The world was rocked by late April headlines announcing the massive and devastating bleaching of large sections of the Great Barrier Reef, an iconic dive destination and World Heritage site. Australia’s National Coral Bleaching Task Force conducted an aerial survey of 2,500 miles of the reef and found 93 percent showed evidence of bleaching.
In the northern regions of the reef, most of the reefs showed severe bleaching, which effectively means that most of this area could possibly die and disappear.
Corals get their brilliant colors from the tiny algae called zooxanthella that live in their tissues. The algae and the corals have a symbiotic relationship — the algae provides food to the corals via their photosynthesis process and the algae has a place to live.
Corals have a very narrow temperature range in which they can live. If the water gets too cold or too warm, the corals become stressed. They expel the algae, so now they appear white, hence the term “bleaching.” The corals cannot live without the algae for long, so if they can’t reabsorb the algae, they eventually die.
In this video taken by the task force, the bleaching is shockingly obvious. Large, white splotches appear all along the reef system, which all used to be colorful coral.
The group of Australian coral reef and climate change researchers involved in the survey are blaming the unusually warm March sea temperatures of the Coral Sea region. They reported that there were new record highs for the month of March, with water temps more than 1-degree Celsius above average for the same period over previous years.
One of the most alarming aspects of the analysis according to many scientists was the cause for the warmer water temps. The analysis, which was led by Andrew King of the University of Melbourne, determined that the sole contributing factor was global climate change.
Using climate model simulations that didn’t factor in greenhouse gases caused by human activity, the researchers found that it would have been incredibly unlikely seas would have warmed that quickly.
Once they factored in human-caused greenhouse gases, the models found that the warming event was far more likely to occur.
“Human-caused climate change made the extreme ocean temperatures that led to the massive bleaching events along the Great Barrier Reef this year at least 175 times more likely,” reported the analysis.
The study was released without peer review — an unusual move that was attributed to the urgent nature of the findings — although climate-oriented scientists around the globe agree with the findings and have not found much cause to refute them.
If the trend continues, researches warned, every year could potentially see the same high Coral Sea temps that were recorded in 2016, and effectively, the high temps would be considered “normal” by 2034. The Great Barrier Reef isn’t alone in its struggles. Coral reefs around the world have been experiencing similar stresses, as well as pollution, over-fishing and other human-related activity.
Reefs can recover from bleaching events, so there is hope for the Great Barrier Reef. Reefs have recovered from serious bleaching events over a period of 10 to 15 years — provided they were not repeatedly being affected by harmful actions, including regular bleaching. In 2005, the reefs around Puerto Rico and the U.S. Virgin Islands lost almost half of its coral due to too-warm waters, but have begun to recover.
Several organizations around the globe are working to save our coral reefs. NOAA (National Oceanic and Atmospheric Administration) offers some lifestyle choices you can make to help. You can also check out the Coral Reef Alliance, one of the only international organizations dedicated to protecting coral reefs. They provide education, tools and inspiration to local communities to protect their reefs.
Are you concerned about the health and future of our coral reefs? Let us know your thoughts in the comments section below.
Image attribution: https://www.flickr.com/photos/oregonstateuniversity/