Over 20 years the trend of decline and loss has been inexorable. In 2001, and again in 2005, even warmer seas damaged many more reefs. From 2008-11, extreme summer temperatures led to major flooding and pollution in Australia which badly damaged the Great Barrier Reef.
2013 saw sea temperatures rise again and the longest global coral bleaching event on record began in 2014 with another exceptionally strong El Niño. The 2016 and 2017 mass-bleaching events may now have affected nearly two-thirds of the world’s shallow reefs.
The fear now is that natural resilience is being lost and damaged reefs will not have time to recover before the next extreme event further weakens and then kills them.
But reefs are now beset with more problems than bleaching. Just as off Florida in the 19th century, local pollution, overfishing, loss of oxygen and excess nutrient runoff have increased, and now growing acidification of the oceans is a real danger. Most organisms can withstand some stress but few can cope with this tsunami of trouble.
Continue reading: How did half of the great Florida coral reef system disappear?