Two separate studies in different oceanic regions provide evidence for the production of methyl bromide (CHBr) by the prymnesiophyte Phaeocystis. A sampling program to study the seasonal cycle of CHBr in a coastal area demonstrated that the seawater was supersaturated with respect to CHBr for over 3 months of the year. The greatest saturation was observed during a bloom of Phaeocystis. Also, in situ field measurements demonstrated that CHBr was supersaturated over a large region of the northeast Atlantic. A positive correlation was observed between CHBr and dimethylsulphoniopropionate (DMSP), indicating that there was a source common to both compounds. An accessory pigment, hexanoyloxyfucoxanthin, which indicates the presence of prymnesiophytes, also correlated positively with CHBr.
- methyl bromide
- air-sea gas exchange