Vanessa Laut - Academia.edu (original) (raw)
Papers by Vanessa Laut
PLOS ONE, 2017
Vermelha Lagoon is a hypersaline shallow transitional ecosystem in the state of Rio de Janeiro (B... more Vermelha Lagoon is a hypersaline shallow transitional ecosystem in the state of Rio de Janeiro (Brazil). This lagoon is located in the protected area of Massambaba, between the cities of Araruama and Saquarema (Brazil), and displays two quite uncommon particularities: it exhibits carbonate sedimentation and displays the development of Holocene stromatolites. Due to both particularities, the salt industry and property speculation have been, increasingly, generating anthropic pressures on this ecosystem. This study aims to apply a multiproxy approach to evaluate the trophic state of Vermelha Lagoon based on physicochemical parameters and geochemical data for the quantification and qualification of organic matter (OM), namely total organic carbon (TOC), total sulfur (TS), total phosphorus (TP) and biopolymeric carbon (BPC), including carbohydrates (CHO), lipids (LIP) and proteins (PTN). The CHO/TOC ratio values suggest that OM supplied to the sediment is of autochthonous origin and results, essentially, from microbial activity. The cluster analyses allowed the identification of four regions in Vermelha Lagoon. The Region I included stations located in shallow areas of the eastern sector of Vermelha lagoon affected by the impact of the artificial channel of connection with Araruama Lagoon. The Region II, under the influence of salt pans, is characterized by the highest values of BPC, namely CHO promoted by microbiological activity. The Region III include stations spread through the lagoon with high values of dissolved oxygen and lower values of TP. Stromatolites and microbial mattes growth was observed in some stations of this sector. Region IV, where the highest values of TOC and TS were found, represents depocenters of organic matter, located in general in depressed areas. Results of this work evidences that the Vermelha Lagoon is an eutrophic
The objective of this work is to study heavy metal contamination in Ria de Aveiro, a lagoon syste... more The objective of this work is to study heavy metal contamination in Ria de Aveiro, a lagoon system located in the NW coast of Portugal. We analyzed 116 samples of bottom sediments collected along the main channels of the Ria de Aveiro. The sediments were subjected to grain-size, geochemical and mineralogical analyses. Furthermore, some environmental parameters were measured in water and sediment at each site. The elemental concentrations (analysed by ICP-MS) were assessed by total digestion of the sediments (with four acids) and by sequential chemical extraction for the Hg. This research highlighted that hydrodynamism controls the grain size and the composition of sediments. As consequence, in areas where the currents activity is low, fine sediments enriched in organic matter and phyllosilicates are deposited and many chemical elements are retained. The enrichment factor (EF) of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn and the pollution load index (PLI) allowed the identification of “hot spots” of contamination in this system. These are located mainly in the inner zone of Murtosa Channel, the Port of Salreu, at the northern end of the Ovar Channel, the canals of Aveiro town, in Espinheiro Channel and also in harbor areas located near the mouth of the lagoon. This enrichment is associated to anthropogenic activity around the lagoon and is introduced essentially through the contribution of rivers and water courses. The comparison of our data with the established Sediment Quality Guidelines (SQGs), developed by the NOAA, U.S., for evaluating the quality of the sediment allowed the identification of locals where concentrations of metals may have toxic effects on benthic organisms. This is the case for example of the internal zone of the Murtosa Channel, namely Laranjo Bay and adjacent small channels, in which the levels of contaminants (Zn, Pb, As, Hg, Cu, Cd and Ni) can cause toxic effects on living organisms with the possibility of bioaccumulation and biomagnification through food chains including man, with risks of public health.
Continental Shelf Research
Abstract Scarce knowledge is available concerning the diatom ecology of hypersaline environments ... more Abstract Scarce knowledge is available concerning the diatom ecology of hypersaline environments and their potential to use as bioindicators. The aim of this study was to characterize and quantify diatom assemblages from Vermelha Lagoon associated with environmental parameters in order to establish environmental quality bioindicators for hypersaline environments. Species distribution displayed a weak relationship with environmental parameters analyzed in DCA analyses. The cluster analyses evidenced the presence of four diatom groups in the lagoon: Group I - located on the south margin of the lagoon, represented by N. arenaria; Group II - located in the north, the central sector and near the communication channel with Araruama Lagoon, dominated by F. interposita. The Group III - distributed in the shallowest regions, where primary productivity is high. Species H. acutiuscula and C. placentula in this group reached high relative abundance values. Group IV is characterized by increased salinity and lipids values, characterizing hypertrophic sediment conditions. These stations were located in the Saltpan water catchment and were characterized by a decreased number of species and the dominance of A. robusta.
In September 2010 five sediment samples were collected along the estuary of the Arade River aimed... more In September 2010 five sediment samples were collected along the estuary of the Arade River aimed to identify environmental
compartments based on the distribution of foraminifera species and their relationship with physic-chemical, sedimentological and
geochemistry parameters. In the estuary were identified 39 foraminifera species, from wich 31 were calcareous species and 8
agglutinated species that which showed the great species richness values in Arade Estuary. The dominant species were Ammonia
tepida and Haynesina germanica that were identified in all sample stations. The mouth of estuary showed the highest values
of richness of specimens (31) and diversity (2.73) that demonstrated the strong marine influence in this region. Applying DAC
multivariate analysis was possible to identify three areas in the estuary: Section A - region of greater marine influence that has a
high concentration of inorganic carbon, sandy sediment and a large number of exotic species transported from adjacent platform
(Cibicides bertheloti, Asterigerinata mammila, Bolivina ordinaria and Bolivina elongata); Sector B - middle region of the estuary
with muddy sediment, high organic carbon and consists of species typical of estuaries. Sector C - more confined region of the
estuary, with muddy sediment, higher concentration of organic carbon in relation to sector B, which is represented by species of
agglutinated foraminifera and Ammonia parkinsoniana.
Keywords: Foraminifera; mesotidal estuary; estuarine compartments
The objective of this work is to study heavy metal contamination in Ria de Aveiro, a lagoon syste... more The objective of this work is to study heavy metal contamination in Ria de Aveiro, a lagoon system located in the NW coast of Portugal. We analyzed 116 samples of bottom sediments collected along the main channels of the Ria de Aveiro. The sediments were subjected to grain-size, geochemical and mineralogical analyses. Furthermore, some environmental parameters were measured in water and sediment at each site.
The elemental concentrations (analysed by ICP-MS) were assessed by total digestion of the sediments (with four acids) and by sequential chemical extraction for the Hg.
This research highlighted that hydrodynamism controls the grain size and the composition of sediments. As consequence, in areas where the currents activity is low, fine sediments enriched in organic matter and phyllosilicates are deposited and many chemical elements are retained.
The enrichment factor (EF) of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn and the pollution load index (PLI) allowed the identification of “hot spots” of contamination in this system. These are located mainly in the inner zone of Murtosa Channel, the Port of Salreu, at the northern end of the Ovar Channel, the canals of Aveiro town, in Espinheiro Channel and also in harbor areas located near the mouth of the lagoon. This enrichment is associated to anthropogenic activity around the lagoon and is introduced essentially through the contribution of rivers and water courses. The comparison of our data with the established Sediment Quality Guidelines (SQGs), developed by the NOAA, U.S., for evaluating the quality of the sediment allowed the identification of locals where concentrations of metals may have toxic effects on benthic organisms. This is the case for example of the internal zone of the Murtosa Channel, namely Laranjo Bay and adjacent small channels, in which the levels of contaminants (Zn, Pb, As, Hg, Cu, Cd and Ni) can cause toxic effects on living organisms with the possibility of bioaccumulation and biomagnification through food chains including man, with risks of public health.
PLOS ONE, 2017
Vermelha Lagoon is a hypersaline shallow transitional ecosystem in the state of Rio de Janeiro (B... more Vermelha Lagoon is a hypersaline shallow transitional ecosystem in the state of Rio de Janeiro (Brazil). This lagoon is located in the protected area of Massambaba, between the cities of Araruama and Saquarema (Brazil), and displays two quite uncommon particularities: it exhibits carbonate sedimentation and displays the development of Holocene stromatolites. Due to both particularities, the salt industry and property speculation have been, increasingly, generating anthropic pressures on this ecosystem. This study aims to apply a multiproxy approach to evaluate the trophic state of Vermelha Lagoon based on physicochemical parameters and geochemical data for the quantification and qualification of organic matter (OM), namely total organic carbon (TOC), total sulfur (TS), total phosphorus (TP) and biopolymeric carbon (BPC), including carbohydrates (CHO), lipids (LIP) and proteins (PTN). The CHO/TOC ratio values suggest that OM supplied to the sediment is of autochthonous origin and results, essentially, from microbial activity. The cluster analyses allowed the identification of four regions in Vermelha Lagoon. The Region I included stations located in shallow areas of the eastern sector of Vermelha lagoon affected by the impact of the artificial channel of connection with Araruama Lagoon. The Region II, under the influence of salt pans, is characterized by the highest values of BPC, namely CHO promoted by microbiological activity. The Region III include stations spread through the lagoon with high values of dissolved oxygen and lower values of TP. Stromatolites and microbial mattes growth was observed in some stations of this sector. Region IV, where the highest values of TOC and TS were found, represents depocenters of organic matter, located in general in depressed areas. Results of this work evidences that the Vermelha Lagoon is an eutrophic
The objective of this work is to study heavy metal contamination in Ria de Aveiro, a lagoon syste... more The objective of this work is to study heavy metal contamination in Ria de Aveiro, a lagoon system located in the NW coast of Portugal. We analyzed 116 samples of bottom sediments collected along the main channels of the Ria de Aveiro. The sediments were subjected to grain-size, geochemical and mineralogical analyses. Furthermore, some environmental parameters were measured in water and sediment at each site. The elemental concentrations (analysed by ICP-MS) were assessed by total digestion of the sediments (with four acids) and by sequential chemical extraction for the Hg. This research highlighted that hydrodynamism controls the grain size and the composition of sediments. As consequence, in areas where the currents activity is low, fine sediments enriched in organic matter and phyllosilicates are deposited and many chemical elements are retained. The enrichment factor (EF) of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn and the pollution load index (PLI) allowed the identification of “hot spots” of contamination in this system. These are located mainly in the inner zone of Murtosa Channel, the Port of Salreu, at the northern end of the Ovar Channel, the canals of Aveiro town, in Espinheiro Channel and also in harbor areas located near the mouth of the lagoon. This enrichment is associated to anthropogenic activity around the lagoon and is introduced essentially through the contribution of rivers and water courses. The comparison of our data with the established Sediment Quality Guidelines (SQGs), developed by the NOAA, U.S., for evaluating the quality of the sediment allowed the identification of locals where concentrations of metals may have toxic effects on benthic organisms. This is the case for example of the internal zone of the Murtosa Channel, namely Laranjo Bay and adjacent small channels, in which the levels of contaminants (Zn, Pb, As, Hg, Cu, Cd and Ni) can cause toxic effects on living organisms with the possibility of bioaccumulation and biomagnification through food chains including man, with risks of public health.
Continental Shelf Research
Abstract Scarce knowledge is available concerning the diatom ecology of hypersaline environments ... more Abstract Scarce knowledge is available concerning the diatom ecology of hypersaline environments and their potential to use as bioindicators. The aim of this study was to characterize and quantify diatom assemblages from Vermelha Lagoon associated with environmental parameters in order to establish environmental quality bioindicators for hypersaline environments. Species distribution displayed a weak relationship with environmental parameters analyzed in DCA analyses. The cluster analyses evidenced the presence of four diatom groups in the lagoon: Group I - located on the south margin of the lagoon, represented by N. arenaria; Group II - located in the north, the central sector and near the communication channel with Araruama Lagoon, dominated by F. interposita. The Group III - distributed in the shallowest regions, where primary productivity is high. Species H. acutiuscula and C. placentula in this group reached high relative abundance values. Group IV is characterized by increased salinity and lipids values, characterizing hypertrophic sediment conditions. These stations were located in the Saltpan water catchment and were characterized by a decreased number of species and the dominance of A. robusta.
In September 2010 five sediment samples were collected along the estuary of the Arade River aimed... more In September 2010 five sediment samples were collected along the estuary of the Arade River aimed to identify environmental
compartments based on the distribution of foraminifera species and their relationship with physic-chemical, sedimentological and
geochemistry parameters. In the estuary were identified 39 foraminifera species, from wich 31 were calcareous species and 8
agglutinated species that which showed the great species richness values in Arade Estuary. The dominant species were Ammonia
tepida and Haynesina germanica that were identified in all sample stations. The mouth of estuary showed the highest values
of richness of specimens (31) and diversity (2.73) that demonstrated the strong marine influence in this region. Applying DAC
multivariate analysis was possible to identify three areas in the estuary: Section A - region of greater marine influence that has a
high concentration of inorganic carbon, sandy sediment and a large number of exotic species transported from adjacent platform
(Cibicides bertheloti, Asterigerinata mammila, Bolivina ordinaria and Bolivina elongata); Sector B - middle region of the estuary
with muddy sediment, high organic carbon and consists of species typical of estuaries. Sector C - more confined region of the
estuary, with muddy sediment, higher concentration of organic carbon in relation to sector B, which is represented by species of
agglutinated foraminifera and Ammonia parkinsoniana.
Keywords: Foraminifera; mesotidal estuary; estuarine compartments
The objective of this work is to study heavy metal contamination in Ria de Aveiro, a lagoon syste... more The objective of this work is to study heavy metal contamination in Ria de Aveiro, a lagoon system located in the NW coast of Portugal. We analyzed 116 samples of bottom sediments collected along the main channels of the Ria de Aveiro. The sediments were subjected to grain-size, geochemical and mineralogical analyses. Furthermore, some environmental parameters were measured in water and sediment at each site.
The elemental concentrations (analysed by ICP-MS) were assessed by total digestion of the sediments (with four acids) and by sequential chemical extraction for the Hg.
This research highlighted that hydrodynamism controls the grain size and the composition of sediments. As consequence, in areas where the currents activity is low, fine sediments enriched in organic matter and phyllosilicates are deposited and many chemical elements are retained.
The enrichment factor (EF) of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn and the pollution load index (PLI) allowed the identification of “hot spots” of contamination in this system. These are located mainly in the inner zone of Murtosa Channel, the Port of Salreu, at the northern end of the Ovar Channel, the canals of Aveiro town, in Espinheiro Channel and also in harbor areas located near the mouth of the lagoon. This enrichment is associated to anthropogenic activity around the lagoon and is introduced essentially through the contribution of rivers and water courses. The comparison of our data with the established Sediment Quality Guidelines (SQGs), developed by the NOAA, U.S., for evaluating the quality of the sediment allowed the identification of locals where concentrations of metals may have toxic effects on benthic organisms. This is the case for example of the internal zone of the Murtosa Channel, namely Laranjo Bay and adjacent small channels, in which the levels of contaminants (Zn, Pb, As, Hg, Cu, Cd and Ni) can cause toxic effects on living organisms with the possibility of bioaccumulation and biomagnification through food chains including man, with risks of public health.