Data from: 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, recruit density displayed
tidal elevation gradients that were dependent on caging and time.
Initially, recruit density decreased with tidal inundation (and exposure
to finfish predators), in the uncaged but not the caged treatment.
However, over time the elevation gradient disappeared, and recruitment and
survival of oysters was greater in caged than uncaged treatments
irrespective of elevation. Synthesis and applications: Our results suggest
that both abiotic (i.e. temperature, turbidity and dissolved oxygen) and
biotic (i.e. predation) factors can negatively influence oyster
recruitment and, hence, restoration success. Consequently, oyster reef
restoration projects should be planned to prioritise sites with low
turbidity, high dissolved oxygen and low predation unless these stressors
can be mitigated. Restoration projects that are designed with knowledge of
local stressors are more likely to be successful.