The variability of the Cape Boujdor upwelling and its relationship with the Cape Blanc frontal zone (Morocco)

The Cape Boujdour and Cape Blanc upwelling areas are a favorable environment for the spawning of multiples pelagic fish species, due to their particular hydrological features, which provide a high productivity to this region. The study area is subdivided into three successful regions with a different hydrological characteristic. The first area (Boujdour – Dakhla) is known for the coastal upwelling of deep water in northern part of the Moroccan Atlantic Ocean. The second area in the middle (Dakhla-Cape Barbas) presents a vertical stratification. The filamentous drift of the waters and the resurgences toward offshore favor photosynthesis far from the coast and promotes high productivity. The presence of front between different water masses characterizes the third area between Cape Barbas and Cape Blanc in southern part of the Moroccan Atlantic coast. An advection variability distinguishes this part from north to south of the upwelled North Atlantic Central Water in Cape Boujdour and from south to north of the South Atlantic Central waters rich in nutrients, deficient in oxygen and high Chlorophyll concentration. This situation leads to a biological richness by the apparition of Thermohaline circulation front at the Cape Blanc area, which depends on the Inter Tropical Convergence Zone temporal and spatial variability.