Coralline algae as habitat for marine invertebrates on rocky coasts near Bamfield, British Columbia

Abundance and distribution of epibiotic meiofauna and macrofauna were characterized for both intertidal and subtidal samples of articulated coralline algae (Rhodophyta: Rhodophyceae) at three sites in Barkley Sound, British Columbia, Canada. Intertidal samples were taken from transects located in low and high intertidal zones, both when these transects were exposed at low tide and when submerged at high tide. Overall, there was no difference in invertebrate assemblages from the low and high transects but there was a difference between samples taken when submerged and exposed. Multivariate regression trees correlating environmental variables to assemblage structure identified the presence of branching bryozoans and hydroids as being most influential in both the intertidal and the subtidal samples. Presence of these sessile organisms was associated with increased abundance of most motile organisms. This suggests that these branching organisms increase habitat complexity or act as food for associated invertebrates.