Viability of Prokaryotes in Nascent Aerosolized Sea Spray Across the Eastern Mediterranean Sea

This study investigates the spatial distribution of viable prokaryotes and virus-like particles (VLP) in nascent sea spray aerosols (SSA) across the Eastern Mediterranean Sea, including through mesoscale eddies, and two coastal oligotrophic sites. The percentage of viable prokaryotic cells ranged from 5% to 33% throughout the cruise transect. We observed positive coupling between the abundance of viable prokaryotes (∼1.9 × 10² to 4.4 × 10⁴ cells m⁻³) and surface water chlorophyll-a levels and a negative relationship with temperature, reaching statistically significant maximal values in the relatively colder and algal-richer stations by a factor of 1.3. VLP in SSA ranged from ∼9.5 × 10⁴ to 1.2 × 10⁶ m⁻³, and were more enriched over oligotrophic warm waters. Comparative analyses of viability in the SSA and surface water showed a statistically significant decrease in prokaryote viability upon aerosolization from 35% to 29%, although their carbon uptake rate remained similar (121–145 fg C viable cell⁻¹ d⁻¹). These results provide new insights into prokaryote viability in nascent marine aerosols, emphasizing the need for further research on long-term survival and ecological roles of aerosolized microbes.