The project seeks to study the biogeochemical consequences of (1) the vertical mixing and the consequent planktonic bloom in the oceanic subtropical waters around the Canary Islands, (2) the influence of the lunar cycle observed in zooplankton in the transport of organic carbon towards the mesopelagic zone, and (3) the process of natural fertilization with iron promoted by the deposition of ... Saharan dust which is produced in several events during winter around the Canary Islands, coinciding with the vertical mixing and the planktonic lunar cycles. The objective of the project is the assessment of gravitational and active fluxes, the latter promoted by diel vertical migrants, during the late winter bloom. Our hypothesis is that vertical mixing promoting the late winter bloom, iron fertilization through dust deposition, and the consequent increase in production should be, in part, shunted to the mesopelagic zone in synchrony with the lunar cycle. We seek to quantify the fate of production, the magnitude of the active flux during the different phases of the lunar cycle and its comparison with the gravitational flux. The working plan of this project will consist in sampling at weekly intervals the late winter bloom (from December to June). This study will provide a privileged information about the fate of a bloom (induced or not by iron). This is of relevance in oceanography due to the aim to carry on massive fertilization with iron to slow global warming.