Apart from bleaching, the world's coral reef system has a new enemy: coal dust. A new study found that coal dust in seawater can destroy corals, dampen the growth rate of fish species and seagrass.
The findings led experts to suggest that a major shipping incident can pose great dangers to the Great Barrier Reef in Australia.
The corals highly exposed to the coal dust died in just two weeks. The ones who were exposed to lower levels survived a bit longer, but the majority died off after a month of exposure, added Kathryn Berry, the study's first author from James Cook University.
The fish and seagrass did not only die due to exposure, but the researchers noted that their growth also slowed down by half.
These observations were compared directly with the ones exposed to clean water. The controlled experiments were conducted at the Australian Institute of Marine Science's National Sea Simulator.
Apart from shipping incidents, coal dust is introduced into the seawater through storage and loading activities. In 2013, the MV Smart was transporting more than 140,000 tonnes (154,000 tons) of coal in South Africa when disaster struck.
The 2010 Great Barrier Reef oil spill caused by the Shen Neng 1 ship left what is said to be the "largest grounding scar" on the iconic reef to date. Several areas were so damaged that no marine life survived and grew ever since. After the incident, the ship still navigated the area while carrying 60,000 tonnes (66,000 tons) of coal.
Even though there is a slim chance of another major spill on seagrass meadows and coral reef systems, the consequences of such events are now being researched said study author Dr. Andrew Negri.
The authors hoped that the new findings will provide information to Australia's coal shipping management companies as well as those around the world.
The research can help in identifying the risks linked to coal dust exposure as well as the marine species that could be greatly affected.
The research was published in the journal Scientific Reports on May 13.
