Reconstruction of productivity gradients in the Canary Island Region off Morocco by means of sinking particles and sediments.

Abstract

The Canary Islands region is characterised by a productivity gradient that is formed by the eutrophie trade wind driven upwelling region on the Moroccan shelf, highly productive filament regions, and oligotrophic conditions further offshore. Sinking particles, surface sediments and sediment cores were investigated with the aim to reconstruct productivity gradients in this region. Organic carbon, carbonate and stable carbon isotope ratios served as proxies for the sedimentation of biogenic matter. In addition, the fairly new method of sedimentary stable nitrogen isotope ratios as indicator of nutrient utilisation was applied.