A Gram-stain-negative, obligate aerobic, non-motile and rod-shaped bacterium, designated MME-070T, was isolated from a tidal flat near Muui-do, Incheon, Republic of Korea. This bacterium belonged to the Roseobacterclade within the family Rhodobacteraceae. The isolate grew at 20-40 °C, pH 7.0-9.0 with 1-5 % (w/v) NaCl. Optimal growth required 2-3 % (w/v) NaCl at 25-30 °C and pH 8.0. The 16S rRNA gene sequence of strain MME-070T was most closely related to Roseovarius aestuarii SMK-122T (96.9 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain MME-070T clustered with the genus Roseovarius. The sole respiratory quinone was Q-10. Polar lipids were phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, unidentified aminolipid and some unidentified lipids. Major cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), 11-methyl C18 : 1ω7c and C16 : 0. The genomic DNA G+C content of the type strain was 63.6 mol%. Based on polyphasic taxonomic analysis, strain MME-070T is proposed to represent a novel species of the genus Roseovarius, for which the name Roseovarius faecimaris sp. nov. is proposed. The type strain is MME-070T (=KCCM 43142T=JCM 30757T).