(CNN) -- The tanks of a U.S. Navy warship stuck on a Philippine reef have been pumped full of seawater to keep the vessel stable while salvage ships make their way to the site of the grounding, officials said Monday.
Navy-led salvage teams have also removed most of the materials from the minesweeper USS Guardian that could pose environmental problems for Tubbataha Reef, a Philippine national park and UNESCO World Heritage Site. Those materials include paint, solvents and lubricants, according to a statement from the U.S. Embassy in Manila.
"We continue to place extra scrutiny on removing everything we can to mitigate possible damage to the marine environment," U.S. Navy Rear Adm. Tom Carney, the on-scene commander of the salvage operation, said in a statement.
All of the 15,000 gallons of diesel fuel aboard the 224-foot-long, 1,312-ton ship were removed Friday, the Navy said.
"An equivalent amount of seawater was pumped on her fuel tanks," Philippine Coast Guard spokesman Lt. Cmdr. Armand Balilo told the official Philippine News Agency.
Dry food stores and the personal effects of the Guardian's crew of 79 have also been removed, the Navy statement said.
The seawater pumped aboard the Guardian should keep it stable until salvage ships with heavy cranes arrive this week to begin the process of lifting the minesweeper off the reef, Balilo said.
Salvage experts have also begun to reinforce the wood-and-fiberglass hull of the minesweeper with Kevlar lines to mitigate stresses from waves hitting the vessel, the U.S. Embassy said.
The $61 million vessel was on its way from Subic Bay, Philippines, to its next port call in Indonesia when it struck the reef, about 80 miles (130 kilometers) east-southeast of Palawan Island in the Sulu Sea, on January 17.
Initial efforts to free the Avenger-class mine countermeasures ship at high tide were unsuccessful. Its crew was evacuated to other vessels, and the ship was battered by waves that pushed it farther onto the reef.
An investigation is under way to determine the cause of the grounding. A Navy spokesman, Lt. Cmdr. James Stockman, said last week that the U.S. National Geospatial-Intelligence Agency, which prepares the digital navigation charts used by the Navy, has reported the location of the reef was misplaced on a chart by nine miles.
The Tubbataha Reef is home to a vast array of sea, air and land creatures, as well as sizable lagoons and two coral islands. About 500 species of fish and 350 species of coral can be found there, as can whales, dolphins, sharks, turtles and breeding seabirds, according to UNESCO.
Philippine officials said this week that the Philippines would seek compensation for damage to the reef. About 1,000 square meters (about 10,760 square feet) of the reef have been damaged.