Bivalve mollusks in the sediments of the Anapa Bay Bar (Black Sea) in October 2010

Emissions of sand and shelly ground from the adjacent sea bottom partly compensate for this process. Concentration of carbonates may reach up to 50% in beach sands, and most of these carbonates are of mollusk origin.

The major deposit formation role belongs to the key bivalve species: Chamelea gallina (Linnaeus, 1758). Average biomass of this mollusk species reaches up to 450 g/m**2 at depths 5-10 m. The other two subdominating mollusk species, bivalve Donax trunculus (Linnaeus, 1758) and gastropod Rapana venosa (Valenciennes, 1846), may impact as 16 g/m**2 and 6 g/m**2, respectively.