The world’s coral reefs are much larger than previously estimated, thanks to a combination of satellite images, machine learning, and on-ground knowledge from a global network of experts. Utilizing these tools, researchers have discovered an additional 64,000 square kilometers of coral reefs, equivalent to the size of Ireland. This brings the total size of shallow reefs (0-20 meters deep) to 348,000 square kilometers, which is roughly the size of Germany. The newly identified areas include regions with a hard bottom, likely teeming with significant coral growth.
Previous attempts to assess the extent of coral reefs relied on data from various sources, making it challenging to determine their precise size. However, now with high-resolution satellite imagery covering the entire globe, researchers can identify reefs as deep as 30 meters. By combining this data with observations and records from over 400 individuals and organizations working in coral reef regions worldwide, a team of nearly 500 researchers and collaborators has created the most comprehensive map of coral reef extent and composition ever produced, called the Allen Coral Atlas.
The detailed maps produced by the Allen Coral Atlas are already proving invaluable for reef management agencies worldwide. These maps are being employed to plan and assess conservation efforts, as well as to monitor threats to reefs. The newfound coral reefs are particularly evident in interactive sliders, where areas off the coast of far north Queensland, Australia, showcase the newly detected coral.
The maps offer three levels of detail. The first one is the broadest, representing the entire coral reef ecosystem, revealing light areas of coral surrounded by darker, deeper water. The second level provides geomorphic detail, illustrating the appearance of different areas within the reef, such as sandy lagoons, exposed reef crests, and sloping areas leading into deeper waters. The final level offers fine detail of the benthic substrates, showcasing areas dominated by coral cover. This information is crucial since coral polyps require a hard surface, such as rocks, to grow.
These discoveries come at a crucial time for coral reefs worldwide. While researchers are uncovering the full extent of shallow water reefs, they are also finding large new black coral reefs in deeper waters. However, corals are also facing significant challenges, including the warming and acidification of oceans due to climate change. Rising sea temperatures are particularly detrimental to coral polyps, which cannot tolerate excessive heat. This is alarming since coral reefs are home to a quarter of all oceanic species and are vital for biodiversity.
Nevertheless, the comprehensive maps generated by the Allen Coral Atlas are already driving real-world change. They have sparked new conservation efforts in countries including Indonesia, Pacific island nations, Panama, Belize, Kenya, and Australia. These maps provide a valuable tool for preserving and protecting coral reefs, offering hope for the future of these fragile ecosystems.
In conclusion, sophisticated techniques combining satellite imagery, machine learning, and on-ground knowledge have revealed that coral reefs are significantly larger than initially believed. This newfound knowledge, as showcased by the comprehensive maps created through the Allen Coral Atlas, is leading to increased conservation efforts and the protection of these vital marine environments. Despite the challenges posed by climate change, the enhanced understanding of coral reef extent and composition offers hope for the preservation of these remarkable ecosystems.
