Tug boats have dragged two empty containers off the bow of the Rena as salvors find new ways to remove cargo from the increasingly hard-to-access wreck.

Maritime New Zealand salvage unit manager Kenny Crawford said the containers were plucked from the sea by crane after they were hauled off the deck.

The new container removal method is being used because the bow's position on the Astrolabe Reef has made it impossible for the crane ship Smit Borneo to get close enough to the portside to lift off some containers.

The bow remains wedged on the reef where the Rena grounded in October. Its stern has mostly slipped beneath the waves.


Ten containers were removed by crane yesterday in what was the first removal operation since the ship broke in two in rough seas earlier this month.

Divers were still assessing the two sections of the vessel, but conditions were difficult despite calm seas due to the darkness, sea surges and jagged steel.

Mr Crawford said the toxicity of the water in the stern was being assessed because the safety of salvors was paramount.

Small amounts of oil continue to leak from the vessel, with the amount still in pockets estimated to be in the tens of tonnes.

Latex gloves, fibre sheets and plywood were among the debris to have washed ashore today.

Container clean-up contractor Braemar Howells focussed its operations on Waihi Beach and Bowentown Heads, and teams continued to remove debris from White Island and Whale Island.

Five badly damaged containers were unloaded from a barge for disposal last night, bringing to 64 the number of loose containers recovered since the vessel broke apart.

A significant number of dead birds was found yesterday and overnight, particularly in the Opotiki area, but only only one found at Rabbit Island had been oiled.

About 50 dead birds have been sent to Massey University in Palmerston North for post-mortem exams. They would check whether they died from natural causes, which was common at this time of year for juvenile penguins, or other reasons.

Oil clean-ups continued today at Mt Maunganui, Matakana, Leisure Island, Motiti Island and Waihi. A protective boom inside Maketu Estuary has been removed, but the boom at the entrance to the estuary would remain in place.