The article highlights the concern over the invasion of green microalgae of the genus Coccomyxa in the Russian waters of the Black Sea, which poses a significant threat to the region's mussel population and mariculture farms, where various delicious species are cultivated. These microalgae cause shell lesions and inflammatory issues in mollusks, leading to a reduction in their lifespan. With reports of this parasite appearing in new species of bivalves globally, there is a lack of programs aimed at its identification. However, scientists at the Federal Research Center Institute of Biology of the Southern Seas of the Russian Academy of Sciences have received a grant to conduct a comprehensive assessment of the parasite, Coccomyxa parasitica, and its adaptation to new environments, particularly the Black Sea. This research could aid in predicting the parasite's spread and developing strategies for its detection and prevention, thereby protecting Crimean mussel farms and the entire aquaculture industry in the region.