Zostera marina and Zostera noltii formations of Black Sea shores, particularly luxuriant in the limans of the northern Black Sea and the Azov Sea. In the Black Sea, the dominant species of the Zostera biocenosis are Zostera marina and Zostera noltii (a total of 5 species of the genus Zostera) which form dense growths in bays and limans. There are 17-40 species of algae in the Zostera biocenosis which account for 1-30% of the phytocoenosis biomass. The most dominant of these species are: Ulva rigida, Chatemorpha chlorotica, Ectocarpus confervoides, Laurencia obtusa and Gracilaria verrucosa. The total number of macrozoobenthos species varies from 24 in the Kut part of Karkinitsky Bay to 70 in Kazachey Bay (Sevastopol). In the areas with higher freshwater input, the biocoenosis contains the crabs Macropipus holsatus and Rhithropanopeus harrisi tridentata, and the prawns Palaemon adspersus and Palaemon elegans. In Tendrovsky bay, other mass species are also: Abra ovata and Hydrobiidae. On the Crimean shelf the mass species are the gastropod molluscs Mohrensternia parva, Bittium reticulatum and the bivalve mollusc Mytilaster lineatus (Zaitsev and Aleksandrov, 1998).