Maerl (or marl) is a collective name for Coralline red algae with a certain growth habit. Maerl grows at a rate of ~1mm per year. It accumulates as unattached particles and forms extensive beds in suitable sublittoral sites.

Maerl (or marl) is a collective name for Coralline red algae with a certain growth habit. Maerl grows at a rate of ~1mm per year. It accumulates as unattached particles and forms extensive beds in suitable sublittoral sites.