Over the last 27 years, corals have suffered from an increase in storms, bleaching events, and population explosions of the crown-of-thornsstarfish. The researchers note that if carbon dioxide emissions are reduced and the crown-of-thorns starfish population is brought under control, the reef has the potential to recover.
Breakdown of the loss:
- Tropical cyclones = 48%
- Predation by crown-of-thorns = 42%
- Bleaching = 10%
The study was based on over 2,000 surveys taken between 1985 and 2012 of 214 reefs. The researchers found that two thirds of the total loss occurred since 1998, and the rate of disappearance is increasing. The average rate during the 27-year period was 0.53 percent a year and now it is up to 1.45 percent.
Peter Doherty, a research fellow at AIMS explained, “If the trend continued, coral cover could halve again by 2022.”
The researchers wrote that without cyclones, crown-of-thorns starfish, or bleaching, the Great Barrier Reef could regrow at a rate of 2.85 percent a year.
“We can’t stop the storms but, perhaps we can stop the starfish. If we can, then the Reef will have more opportunity to adapt to the challenges of rising sea temperatures and ocean acidification,” said John Gunn, CEO of AIMS.
To learn more:
- Read the full story from AIMS: The Great Barrier Reef has lost half of its coral in the last 27 years
- Find the results, published in PNAS, on Monday (Oct 1): The 27–year decline of coral cover on the Great Barrier Reef and its causes
- Find out how the Great Barrier Reef is Changing in other ways
- Check out the following short video from The Guardian of some great underwater footage of the Great Barrier Reef
Copyright © 2012 by Marine Science Today, a publication of Marine Science Today LLC.