Facilitation of Soft‐Bottom Benthic Succession By Tube Builders

Abstract

Controlled field experiments were used to test the effects of surface—deposit feeders on succession at the Skagit flats, an intertidal sandflat in northern Puget Sound. The tube builders Hobsonia florida (Polychaeta, Ampharetidae), Pseudopolydora kempi japonica (Polychaeta, Spionidae), and Lanais sp. (Crustacea, Peracarida) facilitate the recruitment of other taxa on 10—cm² azoic patches. Simulated animal tubes facilitated the immigration of Tanais sp. and oligochaetes. Macoma balthica, a tellinid bivalve, facilitated the immigration of H. florida, while inhibiting that of Tanais sp. These experiments clearly documented that facilitation rather than inhibition is the dominant process governing succession in the skatole community. The facilitation model of succession offers a viable alternate explanation for many soft—bottom benthic processes previously explained by the inhibition model.