A study of the circulation in Bay of Ilha Grande and Bay of Sepetiba: part I. a survey of the circulation based on experimental field data

Signorini, Sérgio R.

doi:10.1590/s0373-55241980000100004

Cited by 43 publications

(19 citation statements)

References 2 publications

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“…Looking for the velocity fields, it is observed the dominance of low velocities of currents in the major part of Bay of Ilha Grande, with averaged values of the order of 0.05 m/s and 0.1 m/s, respectively for neap and spring tides. The current velocities simulated by the model are in good agreement with data measured in the bay (Signorini, 1980). Concerning the differences between the two scenarios, it was chosen to work with patterns of average currents for tide cycles in neap and spring condition.…”

Section: Hydrodynamic Circulation Modelingmentioning

confidence: 89%

Advanced nuclear reactors and tritium impacts. Modeling the aquatic pathway

Lamego

Soares

Aguiar

et al. 2013

Progress in Nuclear Energy

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Section: Hydrodynamic Circulation Modelingmentioning

confidence: 89%

Advanced nuclear reactors and tritium impacts. Modeling the aquatic pathway

Lamego

Soares

Aguiar

et al. 2013

Progress in Nuclear Energy

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“…The mean tidal range of the region is 1.50 m and currents, with a maximum speed of approximately 1 m/s, mainly regulate the hydrodynamic conditions (Fragoso 1999). At its western end, the Sepetiba Bay is connected to Ilha Grande Bay by a narrow channel in which the main current direction is from west to east (Signorini 1980, Fragoso 1999. Cardoso et al (2012), studying 12 sandy beaches on five islands within Sepetiba Bay, showed that the species richness and total abundance markedly increase in the inner bay, where the wave action is minimal.…”

Section: Study Areamentioning

confidence: 99%

“…It has a Beach Index (McLachlan and Dorvlo 2005) of 2.28 and is classified as a dissipative sandy beach. The dominant south/southwestern winds (Signorini 1980, Fragoso 1999) and the orientation of the beach in relationship to the oceanic swells are responsible for the log-spiral shape of the beach (LeBlond 1979, Bremmer 1983. The beach has a sheltered area at the narrow end and a more exposed area at the open end, creating a defined physical gradient of morphodynamic characteristics and sediment texture.…”

Section: Study Areamentioning

confidence: 99%

Variability of macrofauna distribution along a dissipative log-spiral sandy beach in Rio de Janeiro, Southeastern Brazil

et al. 2017

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Summary: Log-spiral beaches display defined physical gradients alongshore. However, the majority of studies focus on the variability of a single population of macrofauna species. We aimed to investigate the variation in species distribution and in community structure along ten transects on a log-spiral beach. Principal component analysis indicated a clear physical gradient alongshore. Redundancy analysis showed that the sheltered end was related to smaller particle sizes, higher organic matter content and high densities of polychaetes. The exposed end was characterized by coarser sand, lower organic matter content and a high presence of crustaceans. Model selection indicated that the "best fit" to explain the variability in the number of individuals included grain size and beach slope. Variability of the polychaete Scolelepis squamata was best explained by grain size, slope and sediment sorting. The best model for the cirolanid Excirolana armata only included sediment sorting. The physical gradient in sediment texture and the beach slope explained more than one-third of the variability in community structure. The physical variables were also correlated with the distribution of the individual species. We showed that the physical gradient on log-spiral coasts may be an important driver of macrofauna variability, even at mesoscales and in dissipative conditions. Keywords: macrofauna assemblage; curved beaches; mesoscale; intertidal; morphodynamic; physical gradient.Variabilidad en la distributión de la macrofauna a lo largo de una playa disipativa arenosa en espiral en Rio de Janeiro, Sudeste de Brasil Resumen: Las playas en espiral muestran gradientes físicos definidos a lo largo de su recorrido. En este trabajo se investiga la relación entre la distribución en la estructura de comunidades de la macrofauna de una playa y sus gradientes físicos mediante el estudio de 10 transectos. El análisis de componentes principales reveló un claro gradiente físico a lo largo de la playa. El análisis de redundancia mostró que el extremo protegido se caracterizó con tamaños de grano menor, mayor contenido de materia orgánica y uma mayor densidad de anélidos poliquetos. El extremo expuesto se caracterizó por arena gruesa, bajo contenido de materia orgánica y una alta densidad de crustáceos. El mejor ajuste para explicar el número de individuos en una muestra se relacionó con el tamaño del grano de arena y la pendiente de la playa. La variabilidad del poliqueto Scolelepis squamata se explicó mejor en base al tamaño de grano, la pendiente y la selección de su sedimento. Por su parte, el mejor modelo para explicar la variabilidad del cirolánido Excirolana armata solo incluyó la selección del sedimento. El gradiente físico en la textura del sedimento y la pendiente de la playa explicó más de la tercera parte de la variabilidad en la estructura comunitaria. A su vez, las variables físicas también se correlacionaron con la distribución de especies individuales de la macrofauna. El gradiente físico en las playas en espiral puede explica...

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“…However, during strong NE 70° winds this clockwise pattern is inverted, and most of the fluvial sediments are transported to the coast between Madeira Island and Itacuruçá (Figure 1), lowering surface salinities to about 20. 35 Mercury is an ubiquitous contaminant of urban and industrial effluents reaching Sepetiba Bay. Hg emissions to soils, waters and the atmosphere in Sepetiba Bay basin are mostly from diffuse sources, particularly from leaching of a large landfill, an oil-fired electric power plant, steel and iron production and waste incineration.…”

Section: Site Descriptionmentioning

confidence: 99%

Mercury speciation changes in waters of the sepetiba Bay, SE Brazil during tidal events and different seasons

Paraquetti¹,

Lacerda²,

Almeida³

et al. 2007

J. Braz. Chem. Soc.

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Este estudo descreve as mudanças na especiação de Hg nas águas da Baía de Sepetiba, SE, Brasil, ao longo do gradiente estuarino, durante eventos de maré em diferentes estações. A avaliação química das águas da baía indicou uma exportação de material particulado em suspensão (MPS) pobre em carbono orgânico para a plataforma continental adjacente, principalmente durante a estação chuvosa e uma importação de MPS oceânico rico em carbono orgânico, provavelmente de origem fitoplanctônica, durante a estação seca. A especiação química do Hg demonstrou que a produção de Hg 0 na Baía de Sepetiba pode ser controlada pela produtividade primária, e que a baía atua como produtora e exportadora de formas orgânicas de Hg para as áreas adjacentes, já que as maiores concentrações de Hg não-reativo foram encontradas durante a maré vazante. Não foram observadas correlações significantes entre as concentrações de Hg não-reativo e carbono orgânico dissolvido ou particulado. Em geral, as frações de Hg particulado, Hg não-reativo e Hg reativo representam 55%, 35% e 9,5% do conteúdo total de Hg nas águas da Baía de Sepetiba, respectivamente.This work describes changes in Hg speciation in water along the transport from Sepetiba Bay, SE Brazil, to the adjacent continental platform during tide events and in different seasons. The chemical evaluation of Sepetiba Bay waters showed that the bay exports suspended particulate material (SPM) impoverish in organic carbon to adjacent continental platform areas, mainly during the wet season and imports SPM enriched in organic carbon from the ocean, probably of phytoplanktonic origin, during the dry season. The chemical speciation of Hg during the study period showed that Hg 0 production can be controlled by primary productivity and that the bay acts as a producer and exporter of organic species of Hg to adjacent areas, since the highest non-reactive Hg concentrations were observed during the ebb tide. No significant correlations were found between non-reactive Hg and dissolved or particulate organic matter concentrations. In general the particulate Hg, non-reactive Hg and reactive Hg fractions represents 55%, 35.5% and 9.5% of the total Hg content in Sepetiba Bay waters, respectively.Keywords: mercury speciation, coastal area, organic carbon, Sepetiba Bay IntroductionCoastal environments are complex and very dynamic systems showing a strong salinity gradient, high variation of suspended matter concentration and complex hydrodynamic processes. They act as links between the terrestrial and oceanic environments, present a large capacity to accumulate materials of continental and marine origin and are strongly affected by tidal events and continental hydrology. These environments are also characterized by land-sea gradients of physicochemical processes such as oxidation/reduction, sorption/desorption and precipitation/dissolution, which result in gradients of dissolved chemical species concentration, ionic force, pH and redox potential, which are responsible for the precipitation of the major part of ...

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A study of the circulation in Bay of Ilha Grande and Bay of Sepetiba: part I. a survey of the circulation based on experimental field data

Cited by 43 publications

References 2 publications

Advanced nuclear reactors and tritium impacts. Modeling the aquatic pathway

Advanced nuclear reactors and tritium impacts. Modeling the aquatic pathway

Variability of macrofauna distribution along a dissipative log-spiral sandy beach in Rio de Janeiro, Southeastern Brazil

Mercury speciation changes in waters of the sepetiba Bay, SE Brazil during tidal events and different seasons

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