The Great Barrier Reef in Australia is the greatest coral reef and it hosts a remarkable number of organisms, containing 400 types of coral, 1500 species of fish and 4,000 types of mollusc. According to new research, “97% of coral on a northern part of The Great Barrier Reef in Australia has died”, and this has been the worst mass bleaching event for the reef. Additionally, The Australian Institute of Marine Science (AIMS) confirmed that “the Great Barrier Reef has faced its fifth mass bleaching event in only eight years.” 

‍

What exactly is coral bleaching? Corals are a type of animal that live in groups called colonies and the colonies sometimes join together to form coral reefs. They are the home for thousands, if not millions, of other species. Coral reefs are the largest living structure on the planet, and the only living structure to be visible from space. Coral bleaching occurs when the temperature of the ocean changes, and this phenomenon can be triggered by even a 1 degree difference in the temperature of the water. Since 1901, the first 2300 feet (700 meters) of the ocean water has increased 1.5 degrees fahrenheit (16 degrees celsius). This rate of warming is 40% higher than scientists previously estimated.

‍

Coral reefs expel a microscopic marine algae called zooxanthellae that live in their tissues when under stress. This stress is caused by changing temperatures, or another phenomenon in the ocean called acidification. As a result, coral tissues become transparent and lose their signature vibrant colors, exposing their white exoskeleton underneath; called coral bleaching. The zooxanthellae produce about 90% of the food the coral needs to grow. With this algae gone, it leaves the corals vulnerable.

‍

These coral reefs can recover, but it takes decades, and the more severe the damage is, the longer it will take to recover. Scientists from the Australian Institute of Marine Science conducted research showing corals are receiving more and more damage as temperatures in the ocean increased. After looking at the results of coral monitoring trips across 131 reefs over more than 30 years, the scientists found the number of reefs hit by disturbances had gone up from 6% in the 1980s to 44% in the 2010s. 

‍

In March 2024, George Roff from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) flew over North Point of the Great Barrier Reef using a drone. He saw that the coral showed signs of fluorescing, something that happens when corals release a bright fluorescent color into their flesh, as a type of protection from extreme heat stress. 

‍

Is there a solution? The Australian government has promised to spend 1.2 billion Australian dollars over the years up until 2030 to improve things like water quality which has an impact on coral reefs. For us as individuals, there's small things we can do every day that are sure to have a positive impact. This one goes without saying, but dispose of trash properly. If it can be recycled, make sure it gets disposed of in the proper bins; don't litter; and don’t leave trash on the beaches. The second way is to minimize the use of fertilizers. Nutrients like phosphorus and nitrogen wash off into the ocean and harm ocean life. Most importantly, just spread the word. Tell your friends and family about this pressing issue, and educate the community. 

If we all work together and put in our best efforts, change is imminent. 

‍

Works Cited

“Great Barrier Reef.” UNESCO World Heritage Centre, https://whc.unesco.org/en/list/154/ 

Igini, Martina. “At Least 97% of Corals Dead in Northern Great Barrier Reef.” Earth.Org, 26 June 2024, https://earth.org/drone-imagery-shows-97-of-corals-dead-in-northern-great-barrier-reef/ . 

“97% of northern Barrier Reef coral has died following bleaching event.” BBC, 27 June 2024, https://www.bbc.co.uk/newsround/articles/cg33mpkxk9po. .

Readfearn, Graham. “'Most of it was dead': scientists discovers one of Great Barrier Reef's worst coral bleaching events.” The Guardian, 26 June 2024, https://www.theguardian.com/environment/article/2024/jun/26/most-of-it-was-dead-scientists-discovers-one-of-great-barrier-reefs-worst-coral-bleaching-events 

Straneo, Fiamma. “Ocean Warming.” Woods Hole Oceanographic Institution, https://www.whoi.edu/know-your-ocean/ocean-topics/climate-weather/ocean-warming/ 

“What are corals? | ICRI.” International Coral Reef Initiative (ICRI), https://icriforum.org/about-coral-reefs/what-are-corals/ 

“What You Can Do to Help Protect Coral Reefs | US EPA.” Environmental Protection Agency (EPA), 5 June 2024, https://www.epa.gov/coral-reefs/what-you-can-do-help-protect-coral-reefs 

Image Credits: 

https://mashable.com/article/great-barrier-reef-mortality

‍