Ciclos isotópicos e taxa de crescimento em Mussismilia hispida (verrill, 1902): um registro para o Atlântico Sul

• Ano de defesa: 2019
• Autor(a) principal: Silva, Isabel Cristina Bezerra Sandes
• Orientador(a): Campos, Alexandre Liparini
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Geociências e Análise de Bacias
• Palavras-chave em Português: Geociências; Geoquímica isotópica; Paleonclimatologia; Corais; Biologia dos recifes de coral; Atol das Rocas (Brasil); Taxa de crescimento; Corais hermatípicos
• Palavras-chave em Inglês: Extension rate; Isotopic geochemistry; Hermatypics corals
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS
• Link de acesso: http://ri.ufs.br/jspui/handle/riufs/11641

Skeleton of scleratinian corals incorporates geochemical data capable of accurately recording environmental changes, enabling climatic reconstruction of the tropical oceans history, aiding in understanding current global climate change. Such geochemical signatures (e.g. carbon isotope (δ13C) and oxygen (δ18O) can reveal information about the sea surface temperature (SST), salinity, cloud cover, among others. The Tropical South Atlantic, still has a lack of paleoclimatic studies using files based on corals. This research aims to estimate the growth rate and to investigate the changes of the δ13C and δ18O incorporated in the coral skeleton Mussismilia hispida during its growth, in the Atol das Rocas region, besides verifying the potential of using this data as a proxy in environmental variations studies. For this, three M. hispida colonies (MH1, MH2 and MH3) were used, in which samples were taken every 5mm with a dental drill, the extracted carbonate was stored and analyzed in the Stable Isotopes Laboratory of the Federal University of Pernambuco by mass spectrometry determining the values of δ13C and δ18O. The averages obtained for δ13C were (0.91‰, 0.40‰ and 0.57‰) and δ18O (-3.29‰, -4.09‰ and -4.27‰), for colonies 13MH1, 13MH2 and 13MH3 respectively. Furthermore, the average growth rates (mm/cycle) and the number of cycles were estimated for: 13MH1 2.83 ±0.51; 13MH2 3.21±0.86; and 13MH3 3.71±0.82. From the point of view of the use of coral as a climatic file, the species has a sufficient growth rate to obtain high resolution information. In order to consolidate this species as a reliable natural file it is necessary to expand the investigations carried out here for other regions of the Brazilian Northeast.