57 research outputs found

    Search for bioindicators of pollution in the Guanabara Bay: integrations of ecologic patterns

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    Guanabara Bay, since its discovery, has largely changed with the human occupation causing large amounts of deposited sediment and waste, as well as domestic and industry sewage. Surface sediment was analysed for foraminifera and ostracoda distribution, diversity and dominance studies. These results were compared with TOC analyses aiming the determination of pollution bioindicators. In general, foraminifera dominant species were Ammonia tepida, Buliminella elegantissima and Quinqueloculina seminulum. The foraminifera assemblages presented distinct abundance and diversity values in different regions of the bay. The diversity was higher in the entrance (south) and in the central region than in the north region of the bay. The dominant species, that are characteristic of stressed environments, presented higher values of abundance in the north region. The TOC values increased from south to north regions, and were inversely proportional to foraminifera diversity. The very high TOC values in very polluted areas suggest sediment deposition in anoxic-dysoxic environment. The ostracoda Gen. Cyprideis was dominant and its occurrence increased from south to north region. Occurrence of Callistocythere sigmocostata, Xestoleberis sp., Aurila sp., and Paracypris sp. were restricted to the entrance and central area, indicating a preference for less restricted conditions, like marine conditions. Foraminifera and ostracoda characteristic responses to the environment conditions related high TOC values showed their importance as bioindicators of stressed environments caused by anthropogenic pollution, in the Guanabara Bay.A Baía de Guanabara, desde o seu descobrimento, tem sido bastante modificada pela ocupação humana, causando o acúmulo de grande quantidade de sedimento depositado e lixo, bem como lançamento de esgotos domésticos e industriais. Sedimentos superficiais foram analisados visando o estudo da distribuição, diversidade e dominância de foraminíferos e ostracodes. Estes estudos foram comparados com análises de COT objetivando a determinação de bioindicadores de poluição. Em geral as espécies dominantes de foraminíferos foram Ammonia tepida,Buliminella elegantissima and Quinqueloculina seminulum. As associações de foraminíferos apresentam distintos valores de abundância e diversidade em diferentes regiões da Baía. A diversidade foi mais elevada na entrada (sul) e na região central do que na região norte da Baía. As espécies dominantes, que são características de ambientes sob estresse, apresentaram valores altos de abundância na região norte. Os valores de COT aumentaram da região sul para o norte e foram inversamente proporcionais à diversidade de foraminíferos. O elevados valores de COT em áreas muito poluídas sugerem deposição sedimentar em ambiente anóxico-desóxico. O Gen. Cyprideis, de ostracode, foi dominante e sua ocorrência aumentou da região sul para o norte. A ocorrência de Callistocythere sigmocostata, Xestoleberis sp., Aurila sp. e Paracypris sp. foi estrita à entrada e região central, indicando uma preferência por condições menos restritas, como condições marinhas. As respostas características dos foraminíferos e ostracodes às condições ambientais relacionadas aos elevados valores de COT mostraram sua importância como bioindicadores de ambientes sob estresse causado por poluição antropogênica na Baía de Guanabara

    Pervasive gaps in Amazonian ecological research

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    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

    The influence of social disclosure on the relationship between Corporate Financial Performance and Corporate Social Performance*

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    Esta pesquisa tem como objetivo geral investigar o efeito moderador do disclosure do Corporate Social Performance (D-CSP) na relação entre Corporate Social Performance (CSP - Performance Social Corporativa) e Corporate Financial Performance (CFP - Performance Financeira Corporativa). Com base nesse objetivo, a pesquisa apresentou um modelo no qual o D-CSP atua como moderador em relação aos stakeholders primários (funcionários, comunidade e fornecedores). O D-CSP é um mecanismo pelo qual os diversos aspectos sociais envolvidos nas políticas, ações e atividades discricionárias identificados no gerenciamento para stakeholder podem ser avaliados. Para testar o modelo, utilizou-se uma amostra de 1.147 empresas pertencentes a 10 distintos setores e aos cinco continentes do planeta. Utilizaram-se dados da base Bloomberg de 2010 a 2014, totalizando 5.623 observações. A relação foi testada utilizando-se o modelo de regressão linear múltipla com dados em painel com efeitos fixos, recorrendo-se à correção de Newey-West erro padrão robusto. Para efetuar os testes, utilizaram-se três construtos: D-CSP, CSP e CFP. Empregou-se, como medida de CSP, a CSP dos stakeholders funcionários, fornecedores e comunidade. Como medida do D-CSP, aplicaram-se os scores de disclosure de CSP disponíveis na base de dados e, como medida da CFP, utilizou-se o retorno sobre ativo (ROA). Os testes realizados apontaram a existência do efeito moderador positivo do disclosure na relação entre CSP de stakeholders primários e CFP. Os resultados permitem inferir que, além de apresentar um CSP positivo em relação aos stakeholders primários, é necessário divulgar tais resultados, contribuindo para desempenhos financeiros superiores.This study’s general objective is to investigate the moderating effect of Corporate Social Performance Disclosure (D-CSP) on the relationship between Corporate Social Performance (CSP) and Corporate Financial Performance (CFP). Based on this objective, the study presented a model in which D-CSP acts as a moderator in relation to primary stakeholders (employees, community, and suppliers). D-CSP is a mechanism through which the various social aspects involved in discretionary policies, actions, and activities identified in the management for stakeholders process can be evaluated. A sample of 1,147 companies belonging to 10 different sectors and five continents was used to test the model. Data were collected from the Bloomberg database, totaling 5,735 observations, from 2010 to 2014. The relationship was tested using the multiple linear regression model involving panel data with fixed effects, and the Newey-West robust standard errors correction. Three constructs, D-CSP, CSP, and CFP, were used to perform the tests. As a CSP measure, the CSP of the employee, supplier, and community stakeholders was used. As a D-CSP measure, the CSP disclosure scores available from the database were used, and return on assets (ROA) was used as a CFP measure. The tests carried out indicated the existence of a positive moderating effect of disclosure on the relationship between the CSP of primary stakeholders and CFP. Besides presenting a positive CSP in relation to the primary stakeholders the results enable it to be inferred that these results need to be disclosed, thus contributing to higher corporate financial performance
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