Virginia Coastal Zone Management - Summer/Fall 2008
Farming the water may become as common as farming the land. Above are clam farms on Virginia’s Eastern Shore.
Holding a future harvest in hand, Tom Walker, J.C.Walker Brothers Seafood, illustrates the growth rate of clams at his clam aquaculture facility on Virginia’s Eastern Shore. Below the dime, the smallest seed are 4 months old. The clams in the middle are 14 months old, while the largest clams are 3 years old.
Shellfish Aquaculture: Shifting from Wild Harvest to Farming
By Laura McKay, Virginia CZM
Since Roman times people have known they can improve on nature’s bounty by cultivating shellfish rather than simply collecting wild bivalves. There’s a fascinating article on this by Oxford scholar, R.T. Gunther (see “Learn More About” section below).
Since the time of the Powhatan nation, Virginia’s wild clams and oysters were so plentiful, one had only to wade out into shallow waters and scoop them up. Today, wild populations of these shellfish have been almost wiped out due to centuries of heavy harvesting, increasingly devastating shellfish diseases, and, as our human population explodes, severly decreased water quality.
Virginia’s watermen face the same loss watermen in many other countries faced long ago. Japan began cultivating oysters in the 1500s in Hiroshima Bay. The French have relied on cultivated oysters since the reign of Napoleon Bonaparte in the 1860s. Their oyster farms are now legendary and oysters are a mainstay of French cuisine, celebrated in art by painters such as Henri Matisse in his 1940 canvas, “Still Life with Oysters.”
Shellfish farming is not exactly new in Virginia either. You could argue that we’ve been manipulating and increasing oyster production for a very long time by enhancing parts of their life cycle. But as our wild populations of clams and oysters have declined precipitously over the past 20 years, scientists and shellfish farmers have worked to perfect cultivation of their entire life cycle from spawning (collecting egg and sperm) in the lab, to feeding larvae and veligers lab-cultured algae, raising them to a certain size in the lab and finally growing them out to market size in near shore coastal waters in cages or under nets.
This shift in how we get shellfish to market is requiring changes in our state and local laws and policies – an issue the Virginia CZM Program has been working on since 1996. Through Section 309 of the Coastal Zone Management Act, NOAA provides match-free funds for the purpose of developing new enforceable policies for 9 different coastal management issues including marine aquaculture. Virginia CZM has used these funds for the past 12 years to award more than 20 grants totaling about $870,000 to various partners to improve our marine shellfish aquaculture policies.
Use Conflict Resolution
One set of grants has focused on resolving conflicts between shellfish farming and other uses of shallow, near shore waters. The first conflict the Virginia CZM Program studied looked at seagrass restoration versus clam farming (through grants to the Virginia Institute of Marine Science). Results showed less of a conflict than perceived because seagrass must always be underwater whereas clam farmers prefer to grow their crop in the intertidal zone where mud flats are exposed at low tide.1 However, as clam farming expands and space becomes more limited, the conflict could increase unless clam farmers find economical ways to grow and harvest clams in deeper waters, beyond the areas where underwater grasses can grow.
The second conflict the Virginia CZM Program studied looked at shorebird foraging versus clam farming (through grants to VIMS and the William and Mary, Center for Conservation Biology). Again, happily, results showed not only a lack of conflict, but perhaps a benefit to shorebirds from clam farming in that shorebirds were observed to forage on small plants and animals growing on the plastic mesh used to protect clam beds from predators – a win-win situation for shorebirds and farmers.2
Finally, the Virginia CZM Program studied (through grants to VIMS and the Middle Peninsula Planning District Commission) matrices of all potential conflicts among near shore uses. VIMS reviewed uses from a state perspective and MPPDC from a local perspective – Gloucester County. The numbers of uses considered were huge. VIMS looked at 23 uses including commercial fishing uses, recreational uses and ecosystem functions as well as shellfish farming, mapped where these uses could be undertaken, analyzed conflicts, and identified potential policy options. MPPDC looked at 14 specific conflicts that were priorities in Gloucester and came up with seven recommendations for addressing them.3
Suitability and Vulnerability Models
Virginia CZM Program grants to VIMS, focusing on use conflicts, led to additional grants to refine maps of where coastal waters were optimal, suitable and unsuitable for oyster and clam farming, as well as mapping of shellfish growing waters vulnerable to degradation. Results showed that the Atlantic coast of the Eastern Shore has the largest expanses of water optimal for clam farming (map above) and there are very few areas anywhere that were deemed optimal for oyster farming. The vulnerability maps were completed for three counties: Gloucester, Accomack and Northampton (Eastern Shore shellfish aquaculture vulnerability model map below). All of these maps can be viewed on the Virginia CZM Program Coastal Gems website at http://deq.virginia.gov/coastal/coastalgems.html.
Best Management Practices
Shellfish aquaculture is generally viewed as a positive activity both economically and environmentally. Economically, on the Eastern Shore clam farming generates approximately $50 million/year. Environmentally, clam farming increases the number of filter feeders removing algae in coastal waters and clams require no “feeding” or nutrient additives. Virginia CZM also has looked at how operations might be improved even further. Through grants to VIMS and Virginia Sea Grant, the program developed voluntary best management practices and an environmental code of practice by working with scientists and industry.4 Through this effort and those of the Shorekeeper funded under the Virginia CZM Program’s Seaside Heritage Program, the problem of abandoned clam nets drifting up on shorelines has largely disappeared.
Policy Options and Economics
Since 1996, the Virginia CZM Program has awarded seven grants to the Marine Resources Commission to develop policies regarding the use of existing shellfish bottom leases to ensure they were being used; to draft legislation to provide for a 3-dimensional aquaculture leasing program; to develop criteria for siting aquaculture operations; to develop general permits and regulations for certain shellfish aquaculture activities; and to refine maps and GIS data layers of all existing and proposed aquaculture sites. All of this has culminated in the recent adoption by the commission of a new regulation that authorizes shellfish aquaculture structures that may be placed on and immediately above privately leased shellfish grounds without an individual permit from the commission.
More recently the Virginia CZM Program completed work through grants to VIMS and VA Tech to look at economic implications of alternative shellfish aquaculture management strategies. That work involved investigation of three types of policy options:5
1. Proposals to redefine or clarify the current leasing system.
2. Proposals to invest state funds in research and development for oyster and clam production.
3. Proposals to create direct economic incentives to boost commercial production.
Policy options were evaluated based on results from a survey of oyster and clam producers, a general model of oyster supply and demand that was specified in part with results from the survey, and information obtained from other sources including a bioeconomic model of oyster growth and mortality developed by Miller (2008).
In the Virginia Tech study oyster and clam growers reported that inadequate protection of water quality was one of the most important barriers to shellfish aquaculture expansion. There can be multiple sources of pollutants that can impede or prohibit shellfish farming. Fortunately DEQ’s Water Division has been working on this issue on the Eastern Shore. A technical advisory committee was created in 2008 to guide DEQ’s development of a new regulation to better protect Eastern Shore waters from point source discharges by requiring permit applicants to conduct analyses of alternatives to discharging waste into adjacent waters. That regulation is currently under executive review and is expected to be available for public comment early in 2009.
Finally, through the Virginia CZM Program’s Seaside Special Area Management Plan, we are continuing to work on ensuring proper siting and promotion of shellfish farming on the seaside of the Eastern Shore. One of the first enforceable policies being developed is by Accomack County to extend the Chesapeake Bay Preservation Act to Accomack’s Atlantic coast to better protect seaside water quality. The Board of Supervisors recently voted to adopt an Atlantic Preservation Overlay District, in part to help ensure the continued success of Accomack’s shellfish farming industry.
For More About Oyster Cultivation Around the World
History of oyster cultivation in Ancient Rome -
http://sabella.mba.ac.uk/171/01/The_oyster_culture_of_the_Ancient_Romans.pdf
History of oyster cultivation in Japan -
http://unitar.org/hiroshima/programmes/shs05/resources/SHS05_Akashige_Abstract.pdf
History of oyster cultivation in France -
http://ostrea.org/oyster_farming_history.html
1. Virginia Institute of Marine Science, “Shallow Water Resource Use Conflicts: Development of Policy Guidance for SAV vs. Aquaculture,” Virginia CZM project description web page <http://deq.virginia.gov/coastal/description/1997projects/
tsk94-97.html>
2. College of William & Mary, Center for Conservation Biology, “Shorebird/Clam Aquaculture Conflict Assessment and Portfolio of Landscape Data for Virginia Barrier Islands,” Virginia CZM project description web page <http://deq.virginia.gov/coastal/
description/2003projects/12-02-03.html>
Virginia Institute of Marine Science, “Interactions Between Clam Aquaculture and Shorebird Foraging,” Virginia CZM project description web page <http://deq.virginia.gov/coastal/description/2004projects/11-03-04.html>
3. Virginia Institute of Marine Science, “Aquaculture Management Initiative,” VIrginia CZM project description web page <http://deq.virginia.gov/coastal/description/1999projects/94-02-99.html>
Middle Peninsula Planning District Commission, “York River Use Conflicts- Issue Framing and Policy Need Identification (Phase 3),” Virginia CZM project description web page <http://deq.virginia.gov/coastal/description/2007projects/93-01.html>
4. Virginia Institute of Marine Science, “Development of an Environmental Code of Practice and Best Management
Practices for Virginia - Year 2,” Virginia CZM project description web page <http://deq.virginia.gov/coastal/description/
2007projects/92-03-07.html>
5. Virginia Tech, “Economic Implications of Promoting the Aquaculture Industry in Virginia: Alternative Management
Strategies,”Virginia CZM project description web page <http://deq.virginia.gov/coastal/description/2007projects/
92-02-07.html>