Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera Microfauna
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Anuário do Instituto de Geociências (Online) |
Texto Completo: | https://revistas.ufrj.br/index.php/aigeo/article/view/7820 |
Resumo: | The objective of this study was to evaluate the temporal distribution of the foraminifera microfauna of the Caravelas River estuary (Bahia) to determine the different stages of marine influence on this ecosystem. For this purpose, two core samples 60 cm in length were collected at different sites in the estuary. In the laboratory, subsamples were taken from the sediment columns every 2 cm. The samples were subjected to standard analysis for foraminifera. We collected, stored, and identified the first 100 samples to determine the fauna diversity. The data analysis involved calculation of relative abundances, occurrence frequencies, diversity indices, richness, dominance, and confinement. The integrated analysis of the richness and diversity indices for the TCV1A core indicated that the oscillations between the highest and lowest marine influences were not representative to the point of promoting marked events of enrichment and depletion of the fauna at this sampling site. In contrast, analysis of the TCV2A core showed a restricted marine influence during the deposition period of this sediment column, especially since the 1980s. This hypothesis can be confirmed by the richness and diversity values, which show signs of faunal impoverishment in different sections of this core. |
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Anuário do Instituto de Geociências (Online) |
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Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera MicrofaunaCaracterização do Estuário do Rio Caravelas (Bahia) a partir de Análises de Distribuição Temporal da Microfauna de ForaminíferosBahia; Caravelas River Estuary; Foraminifera; Confinement Index.Bahia; Estuário do Rio Caravelas; Foraminíferos; Índice de Confinamento.The objective of this study was to evaluate the temporal distribution of the foraminifera microfauna of the Caravelas River estuary (Bahia) to determine the different stages of marine influence on this ecosystem. For this purpose, two core samples 60 cm in length were collected at different sites in the estuary. In the laboratory, subsamples were taken from the sediment columns every 2 cm. The samples were subjected to standard analysis for foraminifera. We collected, stored, and identified the first 100 samples to determine the fauna diversity. The data analysis involved calculation of relative abundances, occurrence frequencies, diversity indices, richness, dominance, and confinement. The integrated analysis of the richness and diversity indices for the TCV1A core indicated that the oscillations between the highest and lowest marine influences were not representative to the point of promoting marked events of enrichment and depletion of the fauna at this sampling site. In contrast, analysis of the TCV2A core showed a restricted marine influence during the deposition period of this sediment column, especially since the 1980s. This hypothesis can be confirmed by the richness and diversity values, which show signs of faunal impoverishment in different sections of this core.O objetivo do presente estudo foi avaliar a distribuição temporal da microfauna de foraminíferos do estuário do Rio Caravelas (Bahia), para determinar diferentes estágios de influência marinha sobre este ecossistema. Foram analisadas amostras provenientes de dois testemunhos (TCV1A e TCV2A) de 60 cm de comprimento, coletados em pontos distintos do estuário. Em laboratório foram realizadas subamostragens a cada 2 cm, cujo sedimento foi submetido ao processo padrão para análise de framiníferos. De cada amostra foram triadas, armazenadas e identificadas as 100 primeiras testas de foraminíferos para determinação da diversidade da fauna. A análise dos dados envolveu o cálculo da abundância relativa, frequência de ocorrência, índices de diversidade, riqueza, dominância e confinamento. Considerando a análise integrada dos índices de riqueza e diversidade para o testemunho TCV1A, observou-se que as oscilações entre períodos de menor e maior influência marinha não foram representativas ao ponto de promoverem marcantes eventos de enriquecimento ou empobrecimento faunístico neste ponto de amostragem. Entretanto, a análise do testemunho TCV2A revelou, no seu ponto de amostragem, uma condição restrita de influência marinha ao logo do período de deposição desta coluna sedimentar, sobretudo a partir da década de 80. Essa hipótese pôde ser confirmada através dos valores de riqueza e diversidade, que mostram sinais de empobrecimento faunístico em diferentes trechos deste testemunho.Universidade Federal do Rio de Janeiro2017-02-15info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://revistas.ufrj.br/index.php/aigeo/article/view/782010.11137/2014_2_23_38Anuário do Instituto de Geociências; Vol 37, No 2 (2014); 23-38Anuário do Instituto de Geociências; Vol 37, No 2 (2014); 23-381982-39080101-9759reponame:Anuário do Instituto de Geociências (Online)instname:Universidade Federal do Rio de Janeiro (UFRJ)instacron:UFRJenghttps://revistas.ufrj.br/index.php/aigeo/article/view/7820/6301Copyright (c) 2014 Anuário do Instituto de Geociênciashttp://creativecommons.org/licenses/by/4.0info:eu-repo/semantics/openAccessMachado, Altair de JesusAraújo, Helisângela Acris Borges de2017-02-15T17:28:22Zoai:www.revistas.ufrj.br:article/7820Revistahttps://revistas.ufrj.br/index.php/aigeo/indexPUBhttps://revistas.ufrj.br/index.php/aigeo/oaianuario@igeo.ufrj.br||1982-39080101-9759opendoar:2017-02-15T17:28:22Anuário do Instituto de Geociências (Online) - Universidade Federal do Rio de Janeiro (UFRJ)false |
dc.title.none.fl_str_mv |
Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera Microfauna Caracterização do Estuário do Rio Caravelas (Bahia) a partir de Análises de Distribuição Temporal da Microfauna de Foraminíferos |
title |
Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera Microfauna |
spellingShingle |
Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera Microfauna Machado, Altair de Jesus Bahia; Caravelas River Estuary; Foraminifera; Confinement Index. Bahia; Estuário do Rio Caravelas; Foraminíferos; Índice de Confinamento. |
title_short |
Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera Microfauna |
title_full |
Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera Microfauna |
title_fullStr |
Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera Microfauna |
title_full_unstemmed |
Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera Microfauna |
title_sort |
Characterization of the Caravelas River Estuary (Bahia) from a Temporal Distributional Analysis of the Foraminifera Microfauna |
author |
Machado, Altair de Jesus |
author_facet |
Machado, Altair de Jesus Araújo, Helisângela Acris Borges de |
author_role |
author |
author2 |
Araújo, Helisângela Acris Borges de |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Machado, Altair de Jesus Araújo, Helisângela Acris Borges de |
dc.subject.por.fl_str_mv |
Bahia; Caravelas River Estuary; Foraminifera; Confinement Index. Bahia; Estuário do Rio Caravelas; Foraminíferos; Índice de Confinamento. |
topic |
Bahia; Caravelas River Estuary; Foraminifera; Confinement Index. Bahia; Estuário do Rio Caravelas; Foraminíferos; Índice de Confinamento. |
description |
The objective of this study was to evaluate the temporal distribution of the foraminifera microfauna of the Caravelas River estuary (Bahia) to determine the different stages of marine influence on this ecosystem. For this purpose, two core samples 60 cm in length were collected at different sites in the estuary. In the laboratory, subsamples were taken from the sediment columns every 2 cm. The samples were subjected to standard analysis for foraminifera. We collected, stored, and identified the first 100 samples to determine the fauna diversity. The data analysis involved calculation of relative abundances, occurrence frequencies, diversity indices, richness, dominance, and confinement. The integrated analysis of the richness and diversity indices for the TCV1A core indicated that the oscillations between the highest and lowest marine influences were not representative to the point of promoting marked events of enrichment and depletion of the fauna at this sampling site. In contrast, analysis of the TCV2A core showed a restricted marine influence during the deposition period of this sediment column, especially since the 1980s. This hypothesis can be confirmed by the richness and diversity values, which show signs of faunal impoverishment in different sections of this core. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-02-15 |
dc.type.none.fl_str_mv |
|
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://revistas.ufrj.br/index.php/aigeo/article/view/7820 10.11137/2014_2_23_38 |
url |
https://revistas.ufrj.br/index.php/aigeo/article/view/7820 |
identifier_str_mv |
10.11137/2014_2_23_38 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
https://revistas.ufrj.br/index.php/aigeo/article/view/7820/6301 |
dc.rights.driver.fl_str_mv |
Copyright (c) 2014 Anuário do Instituto de Geociências http://creativecommons.org/licenses/by/4.0 info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Copyright (c) 2014 Anuário do Instituto de Geociências http://creativecommons.org/licenses/by/4.0 |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal do Rio de Janeiro |
publisher.none.fl_str_mv |
Universidade Federal do Rio de Janeiro |
dc.source.none.fl_str_mv |
Anuário do Instituto de Geociências; Vol 37, No 2 (2014); 23-38 Anuário do Instituto de Geociências; Vol 37, No 2 (2014); 23-38 1982-3908 0101-9759 reponame:Anuário do Instituto de Geociências (Online) instname:Universidade Federal do Rio de Janeiro (UFRJ) instacron:UFRJ |
instname_str |
Universidade Federal do Rio de Janeiro (UFRJ) |
instacron_str |
UFRJ |
institution |
UFRJ |
reponame_str |
Anuário do Instituto de Geociências (Online) |
collection |
Anuário do Instituto de Geociências (Online) |
repository.name.fl_str_mv |
Anuário do Instituto de Geociências (Online) - Universidade Federal do Rio de Janeiro (UFRJ) |
repository.mail.fl_str_mv |
anuario@igeo.ufrj.br|| |
_version_ |
1797053545835397120 |