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To help determine whether planktonic eggs of fishes on the West Florida Shelf (WFS) are retained locally or exported elsewhere, we collected fish eggs by plankton net from 17 locations (stations) and identified them using DNA barcoding. We then entered the station coordinates into the West Florida Coastal Ocean Model (WFCOM) and simulated the trajectories of the passively drifting eggs over 2 weeks at three depths (surface, midwater, and near bottom). The results indicated there were two groups of trajectories: a nearshore group that tended to be retained and an offshore group that tended toward export and potential long‐distance dispersal. We also found evidence of a relationship between retention and higher fish‐egg abundance; nearshore stations were associated with higher fish‐egg abundances and higher retention. We suggest this is the result of (1) increased spawning in high‐retention areas, (2) increased drift convergence in high‐retention areas, or both processes acting together. Community analysis using SIMPROF indicated the presence of a depth‐related (retention‐related) difference in species assemblages. Fish‐egg species were also categorized as pelagics or non‐pelagics; there was no evidence of pelagic species being more likely to be exported.

Restoration of degraded estuarine oyster reefs typically involves deploying recycled oyster shell. In low‐salinity, low‐predation areas of estuaries, high‐volume shell deployments are known to improve flow conditions and thus oyster survival and growth. It is also hypothesized that the physical structure of restored reefs could suppress foraging by oyster predators in high‐salinity, high‐predation zones. That hypothesis is untested. Given limited resources, it is important to determine how much shell is needed for successful restoration and whether there are diminishing returns in shell addition. In Apalachicola Bay, Florida, we manipulated shell volume on an oyster reef to create three 0.4 ha areas of low (no shell addition), moderate (153 m³shell), and high (306 m³shell) habitat structure. We repeated experiments and surveys over 2 years to determine if restoration success increased with habitat structure. Predation on oysters was greater on the non‐shelled area than on the reshelled reefs, but similar between the two reshelled reefs. Oyster larval supply did not differ among the reef areas, but by the end of the experiment, oyster density (per unit area) increased quadratically with habitat structure, plateauing at high levels of structure. Model selection indicated that the most parsimonious explanation for these patterns was that increased habitat structure reduced predation and increased overall recruitment, but that the higher reshelling treatment did not have better outcomes than moderate reshelling. Thus, restoration could be optimized by deploying a moderate amount of shell per unit area.