Damage to reef far from over
WITH 150 tonnes of fuel oil from the stranded coal carrier Shen Neng 1 in danger of washing onto the Queensland coastline if the salvage mission goes wrong, a Southern Cross University researcher fears damage to the Great Barrier Reef is far from over.
Professor Peter Harrison, director of marine studies at the SCU Whale Research Centre and SCU Coral Reef Research Centre, has been studying coral reefs for more than 30 years and said that so far there had been only a ‘relatively small amount’ of oil spilled from the ship.
“Hopefully there will only be a minor impact on the coral,” he said. “There has been a very fortunate coincidence of calm weather, so they will be able to use floating booms. If there was a cyclone, or the ship was a large oil tanker, it could have been a major catastrophe.”
While coral near Douglas Shoal has been physically damaged by the force of the coal carrier crashing into it, and it is coated in oil leaking from the ship’s fuel tanks, Prof Harrison said the mixture of oil and the dispersants used to break up any oil slick works ‘synergistically’ to harm the coral.
“The oil contains a complex mixture of chemicals toxic to coral and marine life on the reef. The dispersant, a sort of detergent, is also toxic to coral, especially when you get overspray, which is when there is more dispersant used than is needed to break up the oil,” he said.
“They used chemical dispersants as an emergency measure to remove the slick, but this increases the amount of oil in the water.
“What they’re going to do next is place booms around the ship, and that’s the best possible way to deal with moderately-sized oil spills.”
Prof Harrison said the oil and dispersants initially caused a stress response in coral similar to bleaching.
“Stress responses occur when the coral encounters toxic chemicals in oil and dispersants, where the coral releases mucus to protect themselves from pollutants, and begin to lose the symbiotic algae providing them with energy to grow and reproduce,” he said.
However, he warned there long-term effects on coral growth and reproduction.
“The oil is also toxic to coral eggs and spawn, and both oil and dispersants reduce reproduction,” he said.
“There will be inhibition during mass spawning in November.”
Prof Harrison said while ships were legally able to travel in the vicinity of where the carrier ran aground, the incident was a warning to re-examine the need for locally-trained pilots to be aboard large vessels travelling near the Great Barrier Reef.