Bioaerosols Impacts on Ocean Biogeochemistry

Abstract:

Atmospheric deposition of trace elements, nutrients and airborne microbes to the ocean can significantly modify seawater chemistry and influence oceanic productivity and biogeochemistry. However, mounting evidence suggests that the response of phytoplankton to atmospheric deposition depends on the chemical and biological composition of the aerosols and varies across different ecosystem settings. To determine if and how bioaerosols influence phytoplankton community structure and biogeochemistry in the Ocean we analyzed the response of native microbial populations to “live” and UV-treated (killed) aerosol additions. This was done using incubation experiments with natural phytoplankton assemblages with different sources and amounts of aerosol additions. We found that airborne microbes contribute to both carbon and nitrogen fixation and that they also impact phytoplankton composition due to competition and/or viral infection, in low nutrient low chlorophyll oligotrophic systems. The impact of airborne microbes on marine ecosystems should be considered and further studied. Changes in atmospheric deposition and aerosol composition that are impacted from natural and anthropogenic change could therefore have effects on ocean productivity, biogeochemistry, and biogeography.