Influence of the Nazaré Canyon, central Portuguese margin, on late winter coccolithophore assemblages

Spatial and temporal variability in coccolithophore abundance and distribution in the NW Iberian coastal upwelling system

“…8). These results are in good agreement with previous works in the study area (Silva et al, 2008(Silva et al, , 2009Guerreiro et al, 2014), where C. leptoporus is regarded as a tracer of nutrientdepleted water masses of subtropical origin in the study area, suggesting a strong regional hydrographic control on its distribution. This paper reports on the assessment of the temporal and spatial variability and distribution of coccolithophore and coccolith abundances in the NW Iberian coastal upwelling system.…”

“…7), in agreement with Beaufort and Heussner (2001). In spite of previous work (Guerreiro et al, 2015) suggesting that its imprint in the underlying sediments may be under-represented owing to selective dissolution of delicate coccoliths, several studies propose that this genus can dominate the water column assemblage in the study area in occasional periods -both close to the shore (Silva et al, 2008) and in open ocean conditions (Guerreiro et al, 2014). In this regard, S. pulchra along with Helicosphaera carteri, C. mediterranea, and R. clavigera constitute a minority but persistent late summer-autumn assemblage in the S and SW Iberian coast that has been proposed by previous authors Silva et al, 2008Silva et al, , 2009Moita et al, 2010) as a tracer for ENACW of subtropical origin (Fiúza, 1983).…”

“…7 and 8). This species is regarded as a component of the lower limit of the photic zone in coastal settings (Baumann and Boeckel, 2013), and has been related to relatively nutrient-rich coastal waters in the SW Iberian Margin (Ferreira and Cachão, 2005;Silva et al, 2008;Guerreiro et al, 2013;Guerreiro et al, 2014). Its highest abundance coincides with maximum Chl a values and higher nutrient content (Figs.…”

“…Fossil coccolith records are being extensively used for climatic reconstructions along the western Iberian Margin (Parente et al, 2004;Flores et al, 2010;Incarbona et al, 2010;Amore et al, 2012;Palumbo et al, 2013). However, the few existing studies characterizing living coccolithophore community, distribution, abundance, and ecology in the water column are mostly based on central and southern areas (Cachão and Moita, 2000;Ferreira and Cachão, 2005;Silva et al, 2008;Moita et al, 2010;Guerreiro et al, 2013;Guerreiro et al, 2014), being scarce for northern locations (Abrantes and Moita, 1999;Moita, 2001). In this context, we present a year-long data set of coccospheres and free coccoliths based on monthly sampling at several depths at two different stations (one on the inner shelf and one on the outer shelf) across the NW Iberian Margin.…”

Towards a new and integrated approach to submarine canyon research

“…They have a lower diversity and are dominated by pioneer species, illustrating that the community stays in an early stage of ecosystem colonisation as a result of the regular deposition of turbidite sequences (Bolliet et al, 2013). Taking an entirely different perspective, Guerreiro et al (2013) present one of the first studies to characterise surface water coccolithophore assemblages in the context of an active submarine canyon and its associated physical oceanography. They find that the waters around Nazaré Canyon, offshore Portugal, are dominated in winter by two assemblages, distinguishing slightly more nutrient-rich coastal-neritic waters (influenced by surface water runoff) from the mixed oceanic waters advected onshore by the canyon.…”