Organic matter dynamics in the Canary Current

Abstract

The distribution and cycling of biogenic organic matter in the Canary Current Large Marine Ecosystem is strongly affected by the intense mesoscale activity of the area, mainly in the form of meanders, filaments and eddies, and their interaction. Filaments contribute significantly to the offshore export of coastal upwelling primary production in the form of dissolved and suspended organic matter. Cyclonic and anticyclonic eddies (mostly generated by flow perturbation by Madeira and the Canary Islands) may enhance the production of fresh organic matter during their early stages of formation, favouring the vertical sinking of particles. Additionally, they may accumulate and transport suspended particles and dissolved organic matter through a permanent westward corridor of eddies. Organic matter deposited in coastal sediments is also transported laterally to the adjacent ocean in the form of intermediate and bottom nepheloid layers resulting from the erosion of the shelf and slope sediments by the intense and variable coastal currents. All these mechanisms contribute exporting the biogenic materials produced in the coast hundreds of kilometres into the open ocean.