EFFECTS OF MORPHOLOGY, AGE, AND LOCATION ON HABITAT FUNCTION OF OYSTER REEFS: IMPLICATIONS FOR RESTORATION Martin Posey 1, Troy Alphin 1, Ted Wilgis 1 ; Heather Harwell 1,2, Joseph Sonnier 1, and Steven Artabane 1 1 University of North Carolina Wilmington 2 Virginia Institute for Marine Science
Restoration of Oyster Reefs Significant decline over past ½ century Pressure to restore lost reef areas and associated functions –Fishery –Filtration –Shoreline stabilization –Habitat and ecosystem functions However, variability in perceived success of restoration projects
Variety of factors may impact habitat function of restored reefs Oyster density and size distribution Reef size Reef height Reef complexity and edge relations Landscape factors –Reef fragmentation –Proximity to other habitats and access areas –Proximity to other reefs –Surrounding habitat characteristics (sediment, flow, connectivity to other areas, etc.)
Created and Reference Reefs – similarity, age and oyster density effects Everett's Bay –2004; 4 acre site; shallow subitdal Hewletts Creek –2003 (2005); 1 acre site; intertidal Hoop Pole Creek –2003; 0.5 acre site; intertidal Williston Creek - Core Sound –2004; 2 acre site - shallow subtidal
Proximity to channel and reef edge effects 5 of 6 common nekton exhibited reef edge responses 2 of 6 common nekton exhibited distance responses
Epifauna Responses to Distance and Edge
Edge and surface complexity
Epifauna Transient fish and decapods Infauna in adjacent areas
Indirect effect of reef complexity
Reef fragmentation 40% of common nekton and 50% of common epifauna exhibited significant abundance differences between smallest patch reefs and largest patch reefs.
Landscape and Morphology Considerations Morphology, location and other landscape considerations may affect reef habitat function Different aspects of morphology and landscape may differentially impact different faunal groups May be a consideration in restoration efforts –Diversity of placements and morphology –Some potential for targeted efforts