Coral bleaching event largest yet, possible remedy found

  • A long-nose file fish trying to find coral polys to eat. The CL Catlin Seaview Survey says filefish are completely reliant on healthy corals for food. Image credit: XL Catlin Seaview Survey
  • The same reef in same reef in American Samoa before, during, and after a coral bleaching event. Coral in the image to the right, capture after the bleaching event, have all died. Image credit: XL Catlin Seaview Survey
  • Coral in American Samoa before (left) and after bleaching. The first image was taken in December 2014 and the second in February 2015. Image credit: XL Catlin Seaview Survey
  • Fire coral before (left) and after bleaching. Image credit: XL Catlin Seaview Survey
Date:24 June 2016 Author: Nikky Knijf Tags:, , ,

The world is seeing the largest scale of coral bleaching yet that could impact on the livelihood of more than 500 million people worldwide. With global temperatures rising fast and the threat to reefs becoming greater than ever, researchers have might have discovered a way to keep coral reefs healthy.

In the past coral bleaching occurred as a seasonal event attributed to soaring temperatures and excessive sunlight, but in recent years climate change has spurred the event. Adding the current El Niño to the mix predicts a grim future for coral reefs the world over.

As ocean surface temperatures increase, coral expel the brown algae that live in symbiosis with the coral. The expelled algae then produce toxic compounds that force the coral to lose their natural colouration, turning them a whiter shade of pale. This discolouration lasts up to six weeks, at which time the coral will start regaining their colour.

Research has found that this discolouration drastically impacts the structure of fish communities that colonise reefs. Studies have found that when coral bleaching occurs the species of fish living in the reefs change. The newer species found in these reefs are much larger.

The current coral bleaching event began in 2014 and is expected to impact 38% of the world’s coral reefs.

Researchers at the ARC Centre of Excellence for Coral Reef Studies at James Cook University in Australia might have found a possible remedy to coral bleaching. The study’s lead researcher Dr Tracy Ainsworth told Australian Associated Press that beneficial microbes or “good bacteria” might be able to keep coral healthy as global warming takes hold.

“We know that lasting changes to the community of beneficial bacteria affects important aspects of the function of host organisms such as humans or corals, including their ability to withstand further stress,” she said.

To find our more about coral bleaching visit the XL Catlin Seaview Survey’s website here or click through to the ARC Centre of Excellence for Coral Reef Studies website, here.

 

Images credit: XL Catlin Seaview Survey