Taylor, Jaclyn C.. Evaluation of the ecological value of constructed intertidal oyster reefs and aquaculture structures in Delaware Bay. Retrieved from https://doi.org/doi:10.7282/T3571C91
DescriptionThe Cape Shore on the New Jersey side of Delaware Bay USA is an extensive high-energy polyhaline intertidal zone that consistently receives the highest oyster (Crassostrea virginica) settlement in the Bay. Intertidal oyster reefs in lower Delaware Bay are ephemeral, and it is generally assumed that oyster mortality due to predation, disease and winter ice scouring inhibit their persistence. If protected, however, oysters survive and grow well; hence, oyster aquaculture is developing at the site. In June 2006, shell-bag oyster reefs of varying height were constructed on the intertidal sand flats in lower Delaware Bay to determine the potential for oyster reef restoration in this temperate estuary. Oysters survived a heavy formation of ice during winter 2007, but shifting sediments nearly buried the shortest reef by April 2007, a process that may be important in limiting the development of oyster reefs in this system.
In May 2007, six 2-layer shell-bag reefs were constructed. These constructed reefs as well as rack and bag oyster culture systems provided semi-permanent structures that form potential habitats for motile fauna on the sand flats of the Cape Shore. To assess the habitat potential of these structures, constructed reefs, aquaculture racks and adjacent sand flats were monitored for utilization by motile macrofauna using wire mesh traps, crab pots and eel traps from May through October 2007. Species richness for aquaculture racks (25 species) and shell-bag reefs (22 species) were comparable and significantly greater than on the sand flats (17 species). Seven species were unique to aquaculture racks. Species abundance was five times greater around aquaculture racks and three times greater around shell-bag reefs compared to sand flats. Intertidal oyster reefs and aquaculture structures increased habitat complexity, attracted similar assemblages of motile macrofauna and supported an increased species abundance, biomass and species richness compared to sand flats. Based on these metrics, oyster aquaculture rack and bag structures are comparable habitat to intertidal oyster reef habitat in Delaware Bay.