventory

    The paper discusses the use of plane-integrated (PI) open-path Fourier transform infrared spectrometry (OP-FTIR) to measure the flux of ammonia and methane from a hog waste lagoon before and after the installation of a bioactive cover. A computed tomography algorithm using a smoo...

  8. Biochar produced from anaerobically-digested fiber reduces phosphorus in dairy lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the use of biochar produced from anaerobic digester dairy fiber (ADF) to sequester phosphorus from dairy lagoons. The ADF was collected from a plugged flow digester, air dried to < 8% water content, and pelletized. Biochar was produced by slow pyrolysis in a barrel retort. The potential...

  9. Disentangling the relative influence of bacterioplankton phylogeny and metabolism on lysogeny in reservoirs and lagoons.

    PubMed

    Maurice, Corinne F; Mouillot, David; Bettarel, Yvan; De Wit, Rutger; Sarmento, Hugo; Bouvier, Thierry

    2011-05-01

    Previous studies indicate that lysogeny is preponderant when environmental conditions are challenging for the bacterial communities and when their metabolism is reduced. Furthermore, it appears that lysogeny is more frequent within certain bacterial phylogenetic groups. In this comparative study from 10 freshwater reservoirs and 10 coastal lagoons, we aim to disentangle the influence of these different factors. In eight reservoirs and four lagoons, lysogeny was detected by induction assays with mitomycin C, and induction significantly modified the bacterial community composition (BCC), whereas community composition remained constant in ecosystems in which lysogeny was not observed. Among the phylogenetic groups studied, the most abundant ones were Bacteroidetes and α-proteobacteria in lagoons, and β-proteobacteria and Bacteroidetes in reservoirs. These dominant groups comprised the highest proportions of inducible lysogens. In order to unravel the effects of bacterial metabolism from phylogeny on lysogeny, we measured bacterial community physiology and the specific activities of selected phylogenetic groups. The proportion of inducible lysogens within the α- and the β-proteobacteria decreased with increasing group-specific metabolism in lagoons and reservoirs, respectively. In contrast, this relationship was not observed for the other lysogen-containing groups. Hence, both host physiology and phylogeny are critical for the establishment of lysogeny. This study illustrates the importance of lysogeny among the most abundant phylogenetic groups, and further suggests its strong structuring impact on BCC.

  10. Use of Shallow Lagoon Habitats by Nekton of the Northeastern Gulf of Mexico

    EPA Science Inventory

    We compared nekton use of prominent habitat types within a lagoonal system of the northeastern Gulf of Mexico (GoM). These habitat types were defined by combinations of structure (cover type) and location (distance from shore) as: Spartina edge (<1m from shore), Spartina 3 m from...

  11. Monitoring of Malodorous Compounds from a Swine Waste Lagoon by an Equilibrium Technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The levels of malodorous compounds in the air above an anaerobic lagoon of a large swine farrowing operation were measured. Compounds were adsorbed onto silicone stir bars and retained compounds measured by gas chromatography-mass spectroscopy. Equilibration times were previously determined by exper...

  12. Water hyacinths for upgrading sewage lagoons to meet advanced wastewater treatment standards, part 2

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.; Mcdonald, R. C.

    1976-01-01

    Field tests using water hyacinths as biological filtration agents were conducted in the Mississippi gulf coast region. The plants were installed in one single cell and one multiple cell sewage lagoon systems. Water hyacinths demonstrated the ability to maintain BOD5 and total suspended solid (TSS) levels within the Environmental Protection Agency's prescribed limits of 30 mg/lBOD5 and 30 mg/l TSS. A multiple cell sewage lagoon system consisting of two aerated and one water hyacinth covered cell connected in series demonstrated the ability to maintain BOD5 and TSS levels below 30 mg/l year-round. A water hyacinth covered lagoon with a surface area of 0.28 hectare containing a total volume of 6.8 million liters demonstrated the capacity to treat 437,000 to 1,893,000 liters of sewage influent from 2.65 hectares of aerated lagoons daily and produce an effluent that met or exceeded standards year-round.

  13. Spatiotemporal distribution and composition of phytoplankton assemblages in a coastal tropical lagoon: Chilika, India.

    PubMed

    Srichandan, Suchismita; Kim, Ji Yoon; Bhadury, Punyasloke; Barik, Saroja K; Muduli, Pradipta R; Samal, Rabindro N; Pattnaik, Ajit K; Rastogi, Gurdeep

    2015-02-01

    The Asia's largest lagoon, Chilika, is a shallow water estuary and a designated "Ramsar" site located in the east coast of India. The spatiotemporal diversity of phytoplankton based on the monthly sampling between July 2011 and June 2012 was investigated in relation to physicochemical variables of the surface water column from 13 stations. The salinity was minimum (average 9) during the monsoon which was primarily due to riverine discharge. As the season progressed towards post-monsoon, average salinity of the whole lagoon reached to 10 which further increased to 20 during pre-monsoon season. A total of 259 species of phytoplankton, mostly dominated by the Bacillariophyta (138 species) followed by Dinophyta (38 species), Chlorophyta (32 species), Cyanophyta (29 species), Euglenophyta (18 species), and Chrysophyta (4 species), were recorded in this study. Different ecological sectors of the lagoon (except the northern sector) were dominated by diatoms, while the northern sector due to its freshwater regime supported large population of euglenoids. Based on the multivariate ordination analysis, salinity regime and light availability played important role in determining the distribution, diversity, and composition of phytoplankton communities. Overall, this study documented a very high diversity of phytoplankton and highlighted the importance of taking extensive sampling in getting a clearer understanding of phytoplankton community structure in less-studied environments such as Chilika lagoon.

  14. Spatial and Temporal Changes in the Microbial Community in an Anaerobic Swine Waste Treatment Lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine slurry is stored in pits beneath confinement buildings or in adjacent lagoons. This slurry is a valuable resource for crop fertilization and soil conditioning, but may also be a source of unpleasant odors. Microorganisms are crucial to all of the important processes that occur in anaerobic sto...

  15. Influence of seasonal changes on the microbial community in an anaerobic swine waste treatment lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine slurry is stored in pits beneath confinement buildings or in adjacent lagoons. This slurry is a valuable resource for crop fertilization and soil conditioning, but may also be a source of unpleasant odors. Microorganisms are crucial to all of the important processes that occur in anaerobic sto...

  16. Decline of phosphorus, copper, and zinc in anaerobic swine lagoon columns receiving pretreated influent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land application of both anaerobic lagoon liquid and sludge can increase nutrient accumulation beyond soil assimilative capacity and become a threat to water quality in regions with intensive confined swine production. In a 15-month meso-scale column study, we evaluated the effect of manure pretreat...

  17. Water quality and nitrogen mass loss from anaerobic lagoon columns receiving pretreated influent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control methods are needed to abate ammonia losses from swine anaerobic lagoons to reduce contribution of confined swine operations to air pollution. In a 15-month meso-scale column study, we evaluated the effect of manure pretreatment on water quality, reduction of N losses, and sludge accumulation...

  18. Process model for ammonia volatilization from anaerobic swine lagoons incorporating varying wind speeds and biogas bubbling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia volatilization from treatment lagoons varies widely with the total ammonia concentration, pH, temperature, suspended solids, atmospheric ammonia concentration above the water surface, and wind speed. Ammonia emissions were estimated with a process-based mechanistic model integrating ammonia ...

  19. Metal pollution loading, Manzalah lagoon, Nile delta, Egypt: Implications for aquaculture

    SciTech Connect

    Siegel, F.R.; Slaboda, M.L.; Stanley, D.J.

    1994-03-01

    High cultural enrichment factors are found for Hg (13 x), Pb (22.1 x), and other potentially toxic metals (e.g., Sn, Zn, Cu, Ag) in the upper 20 cm of sediment cores from the southeastern Ginka subbasin of Manzalah lagoon, Nile delta, Egypt. Cores from other areas of the lagoon show little metal loading. Metal loading followed the closure of the Aswan High Dam, the availability of abundant cheap electricity, and the development of major power-based industries. Industrial wastes containing potentially toxic metals are dumped into the Nile delta drain system. The load carried by Bahr El-Baqar drain discharges into the Ginka subbasin, which acts as a sink and results in metal loading of the sediment deposited there. Further development of aquaculture in this subbasin, of food-stuff agriculture on recently reclaimed lagoon bottom, or where irrigation waters come from Bahr El-Baqar drain or its discharge should be halted or strictly limited until potentially toxic metals in the drain waters and sediment are removed and polluted input drastically reduced. This environmental assessment of heavy metals in aquaculture or agriculture development should extend to other waterbodies in the northern Nile delta, particularly Idku lagoon and Lake Mariut, where industrial metal-bearing wastes discharge into the waterbodies. 21 refs., 7 figs., 3 tabs.

  20. Geochemical characterization of anthropogenic effects in coastal lagoons at the Northern Pacific coast of Mexico

    NASA Astrophysics Data System (ADS)

    Ruiz-Fernández, A. C.; Mellado-Vazquez, P. G.; Bojorquez-Sanchez, S.; Páez-Osuna, F.

    2007-05-01

    Sinaloa is a coastal state located in the Gulf of California that is characterized by an economy mostly based on agroindustry, fisheries, aquaculture and tourism. It has been recognized that the coastal lagoons neighboring the most developed economic areas of Sinaloa state are showing signs of infilling and eutrophication that have been related with the dumping of untreated effluents from agriculture croplands, aquaculture facilities and human settlements. The environmental impact to the lagoons of Navachiste, Santa María, Ohuira, Ensenada del Pabellón, Chiricahueto, Ceuta y Estero de Urías has been evaluated through the assessment of time dependent changes in the 210Pb-derived sedimentation rates and the sediment concentrations of geochemical constituents such as organic matter, carbonates and nutrients (N and P). 210Pb geochronology has shown that accretion rates and nutrient fluxes in some lagoons have considerably increased due to the development of the agriculture activities in the region. For instance, in Ohuira lagoon, at the area adjacent to the culture fields of El Fuerte Valley, sediment accumulation has increased ~5 times with respect to the pre-anthropogenic conditions in less than 20 years (0.06 to 0.32 cm yr-1), while C, N and P fluxes (mg cm-2 yr-1) increased almost 10, 10 and 13 fold, respectively (4.0-37 for OC, 0.6-6.0 for N and 0.1-7.0 for P).

  1. Optimal sensor locations for the backward Lagrangian stochastic technique in measuring lagoon gas emission

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the impact of gas concentration and wind sensor locations on the accuracy of the backward Lagrangian stochastic inverse-dispersion technique (bLS) for measuring gas emission rates from a typical lagoon environment. Path-integrated concentrations (PICs) and 3-dimensional (3D) wi...

  2. Evaluation of the anthropogenic influx of metallic pollutants into the Oualidia lagoon, Morocco

    NASA Astrophysics Data System (ADS)

    Maanan, Me.; Fattal, P.; Maanan, M.; Ruiz-Fernández, A.-C.; Sahabi, M.

    2012-04-01

    Numerous studies on the impact of anthropogenic activities on coastal water quality have been carried out in the last three decades, focusing mainly on urban expansion and agricultural development in coastal areas. In this study, we assess heavy metal pollution in the superficial and cored sediment of the Oualidia lagoon (Morocco). Superficial and cored sediment samples from the Oualidia lagoon were analyzed for Al, Fe, Cu, Zn, Pb, Mn, Ni, Cr, Hg and Cd using ICP-MS. Sediments near urban and agricultural areas are commonly contaminated with heavy metals and the concentrations found in surface sediments are significantly higher than those from 50-100 years ago. The concentrations of these elements decrease sharply with depth in the sediment column and the elements are preferentially enriched in the <2 µm-size fraction of the sediment. The enrichment factors (EF) and statistical analyses, demonstrated that heavy metals that might pose a risk (Pb, Cu and Hg) have become largely enriched in the lagoon sediments during the recent period of agricultural intensification. Ni and Cr are the main pollutants originating from urban sewage. Keywords: Coastal land use, heavy metals, sediment pollution, lagoon.

  3. Decline of phosphorus, copper, and zinc in anaerobic lagoon columns receiving pretreated influent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a 15-month meso-scale column study, we evaluated the effect of manure pretreatment on reduction of total suspended solids (TSS), total phosphorus (TP), soluble reactive phosphorus (SRP), copper (Cu) and zinc (Zn) in swine lagoons using (i) enhanced solid–liquid separation with polymer (SS) and (i...

  4. Geotextile filtration performance for lagoon sludges and liquid animal manures dewatering

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maintenance and control of liquid levels in anaerobic lagoons and storage ponds require liquid-solid separation as a pretreatment and periodic removal of accumulated sludges. Until local options become available, sludges can be contained, dewatered, and stored using geotextile filtration. We used a ...

  5. Cellulase and xylanase activity during the decomposition of three aquatic macrophytes in a tropical oxbow lagoon

    PubMed Central

    Sciessere, L.; Cunha-Santino, M. B.; Bianchini, I.

    2011-01-01

    Due to the connection between enzymatic activity and degradation of different fractions of organic matter, enzyme assays can be used to estimate degradation rates of particulate and dissolved organic carbon in freshwater systems. The aim of this study was to quantify and model the enzymatic degradation involving the decomposition of macrophytes, describing temporal activity of cellulases (EC 3.2.1.4 and EC 3.2.1.91) and xylanase (EC 3.2.1.8) during in situ decomposition of three aquatic macrophytes (Salvinia sp., Eichhornia azurea and Cyperus giganteus) on the surface and water-sediment interface (w-s interface) of an oxbow lagoon (Óleo lagoon) within a natural Brazilian Savanna Reserve. Overall, the enzymatic degradation of aquatic macrophytes in Óleo lagoon occurred during the whole year and was initiated together with leaching. Xylanase production was ca. 5 times higher than cellulase values due to easy access to this compound by cellulolytic microorganisms. Enzymatic production and detritus mass decay were similar on the surface and w-s interface. Salvinia sp. was the most recalcitrant detritus, with low mass decay and enzymatic activity. E. azurea and C. giganteus decomposition rates and enzymatic production were high and similar. Due to the physicochemical homogeneity observed in the Óleo lagoon, the differences between the decay rates of each species are mostly related with detritus chemical quality. PMID:24031706

  6. Transport of steroid hormones, phytoestrogens, and estrogenic activity across a swine lagoon/sprayfield system.

    PubMed

    Yost, Erin E; Meyer, Michael T; Dietze, Julie E; Williams, C Michael; Worley-Davis, Lynn; Lee, Boknam; Kullman, Seth W

    2014-10-07

    The inflow, transformation, and attenuation of natural steroid hormones and phytoestrogens and estrogenic activity were assessed across the lagoon/sprayfield system of a prototypical commercial swine sow operation. Free and conjugated steroid hormones (estrogens, androgens, and progesterone) were detected in urine and feces of sows across reproductive stages, with progesterone being the most abundant steroid hormone. Excreta also contained phytoestrogens indicative of a soy-based diet, particularly, daidzein, genistein, and equol. During storage in barn pits and the anaerobic lagoon, conjugated hormones dissipated, and androgens and progesterone were attenuated. Estrone and equol persisted along the waste disposal route. Following application of lagoon slurry to agricultural soils, all analytes exhibited attenuation within 2 days. However, analytes including estrone, androstenedione, progesterone, and equol remained detectable in soil at 2 months postapplication. Estrogenic activity in the yeast estrogen screen and T47D-KBluc in vitro bioassays generally tracked well with analyte concentrations. Estrone was found to be the greatest contributor to estrogenic activity across all sample types. This investigation encompasses the most comprehensive suite of natural hormone and phytoestrogen analytes examined to date across a livestock lagoon/sprayfield and provides global insight into the fate of these analytes in this widely used waste management system.

  7. Heavy metal contamination of the Sacca di Goro lagoon area (Po River Delta, Northern Italy)

    NASA Astrophysics Data System (ADS)

    Rapti-Caputo, Dimitra

    2010-05-01

    The lagoon area of the Sacca di Goro, within the Po River delta, is ca. 20 km2 wide, with a mean depth of 1.5 m and a mean salinity of 29%o. It holds a major naturalistic interest as well as an economic one due to the aquaculture activities (mussels and clams). In this lagoon system, the quality of the sea-bottom sediments is crucial not only for the cultivated species, but also for the potential bio-accumulation problems in heavy metals. The definition of the qualitative status of the lagoon sediments is crucial for adopting the best management strategies and the protection of the environmental conditions. We determined the concentration in SiO2, TiO2, Al2O3, Fe2O3, MgO, MnO, CaO, Na2O, K2O, P2O5, Ba, Ce, Co, Cr, La, Nb, Ni, Pb, Rb, Sr, Th, V, Y, Zn, Cu, Ga, Nd, S and Sr, of 31 samples homogeneously collected over the lagoon area. This large dataset allowed i) to define the environmental quality of the sediments, ii) to recognise the areas with the higher contamination risk; and iii) to emphasise the local occurrence of polluting phenomena associated to chromium, nickel, vanadium, cobalt, lead, zinc and copper.

  8. Heat flux measurements and modeling of malodorous compounds above an anaerobic swine lagoon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concentration of p-cresol and p-ethylphenol, two malodorants typical of swine waste, were measured at 0.5 m and 1.5 m above a waste treatment lagoon during two separate campaigns encompassing late winter through early spring and late spring through early summer. Concomitant collection of air te...

  9. Profile of Greenhouse Gas Emissions from Swine Lagoon: Implication on the Influence of Heat Fluxes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic lagoons are effective and low-cost tools to treat swine manure but they are also responsible for emissions of numerous atmospheric pollutants such as ammonia, greenhouse gases, and odors. The emissions of these pollutants are controlled by the interactions between the atmosphere, biochemic...

  10. Changes in the fish assemblages of a coastal lagoon subjected to gradual salinity increases.

    PubMed

    García-Seoane, Eva; Dolbeth, Marina; Silva, Cátia L; Abreu, Ana; Rebelo, José E

    2016-12-01

    This study analyses fish data to understand how the gradual increase of salinity registered in a coastal lagoon and consequently, anthropogenic disturbance, affected the fish communities. For that, fish assemblages of the Ria de Aveiro were sampled monthly in 3 years from different decades (1988, 1997 and 2012). Dominant species were Atherina boyeri, A. presbyter, Sardina pilchardus, Dicentrarchus labrax, Liza aurata and L. ramada. Significant differences in fish communities were detected among years in both terms of density and biomass. Results pointed out to a taxonomic and functional homogenization of fish assemblages in 2012, when salinity was higher and its range of variation across the whole lagoon more uniform. Marine species were clearly associated with 2012, while some freshwater species only appeared in 1988, reflecting the gradual salinity increase in the lagoon. Overall, both the structure and function of fish assemblages of Ria de Aveiro have changed over the time, which was attributed to human activities to maintain the lagoon operational.

  11. Comparison of metal concentrations in tissues of blue crab, Callinectes sapidus from Mediterranean Lagoons.

    PubMed

    Mutlu, Cengiz; Türkmen, Mustafa; Türkmen, Aysun; Tepe, Yalçın

    2011-09-01

    This study was performed to investigate the metal concentrations in muscle and gill of blue crab, Callinectes sapidus from Dörtyol Lake, Akyatan Lagoon, Paradeniz Lagoon and Çamlık Lagoon from the northeastern coastal area of Mediterranean Sea. So, the levels of cadmium, chromium, copper, iron, manganese, nickel, aluminum and zinc in tissues of specimens from the lagoons were determined by inductively coupled plasma optical emission spectrometer. The metal concentrations found in muscle tissue varied for Cd: 0.03-0.08, Cr: 0.05-0.13, Cu: 5.38-11.7, Fe: 21.1-38.2, Mn: 0.15-2.98, Ni: 0.24-0.45, Zn: 13.9-20.1 and Al: 1.2-13.7 mg/kg wet weight. Iron showed the highest levels in both tissues, and generally followed by zinc except gills. On the other hand, cadmium showed the lowest levels from all sites. Followed cadmium; chromium had the second lowest levels. The differences between mean metal concentrations from different sampling sites were statistically significant. Regional changes in metal concentration were observed in the tissues of the crabs, but these variations may not influence consumption advisories.

  12. Environmental Quality Assessment of Bizerte Lagoon (Tunisia) Using Living Foraminifera Assemblages and a Multiproxy Approach

    PubMed Central

    Alves Martins, Maria Virgínia; Zaaboub, Noureddine; Aleya, Lotfi; Frontalini, Fabrizio; Pereira, Egberto; Miranda, Paulo; Mane, Miguel; Rocha, Fernando; Laut, Lazaro; El Bour, Monia

    2015-01-01

    This study investigated the environmental quality of the Bizerte Lagoon (Tunisia) through an integrated approach that combined environmental, biogeochemical, and living benthic foraminiferal analyses. Specifically, we analyzed the physicochemical parameters of the water and sediment. The textural, mineralogical, and geochemical characteristics of the sediment, including total organic carbon, total nitrogen, simultaneously extracted metals (SEM), acid volatile sulfides (AVS), chlorophyll a, CaCO3, and changes in bacterial populations and carbon isotopes were measured. The SEM/AVS values indicated the presence of relatively high concentrations of toxic metals in only some areas. Foraminiferal assemblages were dominated by species such as A. parkinsoniana (20–91%), Bolivina striatula (<40%), Hopkinsina atlantica (<17%), and Bolivina ordinaria (<15%) that cannot be considered typical of impacted coastal lagoons both in Mediterranean and northeast Atlantic regions. The results of this work suggest that Bizerte Lagoon is a unique setting. This lagoon is populated by typical marine species that invaded this ecosystem, attracted not only by the prevailing favorable environmental conditions but also by the abundance and quality of food. The results indicate that the metal pollution found in some areas have a negative impact on the assemblages of foraminifera. At present, however, this negative impact is not highly alarming. PMID:26372655

  13. Reducing phosphorus in swine effluent with aluminum chloride treatment during lagoon cleanout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphorus (P) runoff from agricultural lands fertilized with swine manure can be a significant environmental issue. The objective of this study was to evaluate the effect of aluminum chloride (AlCl3) applications to a swine lagoon during total clean out on P concentrations in manure and runoff wat...

  14. Spatial characterization of water quality in a karstic coastal lagoon without anthropogenic disturbance: a multivariate approach

    NASA Astrophysics Data System (ADS)

    Medina-Gómez, Israel; Herrera-Silveira, Jorge A.

    2003-11-01

    Dzilam Lagoon, located in the central coast of Yucatan, Gulf of Mexico, is a shallow water body with average depth of 0.6 m and area of 9.4 km 2. Numerous groundwater inputs are distributed along the system representing a continuous source of nitrates and silicates. Due to scarce anthropogenic activity, it is well preserved. Such pristine conditions suggest that changes on nutrient dynamics are mostly related to natural behavior. Monthly samples were taken from September 1998 to August 1999. Physicochemical parameters, inorganic nutrients and chlorophyll- a were measured in nine stations. A multivariate analysis showed salinity gradient and nutrient concentration as the most significant variables in describing lagoon hydrologic heterogeneity. On the basis of those critical parameters, classification analysis of Dzilam Lagoon identified three hydrological affinity zones (HAZ); East and West Zone characterized by higher water residence time and lower salinities during the rainy season; Central Zone with lower residence time and lower inorganic nutrients concentration. Dzilam Lagoon was a NO 3- sink and a net source for NO 2- and NH 4+. Soluble reactive phosphorus was slightly defined and soluble reactive silica was close to conservative condition.

  15. Spatio-temporal impacts of dairy lagoon water reuse on soil: Heavy metals and salinity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diminishing freshwater resources have brought attention to the reuse of degraded water as a water resource rather than a disposal problem. Dairy lagoon water is degraded water that is often in large supply on concentrated animal feeding operations (CAFOs), but the impact and sustainability of its r...

  16. Use of geotextile tubes with chemical amendments to dewater dairy lagoon solids.

    PubMed

    Worley, J W; Bass, T M; Vendrell, P F

    2008-07-01

    Three geo-textile filtration tubes were used to dewater lagoon solids from a first stage dairy lagoon using chemical amendments (aluminum sulfate and a polymer) to enhance the separation process. This experiment had previously been done without chemical amendment. The chemical amendments speeded the dewatering process so that filling could be accomplished sooner, and also increased the removal rate of nutrients, especially phosphorus into the solid phase. Chemically amended slurry was pumped from the lagoon into the tube with the filtered liquid seeping from the tube and returning to the lagoon. Each tube was filled five to six times at 2-5-day intervals, and then allowed to dewater for 2 weeks before sampling the solid fraction in the tube. Separation efficiency improved from 79% to 99% for phosphorous and from 92% to 100% for organic nitrogen with chemical amendment. Time required for dewatering was significantly reduced by chemical amendment. Cost for the tube was approximately $10/m(3) of recovered solids with no chemical amendment and cost including the chemicals was approximately $14/m(3) of recovered solids.

  17. Hydrographic Study of a Highly Stratified River Mouth Estuary. Alvarado Coastal Lagoon, México

    NASA Astrophysics Data System (ADS)

    Perales-Valdivia, H.; Sanay, R.

    2014-12-01

    Two 24 hours surveys on high and low river discharge conditions were used to describe the hydrography and the currents at the entrance of Alvarado Coastal Lagoon, México, located at the southwestern coast of the Gulf of México. This study represent the first of this kind in this lagoon. The Alvardo Coastal Lagoon sustains several economical fisheres in the region, including the shrimp fishery. The inlet of the Alvarado Coastal Lagoon is a microtidal rivermouth estuary. In each survey, towed ADCP and hydrographic data were sampled during a diurnal tidal cycle for three across-inlet transects located near the mouth. 12 track repetitions were completed allowing to distinguish the subtidal and tidal signals. In both runoff conditions a salt wedge was present, and showed surface-bottom salinity difference up to 35 psu. During high river discharge condition the salt wedge was present only during flood tide. The thicknesses of the interface, and upper and bottom layers oscillated according the tide. The water surface layer was always toward the ocean. During low river discharge condition the salt wedge was present for the whole tidal cycle. The vertical position of the interface oscillated as the tide did but keeping a constant thickness.

  18. Occurrence and Diversity of Tetracycline Resistance Genes in Lagoons and Groundwater Underlying Two Swine Production Facilities

    USGS Publications Warehouse

    Chee-Sanford, J. C.; Aminov, R.I.; Krapac, I.J.; Garrigues-Jeanjean, N.; Mackie, R.I.

    2001-01-01

    In this study, we used PCR typing methods to assess the presence of tetracycline resistance determinants conferring ribosomal protection in waste lagoons and in groundwater underlying two swine farms. All eight classes of genes encoding this mechanism of resistance [tet(O), tet(Q), tet(W), tet(M), tetB(P), tet(S), tet(T), and otrA] were found in total DNA extracted from water of two lagoons. These determinants were found to be seeping into the underlying groundwater and could be detected as far as 250 m downstream from the lagoons. The identities and origin of these genes in groundwater were confirmed by PCR-denaturing gradient gel electrophoresis and sequence analyses. Tetracycline-resistant bacterial isolates from groundwater harbored the tet(M) gene, which was not predominant in the environmental samples and was identical to tet(M) from the lagoons. The presence of this gene in some typical soil inhabitants suggests that the vector of antibiotic resistance gene dissemination is not limited to strains of gastrointestinal origin carrying the gene but can be mobilized into the indigenous soil microbiota. This study demonstrated that tet genes occur in the environment as a direct result of agriculture and suggested that groundwater may be a potential source of antibiotic resistance in the food chain.

  19. Groundwater Discharge into Intermittently Closed and Open Lakes and/or Lagoons (ICOLLs) via Radon-222

    NASA Astrophysics Data System (ADS)

    Sadat-Noori, M.; Santos, I. R.; Tait, D. R.; McMahon, A.; Kadel, S.; Maher, D. T.

    2015-12-01

    Intermittently Closed and Open Lakes and Lagoons (ICOLLs) are brackish coastal water bodies with an intermittent connection to the ocean that is closed periodically due to the accumulation of marine sediment forming an entrance berm. ICOLLs have dynamic coastal systems that may be vulnerable to minor changes in catchment hydrology. However, little is known regarding the impacts of groundwater on the hydrological cycles of ICOLLs. The relative contribution of rainfall versus groundwater discharge in two ICOLLs (Welsby, and Mermaid Lagoon) and a nearby wetland (South Welsby Lagoon) located on Bribie Island (Australia) were investigated using radon (222Rn) as natural geochemical groundwater tracer. Four seasonal surveys were undertaken to quantify the temporal and spatial groundwater dynamics of the ICOLLs. Radon contour maps revealed temporal and spatial changes over the study period. The estimated groundwater discharge rates from a radon-mass balance were 3.4±3.1, 7.3±9.8 and 2.6±3.8 cm d-1 in Weslby, South Weslby and Mermaid Lagoons, respectively. These values are at least 8-fold greater than rainfall (1420 mm per year, or 0.4 cm d-1). Assuming very minor surface water flows (not perceived during field surveys), this demonstrates that these systems are groundwater-dominated and their hydrology can be influenced by regional changes in groundwater level.

  20. Neuroendocrine disruption and health effects in Elliptio complanata mussels exposed to aeration lagoons for wastewater treatment.

    PubMed

    Gagné, F; Blaise, C; André, C; Gagnon, C; Salazar, M

    2007-06-01

    The purpose of this study was to examine neuroendocrine-disrupting effects of two domestic wastewater aeration lagoons on freshwater mussels. Mussels were caged and placed in two final aeration lagoons for treating domestic wastewaters for 60 days, at a site 1km downstream of the dispersion plume on the eastern shores of the Richelieu River; the western shore served as the reference site. The mussels were analysed for gonad activity, oxidative metabolism of xenobiotics, stress biomarkers and neuroendocrine status (monoamine and arachidonic acid metabolism). The domestic wastewaters produced many different effects at all levels examined. The gonado-somatic index and vitellogenin-like proteins were significantly induced in both aeration lagoons and gonad pyrimidine synthesis (aspartate transcarbamylase activity) was significantly reduced, indicating that vitellogenin-like proteins were produced while DNA synthesis in gametes remained constant. Biomarkers of oxidative metabolism revealed that global heme oxidase (HO), glutathione S-transferase and xanthine (caffeine) oxydoreductase (XOR) activities were significantly induced in at least one of the aeration lagoons, but not downstream of the dispersion plume. The activities of 7-ethoxyresorufin (cytochrome P4501A1), dibenzoylfluorescein (cytochrome P450 3A4 and 3A5) and benzoyloxyresorurufin (cytochrome P450 3A4 and 2B6) dealkylases were readily induced by substances sharing structural similarities with coplanar polyaromatic hydrocarbons and hydroxylated or aminated aromatic or cyclic hydrocarbon compounds such as pharmaceuticals or steroids in the domestic wastewaters. Biomarkers of toxic stress revealed that exposure to aeration lagoons led to increased production of metallothioneins, lipid peroxidation and DNA strand breaks, with decreased heme oxygenase activity. LPO was significantly correlated with XOR, HO and cytochrome P4501A1 activities. Neuroendocrine effects included significant increases in dopamine and

  1. Distribution, fate and effects of pesticide residues in tropical coastal lagoons of northwestern Mexico.

    PubMed

    Carvalho, F P; Gonzalez-Farias, F; Villeneuve, J P; Cattini, C; Hernandez-Garza, M; Mee, L D; Fowler, S W

    2002-11-01

    Analyses of pesticide residues in sediments, water and biota of the Altata-Ensenada del Pabellon coastal lagoon system in Sinaloa, Mexico, showed the presence of organochlorine and organophosphorus compounds. For all the compounds analysed, concentrations in sediments were higher near the points of water discharge from ponds and drainage from the agricultural area. Among the organochlorines, total DDTs displayed the largest sedimentary reservoir, followed by total endosulfans and chlorpyrifos. In sediments, as well as in biota, pp'-DDT concentrations were lower than those of DDT metabolites, which confirms the reduction in the previous massive use of this compound in agriculture. Endosulfan is currently used in the region and endosulfan residues in lagoon sediments attained levels considered to be toxic to meiofauna, therefore constituting an ecological risk to lagoon ecosystems. There was a large sedimentary reservoir of chlorpyrifos but its ecotoxicological risk is difficult to assess due to lack of adequate comparative data. Nevertheless, concentrations of chlorpyrifos which approach acute toxic levels for shrimp were recorded in lagoon water. This suggests that drainage from agricultural fields during high runoff may, on occasion, cause mass mortality of shrimp and fish Organophosphorus pesticides are widely regarded to degrade very rapidly in aquatic systems. Experimental research performed with 14C-labelled chlorpyrifos and parathion has shown that they may be stabilised for relatively long periods of time through sediment-water partitioning. This extension of their environmental half-lives increases their potential for impacting on coastal ecosystems. Since organophosphorus pesticides are highly toxic for aquatic organisms at concentrations generally lower than organochlorines, their presence in the lagoon water and sediment is a matter for much concern. The increased use of tropical coastal lagoons for shrimp and fish farming requires the implementation of

  2. Wet nitrogen and phosphorus deposition in the eutrophication of the Lagos Lagoon, Nigeria.

    PubMed

    Oladosu, Najeem O; Abayomi, Akeem A; Olayinka, Kehinde O; Alo, Babajide I

    2017-02-15

    Air pollution is influenced by wind-aided particulate suspension, open-air waste burning, and fossil fuel combustion. The pollutants from these sources eventually deposit on ambient surfaces. Atmospheric wet deposition into Lagos Lagoon may be significant additions to the nutrient levels of the eutrophic lagoon. Precipitation was monitored at three stations in the Lagos Lagoon basin from May to November, 2012, in order to estimate the contribution of wet deposition to the nutrient cycles of the lagoon. Water samples were digested with potassium persulfate, and the species of phosphorus (P) and nitrogen (N) were analyzed by colorimetric methods. The mean [NO3(-)+NO2(-)]-N level was 0.39 ± 0.51 kg ha(-1) month(-1). The average total N was 3.16 ± 6.39 kg ha(-1) month(-1). The mean soluble reactive P was lower than the [NO3(-)+NO2(-)]-N averaging 0.06 ± 0.09 (at control site S2) to 0.24 ± 0.10 kg ha(-1) month(-1) (at site S1). Average total P was 1.25 ± 0.82 kg ha(-1) month(-1). The annual total N (May-September) was 4.55 (at S2) to 32.4 kg ha(-1) year(-1) (at S3). The annual total P (May-November) over Lagos Lagoon basin was 5.06 kg ha(-1) year(-1) (at S2). This study demonstrated that wet deposition of anthropogenically derived nutrients to the Lagos Lagoon is ongoing and may represent a considerable proportion of the total nutrient loading to it. The increased P availability in the wet deposition is likely responsible for the water hyacinths, which usually blossom on Lagos Lagoon during the late rainy season, and the reported harmattan-season bottom water hypoxia.

  3. Determination of water quality variables, endotoxin concentration, and Enterobacteriaceae concentration and identification in southern High Plains dairy lagoons.

    PubMed

    Purdy, C W; Clark, R N; Straus, D C

    2010-04-01

    The objectives of this study were to determine the concentration of endotoxin, determine 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collected in triplicate from the north, south, east, and west quadrants of each body of water. The mean (+/- SEM) winter dairy lagoon endotoxin concentration was significantly higher (9,678+/-1,834 ng/mL) than the summer concentration (3,220+/-810 ng/mL). The mean endotoxin concentration of the 2 control lakes (summer: 58.1+/-8.8 ng/mL; winter: 38.6+/-4.2 ng/mL) was significantly less than that of the dairy lagoons. Two hundred-one Salmonella enterica spp. isolates were identified, 7 serovars were recovered from the dairy lagoons, and 259 Salmonella ssp. were identified from 5 other dairy locations (milk barn, ditch effluent, settling basin, feed alley pad flush, and center pivots). Twenty-eight Salmonella spp. were identified from center pivot water. Escherichia coli O157:H7 pathogens were isolated from other dairy locations but not from lagoons. Neither Salmonella spp. nor E. coli O157:H7 were identified from control lakes. Enterobacteriaceae opportunistic pathogens were isolated from both dairies and control lakes. Important mesophilic and thermophilic catabolic (to manure biosolids) fungal isolates were identified from dairy effluent locations, but no thermophilic fungal isolates were cultured from the control lakes. Adequate curing of green forage following center pivot irrigation is important to kill lagoon water enteric pathogens, even though the lagoon water is mixed with fresh water. Recirculating lagoon water to flush the feed alley pad, where cows stand while eating, to remove manure and using lagoon water to abate dairy dust in loafing pens and unimproved dairy roads is inconsistent with good environmental practice management.

  4. The performance of benthic indicators of ecological change in Adriatic coastal lagoons: throwing the baby with the water?

    PubMed

    Munari, C; Mistri, M

    2008-01-01

    The ecological quality of 127 stations from six Adriatic coastal lagoons was assessed using a suite of biotic indices: H', d, 1-lambda', Delta(*), Delta(+), W, AMBI, BOPA and FINE. The analysis indicated the difficulties in deriving and using the existing indices from benthic communities in highly variable environmental conditions in coastal lagoons. Different metrics rendered different results: the use of H' resulted in the classification of all stations as "Moderate/Poor/Bad", whereas BOPA classified the majority of the stations as "Good/High". Using Delta(+), most of the stations resulted as "Not anthropogenically impacted", while the W-statistics gave 82 stations as "Undisturbed" and 45 as "Moderately/Grossly disturbed". AMBI classified 55 stations as "High/Good" and 72 as "Moderate/Poor/Bad", whereas those were 32 and 95 with FINE, respectively. The latter, which was developed just for Italian coastal lagoons, was the most conservative among the indices studied. Yet, it showed the highest correlation with the species/abundance matrix. Using indices developed for coastal waters in lagoons can give the distorted indication that the water body is degraded, when it might be just a natural, low diversity, high abundance community, i.e. a lagoonal community. Moreover, the outcome of the use of a certain index has a financial dimension such that lagoons misclassified as being "poor status" will then require expensive remediation measures. For the lagoons studied, there is probably an adequate quality and quantity of benthic data available for making management decisions, but this study highlights the limits of the existing indices for lagoonal ecosystems. The challenge for the next future is to couple long term conservation of the natural environment with the highly productive activities carried out in lagoonal ecosystems.

  5. Hydrodynamics, temperature/salinity variability and residence time in the Chilika lagoon during dry and wet period: Measurement and modeling

    NASA Astrophysics Data System (ADS)

    Mahanty, M. M.; Mohanty, P. K.; Pattnaik, A. K.; Panda, U. S.; Pradhan, S.; Samal, R. N.

    2016-08-01

    This paper investigated the hydrodynamics, spatio-temporal variability of temperature/salinity and the residence time of tracer concentrations in a largest brackish water coastal lagoon in Asia, namely the Chilika lagoon, India. An integrated approach combined the measurement and 2D hydrodynamic-advection/dispersion model is used to simulate circulation and temperature/salinity, and estimated the water residence time in lagoon under different forcing mechanisms, such as tide, wind and freshwater discharge during the dry and wet periods. Water circulation inside the lagoon is simulated when wind is included with the tide only forcing during dry period, and freshwater influx is included with the tide and wind forcing during wet period. Under the realistic forcing conditions, the computed temporal variability of water temperature and salinity are well correlated with the measurements in both the periods. The spatial variations of water temperature within the lagoon is influenced by the meteorological conditions, tide and freshwater influx as well as the shallowness of the lagoon, whereas the salinity is spatially controlled by the freshwater influx from the riverine system and seawater intrusion through the tidal inlets. The numerical model results show that in the Chilika lagoon tidal and river influx affect significantly the residence time spatially, and is site specific. The residence time varies from values of 4-5 days in the outer channel (OC) and 132 days at the northern sector (NS) in the main body of lagoon. The current study represents a first attempt to use a combined model approach, which is therefore, a useful tool to support the ecological implication of the lagoon ecosystem.

  6. Structure and functioning of Mediterranean lagoon fish assemblages: A key for the identification of water body types

    NASA Astrophysics Data System (ADS)

    Franco, Anita; Franzoi, Piero; Torricelli, Patrizia

    2008-09-01

    Knowledge on the structure and functioning variability of transitional water fish assemblages may help in finding out the main descriptors for identifying different water body types for which specific biological reference conditions can be reliably derived. Fish assemblages from 19 Mediterranean lagoons were therefore investigated by evaluating the variability of their structure and functioning, and by relating it to the lagoons' environmental features. Fish assemblage structure was measured by its species richness. Functioning was measured by categorizing fish species into functional categories (or guilds) according to their use of lagoon habitat, feeding and reproduction, and by defining the functional structure of fish assemblages as the relative number of species per guild in each lagoon. Mediterranean lagoons' fish assemblages were found to be more similar to each other in their functional structure than in the taxonomical composition, thus confirming a shared functional role of these environments for biological communities. Lagoon local features, such as the lagoon area, its habitat heterogeneity and average salinity, significantly affected the total species richness and the different use that fish make of the lagoon environment, hence playing a primary role in the assessment of these water body types. Latitude also influenced the variability of fish assemblages in the Mediterranean lagoons investigated, with particular regard to their functioning as feeding and reproductive grounds for fish. These results are compared with previous studies and, although this limited the investigation to structural aspects only, were found to confirm in part the previous results and also added new insights about the key factors affecting the functioning of transitional water systems.

  7. Meiobenthic communities in permanently open estuaries and open/closed coastal lagoons of Uruguay (Atlantic coast of South America)

    NASA Astrophysics Data System (ADS)

    Kandratavicius, N.; Muniz, P.; Venturini, N.; Giménez, L.

    2015-09-01

    This study aimed to determine if estuarine meiofaunal communities of Uruguay (South America) vary between permanently open estuaries and open/closed coastal lagoons, or if they respond to the sediment composition. In Uruguay, estuaries and coastal lagoons vary in the degree of connectivity to the sea and in the sediment composition; sediments in estuaries are characterized by fine-medium sands but sediments vary from lagoon to lagoon (either fine-medium or coarse sand). Taxa richness (total = 16) showed less temporal variability in lagoons than in estuaries, due to patterns of presence/absence of the less abundant taxa. However, no major response to habitat was found in the most abundant groups: polychaetes (6% of total fauna) were on average 5% more abundant in lagoons than in estuaries. Some level of zonation, within estuaries and lagoons, was found in the most abundant groups, nematodes (63% of total fauna) and copepods (15%) in response to medium and fine sands. In addition, sediment type modulated seasonal patterns in the frequency of presence/absence in ostracods, polychaetes and oligochaetes. For instance, in polychaetes and ostracods the increase in the frequency of absences, occurring from summer to winter, was stronger in lagoons and estuaries dominated by fine sands. The lagoon habitat appears to ameliorate the effects of unfavourable (winter) conditions in less abundant meiofaunal taxa. In summary, sediment fractions explain spatial patterns in the average abundance of organisms (e.g. nematodes) as well as the seasonal changes in frequency of presence/absence (e.g. polychaetes).

  8. Macrofaunal patterns and animal-sediment relationships in Uruguayan estuaries and coastal lagoons (Atlantic coast of South America)

    NASA Astrophysics Data System (ADS)

    Giménez, L.; Venturini, N.; Kandratavicius, N.; Hutton, M.; Lanfranconi, A.; Rodríguez, M.; Brugnoli, E.; Muniz, P.

    2014-03-01

    Estuaries vary considerably in geomorphology, hydrology and in the properties of sediments. Structure of benthic communities may respond to the interaction of these estuarine characteristics, resulting in between site differences. This work evaluated several hypothetical scenarios to explain variation in macrofaunal communities in permanently open estuaries and open/closed coastal lagoons of the coast of Uruguay, South America. Of particular relevance were three hypothetical scenarios: (1) that sediment characteristics, temperature or conductivity may explain variation in fauna between estuarine habitat types (estuaries vs. lagoons), (2) that fauna may not vary between habitat types, but may vary among sites in response to environmental variables and (3) that fauna differed between habitat types but patterns were not clearly being mediated by the measured environmental variables. Scenario 1 was discarded because none of the observed environmental variables showed a significant habitat effect. Patterns of species richness differed between lagoons and estuaries in accordance with scenario 3; richness was higher in open/closed lagoons than in estuaries. The abundance of three important infaunal species supported scenario 2: these species varied considerably among sites in response to the proportion of different sand fractions. Fine sands, common in all estuaries and in a lagoon, were characterised by polychaetes (Laeonereis acuta and Alitta succinea) whereas coarse sands, found in two lagoons were characterised by a bivalve, Erodona mactroides. Another three species responded to sediment but did not show clear site to site variation in abundance. Lagoons differ from estuaries in their higher site to site variation in sediment composition and in the diversity of community variants: lagoons may therefore increase regional diversity as compared to estuaries. We conclude that sediment type played a strong role in explaining variations in macrofaunal abundance among

  9. Residence times in a hypersaline lagoon: Using salinity as a tracer

    NASA Astrophysics Data System (ADS)

    Mudge, Stephen M.; Icely, John D.; Newton, Alice

    2008-04-01

    Generally the waters of the Ria Formosa Lagoon, Portugal have a short residence time, in the order of 0.5 days (Tett, P., Gilpin, L., Svendsen, H., Erlandsson, C.P., Larsson, U., Kratzer, S., Fouilland, E., Janzen, C., Lee, J., Grenz, C., Newton, A., Ferreira, J.G., Fernandes, T., Scory, S., 2003. Eutrophication and some European waters of restricted exchange. Continental Shelf Research 23, 1635-1671). This estimation is based on the measurements of currents and the modelling of water exchange at the outlets to the ocean. However, observations of the temperature and salinity in the inner channels imply that residence time is greater in these regions of the lagoon. To resolve this apparent contradiction, spatial measurements of the temperature and salinity were made with a meter for conductivity, temperature and depth along the principal channels of the western portion of the lagoon, with a sampling frequency of two per second. Evaporation rates of 5.4 mm day -1 were measured in a salt extraction pond adjacent to the lagoon and used to determine the residence time through salinity differences with the incoming seawater. In June 2004, the water flooding in from the ocean had an average salinity of 36.07 which contrasted with a maximum of 37.82 at mid ebb on a spring tide, corresponding to a residence time of >7 days; the mean residence time was 2.4 days. As the tide flooded into the channels, the existing water was advected back into the lagoon. Although there was a small amount of mixing with water from another inlet, the water body from the inner lagoon essentially remained distinct with respect to temperature and salinity characteristics. The residence time of the water was further prolonged at the junction between the main channels, where distinct boundaries were observed between the different water masses. As the water ebbed out, the shallow Western Channel was essentially isolated from the rest of the outer lagoon, and the water from this channel was forced

  10. La fin du jeûne?

    PubMed Central

    Naugler, Christopher; Sidhu, Davinder

    2014-01-01

    Résumé Objectif Présenter une mise à jour sur l’utilité clinique de ne pas être à jeun par rapport à l’être pour l’analyse des lipides dans le but d’améliorer l’observance par les patients, leur sécurité et l’évaluation clinique dans les tests du cholestérol. Qualité des données Les recommandations sont classées comme étant fondées sur des données probantes fortes, acceptables ou faibles (conflictuelles ou insuffisantes), selon les classifications adoptées par le Groupe d’étude canadien sur les soins de santé préventifs. Message principal Le dépistage de la dyslipidémie comme facteur de risque de coronaropathie et la prescription de médicaments hypolipidémiants sont des activités importantes en soins primaires. De récentes données probantes remettent en question la nécessité d’être à jeun pour la mesure des lipides. Dans des études sur la population, le cholestérol total, le cholestérol à lipoprotéines de haute densité et le cholestérol à lipoprotéines autres qu’à haute densité variaient tous d’en moyenne 2 % à jeun. Pour un dépistage de routine, la mesure du cholestérol sans être à jeun est maintenant une option de rechange raisonnable à l’analyse à jeun. Pour les patients diabétiques, l’exigence d’être à jeun peut représenter un important problème de sécurité en raison des possibilités d’hypoglycémie. Pour la surveillance des triglycérides et du cholestérol à lipoprotéines de basse densité chez les patients qui prennent des médicaments hypolipidémiants, le jeûne devient important. Conclusion Être à jeun pour la détermination routinière des niveaux lipidiques est largement inutile et il est improbable que le jeûne influence la stratification du risque clinique chez le patient, tandis que la mesure sans être à jeun pourrait améliorer l’observance par le patient et sa sécurité.

  11. Occurrence and removal of pharmaceutical and hormone contaminants in rural wastewater treatment lagoons.

    PubMed

    Li, Xiaolin; Zheng, Wei; Kelly, Walton R

    2013-02-15

    Rural communities in the United States usually use a series of aerated lagoons to treat domestic wastewater. Effluents from these systems are typically discharged to receiving watersheds, which leads to a potential transfer of pharmaceuticals and personal care products (PPCPs) and steroid hormones from sanitary sewage to the environment. The primary objectives of this study are to identify and quantify PPCPs and steroid hormones in rural sewage treatment lagoons, to investigate the removal efficiency of these emerging contaminants in the treatment processes, and to monitor their occurrence in the surrounding watershed. In this study, a method has been developed to analyze thirteen PPCPs and eight steroid hormones in various water samples. Among all of the PPCPs considered, ten chemicals were detected in sewage influents, lagoon waters of different treatment stages, or effluents at concentrations in the ng/L to low μg/L range. Three hormones were observed in the influents at total concentrations as high as 164 ng/L, but no hormone residues were detected in the effluents. This indicates that the aerated lagoons may effectively remove hormone contaminants. With the exception of carbamazepine, removal rates for the other detected PPCPs were relatively high in the range of 88 to 100% in September with average air temperature equal to 20 °C. However, the removal efficiency of nine PPCPs in the rural wastewater treatment plant exhibited large temporal variability. The concentrations of PPCPs in the lagoon waters and effluents collected in November, with average air temperature equal to 4.4 °C, were 1-2 orders of magnitude higher than those samples collected in September. Occurrence of these PPCP contaminants in the surrounding watershed was also monitored. The discharge of effluents significantly elevated the PPCP concentrations in the receiving creek and increased their occurrence in the adjacent river.

  12. Differences in ichthyofauna feeding habits among lateral lagoons and the river channel in a large reservoir.

    PubMed

    Ferrareze, M; Nogueira, M G; Casatti, L

    2015-05-01

    In this study, we investigated differences in feeding habits of small-sized ichthyofauna among lateral lagoons and the river channel in a large reservoir. The study was performed in four lagoons and in one sampling site of the main channel in Rosana Reservoir, Paranapanema River, Brazil. The samples were taken in September and November of 2004 and in January, March, May, and August of 2005. Fish were sampled with a 7.5 m2 hand net. Five manual throws were made toward aquatic macrophytes stands. The sampling design favored the collection of small-sized fish fauna (juveniles/small-sized species). The stomach contents of 42 species were analyzed. A total of 183 different items were consumed by fish. These items were grouped in 11 food categories, which were used to classify fish into seven trophic guilds. Aquatic insects were consumed by 32 species and were the predominant feeding item. In the river, the most consumed items were aquatic insects, cladocerans, and phytoplankton, whereas in the lagoons aquatic insects, copepods, and cladocerans were the main items. By comparing each trophic guild, the number of insectivores, algivores, and zooplanktivores species was higher in the lagoons than in the river, and the opposite was found only for omnivore fish. Low niche width in all sites indicates high trophic specialization and low niche overlap between pairs of species. Fish assemblage in the lateral lagoons presents feeding habits distinct from those of the river species, indicating that the coexistence and high abundance of small-sized fish in the sampling sites are explained by their high feeding adaptability, which includes a tendency toward dietary specialization, low feeding overlap, and resource partitioning, along with different temporal resource uses.

  13. Temporal coherence among tropical coastal lagoons: a search for patterns and mechanisms.

    PubMed

    Caliman, A; Carneiro, L S; Santangelo, J M; Guariento, R D; Pires, A P F; Suhett, A L; Quesado, L B; Scofield, V; Fonte, E S; Lopes, P M; Sanches, L F; Azevedo, F D; Marinho, C C; Bozelli, R L; Esteves, F A; Farjalla, V F

    2010-10-01

    Temporal coherence (i.e., the degree of synchronicity of a given variable among ecological units within a predefined space) has been shown for several limnological features among temperate lakes, allowing predictions about the structure and function of ecosystems. However, there is little evidence of temporal coherence among tropical aquatic systems, where the climatic variability among seasons is less pronounced. Here, we used data from long-term monitoring of physical, chemical and biological variables to test the degree of temporal coherence among 18 tropical coastal lagoons. The water temperature and chlorophyll-a concentration had the highest and lowest temporal coherence among the lagoons, respectively, whereas the salinity and water colour had intermediate temporal coherence. The regional climactic factors were the main factors responsible for the coherence patterns in the water temperature and water colour, whereas the landscape position and morphometric characteristics explained much of the variation of the salinity and water colour among the lagoons. These results indicate that both local (lagoon morphometry) and regional (precipitation, air temperature) factors regulate the physical and chemical conditions of coastal lagoons by adjusting the terrestrial and marine subsidies at a landscape-scale. On the other hand, the chlorophyll-a concentration appears to be primarily regulated by specific local conditions resulting in a weak temporal coherence among the ecosystems. We concluded that temporal coherence in tropical ecosystems is possible, at least for some environmental features, and should be evaluated for other tropical ecosystems. Our results also reinforce that aquatic ecosystems should be studied more broadly to accomplish a full understanding of their structure and function.

  14. Diazotrophic bacterioplankton in a coral reef lagoon: phylogeny, diel nitrogenase expression and response to phosphate enrichment.

    PubMed

    Hewson, Ian; Moisander, Pia H; Morrison, Amanda E; Zehr, Jonathan P

    2007-05-01

    We investigated diazotrophic bacterioplankton assemblage composition in the Heron Reef lagoon (Great Barrier Reef, Australia) using culture-independent techniques targeting the nifH fragment of the nitrogenase gene. Seawater was collected at 3 h intervals over a period of 72 h (i.e. over diel as well as tidal cycles). An incubation experiment was also conducted to assess the impact of phosphate (PO(4)3*) availability on nifH expression patterns. DNA-based nifH libraries contained primarily sequences that were most similar to nifH from sediment, microbial mat and surface-associated microorganisms, with a few sequences that clustered with typical open ocean phylotypes. In contrast to genomic DNA sequences, libraries prepared from gene transcripts (mRNA amplified by reverse transcription-polymerase chain reaction) were entirely cyanobacterial and contained phylotypes similar to those observed in open ocean plankton. The abundance of Trichodesmium and two uncultured cyanobacterial phylotypes from previous studies (group A and group B) were studied by quantitative-polymerase chain reaction in the lagoon samples. These were detected as transcripts, but were not detected in genomic DNA. The gene transcript abundance of these phylotypes demonstrated variability over several diel cycles. The PO(4)3* enrichment experiment had a clearer pattern of gene expression over diel cycles than the lagoon sampling, however PO(4)3* additions did not result in enhanced transcript abundance relative to control incubations. The results suggest that a number of diazotrophs in bacterioplankton of the reef lagoon may originate from sediment, coral or beachrock surfaces, sloughing into plankton with the flooding tide. The presence of typical open ocean phylotype transcripts in lagoon bacterioplankton may indicate that they are an important component of the N cycle of the coral reef.

  15. Diuron tolerance and potential degradation by pelagic microbiomes in the Great Barrier Reef lagoon

    PubMed Central

    Pantos, Olga; Morgan, Thomas C.; Rich, Virginia; Tonin, Hemerson; Bourne, David G.; Mercurio, Philip; Negri, Andrew P.; Tyson, Gene W.

    2016-01-01

    Diuron is a herbicide commonly used in agricultural areas where excess application causes it to leach into rivers, reach sensitive marine environments like the Great Barrier Reef (GBR) lagoon and pose risks to marine life. To investigate the impact of diuron on whole prokaryotic communities that underpin the marine food web and are integral to coral reef health, GBR lagoon water was incubated with diuron at environmentally-relevant concentration (8 µg/L), and sequenced at specific time points over the following year. 16S rRNA gene amplicon profiling revealed no significant short- or long-term effect of diuron on microbiome structure. The relative abundance of prokaryotic phototrophs was not significantly altered by diuron, which suggests that they were largely tolerant at this concentration. Assembly of a metagenome derived from waters sampled at a similar location in the GBR lagoon did not reveal the presence of mutations in the cyanobacterial photosystem that could explain diuron tolerance. However, resident phages displayed several variants of this gene and could potentially play a role in tolerance acquisition. Slow biodegradation of diuron was reported in the incubation flasks, but no correlation with the relative abundance of heterotrophs was evident. Analysis of metagenomic reads supports the hypothesis that previously uncharacterized hydrolases carried by low-abundance species may mediate herbicide degradation in the GBR lagoon. Overall, this study offers evidence that pelagic phototrophs of the GBR lagoon may be more tolerant of diuron than other tropical organisms, and that heterotrophs in the microbial seed bank may have the potential to degrade diuron and alleviate local anthropogenic stresses to inshore GBR ecosystems. PMID:26989611

  16. Ecological implications of heavy metal concentrations in the sediments of Burullus Lagoon of Nile Delta, Egypt

    NASA Astrophysics Data System (ADS)

    Chen, Zhongyuan; Salem, Alaa; Xu, Zhuang; Zhang, Weiguo

    2010-02-01

    This paper examines the spatial and temporal distribution of heavy metals (Fe, Al, Cu, Zn, Mn, Cd, Pb and Ni) from three short sediment cores collected from Burullus lagoon of the Nile delta, Egypt. 210Pb and 137Cs measurement is applied to understand sedimentation rate and related chronology. Remarkably low isotopic activities and intensive bioturbation in the lagoonal sediments rendered age determination difficult. Samples with detectable 137Cs in the upper core sediments together with sediment lithology could help infer a sedimentation rate of about 2.0 mm yr -1, thereby indicating post-dam (after 1964) sedimentation of the upper 10-cm core sediments. Our results demonstrate that most heavy metals in the surficial sediments after normalization to Al decrease seaward, showing a function of distance to the sewerage outlet on the inland lake coast. Also, there is an upwardly increasing trend of normalized heavy metals, especially in the upper 10-cm core sediments. Relevancy analysis has identified Mn, Pb and Cd as the diagnostic heavy metals in Burullus lagoon, most likely derived from Tanta and Kafrelsheihk, the major downtowns in the central Nile delta plain, from where wastewaters are directly discharging into the lake via canal networks. Although Burullus lagoon is presently least affected by pollution as compared to other major lagoons of the Nile delta, the increasing quantities of diagnostic metals, especially Mn, are extremely toxic, as they are potentially linked to the risks of digestive issues and pancreatic cancer reportedly. The situation calls for a rational planning for sewerage treatment in the protected Burullus coast.

  17. Biogeochemical responses to nutrient inputs in a Cuban coastal lagoon: runoff, anthropogenic, and groundwater sources.

    PubMed

    González-De Zayas, R; Merino-Ibarra, M; Soto-Jiménez, M F; Castillo-Sandoval, F S

    2013-12-01

    Laguna Larga, a coastal lagoon in central Cuba, has been heavily altered by tourism infrastructure construction and sewage disposal. We hypothesize that this has decreased the circulation and caused eutrophication of the lagoon. To assess this, 12 bimonthly samplings were carried out in 2007-2008. Temperature, salinity, oxygen, nutrients and nitrogen, and phosphorous fractions (inorganic, organic, and total) were determined. Water and salt budgets, as well as biogeochemical fluxes of nitrogen and phosphorus were calculated using the LOICZ budget model for the three sections of the lagoon identified by morphological constrains and salinity patterns. Laguna Larga is a choked lagoon with restricted water circulation, low exchange, and high residence times that vary significantly along its sections. Residence time was estimated to be 0.1-0.7 years for the inner section and 1-9 days for the outer one. High levels of total nitrogen (annual means 126-137 μM, peaks up to 475 μM) and phosphorus (2.5-4.4 μM, peaks up to 14.5 μM) are evidence of eutrophication of Laguna Larga. During 2007, an average precipitation year, Laguna Larga exported water (703 m(3) d(-1)) and was a source of nitrogen (9.026 mmol m(-2) d(-1)) and phosphorus (0.112 mmol m(-2) d(-1)) to the adjacent sea. δ(15)N determinations in the seagrass Thalassia testudinum (-1.83 to +3.02 ‰) differed significantly between sites in the lagoon and offshore reference sites located W of the inlet, but were similar to those located E of the inlet. δ(15)N determinations in the seaweed Penicillus dumetosus (+1.02 to +4.2) did not show significant differences.

  18. Removal of selected pharmaceuticals, personal care products and artificial sweetener in an aerated sewage lagoon.

    PubMed

    Hoque, M Ehsanul; Cloutier, Frédéric; Arcieri, Carlo; McInnes, Mark; Sultana, Tamanna; Murray, Craig; Vanrolleghem, Peter A; Metcalfe, Chris D

    2014-07-15

    A sewage lagoon serving the small municipality of Lakefield in Ontario, Canada was monitored in the summer, fall and winter to determine removals of carbamazepine, trimethoprim, sulfamethoxazole, ibuprofen, gemfibrozil, triclosan, sucralose, HHCB and AHTN. Concentrations of these compounds in untreated and treated wastewater were estimated by deploying POCIS and SPMD passive samplers in the sewage lagoon. Passive samplers were also deployed at several points upstream and downstream of the point of discharge from the lagoon into the Otonabee River. LC-MS/MS and GC-MS were utilized to determine the concentrations of pharmaceuticals and personal care products (PPCPs) and sucralose, an artificial sweetener. Among PPCPs sampled by POCIS, the highest estimated concentration in untreated wastewater was ibuprofen sampled during the fall, at an estimated concentration of 60.3 ng/L. The estimated average concentration of sucralose was 13.6 ng/L in the untreated wastewaters. Triclosan, HHCB and AHTN in SPMDs were highest during fall season, at 30, 1677 and 109 ng/L, respectively. For all compounds except gemfibrozil, carbamazepine and sucralose, removals were highest in the summer (83.0 to 98.8%) relative to removals in the fall (48.4 to 91.4%) and winter (14.0 to 78.3%). Finally, the estimated concentrations of carbamazepine, sulfamethoxazole, triclosan and HHCB were compared with predicted values obtained through application of the WEST® modeling tool, with a new model based on the River Water Quality Model No. 1 and extended with dynamic mass balances describing the fate of chemicals of emerging concern subject to a variety of removal pathways. The model was able to adequately predict the fate of these four compounds in the lagoon in summer and winter, but the model overestimated removals of three of the four test compounds in the fall sampling period. This lagoon was as effective at removing PPCPs as many conventional WWTPs, but removals were better during the summer.

  19. Liquid and atmospheric ammonia concentrations from a dairy lagoon during an aeration experiment

    NASA Astrophysics Data System (ADS)

    Rumburg, Brian; Neger, Manjit; Mount, George H.; Yonge, David; Filipy, Jenny; Swain, John; Kincaid, Ron; Johnson, Kristen

    Ammonia emissions from agriculture are an environmental and human health concern, and there is increasing pressure to reduce emissions. Animal agriculture is the largest global source of ammonia emissions and on a per cow basis dairy operations are the largest emitters. The storage and disposal of the dairy waste is one area where emissions can be reduced, aerobic biological treatment of wastewater being a common and effective way of reducing ammonia emissions. An aeration experiment in a dairy lagoon with two commercial aerators was performed for 1 month. Liquid concentrations of ammonia, total nitrogen, nitrite and nitrate were monitored before, during and after the experiment and atmospheric ammonia was measured downwind of the lagoon using a short-path differential optical absorption spectroscopy (DOAS) instrument with 1 ppbv sensitivity. No changes in either liquid or atmospheric ammonia concentrations were detected throughout the experiment, and neither dissolved oxygen, nitrite nor nitrate could be detected in the lagoon at any time. The average ammonia concentration at 10 sampling sites in the lagoon at a depth of 0.15 m was 650 mg l -1 and at 0.90 m it was 700 mg l -1 NH 3-N. The average atmospheric ammonia concentration 50 m downwind was about 300 ppbv. The 0.90 m depth total nitrogen concentrations and total and volatile solids concentrations decreased during the experiment due to some mixing of the lagoon but the 0.15 m depth concentrations did not decrease indicating that the aerators were not strong enough to mix the sludge off the bottom into the whole water column.

  20. Evaluation of some heavy metal loading in the Kpeshi lagoon, Ghana

    NASA Astrophysics Data System (ADS)

    Fianko, Joseph R.; Laar, Cynthia; Osei, Juilet; Anim, Alfred K.; Gibrilla, Abass; Adomako, Dickson

    2013-03-01

    A study was carried out on the Kpeshi lagoon to evaluate the relative contributions of some heavy metals (Na, k, Ca, K, Fe, Mn, Ni, Cr, Cd, Al, Pb) on the current state of the Kpeshi lagoon. The lagoon water was sampled along with some fish samples. Water pH, electrical conductivity and total dissolved salts were measured in situ whilst Na and K were measured using flame emission spectrometry. Heavy metals (iron, manganese, nickel, aluminium, chromium, lead and cadmium) in both water and fish samples were analyzed using atomic absorption spectrometry. Measured pH values ranged between 6.60 and 7.87, a mean conductivity and total dissolved salts of 87.31 ± 19.14 μS/cm and 38.4 ± 8.43 mg/L, respectively. Nutrient and organic matter were among the frequent source of pollution in the lagoon with mean sulphate, phosphate and nitrate concentrations of 190 ± 108.84, 1.62 ± 0.49 and 0.89 ± 0.26 mg/L, respectively. Iron and aluminium in the lagoon water measured the highest concentration of 13.2 ± 3.47 and 13.6 ± 4.29 mg/L, respectively. Fish samples however revealed very high concentrations of calcium and potassium measuring 15,709 ± 75.35 and 5,949.49 ± 87.30 mg/kg, respectively. Sodium and aluminium also revealed relatively high concentrations: 3,775.70 ± 24.80 and 708.47 ± 4.95 mg/kg, respectively. Notably, sites closer to settlement community (Teshie Township, e.g. S1, S2, S3 and S4) and the hospitality industries (i.e. dotted hotels, e.g. S7) appeared to be relatively more contaminated.

  1. State-of-the-lagoon reports as vehicles of cross-disciplinary integration.

    PubMed

    Zaucha, Jacek; Davoudi, Simin; Slob, Adriaan; Bouma, Geiske; van Meerkerk, Ingmar; Oen, Amy Mp; Breedveld, Gijs D

    2016-10-01

    An integrative approach across disciplines is needed for sustainable lagoon and estuary management as identified by integrated coastal zone management. The ARCH research project (Architecture and roadmap to manage multiple pressures on lagoons) has taken initial steps to overcome the boundaries between disciplines and focus on cross-disciplinary integration by addressing the driving forces, challenges, and problems at various case study sites. A model was developed as a boundary-spanning activity to produce joint knowledge and understanding. The backbone of the model is formed by the interaction between the natural and human systems, including economy and governance-based subsystems. The model was used to create state-of-the-lagoon reports for 10 case study sites (lagoons and estuarine coastal areas), with a geographical distribution covering all major seas surrounding Europe. The reports functioned as boundary objects to build joint knowledge. The experiences related to the framing of the model and its subsequent implementation at the case study sites have resulted in key recommendations on how to address the challenges of cross-disciplinary work required for the proper management of complex social-ecological systems such as lagoons, estuarine areas, and other land-sea regions. Cross-disciplinary integration is initially resource intensive and time consuming; one should set aside the required resources and invest efforts at the forefront. It is crucial to create engagement among the group of researchers by focusing on a joint, appealing overall concept that will stimulate cross-sectoral thinking and focusing on the identified problems as a link between collected evidence and future management needs. Different methods for collecting evidence should be applied including both quantitative (jointly agreed indicators) and qualitative (narratives) information. Cross-disciplinary integration is facilitated by functional boundary objects. Integration offers important

  2. Metazoan parasites of fishes from the Celestun coastal lagoon, Yucatan, Mexico.

    PubMed

    Sosa-Medina, Trinidad; Vidal-Martínez, Víctor M; Aguirre-Macedo, M Leopoldina

    2015-08-31

    The aims of this study were to produce a checklist of the metazoan parasites of fishes from the Celestun coastal lagoon and to determine the degree of faunal similarity among the fishes based on the metazoan parasites they share. A checklist was prepared including all available records (1996-2014) of parasites of marine, brackish water and freshwater fishes of the area. All of these data were included in a presence/absence database and used to determine similarity via Jaccard's index. The results indicate the presence of 62 metazoan parasite species infecting 22 fish species. The number of metazoan parasite species found in the fishes from the Celestún lagoon is apparently the highest reported worldwide for a tropical coastal lagoon. The parasites included 12 species of adult digeneans, 27 digeneans in the metacercarial stage, 6 monogeneans, 3 metacestodes, 9 nematodes, 2 acanthocephalans, 2 crustaceans and 1 annelid. Forty parasite species were autogenic and 23 were allogenic and 1 unknown. The overall similarity among all of the species of fish with respect to the metazoan parasites they share was low (0.08 ± 0.12), with few similarity values above 0.4 being obtained. This low similarity was due primarily to the presence of suites of parasites exclusive to specific species of fish. The autogenic component of the parasite fauna (40 species) dominated the allogenic component (21 species). The most likely explanation for the large number of fish parasites found at Celestún is the good environmental condition of the lagoon, which allows the completion of parasite life cycles and free circulation of euryhaline fishes from the marine environment bringing marine parasites into the lagoon.

  3. Diuron tolerance and potential degradation by pelagic microbiomes in the Great Barrier Reef lagoon.

    PubMed

    Angly, Florent E; Pantos, Olga; Morgan, Thomas C; Rich, Virginia; Tonin, Hemerson; Bourne, David G; Mercurio, Philip; Negri, Andrew P; Tyson, Gene W

    2016-01-01

    Diuron is a herbicide commonly used in agricultural areas where excess application causes it to leach into rivers, reach sensitive marine environments like the Great Barrier Reef (GBR) lagoon and pose risks to marine life. To investigate the impact of diuron on whole prokaryotic communities that underpin the marine food web and are integral to coral reef health, GBR lagoon water was incubated with diuron at environmentally-relevant concentration (8 µg/L), and sequenced at specific time points over the following year. 16S rRNA gene amplicon profiling revealed no significant short- or long-term effect of diuron on microbiome structure. The relative abundance of prokaryotic phototrophs was not significantly altered by diuron, which suggests that they were largely tolerant at this concentration. Assembly of a metagenome derived from waters sampled at a similar location in the GBR lagoon did not reveal the presence of mutations in the cyanobacterial photosystem that could explain diuron tolerance. However, resident phages displayed several variants of this gene and could potentially play a role in tolerance acquisition. Slow biodegradation of diuron was reported in the incubation flasks, but no correlation with the relative abundance of heterotrophs was evident. Analysis of metagenomic reads supports the hypothesis that previously uncharacterized hydrolases carried by low-abundance species may mediate herbicide degradation in the GBR lagoon. Overall, this study offers evidence that pelagic phototrophs of the GBR lagoon may be more tolerant of diuron than other tropical organisms, and that heterotrophs in the microbial seed bank may have the potential to degrade diuron and alleviate local anthropogenic stresses to inshore GBR ecosystems.

  4. He-Ne laser extravascular irradiation therapy

    NASA Astrophysics Data System (ADS)

    Chen, Rong; Chen, Huifang; Xie, Shusen; Chen, Yanjiao; Zhang, Yanrong

    2000-10-01

    Based on the study of tissue optics related with the laser irradiation blood therapy, a new treatment method, extravascular low-level laser irradiation therapy (ELLLI) is developed. The veins of 30 patients with cerebrovascular disease combined with diabetes, asthma were treated by He-Ne laser (632.8nm, 25mW) which was delivered by an optics fiber. The fiber was outside the patient's skin and the laser irradiated on the blood vessel perpendicularly. The therapy time was 60 minutes each time and about 7-10 times a course of the treatment. The values of blood sugar, blood- fat and hemorrheology were measured as the effective indexes. After the treatment the effective indexes and the symptoms of the patients were all improved. With the advantages of simplicity and safety (no medical infection), laser extravascular irradiation therapy is likely to be a new medical method for heart brain and other diseases.

  5. He-Ne laser treatment on menorrhagia

    NASA Astrophysics Data System (ADS)

    Ding, Ai-Hua

    1993-03-01

    By using He-Ne laser treatment, 84.7 - 91.1% of patients with menorrhagia, a common symptom of multiple gynecological diseases, are treated effectively. After laser irradiation, the amount of vaginal bleeding was reduced 47.1% on average. It has been proven that low-energy laser is an effective non-traumatic, painless, and easily acceptable new physical method in patients with menorrhagia. To study the mechanisms of efficiency, the quantitative determination of PGE2, PGF2(alpha ), 6-Keto-PGF1(alpha ), TXB2 in endometrium and blood flow before and after treatment were carried out. The results suggest that the effectiveness may be due to the recovery regulation of local uterine PGS level.

  6. Active Eruptions in the NE Lau Basin

    NASA Astrophysics Data System (ADS)

    Resing, J. A.; Embley, R. W.

    2009-12-01

    NE Lau Response Team: K Rubin, E Baker, J Lupton, M Lilley, T Shank, S Merle, R Dziak, T Collasius (Jason 2 Expedition Leader), N Buck, T Baumberger, D Butterfield, D Clague, D Conlin, J Cowen, R Davis, L Evans, J Huber, M Keith, N Keller, P Michael, E Podowski, A-L Reysenbach, K Roe, H Thomas, S Walker. During a May 2009 cruise to W Mata volcano in the NE Lau Basin, we made the first observations of an active eruption on the deep-sea floor. The cruise was organized after volcanic activity was detected at two sites (W Mata volcano and NE Lau Spreading Center, NELSC) during a Nov. 2008 NOAA-PMEL expedition. At that time, both sites had elevated H2 concentrations and volcaniclastic shards in the hydrothermal plumes. Moored hydrophone data since Jan 2009 indicate that the activity at W Mata has been continuous between these expeditions. Results of our cruise and other work suggest that the NE Lau Basin hosts an unusually high level of magmatic activity, making it an ideal location to study the effects of magmatic processes on hydrothermal activity and associated ecosystems. W Mata was visited with 5 ROV Jason 2 dives and 2 dives with the MBARI autonomous mapping vehicle in May 2009. It was actively erupting at the 1200 m deep summit during each, so a hydrophone was deployed locally to collect acoustic data. Ship and shore-based analysis of HD video, molten lava, rocks, sediments, hot spring waters, and micro- and macro biological specimens collected by Jason 2 have provided a wealth of data. The eruption itself was characterized by extrusion of red, molten lava, extensive degassing, formation of large magma bubbles, explosive pyroclast ejection, and the active extrusion of pillow lavas. The erupting magmas are boninite, a relatively rare magma type found only at convergent margins. The hydrothermal fluids are generally acidic and all diffuse fluids collected were microbially active, even those at pH <3. W Mata was host to shrimp similar to those found at several other

  7. MiniBooNE Oscillation Results 2011

    SciTech Connect

    Djurcic, Zelimir

    2012-01-01

    The MiniBooNE neutrino oscillation search experiment at Fermilab has recently updated results from a search for {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} oscillations, using a data sample corresponding to 8.58 x 10{sup 20} protons on target in anti-neutrino mode. This high statistics result represent an increase in statistics of 52% compared to result published in 2010. An excess of 57.7 {+-} 28.5 events is observed in the energy range 200 MeV < E{sub {nu}} < 3000 MeV. The data favor LSND-like {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} oscillations over a background only hypothesis at 91.1% confidence level in the energy range 475 < E{sub {nu}} < 3000 MeV.

  8. Phytoplankton dynamics in the NE subarctic Pacific

    NASA Astrophysics Data System (ADS)

    Boyd, Philip; Harrison, P. J.

    1999-11-01

    Ocean Station Papa (OSP, 50°N 145°W) in the NE subarctic Pacific is characterised as high nitrate low chlorophyll (HNLC). However, little is known about the spatial extent of these HNLC waters or the phytoplankton dynamics on the basin scale. Algal biomass, production and size-structure data are presented from winter, spring and summer between 1992 and 1997 for five stations ranging from coastal to open-ocean conditions. The inshore stations (P04-P16) are characterised by the classical seasonal cycle of spring and late summer blooms (production >3 g C m -2 d -1), diatoms are not Fe-stressed, and growth rate is probably controlled by macronutrient supply. The fate of the phytoplankton is likely sedimentation by diatom-dominated spring blooms, with a pelagic recycling system predominating at other times. The offshore stations (P20/OSP) display low seasonality in biomass and production (OSP, mean winter production 0.3 g C m -2 d -1, mean spring/summer production 0.85 g C m -2 d -1), and are dominated by small algal cells. Low Fe availability prevents the occurrence of diatom blooms observed inshore. The main fate of phytoplankton is probably recycling through the microbial food web, with relatively low sedimentation compared to inshore. However, the supply of macro- and micro-nutrients to the coastal and open ocean, respectively, may vary between years. Variability in macro-nutrient supply to the coastal ocean may result in decreased winter reserve nitrate, summer nitrate limitation, subsequent floristic shifts towards small cells, and reduced primary production. Offshore, higher diatom abundances are occasionally observed, perhaps indicating episodic Fe supply. The two distinct oceanic regimes have different phytoplankton dynamics resulting in different seasonality, community structure and fate of algal carbon. These differences will strongly influence the biogeochemical signatures of the coastal and open-oceanic NE subarctic Pacific.

  9. Discovery of a Circumstellar Disk in the Lagoon Nebula

    NASA Astrophysics Data System (ADS)

    1997-04-01

    Circumstellar disks of gas and dust play a crucial role in the formation of stars and planets. Until now, high-resolution images of such disks around young stars within the Orion Nebula obtained with the Hubble Space Telescope (HST) constituted the most direct proof of their existence. Now, another circumstellar disk has been detected around a star in the Lagoon Nebula - also known as Messier 8 (M8) , a giant complex of interstellar gas and dust with many young stars in the southern constellation of Sagittarius and four times more distant than the Orion Nebula. The observations were carried out by an international team of scientists led by Bringfried Stecklum (Thüringer Landessternwarte, Tautenburg, Germany) [1] who used telescopes located at the ESO La Silla observatory and also observations from the HST archive. These new results are paving the road towards exciting research programmes on star formation which will become possible with the ESO Very Large Telescope. The harsh environment of circumstellar disks The existence of circumstellar disks has been inferred from indirect measurements of young stellar objects, such as the spectral energy distribution, the analysis of the profiles of individual spectral lines and measurements of the polarisation of the emitted light [2]. Impressive images of such disks in the Orion Nebula, known as proplyds (PROto-PLanetarY DiskS), have been obtained by the HST during the recent years. They have confirmed the interpretation of previous ground-based emission-line observations and mapping by radio telescopes. Moreover, they demonstrated that those disks which are located close to hot and massive stars are subject to heating caused by the intense radiation from these stars. Subsequently, the disks evaporate releasing neutral gas which streams off. During this process, shock fronts (regions with increased density) with tails of ionised gas result at a certain distance between the disk and the hot star. These objects appear on

  10. A Continuation of Base-Line Studies for Environmentally Monitoring Space Transportation Systems at John F. Kennedy Space Center. Volume 3, Part 1: Ichthyological Survey of Lagoonal Waters. [Indian River lagoon system

    NASA Technical Reports Server (NTRS)

    Snelson, F. F., Jr.

    1980-01-01

    Ichthyological species in the Indian River lagoonal system likely to be affected by NASA's aerospace activities at the Kennedy Space Center were surveyed. The importance of the fish found to inhabit the waters in the area is analyzed.

  11. Post-glacial sea-level history for NE Ireland (Belfast Lough) based on offshore evidence

    NASA Astrophysics Data System (ADS)

    Quinn, R.; Plets, R. M.; Callard, L.; Cooper, A.; Long, A. J.; Belknap, D. F.; Edwards, R.; Jackson, D.; Kelley, J. T.; Long, D.; Milne, G. A.; Monteys, X.

    2013-12-01

    Glacio-isostatic adjustment (GIA) models suggest a complex relative sea-level (RSL) pattern around the Irish Sea Basin after the Last Glacial Maximum (LGM), with modelled sea-level lowstands ranging from -12 m in the north to greater than -60 m in the south of the Basin. However, these GIA models are poorly constrained by observational data offshore. Belfast Lough, on the NE coast of Ireland, is one of seven sites chosen to investigate this complex RSL history as part of the project ';Late Glacial Sea level minima in the Western British Isles' (NERC NE/H024301/1). Belfast Lough was chosen as one of the candidate sites on the basis of location (at the northern end of the Irish Sea Basin), sedimentary environment (grossly depositional) and the fact that the lowstand predicted for the Belfast Lough area by a recent version of the GIA model (-16.5 m) differs significantly from the (limited) extant observational data, which interprets the lowstand at -30 m. In 2011 and 2012 we gathered new multi-beam echo-sounder data, >200 km trackline pinger- and boomer- seismic reflection data and 46 vibrocores in Belfast Lough. Radiocarbon dating and palaeoenvironmental analysis are used to constrain the interpretation of the seismic and sediment data. Five seismo-stratigraphic units are interpreted, with a distinct erosional surface between U3 and U4 interpreted as a transgressive surface associated with sea level rise post-dating a RSL lowstand. Foraminiferal evidence indicates an increase in marine species (from lagoonal/estuarine to fully marine) from U4 to U5. Integration of the seismic and core data indicate an erosional event prior to 12.7 cal yr BP resulting in a planated surface in the inner Lough and wave-eroded drumlins at the mouth of the Lough between -15 and -22 m, interpreted as a possible slowstand. On the basis of seismic evidence in the outer Lough, an as yet undated lowstand at -42 m is tentatively interpreted to pre-date this stillstand. These results will be

  12. Post-glacial sea-level history for NE Ireland (Belfast Lough) based on offshore evidence

    NASA Astrophysics Data System (ADS)

    Quinn, Rory; Plets, Ruth; Callard, Louise; Cooper, Andrew; Antony, Long; Daniel, Belknap; Robin, Edwards; Derek, Jackson; Joseph, Kelley; David, Long; Glenn, Milne; Xavier, Monteys

    2014-05-01

    Glacio-isostatic adjustment (GIA) models suggest a complex relative sea-level (RSL) pattern around the Irish Sea Basin after the Last Glacial Maximum (LGM), with modelled sea-level lowstands ranging from -12 m in the north to greater than -60 m in the south of the Basin. However, these GIA models are poorly constrained by observational data offshore. Belfast Lough, on the NE coast of Ireland, is one of seven sites chosen to investigate this complex RSL history as part of the project 'Late Glacial Sea level minima in the Western British Isles' (NERC NE/H024301/1). Belfast Lough was chosen as one of the candidate sites on the basis of location (at the northern end of the Irish Sea Basin), sedimentary environment (grossly depositional) and the fact that the lowstand predicted for the Belfast Lough area by a recent version of the GIA model (-16.5 m) differs significantly from the (limited) extant observational data, which interprets the lowstand at -30 m. In 2011 and 2012 we gathered new multi-beam echo-sounder data, >200 km trackline pinger- and boomer- seismic reflection data and 46 vibrocores in Belfast Lough. Radiocarbon dating and palaeoenvironmental analysis are used to constrain the interpretation of the seismic and sediment data. Five seismo-stratigraphic units are interpreted, with a distinct erosional surface between U3 and U4 interpreted as a transgressive surface associated with sea level rise post-dating a RSL lowstand. Foraminiferal evidence indicates an increase in marine species (from lagoonal/estuarine to fully marine) from U4 to U5. Integration of the seismic and core data indicate an erosional event prior to 12.7 cal yr BP resulting in a planated surface in the inner Lough and wave-eroded drumlins at the mouth of the Lough between -15 and -22 m, interpreted as a possible slowstand. On the basis of seismic evidence in the outer Lough, an as yet undated lowstand at -42 m is tentatively interpreted to pre-date this stillstand. These results will be used

  13. Intruder configurations in the ground state of 30Ne

    NASA Astrophysics Data System (ADS)

    Liu, H. N.; Lee, J.; Doornenbal, P.; Scheit, H.; Takeuchi, S.; Aoi, N.; Li, K. A.; Matsushita, M.; Steppenbeck, D.; Wang, H.; Baba, H.; Ideguchi, E.; Kobayashi, N.; Kondo, Y.; Lee, G.; Michimasa, S.; Motobayashi, T.; Poves, A.; Sakurai, H.; Takechi, M.; Togano, Y.; Tostevin, J. A.; Utsuno, Y.

    2017-04-01

    We report on the first detailed study of intruder configurations in the ground state of 30Ne by means of the 12C(30Ne, 29Ne+γ)X one-neutron knockout reaction at 228 MeV/nucleon. Using a combined analysis of individual parallel momentum distributions and partial cross sections we find: (a) comparable p- and d-wave removal strength to 29Ne final states with excitation energies below 200 keV, and (b) significant p-wave removal strength to the 620 keV state of 29Ne, and (c) no evidence for f-wave intruder strength leading to bound 29Ne final states. The SDPF-U-MIX shell model calculation in the sd- pf model space provides a better overall agreement with the measured energy levels of 29Ne and the fp-intruder amplitudes in 30Ne than the SDPF-M prediction, suggesting that the refinement of the sd- pf cross shell interaction and extension of the model space to include the 2p1/2 and 1f5/2 levels are important for understanding the island of inversion.

  14. 78 FR 67297 - Establishment of Class E Airspace; Curtis, NE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-12

    ... Federal Aviation Administration 14 CFR Part 71 Establishment of Class E Airspace; Curtis, NE AGENCY... airspace at Curtis, NE. Controlled airspace is necessary to accommodate new Area Navigation (RNAV) Standard Instrument Approach Procedures at Curtis Municipal Airport. The FAA is taking this action to enhance...

  15. 78 FR 41289 - Amendment of Class E Airspace; Ogallala, NE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-10

    ... Federal Aviation Administration 14 CFR Part 71 Amendment of Class E Airspace; Ogallala, NE AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action amends Class E airspace at... Register a notice of proposed rulemaking (NPRM) to amend Class E airspace for the Ogallala, NE.,...

  16. 75 FR 12166 - Class E Airspace; Beatrice, NE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-15

    ... Federal Aviation Administration 14 CFR Part 71 Class E Airspace; Beatrice, NE AGENCY: Federal Aviation... Class E airspace at Beatrice, NE. Decommissioning of the Shaw non-directional beacon (NDB) at Beatrice... amending Class E airspace extending upward from 700 feet above the surface for standard instrument...

  17. 76 FR 16530 - Establishment of Class E Airspace; Creighton, NE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-24

    ... Federal Aviation Administration 14 CFR Part 71 Establishment of Class E Airspace; Creighton, NE AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action establishes Class E... Federal Register a notice of proposed rulemaking to establish Class E airspace for Creighton, NE,...

  18. Addendum to the MiniBooNE Run Plab. MinneBooNE Physics in 2006

    SciTech Connect

    Aguilar-Arevalo, A. A.

    2004-11-02

    The primary physics goal of Mini BooNE is to confirm or rule out the LSND vμ→ve oscilliation observation with high significance. In the 2003 Run Plan document presented to the PAC, we outlined the need for 1 X 1021 protons on target (POT) to achieve this goal. In this document, we present an addendum to our run plan for fiscal year 2006 (FY2006).

  19. Preliminar Performance Assessment of NeQuick2-Plas Model

    NASA Astrophysics Data System (ADS)

    Migoya Orue, Yenca; Gulyaeva, Tamara; Nava, Bruno; Radicella, Sandro M.

    NeQuick is a semi-empirical model that describes spatial and temporal variations of the ionospheric electron density at global scale. It was jointly developed by the Aeronomy and Radiopropagation Laboratory of the Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy and the Institute for Geophysics, Astrophysics and Meteorology of the University of Graz, Austria. The model is able to calculate the electron concentration at any given location in the ionosphere as well as the total electron content (TEC) along any ground-to-satellite ray-path. One of the recent major changes introduced in the NeQuick2 model is the integration of the plasmasphere formulation of IRI-Plas that gave origin to the NeQuick-Plas. The plasmasphere extension of IRI, IRI-Plas, is an empirical model derived from many years of measurements designed to represent typical ionospheric conditions as a function of geomagnetic and solar activity. For the smooth fitting of the NeQuick and plasmasphere models, the half-peak density point, h0.5p is searched iteratively from NeQuick topside electron density profile. The present study uses median values of IGS combined global vertical TEC maps as reference to be compared with NeQuick 2 and NeQuick-Plas models. Representative months of years of high, moderate and low solar activity have been utilized. The preliminary results indicate an improvement of the NeQuick 2 -Plas with respect to NeQuick 2 especially during periods of high and moderate solar activity as indicated by the average and standard deviation of the TEC error distributions (e.g. IGS-NeQ2 mean is -9.73, standard deviation is 5.6 while IGS-NePlas mean is 2.87, with a standard deviation of 4.8 for October 2000; IGS-NeQ2 mean is -5.28, standard deviation is 0.37 while IGS-NeQ-Plas mean is 1.25, standard deviation of 0.49 for Jul 2003). During low solar activity (year 2008), instead, there is a slight tendency of NeQuick-Plas to overestimate TEC values and so increase the

  20. Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia) in Two Contrasting Lagoons in French Polynesia.

    PubMed

    Van Wynsberge, Simon; Andréfouët, Serge; Gaertner-Mazouni, Nabila; Wabnitz, Colette C C; Menoud, Mathilde; Le Moullac, Gilles; Levy, Peva; Gilbert, Antoine; Remoissenet, Georges

    2017-01-01

    Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems.

  1. Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia) in Two Contrasting Lagoons in French Polynesia

    PubMed Central

    Van Wynsberge, Simon; Andréfouët, Serge; Gaertner-Mazouni, Nabila; Wabnitz, Colette C. C.; Menoud, Mathilde; Le Moullac, Gilles; Levy, Peva; Gilbert, Antoine; Remoissenet, Georges

    2017-01-01

    Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems. PMID:28118406

  2. Photoionization and Recombination of ne IV and Excitation of NeV in Nebular Plasmas

    NASA Astrophysics Data System (ADS)

    Nahar, Sultana N.; Palay, Ethan; Pradhan, Anil K.

    2013-06-01

    %TEXT OF YOUR ABSTRACT The inverse processes of photoionization and electron-ion recombination are dominant in photoionized astrophysical plasmas. They determine the ionization fractions in photoionization equilibrium, physical conditions, and chemical abundances. We employ the unified theory of electron-ion recombination to study photoionization of Ne IV in photoionized nebulae. That leads to the production of Ne V and spectral emission of forbidden optical and mid-infrared [Ne V] lines via collisional excitation. These lines are prominent in the observations made by infrared space observatories SPITZER, SOFIA, and HERSCHEL. The unified method for electronic recombination provides self-consistent data for photoionization and recombination that is necessary to eliminate uncertainties in the determination of ionization fractions. To wit: Precise abundance of neon in the Sun is unknown owing to lack of accurate atomic data. A 20-level wave function expansion is used for the calculations of photoionization, recombination, and collisional excitation employing the relativistic Breit-Pauli R-matrix method in the close coupling approximation. We find and delineate extensive resonance structures at low energies that considerably enhance the effective cross sections and rates in astrophysical sources. Acknowledgement: Partially supported by DOE and NSF. Computational work was carried out at the Ohio Supercomputer Center

  3. Wetting transitions of Ne on alkali metal surfaces

    NASA Astrophysics Data System (ADS)

    Bojan, M. J.; Cole, M. W.; Steele, W. A.

    1997-03-01

    In relation to the Ne-Ne interatomic potential well depth, the adsorption potential of Ne on Cs is weaker than that of any other simple gas on any other surface. Hence the wetting temperature is expected to be higher (relative to the critical temperature) than that for any other known adsorption system. This expectation, based on a simple energy/entropy balance argument(E. Cheng, M. W. Cole, W. F. Saam and J. Treiner, Phys. Rev. B48,18214 (1993)) has been borne out in recent experiments of Hess et al(G. B. Hess, M. J. Sabatini and M. H. W. Chan,submitted to Phys. Rev.). We report here the results of grand canonical Monte Carlo simulations which find the simple argument to be qualitatively accurate. Our results imply a prewetting transition for Ne on Li and complete nonwetting of Ne on Cs. The case of a Rb surface is under investigation.

  4. Stone Age settlement and Holocene water level changes of the Baltic Sea in the Torvajoe Basin area, Narva-Luga Klint Bay, NE Estonia

    NASA Astrophysics Data System (ADS)

    Raig, Hanna; Rosentau, Alar; Muru, Merle; Risberg, Jan

    2014-05-01

    The Tõrvajõe basin is located in NE Estonia in the southern part of the Narva-Luga Klint Bay, that is characterized by slow post-glacial isostatic uplift (about 0-1mm/yr) and slowly undulating low topography. Post-glacial changes of the water-level of the Baltic Sea have at times flooded the area, and at times, it has emerged as terrestrial land. In addition to a complex geological development, the surroundings of the Tõrvajõe basin are interesting from the archaeological point of view because of abundant archaeological findings in the area, of which the oldest (c 8.1 cal ka BP) from the Mesolithic period and the majority, indicating very intense habitation (c 7.1-5.5 cal ka BP), from the Neolithic period. Development of the Tőrvajőe basin area during the period of Stone Age settlement (c 8.1-5.5 cal. ka BP) is studied with multiple geological and archaeological proxies. Sediments are described by lithostratigraphical methods, loss-on-ignition. AMS radiocarbon dates are used to date events and create an age-depth model. Environment is described by pollen analyses and water environment by siliceous microfossil analyses. Palaeogeographical reconstructions for time slices of interest are created to illustrate Stone Age settlement pattern and changes of the coastline and landscape over time. The aim of this interdisciplinary study is to investigate and associate palaeoenvironmental conditions and water-level changes with Stone Age settlement pattern in the Tőrvajőe area. Results show four developmental stages in the post-glacial history of the basin: Ancylus Lake lagoon, mire, lagoon during the Litorina Sea and mire. During the Ancylus Lake transgression at about 10.8-10.2 cal. ka BP a spit started to form north of the basin and a lagoon evolved behind it. Following the Ancylus Lake regression river activity and formation of palaeosoil and fen peat took place. Due to the Litorina Sea transgression, that was initially slower but accelerated around 7.8-7.6 cal ka

  5. Effect of climate change and mollusc invasion on eutrophication and algae blooms in the lagoon ecosystems of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Aleksandrov, Sergei; Gorbunova, Julia; Rudinskaya, Lilia

    2015-04-01

    Coastal lagoons are most vulnerable to impacts of natural environmental and anthropogenic factors. The Curonian Lagoon and Vistula Lagoon are the largest coastal lagoons of the Baltic Sea, relating to the most highly productive water bodies of Europe. The Curonian Lagoon is choke mostly freshwater lagoon, while the Vistula Lagoon is restricted brackish water lagoon. In the last decades the nutrients loading changes, warming trend and biological invasions are observed. The researches (chlorophyll, primary production, nutrients, phytoplankton, benthos, etc) were carried out monthly since 1991 to 2014. The database includes 1600 stations in the Curonian Lagoon, 1650 stations in the Vistula Lagoon. Eutrophication and algae blooms are most important problems. Multiple reductions of nutrients loading from the watershed area in 1990s did not result in considerable improvement of the ecological situation in the lagoons. The Curonian Lagoon may be characterized as hypertrophic water body with "poor" water quality. Climate change in 1990s-2000s combined with other factors (freshwater, slow-flow exchange, high nutrients concentrations) creates conditions for Cyanobacteria "hyperblooms". Hyperbloom of Cyanophyta (average for the growing season Chl > 100 μg/l) were observed during 4 years in 1990s and 7 years in 2000s. The summer water temperature is the key environmental factor determining the seasonal and long-term variability of the primary production and algae blooms. Mean annual primary production in 2010-2014 (600 gC·m-2·year-1) is considerable higher, than in the middle of 1970s (300 gC·m-2·year-1). The local climate warming in the Baltic region caused ongoing eutrophication and harmful algae blooms in the Curonian Lagoon despite of significant reduction of nutrients loading in 1990s-2000s. Harmful algal blooms in July-October (chlorophyll to 700-3400 μg/l) result in deterioration of the water chemical parameters, death of fish in the coastal zone and pollution

  6. Impacts of maintenance channel dredging in a northern Adriatic coastal lagoon. I: Effects on sediment properties, contamination and toxicity

    NASA Astrophysics Data System (ADS)

    Guerra, Roberta; Pasteris, Andrea; Ponti, Massimo

    2009-10-01

    Conservation and management of coastal lagoons envisage direct human intervention. To prevent siltation and to preserve the hydrodynamics features of the lagoon system, the inner channels undergo regular maintenance dredging. Sediment properties (RDP, organic matter, grain size), trace metals (Cd, Cu, Cr, Hg, Ni, and Pb), and toxicity vs. the amphipod Corophium insidiosum and the luminescent bacterium Vibrio fischeri, were analysed before and after dredging operations in a coastal lagoon (Pialassa Baiona, Italy). To detect the actual impacts, disturbed sites were contrasted with multiple controls in two distinct times, i.e. before and after disturbance, according to a sampling design based on Beyond BACI principles. The integrated methodology here adopted suggests that dredging operations carried out are not likely to pose dramatic effects on environmental quality of the lagoon.

  7. Accuracy of inverse dispersion method with open-path remote sensing instrument for measuring gas emission from waste lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trace gas emission from treatment lagoons and storage ponds pose challenging conditions for existing micrometeorological techniques due to surface inhomogeneity and short fetch to establish equilibrated microclimate conditions within the water boundary. This study evaluated the accuracy of an emergi...

  8. ANALYSIS OF LAGOON SAMPLES FROM DIFFERENT CONCENTRATED ANIMAL FEEDING OPERATIONS (CAFOS) FOR ESTROGENS AND ESTROGEN CONJUGATES (PRESENTATION)

    EPA Science Inventory

    Although Concentrated Animal Feeding Operations (CAFOs) have been identified as potentially important sources for the release of estrogens into the environment, information is lacking on the concentrations of estrogens in whole lagoon effluents (including suspended solids) which ...

  9. Characterization and evolution of the sediments of a Mediterranean coastal lagoon located next to a former mining area.

    PubMed

    García, Gregorio; Muñoz-Vera, Ana

    2015-11-15

    Coastal lagoons are ecosystems that are relatively enclosed water bodies under the influence of both the terrestrial and the marine environment, being vulnerable to human impacts. Human activities, such as mining extraction, are significant anthropogenic coastal stressors that can negatively affect ecosystems and communities. In light of the above, the objective of this research is to examine the influence of metal mining activities on the composition of sediments of a Mediterranean coastal lagoon, named Mar Menor. This paper presents a comprehensive characterization for grain size, mineralogy, geochemistry and organic matter of sediments of this coastal lagoon, investigating their variation along space and time. Sedimentation dynamics are ruling clearly the grain size predominant in each area of the Mar Menor coastal lagoon, determining the existence of entrainment, transport and sedimentation areas. For minerals, elements and organic matter, sedimentation dynamics are also determining their distribution.

  10. Benthic foraminifera distribution in a tourist lagoon in Rio de Janeiro, Brazil: a response to anthropogenic impacts.

    PubMed

    Vilela, Claudia Gutterres; Batista, Daniele Silva; Baptista Neto, José Antonio; Ghiselli, Renato Olindo

    2011-10-01

    Rodrigo de Freitas Lagoon, located in the Rio de Janeiro City, receives several types of polluted discharges. The knowledge of the sediment microfauna correlated with heavy metal and organic matter concentrations could supply important data about the conditions of the lagoon. The benthic foraminiferal assemblage presented larger diversity and more abundant samples in the lagoon entrance than in the inner area. The Ammonia tepida - Elphidium excavatum foraminiferal assemblage is characterized by dwarf, corroded and weak organisms. Agglutinated species were found only near the entrance. Low abundance values and sterility of five samples in the inner area (north/northeast) can be caused by high levels of heavy metals and organic matter. A. tepida shows negative correlation with increasing heavy metals values. PAHs and coprostanol high indexes, and the absence or low presence of microfauna in samples around the lagoon margin confirm illegal flows from gas stations and domestic sewage.

  11. Identifying nutrient sources to three lagoons at Ofu and Olosega, American Samoa using δ15N of benthic macroalgae

    USGS Publications Warehouse

    Garrison, Virginia H.; Kroeger, Kevin D.; Fenner, Douglas; Craig, Peter

    2007-01-01

    Degradation of nearshore habitats is a serious problem in some areas of American Samoa, such as in Pago Pago Harbor on Tutuila Island, and is a smaller but chronic problem in other areas. Sedimentation, pollution, nutrient enrichment from surface runoff or groundwater, and trampling are the major factors causing the changes (Peshut and Brooks, 2005). On the outer islands of Ofu and Olosega (Manu’a Islands; Fig. 1), there is an interesting contrast between relatively pristine lagoon habitats not far from comparatively degraded lagoon habitats. To’aga lagoon on the southeast side of Ofu Island (Fig. 1) has clear waters, a high diversity of corals and fishes, no human habitations, and an undeveloped watershed with no streams. To’aga lagoon is within the boundaries of the National Park of American Samoa and is the site of long-term research on coral reef resilience and global climate change. Only 3 km to the east of To’aga is a degraded lagoon that fronts Olosega Village. The Olosega lagoon is similar in size but has significantly less live coral than To’aga, and blooms of filamentous algae have been reported to cover the Olosega lagoon/reef flat bottom (unpublished data, PC; Fig. 2). The islands are influenced by the same regional-scale and biogeochemical regimes, and both islands are remnants of a volcanic caldera (Craig, 2005). Thus, local factors operating on the scale of a kilometer or less are thought to be driving the differences observed between lagoons. Land disturbance is limited to a road linking the villages, the clearing of vegetation for buildings, and two village dump sites located on the narrow strip of land between the steep slopes of the islands and the shoreline; there is no industry or associated pollution on either island. Cesspools are used for sewage disposal. Nutrient enrichment (from cesspools) of groundwater and the lagoon, as well as trampling during gleaning of reef organisms, are possible factors affecting the spatial relief

  12. Spatial variations in dietary organic matter sources modulate the size and condition of fish juveniles in temperate lagoon nursery sites

    NASA Astrophysics Data System (ADS)

    Escalas, Arthur; Ferraton, Franck; Paillon, Christelle; Vidy, Guy; Carcaillet, Frédérique; Salen-Picard, Chantal; Le Loc'h, François; Richard, Pierre; Darnaude, Audrey Michèle

    2015-01-01

    Effective conservation of marine fish stocks involves understanding the impact, on population dynamics, of intra-specific variation in nursery habitats use at the juvenile stage. In some regions, an important part of the catching effort is concentrated on a small number of marine species that colonize coastal lagoons during their first year of life. To determine the intra-specific variation in lagoon use by these fish and their potential demographic consequences, we studied diet spatiotemporal variations in the group 0 juveniles of a highly exploited sparid, the gilthead seabream (Sparus aurata L.), during their ∼6 months stay in a NW Mediterranean lagoon (N = 331, SL = 25-198 mm) and traced the origin of the organic matter in their food webs, at two lagoon sites with contrasted continental inputs. This showed that the origin (marine, lagoonal or continental) of the organic matter (OM) available in the water column and the sediment can vary substantially within the same lagoon, in line with local variations in the intensity of marine and continental inputs. The high trophic plasticity of S. aurata allows its juveniles to adapt to resulting differences in prey abundances at each site during their lagoon residency, thereby sustaining high growth irrespective of the area inhabited within the lagoon. However, continental POM incorporation by the juveniles through their diet (of 21-37% on average depending on the site) is proportional to its availability in the environment and could be responsible for the greater fish sizes (of 28 mm SL on average) and body weights (of 40.8 g on average) observed at the site under continental influence in the autumn, when the juveniles are ready to leave the lagoon. This suggests that continental inputs in particulate OM, when present, could significantly enhance fish growth within coastal lagoons, with important consequences on the local population dynamics of the fish species that use them as nurseries. As our results indicate that

  13. A new model evaluating Holocene sediment dynamics: Insights from a mixed carbonate-siliciclastic lagoon (Bora Bora, Society Islands, French Polynesia, South Pacific)

    NASA Astrophysics Data System (ADS)

    Isaack, Anja; Gischler, Eberhard; Hudson, J. Harold; Anselmetti, Flavio S.; Lohner, Andreas; Vogel, Hendrik; Garbode, Eva; Camoin, Gilbert F.

    2016-08-01

    Mixed carbonate-siliciclastic lagoons of barrier reefs provide great potential as sedimentary archives focusing on paleoenvironmental and paleoclimatic changes as well as on event deposition. Sediment sources include lagoonal carbonate production, the marginal reef and the volcanic hinterland. Mixed carbonate-siliciclastic continent-attached coastal lagoons have been intensively studied, however, their isolated oceanic counterparts have been widely disregarded. Here, we present a new model of Holocene sediment dynamics in the barrier-reef lagoon of Bora Bora based on sedimentological, paleontological, geochronological and geochemical data. The lagoonal succession started with a Pleistocene soil representing the Lowstand Systems Tract. As the rising Holocene sea inundated the carbonate platform, peat accumulated locally 10,650-9400 years BP. Mixed carbonate-siliciclastic sedimentation started ca. 8700-5500 years BP and represents the Transgressive Systems Tract. During that time, sediments were characterized by relatively coarse grain size and contained high amounts of terrestrial material from the volcanic hinterland as well as carbonate sediments mainly produced within the lagoon. Siliciclastic content decreases throughout the Holocene. After the rising sea had reached its modern level, sand aprons formed between reef crest and lagoon creating transport pathways for reef-derived material leading to carbonate-dominated sedimentation ca. 6000-3000 years BP during the Highstand Systems Tract. However, mainly fine material was transported and accumulated in the lagoon while coarser grains were retained on the prograding sand apron. From ca. 4500-500 years BP, significant variations in grain-size, total organic carbon as indicator for primary productivity, Ca and Cl element intensities as qualitative indicators for carbonate availability and lagoonal salinity are seen. Such patterns could indicate event (re-)deposition and correlate with contemporaneous event deposits

  14. Chemotaxis of Escherichia coli to Norepinephrine (NE) Requires Conversion of NE to 3,4-Dihydroxymandelic Acid

    PubMed Central

    Pasupuleti, Sasikiran; Sule, Nitesh; Cohn, William B.; MacKenzie, Duncan S.

    2014-01-01

    Norepinephrine (NE), the primary neurotransmitter of the sympathetic nervous system, has been reported to be a chemoattractant for enterohemorrhagic Escherichia coli (EHEC). Here we show that nonpathogenic E. coli K-12 grown in the presence of 2 μM NE is also attracted to NE. Growth with NE induces transcription of genes encoding the tyramine oxidase, TynA, and the aromatic aldehyde dehydrogenase, FeaB, whose respective activities can, in principle, convert NE to 3,4-dihydroxymandelic acid (DHMA). Our results indicate that the apparent attractant response to NE is in fact chemotaxis to DHMA, which was found to be a strong attractant for E. coli. Only strains of E. coli K-12 that produce TynA and FeaB exhibited an attractant response to NE. We demonstrate that DHMA is sensed by the serine chemoreceptor Tsr and that the chemotaxis response requires an intact serine-binding site. The threshold concentration for detection is ≤5 nM DHMA, and the response is inhibited at DHMA concentrations above 50 μM. Cells producing a heterodimeric Tsr receptor containing only one functional serine-binding site still respond like the wild type to low concentrations of DHMA, but their response persists at higher concentrations. We propose that chemotaxis to DHMA generated from NE by bacteria that have already colonized the intestinal epithelium may recruit E. coli and other enteric bacteria that possess a Tsr-like receptor to preferred sites of infection. PMID:25182492

  15. Electron transfer mediated decay in NeXe triggered by K-LL Auger decay of Ne

    NASA Astrophysics Data System (ADS)

    Stumpf, Vasili; Scheit, Simona; Kolorenč, Přemysl; Gokhberg, Kirill

    2017-01-01

    In this article we present the results of an ab initio study of electron transfer mediated decay (ETMD) in NeXe dimer triggered by the K-LL Auger decay of Ne. We found that the Ne2+ (2p-21D)Xe and Ne2+ (2p-21S)Xe states which are strongly populated in the Auger process may decay by ETMD emitting a slow electron and leading to the Coulomb explosion of the dimer which results in Ne+ and Xe2+ ions. We also computed the corresponding decay widths, the ETMD electron spectra, and the kinetic energy release of the nuclei (KER) spectra. We showed that the spectra corresponding to the decaying states which derive from the two multiplets have completely different shape which reflects differing accessibility of the ETMD final states. Thus, in the Ne2+ (2p-21S)Xe state ETMD is allowed for all interatomic distances accessible in nuclear dynamics, while in the Ne2+ (2p-21D)Xe state the ETMD channels become closed one by one. This in turn leads to the different behavior of the ETMD decay widths and ultimately the spectra. We show how these differences make it possible to study ETMD of the two states separately in a coincident measurement. We also discuss how the dynamics which follow ETMD in the final state manifold may lead to the appearance of the unusual products: Ne, Xe3+ and a slow electron.

  16. Diazotroph community succession during the VAHINE mesocosm experiment (New Caledonia lagoon)

    NASA Astrophysics Data System (ADS)

    Turk-Kubo, K. A.; Frank, I. E.; Hogan, M. E.; Desnues, A.; Bonnet, S.; Zehr, J. P.

    2015-12-01

    The VAHINE mesocosm experiment, conducted in the low-nutrient low-chlorophyll waters of the Noumea lagoon (coastal New Caledonia) was designed to trace the incorporation of nitrogen (N) fixed by diazotrophs into the food web, using large volume (50 m3) mesocosms. This experiment provided a unique opportunity to study the succession of different N2-fixing microorganisms (diazotrophs) and calculate in situ net growth and mortality rates in response to fertilization with dissolved inorganic phosphate (DIP) over a 23-day period, using quantitative polymerase chain reaction (qPCR) assays targeting widely distributed marine diazotroph lineages. Inside the mesocosms, the most abundant diazotroph was the heterocyst-forming Richelia associated with Rhizosolenia (Het-1) in the first half of the experiment, while unicellular cyanobacterial Group C (UCYN-C) became abundant during the second half of the experiment. Decreasing DIP concentrations following the fertilization event and increasing temperatures were significantly correlated with increasing abundances of UCYN-C. Maximum net growth rates for UCYN-C were calculated to range between 1.23 ± 0.07 and 2.16 ± 0.07 d-1 in the mesocosms, which are among the highest growth rates reported for diazotrophs. Outside the mesocosms in the New Caledonia lagoon, UCYN-C abundances remained low, despite increasing temperatures, suggesting that the microbial community response to the DIP fertilization created conditions favorable for UCYN-C growth inside the mesocosms. Diazotroph community composition analysis using PCR targeting a component of the nitrogenase gene (nifH) verified that diazotrophs targeted in qPCR assays were collectively among the major lineages in the lagoon and mesocosm samples, with the exception of Crocosphaera-like phylotypes, where sequence types not typically seen in the oligotrophic ocean grew in the mesocosms. Maximum net growth and mortality rates for nine diazotroph phylotypes throughout the 23-day

  17. Environmental occurrence and biota concentration of phthalate esters in Epe and Lagos Lagoons, Nigeria.

    PubMed

    Adeogun, Aina O; Ibor, Oju R; Omogbemi, Emmanuel D; Chukwuka, Azubuike V; Adegbola, Rachel A; Adewuyi, Gregory A; Arukwe, Augustine

    2015-07-01

    The high global occurrence of phthalates in different environmental matrixes has resulted in the detection of their metabolites in human urine, blood, and breast milk, indicating a widespread human exposure. In addition, the notorious endocrine disrupting effects of phthalates have shown that they mimic or antagonize the action of endogenous hormones, consequently producing adverse effects on reproduction, growth and development. Herein, we have studied the occurrence of phthalate esters (PEs) in water, sediment and biota of two lagoons (Epe and Lagos) in Nigeria. Two fish species (Tilapia guineensis, and Chrysichthys nigrodigitatus) and a crustacean (the African river prawn--Macrobrachium vollenhovenii) were analyzed for PEs levels using a HPLC method and the derived values were used for calculating bioconcentration factor (BCF), biota-sediment accumulation factor (BSAF) and phthalate pollution index (PPI) in the biota and environment. We observed that the growth and health condition of the fish species were normal with a k-factor of >1. Sediment PE levels were compared with water, at both lagoons showing concentration pattern that is characterized as DEHP = DEP > DBP. We observed that DBP was the predominant compound in T. guineensis, C. nigrodigitatus and African prawn, at both lagoons, showing organ-specific differences in bioconcentration (BCF and BSAF) patterns in the fish species. While there were no observed consistency in the pattern of PE concentration in fish organs, elevated DBP levels in different fish organs may be related to fish habitat and degradation level of phthalates. Low concentration of DEHP, compared with DBP and DEP, was measured in fish organs and whole prawn body. The BSAF values for DEHP were lowest, and highest for DBP for all species at both lagoons, and DEHP easily accumulated more in the sediment (sediment PPI = 0.28 and 0.16 for Epe and Lagos lagoon, respectively). Overall, our findings suggest a broader environmental and human

  18. Water exchanges between a multi-inlet lagoon and the ocean: the role of forcing mechanisms

    NASA Astrophysics Data System (ADS)

    Fabião, João Pedro Farinha; Rodrigues, Marta Filipa Gomes; Fortunato, André Bustorff; Jacob, José Manuel Quintela de Brito; Cravo, Alexandra Maria Francisco

    2016-02-01

    Understanding the influence of the main drivers controlling the circulation and the transport in coastal lagoons is a necessary step towards the description of the dynamics of their ecosystems. Thus, the influence of the main physical drivers on the water exchanges in a multi-inlet barrier island (western sector of the Ria Formosa coastal lagoon, Portugal) was investigated. Several scenarios of tide, wind, bathymetry and point source discharges were simulated using a three-dimensional circulation model and a particle-tracking model. The circulation is adequately reproduced by the hydrodynamic model, with root mean square errors of about 5-8 cm for the water levels and 5-10 cm/s for the cross-sectional averaged velocities in the western inlets and main channels. Wind has a negligible effect on the modelled water levels and cross-sectional velocities, with differences smaller than 1 % between the simulations with and without wind. However, results show that wind influences significantly the transport by affecting the residual circulation, with distinct effects depending on the wind direction. Upwelling favourable winds (with west component) increase the landward transport through the Faro-Olhão inlet and promote a larger dispersion of the water-borne material inside the lagoon. The residual circulation between the three inlets of the western sector of the lagoon is also significantly affected by the bathymetry. Results show a decrease of about 50 % of the tidal prism of the Ancão inlet between 2002 and 2011, which reduces its capacity to export waterborne material to the adjacent coastal area and increases the residence times in some areas of the lagoon, with potentially adverse effects on the ecosystems' health. The dispersion of potential contaminants from point sources inside the lagoon to the coastal area depends on the combined effect of the tidal phase and amplitude and the location of the source. Mean residence times for the discharges from the wastewater

  19. Combining geochemical proxies in Porites coral cores from Chuuk Lagoon, Micronesia

    NASA Astrophysics Data System (ADS)

    Wagner, A. J.; Zivkovic, J.; Anderson, D.; Umling, N. E.

    2013-12-01

    Chuuk Lagoon (7°N, 152°E), part of the Federated States of Micronesia, is centrally located in the Western Pacific Warm Pool (WPWP) and provides an ideal location for studies of El Niño - Southern Oscillation (ENSO) and Warm Pool processes. The WPWP is a key aspect of the global climate, exchanging heat and carbon with the atmosphere as well as with the surrounding ocean and the underlying water masses. Recent work has indicated long-term changes in the WPWP, including freshening and warming, that have been attributed to climate change. This region also experiences large fluctuations in precipitation and temperature due to interannual oscillations in ENSO. Oxygen isotope (δ18O) data from corals provides insight into the isotopic ratio of the water in which the corals grew their aragonitic skeletons. However, the oxygen isotope ratio of seawater varies with both changes in temperature and salinity. Sr/Ca ratios vary with seawater temperature and, when combined with δ18O, can be used to interpret both temperature and salinity variations. Three coral cores from large Porites lobata coral heads were collected from Chuuk Lagoon in June 2011, and one additional core was collected in 2008. Two cores (one in 2008 and another in 2011) were collected near the main island within the lagoon where they are subject to large precipitation and temperature variability due to fluctuations in ENSO. The remaining two cores were collected at the outer edge of the atoll, just inside of the barrier reef. These cores were collected in less than 3 m of water and were constantly being flushed with water from the open ocean warm pool. Seasonal variability in temperature and salinity are expected to be very low at this site. Stable isotope (δ18O, δ13C) and trace element (Sr/Ca) analyses for the upper portion of these cores will be presented and compared to ENSO variability and observed trends in the WPWP. An adjacent lagoon coral is valuable in developing the lagoon history, while the

  20. Potential changes in bacterial metabolism associated with increased water temperature and nutrient inputs in tropical humic lagoons.

    PubMed

    Scofield, Vinicius; Jacques, Saulo M S; Guimarães, Jean R D; Farjalla, Vinicius F

    2015-01-01

    Temperature and nutrient concentrations regulate aquatic bacterial metabolism. However, few studies have focused on the effect of the interaction between these factors on bacterial processes, and none have been performed in tropical aquatic ecosystems. We analyzed the main and interactive effects of changes in water temperature and N and P concentrations on bacterioplankton production (BP), bacterioplankton respiration (BR) and bacterial growth efficiency (BGE) in tropical coastal lagoons. We used a factorial design with three levels of water temperature (25, 30, and 35°C) and four levels of N and/or P additions (Control, N, P, and NP additions) in five tropical humic lagoons. When data for all lagoons were pooled together, a weak interaction was observed between the increase in water temperature and the addition of nutrients. Water temperature alone had the greatest impact on bacterial metabolism by increasing BR, decreasing BP, and decreasing BGE. An increase of 1°C lead to an increase of ~4% in BR, a decrease of ~0.9% in BP, and a decrease of ~4% in BGE. When data were analyzed separately, lagoons responded differently to nutrient additions depending on Dissolved Organic Carbon (DOC) concentration. Lagoons with lowest DOC concentrations showed the strongest responses to nutrient additions: BP increased in response to N, P, and their interaction, BR increased in response to N and the interaction between N and P, and BGE was negatively affected, mainly by the interaction between N and P additions. Lagoons with the highest DOC concentrations showed almost no significant relationship with nutrient additions. Taken together, these results show that different environmental drivers impact bacterial processes at different scales. Changes of bacterial metabolism related to the increase of water temperature are consistent between lagoons, therefore their consequences can be predicted at a regional scale, while the effect of nutrient inputs is specific to different

  1. Lagoonal reef accretion and holocene sea-level history from three atolls in the Cook Islands, Central South Pacific

    USGS Publications Warehouse

    Gray, S.C.; Hein, J.R.

    2005-01-01

    Radiocarbon ages of corals from cores collected at nine drill sites in the lagoons of three atolls (Pukapuka, Rakahanga, Aitutaki, Cook Islands) provide a history of lagoon sedimentation in response to Holocene sea-level rise and stabilization. Holocene lagoonal reefs were established between 8700 and 7800 years B.P. on 130,000-200,000 year-old reef platforms that are presently 7 to 22 m below the floor of the lagoons. Comparison of radiocarbon ages of the deepest corals to published sea-level curves indicate that Holocene reefs colonized these substrates rapidly (lagoon flooding, in water depths of less than 8 m. Subsequently, reef growth lagged behind sea-level rise until the outer reef rims reached sea level between 5000 and 4000 years B.P. Average vertical sediment accretion rates for the Holocene in the lagoons varied by location (83 ?? 2 to 278 ?? 8 cm/ka) and decreased through the Holocene in six of seven drill holes as the lagoons shallowed and became enclosed by the outer reef. A sample from an emergent (<0.5 m above present mean tide) reef on Rakahanga is 4610 ?? 100 years old, which may indicate a higher middle Holocene relative sea level on Rakahanga. Coral growth in Rakahanga lagoon ceased less than 2000 years ago, but was prolific in the early to middle Holocene. The timing and pattern of Holocene reef development exhibited in the Cook Islands is consistent with other oceanic islands. An assessment of the response of reef development to sea-level change during the Holocene provides a baseline to predict how future sea-level changes may affect the morphology of modern reefs.

  2. Potential changes in bacterial metabolism associated with increased water temperature and nutrient inputs in tropical humic lagoons

    PubMed Central

    Scofield, Vinicius; Jacques, Saulo M. S.; Guimarães, Jean R. D.; Farjalla, Vinicius F.

    2015-01-01

    Temperature and nutrient concentrations regulate aquatic bacterial metabolism. However, few studies have focused on the effect of the interaction between these factors on bacterial processes, and none have been performed in tropical aquatic ecosystems. We analyzed the main and interactive effects of changes in water temperature and N and P concentrations on bacterioplankton production (BP), bacterioplankton respiration (BR) and bacterial growth efficiency (BGE) in tropical coastal lagoons. We used a factorial design with three levels of water temperature (25, 30, and 35°C) and four levels of N and/or P additions (Control, N, P, and NP additions) in five tropical humic lagoons. When data for all lagoons were pooled together, a weak interaction was observed between the increase in water temperature and the addition of nutrients. Water temperature alone had the greatest impact on bacterial metabolism by increasing BR, decreasing BP, and decreasing BGE. An increase of 1°C lead to an increase of ~4% in BR, a decrease of ~0.9% in BP, and a decrease of ~4% in BGE. When data were analyzed separately, lagoons responded differently to nutrient additions depending on Dissolved Organic Carbon (DOC) concentration. Lagoons with lowest DOC concentrations showed the strongest responses to nutrient additions: BP increased in response to N, P, and their interaction, BR increased in response to N and the interaction between N and P, and BGE was negatively affected, mainly by the interaction between N and P additions. Lagoons with the highest DOC concentrations showed almost no significant relationship with nutrient additions. Taken together, these results show that different environmental drivers impact bacterial processes at different scales. Changes of bacterial metabolism related to the increase of water temperature are consistent between lagoons, therefore their consequences can be predicted at a regional scale, while the effect of nutrient inputs is specific to different

  3. The impact of human activities on the flushing properties of a semi-enclosed lagoon: Xiaohai, Hainan, China.

    PubMed

    Gong, Wenping; Shen, Jian; Jia, Jianjun

    2008-02-01

    In this study, a Lagrangian particle tracking model driven by hydrodynamic fields was used to investigate the changes of flushing properties in Xiaohai Lagoon resulting from natural evolution and influences of human activities. Comparisons of residence times between 1936 and 2001 indicate that the flushing efficiency of the lagoon has deteriorated greatly during the past seven decades. Over this period, the average residence time of the lagoon has increased from 45 to 71 days, an increase of 59%. The Lagrangian residual velocity has decreased from 1936 to 2001 in the large portions of the lagoon, and the spatial distribution pattern of the residual current has changed significantly. The well-developed horizontal circulations in 1936 disappeared. Instead, the horizontal Lagrangian residual velocity showed uniformly seaward motion with reduced velocity in 2001. Human activities have incurred great impacts on the deterioration of flushing efficiency. The reduction of river inflow imposed the most significant impact, causing an increase of average residence time by 33%. The land reclamation in the lagoon came as the second most significant factor, causing an increase of 15%. Closure of the North Opening had posed minor impact. The model results suggest that restoring the river inflow, as well as the dredging of the tidal channel and the inner lagoon, should be the top proprieties for future water quality management.

  4. Improved dissolved oxygen status following removal of exotic weed mats in important fish habitat lagoons of the tropical Burdekin River floodplain, Australia.

    PubMed

    Perna, Colton; Burrows, Damien

    2005-01-01

    The Burdekin delta floodplain, north Queensland, is highly modified for agricultural purposes. Riparian condition is very poor and exotic aquatic weeds dominate waterways. Historically, most streams and lagoons were highly seasonal, but those now used for the delivery of irrigation water maintain elevated flows and increased turbidity and nutrient loading. These factors have aided exotic weed growth and many major lagoons are covered by dense water hyacinth (Eichhornia crassipes) mats which greatly reduce dissolved oxygen levels, one of the most important water quality variables for aquatic fauna. Mechanical harvesting of water hyacinth from several of these lagoons resulted in rapid and substantial increases in dissolved oxygen saturation, and improved suitability of the habitat to support fish species. Decrease in dissolved oxygen as water passes sequentially through weed-infested lagoons, justified the approach of harvesting upstream lagoons first, however, the channels that connect these lagoons remain weed-infested and are still impacting upon downstream oxygen levels.

  5. Scattering study of the Ne + NeH{sup +}(v{sub 0} = 0, j{sub 0} = 0) → NeH{sup +} + Ne reaction on an ab initio based analytical potential energy surface

    SciTech Connect

    Koner, Debasish; Panda, Aditya N.; Barrios, Lizandra; González-Lezana, Tomás

    2016-01-21

    Initial state selected dynamics of the Ne + NeH{sup +}(v{sub 0} = 0, j{sub 0} = 0) → NeH{sup +} + Ne reaction is investigated by quantum and statistical quantum mechanical (SQM) methods on the ground electronic state. The three-body ab initio energies on a set of suitably chosen grid points have been computed at CCSD(T)/aug-cc-PVQZ level and analytically fitted. The fitting of the diatomic potentials, computed at the same level of theory, is performed by spline interpolation. A collinear [NeHNe]{sup +} structure lying 0.72 eV below the Ne + NeH{sup +} asymptote is found to be the most stable geometry for this system. Energies of low lying vibrational states have been computed for this stable complex. Reaction probabilities obtained from quantum calculations exhibit dense oscillatory structures, particularly in the low energy region and these get partially washed out in the integral cross section results. SQM predictions are devoid of oscillatory structures and remain close to 0.5 after the rise at the threshold thus giving a crude average description of the quantum probabilities. Statistical cross sections and rate constants are nevertheless in sufficiently good agreement with the quantum results to suggest an important role of a complex-forming dynamics for the title reaction.

  6. Deep Learning MicroBooNE

    NASA Astrophysics Data System (ADS)

    Genty, Victor; Terao, Kazuhiro; Wonjirad, Taritree

    2017-01-01

    The Liquid Argon Time Projection Chamber (LAr TPC) technology provides a high resolution image of ionizing particle trajectories raising a need for new event reconstruction techniques based on pattern recognition. The traditional bottoms-up reconstruction approach to extract physics involves a complex sequence of signal waveform processing, 2D and/or 3D geometrical pattern recognition, calorimetry, and finally particle identification before a neutrino interaction can be identified in an event. We present a top-down reconstruction approach using a machine learning algorithm called Deep Learning which uses convolutional neural networks to find a neutrino interaction in a LAr TPC image. We trained our network on images of simulated single particles and neutrinos overlaid on cosmic-ray background data taken from the MicroBooNE detector. In this talk, we present our result that shows convolutional networks can successfully learn LAr TPC images to perform particle identification, neutrino event selection, and localization of a neutrino interaction vertex in a large LAr TPC image.

  7. Sex-specific daily spawning seaward migration of striped mullet Mugil cephalus in a coastal lagoon.

    PubMed

    Katselis, G; Koukou, K; Ramfos, A; Moutopoulos, D K

    2015-08-01

    The sex-specific daily spawning seaward migration of striped mullet Mugil cephalus was analysed in Palaiopotamos Lagoon (western Greek coast, eastern Mediterranean Sea) in an 86 day time series. The data set included the daily number of M. cephalus catches in barrier traps, as well as a time series of some weather variables. The analysis revealed an important linkage of the daily migration rate as well as a sex-specific response of the species to the lunar cycle and the short-term fluctuation of weather variables. The daily migration pattern of females was more persistent than that of males, indicating a possible female leadership role during the spawning migration. Multiregression models described quite accurately the sex-specific daily migration rates of the species, thus providing a potentially powerful tool regarding the lagoon fishery management of M. cephalus, especially in the context of climate change.

  8. Hematological parameters of Hoplias malabaricus (Characiformes: Erythrinidae) parasitized by Monogenea in lagoons in Pirassununga, Brazil.

    PubMed

    Corrêa, Lincoln Lima; Karling, Letícia Cucolo; Takemoto, Ricardo Massato; Ceccarelli, Paulo Sérgio; Ueta, Marlene Tiduko

    2013-01-01

    Hematology is an important pathological and diagnostic tool. This paper describes the hematological parameters of 76 specimens of Hoplias malabaricus infested with monogenean parasites, which were collected from two lagoons. The hematological parameters included: erythrocyte count (Er), microhematocrit (Hct), hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). The blood parameters showed no significant changes associated with the infestation. Water temperature was found to be negatively correlated with MCV and Hct, with values of rs= -0.52, p<0.0001 and rs= -0.48, p<0.0001, respectively. The mean Relative Condition Factor was Kn=1.01, indicating good health conditions of the fish in these lagoons. No correlation was found between the monogenean infestation and the blood parameters, or between the environmental factors and the monogeneans.

  9. Determining the footprint of sewage discharges in a coastal lagoon in South-Western Europe.

    PubMed

    Cravo, Alexandra; Fernandes, Denise; Damião, Tânia; Pereira, Catarina; Reis, Margarida P

    2015-07-15

    Ria Formosa is a highly productive lagoon in South-Western Europe, supporting 90% of Portuguese clam production. Decreases in shellfish production have been ascribed to deterioration of water quality due to sewage discharges. Nevertheless, a thorough study considering their impact on the whole lagoon system has been missing. This work determined the sewage footprint from the major sewage treatment plants (STP) regarding eutrophication and microbial contamination within a two-year monitoring program. This focused on salinity, oxygen, nutrients, chlorophyll-a and faecal coliforms. Areas closer to sewage discharges showed an evident impact with maximum effects detected at the major STP. However, globally, the Ria Formosa did not show clear eutrophication problems due to high tidal flushing. Ammonium, oxygen, chlorophyll-a and faecal coliforms, unlike the other parameters, showed no seasonality. Microbiological contamination was of great concern and public health issues could be avoided by settling shellfish beds at least 500 m away from discharge points.

  10. Resource Partitioning Among Planktivorous Fish Larvae and Fry in a Mediterranean Coastal Lagoon

    NASA Astrophysics Data System (ADS)

    Gisbert, E.; Cardona, L.; Castelló, F.

    1996-12-01

    Resource partioning among the planktivorous stages of eight fish species occurring in a Mediterranean coastal lagoon was studied. Five species were migratory mullets that spawned in the sea ( Liza ramada, L. aurata, L. saliens, Chelon labrosusand Mugil cephalus), while the other three species were resident and spawned in the lagoon ( Atherina boyeri, Cyprinus carpioand Gambusia holbrooki). Mullet fry exhibited similar diets, based on the consumption of zooplanktonic Crustacea such as copepods and cladocerans, although adult chironomids were also important. Gambusia holbrookiand A. boyerifed on small prey such as copepod nauplii, copepodites and rotifers, while C. carpioconsumed larger prey preferentially (cladocerans and copepods). According to the trophic overlap and niche width results, seven species pairs could be competing in the estuary, although further experimental evidence is still required.

  11. [Structure and bioassessment of benthic communities of a lagoonal ecosystem of the Atlantic Moroccan coast].

    PubMed

    Bazairi, Hocein; Bayed, Abdellatif; Hily, Christian

    2005-01-01

    The Merja Zerga lagoon is a semi-enclosed marine ecosystem in which various types of human activities have been developed. This paper characterizes the biosedimentary units of the lagoon and defines a reference status of the quality and health of the macrozoobenthic communities that can be used as bioindicators of the quality of the global marine environment. Specific and functional diversity were high: 147 taxa were identified; they were distributed within seven main trophic groups. Trophic structure is dominated by the suspension-feeding bivalve Cerastoderma edule and the deposit-feeding bivalve Scrobicularia plana, while micrograzers and macroherbivores remain low. Biotic index values indicated that the site is moderately perturbed and that the benthic communities are unbalanced. Nevertheless, the communities showed a seasonal stability of abundances and a high specific richness all through the year.

  12. Transcriptomic resources for environmental risk assessment: a case study in the Venice lagoon.

    PubMed

    Milan, M; Pauletto, M; Boffo, L; Carrer, C; Sorrentino, F; Ferrari, G; Pavan, L; Patarnello, T; Bargelloni, L

    2015-02-01

    The development of new resources to evaluate the environmental status is becoming increasingly important representing a key challenge for ocean and coastal management. Recently, the employment of transcriptomics in aquatic toxicology has led to increasing initiatives proposing to integrate eco-toxicogenomics in the evaluation of marine ecosystem health. However, several technical issues need to be addressed before introducing genomics as a reliable tool in regulatory ecotoxicology. The Venice lagoon constitutes an excellent case, in which the assessment of environmental risks derived from the nearby industrial activities represents a crucial task. In this context, the potential role of genomics to assist environmental monitoring was investigated through the definition of reliable gene expression markers associated to chemical contamination in Manila clams, and their subsequent employment for the classification of Venice lagoon areas. Overall, the present study addresses key issues to evaluate the future outlooks of genomics in the environmental monitoring and risk assessment.

  13. Aerated swine lagoon wastewater: a promising alternative medium for Botryococcus braunii cultivation in open system.

    PubMed

    Liu, Junzhi; Ge, Yaming; Cheng, Haixiang; Wu, Lianghuan; Tian, Guangming

    2013-07-01

    To understand the potential of using swine lagoon wastewater to cultivate Botryococcus braunii for biofuel production, growth characteristics of B. braunii 765 cultivated in aerated swine lagoon wastewater (ASLW) without sterilization and pH adjustment were investigated. The results showed that the alga strain could maintain competitive advantage over the 26-day cultivation. The highest dry biomass of alga grown in ASLW was 0.94 mg L(-1) at day 24, which was 1.73 times that grown in BG11 medium, an artificial medium normally used for B. braunii cultivation. And the algal hydrocarbon content was 23.8%, being more than twice that in BG11 medium. Additionally, after the 26-day cultivation, about 40.8% of TN and 93.3% of TP in ASLW were removed, indicating also good environmental benefits of algal bioremediation.

  14. Organotins (TBT and DBT) in water, sediments, and gastropods of the southern Venice lagoon (Italy).

    PubMed

    Berto, D; Giani, M; Boscolo, R; Covelli, S; Giovanardi, O; Massironi, M; Grassia, L

    2007-01-01

    The release of tributyltin (TBT) from maritime traffic represents one of the main problems of direct, diffuse, and continued contamination of the marine environment. In the present survey, the concentrations of TBT and dibultytin (DBT) in brackish waters, sediments, and the gastropods Nassarius nitidus were evaluated in order to estimate the contamination of the southern part of the Venice lagoon. TBT and DBT were determined by GC-MS/MS. Recent contamination of TBT was found in brackish waters near marinas, whereas the highest concentrations of TBT and DBT were observed in surface sediments at dockyards and harbours. High content of organotin in the gastropods sampled near the dockyards, harbours, and marinas showed a mobilisation from the sediments through the food web. The present study allowed assessment of whether, despite the ban on the use of TBT paints, waters, sediments, and biota were still being contaminated by organotin compounds in the southern Venice lagoon.

  15. Concentrations of radionuclides in reef and lagoon pelagic fish from the Marshall Islands

    SciTech Connect

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Jokela, T.A.; Brunk, J.L.; Marsh, K.V.

    1981-07-01

    A radiological survey was conducted from September through November of 1978 to assess the concentrations of persistent man-made radionuclides in the terrestrial and marine environments of 11 atolls and 2 islands of the Northern Marshall Islands. The atolls and islands include Rongelap, Utirik, Taka, Bikar, Rongerik, Ailinginae, Likiep, Jemo, Ailuk, Mejet, Wotho, Ujelang and Bikini. Over 4000 terrestrial and marine samples were collected for radionuclide analysis from 76 different islands. Soils, vegetation, indigenous animals, and cistern and groundwater were collected from the islands. Reef fish, pelagic species, clams, lagoon water, and sediments were obtained from the lagoons. A report is given of all available concentration data for /sup 137/Cs, /sup 90/Sr, /sup 239+240/Pu, /sup 238/Pu, /sup 241/Am as well as naturally occurring /sup 40/K and other gamma emitting radionuclides in tissues and organs of different species of fish collected from the atolls.

  16. Do lagoon area sediments act as traps for polycyclic aromatic hydrocarbons?

    PubMed

    Marini, Mauro; Frapiccini, Emanuela

    2014-09-01

    The coastal lagoons are vulnerable systems, located between the land and the sea, enriched by both marine and continental inputs and are among the most productive aquatic ecosystems. The purpose of this work is to understand the influence of the lagoon area sediments on the behaviour of polycyclic aromatic hydrocarbons, through the adsorption coefficient determination. In fact, the sorption of polycyclic aromatic hydrocarbons is an important process because it governs the fate, transport, bioavailability and toxicity of these compounds in sediments. It has been observed that the adsorption of polycyclic aromatic hydrocarbons in a transitional system is the outcome of different factors, such as their sources and physicochemical properties, salinity and sediment composition, hydrology and environmental conditions. The results showed that transitional areas contribute to the polycyclic aromatic hydrocarbon accumulation in the sediment turning it into a trap.

  17. Trematode infections in Pirenella conica in three sites of a mangrove lagoon in Sinai.

    PubMed

    Taraschewski, H; Paperna, I

    1982-01-01

    Over a period of 11 months, eight samples of Pirenella conica were taken at each of three sites of a mangrove lagoon in Sinai. Infection with larval trematodes, especially of Heterophyidae, was highest at the site within the mangrove thicket with a breeding colony of reef herons, the supposed definitive hosts of the Heterophyidae. The lowest frequency of infection was recorded from a tide-pool on the broad sand-flats surrounding the lagoon, where there was a great variation in the abundance of snails and xiphidiocercariae were more common than heterophyid cercariae. Predation from fish or other molluscs did not appear to be an important factor at either of these two sites. In all three sites, double infections of Heterophyidae and trematodes with xiphidiocercariae as well as of Heterophyidae and Echinostomatidae occurred less frequently than theoretically expected, but there was no competitive exclusion between Echinostomatidae and xiphidiocercariae.

  18. Carbon mass-balance modeling and carbon isotope exchange processes in the Curonian Lagoon

    NASA Astrophysics Data System (ADS)

    Barisevičiūtė, Rūta; Žilius, Mindaugas; Ertürk, Ali; Petkuvienė, Jolita

    2016-04-01

    The Curonian lagoon one of the largest coastal lagoons in Europe is located in the southeastern part of the Baltic Sea and lies along the Baltic coast of Lithuania and the Kaliningrad region of Russia. It is influenced by a discharge of the Nemunas and other smaller rivers and saline water of the Baltic Sea. The narrow (width 0.4 km, deep 8-14 m) Klaipėda Strait is the only way for fresh water run-off and brackish water intrusions. This research is focused on carbon isotope fractionations related with air - water exchange, primary production and organic carbon sedimentation, mineralization and uptake from both marine and terrestrial sources.

  19. Harmful Algae Records in Venice Lagoon and in Po River Delta (Northern Adriatic Sea, Italy)

    PubMed Central

    Bilaničovà, Dagmar; Marcomini, Antonio

    2014-01-01

    A detailed review of harmful algal blooms (HAB) in northern Adriatic Sea lagoons (Po River Delta and Venice lagoon) is presented to provide “updated reference conditions” for future research and monitoring activities. In the study areas, the high mollusc production requires the necessity to identify better methods able to prevent risks for human health and socioeconomical interests. So, an integrated approach for the identification and quantification of algal toxins is presented by combining microscopy techniques with Liquid Chromatography coupled with High Resolution Time of Flight Mass Spectrometry (HPLC-HR-TOF-MS). The method efficiency was first tested on some samples from the mentioned coastal areas, where Dinophysis spp. occurred during summer in the sites directly affected by seawaters. Although cell abundance was always <200 cells/L, the presence of Pectenotoxin-2 (PTX2), detected by HPLC-HR-TOF-MS, indicated the potential release of detectable amounts of toxins even at low cell abundance. PMID:24683360

  20. Hydrodynamics of a shallow coastal lagoon with submarine groundwater discharge: a numerical modeling exercise

    NASA Astrophysics Data System (ADS)

    Casares, R.; Marino-Tapia, I.

    2013-05-01

    Coastal lagoons are subjected to physical forces that make them vulnerable to climate change and human intervention. The karstic geology along the coastal zone of Yucatan Peninsula, Mexico, forces groundwater to discharge in the sea and coastal lagoons through underground conduits that can form small but numerous and scattered underwater springs. These freshwater inputs, along with other physical forces like ocean tides and meteorological events, can have a significant effect on the circulation and residence times in coastal lagoons. Climate change consequences such as sea level rise and changing rain patterns, as well as the increasing human impact, can cause or aggravate certain environmental effects. Since coastal lagoons provide important environmental services there is a need to understand and have predictive capability to simulate the transport processes and the forces acting on them. The present study was carried out in the coastal lagoon of Celestun, located at NW Yucatan Peninsula, a region of karstic geology. The aim of this research is to understand the barotropic hydrodynamic functioning of this shallow system, taking into account the oceanographical, meteorological and hydrological forcing. Emphasis is made on the residence times in different parts of the lagoon, and the effects of freshwater inputs. For the detailed understanding of the processes the hydrodynamic numerical model DELFT3D was implemented. The model was validated with data gathered on the field during two intensive oceanographic campaigns, which included installation of CTDs and acoustic current meters at strategic sites distributed in the system, and detailed bathymetric measurements using an echosounder coupled with a differential GPS on board of a motorboat. In order to improve model performance a sensitivity analysis to the main variables involved in the model was carried out, among them: the size of the grid cells, grid depth, time step, friction coefficients, boundary conditions

  1. MODIS/Aqua chlorophyll monitoring of the New Caledonia lagoon during the 2008 La Nina event

    NASA Astrophysics Data System (ADS)

    Dupouy, Cécile; Minghelli-Roman, Audrey; Despinoy, Marc; Röttgers, Rudiger; Neveux, Jacques; Pinazo, Christel; Petit, Michel A.

    2009-01-01

    Tropical oligotrophic coral reef lagoons are areas of high biodiversity. Chlorophyll concentration, a proxy for phytoplankton biomass and primary production, is useful to monitor the carbon balance in the context of the climate change and to validate simulations by coupled biogeochemical models. Chlorophyll monitoring by Aqua/MODIS is examined on the large tropical oligo- to mesotrophic lagoon of New Caledonia (23,900 km2). The classical OC3 algorithm developed for MODIS can only be applied in deep waters. In shallow water, when the water is clear with a weak attenuation, the bottom reflectance influences the surface reflectance and then induces an error in the chlorophyll determination. Here, a new OC3-type polynom, relating satellite reflectance ratios and chlorophyll, was determined from bio-optical data collected during a cruise (Valhybio) on the R/V Alis in the frame of the Programme National de Télédétection Spatiale. From the 22th of March to the 9th of April, data were collected during two surveys of the same network. A total of 170 in situ bio-optical measurements in the South Western and South lagoons of New Caledonia were obtained, within a 2 weeks interval (70 non-cloudy match-ups). Four Modis images were acquired during this cruise with moderate to good atmospheric conditions. The new polynom gives a RMS of 14.8% and a MNB of - 9% and gives a better representation of the "true" water column chlorophyll concentration of the New Caledonia lagoon.

  2. Moisture Effects on Nitrogen Availability in Municipal Biosolids from End-of-Life Municipal Lagoons.

    PubMed

    Jeke, Nicholson N; Zvomuya, Francis; Ross, Lisette

    2015-11-01

    Nitrogen (N) availability affects plant biomass yield and, hence, phytoextraction of contaminants during phytoremediation of end-of-life municipal lagoons. End-of-life lagoons are characterized by fluctuating moisture conditions, but the effects on biosolid N dynamics have not been adequately characterized. This 130-d laboratory incubation investigated effects of three moisture levels (30, 60, and 90% water-filled pore space [WFPS]) on N mineralization (N) in biosolids from a primary (PB) and a secondary (SB) municipal lagoon cell. Results showed a net increase in N with time at 60% WFPS and a net decrease at 90% WFPS in PB, while N at 30% WFPS did not change significantly. Moisture level and incubation time had no significant effect on N in SB. Nitrogen mineralization rate in PB followed three-half-order kinetics. Potentially mineralizable N (N) in PB was significantly greater at 60% WFPS (222 mg kg) than at 30% WFPS (30 mg kg), but rate constants did not differ significantly between the moisture levels. Nitrogen mineralization in SB followed first-order kinetics, with N significantly greater at 60% WFPS (68.4 mg kg) and 90% WFPS (94.1 mg kg) than at 30% WFPS (32 mg kg). Low N in SB suggests high-N-demanding plants may eventually have limited effectiveness to remediate biosolids in the secondary cell. While high N in PB would provide sufficient N to support high biomass yield, phytoextraction potential is reduced under dry and near-saturated conditions. These results have important implications on the management of moisture during phytoextraction of contaminants in end-of-life municipal lagoons.

  3. Wastewater treatment lagoons (ponds). (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-09-01

    The bibliography contains citations concerning the treatment and storage of wastewaters in lagoons. The design, operation, and equipment for treatment and storage techniques, and associated pretreatment processes are discussed. Included in the references are treatment of wastewaters from industrial operations. Descriptions and evaluations of specific facilities are provided. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  4. Assessment of the trophic status of four coastal lagoons and one estuarine delta, eastern Brazil.

    PubMed

    Cotovicz Junior, Luiz Carlos; Brandini, Nilva; Knoppers, Bastiaan Adriaan; Mizerkowski, Byanka Damian; Sterza, José Mauro; Ovalle, Alvaro Ramon Coelho; Medeiros, Paulo Ricardo Petter

    2013-04-01

    Anthropogenic eutrophication of aquatic ecosystems continues to be one of the major environmental issues worldwide and also of Brazil. Over the last five decades, several approaches have been proposed to discern the trophic state and the natural and cultural processes involved in eutrophication, including the multi-parameter Assessment of Estuarine Trophic Status (ASSETS) index model. This study applies ASSETS to four Brazilian lagoons (Mundaú, Manguaba, Guarapina, and Piratininga) and one estuarine delta (Paraíba do Sul River), set along the eastern Brazilian coast. The model combines three indices based on the pressure-state-response (PSR) approach to rank the trophic status and forecast the potential eutrophication of a system, to which a final ASSETS grade is established. The lagoons were classified as being eutrophic and highly susceptible to eutrophication, due primarily to their longer residence times but also their high nutrient input index. ASSETS classified the estuary of the Paraíba do Sul river with a low to moderate trophic state (e.g., largely mesotrophic) and low susceptibility to eutrophication. Its nutrient input index was high, but the natural high dilution and flushing potential driven by river flow mitigated the susceptibility to eutrophication. Eutrophication forecasting provided more favorable trends for the Mundaú and Manguaba lagoons and the Paraíba do Sul estuary, in view of the larger investments in wastewater treatment and remediation plans. The final ASSETS ranking system established the lagoons of Mundaú as "moderate," Manguaba as "bad," Guarapina as "poor," and Piratininga as "bad," whereas the Paraíba do Sul River Estuary was "good."

  5. Organotins' fate in lagoon sewage system: dealkylation and sludge sorption/desorption.

    PubMed

    Ophithakorn, Thiwari; Sabah, Aboubakr; Delalonde, Michele; Bancon-Montigny, Chrystelle; Suksaroj, Thunwadee Tachapattaworakul; Wisniewski, Christelle

    2016-11-01

    Organotin compounds (OTs) have been widely used for their biocidal properties and as stabilizers in various industrial applications. Due to their high toxicity, organotins are subject to many studies regarding their behavior in wastewater treatment plant and aquatic environment. However, few studies are available regarding their behavior in lagoon sewage system, although such treatment is commonly used for sewage treatment in low-population areas. The present study aimed at studying the fate of organotins (monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT)) in lagoon sewage system. Short-term experiments, carried out at lab scale, consisted in sampling sludge from aerobic stabilization ponds, and then quantifying sorption and desorption of the different organotin species, as well as their respective transformation, under defined operating conditions (e.g., tributyltin spike and dilution) simulating possible change in the surrounding environment of sludge in the lagoon. Results established that a very important percentage of the OTs was localized in the solid phase of the sludge (more than 98 %), whatever the operating conditions may be; however, transformation and locations of the three OT species differed according to the different conditions of sludge dilution, TBT spiking, and test duration. After dilution of lagoon sludge, TBT desorption from sludge was observed; it was supposed that dealkylation of TBT after desorption occurred rapidly and increased dissolved MBT and DBT in liquid phase; MBT sorbed subsequently on solid phase. The nature of the diluent (i.e., tap water or saline solution) appeared to slightly influence the sludge behavior. After TBT spiking, TBT was supposed to be rapidly sorbed but also transformed in DBT and MBT that would as well sorbed on the sludge, which explained the decrease of these species in the liquid phase. Tests aimed at studying long-term effect of TBT spiking demonstrated that the sorbed species could be remobilized

  6. Quantifying Methane Fluxes in Sediments from Mangrove-dominated Costal Lagoons

    NASA Astrophysics Data System (ADS)

    Chuang, P.; Young, M. B.; Paytan, A.

    2012-12-01

    Many studies have focused on methane emission from wetland sediments to the water column and atmosphere. However, there is growing evidence that organic rich, highly productive coastal areas such as mangrove-dominated lagoons and estuaries may have high rates of atmospheric methane flux, particularly in polluted areas. Dissolved methane concentrations in surface water and sediments have been measured in two coastal mangrove ecosystems (Celestún and Chelem Lagoons) on the Yucatán Peninsula, Mexico and the estimated diffusive methane fluxes to the atmosphere in both lagoons can reach to 2600 and 80 kg CH4/yr respectively with a much larger yet not quantified ebullition flux . The objectives of this study are to understand the sources and sinks for methane in sediments, how much methane is released from the sediment to water column and the relative contribution of diffusive and bubble fluxes. In addition rates/percentages of methane oxidized in the sediment and water column that lower methane flux to the atmosphere are quantified. Sedimentary geochemical data (methane, sulfate, chloride, particulate organic carbon (POC) and stable carbon isotopes of headspace methane) from the two lagoons were also measured to determine the impact of different salinities and degrees of pollution on POC mineralization and methane fluxes. Stable carbon isotopes of methane data indicate gas productions mainly by CO2 reduction with minor acetate fermentation signatures. A numerical transport-reaction model will be apply to the data to estimate sulfate reduction, methane oxidation and production rates and advective methane fluxes. The modeled results will be compared to methane bubble fluxes measured by flux chambers to obtain total methane emissions from sediment and discuss the role of methane from mangriove areas in impacting global climate change.

  7. Environmental Dynamics as a Structuring Factor for Microbial Carbon Utilization in a Subtropical Coastal Lagoon

    PubMed Central

    Alonso, Cecilia; Piccini, Claudia; Unrein, Fernando; Bertoglio, Florencia; Conde, Daniel; Pernthaler, Jakob

    2013-01-01

    Laguna de Rocha belongs to a series of shallow coastal lagoons located along South America. It is periodically connected to the sea through a sand bar, exhibiting a hydrological cycle where physicochemical and biological gradients are rapidly established and destroyed. Its most frequent state is the separation of a Northern zone with low salinity, high turbidity and nutrient load, and extensive macrophyte growth, and a Southern zone with higher salinity and light penetration, and low nutrient content and macrophyte biomass. This zonation is reflected in microbial assemblages with contrasting abundance, activity, and community composition. The physicochemical conditions exerted a strong influence on community composition, and transplanted assemblages rapidly transformed to resembling the community of the recipient environment. Moreover, the major bacterial groups responded differently to their passage between the zones, being either stimulated or inhibited by the environmental changes, and exhibiting contrasting sensitivities to gradients. Addition of allochthonous carbon sources induced pronounced shifts in the bacterial communities, which in turn affected the microbial trophic web by stimulating heterotrophic flagellates and virus production. By contrast, addition of organic and inorganic nutrient sources (P or N) did not have significant effects. Altogether, our results suggest that (i) the planktonic microbial assemblage of this lagoon is predominantly carbon-limited, (ii) different bacterial groups cope differently with this constraint, and (iii) the hydrological cycle of the lagoon plays a key role for the alleviation or aggravation of bacterial carbon limitation. Based on these findings we propose a model of how hydrology affects the composition of bacterioplankton and of carbon processing in Laguna de Rocha. This might serve as a starting hypothesis for further studies about the microbial ecology of this lagoon, and of comparable transitional systems. PMID

  8. Reconstruction of historical atmospheric deposition of DDT in the Zempoala Lagoon, in the center of Mexico

    USGS Publications Warehouse

    van, Afferden M.; Hansen, A.M.; Fuller, C.C.

    2005-01-01

    Historical trend in deposition of DDT and its metabolites has been reconstructed by analyzing sediment cores of the Zempoala Lagoon, in the center of Mexico. The small watershed of this mountain lagoon is closed, and it is located between 2.800 and 3.700 masl. It ls neither affected by agriculture nor by permanent populations. The Zempoala Lagoon has an average depth of 3.9 mand a maximum depth of 8.8 m. Sediments were extracted with a eore sampler and analyzed by isotope methods (137CS and 2'OPb) for dating. Average sedimentation rate was determined in 0.129 9 cm" yr', corresponding to a maximum age of the 44 cm eore of approximately 60 years. The first presence of total-DDT oecurs in a depth between 28 and 32 cm of the sediment profile, corresponding to the 1960's, with a concentration of 5.3 I1g kg-'. The maximum eoncentration of total-DDT (13.0I1g kg-') occurs in sediment layers representing the late 1970's and beginning 1980's. More recently the concentration decreases towards the present concentration of 1.6 I1g kg-'. This concentration is below most DDT levels reported in recent sediment studies in the USA. The results indicate that the Zempoala Lagoon represents a natural reeipient for studies of the reconstruction of historical trends of atmospheric contaminant deposition in this region. The limitations of the methodology applied, due to the influenee of biodegradation on the definition of correct historical coneentrations of DDT depositions, are demonstrated.

  9. Application of Potential Non-Point Pollution Index For An Urban Watershed: Istanbul, Kucukcekmece Lagoon

    NASA Astrophysics Data System (ADS)

    Musaoglu, N.; Dikerler, T.; Seker, D. Z.; Ustun, B.

    2011-12-01

    Istanbul is a major city with more than 15 million population and limited water resources. Besides, its urbanized area has been rapidly expanding for more than 30 years. Küçükçekmece Lagoon, as a potential RAMSAR site with its rich natural diversity and housing asset for birds, has been suffering from urbanization and industrial stress. With Sazlidere Dam constructed on the Lagoon's most important creek which supplies fresh water, Küçükçekmece Basin has almost 600 km2 wide area. Due to dam operation which cuts fresh water input down, water quality of the Küçükçekmece Lagoon has been deteriorating, as well as other antropogenic impacts. Potential non-point pollution index (or PNPI) is based on land use, soil and topographic data and aims to highlight the potentially polluting areas in a watershed. Denoting those areas, PNPI puts an assessment of the pressure exerted on the water bodies by different land uses. This index calculates different layers in order to represent run-off, land cover effect, and the distance of each polluting source (or pixels) in the study area. By the multiplication of those layers under GIS, a new data layer is produced showing the polluting potential of each pixel on the study area. For by Küçükçekmece Basin, Landsat ETM satellite images have been taken and its land use produced by unsupervised classification. Using this updated data, land use - land cover indicator has been calculated for the basin. Topography is another fact that is needed to produce both run-off indicator and distance indicator and it is generated by elevation data with 5m resolution. By integrating these indicator layers, PNPI analysis layer has been produced for Küçükçekmece Lagoon watershed.

  10. Optical characterization and assessment of ocean colour algorithms in Chilika Lagoon

    NASA Astrophysics Data System (ADS)

    Lotliker, Aneesh A.; Sahoo, Subhashree; Baliarsingh, S. K.; Parida, C.; Sahu, K. C.

    2016-05-01

    Asia's largest brackish water ecosystem, Chilika lagoon, supports livelihood of millions of inhabitants and also known to be bio-geo-chemically dynamic. This demands continuous monitoring of lagoon for which optical remote sensing may be crucial. The in situ bio-optical parameters were analyzed in two sectors (Outer Channel: OC and Southern Sector: SS) of Asia's largest brackish water ecosystem, Chilika lagoon. The spectral Remote Sensing Reflectance (Rrs) ranged from 0.003 to 0.02sr-1 in OC whereas in SS it was between 0.003 and 0.028sr-1. The minimum Rrs was at 400nm that gradually increased with a peak at 580nm and subsequently decreased towards longer wavelength. Rrs exhibited similar pattern in both the sectors from 400 to 600nm. Beyond this wavelength, Rrs was relatively higher in SS. The shifting of peak towards longer wavelength could be attributed to high absorption due to chlorophyll-a (chl-a) and chromophoric dissolved organic matter (CDOM) that varied largely between sectors with relatively higher concentration of chl-a in OC and CDOM in SS. Further, we modelled chl-a by seven ocean colour algorithms (OC4, OC4E, OC4O, OC3M, OC3V, OC3C and OCMO2) using in situ Rrs. The modelled chl-a was overestimating in situ at all stations due to high concentration of CDOM contaminating chl-a signals. However in OC, in situ and modelled chl-a followed the same trend (R2=0.88 to 0.90) probably due to strong co-variance of chl-a with CDOM. The analysis of this study points out towards the requirement for sector specific bio-optical algorithm for accurate chl-a retrieval for synoptic monitoring of lagoon health.

  11. Reconstructing the cosmogenic 21Ne inventory of Neogene sedimentary sequences

    NASA Astrophysics Data System (ADS)

    Stuart, Finlay; Sinclair, Hugh; McCann, Louise

    2016-04-01

    The cosmogenic radionuclides, in particular 10Be, have found use in modern sediments as a way of determining the erosion rate of river catchments. Cosmogenic 21Ne in quartz is easier and faster to measure than 10Be and has the potential to record erosion rates back 10s million years. However the routine use of cosmogenic 21Ne in quartz sand is hampered by ubiquitous nucleogenic 21Ne. When the eroding lithology can be identified it is possible to measure the nucleogenic in samples that are shielded from cosmic rays and correct for it in exposed bedrock [1]. However, identifying the lithologies that contributes quartz sand in large river catchments, and determining precise nucleogenic contributions is more problematic. The North and South Platte rivers drain early Prototerozoic lithologies of the Laramie and Front Ranges in the high Rockies of Wyoming. They have deposited several km of coarse clastic fluvial deposits on the Great Plains of Nebraska and Colorado up to 200 km from the mountain front. Quartz from shielded samples of granite and gneiss - the dominant quartz-bearing rocks - has high concentrations of nucleogenic 21Ne (60-140 e6 atoms/g). The 21Ne concentration in modern sand from the river (n=10) overlaps that measured in the shielded granite and gneiss. The sand data rarely lie on the air-spallation mixing line in the Ne three isotope plot indicating that it is dominantly derived from the granite and gneiss and has no resolvable cosmogenic 21Ne. Building on previous studies of cosmogenic 21Ne in pebbles [2] we have started a programme of analysis of pebbles derived from the Medicine Bow quartzite that are abundant throughout the Cenozoic alluvial sequence. Nucleogenic 21Ne in shielded quartzite is lower than granites (3-7 e6 atoms/g, n=4) and the data tend to lie on the air-spallation mixing line. All pebbles (n=14) from modern sediments analysed so far contain 2-80 times more excess 21Ne than the highest shielded quartzite suggesting that cosmogenic 21

  12. Genotoxicity in two bivalve species from a coastal lagoon in the south of Portugal.

    PubMed

    Almeida, Catarina; Pereira, Catarina G; Gomes, Tânia; Cardoso, Cátia; Bebianno, Maria João; Cravo, Alexandra

    2013-08-01

    DNA damage was evaluated by comet assay in the haemolymph of two bivalve species Ruditapes decussatus and Mytilus galloprovincialis from the Ria Formosa lagoon (south Coast of Portugal). Clams and mussels were sampled from sites close to each other to determine interspecific responses to similar environmental conditions, considering also seasonal and gender differences. Coupled with genotoxic effect, another damage biomarker (lipid peroxidation) was analysed to verify if the conditions that instigate DNA damage can be related with injury to cell membranes. For both species, DNA damage was low, reflecting the low levels of genotoxic contaminants in the lagoon, and no interspecific differences were found. However, seasonal differences were established for both bivalve species, reflecting higher environmental stress in summer. Regarding gender susceptibility, only clams showed differences in percentage of Tail DNA, with females more sensitive to DNA damage than males. Additionally, results for clams point out that factors responsible for LPO may not be the same as those causing genotoxicity. This study demonstrated that DNA damage is a sensitive biomarker to discriminate spatial, temporal and gender differences, being an appropriate biomarker for genotoxicity evaluation even in places of low contamination, such as the Ria Formosa lagoon.

  13. Identifying rainfall effects in an arid Gulf of California coastal lagoon.

    PubMed

    Mendoza-Salgado, Renato A; Lechuga-Devéze, Carlos H; Ortega-Rubio, Alfredo

    2005-04-01

    At Ensenada de La Paz, a coastal lagoon on the western side of the Gulf of California, nutrient and salinity data before and after rain events were evaluated using a mass balance model to estimate the exchange of conservative and non-conservative variables with the adjacent sea. Surface salinity, nitrogen (N-NO3, N-NO2), and phosphorus (PO4) were used in the model to obtain the hydraulic balance, water residence time, and nitrogen and phosphorus fluxes. Results showed that residual volume was mainly influenced by evaporation. Rainfall and runoff increased the mixed volume and reduced water residence time. Pre-rainfall hydraulic balance conditions were reestablished about 10 days after a rain storm. Rainwater inputs also modified the quality of the coastal lagoon: the pre-rainfall scenario showed that more nitrogen is consumed than produced, and there is a phosphorus sufficiency. A rain disturbance induces a nitrogen and phosphorus increase. Eleven days after a rain storm, nitrogen and phosphorus levels did not return to the pre-rainfall scenario. Rain disturbances in arid zone coastal lagoons modify their water quality and exchange with the adjacent ocean; some management strategies are suggested.

  14. Investigating flight response of Pacific brant to helicopters at Izembek Lagoon, Alaska by using logistic regression

    USGS Publications Warehouse

    Erickson, Wallace P.; Nick, Todd G.; Ward, David H.; Peck, Roxy; Haugh, Larry D.; Goodman, Arnold

    1998-01-01

    Izembek Lagoon, an estuary in Alaska, is a very important staging area for Pacific brant, a small migratory goose. Each fall, nearly the entire Pacific Flyway population of 130,000 brant flies to Izembek Lagoon and feeds on eelgrass to accumulate fat reserves for nonstop transoceanic migration to wintering areas as distant as Mexico. In the past 10 years, offshore drilling activities in this area have increased, and, as a result, the air traffic in and out of the nearby Cold Bay airport has also increased. There has been a concern that this increased air traffic could affect the brant by disturbing them from their feeding and resting activities, which in turn could result in reduced energy intake and buildup. This may increase the mortality rates during their migratory journey. Because of these concerns, a study was conducted to investigate the flight response of brant to overflights of large helicopters. Response was measured on flocks during experimental overflights of large helicopters flown at varying altitudes and lateral (perpendicular) distances from the flocks. Logistic regression models were developed for predicting probability of flight response as a function of these distance variables. Results of this study may be used in the development of new FAA guidelines for aircraft near Izembek Lagoon.

  15. Ecosystem level assessment of the Grand Calumet Lagoons, Indiana Dunes National Lakeshore

    SciTech Connect

    Stewart, P.M.

    1995-12-31

    The Grand Calumet Lagoons make up the eastern section of the Grand Calumet River (GCR), Indiana Harbor and Ship Canal and nearshore Lake Michigan Area of Concern (AOC). The GCR AOC is the only one of the 42 Great Lakes Areas of Concern identified by the International Joint Commission with all 14 designated uses classified as impaired. Included within the boundaries of the Indiana Dunes National Lakeshore (INDU), is the central section of the Grand Calumet Lagoons. A number of biotic and abiotic factors were tested to determine the effects of an industrial landfill that borders the lagoons to assess the potential impact on park resources. Analysis included water quality testing, assessments of macroinvertebrate, fish, algae and aquatic plant communities and contaminant concentrations in water, sediment and plant and fish tissue. Surface water testing found very few contaminants, but significantly higher nutrient levels were found in the water column closest to the landfill. Macroinvertebrate, aquatic plant and fish communities all showed significant impairment in relationship to their proximity to the landfill. Aquatic plant growth habit became limited next to the landfill with certain growth habits disappearing entirely. Aquatic plants collected close to the landfill had high concentrations of several heavy metals in their stems and shoots. Using the index of biotic integrity (IBI), fish community assessment indicated impairment in the areas adjacent to the landfill. Sediments tested at one site had over 12% polycyclic aromatic hydrocarbons (PAH) and carp (Cyprinus carpio) collected from this site had whole fish tissue concentrations over 1 mg/kg PAH.

  16. Health assessment for William Dick Lagoons, Honeybrook, Pennsylvania, Region 3. CERCLIS No. PAD980537773. Preliminary report

    SciTech Connect

    Not Available

    1988-09-30

    The William Dick Lagoon site consists of three unlined lagoons (approximately 2.5 acres total area) which previously contained over four million gallons of rinse water from cleaning chemical tank trailers. In 1970, two of the lagoons breached and released approximately 300,000 gallons of wastewater into the nearby area and a small tributary. Trichloroethylene, toluene, 4,4-DDE, and polynuclear aromatic hydrocarbons have been reported in the soil on the site. Trichloroethylene was detected in a nearby spring, previously used as a water source by a small number of residents. Potential human exposure pathways include ingestion of contaminated water, dermal exposure to contaminated water and soil, and inhalation of contaminated dust and organics in the contaminated groundwater. The site is considered to be of potential public health concern because of the risk to human health caused by the possibility of exposure to hazardous substances. However, it does not appear that a human population is currently exposed to site contaminants at levels of health concern.

  17. Removal of human enteric viruses and indicator microorganisms from domestic wastewater by aerated lagoons.

    PubMed

    Locas, Annie; Martinez, Veronica; Payment, Pierre

    2010-02-01

    Aerated lagoons offer a low-cost and simple approach to treating domestic wastewater in small municipalities. The objective of the current study was to evaluate, for each cell in the lagoons, the removal of indicator microorganisms and human enteric viruses under warm (summer) and cold (early spring) conditions. The two sites are located in southwest Quebec, Canada. Samples were assayed for thermotolerant coliforms, enterococci, Clostridium perfringens, somatic and male-specific coliphages, and culturable human enteric viruses (HEV). The results show higher removal under warm ambient conditions for all microorganisms. Thermotolerant coliforms and enterococci were removed to a greater extent than C. perfringens and HEV. HEV removal was only observed in warm ambient conditions. The removal of coliphages was different from the observed removal of HEV. The use of coliphages as surrogates for HEV has been proposed, but this does not seem appropriate for aerated lagoons, as the removal of coliphages overestimates the removal of HEV. Given the low observed removal of HEV during this study, the effluents remain a significant source of pathogens that can affect drinking water treatment plants drawing their raw water from receiving streams. Ultraviolet disinfection of treated wastewater effluent is a possible solution.

  18. Mercury in sediments and Nassarius reticulatus (Gastropoda Prosobranchia) in the southern Venice Lagoon.

    PubMed

    Berto, D; Giani, M; Covelli, S; Boscolo, R; Cornello, M; Macchia, S; Massironi, M

    2006-09-01

    The southern basin of the Venice Lagoon has been the focus of fewer studies concerning contamination from heavy metals than the northern and central basins. A recent increase in urban waste waters from Chioggia town, as well as dockyards, shipping and fishing activities, affect this part of the lagoon. The aim of this study was to investigate the total mercury (THg) incidence in sediments and Nassarius reticulatus gastropods in order to assess its distribution and evaluate the level of contamination. THg concentration measured in bottom sediments ranged between 0.1 and 3.4 mg/kg d. wt. The enrichment factor (EF) showed high values (avg. 30, max 49) near the dockyards of Chioggia; the lowest (avg. 9, max 17) were found in the coastal marine sediments near the port entrance of the southern basin. THg in marine scavenger gastropods accumulated in N. reticulatus with concentrations falling within the range of 0.3-1.3 mg/kg d. wt. A positive correlation was found between THg concentration in sediments and in N. reticulatus in all sites, excluding the dockyards. A first local cause for mercury pollution might be attributed to the antifouling paints used in great quantity in the recent past near the town of Chioggia. Moreover, fine suspended sediments associated with tidal flushing are suggested as possibly being the vehicle for pollutant dispersal from the Marghera industrial area to the whole of Venice's lagoon.

  19. Habitat distribution model for European flounder juveniles in the Venice lagoon

    NASA Astrophysics Data System (ADS)

    Zucchetta, Matteo; Franco, Anita; Torricelli, Patrizia; Franzoi, Piero

    2010-07-01

    In order to identify nursery habitats for Platichthys flesus in the Venice lagoon we developed a generalized additive model relating juvenile flounder's distribution to environmental variables. A field survey was conducted between March 2004 and June 2005 and between February and October 2008 in the central and Northern sub-basins of the lagoon. Each station was sampled by means of a beach seine net and characterized collecting the main chemico-physical variables, such as water temperature, salinity, turbidity, dissolved oxygen content and bottom grain size. Main winds fetches were also considered, and estimated in a GIS environment. A logistic model was fitted, and evaluated on an independent dataset. The response curves allowed to identify the role of the environmental parameters in explaining the distribution of the juvenile flounder: turbidity, salinity and sand content revealed to be the most important factors, showing the preference for mesohaline turbid waters together with a low sand content of the sediment. The application of this model to continuous surfaces of the environmental variables allowed the creation of potential habitat distribution maps. In this way it has been possible to recognize several areas covering a key role for the juveniles of flounder, located mainly in the inner part of the lagoon.

  20. Water Hyacinths for Upgrading Sewage Lagoons to Meet Advanced Wastewater Treatment Standards, Part 1

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.; Mcdonald, R. C.

    1975-01-01

    Water hyacinths, Eichhornia crassipes Mart. Solms, have demonstrated the ability to function as an efficient and inexpensive final filtration system in a secondary domestic sewage lagoon during a three month test period. These plants reduced the suspended solids, biochemical oxygen demanding substances, and other chemical parameters to levels below the standards set by the state pollution control agency. The water hyacinth-covered secondary lagoon utilized in this experiment had a surface area of 0.28 hectare (0.70 acre) with a total capacity of 6.8 million liters (1.5 million gallons), receiving an inflow of 522,100 liters (115,000 gallons) per day from a 1.1 hectare (3.8 acre) aerated primary sewage lagoon. These conditions allowed a retention time of 14 to 21 days depending on the water hyacinth evapotranspiration rates. The desired purity of final sewage effluent can be controlled by the water hyacinth surface area, harvest rate, and the retention time.

  1. Hurricane impact on lagoonal reefs - implications for recognition of ancient storm deposits

    SciTech Connect

    Bonem, R.M.

    1985-01-01

    During August 1080, Hurricane Allen passed along the north coast of Jamaica. Although several previous investigations have documented the effects of this hurricane on the fore reef and reef crest, this study presents the first detailed description of the storm impact on lagoonal patch reefs in Discovery Bay. In contrast to the damage described on the fore reef and reef crest, the patch reefs received only minor temporary damage to reef framework due to breakage and increased sedimentation. These effects could be recognized only by examination of bathymetric and zonal maps constructed during the last 10 years. However, hurricane impact on the sedimentologic record was readily observed in cores taken along transects of lagoonal patch reefs. Although in general, shallow reef zones had abnormally great amounts of fine sediment and deeper zones showed increased coarse material, other patterns could be documented and made recognition of storm deposits and distinction of these deposits from artificial disturbance relatively easy. Because lagoonal patch reefs may serve as models for many ancient bioherms, this study provides new evidence that may be used to recognize ancient storm deposits associated with bioherms in carbonate mud environments.

  2. Multivariate analysis of potentially toxic metals in sediments of a tropical coastal lagoon.

    PubMed

    Oyeyiola, A O; Davidson, C M; Olayinka, K O; Oluseyi, T O; Alo, B I

    2013-03-01

    Surface sediments collected from the Lagos Lagoon, Nigeria, and three adjoining rivers were analysed for their physicochemical properties and pseudo-total concentration of the potentially toxic metals (PTM) Cd, Cr, Cu, Pb and Zn. The concentration of the PTM varied seasonally and spatially. Odo-Iyaalaro was observed to be the most polluted river, with highest concentrations of 42.1 mg kg(-1), 102 mg kg(-1), 185 mg kg(-1), 154 mg kg(-1) and 1040 mg kg(-1) of Cd, Cr, Cu, Pb and Zn, respectively, while Ibeshe River was the least contaminated, apart from a site affected by Cu from the textile industry. Some of the sediments were found to be above the consensus-based probable effect concentrations and Dutch sediment guideline for metals. Overall metal concentrations were similar to those reported for other tropical lagoon and estuarine systems affected by anthropogenic inputs as a result of rapid urbanisation. Due to the large number of samples, principal component analysis was used to examine relationships within the data set. Generally, sediments collected during the dry season were observed to have higher concentration of PTM than those collected during the rainy season. This means that PTM could accumulate over a prolonged period and then be released relatively rapidly, on an annual basis, into tropical lagoon systems.

  3. Do pharmaceuticals bioaccumulate in marine molluscs and fish from a coastal lagoon?

    PubMed

    Moreno-González, R; Rodríguez-Mozaz, S; Huerta, B; Barceló, D; León, V M

    2016-04-01

    The bioaccumulation of 20 pharmaceuticals in cockle (Cerastodema glaucum), noble pen shell (Pinna nobilis), sea snail (Murex trunculus), golden grey mullet (Liza aurata) and black goby (Gobius niger) was evaluated, considering their distribution throughout the Mar Menor lagoon and their variations in spring and autumn 2010. The analytical procedure was adapted for the different matrices as being sensitive and reproducible. Eighteen out of the 20 compounds analysed were found at low ngg(-1) in these species throughout the lagoon. Hydrochlorothiazide and carbamazepine were detected in all species considered. The bioaccumulation of pharmaceuticals was heterogeneous in the lagoon, with a higher number of pharmaceuticals being detected in fish (18) than in wild molluscs (8), particularly in golden grey mullet muscle (16). В-blockers and psychiatric drugs were preferentially bioccumulated in fish and hydrochlorothiazide was also confirmed in caged clams. The higher detection frequency and concentrations found in golden grey mullet suggested that mugilids could be used as an indicator of contamination by pharmaceuticals in coastal areas. To the best of our knowledge, this is the first study that shows data about hydrochlorothiazide, levamisole and codeine in wild marine biota.

  4. Benthic macrofauna and sediment reworking quantification in contrasted environments in the Thau Lagoon

    NASA Astrophysics Data System (ADS)

    Duport, E.; Gilbert, F.; Poggiale, J.-C.; Dedieu, K.; Rabouille, C.; Stora, G.

    2007-04-01

    As part of the Microbent-PNEC Program: "Biogeochemical processes at the water-sediment interface in eutrophicated environment", the aim of this work was to specifically investigate and quantify the relationships between macrobenthos and sediment reworking in the Thau Lagoon in order to provide information on the potential contaminant distribution and movements at the water-sediment interface. In order to achieve this, three cores were sampled at two stations (in the central part of the Thau Lagoon and near the shellfish farming zone) in the Thau Lagoon, in December 2001, April 2002, August 2002, January 2003 and May 2003. On the basis of quantification of macrobenthos and sediment reworking, evidence is provided of: (1) similar sediment mixing intensities for different species composition at the two stations; (2) the major role of functional bioturbation groups (e.g., biodiffusors and gallery-diffusors) modulated by seasonal variability on sediment mixing; (3) an increase of intensity in summer suggesting potentially different patterns of redistribution, bioaccumulation and chemical fate (e.g., speciation) of deposited contaminants.

  5. Microbial community composition of Tirez lagoon (Spain), a highly sulfated athalassohaline environment

    PubMed Central

    2013-01-01

    Background The aim was to study the seasonal microbial diversity variations of an athalassohaline environment with a high concentration of sulfates in Tirez lagoon (La Mancha, Spain). Despite the interest in these types of environments there is scarce information about their microbial ecology, especially on their anoxic sediments. Results We report the seasonal microbial diversity of the water column and the sediments of a highly sulfated lagoon using both molecular and conventional microbiological methods. Algae and Cyanobacteria were the main photosynthetic primary producers detected in the ecosystem in the rainy season. Also dinoflagelates and filamentous fungi were identified in the brines. The highest phylotype abundance in water and sediments corresponded to members of the bacterial phylum Proteobacteria, mainly of the Gamma- and Alphaproteobacteria classes. Firmicutes and Actinobacteria were isolated and identified in Tirez brines and sediment samples. Halophilic sulfate reducing Deltaproteobacteria were also detected (Desulfohalobium). Conclusions Important differences have been found in the microbial diversity present in the Tirez water column and the sediments between the wet and dry seasons. Also the Tirez lagoon showed a high richness of the bacterial Alpha- and Deltaproteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and for the archaeal Euryarchaeota. PMID:24083554

  6. Use of different intertidal habitats by faunal communities in a temperate coastal lagoon

    NASA Astrophysics Data System (ADS)

    Almeida, Cheila; Coelho, Rui; Silva, Marco; Bentes, Luís; Monteiro, Pedro; Ribeiro, Joaquim; Erzini, Karim; Gonçalves, Jorge M. S.

    2008-11-01

    The faunal communities of four intertidal habitats namely sand, mud, seagrass ( Zostera noltii) and seagrass patches (mixSM) of a temperate coastal lagoon, Ria Formosa (southern Portugal), were sampled. A total of 47 species were taken in 428 bottomless drop sampler samples, with the highest number of species and the more commonly occurring species belonging to the Mollusca phylum. The dominance of these gastropod species underlines the importance of the grazing food chain in these habitats. Bittium reticulatum was the most abundant species, being especially abundant in the seagrass habitat. The most frequent and highest biomass species in the community was Carcinus maenas, a predator that makes use of the available resources and that is adapted to the highly variable intertidal environment. Pomatoschistus microps was the most abundant fish species, with highest densities in the mud habitat, which demonstrates an ability to occupy a low depth area. The seagrass habitat had the highest diversity, abundance and biomass, followed by the mixSM habitat and was different from all the others. Assemblages were highly influenced by the presence of vegetation, providing forage and refuge from predation. A well defined summer group was identified in all habitats. These results highlight the importance of seagrass beds and the idea that their decrease implies the decrease of lagoon production through the impoverishment of the trophic structure of the lagoon.

  7. Water quality of a coastal lagoon (ES, Brazil): abiotic aspects, cytogenetic damage, and phytoplankton dynamics.

    PubMed

    Duarte, Ian Drumond; Silva, Nayara Heloisa Vieira Fraga; da Costa Souza, Iara; de Oliveira, Larissa Bassani; Rocha, Lívia Dorsch; Morozesk, Mariana; Bonomo, Marina Marques; de Almeida Pereira, Thaís; Dias, Mauro Cesar; de Oliveira Fernandes, Valéria; Matsumoto, Silvia Tamie

    2017-03-14

    Assessment of water resources requires interdisciplinary studies that include multiple ecosystem aspects. This study evaluated the water quality of Juara Lagoon (ES, Brazil) based on physical and chemical variables, cytogenetic responses in Allium cepa and phytoplankton dynamics. Three sampling sites were defined and water samples were collected during two sampling periods. Analyses such as determination of photic zone, conductivity, and concentrations of nutrients and metals were conducted as well as cytotoxic, mutagenic, and genotoxic potentials using A. cepa test. The main attributes of phytoplankton community, such as total richness, total density, density by class, dominance, and diversity, were also evaluated. Results have revealed that Juara Lagoon has signs of artificial eutrophication at two sampling sites due to high levels of total phosphorus and ammonia nitrogen. Cytotoxic, genotoxic, and mutagenic potentials were detected as well as high concentrations of Fe and Mn. Furthermore, 165 phytoplankton taxa were recorded, with highest richness in Chlorophyceae and Cyanophyceae classes. In addition, Cyanophyceae presented as the highest density class. A. cepa test and phytoplankton community evaluation indicated that the ecological quality of Juara Lagoon is compromised.

  8. Vegetation cyclic shift in eutrophic lagoon. Assessment of dystrophic risk indices based on standing crop evaluations

    NASA Astrophysics Data System (ADS)

    Lenzi, Mauro; Renzi, Monia; Nesti, Ugo; Gennaro, Paola; Persia, Emma; Porrello, Salvatore

    2013-11-01

    Orbetello lagoon (Tuscany, Italy) is a meso-eutrophic, shallow-water ecosystem which has undergone cyclic shifts in macrophyte dominance since 1970. Field data on the total standing crops of Chlorophyceae and Rhodophyceae (from 1983 to 2011) and Angiospermae (seagrass; from 1998 to 2007), produced each year by the ecosystem, was acquired. A general lagoon environment quality score (decay level DL, categories 0-4) was attributed (a posteriori) for each annual dataset examined. Univariate and multivariate statistical analyses were used to relate total macrophyte standing crops of 29 years of monitoring to the general quality score. Two indices were proposed (Abundance of Macroalgae Index, AMI, and Abundance of Seagrass Index, ASI, the latter in two versions, ASI-1 and ASI-2) and tested against DL. The results showed that biomass data did not accurately describe general environmental quality of the lagoon ecosystem, whereas the indices gave a better fit. AMI showed the best performance, demonstrating that macroalga data was much more informative than seagrass data. Values of AMI over 4.0 were significantly associated with critical general quality scores (DL > 2).

  9. [Distribution of aquatic birds in oxidation lagoons of La Paz city in South Baja California, Mexico].

    PubMed

    Zamora-Orozco, Elvia Margarita; Carmona, Roberto; Brabata, Georgina

    2007-06-01

    Taxonomic composition, spatial and temporal distribution of aquatic birds in oxidation lagoons (LO) of La Paz city in south Baja California, Mexico, were determined during 24 censuses realized in two-week intervals (April/98-March/99). There are five lagoons of5 Ha each and 17 ha of terrains constantly flooded that serve as feeding areas for cattle and birds. One hundred twenty three species were observed, 75 of which were aquatic birds. A total of 46 041 observations were made (average 1 918 birds/census). Richness and abundance of aquatic birds were influenced mainly by migration of anatids and sandpipers. The first group had the greatest abundance due to its affinity towards fresh water bodies. The terrains were the favorite sites of dabbling ducks (Anas) and sandpipers. In contrast, two of the most abundant species (Oxyura jamaicensis, 12.5% of all species, and Fulica americana, 8.8 %) restricted their presence to the oxidation lagoons. LO presented a bird structure of its own and atypical, according to the dryness of the region.

  10. Lagoon and tidal flat sedimentation of the Upper Devonian Nisku Formation in southern Alberta

    SciTech Connect

    Slingsby, A. ); Kissling, D.L. )

    1991-06-01

    Since 1985, 26 oil pools containing 64 million bbl of oil in place have been discovered in the Nisku Formation in southern Alberta. The thoroughly dolomitized Nisku Formation varies from 20 to 30 m thick in southern Alberta and northern Montana. It overlies anhydrites and shaly carbonates of the Southesk or Duperow formations and underlies anhydrites of the Stettler or Potlatch formation. Burrowed, nodular-bedded skeletal wackestone, deposited over a shallow marine shelf, forms the basal Nisku Formation. These strata are succedded diachronously and unconformably by several tidal-flat and lagoon facies that include (1) southeast-thinning washover fans of cross-bedded peloidal grainstone; (2) laminated mudstone to current-bedded peloidal and intraclastic grainstone sourced within the lagoon; (3) stromatolitic mudstones; (4) laminated anhydrite beds precipitated during salina episodes; (5) Amphipora and brachiopod wackestones and thrombolites containing Renalcis, serpulids, and ostracoes, marking a brief marine invasion; and (6) brackish or freshwater shale and mudstone containing fragmented lycopod leaves and antiarch fish remains. These sediments are overlain by cross-bedded, peloidal, and calcisiltite grainstone and stromatolitic mudstone deposited in tidal channels and over shoals. All facies have been subjected to periodic subareal exposure which has produced leaching, solution collapse brecciation, teepee structures, and nodular-mosaic and void-filling anhydrite. Permeable reservoirs exist where leached, dolomitized tidal flat and lagoon sediments contain intercrystalline and pelmoldic porosity and little anhydrite cement.

  11. [Population ecology of Crocodylus acutus (Reptilia: Crocodylidae) in Palmasola lagoon, Oaxaca, Mexico].

    PubMed

    García-Grajales, Jesús; Silva, Alejandra Buenrostro

    2014-03-01

    Population ecology of Crocodylus acutus (Reptilia: Crocodylidae) in Palmasola lagoon, Oaxaca, Mexico. Abundance and population structure are important parameters to evaluate and compare the conservation status of a population over time in a given area. This study describes the population abundance and structure of Crocodylus acutus in Palmasola lagoon, Oaxaca. The field works consisted of night surveys during the new moon phase, between the 21:00 and 24:00h. These were conducted during the dry and wet seasons and counted the number of individuals to obtain population estimates. Recorded encounter rates ranged from 32 to 109.3ind./ km in 40 journeys deployed with an average time of 18 minutes browsing. The estimated population size using the Messel's model ranged from 32.7 to 93 individuals. For both seasons, there was a marked dominance of subadults, followed by juveniles and to a lesser extent adult individuals, as well as undetermined individuals (i.e. unknown body/size/length), in both seasons. There was also a significant association with mangrove areas (26.1%) by juveniles; the subadults's individual use of superficial water (22.7%) and mangrove areas (15.7%); meanwhile the adults were observed on superficial water (9.7%). This information contributes to our understanding of the population ecology of C. acutus in the Palmasola lagoon where the estimated population size seems to show higher values when compared to other reports in the country.

  12. Copepod community succession during warm season in Lagoon Notoro-ko, northeastern Hokkaido, Japan

    NASA Astrophysics Data System (ADS)

    Nakagawa, Yoshizumi; Ichikawa, Hideaki; Kitamura, Mitsuaki; Nishino, Yasuto; Taniguchi, Akira

    2015-06-01

    Lagoon Notoro-ko, located on the northeastern coast of Hokkaido, Japan, and connected to the Okhotsk Sea by a human-made channel, is strongly influenced by local hydrography, as water masses in the lagoon are seasonally influenced by the Soya Warm Current and the East Sakhalin Current. We here report on the succession of copepod communities during the warm season in relation to water mass exchange. Copepods were categorized into four seasonal communities (spring/early-summer, mid-summer, late-summer/fall, and early-winter) via a cluster analysis based on Bray-Curtis similarities. Spring/early-summer and early-winter communities were characterized by the temperate-boreal calanoid Pseudocalanus newmani, comprising 34.9%-77.6% of the total abundance of copepods during times of low temperature/salinity, as influenced by the prevailing East Sakhalin Current. Late-summer/fall communities were characterized by the neritic warm-water calanoid Paracalanus parvus s.l., comprising 63.9%-96.3% of the total abundance, as influenced by the Soya Warm Current. Mid-summer communities comprised approximately equal abundances of P. parvus, Eurytemora herdmani, Scolecithricella minor, and Centropages abdominalis (12.8%-28.2%); this community is transitional between those of the spring/early-summer and late-summer/fall. Copepod community succession in Lagoon Notoro-ko can be largely explained by seasonal changes in water masses.

  13. Support mechanisms for oil spill accident response in costal lagoon areas (Ria de Aveiro, Portugal)

    NASA Astrophysics Data System (ADS)

    Oliveira, Eduardo R.; Silveira, Bruno; Alves, Fátima L.

    2014-10-01

    Oil spill accidents can be caused by several risk factors associated to maritime transport and port activities, which cannot always be predicted or controlled. Therefore, it is essential to support prevention and contingency plans, whose effectiveness is crucial to produce adequate responses and minimize resulting impacts. Ria de Aveiro (Portugal) is a wide coastal lagoon, within a densely populated area, representing a concentration of important biodiversity resources and several economic activities. This paper presents alternative methodologies to support the optimization of civil protection assets in the occurrence of oil spill events and the results of their application on a section area of the Aveiro Lagoon, using an established geographic information system database containing crucial data. The presented methodologies are based on the Environmental Sensitivity Index developed by the North American National Oceanic and Atmospheric Administration (USA) and the Global Vulnerability Index which were applied on the Bay of Biscay (Spain). However, during the development of this work, neither of these methodologies was considered to entirely assess the study area in its full extent, which led to the need to adapt and define a bespoke approach. The introduced changes include extra categories in shoreline classification, an adapted physical vulnerability index for coastal lagoons, differentiated aspects for highly protected status areas, qualitative assessment of socioeconomic features and an access and operability index created to support emergency operation response. The resulting maps are the subject of analysis, in which considerations regarding control and cleanup methods are introduced, together with guidelines for further integration in local risk management strategies.

  14. Spatio-temporal variability and the impact of Phailin on water quality of Chilika lagoon

    NASA Astrophysics Data System (ADS)

    Barik, Saroja K.; Muduli, Pradipta R.; Mohanty, Bita; Behera, Alaya T.; Mallick, Suprava; Das, Abhijit; Samal, R. N.; Rastogi, Gurdeep; Pattnaik, Ajit K.

    2017-03-01

    Chilika, Asia's largest brackish water lagoon was studied for 4 years (2011-2015) to understand the variability of water quality and the impact of a very severe cyclone storm ;Phailin; (Category-5). During the study period environmental variables exhibited a significant variation among sectors, seasons, and years (p<0.05, n=1440). Correlation matrix showed the major source of phosphate in Chilika were from in situ processes whereas, nitrate and silicate were from the riverine influx. Principal component analysis revealed that the biological factor and riverine flux mostly controlled the water quality. The overall 'water quality Index' indicated that the ecological health of the Chilika lagoon was ;Good;. The Phailin had a notable impact on water quality as substantiated by the trends of several parameters. The decrease in nitrate and phosphate after Phailin was attributed to dilution by low nutrient freshwater flux from major rivers whereas, the significant increase in reactive silicate was attributed to mixing of silicate enriched fresh water. Post Phailin increase in dissolved oxygen and chlorophyll-a was attributed to wind-induced mixing and resuspension of benthic chlorophyll respectively. A substantial change of nutrient stoichiometry and decrease in photic depth after Phailin resulted a pull down of primary productivity in the Chilika lagoon.

  15. Benthic foraminifera of Puerto Rican mangrove-lagoon systems: Potential for paleoenvironmental interpretations

    SciTech Connect

    Culver, S.J. )

    1990-02-01

    Recent foraminiferal assemblages from four traverses across mangrove-lagoonal environments off Puerto Rico exhibit patterns of distribution that should be useful in paleoenvironmental interpretations. Variations in sediment substrate type, abundance and distribution of marine vegetation, and degree of exposure to wave and current activity appear to be important factors related to foraminiferal distributions and abundances. Cluster analysis of foraminiferal abundance data distinguishes four major assemblages. Other generally recognizable trends in foraminiferal assemblages include: offshore increase in species diversity; offshore increase in percent miliolids while percent rotaliids remain more or less constant; small peaks in percent textulariids immediately adjacent to mangrove growth; almost 100% agglutinated assemblages in fully mangrove environments; offshore increase in foraminiferal number except in areas of abundant Halimeda plate production where numbers of foraminifera are diluted; restriction of high abundances of Fissurina, Nonionella, Fursenkoina and Helenina to lagoons behind mangrove islands; restrictions of high abundances of Rosalina, Cibicides, Discorbis, Spiroloculina, Cyclogyra, Quinqueloculina, Amphistegina, Peneroplis and Archaias to lagoons seaward of mangrove islands. These trends provide a micropaleontological link between a potential petroleum source, mangrove swamps, and the potential petroleum reservoir, reef rocks.

  16. Hydromorphic to subaqueous soils transitions in the central Grado lagoon (Northern Adriatic Sea, Italy)

    NASA Astrophysics Data System (ADS)

    Vittori Antisari, Livia; De Nobili, Maria; Ferronato, Chiara; Natale, Marco; Pellegrini, Elisa; Vianello, Gilmo

    2016-05-01

    The Grado lagoon is among the largest in the Mediterranean sea and is characterized by salt marshes, where tides influenced the development of a complex micromorphology coupled to a micromosaic of vegetation covers. This study represents the first contribution to the understanding of the main processes governing formation, development and spatial transitions between hydromorphic and subaqueous soils in an Adriatic lagoon ecosystem. Physicochemical characteristics and development of soils were investigated in three salt marshes differing for their proximity to the open sea, textural composition and age of formation. Soils of back barrier salt marshes had A/C profiles and were mostly characterized by a sandy coarse texture that allows rapid drainage and subsurface oxygen exchanges. Soil sequences from the inner salt marsh to its submerged border slope or to a brackish waterhole do not simply represent a hydrosequence, but also reflect erosion/sorting/accumulation processes. The soils in the central part of the lagoon have finer texture and in displayed transition or cambic horizons. Silty clay loam textures and low positions allowed the development of more severe anoxic conditions and accumulation of sulphides. The tide oscillation strongly contributed to formation of redoximorphic features, intensity of anaerobic conditions but also colonization by different plant communities. Discriminant analysis was performed to identify physicochemical properties which discriminate the different soils according to geo-morphological position and prevailing plants. It confirmed that differentiation of plant communities occurred according to distinct morphological and physicochemical soil properties, but also acted as a primary affecting factor of pedogenesis.

  17. Dynamics of pollution-indicator and heterotrophic bacteria in sewage treatment lagoons.

    PubMed Central

    Legendre, P; Baleux, B; Troussellier, M

    1984-01-01

    The spatio-temporal dynamics of pollution-indicator bacteria and aerobic heterotrophic bacteria were studied in the sewage treatment lagoons of an urban wastewater center after 26 months of biweekly sampling at eight stations in these lagoons. Robust statistical methods of time-series analysis were used to study successional steps (through chronological clustering) and rhythmic behavior through time (through contingency periodogram). The aerobic heterotrophic bacterial community showed two types of temporal evolution: in the first four stations, it seems mainly controlled by the nutrient support capacity of the sewage input, whereas in the remaining part of the lagoon, it seems likely that the pollution-indicator bacteria are gradually replaced by other bacterial types that are better adapted to this environment. On the other hand, the pollution-indicator bacteria showed an annual cycle which increased in amplitude at distances further from the wastewater source. The main events in this cycle were produced simultaneously at all stations, indicating control of these bacterial populations by climatic factors, which act through physical and chemical factors, and also through other biological components of this ecosystem (phytoplankton and zooplankton). Finally, we use results from this study to suggest a modified design for a future study program. Images PMID:6497372

  18. Evaluation of Monensin Transport to Shallow Groundwater after Irrigation with Dairy