oa Spatial Distribution, Abundance and Proxy Signals from Lipid Biomarkers in the Water Column of the Iberian Margin

This study examines spatial distribution, abundance and proxy signals from lipid biomarkers in the water column of the Iberian margin. By analysing lipid biomarkers in the water column, this study provides a deeper understanding of the pathways and controls affecting their transfer from source to sink, thus improving the robustness of biomarker-based paleoenvironmental reconstructions. A total of 38 water samples were filtered from six stations across a 3000m depth range using Stand Alone Pumps (SAP) during the JC089 cruise in August 2013. An aliquot from each filter was extracted and Lipids were analysed for n-alkanes, alkenones, long chain fatty acids and glycerol dialkyl glycerol tetraethers (GDGTs). Results shows high biomarker concentration in the upper photic zone and gradually decreasing with the depth. Alkenones most abundant in nearshore and alkenone derived SST exhibit a cold bias compared to CTD data in the same depths suggesting alkenones are influenced by various hydrodynamic processes varying between nearshore offshore oceanographic settings.