Climate: Heat-adapted corals not immune to bleaching

Intertidal Acropora corals exposed to air at low tide.

Intertidal Acropora corals exposed to air at low tide. Photo courtesy Dr. Verena Schoepf.

A matter of degrees …

Staff Report

Even corals living in some of the warmest ocean waters on the planet are susceptible to bleaching and heat stress, according to Australian researchers who studied unique tidal species in the Kimberley region.

When the water gets too warm, it breaks down the symbiosis between coral and their zooxanthellae (the microscopic plants which gives coral most of its colour), which can be fatal for the coral.

In the new study by scientists at the ARC Centre of Excellence for Coral Reef Studies said they were surprised to find that corals around the Kimberley region in north Western Australia are just as sensitive to heat stress and bleaching as their counterparts from less extreme environments elsewhere. Continue reading

NOAA says coral reefs worldwide hit by bleaching

Extensive stand of severely bleached coral at Lisianski Island in the Papahanaumokuakea Marine National Monument in Hawaii, documented during an August 2014 NOAA research mission. (Credit: NOAA).

Extensive stand of severely bleached coral at Lisianski Island in the Papahanaumokuakea Marine National Monument in Hawaii, documented during an August 2014 NOAA research mission. (Credit: NOAA).

Up to 95 percent of U.S. coral reefs may be affected

Staff Report

Global warming is causing global coral bleaching, ocean scientists said today, confirming that rising ocean temperatures are resulting in massive and widespread impacts to reefs around the world.

“The coral bleaching and disease, brought on by climate change and coupled with events like the current El Niño, are the largest and most pervasive threats to coral reefs around the world,” NOAA’s Coral Reef Watch coordinator, Mark Eakin, said in a statement. Continue reading

Climate: Coral reefs taking a big hit this year

A diverse coral reef in the U.S. Virgin Islands. PHOTO BY CAROLINE ROGERS/USGS.

Coral reefs in the Caribbean, like this one in the U.S. Virgin Islands, are at risk of bleaching as global warming heats up the world’s oceans. Photo by Caroline Rogers/USGS.

Warm oceans leading to widespread reef bleaching

Staff Report

FRISCO — Ocean researchers have updated their warnings of potential coral reef bleaching based on unusually warm ocean temperatures across the north Pacific, equatorial Pacific, and western Atlantic oceans this summer.

Scientists with NOAA’s coral reef watch say they expect  bleaching of corals on Northern Hemisphere reefs through October, potentially leading to the death of corals over a wide area and affecting the long-term supply of fish and shellfish.

“The bleaching that started in June 2014 has been really bad for corals in the western Pacific,” said Mark Eakin, NOAA Coral Reef Watch coordinator. “We are worried that bleaching will spread to the western Atlantic and again into Hawaii.” Continue reading

NOAA reports major coral bleaching in 2014

Hawaii bleaching the worst on record

CoralDegreeHeatingWeeks_global_4096

Coral reefs experienced major heat stress in 2014. Map courtesy NOAA Climate.gov – Dan Pisut.

Staff Report

FRISCO — Even without a surge of El Niño ocean heat, there was widespread coral bleaching across parts of the Pacific Ocean and the Caribbean this past summer.

Reefs in the Florida Keys saw their worst bleaching episode since 1997-1999, when a major El Niño was followed by strong La Niña conditions, NOAA scientists reported recently. The surprising intensity of bleaching across multiple ocean basins in 2014 has scientists wondering what to expect in 2015, when El Niño is forecasted to finally develop. Continue reading

Global warming: Study maps coral reef vulnerability

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Global warming threatens coral reef diversity. Photo courtesy NOAA.

74 percent of world’s reefs could see annual bleaching events by 2035

By Summit Voice

FRISCO — Using the latest data from the upcoming IPCC climate assessment, ocean researchers have concluded that about three-quarters of the world’s coral reefs could face annual bleaching events in just a short 30 years, and they’ve mapped out which areas will be hit first.

“This study represents the most up-to-date understanding of spatial variability in the effects of rising temperatures on coral reefs on a global scale,” said researcher Serge Planes, Ph.D., from the French research institute CRIOBE in French Polynesia. Continue reading

Biodiversity: Great Barrier reef has lost half its coral cover

Outbreaks of the coral eating crown of thorns starfish have been responsible for 42 percent of the over 50 percent decline in coral cover on the Great Barrier Reef between 1985 and 2012. Photo courtesy Katharina Fabricius, Australian Institute of Marine Science.

Multiple short-interval disturbances causing long-term decline, with southern areas hit hardest

By Summit Voice

SUMMIT COUNTY — Australian researchers say the Great Barrier Reef has lost half its coral cover in the past 27 years, with more impacts expected as the climate warms in coming decades. About half (46 percent) of the loss was from storm damage, with another 42 percent attributed to crown of thorns starfish and 10 percent lost to bleaching.

“We can’t stop the storms but, perhaps we can stop the starfish. If we can, then the reef will have more opportunity to adapt to the challenges of rising sea temperatures and ocean acidification, says John Gunn, CEO of the Australian Institute of Marine Science in Townsville. Continue reading

Global warming: More bad news for coral reefs

New global assessment predicts significant damage to majority of reef ecosystems unless greenhouse gases are curbed drastically

Staghorn coral. Photo courtesy NOAA.

By Summit Voice

SUMMIT COUNTY — Most coral reefs are likely doomed unless humankind acts quickly to curb greenhouse gas emissions, according to a new global assessment of global warming impacts published last week in Nature Climate Change.

“Our findings show that under current assumptions regarding thermal sensitivity, coral reefs might no longer be prominent coastal ecosystems if global mean temperatures actually exceed 2 degrees Celsius above the pre-industrial level,” said lead author Katja Frieler, of the Potsdam Institute for Climate Impact Research. “Without a yet uncertain process of adaptation or acclimation, however, already about 70 percent of corals are projected to suffer from long-term degradation by 2030 even under an ambitious mitigation scenario.”

The threshold for protecting at least half the world’s coral reef ecosystems is estimated at 1.5 degrees Celsius, according to the study conducted by scientists from Potsdam, the University of British Columbia in Canada and the Universities of Melbourne and Queensland in Australia. Continue reading

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