Individual variability of growth of the cultivated Mytilus galloprovincialis Lam. in various habitat conditions of the Black sea coastal zone

Abstract

Bivalve mollusc M. galloprovincialis is one of the most common marine animals in the Azov-Black Sea basin. The shell length increment of mussels is indicators of the degree of favourable environmental. The aim of the study the individual growth of M. galloprovincialis mussel in various habitat conditions. To determine the individual growth of mussel, a labelling technique was used. 50 individuals of one-sized 35 and other sized 60-mm mussels were placed into separate sectors of two oyster cages. One cage was hung out in the clear water area of a mussel–oyster farm, the second in a polluted apex part of the harbour. Mussels with a shell length of 35 mm from the mussel–oyster farm were 6 times higher in the shell length increment than mussels from harbour, in the size group of 60 mm were 3.5 times higher. In the studied water areas during the experimental period, the growth of mussels of the two size groups was uneven. In adverse harbour conditions, mussel growth slowed down, stopped and sometimes had ‘negative growth’ values were noted. The shell length increment of mussels was influenced by the ecological state of the environment (pollution), nutritive base, reproductive state and hydrodynamic regime of the compared water areas. The shell length increment of M. galloprovincialis reflects the adaptation of mussels to a complex of environmental factors and can be used as a one of the parameters of bioindication of water areas.