Succession on marine hard substrata: the adaptive significance of solitary and colonial strategies in temperature fouling communities

Abstract

Community development is analysed in 7 temperate fouling communities in Puget Sound, Washington, USA. In contrast to previous investigations of succession on marine hard substrata, solitary animals dominated the available primary space in these communities at the expense of their colonial counterparts. A series of testable hypotheses are proposed to explain these findings in light of previous predictions, current successional theory and results from other investigations of temperate fouling communities. The hypothesis that we favor at present involves an inhibition-type successional process, one which leads to a community composed of species that are longer-lived or that exhibit strong selfreplacement tendencies. In Puget Sound fouling communities, many of the major solitary species are characterized by such features, and this may account for their eventual dominance. The question of whether solitary or colonial animals dominate temperate fouling communities remains unanswered and is in need of further investigation before the full evolutionary and biogeographical implications can be resolved.