Benthic Foraminifera and Bacterial Activity as a Proxy for Environmental Characterization in Potengi Estuary, Rio Grande do Norte, Brazil

The aim of this study was to identify possible zonation patterns and assess the environmental impact on the Potengi River Estuary, Rio Grande do Norte State, through the distribution of benthic foraminifera associated to bacterial activity and abiotic parameters. Six sediment samples were collected from locations that presented clear signs of pollution. The environment was predominantly anaerobic and fermentation occurred at all sites. Forty-two species of foraminifera were identified. The dominant species were Ammonia tepida and Arenoparrella mexicana, which are known to be opportunistic, and able to adapt to rapidly changing conditions. CCA analyses showed that salinity and organic matter, followed by bacterial carbon, were more strongly linked to organism distribution in the Potengi River Estuary. Dissolved oxygen concentration, temperature and total organic matter were higher at the estuary mouth than at the other sites, creating favorable conditions for foraminiferal growth and allowing the faunistic succession on the upper estuary. As foraminifera assemblages when associated to environmental parameters can be used as efficient proxies for environmental diagnosis, these results suggest that the Potengi Estuary is under great stress from the surrounding urban development

Foraminíferos bentônicos e atividade bacteriana como ferramenta para análise ambiental no Estuário do Rio Pontegi, Rio Grande do Norte, Brasil

The aim of this study was to identify possible zonation patterns and assess the environmental impact on the Potengi River Estuary, Rio Grande do Norte State, through the distribution of benthic foraminifera associated to bacterial activity and abiotic parameters. Six sediment samples were collected from locations that presented clear signs of pollution. The environment was predominantly anaerobic and fermentation occurred at all sites. Forty-two species of foraminifera were identified. The dominant species were Ammonia tepida and Arenoparrella mexicana, which are known to be opportunistic, and able to adapt to rapidly changing conditions. CCA analyses showed that salinity and organic matter, followed by bacterial carbon, were more strongly linked to organism distribution in the Potengi River Estuary. Dissolved oxygen concentration, temperature and total organic matter were higher at the estuary mouth than at the other sites, creating favorable conditions for foraminiferal growth and allowing the faunistic succession on the upper estuary. As foraminifera assemblages when associated to environmental parameters can be used as efficient proxies for environmental diagnosis, these results suggest that the Potengi Estuary is under great stress from the surrounding urban development.Este estudo teve como objetivo estabelecer um modelo de zonação e avaliar o impacto ambiental sofrido pelo estuário do rio Potengi, estado do Rio Grande do Norte, através da distribuição das assembléias de foraminíferos associados à atividade bacteriana e a parâmetros físico-químicos. Seis amostras de sedimento foram coletadas em regiões que apresentavam algum tipo poluição aparente. Predominaram os processos bacterianos anaeróbicos principalmente sulfatoredução no estuário. Foram identificadas quarenta e duas espécies de foraminíferos. As espécies dominantes foram Ammonia tepida e Arenoparrella mexicana, que são conhecidas como oportunistas, pois se adaptam com facilidade as variações ambientais. A análise em CCA mostrou que a salinidade e a matéria orgânica, seguidos pelo carbono bacteriano, conduziram a distribuição dos organismos no estuário. A concentração de oxigênio, temperatura e matéria orgânica total foram mais altas na foz do que em outras estações, criando condições favoráveis ao crescimento de foraminíferos e permitiu uma sucessão faunística em direção ao estuário superior. Assembléias de foraminíferos quando associadas a parâmetros ambientais podem ser usadas como eficientes indicadores para o diagnostico ambiental. Os resultados sugeriram que o estuário do rio Potengi encontra-se sobre condições de grande estresse ambiental provocado pelo desenvolvimento urbano a sua volta

Response of Benthic Foraminifera to organic matter quantity and quality and bioavailable concentrations of metals in Aveiro Lagoon (Portugal)

This work analyses the distribution of living benthic foraminiferal assemblages of surface sediments in different intertidal areas of Ria de Aveiro (Portugal), a polihaline and anthropized coastal lagoon. The relationships among foraminiferal assemblages in association with environmental parameters (temperature, salinity, Eh and pH), grain size, the quantity and quality of organic matter (enrichment in carbohydrates, proteins and lipids), pollution caused by metals, and mineralogical data are studied in an attempt to identify indicators of adaptability to environmental stress. In particular, concentrations of selected metals in the surficial sediment are investigated to assess environmental pollution levels that are further synthetically parameterised by the Pollution Load Index (PLI). The PLI variations allowed the identification of five main polluted areas. Concentrations of metals were also analysed in three extracted phases to evaluate their possible mobility, bioavailability and toxicity in the surficial sediment. Polluted sediment in the form of both organic matter and metals can be found in the most confined zones. Whereas enrichment in organic matter and related biopolymers causes an increase in foraminifera density, pollution by metals leads to a decline in foraminiferal abundance and diversity in those zones. The first situation may be justified by the existence of opportunistic species (with high reproduction rate) that can live in low oxic conditions. The second is explained by the sensitivity of some species to pressure caused by metals. The quality of the organic matter found in these places and the option of a different food source should also explain the tolerance of several species to pollution caused by metals, despite their low reproductive rate in the most polluted areas. In this study, species that are sensitive and tolerant to organic matter and metal enrichment are identified, as is the differential sensitivity/tolerance of some species to metals enrichment.CNPq [401803/2010-4]; [PEst-OE/CTE/UI4035/2014]info:eu-repo/semantics/publishedVersio

Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

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Distribution maps of foraminiferal density (FD, n.°/g), Shannon Index (H’) values and percentage of the specie: <i>A</i>. <i>tepida</i>, <i>H</i>. <i>germanica</i>, <i>E</i>. <i>excavatum</i>, <i>T</i>. <i>inflata</i>, <i>P</i>. <i>mediterranensis</i>, <i>E</i>. <i>margaritaceum</i> and <i>Q</i>. <i>seminula</i>.

<p>Legend: OvCh—Ovar Channel, SJCH—São Jacinto Channel, MuCh—Murtosa Channel, EsCh—Espinheiro Channel, MiCh—Mira Channel.</p

Total available concentrations (μg kg^-1) in the studied sites of toxic metals considered in this work.

<p>Legend: OvCh—Ovar Channel, MuCh—Murtosa Channel, EsCh—Espinheiro Channel, AvC—Aveiro city canals, AvH—Aveiro Harbor</p

Distribution maps of: Pollution Load Index (PLI) values, total organic carbon (TOC, %) content, total concentrations of biopolymers (TBP, mg/g) and concentrations of proteins (PTN, mg/g), carbohydrates (CHO, mg/g) and lipids (LIP, mg/g).

<p>Legend: OvCh—Ovar Channel, SJCH—São Jacinto Channel, MuCh—Murtosa Channel, EsCh—Espinheiro Channel, MiCh—Mira Channel.</p

Bioaccumulation of potentially toxic elements in Ammonia tepida (foraminifera) from a polluted coastal area

International audienceThis work documents the presence of potentially toxic elements (PTEs) in the sediment and in tests of Ammonia tepida, one of the most common benthic foraminifera species in coastal environments worldwide. It aims to analyze if the presence of PTEs in the carbonate test of this species is related to metals concentration in the sediment aiming its application in paleoenvironmental studies. Three chambers of fifty A. tepida specimens from contaminated and uncontaminated sediments from the Sepetiba Bay, one of the most polluted coastal systems from the SE Brazil, were analyzed using an Environmental Scanning Electron Microscope coupled with an X-ray Dispersive Energy Spectrometer. The results reveal the presence of lithogenic elements and PTEs in the tests of A. tepida. Relatively high values of Pb, Hg and Sn were found in specimens recovered from both polluted and unpolluted sediment layers. The bioaccumulation index revealed higher enrichment of Cd and Cr in tests from sediments moderately to heavily polluted by Cd and to a lesser extent by Cr. The results suggest that the incorporation of metals might be controlled and affected by several factors, such as the water residence time, availability of the metals, and biogeochemical processes. As a result, applications of this method utilizing A. tepida for paleoenvironmental studies do not appear to be feasible without further research

Available concentrations (μg kg^-1) in the studied sites of: a) Zn, b) Pb, c) As, d) Cu and e) Hg, in the three mobile phases (S1, S2 and S3).

<p>Legend: OvCh—Ovar Channel, MuCh—Murtosa Channel, EsCh—Espinheiro Channel, AvC—Aveiro city canals, AvH—Aveiro Harbor</p

Study area.

<p>The studied sites are labelled with numbers. Legend: OvCh—Ovar Channel, SJCH—São Jacinto Channel, MuCh—Murtosa Channel, EsCh—Espinheiro Channel, MiCh—Mira Channel.</p