Oyster reefs built by Crassostrea virginica provide habitats for numerous invertebrate and fish species (Berquist et al. 2006). The eastern oyster is also a common host of the symbiotic xanthid crab Tumidotheres (Pinnotheres) maculates (Kruczynski 1973).The human pathogen Vibrio vulnificus is also found in the tissues of some populations of Crassostrea virginica. V. vulnificus causes primary septicemia in patients with compromised immune systems. The infection occurs when the oyster are eaten raw (Tamplin and Capers 1992, Motes et al. 1998).Fishery: The total harvest of Crassostrea virginica I s approximately 22 million pounds of meat per year, making up 70% of all the oyster harvest. Less than one half of the harvesting is from cultivated populations, making a considerable impact on natural oyster reef. The harvestable size of the eastern oyster is 75 mm. In cultivated oyster beds, individuals of C. virginica will grow to 75 mm in 12 - 36 months depending upon the food supply and environmental conditions. The demand for this fishery has decreased in recent years. This has been attributed to the instance of disease associated with eating live oysters and a general change in the eating habits of the targeted market (Wallace 2001). Despite this, over-fishing has had a major negative impact on oyster reef habitats (Meyer and Townsend 2000, Wilson et al. 2005). Aquaculture: Oyster culture serves two purposes: 1) to provide enough Crassostrea virginica to meet the demand of the oyster fishery; and 2) to restore oyster reef habitats in estuaries along the eastern Atlantic coast and the Caribbean. The eastern oyster is cultured in both natural estuaries and hatcheries. In some regions, oyster clutches are seeded in estuaries considered optimal for oyster growth and reproduction. Alternatively, larvae from controlled spawning events settled on carefully treated shells in hatcheries are then placed in large mesh bags that are subsequently taken to a nursery area in natural waters. Nursery areas are chosen for optimal environmental conditions and the absence of large numbers of potential predators (Wallace 2001).Oyster culture has been successfully used in efforts to restore reefs on the coast of North Carolina. The reefs created by seeding with live oyster clutches reached the size of natural reefs in adjacent areas within one year. C. virginica spat readily settled on the created reefs within 3 months and reached harvestable size (>75 mm) within two years. In addition, invertebrate species known to be associated with C. virginica oyster reefs were found at densities equivalent to those on natural reefs within 2 years (Meyer and Townsend 2000).
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