A Chinese bulk carrier stranded on the Great Barrier Reef for nine days gouged a three-kilometer scar in the coral that could take marine life decades to recover, a top expert said Tuesday.

David Wachenfeld, the chief scientist at the authority overseeing the famed marine treasure, said the Shen Neng 1 coal carrier grinded against and crushed the reef after it veered off course and smashed into it April 3.

"This is by far the largest ship-grounding scar we have seen on the Great Barrier Reef to date," Wachenfeld told broadcaster ABC. "This vessel did not make an impact in one place and rest there and then was pulled off. This scar is more in the region of three kilometers long and up to 250 meters wide."

The vessel, still carrying 68,000 tons of China-bound coal, was successfully lifted off the coral reef Monday after crews spent three days pumping heavy fuel oil from the ship to lighten it. Salvage crews later towed it to an anchorage area near Great Keppel Island, 38 nautical miles (70 kilometers) away, according to the AP.

But concerns focused Tuesday on the plight of the reef, which was also left plastered with toxic paint from the ship's hull.

Divers "have found significant scarring and coral damage. They've also found quite a lot of anti-fouling paint spread across the reef," Russell Reichelt, chairman of the marine park authority, told ABC radio. "It is a concern because it's designed to be toxic and stop things from growing on ships. We've already seen observations where anti-fouling paint that's been scraped off onto the reef is killing coral in its vicinity."

Officials have promised to investigate allegations that ships have been taking shortcuts through the world's biggest reef, which covers 344,000 square kilometers off the east coast and is a major tourist draw.

The stranded ship belongs to the Shenzhen Energy Group, a subsidiary of China's State-owned China Ocean Shipping (Group) Company.

"Make no mistake, this company will pay a very substantial price for this incident," Queensland state Transport Minister Rachel Nolan told Australian radio Tuesday. "Their ship was off course in very environmentally sensitive areas, and they will pay the price."

Conservationists say the incidents highlight the risk to Australia's environment posed by rocketing resource exports to Asia, which are fueling a strong recovery from the global financial crisis.

The reef, which is visible from space and is one of the world's foremost ecological treasures, has already come under growing threats from rising sea temperatures and pollution.

Agencies