Sydney Harbour_oyster communities and wave energy

Nine sites with naturally occurring Saccostrea glomerata populations growing on sandstone rocky shores were surveyed in Sydney Harbour. At each location, the maximum wave energy was measured and the surface area and associated invertebrate community of plots with oyster habitat (n=6) and invertebrates in plots without oyster habitat (n=6) were surveyed. The survey was followed by a manipulative study to disentangle direct versus indirect effects of wave energy on oysters and their associated communities. Experimental units with no-, low- and high-complexity defaunated oyster habitat were deployed at two each of low- and high-wave energy sites for four months after which the richness, abundance and diversity of the final community was quantified. Hatchery reared oysters were also deployed and the condition index measured for oysters at each site.