coral bleaching | Definition, Causes, Consequences, & Facts |


coral bleaching articles

Jul 19,  · Coral reefs won’t be out of hot water for quite a while. These normally colorful undersea ecosystems are under increasing stress, mostly because of warming oceans. Now, researchers report that a global coral bleaching event began in June The longest on record, it has sapped the color out of vast areas of coral — and now threatens their health/ Apr 09,  · The problem, according to Terry Hughes, director of the coral reef program at James Cook, is that bleaching is now so frequent and extreme off Australia that these corals are given "zero. Jan 16,  · Coral Bleaching Is Killing Reefs. Is the Answer a Great Migration? A spectacular submersible plunge reveals potential havens for organisms from hotter waterAuthor: Nsikan Akpan, Matt Ehrichs, PBS Newshour.

What is coral bleaching?

All rights reserved. Some areas, like this stretch at Heron Island, recovered. In another mile stretch, polyps eventually died. The largest living structure on Earth —an intricate marine system half the size of France, which nurtures 1, species of fish—is under attack by warm water for the second time in 12 months. And the window to save it is closing rapidly. Australia's Great Barrier Reef is suffering from another massive bleaching event, the first time in memory such episodes have hit in back to back calendar years, according to scientists at the Australian Research Council's coral reef program at James Cook University.

The scientists announced the results of recent aerial surveys of the reef on Sunday. There just is no question that this is tied to climate change. Bleaching typically occurs when pollutants, excess sunlight or unusually hot waters drive corals to expel symbiotic algae from their coral bleaching articles, turning corals white. The process doesn't necessarily kill corals immediately. If conditions improve—if the water cools again, say—many corals can be recolonized by algae and recover, coral bleaching articles.

But without the algae, which are their main source of food, corals grow weak and become more susceptible to disease. The problem, according to Terry Hughesdirector of the coral reef program at James Cook, coral bleaching articles that bleaching is now so frequent and extreme off Australia that these corals are given "zero opportunity" to rebound.

Last year's bleaching was far and away the worst on record. It struck the northern portion of the reef, killing, on average, about 67 percent of the corals in patchy sections along a mile stretch north of Cairns, Australia.

All that coral bleaching articles was done in less than a year. By comparison scientists a few years ago showed that it had taken more than a quarter of a century to kill just over half of the corals on other coral bleaching articles of the reef. This year, Hughes and his colleague James Kerry conducted another series of aerial surveys, coral bleaching articles, flying some 5, coral bleaching articles, miles as the southern summer ended and water temperatures—and bleaching—reached their peak.

What they saw troubled coral bleaching articles and other scientists greatly, coral bleaching articles. This year's event so far has hit the central section that was mostly spared last year, allowing existing damage to spread another miles.

We're just not getting any breaks whatsoever, and the severity of the problem is increasing with time. Today, that problem extends far beyond Australia, as corals around the world face a moment of reckoning. And that poses risks for hundreds of millions of people. Corals provide habitat for a quarter of the world's fish, and million or more people are believed to rely almost exclusively on marine creatures for protein.

Reefs also protect shorelines, reducing storm surges that can ravage coastal regions. Last year and were the two warmest years on record.

As greenhouse gas emissions from the burning of fossil fuels drive ocean temperatures up, climate change has become the single leading cause of bleaching events. And that's with air temperatures on average having increased only 1 degree Celsius 1. Climate scientists have said that even if the world moved at a lightning clip to combat warming, coral bleaching articles, it would be a significant struggle to keep temperature increases below 2 degrees Celsius—a goal set in December when nations and the European Union signed a climate accord in Paris.

Yet many scientists fear the world's corals would not survive even such a limited warming. Richmond said the next steps are obvious: The world needs to rapidly start reducing greenhouse gases while also eliminating smaller threats to corals—sedimentation and overfishing, for example. That could make remaining corals more resilient. Just last summer, during a gathering of more than 2, coral scientists in Hawaii, coral bleaching articles, researchers gathered signatures to send a letter to the prime minister of Australia—a leading coal exporter—to do more to combat carbon dioxide emissions.

Trump already is moving to unwind his predecessor's efforts to curb emission from coal-fired power coral bleaching articles, a major source of greenhouse gases. Most nations get it. Hughes, the lead author of a major study last month that called for immediate action to stem the damage to corals worldwide, said the problems were serious, but it was not too late.

As if to highlight his point, U. That could boost water temperatures even more. Read Caption. Warming Bleaches Two-Thirds of Great Barrier Reef A huge portion of the 1,mile structure has now suffered severe damage for the second straight year—and scientists blame climate change. By Craig Welch, coral bleaching articles. But it's not yet clear how committed the world really is. Continue Reading.


Coral bleaching


coral bleaching articles


An underwater investigation of coral bleaching in the South Pacific By Justin Worland | Photographs by XL Catlin Seaview Survey Richard Vevers has traveled the globe to photograph coral reefs. Coral bleaching, whitening of coral resulting from loss of symbiotic algae or degradation of the algae’s photosynthetic pigment. Bleaching is associated with the devastation of coral reefs, which are home to approximately 25 percent of all marine species. Jun 25,  · This is called coral bleaching. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality. In , the U.S. lost half of its coral reefs in the Caribbean in one year due to a massive bleaching event.