Just a few degrees of warming affects coral reefs
Listen to a 5-minute podcast with Mark Eakin from Earth & Sky's new Clear Voices podcast series. This is bleached coral from Paradise Reef, Mexico. Courtesy Mark Eakin, NOAA.
Mark Eakin is concerned about coral reefs around the globe.
And he wanted us to tell you that just a few degrees of ocean warming makes a big difference to the reefs.
Mark Eakin: Over the time that I’ve been diving on coral reefs such as those in the Florida Keys for over 30 years, we’ve seen major changes in the reef systems. They’ve been degraded over the last few decades tremendously. And so, much of the beautiful coloration that was present before, the lush life that was present in terms of the corals themselves, has died and left a system that is much less capable of supporting fish and other marine life.
Eakin is the project coordinator for NOAA’s Coral Reef Watch in Silver Spring, Maryland. He said that even a small ocean warming has profound effects.
Mark Eakin: These small increases in temperature that we’ve seen over the past two decades correspond with the increases in bleaching we’ve seen on a large scale.
Eakin said coral reefs might be able to recover from bleaching, but they’ll need to rapidly adapt to survive in a warmer ocean.
He said humans can help by cutting down other environmental stresses like pollution to give the reefs a fighting chance in a warming world.
Our thanks today to NOAA, the National Oceanic and Atmospheric Administration.
The images to the left show a coral becoming bleached over a three month period. Image courtesy US National Park Service, Virgin Islands National Park.
As ocean temperatures rise, corals begin to lose the algae that give them their food and vibrant color. The corals starve and turn white, or bleach. Coral bleaching episodes are now occurring more often, due to global warming, according to Eakin.
Eakin also said, “In 2005, two months of temperatures only one to two degrees above the normal summertime maximum caused corals to bleach and die across much of the Caribbean.
When ocean temperatures rise only one degree above normal, corals begin to lose the algae that provide their food and coloration. This bleaching can starve the corals and high temperatures also cause disease outbreaks. Warm waters in 2005 caused the most intense bleaching and death of corals ever seen in the Caribbean. Our satellite data show that the high temperatures that cause coral bleaching, disease, and death have increased over the last 22 years. As temperatures have risen over past decades, the problem of coral bleaching has become far worse around the world.”
“A few degrees of warming can make a big difference,” he said.
Additional Teacher Resources
NOAA: National Ocean Service – Education
NOAAs 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.
