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By Terry Wade
TEXAS CITY, Texas, March 22 (Reuters) - Four skimming boats surrounded a partially submerged barge on Sunday at the entrance to the Houston Ship Channel, working to clean up fuel spilled from one of the vessel's tanks into Galveston Bay after a Saturday collision with a cargo ship, according to a Reuters eyewitness.
"This is a very significant discharge," said Coast Guard Lieutenant Junior Grade Kristopher Kidd, a spokesman for the maritime safety agency.
The barge contains 168,000 gallons (636,000 liters) of fuel oil, but it was not immediately clear how much fuel spilled out of the single breached tank. Several other tanks were believed to be undamaged, according to a Coast Guard statement.
The Houston Ship Channel remained shut on Sunday to contain the environmental damage and prevent additional collisions, according to the Coast Guard.
Eight refineries accounting for nearly 12 percent of U.S. refining capacity are cut off from crude oil tankers as the 53-mile (85-kilometer) waterway linking the busiest U.S. petrochemcial port to the Gulf of Mexico remains shut.
None of the refineries replied to requests for comment on how production was or may be affected due to the channel's closure.
A local official said the channel was expected to be shut for all of Sunday and possibly Monday. The official asked not to identified as the information had not yet been made public.
Also affected is shipping along the Intracoastal Waterway where it intersects the Ship Channel.
Carnival Corp's Carnival Magic cruise liner was delayed on Sunday from returning to Port of Galveston due to the spill, according to a Carnival spokesman.
The Carnival Magic has supplies of food and water aboard for the guests, Carnival spokesman Vance Gulliksen said. The Carnival Magic was due to leave Galveston on Sunday afternoon.
Another Carnival ship, Carnival Triumph, was scheduled to arrive in Galveston on Monday.
This is a far smaller spill than that by the Exxon Valdez tanker, which struck a reef in Prince William Sound, Alaska, in 1989.
A total of 11 million gallons of heavy black crude oil were estimated to have been released by the Exxon Valdez.
In contrast, only one tank on the barge was ripped open by the collision with the cargo ship in the Houston Channel on Saturday. Also, the fuel oil being released is closer in consistency to diesel fuel than the heavy, black crude oil spilled by the Exxon Valdez.
Wildlife Response Services, a Texas-based wildlife rehabilitation service, is helping affected birds and marine life. The service has not said how many animals have been received for cleaning.
In addition to four skimming vessels working on the spill, another 20 response vessels were standing by to help with the cleanup on Sunday, the Coast Guard said. About 90,000 feet of boom were staged along the Texas City dike for containment deployment.
Emergency response crews have also laid down floating barriers in hopes of containing the spill. (Reporting by Terry Wade in Texas City, Erwin Seba in Houston, Kevin Murphy in Kansas City, Mo., Alex Dobuzinskis in Los Angeles and Chris Michaud in New York; Editing by Edith Honan, Cynthia Osterman and Jan Paschal)