Spatial heterogeneity of epibenthos on artificial reefs: fouling communities in the early stages of colonization on an East Australian shipwreck

Artificial reefs, including purposefully sunken vessels, are widely regarded as significant ecological assets (Pickering et al. 1998; Baine 2001; Svane & Petersen 2001). The ecological values of artificial reefs encompass primarily the creation of habitat and the provision of refugia from commercial fishing (Santos et al. 2005; Boaventura et al. 2006; Moura et al. 2006; Ramos et al. 2006). Epibiota dominate the benthic assemblages on most artificial reefs, providing food resources for consumers, secondary habitat for other benthic invertebrates, and increased habitat complexity including shelter for fish (Bailey-Brock 1989; Mintz et al. 1994; Pickering & Whitmarsh 1997; Santos et al. 2005). Artificial reefs also function as coastal defense structures (Bacchiocchi & Airoldi 2003; Edwards & Smith 2005), and provide socio-economic benefits mainly as sites for recreational fishing and diving (Wilhelmsson et al. 1998; Airoldi et al. 2005; Pendleton 2005; Leeworthy et al. 2006). Artificial reefs are good model systems to assess colonization of newly created, artificial substrates (Cummings 1994; Svane & Petersen 2001; Perkol-Finkel & Benayahu 2005; Boaventura et al. 2006). Colonization of artificial structures occurs mainly through dispersal and settlement of larvae or spores (Underwood & Fairweather 1989;