The coccolithophore summer–autumn assemblage in the upwelling waters of Portugal: Patterns of mesoscale distribution (1985–2005)

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

“…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). Apart from H. carteri, this assemblage was observed further offshore in November 2011 (Fig.…”

“…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.…”

Coccolithophore variability from the Shackleton Site (IODP Site U1385) through MIS 16-10

“…Coccolithophores are the most tolerant group to these hydrological changes if compared with diatoms, that dominate during early spring to autumn upwelling events, and with dinoflagellates that benefit from maximum stratification during summer (Silva et al, 2009). In the area, with the exclusion of the periods of actual upwelling conditions, coccolithophores dominate the phytoplankton throughout the year, either during autumn and winter, when upwelling weakened and SST increases, and during short transition period from upwelling (summer) to downwelling (autumn) seasons (Abrantes and Moita, 1999;Silva et al, 2009;Moita et al, 2010).…”

Surface-ocean dynamics during eccentricity minima: a comparison between interglacial Marine Isotope Stage (MIS) 1 and MIS 11 on the Iberian Margin

“…Our choice to use coccolithophores as paleoclimate proxy is related to their ability in recording the smallest climatic fluctuations thanks to their sensitive response to SST, nutrient availability, salinity, and sunlight changes (e.g., McIntyre and Bé, 1967;Baumann and Freitag, 2004;Moita et al, 2010;Poulton et al, 2017;Guerreiro et al, 2017;Ausin et al, 2018). Previous studies demonstrated their role to reconstruct changes in the main surface-ocean currents off Portugal, in particular in combination with alkenones data (Amore et al, 2012;Palumbo et al, 2013a, b).…”