Structure of fouling communities formed by Halichondria panicea (Porifera: Demospongiae) in the White Sea

Abstract

The structure of fouling communities formed by the sponge Halichondria panicea in the White Sea is described. On artificial substrates exposed in the sea for a long time, this sponge forms overgrowths on the colonies of long-lived organisms such as the mussel Mytilus edulis or the ascidian Styela rustica . The biomass of algae and sedentary animals (other than H. panicea ) on the substrate is markedly smaller in areas colonized by this sponge than in neighboring sponge-free areas. Conversely, the biomass of both sedentary and errant polychaetes is greater in H. panicea colonies than in adjacent fouling communities.