Impact of dust addition on Mediterranean plankton communities under present and future conditions of pH and temperature: an experimental overview

Abstract. In low-nutrient low-chlorophyll areas, such as the Mediterranean Sea, atmospheric fluxes represent a considerable external source of nutrients likely supporting primary production, especially during periods stratification. These areas are expected to expand in future due lower nutrient supply from sub-surface waters caused by climate-driven enhanced stratification, further increasing role deposition new surface waters. Whether plankton communities will react differently dust warmer and acidified environment remains; however, an open question. The potential impact both present climate conditions was investigated three perturbation experiments Sea. Climate reactors (300 L) were filled with water collected Tyrrhenian Ionian Sea Algerian basin cruise conducted frame PEACETIME project May–June 2017. comprised two unmodified control tanks, tanks enriched Saharan analogue maintained under (+3 ?C) (?0.3 pH unit) conditions. Samples for analysis extensive number biogeochemical parameters processes taken over duration (3–4 d) experiments. Dust addition led rapid release nitrate phosphate, inputs much higher than phosphate. Our results showed that impacts different basins northwestern at least strong those observed previously, all performed coastal effects on biological stocks stations could not be attributed differences their degree oligotrophy but rather initial metabolic state community. Ocean acidification warming did drastically modify composition autotrophic assemblage, groups positively impacted acidification. Although biomass more heterotrophic environmental conditions, stronger mineralization suggests decreased capacity sequester CO2 following particles.