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Virginia CZM Program: 2006 Coastal Grant Project Description and Final Summary

Project Task:



Virginia Institute of Marine Science

Project Title:

Shellfish Aquaculture Suitability Model

Project Description as Proposed:

This project is intended to expand and enhance the current Aquaculture Suitability Model developed by the Center for Coastal Resources Management at the Virginia Institute of Marine Science under previous grants from the VA CZM Program.  Currently, this GIS based model uses GIS data layers to identify sites suitable for clam and oyster aquaculture based upon simple physical constraints that could be easily mapped in GIS.  The model considered bathymetry, salinity, shellfish closures, and the presence of SAV habitat as a significant shallow water use conflict.    Because of its simplicity, the model fails to be spatially discriminating and therefore is limited as a management tool.  Nevertheless, the tool provides a well-grounded and validated framework to build-upon.

This project would expand this spatial model to integrate upland zoning, existing and proposed land use, and shallow water habitat parameters where available.   Inclusion of hydrodynamic flushing characteristics is important, but will be created under a separate Section 309 grant from the VA CZM Program (FY 2006 Task 93.02). However, the model will be developed to be flexible and easily upgraded when this new dataset becomes available.  If the data becomes available before the project due date, a final and revised model run will be performed.  

This project will generate the necessary digital zoning data for 3 selected localities and integrate existing land use and shallow water habitat parameters that propose potential conflicts with aquaculture operations.   This will require coordination with county land use professionals and acquisition of zoning maps in any reasonable format.  The Comprehensive Coastal Inventory Program will perform all digital data development, programming, and product delivery.

The project will be advised through a steering committee of scientists, managers, and industry professionals.  This committee is intended to review and comment on suggested model inputs put forth by the Center for Coastal Resources Management.  Based on the available data, the committee will also assist with the classification of waters of the Commonwealth with respect to shellfish aquaculture suitability.  

The Comprehensive Coastal Inventory Program will develop maps illustrating the final classification of aquaculture suitability; i.e. the model output.   The program will update existing web-based map services that currently display the existing suitability model.  A project website will be hosted by the Center for Coastal Resources Management to post the model output as maps, and provide documentation (in .pdf format) regarding the model development and content.  The model output and metadata on model development and documentation will be delivered to the Virginia Coastal Zone Management Program as shape files and non-spatial data for integration into Coastal GEMS.

The expansion of the Shellfish Aquaculture Suitability Model will provide information essential for addressing many policy and management challenges now facing the Commonwealth.  Aquaculture is a complex economic, environmental, and land resource issue with which the Commonwealth agencies and offices are currently struggling.  This proposed effort will provide maps and data that will fortify the decision making process and provide a scientific basis on which decisions can be based.

Federal Funding:


Project Contact:

Marcia Berman; (804) 684-7188;

Project Status:

10/1/2006 - 9/30/2007; Project Completed

Final Product Received:

Shellfish Aquaculture Vulnerability Model Final Report (PDF)

Project Summary Provided by Grantee:

This study uses Geographic Information Systems (GIS) to model risks to shellfish aquaculture in Gloucester, Accomack and Northampton Counties.  The model first considers basic physical and biological conditions necessary for aquaculture success and builds off an earlier effort that considered water depth, salinity, shellfish condemnation areas, and the presence of submerged aquatic vegetation.  In this iteration the model was revised to account for the impacts that current land use and proposed local zoning has on suitable growing areas.  The study uses data available from federal, state, and local government sources to derive salinity, bathymetry, submerged aquatic vegetation (SAV) distribution, water quality, land use, and local zoning.  A vulnerability index is scaled to reflect current and projected conditions and the resulting impact to shellfish growing.  

Processing for the aquaculture models took place using ArcInfo Workstation version 9.2.  The final data sets illustrate the model output for Gloucester County and the Eastern Shore of Virginia.  These areas were selected for their active shellfish growing operations.  For each region, the shallow water (<2 meters) environment is ranked according to 5 levels of risk; risk level = 0 to risk level = 4.  A risk level = 0 indicates no current or impending threats exist.  Risk level = 1 indicates there is minimal risk to aquaculture.  Risk level = 2 indicates there are existing water quality concerns.  These are based on current land use within the designated buffers.  Risk level = 3 indicates that local government zoning, if implemented could increase the risk to future or existing aquaculture.  Finally, risk level 4 indicates that significant ecological conflicts are present.  This includes presence of submerged aquatic vegetation, salinity values are < 7 ppt or 15 ppt (for oysters and clams, respectively), or shellfishing is “prohibited” by the Virginia Department of Health’s Division of Shellfish Sanitation.

Final products include a set of easy to understand maps and GIS shape files which will be integrated into the VA Coastal Zone Management Program’s “Coastal GEMS” site.  VIMS has also established a dedicated website for the project.  

Disclaimer: This project summary provides the federal dollars initially awarded to the grantee. Due to underexpenditure or reprogramming of grant funds, this figure may change. For more information on the allocation of coastal grant funds, please contact Laura McKay, Virginia Coastal Program Manager, at 804.698.4323 or

A more detailed Scope of Work for this project is available. Please direct your request for a copy


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Virginia Department of
Environmental Quality
P.O. Box 1105
Richmond, VA 23218
(804) 698-4000

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