A ban on fishing in federal waters of the Gulf of Mexico has been estended to an area south of Vermilion Bay, La., roughly the western edge of oil spreading from the broken BP well.

The National Oceanic and Atmospheric Administration said the closing brings to more than 81,000 square miles of federal Gulf waters closed to fishing, or about one-third of the Gulf.

It was the first federal closing since June 28 though some state waters have been periodically closed or reopened to fishing.

The Gulf is a major source of finfish and shellfish for U.S. consumers. NOAA said more than 1 billion pounds of seafood was commercially harvested in 2008, the latest period for which figures are available.