Recovery crews yesterday refloated and sank a 145-foot ship that had been aground on a reef in the Northwest Hawaiian Islands for more than a month.

Coast Guard and private officials had hoped that the M/V Casitas could be towed from Pearl and Hermes Atoll to Ho-nolulu for repairs, but elected to have American Marine contractors take the ship about 6.9 miles northwest of the atoll and allow it to sink where it would not harm the environment.

"On behalf of all the parties involved, we are very pleased to see this operation safely completed," said Coast Guard Capt. Manson Brown, on-site coordinator for the Unified Command, made up of Coast Guard and representatives of the ship's owners. "(Our goal was) to remove the potential pollutants and extract the vessel from the reef with no human injuries and as little damage to the environment as possible.

Workers previously extracted about 33,200 gallons of fuel from the Casitas; yesterday they transferred equipment, personal gear, and about 1,850 gallons of gasoline to a barge before the ship's removal. Fifteen tons of marine debris and trash were sealed aboard the doomed ship in double-hulled compartments, but Coast Guard officials said this method of sinking vessels is not unusual.

"Given the remote location and the significance of the reef ecosystem, it was a challenge — a challenge we can now say we met," Brown said.

Pearl and Hermes is part of the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve and part of the Hawaiian Islands National Wildlife Refuge. The atoll is 1,000 miles northwest of O'ahu.

The crews pulled the ship off the reef at about 11:30 a.m., and pumped water out of the hull while it was tugged northwest to the disposal site, a spot about 7,200 feet deep.

The Casitas went aground July 2 while conducting marine debris recovery efforts under contract with the National Oceanic and Atmospheric Administration.

A team of representatives from the state, NOAA and the U.S. Fish and Wildlife Service will assess damage to the atoll's reef.