Abstract— <p>Based on regular video observations conducted in 2016–2024 on technical structures in the aphotic zone of the Sea of Okhotsk, changes in the succession of fouling communities along the depth gradient (80–235 m) are described. For each station in the observation series, the age of the community, projective cover, and characteristic dominant species were determined. Throughout all the years of study, at all depths, the barnacle Chirona evermanni remained the main dominant species. At depths down to 115 m, fouling is characterized by a more uniform cover with high projective cover (up to 100% and above), as well as the presence of the soft coral Gersemia fruticosa and the ascidian Boltenia ovifera. At deeper sites (150–235 m), barnacles dominate, forming dense multi-layered aggregations that serve as a secondary substrate for other fouling organisms—mainly bryozoans and hydroid polyps. Comparison of data from stations of similar age showed that with increasing depth, the succession process becomes “stuck” at a stage corresponding to the 3-year-old fouling community at depths of 80–90 m. The obtained data demonstrate that depth is one of the key factors determining the succession dynamics and community structure of fouling in the aphotic zone of the Sea of Okhotsk</p>