The National Oceanic and Atmospheric Administration extended the boundaries of the closed fishing area in the Gulf of Mexico into the northern portion of the warm water current known as "the loop" current as a precautionary measure, the agency announced.
The closed area now represents 45,728 square miles, which is about 19 percent of Gulf of Mexico federal waters.
Though the latest analysis shows that the bulk of the oil remains dozens of miles from the loop current, according to NOAA, the new boundaries address the possibility that a tendril of light oil has entered or will enter the loop current.
The loop current is also known as the Florida current as it flows through the Florida Strait and then into the Gulf Stream as it heads north to the East Coast of the U.S. Both the location of the loop current and the location of the oil slick are dynamic.
The newly closed area is more than 150 miles from the nearest port and primarily in deep water used by pelagic longline fisheries that target highly migratory species, such as tuna and swordfish.
Coastal fisheries, such as grouper, snapper and shrimp, will not be affected by the expansion of the closed area.
"The BP oil spill is unprecedented and quickly changing. The administration's response since the beginning has been aggressive, strategic and science-based," said Jane Lubchenco, undersecretary of commerce for oceans and atmosphere and NOAA administrator, in a statement. "As we expand the fishing closed area, we are doing what science demands of us and are acting with caution to ensure the safety of the seafood Americans will put on their dinner plates."