coral bleaching

Increasingly Frequent Ocean Heat Waves Trigger Mass Die-Offs of Sealife, and Grief in Marine Scientists

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https://insideclimatenews.org/news/01052024/ocean-heat-waves-killing-sealife/

Marine biologist Anne Hoggett records bleached and dead coral around Lizard Island on the Great Barrier Reef in Australia on April 5. Credit: David Gray/AFP via Getty Images

Heat waves recently extended across nearly 30 percent of the world’s oceans, an expanse equivalent to the surface area of North America, Asia, Europe and Africa.

Over the past several years, the temperature of the Earth’s oceans have been spiking high enough to trigger numerous die-offs of marine species, killing millions of corals, fish, mammals, birds and plants. Those mass die-offs also have sent a wave of emotional trauma washing over some researchers watching their life’s work vanish before their eyes. 

“We talk a lot about eco grief, that sense of being overwhelmed and feeling loss,” said Jennifer Lavers, who has been tracking how thousands of seabirds have starved to death during recent ocean heat waves off the coast of western Australia as coordinator of the nonprofit marine research Adrift Lab.

Right now the extreme ocean heat in her region is waning, but globally, marine heat wave conditions extend across nearly 30 percent of the planet’s oceans, a surface area equivalent to all of North America, Europe, Asia and Africa. The harms of long-term gradual ocean warming are well documented, but Lavers said the most recent studies show that increasingly frequent pulses of extreme heat are doing the most damage to marine ecosystems.

With even more mass die-offs of ocean species projected, “scientists are leaving in droves from the field,” she said. “Incredibly skilled, talented, qualified, very passionate people are leaving because no matter what they say, what they do, how many papers they publish … It doesn’t matter.”

The creatures many scientists hoped to help with their research are still in decline and often they are worse off than they were when they started their work, including the flesh-footed shearwaters that she studies, she said.

“That’s the case for me,” she said. “I have to literally say to people that my job is to describe the extinction of a species.” 

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https://insideclimatenews.org/news/01052024/ocean-heat-waves-killing-sealife/

Continue ReadingIncreasingly Frequent Ocean Heat Waves Trigger Mass Die-Offs of Sealife, and Grief in Marine Scientists

Great Barrier Reef Suffering Record Coral Bleaching With Damage 59 Feet Below the Surface

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https://www.ecowatch.com/great-barrier-deep-coral-bleaching.html

New video footage released on April 11, 2024 shows that bleached corals on the southern part of the Great Barrier Reef extend to greater depths than has been reported during the current mass bleaching event. Australian Marine Conservation Society / Facebook screenshot

The Australian Marine Conservation Society (AMCS) has released video footage showing that the southern portion of the Great Barrier Reef is suffering from deep-sea coral bleaching, reported The Guardian.

The footage shows that the bleaching extends at least as far down as 59.1 feet — the deepest reported during this mass bleaching event, a press release from AMCS said. Some of the corals have begun to die in the face of record marine heat waves.

“I feel devastated. This bleaching event is the worst I have seen. It’s a severe bleaching event,” said Dr. Selina Ward, University of Queensland’s former academic director of the Heron Island Research Station, in the press release.

Ward reported extensive coral bleaching at all 16 southern Great Barrier Reef sites she had visited, saying it was the worst she had seen in three decades.

“I’ve been working on the Reef since 1992 but this [mass coral bleaching event], I’m really struggling with. The diversity of species involved has been hard to deal with. Look at bleached areas, there are many different species that are bleached – many of which are pretty resistant to bleaching so it’s not a pleasant one,” Ward added.

Last week, aerial survey data showed that 75 percent of the reef had experienced bleaching during the current bleaching event, with much of it classed as “high to extreme bleaching.”

During climate change-driven marine heat waves, extended periods of warmer ocean temperatures cause corals to become stressed, which leads them to expel the algae that live in a symbiotic relationship with them. These algae not only give corals their colorful appearance, but they are also their main source of energy, so long periods without them can lead to starvation.

“This new footage shows extensive coral bleaching in southern reefs, but there are images from the central and northern parts that show bleaching is extensive and severe in some of those areas too. Although in-water surveys will take months, the Great Barrier Reef Marine Park Authority has completed the aerial surveys but only released the data. The authority must urgently release the maps to show to the public the extent and severity of this bleaching event,” said Dr. Lissa Schindler, campaign manager with AMCS, in the press release.

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https://www.ecowatch.com/great-barrier-deep-coral-bleaching.html

Continue ReadingGreat Barrier Reef Suffering Record Coral Bleaching With Damage 59 Feet Below the Surface

NOAA Warns World’s Coral on Verge of ‘Worst Bleaching Event in History of the Planet’

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Original article by BRETT WILKINS republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).

A view of major bleaching on the coral reefs of the Society Islands on May 9, 2019 in Moorea, French Polynesia. (Photo: Alexis Rosenfeld/Getty Images).

“It’s looking like the entirety of the Southern Hemisphere is probably going to bleach this year,” one scientist said.

Driven by sustained climate-fueled oceanic heating, the planet is on the brink of another mass coral bleaching event that marine biologists warn could kill large swaths of tropical reefs including significant areas of Australia’s Great Barrier Reef.

Scientists are sounding the alarm following months of record ocean temperatures exacerbated by the planetary emergency and the El Niño climate pattern in the Pacific Ocean.

“It’s looking like the entirety of the Southern Hemisphere is probably going to bleach this year,” Derek Manzello of the National Oceanic and Atmospheric Administration’s (NOAA) Coral Reef Watch told Reuters. “We are literally sitting on the cusp of the worst bleaching event in the history of the planet.”

As NOAA explains:

When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. 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 2005, the U.S. lost half of its coral reefs in the Caribbean in one year due to a massive bleaching event. The warm waters centered around the northern Antilles near the Virgin Islands and Puerto Rico expanded southward. Comparison of satellite data from the previous 20 years confirmed that thermal stress from the 2005 event was greater than the previous 20 years combined.

Following the planet’s hottest summer on record last year, the Caribbean suffered its worst recorded bleaching event. The last worldwide bleaching occurred in 2014-17, when scientists say approximately 15% of all reefs experienced major coral deaths. Nearly a third of the Great Barrier Reef’s coral perished during the bleaching.

In the Southern Hemisphere, where summer is ending and ocean temperatures are at or near their annual peaks, there is “basically bleaching all over the place,” according to Manzello.

Matthew England, a professor at the University of New South Wales in Australia who studies ocean currents, recently told TheNew York Times that “the sea ice around the Antarctic is just not growing” and “the temperature’s just going off the charts.”

“It’s like an omen of the future,” he added.

It’s a similar story in the North Atlantic, which “has been record-breakingly warm for almost a year now,” University of Miami hurricane expert Brian McNoldy told the Times. “It’s just astonishing. Like, it doesn’t seem real.”

A 2018 report from the United Nations Intergovernmental Panel on Climate Change estimates that global heating of 1.5°C is likely to result in the loss of 70-90% the planet’s coral reefs over the coming decades.

Current emissions-based forecasts have Earth on track for at least 1.5°C of warming, which researchers say is likely to trigger five climate tipping points: melting of the Greenland and Antarctic ice sheets, mass die-off of warm-water coral reefs, thawing of Arctic permafrost, and collapse of the North Atlantic Subpolar Gyre circulation.

The European Environment Agency’s long-term forecasts for 2071-2100 predict worldwide oceanic heating of 0.5°C-3.8°C, depending on future greenhouse gas emission scenarios.

Scientists say the best way to avert worst-case outcomes for both coral reefs and the climate is to swiftly transition from fossil fuels to renewable energy. Reducing land-based pollution and overfishing are also critical to reef preservation.

Original article by BRETT WILKINS republished from Common Dreams under Creative Commons (CC BY-NC-ND 3.0).

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