The wind and waves that pushed a sludgy mess out of Galveston Bay have deposited sticky clumps of decayed oil on one of the most pristine places along the Texas coast.

The Texas General Land Office on Thursday reported that oil from a punctured barge had fouled at least 12 miles of Matagorda Island, an uninhabited sliver of land favored by migratory birds, deer, alligators and other wildlife.

The news was not a surprise. For days, state and federal authorities predicted the oil might reach the barrier island, some 80 miles southwest of where the barge spilled approximately 170,000 gallons of bunker fuel Saturday.

Even with the heavy oil on the beach, officials expressed relief because it bypassed Matagorda Bay, an ecological wonder that produces a bounty of fish. Spotters said tar balls made landfall more than 10 miles south of Pass Cavallo, an inlet that separates the bay from the Gulf of Mexico.

"We dodged the bullet," said Doug Matthes, who leads Matagorda County's emergency management office.

Containing the spill

To prepare for the oil's arrival, the Coast Guard and General Land Office moved more than 200 people and 20 vessels to Port O'Connor, a village on the bay's southwest edge.

Teams deployed nearly 100,000 feet of floating boom, which is designed to trap oil on the surface before it could infiltrate fragile marshes and the bay. Officials said it was important to keep the oil out of the marshes, which shelter shrimp, crabs and fish and are more difficult to clean than beaches.

"The (forecast) models worked well, and we sent resources to the right place," said Jim Suydam, a spokesman for the Texas General Land Office, which is responsible for the state's coastline.

The robust effort reflected Matagorda Island's standing as one of the state's great natural locales. The 50-mile-long barrier island is home to about 20 species receiving special protections under state and federal law. They include the piping plover, peregrine falcon and whooping crane.

"Any impact there will be very high because it's a largely undisturbed area," said Jorge Brenner, a Corpus Christi-based marine scientist for the Nature Conservancy. "That makes it a really bad target."

Grim toll on birds

The oil has not caused severe damage onshore. Officials said at least 37 oiled birds have died in and around Galveston Bay; there were no reports of wildlife affected by the black goo near Matagorda Bay. But scientists say it could take years to understand the ecological toll of the spill.

As crews worked for a fifth day to remove what's left of the mess from Galveston Bay, pilots made progress toward returning the Houston Ship Channel to normal operations.

A backlog of 29 ships had disappeared from the Port of Houston by late Thursday, while about 40 inbound vessels were waiting in the Gulf for entry, said Capt. Clint Winegar, vice president of the Houston Pilots.

"We're just trying to move ships as fast and as safe as we can, trying to get everything caught up, trying to get business back as usual," Winegar said.

The port, one of the nation's busiest, returned Thursday to around-the-clock operations after two days with a shortened schedule. But Winegar said fog could force pilots to close the waterway to traffic Thursday evening, a common occurrence in the spring.

Kiah Collier contributed to this report.