Coral Bleaching Detected in the GBR since 1998: The role of the Atlas

March 18, 2022Makenna Flynn

Off the coast of Australia, the sixth wonder of the world sits below the waves and is both beautiful and critical to our planet - the Great Barrier Reef. The marine ecosystem captures carbon through seagrass and mangroves, generates significant economic activity through tourism, protects the coastline from storms and wave erosion, and supports thousands of marine species. 

But experts warn of a critical threat against this underwater wonder. Leading coral scientist, Professor Terry Hughes, is raising the alarm that the Great Barrier Reef is at the beginning of its sixth mass bleaching event since 1998. The Great Barrier Reef Marine Park Authority adds that low and moderate bleaching is being reported for different areas of the marine region. For some corals, this bleaching could be a death sentence.

But, what is coral bleaching?

First, it is important to know that coral is an animal. It survives through a symbiotic relationship with the algae called zooxanthellae. The zooxanthellae inhabits the coral and in turn, creates nutrients for the coral through photosynthesis. Zooxanthellae is also what gives the coral its colorful appearance.

However, when stressful situations such as warming water temperatures strike, the algae flees the coral. This means no more nutrients or vibrant colors, resulting in the distinctive “bleached” appearance.

Low to moderate bleaching detected on the Great Barrier Reef by the Allen Coral Atlas for week ending February 28, 2022. 

The Allen Coral Atlas responds

In 2021, the Allen Coral Atlas produced a beta bleaching monitoring system to complement its dashboard of data products. The first-of-its-kind resource offers scientists around the world an opportunity to monitor the bleaching in the Great Barrier Reef. Watching from satellites in space, the Atlas can dive below the waves and identify low, moderate, and severe bleaching levels.

To learn more about how the bleaching system works and its current development, we spoke with Gabi Bonelli, a postdoctoral researcher. She shared, “Our algorithm measures the temporal change, or how coral brightness changes over time. While the bleaching event in the Great Barrier Reef is tragic, it provides our team with an opportunity to validate and improve our algorithm to better combat coral bleaching in the future.” 

In the coming weeks, use the Allen Coral Atlas to measure coral bleaching in the Great Barrier Reef. Sign up for our newsletter below to stay up to date with Allen Coral Atlas progress and monitoring developments.