Satellite survey gives coral reef big picture
The Pearl and Hermes Atolls in Hawaii comprise the largest protected marine area in the world. (NASA)
A new satellite survey has let scientists pinpoint the location – and assess the health – of half a million square kilometers of coral reefs on planet Earth.
Only 18% of the world’s reefs are in what are called “marine protected areas.” They’re meant to safeguard the reefs. But the recent satellite survey found that Marine Protected Areas provide only limited security to coral reefs.
Earth & Sky spoke with Camilo Mora of Dalhousie University in Nova Scotia. He said the problem is that most of these areas are in developing countries. And in developing countries you have poverty and the people need to use the resources from the reefs – for example, fish.
Mora said that over-fishing near coral reefs is a problem because fish eat the algae that grow on coral. With fewer fish, the algae can overwhelm and kill entire reefs. And there are other threats as well, such as global warming.
Camilo Mora: Increases of only 1 or 2 degrees above the average ocean temperatures cause massive bleaching of coral reefs throughout the ocean.
Mora said protecting coral reefs is important because they’re home to as many as 9 million species of aquatic life and contribute billions of dollars in tourism to many countries around the world.
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Mora also told Earth & Sky, “On a global scale there are about half a million square kilometers of coral reefs and only 18% of those corals are in MPAs, or marine protected areas. But when you look at the effectiveness of this protection you’ll find that fewer than 2% of the world’s corals are within MPAs that are fully effective. That’s one of the uses of these databases. For the first time we were able to see how much of the world’s corals are protected.”
He added, “Coral reefs also affected by things like pollution and coastal development. In the Caribbean, there are 2 billion people living on the coasts, and you can imagine the amount of pollution produced and how that impacts reefs. So that’s a factor we analyze.”
“Threats are happening at global scales,” he said, “so when you want to look at a global scale you need to have maps of reefs also at the global scale. I spent almost a year compiling very basic data on maps on 400 countries. Getting this info on the actual area of reefs would be impossible to do by hand, going country by country characterizing reefs. It would just be impossible to do.”
“With satellite images we can have access to all that information, and for first time ever we were able to know exactly where coral reefs are located and the exact position of these coral reefs anywhere on this planet.”
“Basically, the value of these images is that we know where the coral reefs are and that’s something we did not know before.”
For more information:
NASA Coral Reef Images Key to New Global Survey
World’s coral reef left vulnerable by paper parks
Our thanks to:
Camilo Mora
Department of Biological Sciences
Dalhousie University
Additional Teacher Resources
NOAA: National Ocean Service – Education
NOAA’s National Ocean Service (NOS) provides free online educational materials that help educators and students learn about coral reefs, oceans, and more. This website includes lesson plans, subject tutorials, interviews with scientists, exercises with real data, and case studies. These resources incorporate audio, video, and animations.
NOAA: Coral Reef Outreach and Education
The links provided at this website include resources for students interested in learning more about reefs, as well as lesson plans and other useful information for educators. For example, there is a link to a curriculum on Remote Sensing and Coral Reefs for 4th – 6th grade.
NOAA: Photo Library – The Coral Kingdom
This online photo library includes high-resolution images of fish, invertebrates and scuba divers from Caribbean, Pacific and Red Sea coral reefs.
NASA: SeaWiFS Project
This website provides educators with a variety of resources including an online color presentation about oceans, The Living Ocean teacher’s guide and poster, and links to other educational resources for teachers.
