Oysters are important to many marine ecosystems, especially the Gulf of Mexico. These incredible bivalves filter water as they feed and “breath” the water. They are also an important commodity in the food web, especially for human consumption. The most common oyster in the Gulf is the Eastern Oyster (Crassostrea virginica), which lives in shallow estuarine habitats. According to the U.S. Environmental Protection Agency, the Gulf of Mexico led in “production of oysters in 2008 with 20.6 million pounds of meats valued at $60.2 million and representing 59% of the national total.”[1] Louisiana well exceeds production of oysters compared to other nearby states:[2]

Louisiana 12,778,311 pounds $38.8 million
Texas 2,679,207 pounds $8.83 million
Mississippi 2,610,349 pounds $6.87 million
West Florida 2,501,475 pounds $5.47 million
Alabama 72,776 pounds $243,414

The Deepwater Horizon oil spill occurred closest to Louisiana just south of the Mississippi Delta. On April 25, 2010, in an effort to keep the oil spill away from the shoreline, two large water diversion structures at Caernarvon and Davis Pond where opened to release large amounts of freshwater into Louisiana coastal areas. In mid-July, the Associated Press reported that the resulting large volume of freshwater flushing into the ocean was to blame for extensive oyster deaths.[3] Eastern Oysters are adapted to brackish (low salinity) waters, but cannot tolerate large amounts of freshwater. Furthermore, oysters reproduce in the summer, normally at the end of June when the waters are warmest. Any larvae that come in contact with oil or oil dispersants will likely die. Oyster production is expected to be very low this year, and perhaps following years, as a result of these contributing factors.

Eastern Oyster

Eastern Oyster

Resources on oysters

[1] General Facts about the Gulf of Mexico

[2] Fish Stocks in the Gulf of Mexico (NOAA)

[3] Widespread oyster deaths found on Louisiana reefs