2017 was a very rough year for hurricanes. Parts of the Caribbean Islands, United States and Mexico were ravished by multiple hurricanes and left devastation in their path.
When hurricanes occur, especially as strong as the ones 2017 produced , damage also occurs under water. It’s often easy to overlook the damage below the waves but early investigations have revealed the extent of it in a video.
To investigate how vulnerable corals are to hurricanes, and how capable they are of recovering, a team of scientists has been exploring the reefs off the island of St John.
“In shallow waters, what we found certainly lived up to our expectations – holy moly this was bad news,” said expedition leader Dr Peter Edmunds, a biologist at California State University, Northridge.
Coral colonies were found to have had branches ripped off or having open wounds in which harmful bacteria and algae were allowed to grow. In other places, entire colonies had been swept away.
“Hurricanes generate huge waves. The effect is like sandblasting – the waves carry sand and debris, such as bits of broken coral, onto the reefs, striking them over and over again,” said Dr Howard Lasker, a geologist at the University at Buffalo.
As climate change is predicted to increase the strength of hurricanes, coral reefs will most likely see much more damage in future storms. Scientists are using the data that was collected from the damage reefs off St. John to to evaluate how reefs bounce back from heavy storms.
“It’s an interesting natural experiment,” said Dr Lasker. “You could not, in good conscience, conduct such an experiment on your own as a scientist, and it is sad to see these beautiful places in the ocean damaged so severely.”
“But we can learn from this – it gives us the chance to better understand the process of recovery,” he said.
With the potential of stronger storms to cause more damage, coral reefs today must adapt to deal with a litany of problems include coral bleaching, pollution, destructive fishing habits and invasive species.
They note that while they saw promising signs off St John, coral reefs today must deal with additional factors that could make recovery difficult.