GALVESTON — About a dozen tar balls that washed ashore on Crystal Beach were identified Monday as oil from the BP well blowout in the Gulf of Mexico, the first evidence that oil from the spill has reached the Texas coastline.

But it was unclear whether the oil from the blowout dropped off a passing ship or drifted nearly 400 miles.

Laboratory tests showed that the tar balls came from the BP Macondo well that blew out April 20, killing 11 crew members on the Deepwater Horizon drilling rig and spewing millions of gallons of oil into the Gulf, said Coast Guard Cpt. Marcus Woodring, commander of the Houston-Galveston sector.

The handful of tar balls came ashore Saturday and a second wave amounting to about 5 gallons of oil was found Sunday scattered along 1½ miles of beach on eastern Galveston Island and Crystal Beach on the Bolivar Peninsula, Woodring said. Laboratory results on the oil discovered Sunday are expected today, Woodring said.

An onslaught of tar balls on Galveston’s beaches would be disastrous for the island city’s tourism economy. Galveston Mayor Joe Jaworski hoped the tar balls were a one-time occurrence.

“It is such a small amount that I’m waiting to see whether more comes or not the next few days before getting really upset,” Jaworski said.

Tilman Fertitta, CEO of Landry’s Restaurants, said he’s not so worried about the tar balls because they’re a common sight in Galveston. He’ll be concerned, though, if it continues and swells into a problem like it has in other states along the Gulf Coast.

Landry’s has restaurants in Galveston, and a separate business controlled by Fertitta owns the San Luis Hotel, Hilton and IHOP restaurant there. Landry’s also owns the Kemah Boardwalk, a popular tourist spot.

Landry’s has lost millions in sales and suffered from higher seafood pricing since the spill occurred, he said, adding that the company is reviewing possible claims against BP.

Greater impact feared

The company buys much of its seafood from suppliers around the world, so it hasn’t been as heavily affected by local price jumps as others, he said. But as contracts run out, he expects to also be hit with higher prices.

“We’re suffering a huge impact now, but it will only get larger,” he said. “We hope Galveston continues to be a nonissue.”

RoShelle Gaskins, a spokeswoman for the Galveston Island Convention & Visitors Bureau, said the key is figuring out how the tar balls got on the beach. Officials said tar balls are common along the Texas coast because of natural seepage from the Gulf or from small oil spills.

The Coast Guard, as late as last week, had told the bureau that oil from the spill was not predicted to reach Galveston, Gaskins said.

The dozen tar balls found in the surf Saturday ranged from the size of a dime to a golf ball, said Richard Arnhart, oil spill response regional director for the Texas General Land Office.

A Gilchrist resident reported the tar balls Saturday, and the General Land Office received multiple reports Sunday, said Wesley McDaniel, Land Office oil response officer.

Cleanup begins

T&T Marine, a Galveston company contracted to do oil cleanup, used shovels to pick up the tar balls, Arnhart said.

Arnhart said the chances of BP oil reaching the Texas coast were between 20 percent and 40 percent.

“We are prepared for it, if it does happen,” Arnhart said. “The longer Deepwater Horizon discharges, the better chance that we will have some impact” on Texas beaches.

Woodring said the condition of the tar balls didn’t look like they had drifted all the way from the Macondo well.

They were “inconsistent with the weathering pattern that would be expected,” he said. “To travel 400 miles is going to take a long time,” during which the oil would be expected to break down.

Officials were investigating whether the tar balls were from oil that clung to the hull of a ship passing through the BP oil slick or were from ballast water taken on by a ship in the oil slick zone and later dumped in Texas waters, Woodring said.

BP spokesman Neil Geary said the company is concerned about the oil found in Crystal Beach.

“I will point out that it’s consistent with very fresh oil,” Geary said. “A potential source is under investigation.” He said BP expected to receive a bill for the cleanup and that it would be paid.

harvey.rice@chron.com

purva.patel@chron.com