Inter-annual fluctuations in the recruitment rate and size–age structure are typical for marine bivalve beds. Until now there is no common opinion about the causes of this variability. One of them may be related to the adult–larval interactions in mollusk populations. To test this suggestion and to reveal the possible causes of inter-annual instability in bed recruitment level we analyzed the long-term (9–30 years) dynamics of the 16 size–age structure of 22 populations of 9 bivalve species in the White Sea. Inter-annual variability in the successful recruitment was typical of most studied bivalve beds. This phenomenon was apparently caused, on the one hand, by the intensity of molluscs’ intraspecific interactions, and on the other (no less), by the juvenile survival in their first winter. The bivalve stationary beds in the White Sea are likely the exception from the general rule. They can be formed in case of a relatively stable level of annual recruitment with a decrease in intensity of intraspecific competiti