bleaching tagged posts

Third mass bleaching event, will corals survive?

bleached stag horn coral

The world is experiencing its third mass coral bleaching event. Due to elevated temperatures at tropical locations over the whole planet, large populations of corals are starting to turn white. This is bad, as bleaching can lead to large-scale decreases in coral health and ultimately their death. Coral reefs provide shorelines with protection from storms, are foundational to tropical tourism and provide critical habitat to thousands of species. Large-scale coral death following mass bleaching leads to reef erosion, loss of shoreline protection, loss of tourism income and the livelihoods that depend on them, and loss of critical habitat.

Following the last mass bleaching event in 1997-98, 16% of the world’s corals died...

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Late-season cyclone may ease coral bleaching threat

Coral Reef

The threat of major coral bleaching in the Great Barrier Reef looks to be receding with the onset of stormier weather including the formation of the first tropical cyclone of the season likely to cross the coast. Sea temperatures are warmer than average from about Townsville all the way down the coast to the NSW-Victorian border, creating one of the components for coral stress.

Unusually calm conditions over much of the Great Barrier Reef have also contributed to setting up possible bleaching events as clearer water lets more sunlight reach the sea floor. During bleaching events, corals expel the algae that provide as much as 90 per cent of the energy they need to grow and reproduce, killing some of them.

“Heat makes light toxic,” Andrew Baird, a coral reef ecologist at James Cook Univers...

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Pacific Coral “Worst die-off in 20 years”

coral bleaching

Scientists warn extreme sea temperatures could cause a “historic” coral reef die-off around the world over the coming months, following a massive coral bleaching already underway in the North Pacific. Experts said the coral die-off could be the worst in nearly two decades. Reports of severe bleaching have been accumulating in the inbox of the US National Oceanic and Atmospheric Administration’s (NOAA) Coral Reef Watch programme since July. A huge swathe of the Pacific has already been affected, including the Northern Marianas Islands, Guam, the Republic of the Marshall Islands, Hawaii, Kiribati and Florida. Some areas have recorded serious bleaching for the first time.

“On a global scale it’s a major bleaching event...

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Arabian Gulf coral reefs dying a slow death

Persian gulf's declining reefs

The coral content in Arabian Gulf reefs has declined by up to 50 per cent, posing a threat to fish stocks and marine habitats, an expert has warned. Dr John Burt, associate professor of biology at New York University Abu Dhabi (NYUAD), told Gulf News that extreme weather events also creates further stress and causes mass mortality of coral.

“A major weather event called El Nino is expected to occur again this summer. This usually raises water temperatures by 2.5 degrees Celsius. While El Nino’s effects vary, the one in 1998 caused great loss of corals around the world, including in the Arabian Gulf, and many have not yet been able to regenerate,” Dr Burt, who is also head of the NYUAD Marine Biology Laboratory, said.

“It is not usually possible to engineer solutions against wea...

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Can corals adapt to climate change?

Coral bleaching

The severe loss of coral reefs that is expected to occur over the 21st century may be offset somewhat if corals are able to adapt to the heat stress caused by climate change, a new study suggests. The study has uncovered evidence that corals may already be adapting to temperature changes in the ocean. However, reductions in coral bleaching are only expected to continue if greenhouse gas emissions are significantly reduced. The study was published on October 28, 2013 in Global Change Biology.

Coral bleaching is a process whereby warm water temperatures trigger the release of symbiotic algae, called zooxanthellae, living within the coral tissue. The algae supply the coral with valuable nutrients from photosynthesis...

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