SIMILARITY BETWEEN THE DEAD AND LIVING FORAMINIFERAL ASSEMBLAGES OF THE NE SECTOR OF GUANABARA BAY (BRAZIL)

• Main Authors: MARIA VIRGÍNIA ALVES MARTINS, ABILIO SOARES-GOMES, CINTIA YAMASHITA, ANITA FERNANDES SOUZA PINTO, FABRIZIO FRONTALINI, CRISTINA SEQUEIRA, LAZARO LUIZ MATTOS LAUT, PIERRE BELART, NOUREDDINE ZAABOUB, PAULO MIRANDA, SILVIA HELENA DE MELLO E SOUSA, RUBENS FIGUEIRA, ASSANE LUIS PENA, DENISE LARA TERROSO, FERNANDO ROCHA
• Format: Article
• Language: English
• Published: Universidade do Estado do Rio de Janeiro 2016-12-01
• Series: Journal of Sedimentary Environments
• Subjects: living and dead foraminifera; different sediment fractions; taphonomic effects; environmental assessment; coastal system; guanabara bay
• Online Access: https://www.e-publicacoes.uerj.br/index.php/jse/article/view/26875/0
• ISSN: 2447-9462; 2447-9462

Guanabara Bay (GB), located at the coast of Rio de Janeiro State (Brazil), is an ecosystem rich in biodiversity both in terms of mega, macro and microfauna. However, the factors that control their distribution are still poorly understood. This work intends to identify the possible factors affecting the distribution of benthic foraminifera in the bay by comparing living and dead assemblages in selected sediment fractions. Substantial differences in terms of density, diversity and equitability of the species in the living and dead assemblages and in different sediment fractions (63-150 μm, 150-250 μm, 250-500 μm) are identified. Lower similarity (<70%) between the living and dead assemblages are associated with areas impacted by organic matter and may be mainly ascribed to either loss of tests due to dissolution, currents remobilization and abrasion, or inclusion of allochthonous species transported by currents. This work suggests that the use of the living plus dead assemblages or dead assemblages can reduce the accuracy of the results if the work intends to evaluate the environmental conditions.