wildsingapore news: bleaching-events

Showing posts with label bleaching-events. Show all posts

Showing posts with label bleaching-events. Show all posts

Great Barrier Reef outlook very poor, Australia says

BBC 30 Aug 19;

The Great Barrier Reef's outlook has been officially downgraded from poor to very poor due to climate change.

Rising sea temperatures thanks to human-driven global warming remain the biggest threat to the reef, a five-year Australian government report says.

Actions to save it "have never been more time critical", the report reads.

Stretching over 2,300km (1,400 miles), the reef was designated a World Heritage site in 1981 for its "enormous scientific and intrinsic importance".

But in recent years the reef has been increasingly damaged by warmer seas which have killed off coral and affected its long-term health.

Thirty-year study reveals cause of coral bleaching crisis

Brooks Hays UPI 16 Jul 19;

July 16 (UPI) -- Corals are disappearing across the world's oceans, and most scientists have pointed to warming water temperatures -- the result of climate change -- as the primary driver. But new research suggests nitrogen pollution is the main cause of coral bleaching in Florida.

The study, published this week in the journal Marine Biology, was compiled using three-decades worth of observational data collected at the Looe Key Reef in the lower Florida Keys.

"Our results provide compelling evidence that nitrogen loading from the Florida Keys and greater Everglades ecosystem caused by humans, rather than warming temperatures, is the primary driver of coral reef degradation at Looe Key Sanctuary Preservation Area," lead study author Brian Lapointe, research professor at Florida Atlantic University's Harbor Branch Oceanographic Institute, said in a news release.

Australia: Great Barrier Reef hard coral cover close to record lows

Coral bleaching, crown-of-thorns starfish and cyclones reduced coverage to 10% to 30% over past five years
Adam Morton The Guardian 11 Jul 19;

Hard coral cover on the Great Barrier Reef is near record lows in its northern stretch and in decline in the south, surveys by government scientists have found.

A report card by the government’s Australian Institute of Marine Science says hard coral cover in the northern region above Cooktown is at 14% – a slight increase on last year but close to the lowest since monitoring began in 1985.

A series of “disturbances” – coral bleaching linked to rising water temperatures, crown-of-thorns starfish outbreaks and tropical cyclones – have caused hard coral cover to decline to between 10% and 30% across much of the world heritage landmark over the past five years.

Mike Emslie, the institute’s acting head of long-term monitoring, said the report included glimmers of hope: individual reefs, including those on the outer shelf in the Whitsunday Islands, were found to have lively communities and tiny juvenile corals were discovered across the 2,300km reef system. The density of juvenile coral suggested recovery was possible if there were not further disturbances.

He said it indicated there was some resilience in the system but added: “The important thing is the absence of further disturbances. If we have more coral bleaching events all bets are off.”

Devastating coral bleaching around French Polynesia

RNZ 12 Jun 19;

A coral bleaching around the French Polynesian islands of Tahiti and Mo'orea is being described as the most devastating seen in years.

But what's worried scientists most is that it took them by surprise.

Thailand: Coral bleaching off Koh Phi Phi

Kritsada Mueanhawong The Thaiger 31 May 19;

Corals at Koh Phi Phi near a famous driving point has started to bleach.

Paranya Pantajit, a scuba expert in Krabi says, “Corals near a famous diving point at Koh Phi Phi is beaching. There are many marine lives living around this coral.”

“The temperature at 8 metres deep in the sea is about 31 degree Celsius. Corals in in other islands in Krabi have started to bleach as well.”

India: Coral bleaching intensifies in Gulf of Mannar

THOOTHUKUDI The Hindu 26 May 19;

The intensity of coral bleaching has increased in the Gulf of Mannar and Palk Bay in May. However, no mortality has been witnessed so far.

While the prevalence of bleaching was less than 3% during April in the Gulf of Mannar, it has increased significantly in May.

During a rapid survey conducted from May 15-23 by the Suganthi Devadason Marine Research Institute, a total of nine reef areas including two reef areas in Thoothukudi group (Vaan, Koswari and Kariyachalli Islands), three in Mandapam Group (Shingle, Krusadai and Hare Islands), three others in Keelakarai group (Mulli, Valai and Thalaiyari Islands) and reefs in Palk Bay were surveyed.

In the Keelakarai group, which was the most affected, the prevalence of bleaching has increased significantly up to 35% (Mulli Island) from 3% in April. In the Mandapam group (Krusadai Island), the bleaching went up from 6% to 28% during the period. Twelve percent of corals have suffered bleaching in Palk Bay.

Thailand: Coral bleaching situation begins to improve

NNT 26 May 19;

Bangkok – Jatuphorn Burusphat, Director-General of the Department of Marine and Coastal Resources (DMCR), says a recent inspection of the coral in Thailand’s national marine parks has shown an improvement on the bleaching situation in many areas.

It was found that most coral bleaching in 51 areas in the Andaman Sea and 72 areas in the Gulf of Thailand has started to improve due to the arrival of the rainy season, which decreases sea temperatures. Most of the affected corals have begun to recover but are still pale.

India: Coral bleaching observed near Mandapam, Keezhakkarai, Palk Bay

Shubashree Desikan The Hindu 22 May 19;

When a coral bleaches, it does not die but comes pretty close to it. Some of the corals may survive the experience and recover once the sea surface temperature returns to normal levels.

The National Centre for Coastal Research, an institute under the Ministry of Earth Sciences, in India, has a field research station in the Gulf of Mannar region, and researchers led by Dr. Shanmugaraj have found an alarming pattern of bleaching in the reefs in Mandapam, Keezhakkarai and Palk Bay. They have found that sea surface temperature ranged from 28.7°C to 31°C in the August 2018-February 2019 period and there was no bleaching seen then. However, when the temperatures rose to between 32°C and 36°C between March 2019 and May 2019, researchers observed a pattern of bleaching in corals, which was different at different layers within the sea.

Coral bleaching event underway in French Polynesia despite no El Nino

Jo Khan ABC 21 May 19;

Widespread coral bleaching has been reported in the French Polynesian islands of Tahiti and Moorea, even though there was no El Nino event this year.

Key points:
More than 50 per cent of coral reefs around Tahiti and Moorea have been bleached
Bleached corals have been observed as deep as 100 metres
Scientists are concerned the lack of climate action will spell the end of the world's reefs

The reefs are among the most regularly bleached in the world, thanks to their position in the path of warm waters that spread west from South America during El Nino years.

This year, however, without the presence of an El Nino and the warmer water it brings, the reefs should have been spared.

But in the last few days, it's been estimated that 50 to 60 per cent of corals on reefs around Tahiti and Moorea have been bleached, according to marine biologist Luiz Rocha from the Californian Academy of Sciences.

Thailand: Nearly half of coral off Nai Yang damaged, killed by bleaching

PHUKET: Specialists from the Department of Natural Parks, Wildlife and Plant Conservation (DNP) have discovered that some 10% of coral off Nai Yang Beach are dead because of bleaching while 30% more damaged.
Waranya Prompinpiras The Phuket News 18 May 19;

The discovery was made during a joint inspection by the Phuket Marine National Park Operation Center 2 and Sirinath National Park on Thursday (May 16).

“Officers from the Phuket Marine National Park Operation Center 2 and Sirinath National Park checked the condition of coral at the depth of 1.5-5 meters off Nai Yang beach. We found that 10% of Staghorn Coral, Hump Coral, Cauliflower Coral and Mushroom Coral were killed by bleaching. Some 30% are damaged by bleaching, but still alive,” an officer from the Phuket Marine National Park Operation Center 2 told The Phuket News.

Still the forecast is optimistic due to changing weather conditions.

Thailand: Massive corals off Rayong start bleaching

The Thaiger 10 May 19;

Massive and aged corals have started to bleach off the coast of Rayong in the Gulf of Thailand.

Dr Thon Thamrongnawasawat, assistant dean of the Faculty of Fisheries at Kasetsart University and a marine biologist says, “The coral in Rayong has started to bleach. From a bird eye view we can see clearly the white coral around around the rocks under the water. ”

“These are massive corals which are bleaching very quickly. Normally this kind of coral takes a long time to bleach and react to the changes in temperature and environment.”

Thailand: Coral off Phuket suffering from bleaching

The Thaiger 27 Apr 19;

Corals have started to bleach off the coast of Phuket. The problem is due to the warming of the sea, according to reports from the Phuket-based operations centre of the 2nd National Marine Park.

Marine scientists at the centre conducted a survey of coral reefs off Nai Yang beach in the Sirinat national park last Thursday and found that the sea surface temperature was over 30 degrees Celsius and that 10% of the staghorn and mushroom corals, between 1-4 metres deep, had started to bleach, although they are not yet dead.

The report says that, if the warming of the sea continues, the coral bleaching problem will become more serious and will affect the ability of the reefs to regenerate.

Coral bleaching in Arabian Gulf modulated by shamal winds, say NYUAD researchers

Emirates News Agency 29 Apr 19;

ABU DHABI, 29th April, 2019 (WAM) -- Corals in the Arabian Gulf are not immune to extreme heat events associated with global warming that are impacting coral reefs elsewhere in the world, researchers at New York University Abu Dhabi have revealed.

Using reef-based temperature loggers and mathematical models, research published in the journal Frontiers in Marine Science, showed that coral in the Gulf - the most thermally tolerant in the world - has become more vulnerable to bleaching events when weak summer winds do not cool the water's surface.

Without these winds, which are known as shamal (northerly) winds, the Gulf’s shallow waters can reach temperatures considered lethal to coral for extended periods in summer, according to the study’s authors, NYUAD Associate Professor of Biology John Burt, and NYUAD Associate Professor of Mathematics Francesco Paparella.

Corals in Gulf of Mannar feel the heat

Hariprasad A R THOOTHUKUDI The Hindu 21 Apr 19;

Around 2.5% bleaching witnessed during underwater study

Coral reefs in the Gulf of Mannar region, which were recovering well since the last mass coral bleaching witnessed in 2016, have once again started bleaching due to rising temperatures this summer.

During an underwater study by the Suganthi Devadason Marine Research Institute (SDMRI), the extent of bleaching was estimated to be 2.5%, of which 2% was partially bleached while 0.5% has suffered full bleaching.

Great Barrier Reef suffers 89% collapse in new coral after bleaching events

Study shows dramatic fall in baby coral numbers but also change in type of coral
Lisa Cox The Guardian 3 Apr 19;

The number of new corals on the Great Barrier Reef crashed by 89% after the climate change-induced mass bleaching of 2016 and 2017.

Scientists have measured how many adult corals survived along the length of the world’s largest reef system and how many new corals they produced in 2018 in the aftermath of severe heat stress and coral mortality.

The results, published in Nature, show not only a dramatic reduction in new coral recruitment compared with historic levels, but also a change in the types of coral species produced.

Australia: Lord Howe Island coral bleaching 'most severe we've ever seen', scientists say

Biologists fear they will now start to see coral mortality in world’s southern-most reef
Lisa Cox The Guardian 1 Apr 19;

Researchers have documented what they are describing as the most severe coral bleaching to hit the world’s southern-most reef at Lord Howe Island.

Scientists from Newcastle University, James Cook University and the National Oceanic and Atmospheric Administration have spent the past two weeks surveying corals around the island in the far south Pacific Ocean after they were alerted to bleaching in isolated areas.

Bill Leggat, a coral biologist at Newcastle University, said the worst of the bleaching was in shallow water closer to the shoreline.

“It’s quite variable but where it’s severe it is actually quite severe,” he said.

Coral reefs near equator less affected by ocean warming

Research based on analysis of field observations from 20-year global coral survey
Florida Institute of Technology Science Daily 20 Mar 19;

Ocean warming is threatening coral reefs globally, with persistent thermal stress events degrading coral reefs worldwide, but a new study has found that corals at or near the equator are affected less than corals elsewhere.

The findings from Florida Institute of Technology Ph.D. student Shannon Sully and professor Rob van Woesik, along with colleagues at the University of California at Santa Barbara and Reef Check, were published March 20 in the journal Nature Communications.

The work, which was supported by the National Science Foundation and the Zegar Family Foundation, was based on analysis of field observations from a 20-year global survey of over 3,500 coral study sites led by Reef Check founder and former director Gregor Hodgson.

As expected, coral bleaching was most common in localities experiencing high-temperature stress, but it was significantly less common in those places with high monthly variation in temperatures.

Body of warm water in Indian Ocean heading to Malaysia

The Star 7 Mar 19;

PETALING JAYA: A conservation group monitoring coral in Malaysian waters has warned of a body of warm water forming in the Indian Ocean which can lead to coral bleaching.

Reef Check Malaysia general manager Julian Hyde said a review of information from the United States’ National Oceanic and Atmospheric Administration (NOAA) showed that the body of warm water was slowly moving eastwards towards Malaysia.

“We haven’t had reports of bleaching yet. It’s a little early.

“For bleaching to start, there needs to be several consecutive weeks of warm water, which requires an even more extended stretch of hot weather. So far, nothing yet,” he said in a statement yesterday.

Ocean heatwaves devastate wildlife, worse to come

Marlowe HOOD, AFP Yahoo News 5 Mar 19;

Paris (AFP) - Invisible to people but deadly to marine life, ocean heatwaves have damaged ecosystems across the globe and are poised to become even more destructive, according to the first study to measure worldwide impacts with a single yardstick.

The number of marine heatwave days has increased by more than 50 percent since the mid-20th century, researchers reported in the journal Nature Climate Change.

"Globally, marine heatwaves are becoming more frequent and prolonged, and record-breaking events have been observed in most ocean basins in the past decade," said lead author Dan Smale, a researcher at the Marine Biological Association in Plymouth, Britain.

Above the ocean watermark, on Earth's surface, 18 of the last 19 years have been the warmest on record, leading to more severe storms, droughts, heatwaves and flooding.

"Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems," Smale told AFP.

Some Great Barrier Reef coral suffering lasting effects from mass bleaching events

Several reefs have not recovered from back-to-back bleaching, surveys have found, but others remain in good condition
Lisa Cox The Guardian 4 Mar 19;

Coral reefs in the far north of the Great Barrier Reef are showing lasting effects from the mass bleaching of 2016 and 2017 and in some cases their health has declined further, according to fresh surveys by the Australian Institute of Marine Science.

Preliminary results of surveys by Aims scientists in January show several reefs have not recovered from the back-to-back bleaching, although the agency said some reefs they surveyed were in good condition.

Researchers undertook a 25-day expedition to remote far northern reefs, at a cost of $1.4m, partly funded by the Great Barrier Reef Foundation from money it was awarded in a record grant by the government last year.

Some of the reefs examined had not been surveyed before.

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