A Gram-stain-negative, strictly aerobic, non-flagellated, rod-shaped bacterium, designated GSB7(T), was isolated from seawater collected at the Yellow Sea coast of South Korea. Catalase and oxidase activities were positive. Growth occurred at pH 6.0-9.0 (optimum pH 7.0), 10-40 degrees C (optimum 30 degrees C) and with 0-8% NaCl (optimum 1-2%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GSB7(T) belonged to the genus Marivivens, showing the sequence similarities of 96.3, 96.1, and 96.0% with Marivivens niveibacter HSLHS2(T), Limimaricola hongkongensis DSM17492(T), and Marivivens donghaensis AM-4(T), respectively. The respiratory quinone was ubiquinone-10 and the major fatty acids were summed feature 8 (C-18:1 omega 7c and/or C-18:1 omega 6c), C-18:1 omega 7c 11-methyl, C-16:0 and C-10:0 3-OH. The polar lipids comprised phosphatidylglycerol, diphosphatidylglycerol, one unidentified aminolipid, and five unidentified lipids. The DNA G + C content calculated from the whole-genome sequence was 60.6 mol%. On the basis of phenotypic, chemotaxonomic and genotypic characteristics presented in this study, strain GSB7(T) is suggested to represent a novel species of the genus Marivivens, for which the name Marivivens aquimaris sp. nov. is proposed. The type strain is GSB7(T) (= KCTC 82026(T) = JCM 34042(T)).