Elevated production of dimethylsulfide resulting from viral infection of cultures of Phaeocystis pouchetii

<jats:p>The effects of viral lysis on dimethyl sulfide (DMS) and particulate and dissolved dimethylsulfoniopropionate (DMSP) concentrations were studied in batch cultures of <jats:italic>Phaeocystis pouchetii</jats:italic> infected with a strain‐specific viral isolate. After 20 h, DMS concentration had increased by fourfold over the levels observed in the control cultures, and this increased to eightfold 45 h after addition of viral particles. The results suggest that viral lysis of DMSP‐containing phytoplankton cells should be considered alongside autolysis, grazing, and bacterial activity as a process that can influence DMS concentrations in seawater. Further research will be necessary to determine the importance of viruses in the biogeochemical DMS cycle in the natural environment.</jats:p>