Restoration Programs: Oyster Reefs

• Introduction
• Restoration methods
• Restoration sites
• Related research programs
• Restoration partners and sponsors

Introduction

Our oyster reef restoration activities seek to create three dimensional oyster reefs that mimic natural Chesapeake oyster reefs or rehabilitate existing oyster habitat. In either case, our goal is to restore the physical structure to encourage oyster success and, subsequently, successful development of complex ecological communities that Chesapeake Bay oyster reefs traditionally supported. Habitats or areas are usually selected as restoration sites on the basis of both historical biological data (did this area traditionally support viable natural oyster populations?) and local oceanographic data (are the currents at the site suitable to maintain low sedimentation rates and transport regular supplies of young oysters to the site from local natural populations?). Thus, the vast archive of oyster monitoring data collected by our program integrates seamlessly with our restoration programs.

Restoration methods

Our oyster reef restoration efforts to date have been primarily oyster shell plants on footprints of historic oyster reefs. Sites have been chosen based on watershed conditions, salinity and temperature ranges, as well as disease prevalance. These reefs have been built primarily with clean oyster shell washed overboard from barges. The oldest of these restored reefs, Palace Bar Reef in the Piankatank River (Figure 1) is home both oysters and numerous other species. Since the construction of Palace Bar Reef in 1993, over 80 other oyster reefs have been built in the lower Chesapeake Bay by the Virginia Marine Resources Shellfish Conservation Division led by Dr. James Wesson. These reefs are constructed primarily from oyster shell because oyster shell reefs provide natural settlement habitat for oysters and create a complex three dimensional physical matrix with a variety of nooks and crannies that may be occupied by many other animals. Oyster reefs are not just piles of shells. They are the foundations for a complex biological community. The oysters are food items for juvenile blue crabs, mud crabs, and larval gobies and blennies. Many recreationally valuable fishes depend on the oyster reefs as feeding grounds and nursery areas. Oyster reef restoration efforts using natural materials mimicing the historic structures that evolved in the Bay directly complement efforts to restore and manage recreationally valuable pelagic fishes. If natural reef habitats continue to be built, the associated species (fishes, crabs) will develop and thrive in the presence of necessary habitat.

Restoration sites

Palace Bar Reef, Piankatank River (Figure 1) was built in the Piankatank River in 1993. These pictures of reef construction are provided courtesy of Dr. James Wesson, Virginia Marine Resources Commission Shellfish Conservation Division and are used with his permission. Barges brought loads of clean oyster shell to the site (a footprint of a natural reef ; Figure 2). Shells were washed overboard with high pressure hoses (Figures 3, 4, 5). The mounds of the finished product are clearly visible at low tide (Figures 6 and 7).

Related research programs

In general, the research programs that parallel our restoration efforts examine the oyster communities at the restoration site post- reef construction as well as the secondary residents and users of the reef habitat. To accurately evaluate the success or failure of a restoration effort, one must examine the ecological function of the reef in relation to natural habitats across various spatial and temporal scales. Research on Shell Bar Reef in the Great Wicomico River during 1997 examined the reef's influence on local oyster populations (Figure 1). Palace Bar Reef in the Piankatank River was the site for initial investigations on oyster colonization of a restored reef and continues to be the focus for studies examining reef community development and ecological function.

Since 2003, we have been active participants in the Native Oyster Restoration Monitoring Program (NORM) with colleagues from VIMS, VMRC, NOAA/CBO, and the U.S. Army Corps of Engineers at sites in Virginia.

Restoration partners and sponsors

All of our oyster reef restoration activities have been done in collaboration with the Virginia Marine Resources Commission Shellfish Replenishment Program under the direction of Dr. James Wesson. Program sponsors to date also include:

• Virginia Department of Environmental Quality
• U.S. E.P.A. Chesapeake Bay Program