Trophic Diversity of Plankton in the Epipelagic and Mesopelagic Layers of the Tropical and Equatorial Atlantic Determined with Stable Isotopes

摘要: Plankton living in the deep ocean either migrate to surface feed or situ on other organisms and detritus. Planktonic communities upper 800 m of tropical equatorial Atlantic were studied using natural abundance stable carbon nitrogen isotopes identify their food sources trophic diversity. Seston zooplankton (>200 µm) samples collected with Niskin bottles MOCNESS nets, respectively, epipelagic (0–200 m), mesopelagic (200–500 lower layers (500–800 m) at 11 stations. Food for plankton productive zone influenced by NW African upwelling Canary Current different from those oligotrophic zones. In latter, during night was enriched heavy relative day samples, supporting active migration layers. Isotopic niches showed also zonal differences size (largest north), mean diversity zone), sources, number levels zone). The observed changes niche overlap (up 71% between but <50% layers) support prevalence feeding zooplankton.