Efecte de la deposició atmosfèrica sobre els microorganismes del Mar Mediterrani

Abstract

Atmospheric depositions represent an important source of dissolved nutrients to the offshore global ocean and can increase primary and bacterial productivity and thus carbon uptake and bacterial biomass. The Mediterranean Sea is an ideal marine environment for studying the role of aerosols and associated microbes on surface ocean microorganisms for multiple reasons. First, the Mediterranean Sea is subjected to relatively high aerosol deposition throughout the year. Secondly, it is an oligotrophic environment with low inorganic nutrients and low autotrophic and heterotrophic activity. Thus, any external input of micro/macronutrients, along with aerosols-associate microbiota, can have a substantial effect upon interaction with the ambient microbial populations. Although the effect of dust deposition has been extensively studied in the NW Mediterranean, the effect of anthropogenic aerosols is still quite unknown. For this reason, we carried out an experiment to study the effect of anthropogenic-derived particles, which we will refer as anthropogenic aerosols and have a mainly European origin, in the NW Mediterranean. Anthropogenic aerosols in the Barcelona area can be a major source of nitrogen and phosphorous to the atmosphere and are much richer than Saharan particles in organic carbon. On the other hand, anthropogenic aerosols tend to contain high amounts of copper, lead and other trace metals, which are known to be toxic to microbiota at high concentrations. Thus, one way or another, an effect of anthropogenic aerosols on marine microbiological communities’ abundance is expected. [...]