The Coast Guard said about 4,000 barrels of fuel spilled in the shipping channel during the weekend after two barges collided about 12 miles from the Gulf of Mexico.
"Changing currents, winds and weather conditions have necessitated response officials to further extend containment and oil recovery plans further into the Gulf of Mexico and south along Galveston Island (off the coast of Texas,)" the Coast Guard said in a statement Sunday.
The Coast Guard said about 69,000 feet of containment boom was deployed near the incident site and another 141,000 feet was on hand if needed. Nearly two dozen response vessels were working to contain the spill and fuel from the damage barge was isolated.
The area remains closed to maritime traffic and authorities set up a containment zone Saturday in an effort to prevent the further spread of oil.
The Coast Guard said about 10 soiled birds were discovered since the incident occurred. It said there was no immediate threat to the public.
Kirby Inland Marine Corp., which owns the barge, said it was concerned by the incident and focusing on cleaning it up.