Percorrer por autor "Amorim, Patrícia"
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- Analysis of size spectra off northwest Africa: a useful indicator in tropical areas?Publication . Stobberup, Kim A.; Inejih, C. A. O.; Traore, S.; Monteiro, C.; Amorim, Patrícia; Erzini, KarimChanges in the size spectra of demersal fish communities off Cape Verde (1988, 1994), Guinea (1985-1995), and Mauritania (1987-2001) were studied. Intercepts and slopes showed opposite trends for Guinea and Mauritania, but were relatively stable in spite of a strong increase in landings per unit area. For Cape Verde, there were marked changes in size structure, seemingly inconsistent with the more moderate fishing pressure there. Changes in size structure do not seem to be suitable indicators of the effects of fishing in areas characterized by faster growth rates, small sizes, high species diversity, and complex interrelationships, such as the tropics. (c) 2005 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.
- Broad-scale mapping of seafloor habitats in the north-east Atlantic using existing environmental dataPublication . Vasquez, Mickaël; Mata Chacón, D.; Tempera, Fernando; O'Keeffe, Eimear; Galparsoro, Ibon; Sanz Alonso, J. L.; Gonçalves, J. M. S.; Bentes, L.; Amorim, Patrícia; Henriques, Victor; McGrath, Fergal; Monteiro, Pedro; Mendes, Beatriz; Freitas, Rosa; Martins, Roberto; Populus, JacquesIf marine management policies and actions are to achieve long-term sustainable use and management of the marine environment and its resources, they need to be informed by data giving the spatial distribution of seafloor habitats over large areas. Broad-scale seafloor habitat mapping is an approachwhich has the benefit of producing maps covering large extents at a reasonable cost. This approach was first investigated by Roff et al. (2003), who, acknowledging that benthic communities are strongly influenced by the physical characteristics of the seafloor, proposed overlaying mapped physical variables using a geographic information system (GIS) to produce an integrated map of the physical characteristics of the seafloor. In Europe the method was adapted to the marine section of the EUNIS (European Nature Information System) classification of habitat types under the MESH project, andwas applied at an operational level in 2011 under the EUSeaMap project. The present study compiled GIS layers for fundamental physical parameters in the northeast Atlantic, including (i) bathymetry, (ii) substrate type, (iii) light penetration depth and (iv) exposure to near-seafloor currents andwave action. Based on analyses of biological occurrences, significant thresholds were fine-tuned for each of the abiotic layers and later used in multi-criteria raster algebra for the integration of the layers into a seafloor habitat map. The final result was a harmonised broad-scale seafloor habitat map with a 250 m pixel size covering four extensive areas, i.e. Ireland, the Bay of Biscay, the Iberian Peninsula and the Azores. The map provided the first comprehensive perception of habitat spatial distribution for the Iberian Peninsula and the Azores, and fed into the initiative for a pan- European map initiated by the EUSeaMap project for Baltic, North, Celtic and Mediterranean seas.