(Updates that channel re-opened to some barge traffic)
HOUSTON, March 25 (Reuters) - The Houston Ship Channel, a waterway for carrying more than one-tenth of U.S. oil refining capacity, opened on Tuesday to limited barge traffic after being shut for three days following an oil spill, the Coast Guard said.
About 100 big tankers waited to move in or out of the waterway.
The Coast Guard said planes started flying the first of three flights over the affected area across Galveston Bay to determine the location of the spill of 4,000 barrels, or 168,000 gallons (636,000 liters), of heavy fuel oil after an oil barge and a cargo ship collided on Saturday.
Coast Guard Capt. Brian Penoyer, commander of the cleanup, has called the spill "significant." The Galveston Bay spill is far smaller than the 260,000 barrels, or 11 million gallons, of crude oil that was released when the Exxon Valdez struck a reef in Prince William Sound in 1989.
The Coast Guard also prepared decontamination and inspection stations for ships entering and exiting the channel once it reopens.
As of Tuesday morning, 54 big tankers, also known as deep-draft ships, waited to enter the channel headed to the port of Houston, while 47 waited to leave, according to the Coast Guard.
Another four ships waited to sail to Texas City, Texas, where refineries and petrochemical plants are also located. One ship was waiting to exit Texas City. Five ships were also waiting to sail to Galveston.
On a typical day, 60 to 80 large vessels, including tankers, freighters, containers and cruise ships, and 300 to 400 tugs and barges move through the channel, according to Penoyer.
Since the channel was shut, the nation's second largest refinery, Exxon Mobil Corp's 560,500-barrel-per-day (bpd) facility in Baytown, Texas, on the east side of Houston, has had to cut production.
The Kirby Inland Marine barge, which partially sank after the collision, was emptied of all remaining fuel oil and refloated by Monday, according to Kirby Inland Marine.
A total of 27 ships were collecting heavy fuel oil from the bay. Some of the oil has been pushed by north winds into the Gulf of Mexico, the Coast Guard said. The oil has also been washing ashore.
U.S. and Texas wildlife officials said late Monday that eight birds were confirmed dead from the oil spill. Seven birds that were covered with oil have been captured for cleaning, and another eight birds were observed covered with oil, but have not been captured.
(Reporting by Erwin Seba and Kristen Hays; Editing by Jeffrey Benkoe)