Planktonic archaea in suspended particulate matter from Northwestern Pacific Ocean surface waters

Planktonic archaea include predominantly Marine Group I Thaumarchaeota (MG I) and Marine Group II Euryarchaeota (MG II), which play important roles in the oceanic carbon cycle. MG I produce specific lipids called isoprenoid glycerol dialkyl glycerol tetraethers (GDGTs), which are being used in the sea surface temperature proxy. Although MG II are the most abundant planktonic archaeal group in surface water, their lipid composition remains elusive because of the lacking of pure cultures. We coupled the archaeal 16S rRNA gene abundance and sequencing to archaeal lipid analysis on surface water samples from Northwestern Pacific Ocean (NWPO) and East China Sea (ECS) in order to determine the contribution of MG II archaea on GDGT distribution in these regions.