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Restoration Siting Protocol for Future Reef Construction As of September 2002, there were 50 completed oyster restoration projects in the Virginia portion of the Chesapeake Bay. Considerable interest in future construction warrants the development of a technique that allows the advanced identification of potential building sites based on best professional judgement and existing data. The locations of potential restoration sites available for future projects were sited based on conditions which could be mapped using geographic information systems (GIS) and available GIS data. This protocol considers three basic criteria. These criteria were analyzed using a hierarchical approach that combines available digital data and GIS programming techniques. The resultant maps illustrate only the endpoints of these analyses along with ancillary supporting data. This protocol first assumes that public oyster grounds will be available for all projects sponsored by federal, state, or local programs. Therefore, the Baylor grounds (public oyster grounds) provide the state owned bottom on which restoration sites would be constructed. This does not exclude privately leased bottom as potential sites, however, they are not considered as part of these analyses. Second, it is preferred that oyster reef restoration sites are constructed on hard bottom, and preferably where oyster reefs once thrived. Geo-referenced bottom probe surveys were conducted by Dexter Haven of VIMS in the 1970s and Jim Wesson of VMRC in the 1990s-present provide data verifying bottom sediment type. |
These data were used to identify areas within the public oyster grounds with hard bottom composed of shell or oyster rock. The third criteria used to designate suitable sites is based on the location of existing COE maintained navigation aids and channels. These data were included in the analyses to insure that reef construction would not interfere with either navigation or maintenance of those areas. While this represents a small percentage of the total number of channels and aids in Virginia waters, data were not available for other aids or channels not maintained by the COE. No targeted reef restoration sites were found to be in the vicinity of COE aids or channels. Using the ArcMacro language (AML) developed by Environmental Systems Research Institute (ESRI) to accompany the ArcInfo software, the hierarchical model pulls from a GIS coverage representing the most recent survey of all public oyster grounds in Virginia. This coverage is maintained by VMRC. With this coverage as a basemap, a second coverage merging digital data from various sources of bottom type data was superimposed. The combination of these two coverages was analyzed to determine the bottom surface area within Baylor grounds with hard bottom substrate. This is the basis for designating a site as suitable for future reef restoration projects. A final query at the request of the COE verified that none of these sites will interfere with navigation or maintenance of either channels or navigation aids under their congressional responsibility. A GIS coverage of these features provided by the COE was used in this analysis.
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