Oysters in Virginia
After hatching, young Eastern oysters (Crassostrea virginica) float until settling on a hard surface on the bottom of the saline portions of the bay. Oyster bars have expanded, generation by generation, as young oysters settled on the shell of older oysters that had found a hard spot on a river bottom or at the edge of the bay/ocean.
By one estimate, the water level in the Chesapeake Bay rose 10mm/year as sea level rose and the bay formed between 7,400 and 8,200 years ago. Oysters are able to increase the height of their reefs by that amount annually. The size and extent of oyster reefs in the bay 400 years ago may have been determined by the available food in the water. The oysters were once so plentiful, and so efficient at filtering food, that the species filled its biological niche and there was no opportunity to expand further. Oysters can not live in fresh water and can not survive on a bottom of mud or shifting sand, but at one time all the habitat was occupied. The Chesapeake Bay was "full" with oysters 400 years ago.1
The word "Chesapeake" may not be Algonquian for "great shellfish bay" despite years of traditional references to the meaning of that name,2 but idea behind that translation is appropriate. Native Americans created great mounds ("middens") of leftover oyster shells, after feeding heavily upon oysters for centuries.
That harvest, with technology no greater than a stick or antler to break oysters free, did not destroy the oyster bars in the Chesapeake Bay, or the saltwater portions of Tidewater rivers, or on the Atlantic Ocean edge of the Eastern Shore. When John Smith sailed/rowed around the bay and its tributaries in 1608, his men struggled to get their shallop across shallow reefs of oysters exposed at low water.
- Early English settlers were also able to harvest oysters in great quantities without reducing the ability of the species to recover. In 1686, Durand de Dauphine noted that his host had no difficulty obtaining several hundred pounds of oysters on short notice:3
- "He had only to send one of his servants in one of the small boats & two hours after ebb-tide he brought it back full. These boats, made of a single tree hollowed in the middle, can hold as many as fourteen people & twenty-five hundredweight of merchandise."
Now oysters have fallen upon hard times in Virginia, due to overharvesting, pollution, and disease. Those ancient reefs have been flattened and excavated by "tonging" with double-sided rakes to dig oysters by hand, and by "dredging" to strip mine the oysters from a reef, using wind- or motor-powered boats to drag a cage with a hard edge that rips oysters free.
- As the oyster shells were mined (ground up and used as grit in chicken feed, for fertilizer, or for road construction), the reefs disappeared. At Wreck Shoal in the James River, 4-6 feet of oysters have been removed. As reported by the Virginia Institute of Marine Sciences:4
- “Oysters have in the course of their long evolutionary period evolved as reef animals... Prior to 1880 good oyster rocks (bottoms) were common in the York River. They were the results of generation after generation of oyster shells settling on top of the previous crop, until finally the “oyster bars” were exposed at low tide. Those the results of natural conditions, but not for long.”
- “By 1900 the oystermen had tonged up most of the oysters and had failed to return any appreciable amount of the shells. They sold the shells as well as the meats. The shells were ground and sold as chicken grit or burned into lime.”
- “No better proof of this lowering or even total removal of the oyster rocks can be presented than the examination and comparison of a York River Coast and Geodetic Chart of 1858 with a recent one. 'Bare at low water' is the notation on the 1858 chart at Pages Rock Lighthouse. Today the reading at the same spot
shows a depth of three feet and the bottom is soft mud.”
Pages Rock Lighthouse, near modern-day Cheatham Annex of Yorktown Naval Station, as depicted on 1906 map
Source: US Geological Survey, Williamsburg 15x15 topo map
- A 1999 report, also from the Virginia Institute of Marine Sciences, summarized the resulting impacts:5
- "Overfishing in the late 1800s and early 1900s reduced Chesapeake Bay market oyster landings from a peak of about 24 million bushels in 1887 to a more-or-less steady state of about 5 million bushels by 1930. This high harvest pressure also mined the oyster reefs themselves, greatly reducing the reef habitat in the Bay. In the last four decades two protozoan diseases (MSX disease caused by Haplosporidium nelsoni and Dermo disease caused by Perkinsus marinus) have combined to further reduce oyster populations throughout Chesapeake Bay to about 1% of historical levels.
- The biological impact of the destruction of the oyster population is significant:6
- "Oysters are filter feeders, which means that they remove nutrients from the water as they siphon it through their gill system. This filtering process removes the phytoplankton and other small organisms that grow in the water. In essence, each oyster is a small, water- treatment plant that cleans the water passing through it as it feeds. The cumulative effect of millions and millions of oysters feeding each day was to keep the waters of the Chesapeake clear and pristine. Biologists have estimated that when the English settlers reached Virginia and Maryland in the 1600s, oysters were filtering the entire Chesapeake Bay once a week. The result was waters of remarkable clarity, even down to depths of twenty feet or more."
- "Literally billions of oysters were harvested from the Chesapeake during a single century, and most of these were removed in a forty--year period- with enormous environmental repercussions. In particular, the water-filtering capacity of the Chesapeake was seriously compromised. Whereas in 1600 the water of the bay was completely filtered about once a week, a process that removed the accumulated organic materials suspended in the water, by the late 1900s the remaining oysters would require over one year to accomplish this same feat."
- "Removal of so many shellfish meant that nutrient levels would build up in the waters. This enrichment was increased even more by human activities in the twentieth century with the dumping of massive quantities of chemicals, fertilizers and other materials into the Bay waters. The result was greater biological production of tiny phytoplankton and other organisms and not enough oysters to eat them. As these creatures died and decayed, oxygen was removed from the water in greater amounts, eventually leading to the development of dead zones."
- "Evidence suggests that in the early 1900s, the Chesapeake ecology began to shift from being a body of water dominated by bottom dwelling organisms in clear water to one dominated by microscopic animals, plants, and bacteria suspended in murky water."
Overharvest of Chesapeake Bay oysters is a classic example of the "tragedy of the commons." Oysters grew on the river and bay bottoms, owned by the Commonwealth of Virginia rather than any single individual. As a result, there was no incentive for a waterman to leave any oysters behind when harvesting a reef; some other waterman would simply take the oyster before it had a chance to reproduce.
oyster with hard shell of calcium
Source: US Geological Survey Nonindigenous Aquatic Species Database, Crassostrea virginica
Virginia and Maryland did not treat reefs as a renewable resource. Instead, the states allowed watermen to mine the oyster populations in the same way that coal is mined today - scrape up the resource and haul it away.
States did not ensure enough young oysters would remain to repopulate reefs and support perpetual oyster removal, and failed to enforce various state regulations consistently. Various ineffective efforts to manage the oyster harvest included limits on dredging, reduced seasons, and prohibition of "foreign" boats - not only the Connecticut watermen who moved into the Chesapeake after overharvesting the beds in Long Island Sound, but also boats from across the state line.
Oyster wars broke out between Maryland and Virginia, as each state tried to block watermen from dredging oysters on the "wrong side" of the state boundary. The Virginia-Maryland boundary arbitration in 1877, determined by the Black and Jenkins decision, was triggered by a desire to define control of oyster beds in Tangier and Pocomoke Sounds.
In 1882 and in 1883, Virginia Governor William Cameron led nautical expeditions from Norfolk to capture illegal dredgers in the Rappahannock River, and in 1884 Virginia created a naval police force to ensure compliance with oyster regulations. The "oyster navies" of Virginia and Maryland fought with watermen and each other at times until the 1950's, when the population had collapsed.7
- Virginia did recognize there was a problem. While controls on "hunting" wild oysters were ineffective, the state did encourage "farming" of oysters. Virginia authorized individuals and companies to create new oyster reefs, where only the individual/company responsible for creating the private reef is allowed to remove oysters from that location. Today, the Virginia Marine Resources Commission (VMRC) issues the leases and ensures compliance with aquaculture regulations.
Virginia's privatization program began with identification of the remaining underwater sites where natural oyster production was sufficient to maintain interest in commercial harvest, mapped during 1892-95 in the Baylor Surveys. A policy statement for public access to those documented areas was incorporated as Article XIII, Section 175 of the 1902 Constitution of Virginia.8 That policy survives in today's state constitution as Article XI, Section 3, Natural oyster beds:
- "The natural oyster beds, rocks, and shoals in the waters of the Commonwealth shall not be leased, rented, or sold but shall be held in trust for the benefit of the people of the Commonwealth, subject to such regulations and restriction as the General Assembly may prescribe, but the General Assembly may, from time to time, define and determine such natural beds, rocks, or shoals by surveys or otherwise."
Oyster restoration efforts have rarely succeeded, though new techniques offer promise. A major problem in the past was the design of the restoration projects - soon after areas were restocked, commercial harvest was allowed. Any oysters that survived the sediment, predation by cow-nosed rays, and disease would be removed quickly, so reefs did not regrow. New projects involve creating oyster sanctuaries and taller reefs, 10-18 inches above the bottom of the river/bay. Core areas are restocked and left to gow without disturbance. Early results suggest the oysters in the sanctuary are growing, spawning, and contributing to expansion of nearby reefs. However, in 2011 Virginia officials were still resisting efforts to focus restoration on new oyster reefs that are off-limits to commercial harvesting.9
Interest in oyster aquaculture has boomed recently. Oysters are raised on shells is placed in wire cages, which may be suspended above the bottom to minimize the problems with silt coating the artificial reef. One reason for the boom is a genetically-modified variant of the Eastern oyster (Crassostrea virginica), created in response to proposals to import an Asian species (Crassostrea ariakensis). The Asian species was to be more resistant to the bay's pollution and diseases. The sterile version of the Asian species was considered, so it could not start reproducing naturally and create unexpected consequences for the ecology of the Chesapeake Bay.
A sterile "triploid" equivalent of the native species was developed for comparison. It turned out that the sterile version of the native species grows to maturity before the diseases can affect them, so commercial production of native oysters in cages is now feasible. In April, 2009, the Corps of Engineers concurred with Virginia and Maryland officials and recommended against introducing the non-native species.10
Landowners with riverfront property can get a VMRC permit to raise oysters, but neighbors are starting to complain as a few cages attached to existing docks ("oyster gardens") grow into industrial operations with expanded waterfront infrastructure. The 2011 General Assembly rejected a proposal to modify the definitions in the Right to Farm Act, to block local government from controlling aquacultural operations. The 2011 General Assembly also considered a bill to establish 15 Aquaculture Opportunity Zones on 1,000 acres of bay bottom, much of it away from the shoreline, but opposition from existing oyster farmers caused the bill to be rejected.11
In 2012, a report to the General Assembly concluded that management of the bottomlands on the Atlantic Ocean side of the Eastern Shore should be modified. In contrast to the Chesapeake Bay, most oyster beds on the seaside of the Eastern Shore are located between the high and low tide levels, as small "fringing reefs along the edge of marshes or as patch reefs on intertidal mud and sand flats" - and not within the boundaries of the Baylor Grounds. Key findings of the report were:12
- (i) that the current boundaries of the public shellfish beds, defined largely by a survey in 1894, no longer accurately reflect the extent of the oyster beds on the seaside;
- (ii) that the majority of current natural oyster beds on the seaside lie outside of the public shellfish bed boundaries, largely on unassigned state-owned bottomlands; and
- (iii) that maximizing the benefits to public fisheries and private aquaculture, while enhancing habitat restoration and protecting natural resources will require some modifications to the current de facto zoning of state-owned bottomlands on the seaside of the Eastern Shore.
1. Roger Mann, Juliana M. Harding, Melissa J. Southworth, "Reconstructing pre-colonial oyster demographics in the Chesapeake Bay, USA," Estuarine, Coastal and Shelf Science Volume 85, Issue 2, 10 November 2009, p.221, http://www.sciencedirect.com/science/article/pii/S0370269303016769 (last checked December 3, 2011)
2. "A Dead Indian Language Is Brought Back to Life: Relic of Va. Past Re-Created for Film," Washington Post, December 12, 2006, http://www.washingtonpost.com/wp-dyn/content/article/2006/12/11/AR2006121101474.html (last checked December 3, 2011)
3. Durand de Dauphine, A Huguenot Exile in Virginia, or Voyages of a Frenchman exiled for his Religion with a description of Virginia and Maryland, Gilbert Chinard (editor), The Press of the Pioneers, New York, 1934, p. 124
4. William J. Hargis, Jr. and Dexter S. Haven, "Chesapeake Oyster Reefs, Their Importance,
Destruction and Guidelines for Restoring Them," Chapter 23 in Oyster Reef Habitat Restoration: A synopsis and Synthesis of Approaches,
Edited by M. W. Luckenbach, R. Mann and J. A. Wesson, 1999, Virginia Institute of Marine Science Press , Gloucester Point, VA, p.333 http://web.vims.edu/mollusc/pdffiles/HargisHaven.PDF (last checked December 3, 2011)
5. "Chesapeake Bay Oyster Restoration - Consensus of a Meeting of Scientific Experts," Virginia Institute of Marine Science
Wachapreague, Virginia, June 1999, p. 4, http://web.vims.edu/vimsnews/CBOysRestor.pdf (last checked December 3, 2011)
6. "Oyster History," Oystyer Company of Virginia, http://oysterva.com/oyster-history.html (last checked December 3, 2011)
7. James Tice Moore, "Gunfire on the Chesapeake: Governor Cameron and the Oyster Pirates, 1882-1885," The Virginia Magazine of History and Biography, Vol. 90, No. 3 (Jul., 1982), pp. 374, http://www.jstor.org/stable/4248570 (last checked December 3, 2011)
8. 1902 Constitution of Virginia, http://confinder.richmond.edu/admin/docs/Virginia_1902.pdf (last checked December 3, 2011)
9. David Malmquist, "Study shows taller reefs in large sanctuaries are key to oyster restoration," Virginia Institute of Marine Science, July 30, 2009, http://www.vims.edu/newsandevents/topstories/tall_reefs.php; "Virginia, Army Corps pick an oyster plan," The Virginian-Pilot, June 29, 2011, http://hamptonroads.com/2011/06/virginia-army-corps-pick-oyster-plan (last checked December 3, 2011)
10. Maryland Department of Natural Resources, "Oysters: April 2009 - Joint Decision Made to Remain Fully Committed to Native Oysters," http://www.dnr.state.md.us/dnrnews/infocus/oysters.asp (last checked February 20, 2010)
11. "Virginia oyster industry fights off aquaculture bills," Newport News Daily News, April 4, 2011, http://www.dailypress.com/news/gloucester-county/dp-nws-cp-aquaculture-two-20110404,0,1599384.story
12. "Management of State-owned Bottomlands on the Seaside of the Eastern Shore," Report Of The Virginia Institute Of Marine Science And The Virginia Marine Resource Commission (SJR 330, 2011), senate Document No. 7, 2012,
Habitats and Species of Virginia