Features of mussel (Mytilus galloprovincialis, Lamarck, 1819) population dynamics and biomass, when cultured on various collector types
The Black Sea mussel (Mytilus galloprovincialis Lamarck) biomass and abundance dynamics on artificial substrates with different relative surface area (area size of 1 linear meter of a given collector in relation to 1 m2 of an artificial substrate - S/S) were studied. The values of mussel reproductive potential during its settlement stage are characterized, which equaled 0.025 day-1 for type I of the collector, and increased up to 0.054 day-1 for type II. It is shown that, during the cultivation process, biological parameters of mussel populations varied significantly. It was determined that the abundance of molluscs on the collector of type I was steadily decreasing aft er spat settlement and subsequent cultivation process; it reached a certain stationary state, making up 258 ± 56 ind./m. By contrast, mussel biomass was increasing, and it reached a similar state under th e value of 2.86 ± 0.64 kg/m. These parameters were much higher on the collector of type II, where the stationary density was 1482 + 108 ind./m, and the biomass was 9.96 ± 1.70 kg/m. At the same time, individual mean length and mass parameters of mussels on the collectors were, respectively,45.1 mm and 11.7 m, whereas they were much lower (35.94 mm and 5.94 g) on the other ones. Based on the obtained data, it was concluded that during the mussel culture, the studied processes a re regulated by intrapopulation factors, depending on population density, that is intraspecific competition for a substrate among the specimens.