Abstract <p>The paper discusses the theoretical and practical aspects of the relationship between biooptical parameters (chlorophyll <i>a</i> concentration, colored dissolved organic matter, turbidity) and the distribution of dissolved gases (methane, helium, hydrogen, hydrogen sulfide) in seawater. Comprehensive studies of the gas-geochemical, hydrological, and biooptical parameters of the shallow northeastern shelf of Sakhalin Island (Sea of Okhotsk) are based on data obtained during cruise 68 of the R/V <i>Akademik Oparin</i> in August 2023. It has been shown that during the warm period of the year, the study area includes waters with various biooptical characteristics, influenced by river runoff, hydrocarbon-rich shelf areas, active phytoplankton development, and water dynamics. Biooptical measurements make it possible to distinguish the main branch of the East Sakhalin Current and its shelf branch, in which increased concentrations of dissolved gases are present, emanating from benthic sources on the eastern shelf of Sakhalin Island.</p>