Coral reefs play a critical role on the planet. They are some of the most biodiverse biomes, providing food and habitat for about 25% of all marine life and acting as nurseries for both natural and commercial fisheries. They also act as a physical barrier to protect coastal inhabitants from storms, and 40% of the human population rely on coral reefs in this way.
But rising sea temperatures and ocean acidity from climate change are greatly impacting coral reefs. Currently, one-quarter of coral reefs are beyond repair and two-thirds of reefs are at risk of permanent damage in the near future. Scientists predict that if warming continues at the current rate, 90% of the reefs will be dead by 2050.
That’s what makes the recently published global coral reef atlas from the Khaled bin Sultan Living Oceans Foundation and University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science so exciting. The atlas has over 65,000 square kilometers of maps of coral reefs and surrounding areas and scientists hope that it will act as a baseline for reef systems in a very turbulent time.
Using Earth-orbiting satellites and field observations from more than 1,000 remote coral reefs in 15 countries over 10 years, the team of scientists was able to develop high-resolution maps that show shallow water marine habitat in addition to information on the size of seagrass beds and mangrove forests. These components help the scientists determine if the health and resiliency of the studied reefs.
"Benthic habitat maps are an essential tool in coral reef conservation as they provide a snapshot of where reefs are located and the status of their health," said Alexandra Dempsey, the director of science management for the Khaled bin Sultan Living Oceans Foundation and a co-author of the paper. "Scientists will use these habitat maps as baseline data to help track changes in reef composition and structure over time."
Tracking these changes will require the use of technology like satellite, aircraft, and drone imaging, say the scientists. "In order to conserve something, it's imperative to know where it is located and how much of it you have," said Sam Purkis, professor and chair of the UM Rosenstiel School Department of Marine Geosciences. "Developing such an understanding for coral reefs is especially challenging because they are submerged underwater and therefore obscured from casual view. With this study, we demonstrate the potential to use satellite images to make coral reef maps at a global scale."
The maps were published recently in the journal Coral Reefs and will be a helpful resource in identifying areas that need conservation most urgently.