Field experiments on population regulation in intertidal limpets of the genus Acmaea.

The numbers of limpets on pier pilings in the intertidal zone were reduced to almost zero and increased to almost double the numbers on control pilings to determine if densities are regulated. Densities on experimental pilings returned to that of control pilings in 3 and 8 months in two experiments. Mechanisms which could explain this readjustment of densities include density dependent vertical migration, cannibalism of newly settled young and the selection of suitable substrate by larval limpets.