title: Characterization of organic matter in sediment cores of the Todos os Santos Bay, Bahia, Brazil, by elemental analysis and 13C NMR.
abstract: The impact of human activity on the sediments of Todos os Santos Bay in Brazil was evaluated by elemental analysis and 13C Nuclear Magnetic Resonance (13C NMR). This article reports a study of six sediment cores collected at different depths and regions of Todos os Santos Bay. The elemental profiles of cores collected on the eastern side of Frades Island suggest an abrupt change in the sedimentation regime. Autoregressive Integrated Moving Average (ARIMA) analysis corroborates this result. The range of depths of the cores corresponds to about 50 years ago, coinciding with the implantation of major onshore industrial projects in the region. Principal Component Analysis of the 13C NMR spectra clearly differentiates sediment samples closer to the Subaé estuary, which have high contents of terrestrial organic matter, from those closer to a local oil refinery. The results presented in this article illustrate several important aspects of environmental impact of human activity on this bay.
authors.affiliation: Centro de Pesquisa em Geofísica e Geologia, Instituto de Física, Universidade Federal da Bahia, 40170-115 Salvador, BA, Brazil.
authors.forename: A B
authors.initials: AB
authors.lastname: Costa
authors.forename: E H
authors.initials: EH
authors.lastname: Novotny
authors.forename: A C
authors.initials: AC
authors.lastname: Bloise
authors.forename: E R
authors.initials: ER
authors.lastname: de Azevedo
authors.forename: T J
authors.initials: TJ
authors.lastname: Bonagamba
authors.forename: M R
authors.initials: MR
authors.lastname: Zucchi
authors.forename: V L C S
authors.initials: VL
authors.lastname: Santos
authors.forename: A E G
authors.initials: AE
authors.lastname: Azevedo
mesh_terms: D001938:Brazil; D002244:Carbon / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009584:Nitrogen / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis*; D012623:Seawater / Q000032:analysis / Q000737:chemistry; D013455:Sulfur / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D013455:Sulfur; D002244:Carbon; D009584:Nitrogen