1. Hypoxia in the Northern Gulf of Mexico- Causes and Consequences

Seasonally severe and persistent hypoxia, or low dissolved oxygen concentrations, occur on the inner to mid-Louisiana continental shelf to the west of the Mississippi River and Atchafalaya River deltas. The areal extent during mid-summer surveys of 1993- 1997 ranged from 15.800 to 18,200 km2. The shelfwide distribution in mid-summer for 1985 to 1992 averaged 8,000 to 9,000 km2. Hypoxia occurs below the pycnocline from as early as late February through early October, but is most widespread, persistent...