Salt marsh shoreline geomorphology influences the success of restored oyster reefs and use by associated fauna

• Published in: Restoration ecology 2019-11, Vol.27 (6), p.1429-1441
• Main Authors: Keller, Danielle A., Gittman, Rachel K., Brodeur, Michelle C., Kenworthy, Matthew D., Ridge, Justin T., Yeager, Lauren A., Rodriguez, Antonio B., Fodrie, F. Joel
• Format: Article
• Language: English
• Subjects: Animal behavior; Blue crabs; Brackishwater crustaceans; Coastal inlets; Crustaceans; Ecological monitoring; Erosion; Erosion rates; Escarpments; Fauna; Fetch; Fishing nets; Foraging habitats; Gastropoda; Geomorphology; Gillnets; Habitats; Hydrodynamics; Interspecific relationships; Landscape; Marine crustaceans; Marine molluscs; Mollusks; Nekton; Nets; oyster recruitment; Oysters; Piscivores; Population density; Predation; Predators; Prey; Reefs; Restoration; Salt marshes; Saltmarshes; Shorelines; Slope; Snails; Spat; structured habitat; Success; tidal creek; Trawlnets
• ISSN: 1061-2971; 1526-100X
• DOI: 10.1111/rec.12992

Restoration is increasingly implemented as a strategy to mitigate global declines in biogenic habitats, such as salt marshes and oyster reefs. Restoration efforts could be improved if we knew how site characteristics at landscape scales affect the ecological success of these foundation species. In this study, we determined how salt marsh shoreline geomorphologies (e.g. with variable hydrodynamic energy, fetch, erosion rates, and slopes) affect the success of restored intertidal oyster reefs, as well as how fauna utilize restored reefs and forage along marsh habitats. We constructed oyster reefs along three marsh shoreline geomorphologies in May 2012: 1) “creek” (small‐fetch, gradual‐sloped shoreline), “ramp” (large‐fetch, gradual‐sloped shoreline), and “scarp” (large‐fetch, steep‐sloped shoreline). Following recruitment, oyster spat density was greatest on ramp reefs; however, 2 years later, the highest adult oyster densities were found on creek reefs. Total nekton and blue crab catch rates in trawl nets were highest in the creek, while piscivore catch rates in gill nets were highest along the scarp shoreline. We found no difference in predation on snails in the salt marsh behind constructed reef and nonconstructed reference sites, but there were more snails consumed in the creek shoreline, which corresponded with the distribution of their major predator—blue crabs. We conclude that oyster reef construction was most successful for oysters in small‐fetch, gradual‐sloped, creek environments. However, nekton abundance did not always follow the same trends as oyster density, which could suggest constructed reefs may offer similar habitat‐related functions (prey availability and refuge) already present along existing salt marsh borders.