TAURANGA, New Zealand — The calmest weather in days has given salvage crews hope they will be able on Friday to resume pumping the remaining fuel from a cargo ship stuck on a New Zealand reef.

The ship Rena has already spilled hundreds of tons of oil and crews are in a race against nature to try and remove the remaining fuel before waves break up the vessel, which has begun to crack apart and is leaning on a 22-degree tilt.

Last week crews removed about 10 tons of oil before the weather forced them to postpone salvage attempts.

Environmentalists have warned of a disaster for wildlife if all the ship’s 1,870 tons of oil and 220 tons of diesel is allowed to spill into the ocean.

Nick Bohm, a spokesman for Maritime New Zealand which is managing the emergency response, told The Associated Press Friday that crews are “relatively positive” they can proceed with plans to board the vessel and begin pumping oil to a nearby barge. He said pumping should begin Friday afternoon in an operation that could last several days.

A vertical crack in the ship runs around the entire vessel — meaning the ship is now only held together by its internal components, said Steve Jones, another spokesman for Maritime New Zealand.

“The reality is the vessel could break up at any point,” Jones told The Associated Press.

There were 1,368 containers on board, 11 of which contained hazardous substances, Maritime New Zealand said. One of the hazardous containers is among those that have fallen overboard, Jones said.

Some of the contents of containers that had washed ashore were strewn across the coastline this week, including thousands of meat patties that littered the sand.

Maritime New Zealand estimates that at least 390 tons of heavy fuel oil have spilled from the hull, leading New Zealand’s environment minister, Nick Smith, to call it the country’s biggest maritime environmental disaster.

Several miles of coastline have been closed to the public, and some beaches were beginning to experience severe oiling, Jones said.

“I was down there,” this week Jones said. “It was just black coming in — just black, black, black.”

Printed on Friday, October 14, 2011 as: Oil, chemical cargo spills onto New Zealand coast