Given the high costs of ocean exploration and the still nascent technology to carry it out, we know relatively little about what lies underwater. In order to better understand the mysteries of the oceans, a team of scientists is using satellite images capable of mapping, with an unprecedented level of detail, one of the most iconic underwater ecosystems on the planet: the shallow coral reef.
Although little is said about them, coral reefs are home to a quarter of all marine species and provide food, livelihoods, security and recreation for at least one billion people. However, pollution, overfishing and heat waves stemming from climate change threaten their existence.
Most of the coral reefs have yet to be mapped. This is why a group of scientists have set themselves the goal of monitoring, in real time, these biodiverse underwater ecosystems to protect and restore them. They also want to identify coral segments that are naturally more resistant to climate change. These shelters may contain secrets that allow us to mitigate the impact of warming seas on coral reefs.
This is the ambitious Allen Coral Atlas project, led by Vulcan, a philanthropic organization created by Microsoft co-founder Paul Allen. The United Nations Environment Program (UNEP) is working with Vulcan to build the capacities of coral reef professionals, managers and policy makers around the world, especially in developing countries, on how use the new atlas. On the program Chuck Cooper, director of government and community relations for Vulcan, said that “The atlas aims to improve our understanding of coral reef systems and promote better policies, based on evidence, to protect them.”
The atlas, open to the public, uses satellite technology to create high-resolution images of the corals that are then processed into detailed maps. These maps capture characteristics that will allow scientists and the conservation community to compare the health of coral reefs over time and understand the pressures reefs face.
One phenomenon that the atlas will be able to monitor is whitening. This occurs when corals – tiny animals that secrete calcium carbonate for protection – are stressed by factors such as hot water or pollution. As a result, they expel microscopic symbiotic algae called zooxanthellae, which reside within their tissues. Then the corals take on a ghostly tone: they “bleach”.
This innovative project will provide relevant information to monitor coral reef bleaching phenomena and other short-term changes. This evidence can inform policy-making and, at the same time, serve as compelling scientific information to capture public interest in the precarious situation of corals.
The starting points of the atlas
Three years ago, Paul Allen assigned Vulcan responsibility for saving the world’s corals, says Paulina Gerstner, Allen Coral Atlas program manager. “As a technologist, he saw huge data gaps and challenged us to figure out how to apply the nascent availability of satellite imagery to map and monitor the world’s coral reefs. All of them, ”says Gerstner. Allen, an avid diver who passed away in 2018, was deeply committed to protecting marine ecosystems. He had already been funding coral research before, but his concern intensified in 2017 when he discovered that his favorite reef dive sites were bleached. It was then that he tasked the team with the ambitious goal of mapping the world’s corals.
UNEP is training officials from coastal states in the use of the atlas and supporting efforts to develop policies that protect coral reefs. In addition to Vulcan, which is funding the project, there are other partners, including the University of Queensland, Planet Inc., Arizona State University, and the National Geographic Society.
The atlas uses imagery from Planet Labs, which operates the world’s largest fleet of Earth observation satellites. On a daily basis, Planet Labs satellites photograph the entire surface of the Earth in minute detail. The researchers will analyze the satellite images and produce maps that catalog the depths of the reefs and their location and, at the same time, differentiate them from other underwater habitats and features, such as seagrass, rocks and sand.