Sarah Osorio, an 18-year-old resident of a South China Sea coral outcrop, was crowned beauty queen of the Philippines’ Palawan province after she backed her country’s claims in the disputed waters.

The win shows the popular appeal of the contest for control of the Spratlys that has sparked rising tensions between China, the Philippines and Vietnam, all vying for untapped oil reserves made more lucrative by the 24 percent jump in crude prices in the past year. The growing nationalism over the South China Sea islands has seen anti-China protests in Vietnam and Chinese gunboats firing at Philippine trawlers.

Osorio said at last week’s pageant she wanted to defend her home islands against aggression by neighboring countries. Her speech touched “the main issue right now,” setting her apart from her rivals, said Rem Divino, one of the judges.

Her victory also illustrates how governments use civilians to stake their claims to the dozens of islands, reefs and banks that make up the Spratlys — and with them rights to surrounding seabed and any oil that’s trapped beneath it. Communities on islands are a way of asserting jurisdiction, analyst Earl Parreno said.

“There are many ways of letting everybody know your stake without flexing military muscle,” said Parreno, a fellow at the Institute for Political and Electoral Reform in Manila. “They put up structures, they haul people to the islands. Some of these islands are basically uninhabitable. These are artificial communities.”

China’s Claims

China’s claims to the South China Sea extend more than 1,000 miles south from Hainan Island. Malaysia, Taiwan and Brunei also have overlapping claims.

Secretary of State Hillary Clinton last week reaffirmed U.S. commitment to defend its Philippine treaty ally, while China June 28 said disputes in the area were a matter for the countries involved.

“I’ve heard stories from my relatives of fishermen being harassed by the Chinese,” Osorio said in a telephone interview. “They don’t have the right to do that. We own Kalayaan,” as the Spratlys are known locally.

The Philippine Navy said this month it removed territorial markers placed by China on reefs near Palawan in May. Beijing- based China Mobile Ltd., the nation’s biggest phone company, last month said it had extended cellular services to cover the Spratlys, which are known as Nansha and are deemed part of Hainan province.

Taiwan-occupied Dongsha islands, known internationally as the Pratas group, share the same zip code as the city of Kaohsiung, more than 400 kilometers east.

Solar, Soil

Vietnam has installed wind turbines and built roads and reservoirs on islands it occupies in the Spratlys, and this month announced plans to develop a marine tourism industry there. Soil is shipped in to grow food, according to state-run Vietnam News Agency.

Vietnam’s claim to the Spratlys dates back centuries, according to a government document. Still, the first recorded Vietnamese child to be born there was in 2009, Vietnamplus said.

China’s rising naval power has rattled its Asian neighbors, giving an opening for the U.S. to tighten military ties with allies such as South Korea, Japan and the Philippines, and forge new relations with former foe Vietnam. The U.S. began drills with the Philippines this week off Palawan and will carry out exercises with Vietnam next month.

Jigsaw Puzzle

Efforts by China, Vietnam and the Philippines to inhabit the islands are an attempt to prove they have occupied and demonstrated control over them to improve their legal claim, said Mark J. Valencia, a maritime lawyer and senior research fellow with the National Bureau of Asian Research, said by phone from Honolulu.

Part of the problem is “you have to also show that at the time, or for a good period of the time, there was no protest by the other parties,” Valencia said. “That’s certainly not the case here over the last two to three decades.”

Sorting out the territorial claims “would become the most complex jigsaw puzzle on earth,” he said.

The Philippines, China, Vietnam, Malaysia and Taiwan have troops stationed on the Spratlys. The islands and reefs cover 5 square kilometers of land, 1 1/2 times the size of New York’s Central Park, spread over an area roughly the size of Iraq.

Chinese studies suggest the waters sit atop more than 14 times estimates of its oil reserves and 10 times those for gas.

Oil Contracts

  Philippine Energy Secretary Rene Almendras today said the government is studying whether it can offer more oil contracts in the South China Sea’s Reed Bank basin on top of the 15 oil blocks presented to investors. Reed Bank is 85 nautical miles from the Philippines and 595 nautical miles from China.

“We are staking claims to these areas because they are ours; that’s why we are offering these to investors,” Almendras said.

While the Philippine-occupied islands have around 200 registered voters, only about two dozen stay in Osorio’s home island of Pag-Asa at any one time, Palawan Governor Abraham Kahlil Mitra said by phone. Keeping people there is “of big significance that Kalayaan is part of the country,” he said.

Osorio said she stays mostly in the Palawan capital Puerto Princesa, 500 kilometers from Pag-Asa, the biggest of the occupied islands, which has an airstrip that juts out from either side. The youngest child of a municipal councilor father and accountant mother, Osorio said she stays in Pag-Asa during the summer holiday.

Protests erupted in Hanoi this month after Chinese ships cut survey cables of a Vietnam Oil & Gas Group vessel. Chinese ships in March chased away a boat working for U.K.-based Forum Energy Plc that was surveying the area. A Chinese frigate fired warning shots at Philippine trawlers on Feb. 25.

“We don’t have the capability to fight with them,” Osorio said. “The solution to the problem is diplomacy.”