From NOAA's Southeast Fishery Bulletin: BP Oil Spill: NOAA Modifies Commercial and Recreational Fishing Closure in the Oil-Affected Portions of the Gulf of Mexico (PDF):
Current revisions to the closure, described below, will be effective on May 28, 2010 at 6 p.m. eastern time (5 p.m. central time). All commercial and recreational fishing including catch and release is prohibited in the closed area; however, transit through the area is allowed.
The closure is 60,683 sq mi (157,169 sq km), which is about 25% of the Gulf of Mexico exclusive economic zone. The majority of federal waters in the Gulf of Mexico are open to commercial and recreational fishing.