Description: The authors present data from studies of black mussels (Mytilus galloprovincialis) along the Bulgarian Black Sea coast. There were performed a total of 73 trawls in 6 mussel fields - Balchik, Galata, Byala, Emine, St. Vlas and Cape Maslen. The paper presents the data for size composition of the mussel in the separate fields, the amount yield per unit effort (15 minutes trawling) and the total stock of the fields equal to 92,482 tons. A comparison between different fields shows that the richest field is this in front of cape Emine. As a result of research it was found uneven distribution of the species in fields, as evidenced by fluctuations in the amount yields and the presence of empty trawlers