The importance of predation in shaping marine sessile communities at Williamstown, Victoria

Predation on newly settled individuals has been shown to shape sessile invertebrate communities of the northeast coast of North America. This study tests if this response can also be observed at other geographic locations that support different assemblage of sessile invertebrates. The effects of predation in early post-settlement assemblages were tested at two locations in Victoria; Workshops Pier, Williamstown and Queenscliff Pier, Queenscliff during the summer of 2005-2006. At each site, early post-settlement assemblages of sessile invertebrates were established and subsequently exposed to a series of predation exclusion treatments of varying durations. This dataset gives the abundances of sessile invertebrates on plates at Williamstown Pier after the initial 4 day settlement period, and after subsequent exposure to 3, 15 and 35 days exposure to three predation exclusion treatments. The predation treatments were i) uncaged, no predator exclusion, ii) full 2 mm mesh cage, total predator exclusion and iii) full 10 mm mesh cage, exclusion of large predators only. In addition two cage control treatments were established to identify if the cages themselves caused a change in the sessile invertebrate assemblages. Cage controls were partial cages constructed from both 2 mm and 10 mm mesh. The results indicated that, although predators were common, predation did not exert a strong influence on sessile invertebrate communities at Williamstown.