Figure 1.
Monthly-averaged (July 2004) MODIS chlorophyll a (in mg m−3) image showing the geographical location of Sedlo (white circle) and Seine (red circle) seamounts.
AzC: Azores Current.
Figure 2.
Bathymetry (m) of Sedlo (top) and Seine (down) seamounts showing stations positions.
Stations F and X1 at Sedlo and stations H and I at Seine are considered reference “far field” stations.
Figure 3.
Biomass variability between seamounts and far-field stations.
Water-column (0–150 m) integrated values (mg C m−2) averaged (±SE) from November 2003 and July 2004. (A) Total autotrophs versus total heterotrophs; (B) Autotrophs: microphytoplankton versus nanophytoplankton and picophytoplankton; (C) Heterotrophs: nanoplankton versus picoplankton.
Figure 4.
Vertical abundance distributions of micro and nanophytoplankton at Seine and Sedlo during different sampling periods.
Values correspond to averaged data (±SE) from all stations around each seamount (excluding the far-field stations).
Figure 5.
Vertical abundance distributions of eukaryotic and prokaryotic picophytoplankton at Seine and Sedlo during different sampling periods.
Values correspond to averaged data (±SE) from all stations around each seamount (excluding the far-field stations). Vertical average profiles of Chlorophyll a (Chl a; mg m−3) are also added in B, C, and D.
Figure 6.
Vertical abundance distribution of heterotrophic planktonic organisms during different sampling periods.
Values correspond to averaged data (±SE) from all stations around each seamount (excluding the far-field stations). Vertical average profiles of microplankton proteins (Pt; mg m−3) are also presented.
Table 1.
Integrated (0–150 m) average (SE) biomass (mg C m−2) of the different plankton groups for Seine and Sedlo seamounts and far-fields, during November, March (only Seine) and July.
Table 2.
Average plankton living biomass (B), total particulate organic carbon (POC), and contribution of B to POC at Sedlo and Seine seamounts.
Figure 7.
Intra-seamount variability in Seine.
Variability in (A) dinoflagellates biomass (mg C m−3) and (B) abundance (cells ml−1) during July 2004. Comparisons are made between the summit station (“A”), a seamount station at the east margin (“C”) and the northeast and southeast far-field stations “H” and “I”, respectively.
Table 3.
Shannon-Wiener Index (H), Species Richness (S) and Evenness (E) for microphytoplankton as a function of seamount and cruise.