Heterotrophic prokaryotes as drivers of exopolymeric particles in the Mediterranean Sea and the Subtropical NorthEast Atlantic Ocean

• Main Authors: Mazuecos, Ignacio P., Arístegui, Javier, Gasol, Josep M., Baños, I., Espino, Minerva, Hernández, N., Montero, María F., Reche, Isabel
• Format: Still Image
• Language: unknown
• Published: Association for the Sciences of Limnology and Oceanography 2015
• Subjects: Northeast Atlantic
• Online Access: http://hdl.handle.net/10261/135922

Aquatic Sciences Meeting, Aquatic Sciences: Global And Regional Perspectives - North Meets South, 22-27 February 2015, Granada, Spain Exopolymeric particles (EP) affect both carbon export into deep waters and gas exchange at the surface microlayer. We describe the distribution of EP in the water column, from surface to the bottom, across the Mediterranean Sea and the subtropical Northeast Atlantic Ocean. EP concentrations ranged from 5.3 to 81.7 μg XG eq l-1 in the epipelagic zone (0-200 m), from 1.2 to 34.7 μg XG eq l-1 in the mesopelagic zone (200-1000 m) and from 0.6 to 15.9 μg XG eq l-1 in the bathypelagic zone (>1000 m). In general, EP concentrations were significantly lower in the Eastern Mediterranean basin compared to the Western Mediterranean and the subtropical Northeast Atlantic Ocean, coinciding with lower concentrations in phytoplankton and heterotrophic prokaryotic abundances. The relationships between EP and chlorophyll a in the epipelagic zones varied greatly, being very inconsistent among basins. In contrast, EP distributions in the epipelagic and mesopelagic waters were consistently related to heterotrophic prokaryotic abundance, particularly in the Western Mediterranean basin. Our results suggest a paramount role of heterotrophic prokaryotes in promoting EP production both in epipelagic and mesopelagic waters of these marine regions Peer Reviewed