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TitleMarine geodiversity of northeastern Brazil: a step towards benthic habitat mapping in Pernambuco Continental Shelf
DownloadDownload (whole publication)
AuthorLucatelli, D; Camargo, J M R; Brown, C J; Souza-Filho, J F; Guedes-Silva, E; Araújo, T C M
SourceProgram and abstracts: 2017 GeoHab Conference, Dartmouth, Nova Scotia, Canada; by Todd, B J; Brown, C J; Lacharité, M; Gazzola, V; McCormack, E; Geological Survey of Canada, Open File 8295, 2017 p. 81, https://doi.org/10.4095/305889 (Open Access)
LinksGeoHab 2017
Year2017
PublisherNatural Resources Canada
Meeting2017 GeoHab: Marine Geological and Biological Habitat Mapping; Dartmouth, NS; CA; May 1-4, 2017
Documentopen file
Lang.English
Mediaon-line; digital
RelatedThis publication is contained in Todd, B J; Brown, C J; Lacharité, M; Gazzola, V; McCormack, E; (2017). Program and abstracts: 2017 GeoHab Conference, Dartmouth, Nova Scotia, Canada, Geological Survey of Canada, Open File 8295
File formatpdf
AreaPernambuco; Brazil
Lat/Long WENS -35.0000 -33.0000 -7.0000 -10.0000
Subjectsmarine geology; surficial geology/geomorphology; environmental geology; geophysics; mapping techniques; oceanography; marine environments; coastal studies; conservation; marine organisms; marine ecology; resource management; biological communities; environmental studies; ecosystems; continental margins; continental shelf; continental slope; benthos; marine sediments; seafloor topography; bedforms; textures; sedimentary structures; bathymetry; Northeastern Brazil Continental Shelf; geological mapping; geological mapping techniques; biology; habitat mapping; habitat conservation; habitat management; marine protected areas
ProgramOcean Management Geoscience, Offshore Geoscience
Released2017 09 26
AbstractThe Northeastern Brazil Continental Shelf (NEBCS) is one of the largest shelves off the Brazilian coast, and it is strongly influenced by volcanic and tectonic processes. It can be divided in three portions: Inner shelf (limited by 20 m isobaths), Mid-shelf (from 20 to 40 m depth), and Outer shelf (beyond 40 m depth). Pernambuco is one of the nine States from the Northeast region of Brazil, comprising a coast line of 187 Km (from 07°37.71'S to 08°54.34'S) and an average width of 33.28 Km. The littoral zone is strongly influenced by urban development, with extreme pollution in some areas, particularly near the capital Recife and the metropolitan region. Nevertheless, there are two Marine Protected Area (MPA) included in the Pernambuco EEZ, namely "Fernando de Noronha Archipelago" and "APA Costa dos Corais". However, there have been no habitat mapping studies within this region of the continental shelf, and only a small number along Brazilian coast. Based on the limited information available, the present work aimed to initiate the compilation of existing seafloor data sets on the Pernambuco region. The main objective was to map the physiography and relate it with the classes of sediment, providing a map of the geodiversity from the coast of Pernambuco (from inner to outer shelf).
To achieve the objectives of the study, abiotic data available in a public database, and results of technical-scientific surveys from the area were explored. Specifically, topography, slope, and sedimentary texture data were integrated. The topography was based on Gorini (1996). The map curvature was generated on ArcMap 10.1 software. Folks' classes were used to classify the sediment and stations were interpolated by natural neighbor. To improve the information for the locality, data from the Brazilian National Oceanographic Data Bank (BNDO) was added. Thus, a total of 314 samples were accomplished for the analyses. Multidimensional and PCA analyses were conducted using PRIMER 6.
Results of bathymetric analysis suggested some considerations: Inner and Outer shelf are narrow in the south and broaden northward along the shelf. On the other hand, the Mid-shelf is a broad southward and narrow at North portion. The slope is variable, being possible to observe several long portions with low degree (0.8-1°) of steepness along the Inner shelf. The presence of steps toward Mid-shelf could be observed as well. A flat portion is registered at the southern part of the shelf. Irregular areas are shown toward North. Pernambuco's platform presents its edge between 55-65 m, revealing an extended stability of the continental shelf, in terms of tectonic and sedimentary processes. The abrupt gradient variation of the shelf edge is clearly marked, as well as the strong steepness on superior slope. Additionally, the MDS and PCA analyses reflect the influence of terrigenous sediment, coming from continental region for the Inner shelf, and the presence of calcareous algae plus organogenic fragments (from beach-rocks and corals) on the mid and outer shelf. The sediment composition is highly relevant to the benthos distribution. Based on our results a texture map was constructed showing the general pattern for the sediment distribution along the shelf of Pernambuco.
GEOSCAN ID305889