title: Late Holocene evolution and increasing pollution in Guanabara Bay, Rio de Janeiro, SE Brazil.
abstract: To detect changes during the Late Holocene and historical periods in Guanabara Bay, the paleoecological and ecological parameters from nine cores were analysed using foraminiferal assemblages and bioindicators. Using radiocarbon dates and sedimentation rates in the cores, it was possible to detect the first Europeans' arrival in the 16th century. Foraminiferal bioindicators of organic matter and human pollution were correlated with radiocarbon dates from the bottom and middle of the cores in each region and revealed an increase in pollution along the cores. The foraminiferal results were compared with total organic carbon (TOC) values before, during and after European settlement and showed a historical increase in organic matter. Pristine mangrove ecosystems are characterised by agglutinated species such as Ammotium salsum, and the presence of this organism also confirmed the extent of historical mangrove forests. Ammonia tepida, Buliminella elegantissima and Elphidium excavatum were the dominant species, but they presented distinct patterns over time. B. elegantissima was dominant before the European influence in older sediments with high organic matter content that were found at deeper intervals. A. tepida is dominant in younger sediments at upper intervals, as a bioindicator of human pollution.
authors.affiliation: Depto de Geologia, IGEO, CCMN/Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 274, Cidade Universitária, 21941-916 Rio de Janeiro, RJ, Brazil. Electronic address: vilela@geologia.ufrj.br.
authors.forename: Claudia Gutterres
authors.initials: CG
authors.lastname: Vilela
authors.affiliation: Depto de Geologia, IGEO, CCMN/Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 274, Cidade Universitária, 21941-916 Rio de Janeiro, RJ, Brazil. Electronic address: bidaorioli@gmail.com.
authors.forename: Brígida Orioli
authors.initials: BO
authors.lastname: Figueira
authors.affiliation: Depto de Geologia, IGEO, CCMN/Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 274, Cidade Universitária, 21941-916 Rio de Janeiro, RJ, Brazil. Electronic address: ncardosomariana@yahoo.com.br.
authors.forename: Mariana Cardoso
authors.initials: MC
authors.lastname: Macedo
authors.affiliation: Instituto de Geociências, Lagemar/Universidade Federal Fluminense, Av. Litorânea s/n, Gragoatá, 24210-340 Niterói, RJ, Brazil. Electronic address: jabneto@id.uff.br.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Baptista Neto
mesh_terms: D061006:Bays / Q000737:chemistry; D005075:Biological Evolution; D001938:Brazil; D004784:Environmental Monitoring; D056908:Foraminifera / Q000737:chemistry / Q000254:growth & development*; D019015:Geologic Sediments / Q000737:chemistry; D012623:Seawater / Q000737:chemistry; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data*
keywords: Cores; Foraminiferal bioindicator; Pollution; Radiocarbon dates