Strong linkages between dimethylsulphoniopropionate (DMSP) and phytoplankton community physiology in a large subtropical and tropical Atlantic Ocean data set

We present an extensive data set of dimethylsulphide (DMS, n = 651) and dimethylsulphoniopropionate (DMSP, n = 590) from the Atlantic Meridional Transect program. These data are used to derive representative depth profiles that illustrate observed natural variations and can be used for DMS and DMSP model-validation in oligotrophic waters. To further understand our data set, we interpret the data with a wide range of accompanying parameters that characterize the prevailing biogeochemical conditions and phytoplankton community physiology, activity, taxonomic composition, and capacity to cope with light stress. No correlations were observed with typical biomarker pigments for DMSP-producing species. However, strong correlations were found between DMSP and primary production by cells >2 m in diameter and between DMSP and some photo-protective pigments. These parameters are measures of mixed phytoplankton communities, so we infer that such associations are likely to be stronger in DMSP-producing organisms. Further work is warranted to develop links between community parameters, DMS, and DMSP at the global scale.