Grounded cargo ship Rena breaks separate on NZ reef

Jan. 8, 2012, nautical naval New Zealand, the cargo ship Rena, grounded off Tauranga Harbor, New Zealand, is seen split into two pieces after being lashed by pounding seas

The Greek-owned Rena ran aground on Astrolabe Reef 22 kilometers from Tauranga Harbor on North Island on Oct. 5, 2011, spewing a heavy loaded fuel oil into the seas, fouling pristine beaches and killing up to 20,000 sea birds in what has been described as New Zealand's worst nautical naval environmental disaster.

A cargo ship grounded off the New Zealand coast since October has split in two, spilling sea containers and debris and sparking fears of a fresh oil spill, maritime officials said Sunday.

The wreck of the Greek-owned Rena was described as New Zealand's worst maritime environmental disaster even before the rear section of the ship, lashed by pounding seas, broke away overnight. The ship previously spilled heavy fuel oil that fouled pristine North Island beaches and killed up to 20,000 seabirds, and despite salvage efforts nearly 400 tons of oil remains onboard.

Officials said up to 300 of the roughly 880 containers that had been on board were lost when the ship broke apart. Of those, about 30 percent had been fitted with monitoring devices and some 30 containers had already been located.

Oil has been seen leaking from the broken ship. Alex van Wijngaarden, on-scene commander for the national response team, said oil from the vessel could come ashore around midnight Sunday.

Environment Minister Nick Smith told reporters that the "risks for the environment are a fraction of what they were in October," though the roughly 385 tons of oil still aboard the ship is about the same amount that leaked from the vessel soon after it ran aground. Salvage crews previously removed 1,100 tons of oil from the ship.

Most of the oil is in tanks in the stern section, which could end up sinking. Some of that oil could end up dissipating in the ocean rather than washing up on beaches.

The captain and Rena's navigating officer face criminal charges of operating a ship in a dangerous or risky manner, polluting the environment and altering the ship's documents after the crash.