Classic paradigms in a novel environment: inserting food web and productivity lessons from rocky shores and saltmarshes into biogenic reef restoration

Gradients in competition and predation that regulate communities should guide biogenic habitat restoration, while restoration ecology provides opportunities to address fundamental questions regarding food web dynamics via large‐scale field manipulations. We restored oyster reefs across an aerial exposure gradient (shallow‐subtidal‐to‐mid‐intertidal) to explore how vertical gradients in natural settlement, growth and interspecific interactions affected the trajectory of man‐made shellfish reefs. We recorded nearly an order‐of‐magnitude higher oyster settlement on the deepest (subtidal) reefs, but within a year abundance patterns reversed, and oyster densities were ultimately highest on the shallowest (intertidal) reefs by over an order‐of‐magnitude. This reversal was due to (i) significantly elevated survivorship on intertidal reefs and (ii) larger surviving oysters on intertidal reefs. These patterns are likely to have developed from greater levels of biofouling and predator abundance (e.g. stone crabs, gastropods) on deeper reefs where aerial exposure was