Melbourne: A major coal spill may harm Australia's iconic Great Barrier Reef, according to a new study which found that coal dust in seawater can quickly kill
corals and slow down the growth rate of seagrasses and fish.
Coal dust enters the marine environment at loading and storage facilities when it is blown or washed into the sea, during transport, and in rare shipping disasters.
"Corals exposed to the highest concentrations of coal dust died within two weeks," said Kathryn Berry from the James Cook University in Australia.
"Corals exposed to lower concentrations of coal lasted longer, but most of them also died after 4 weeks of exposure," said Berry, who led the experimental research. "While some fish and seagrass died from coal dust exposure, it mostly stunted their growth by half compared to clean water," she said.
The scientists exposed the marine species to fine coal particles in carefully controlled experiments within the National Sea Simulator at the Australian Institute of Marine Science and measured their responses over time. In 2013, the bulk carrier, MV Smart, broke apart in South Africa while carrying over 140,000 tonnes of coal.
In Australia, over 60,000 tonnes of coal remained on board the Shen Neng 1 when it ran aground on the Great Barrier Reef off Gladstone in 2010.
"Risks to the Great Barrier Reef posed by large coal spills depend on the probability of an accident and the potential impacts to marine life," said Andrew Negri, from the Australian Institute of Marine Science.
"While the likelihood of a major spill on a coral reef or seagrass meadow is low, we are now beginning to understand the likely consequences," Negri said.
Researchers hope the results will inform management of coal shipping activities in Australia and around the world.
"This research will allow decision makers to understand the risks to marine life to identify the species that are most vulnerable," said Mia Hoogenboom, from the ARC Centre of Excellence for Coral Reef Studies at James Cook University. The findings were published in the journal Nature Scientific Reports.
