The aim of the cruise with RV Maria S. Merian (MSM33) was to study the variability of six halocarbons (CH3I, CHCl3, CH2Br2, CH2ClI, CHBr3 andCH2I2) and DMS in the Black Sea which is a comparably less studied area in the field of halocarbon research. Water samples were taken with a CTD-rosette sampler from the surface as well as from the depth with Chl-a maximum values. Furthermore, the vertical distribution of halocarbons in the water column was measured at selected locations. Several physical and biological parameters were additionally analysed.