Spatial variation in the biotic and abiotic filters of oyster recruitment: Implications for restoration

Attempts to restore marine ecosystems are increasing, but the success of projects remains variable. For marine invertebrates, the establishment of self-sustaining populations requires a larval supply as well as conditions that permit recruitment. Abiotic and biotic conditions that determine recruitment can vary across environmental gradients and have opposing or reinforcing effects. We assessed how predation and tidal inundation influence recruitment of the reef-forming oyster, Saccostrea glomerata, at 15 sites, 5 estuaries and 8 degrees of latitude in eastern Australia. Oysters recruited to all 15 sites, but their density displayed spatially variable effects of tidal inundation and caging. Effects of tidal inundation and caging were weakest at the two lower-latitude estuaries where recruitment was low overall, average temperature and turbidity were high and dissolved oxygen low. At higher-latitude estuaries, where abiotic conditions were more favourable for recruitment, recrui...