12 research outputs found

    Assessing legacy contaminants in sediments from marine protected areas of the central coast of São Paulo (Brazil)

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    The presence of legacy contaminants in sediments from three Marine Protected Areas (MPAs) of the coast of São Paulo State was evaluated. Four sampling surveys were conducted between 2013 and 2015 in 10 sites, distributed along the Laje de Santos Marine and Xixova-Japui State Parks (PEMLS and XJSP, respectively) and Central Coast Marine Protection Area (APAMLC). Samples were analyzed for sediment texture, total organic carbon, CaCO3, metals (Al, Fe, Hg, Cd, Co, Cr, Cu, Ni, Pb and Zn), aliphatic and polycyclic aromatic hydrocarbons (AH and PAH). Sediments were generally sandy (excepting muddy samples from APAMLC), with variable amounts of TOC, OM and CaCO3. Most of the sediments exhibited low to moderate concentrations of metals, except APAMLC. Low contamination of sediments by hydrocarbons was found but samples from XLSP and APAMLC exhibited the highest concentrations of biogenic AH and PAH from pyrogenic sources. In APAMLC and PEMLS, the levels of metals can be considered as background levels according to geochemical indices (Igeo and EF). In XJSP and especially in APAMLC data indicated poor sediment quality, probably due to the effect of anthropic activities.A contaminação dos sedimentos superficiais foi avaliada neste estudo em amostras de áreas marinhas protegidas (AMP) da costa central de São Paulo. Quatro campanhas de amostragem foram feitas entre 2013 e 2015 em 10 sítios localizados nos Parques Estaduais Marinho da Laje de Santos e Xixová-Japuí (PEMLS e PEXJ, respectivamente), e Área de Proteção Ambiental Litoral Centro (APAMLC). As amostras foram analisadas quanto granulometria, carbono orgânico total, CaCO3, metais (Al, Fe, Hg, Cd, Co, Cr, Cu, Ni, Pb e Zn) e hidrocarbonetos alifáticos(AHs) e policíclicos aromáticos (PAHs). Em geral os sedimentos foram arenosos (exceto aqueles de APAMLC, que foram lamosos) e com quantidades variáveis de COT, MO e CaCO3. A maioria das amostras apresentaram baixas concentrações de metais de acordo com índices geoquímicos (Igeo e fatores de enriquecimento - FE). Baixa contaminação por hidrocarbonetos foi encontrada e em APAMLC os sedimentos apresentaram as maiores concentrações de AHs de origem biogênica e PAHs de pirogênicos. Nos sedimentos de APAMLC e PEMLS, os níveis de metais podem ser considerados como valores de referência. Já em PEXJ, os dados indicaram baixa qualidade de sedimentos, possivelmente devido às fontes antrópicas

    Assessing the sediment quality of the Laje de Santos marine state park and other marine protected areas of the central coast of São Paulo (Brazil)

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    Este estudo analisou a qualidade dos sedimentos de três Áreas Marinhas Protegidas (AMP) situadas na porção central do litoral paulista (Parque Estadual Marinho da Laje de Santos - PEMLS; Parque Estadual Xixová-Japuí- PEXJ; Área de Proteção Ambiental Marinha do Litoral Centro - APAMLC). Quatro campanhas de coleta foram organizadas (Setembro/Outobro-2013; Janeiro-2014; Julho-2014; Janeiro-2015). Amostras de sedimento foram coletadas em 10 pontos ao longo das 3 AMP. As amostras foram analisadas para granulometria, carbono orgânico total, CaCO3, metais, hidrocarbonetos alifáticos e policíclico aromáticos, e toxicidade de sedimento integral e interface sedimento-água. Análise de Componentes Principais foi utilizada na integração dos dados. A maioria das amostras exibiu baixa contaminação, exceto a amostra de P2 (APAMLC) onde níveis moderados de contaminantes foram detectados. Sedimentos de P7 e P9 (PEMLS) eventualmente apresentaram sinais de hidrocarbonetos de petróleo. As demais amostras não apresentaram contaminação relevante, mas tiveram toxicidades variáveis, especialmente os sedimentos predominantemente bioclásticos. A PCA indicou forte contribuição das propriedades do sedimento, principalmente CaCO3 e amônia, na geração da toxicidade, indicando que fatores naturais e/ou antrópicos podem estar induzindo a toxicidade nas AMP estudadas.In this study, the quality of sediments from three Marine Protected Areas (MPAs) located on the coast of São Paulo (Laje de Santos Marine State Park - PEMLS; Xixova-Japui State Park - XJSP; and Central Coast Marine Protection Area - APAMLC) was assessed. Four sampling surveys were conducted (September/October 2013; January 2014; July 2014; January 2015). Sediment samples were collected at10 sites, distributed along the 3 MPAs. Samples were analyzed for sediment texture, total organic carbon, CaCO3, metals, aliphatic and polycyclic aromatic hydrocarbons, and for whole-sediment and sediment-water interface toxicities. Principal component analysis (PCA) was used to integrate data. Most of the sediments exhibited low concentrations of chemicals, with the exception of those from P2 (APAMLC) where moderate levels of contaminants were detected. Sediments from P7 and P9 (PEMLS) occasionally showed signs of petroleum hydrocarbons. The other sediments showed no relevant contamination but presented variable toxicity, especially those of bioclastic composition. The PCA indicated a contribution of the sediment properties to the toxicities, especially the CaCO3. In bioclastic sediments, toxicity might be due to physical causes by or any indirect factor such as the presence of ammonia. It was concluded that both natural and anthropic factors are causing toxicity in sediments from the MPAs studied

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Relations between the biomass of benthic foraminifera living and models of vertical flux of organic particles in the region of the Campos Basin - RJ

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    Este trabalho tem como meta investigar a relação entre o fluxo vertical de matéria orgânica particulada (MOP) e a biomassa de foraminíferos bentônicos vivos na região do talude da Bacia de Campos/RJ (400 a 3000m). O fluxo vertical de MOP para o assoalho oceânico foi inferido através de modelos que utilizam dados de sensoriamento remoto, como estimativas da concentração de clorofila a, valores de temperatura da superfície do mar e produtos derivados destes (i.e. produção primária e determinação de classes de tamanho do fitoplâncton), enquanto que a biomassa de foraminíferos bentônicos foi estimada através da técnica de biovolume. Os resultados indicam que as estimativas de fluxo se correlacionaram com os conteúdos de carbono orgânico total (COT) no sedimento, com a biomassa total de 19 espécies de foraminíferos bentônicos e com a biomassa, sendo que a distribuição de biomassa dessas espécies evidencia além da quantidade de MOP, a qualidade da MOP (labilidade). A distribuição dos valores de fluxo vertical e biomassa total de foraminíferos bentônicos estão atreladas às feições de mesoescala (meandros e vórtices de Cabo Frio e Cabo de São Tomé), que propiciam o aumento de produtividade primária e o crescimento do microplâncton, aumentando o fluxo vertical e consequentemente o suplemento alimentar para os foraminíferos bentônicos, estimulando o aumento de biomassa destes.This study aims to investigate the relationship between the particulate organic matter (POM) vertical flux and living benthic foraminifera biomass in the slope of Campos Basin region (between 400 and 3000). The POM vertical flux to the seafloor was inferred through models using remote sensing data, such as estimates of chlorophyll a concentration, sea surface temperature and derivatives of these (i.e. primary production and determination of classes phytoplankton size), whereas the biomass of benthic foraminifera was estimated using the biovolume technique . The fluxes estimates were correlated with total organic carbon (TOC) contents in the sediments, with benthic foraminifera total biomass and with 19 species biomass. The spatial distribution of these species biomass reveals both POM quantity and quality (i.e. lability). The distribution of the values of POM vertical flux and foraminifera total biomass are linked to mesoscale features (eddies and meanders in Cape Frio and Cape São Tomé), which provide increased primary productivity and microplankton growth increasing the POM vertical flux and consequently the food supplement for benthic foraminifera community, stimulating biomass increase

    Assessing legacy contaminants in sediments from marine protected areas of the central coast of São Paulo (Brazil)

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    Abstract The presence of legacy contaminants in sediments from three Marine Protected Areas (MPAs) of the coast of São Paulo State was evaluated. Four sampling surveys were conducted between 2013 and 2015 in 10 sites, distributed along the Laje de Santos Marine and Xixova-Japui State Parks (PEMLS and XJSP, respectively) and Central Coast Marine Protection Area (APAMLC). Samples were analyzed for sediment texture, total organic carbon, CaCO3, metals (Al, Fe, Hg, Cd, Co, Cr, Cu, Ni, Pb and Zn), aliphatic and polycyclic aromatic hydrocarbons (AH and PAH). Sediments were generally sandy (excepting muddy samples from APAMLC), with variable amounts of TOC, OM and CaCO3. Most of the sediments exhibited low to moderate concentrations of metals, except APAMLC. Low contamination of sediments by hydrocarbons was found but samples from XLSP and APAMLC exhibited the highest concentrations of biogenic AH and PAH from pyrogenic sources. In APAMLC and PEMLS, the levels of metals can be considered as background levels according to geochemical indices (Igeo and EF). In XJSP and especially in APAMLC data indicated poor sediment quality, probably due to the effect of anthropic activities

    ON THE INTERPLAY BETWEEN HYDRODYNAMICS, BOTTOM MORPHOLOGY, SEDIMENTARY PROCESSES AND BENTHIC FORAMINIFERA ASSEMBLAGES IN THE SÃO PAULO BIGHT (BRAZIL, SW ATLANTIC)

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    Surface sediment samples recovered in the Sao Paulo Bight (SW Atlantic) were collected between 45 to 1132 m water depths to characterize sedimentary processes based on a multiproxy approach. This study analysis benthic foraminifera and abiotic data, including granulometry, TOC and C/N values. Spatial and yearly distributions of ocean chlorophyll-a concentrations [Chl-a] evaluated from available SeaWiFS Chlorophyll Ocean Colour Images also were analyzed. On the basis of the non-metric Multidimensional Scaling analysis two regions with different characteristics were identified (1) Sao Sebastiao Island and (2) Grande Island. The C/N results indicate that in most of the studied stations the organic matter supplied to the sea bottom is provided essentially by oceanic productivity. Concentrations of chlorophyll-a and TOC are higher in Grande Island region than in the Sao Sebastiao Island sector. In the first region the benthic foraminifera assemblages are larger but less diversified than in Sao Sebastiao Island sector. The foraminifera assemblages of Grande Island region are dominated by Globocassidulina subglobosa and composed mostly by opportunist species related to episodic availability of food inputs related to the Cabo Frio upwelling system. The influence of this system seems to decrease in Sao Sebastiao Island sector. In the deeper slope stations of the Sao Sebastiao Island region, the presence of an arborescent community (Rhadammina spp. and Rhizammina spp.) and Nodulina dentaliniformis suggests that the sedimentary regime is relatively more stable and contain a higher amount of refractory organic than in Grande Island region for the similar range of depths

    Assessing the sediment quality of the Laje de Santos marine state park and other marine protected areas of the central coast of São Paulo (Brazil)

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    Abstract In this study, the quality of sediments from three Marine Protected Areas (MPAs) located on the coast of São Paulo (Laje de Santos Marine State Park - PEMLS; Xixova-Japui State Park - XJSP; and Central Coast Marine Protection Area - APAMLC) was assessed. Four sampling surveys were conducted (September/October 2013; January 2014; July 2014; January 2015). Sediment samples were collected at10 sites, distributed along the 3 MPAs. Samples were analyzed for sediment texture, total organic carbon, CaCO3, metals, aliphatic and polycyclic aromatic hydrocarbons, and for whole-sediment and sediment-water interface toxicities. Principal component analysis (PCA) was used to integrate data. Most of the sediments exhibited low concentrations of chemicals, with the exception of those from P2 (APAMLC) where moderate levels of contaminants were detected. Sediments from P7 and P9 (PEMLS) occasionally showed signs of petroleum hydrocarbons. The other sediments showed no relevant contamination but presented variable toxicity, especially those of bioclastic composition. The PCA indicated a contribution of the sediment properties to the toxicities, especially the CaCO3. In bioclastic sediments, toxicity might be due to physical causes by or any indirect factor such as the presence of ammonia. It was concluded that both natural and anthropic factors are causing toxicity in sediments from the MPAs studied

    Environmental controls on the distribution of living (stained) benthic foraminifera on the continental slope in the Campos Basin area (SW Atlantic)

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    Living (stained) benthic foraminifera from deep-sea stations in the Campos Basin, southeastern Brazilian continental margin, were investigated to understand their distribution patterns and ecology, as well as the oceanographic processes that control foraminiferal distribution. Sediments were collected from 1050 m to 1950 m of water depth during the austral winter of 2003, below the Intermediate Western Boundary Current (IWBC) and the Deep Water Boundary Current (DWBC). Based on statistical analysis, vertical flux of particulate organic matter and the grain size of sediment seem to be the main factors controlling the spatial distribution of benthic foraminifera. The middle slope (1050 m deep) is characterized by relatively high foraminiferal density and a predominance of phytodetritus-feeding foraminifera such as Epistominella exigua and Globocassidulina subglobosa. The occurrence of these species seems to reflect the Brazil Current System (BCS). The above-mentioned currents are associated with the relatively high vertical flux of particulate organic matter and the prevalence of sandy sediments, respectively. The lower slope (between 1350 and 1950 m of water depth) is marked by low foraminiferal density and assemblages composed of Bolivina spp. and Brizalina spp., with low particulate organic matter flux values, muddy sediments, and more refractory organic matter. The distribution of this group seems to be related to episodic fluxes of food particles to the seafloor, which are influenced by the BCS at the surface and are deposited under low deep current activity (DWBC)
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