Area environmental organizations and watermen are equally concerned about the decline of oysters in the Chesapeake Bay. Before siding with restoration or replacement proponents, consider the reasons behind the decline and the goals of restorers.
History of Oysters in the Bay
Native Americans and Europeans enjoyed oysters for thousands and hundreds of years. However, there were plenty of mammals, birds, and fish to hunt and eat. It wasn’t until the collapse of the oyster industry further north and the advent of mechanical means for harvesting oysters that pressure on the Chesapeake Bay fishery built. Stocks of oysters declined steadily as commercial harvester set upon them.
Diseases, one introduced and one native, further reduced a diminished oyster population in the late twentieth century.
Oysters as a Keystone Species
Scientists and watermen have been increasingly concerned by the decline of oysters, especially given the related loss of habitat and livelihood. Oysters and their shells form a reef habitat that nurtures other sea creatures. When mechanical harvesting equipment ripped it up, the habitat was destroyed. In addition to the many fish that used the reef as a nursery ground, the oysters themselves needed it: oyster young attaches to old shell and from there they survive and grow.
Oysters are also considered to be a key species that filters and cleans water in the Chesapeake Bay. The estuary is fed by rain and thousands of creeks and rivers that flow downhill throughout its 64,000 watershed. The Bay receives water over a broad area and the Bay bowl has an average depth of 20 to 30 feet. All of this water with its land wastes and eroded soil sloshes back and forth with the tide. The process that flushes it between the Capes of southern Virginia into the ocean is slow.
Approaches to Oyster Restoration
A number of methods have been used to rebuild oyster populations, which currently stand at one percent of the quantity estimated to have been here when Jamestown was settled in 1607.
- Shells have been returned to the Bay. In addition, substrate for oysters has also been provided by everything from sunken battleships to porcelain toilets.
- Legislation has limited the number of oysters that watermen can harvest in order to give remaining stocks time to reproduce.
- Environmental organizations like the Chesapeake Bay Foundation have championed oyster growing initiatives. When baby oysters are ready to reproduce, they are collected from thousands of oyster growers and deposited on recreated reefs. Others have proposed adding Asian oyster stocks.
Multiple Stressors
Theses popular restoration methods have not been successful by and large because of many other stresses on the ecosystem.
- More than 16 million people live in the watershed. Sewage and toxic materials from homes and industry pollute the bay.
- Nutrients from agricultural fields and residential fertilizer cause an overabundance of algae to bloom and die, consuming the oxygen that oysters need to live.
- Silt and freshwater flow into the Bay from construction sites, pavement and roofs.
- Light cannot penetrate the murky water.
- Old and new predator species are preying on tasty young oysters.
- Remaining oysters are suffering from low reproductive success.
Ecology Versus Economics
Do Bay proponents want the oyster to be restored to its former role as a keystone species or to they want to restore the fishery? To restore to filter water and create habitat for diverse species including blue crabs and striped bass would not restore the oyster for commercial purposes. Some have argued that commercial harvesting cannot coexist with rebuilding natural reefs because oysters could not replace themselves fast enough.
Instead, it is now being proposed that portions of the Bay be set aside for private commercial aquaculture in oyster farms. Other groups and initiatives should be set to the task of restoring biodiversity and clean water. One effort will help to restore an industry while the other will contribute to public well being. These two distinct efforts can coexist.
The current challenge for both sets of restoration advocates is to help businesses and residents of the Bay area recognize that their land-based polluting activities pose the greatest current treat to restoring the Bay’s environment and its economic viability.
 |
