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gerontocrat

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Coral Reefs
« on: April 11, 2024, 06:52:50 PM »
The coral reefs are very much another canary in the coalmine for climate change
Maybe they deserve a thread all to themselves, as they may well be all gone even before summer Arctic Sea Ice does.

https://www.theguardian.com/environment/2024/apr/11/great-barrier-reef-severe-coral-bleaching-impact
Quote
Great Barrier Reef suffering ‘most severe’ coral bleaching on record as footage shows damage 18 metres down

Marine researcher ‘devastated’ by widespread event that is affecting coral species usually resistant to bleaching


Concern that the Great Barrier Reef may be suffering the most severe mass coral bleaching event on record has escalated after a conservation group released footage showing damage up to 18 metres below the surface.

Dr Selina Ward, a marine biologist and former academic director of the University of Queensland’s Heron Island Research Station, said it was the worst bleaching she had seen in 30 years working on the reef, and that some coral was starting to die.

The Great Barrier Reef Marine Park Authority last week said aerial surveys of more than 1,000 individual reefs revealed more than half were rated as having high or very high levels of bleaching, and a smaller number in the south – less than 10% of the total – had extreme bleaching. Only about a quarter were relatively unaffected.

It confirmed the 2,300-kilometre reef system was experiencing its fifth mass bleaching event in eight years. The authority said sea surface temperatures had been between 0.5C and 1.5C hotter than expected for this time of year.

The Australian Marine Conservation Society on Thursday released video and photos that it said showed bleaching on the southern part of the reef extended to greater depths than had been previously reported this year.

Ward said the impact of bleaching had been extensive across 16 sites that she visited in the reef’s southern section, affecting coral species that had usually been resistant to bleaching. Some coral had started to die, a process that usually takes weeks or months after bleaching occurs.

“I feel devastated,” she said. “I’ve been working on the reef since 1992 but this [event], I’m really struggling with.”

Ward said sea temperatures at two of the sites she visited were the same at the surface and 20 metres below the surface. This was “very unusual”, and reinforced the need for rapid action to reduce greenhouse gas emissions, she said.

“What are we doing to stop the reef from being lost?” Ward said. “We cannot expect to save the Great Barrier Reef and be opening new fossil fuel developments. It’s time to act and there are no more excuses.”

Coral bleaching occurs when the coral becomes heat stressed and ejects the tiny marine algae, known as zooxanthellae, that live in its tissue and give most of its colour and energy. With the zooxanthellae gone, the coral starves and its bone-white calcium skeleton becomes visible.

If the elevated temperature doesn’t last long, the coral can recover. Otherwise, it starts to die. In the most severe cases, the bleaching is skipped and the coral dies almost immediately, usually turning a dirty brown.

Terry Hughes, an emeritus professor at James Cook University and longtime reef bleaching researcher, said the aerial surveys showed “the most widespread and most severe mass bleaching and mortality event ever recorded on the Great Barrier Reef”.

He said the scale of the damage was comparable to 2016, the worst previous year experienced, but there were now fewer individual reefs untouched by bleaching between southern Queensland and the Torres Strait. He said the area south of Townsville had been particularly badly hit this year.

“We’re already seeing extensive loss of corals at the time of peak bleaching,” he said. “It’s heartbreaking to see damage as severe as this as soon as this.”

Hughes said every part of the reef system had now bleached at least once since 1998. Some reefs had bleached three or four times. He said the cumulative damage made it harder for reefs to recover and more likely they would succumb.

The Intergovernmental Panel on Climate Change in 2018 found that most tropical coral reefs would be lost if global heating was limited to an average of 1.5C above pre-industrial levels and 99% were likely to be lost of heating reached 2C. They found they would be at high risk at 1.2C, a level that may have already been reached.

Dr Lissa Schindler, an ecologist and the reef campaign manager with the Australian Marine Conservation Society, called on the Great Barrier Reef Marine Park Authority to release maps showing the extent and severity of the bleaching so the public had a true picture of the scale of the impact.

Schindler also urged the authority, which she described as the reef’s custodian, to play a greater role in advocating for stronger action on emissions.

She said in the past the authority had called for “strong and fast national action” to deal with the climate crisis, but a more recent climate statement it issued focused on global action and did not say anything about Australia needing to increase what it was doing.

“If the Albanese government is serious about its commitment to Unesco to protect the reef then it must commit to net zero emissions by 2035 and stop approving new fossil fuel projects,” she said.

Scientists have said the government’s emissions reduction targets – a 43% cut compared with 2005 levels and net zero by 2050 – are consistent with global action that could lead to 2C of global heating.

Interviewed on ABC’s Radio National on Wednesday, the environment minister, Tanya Plibersek, said the government was “very concerned about the bleaching that we see at the moment, sadly, not just on the Great Barrier Reef, but right around the world”.

She said the government was doing “whatever we can” to get to net zero emissions. “We need to protect the reef because it’s … unique in the world and also 64,000 people rely on it for their work,” she said.

A reef authority spokesperson said it confirmed in early March that widespread coral bleaching was unfolding. They said in-water coral surveys were continuing and a report including data and maps would be published “in the coming weeks”.
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kassy

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Re: Coral Reefs
« Reply #1 on: April 11, 2024, 08:19:56 PM »
Not all but many will be in trouble. The frequency of bleaching for the GBR is problematic. Most earlier reports are probably in the Holocene Extinction thread.

 

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kiwichick16

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Re: Coral Reefs
« Reply #2 on: April 12, 2024, 04:24:27 AM »
the consensus from the IPCC suggests "most " reefs will be lost at +1.5 degrees .....and 99% of them at +2 degrees

i think i read somewhere that the GBR generates 60,000 jobs ....but of course its the loss of protection from storms ....particularly on low lying atolls ,that may result in the worst devastation

kiwichick16

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Re: Coral Reefs
« Reply #3 on: April 16, 2024, 04:50:49 AM »

KiwiGriff

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Re: Coral Reefs
« Reply #4 on: April 16, 2024, 07:57:52 AM »
Tropic water are surprising low in nutrients.
Coral are the king pin of a very complex  ecology that uses the abundant sunlight to maximize the mass of life supported by the low nutrient environment.
Many commercial fish species spend part of their life cycles among the reefs.
Reefs also protect shores from erosion.
Besides the natural beaty and diversity losing them will have far reaching impacts on economy's in regions they are found .
Animals can be driven crazy by placing too many in too small a pen. Homo sapiens is the only animal that voluntarily does this to himself.
Notebooks of Lazarus Long.
Robert Heinlein.

kassy

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Re: Coral Reefs
« Reply #5 on: April 16, 2024, 11:12:46 AM »
Coral bleaching: Fourth global mass stress episode underway - US scientists

Coral around the world is turning white and even dying as recent record ocean heat takes a devastating toll.

It has triggered the fourth global mass coral bleaching event, according to the US National Oceanic and Atmospheric Administration (NOAA).

Bleaching happens when coral gets stressed and turns white because the water it lives in is too hot.

Coral sustains ocean life, fishing, and creates trillions of dollars of revenue annually.

...

The first warning signs were in the Caribbean last year when bathers found the water off the coast of Florida was as warm as a hot tub.

That heat moved into the southern hemisphere. It has now affected more than half the world's coral including in Australia's Great Barrier Reef, and in coastlines in Tanzania, Mauritius, Brazil, Pacific islands, as well as in the Red Sea and Persian Gulf.

...

For 10 days in February scientist Neal Cantin flew a plane over the Great Barrier Reef for Australia's Institute of Marine Science. The UN heritage site stretches 2,000km, or roughly the length of the US east coast.

"For the first time ever we've documented very high levels of bleaching in all three areas of the Great Barrier Reef Marine Park," Dr Cantin says. The levels are likely to kill lots of coral, he adds.

Coral is vital to the planet. Nicknamed the sea's architect, it builds vast structures that house 25% of all marine species.

...

https://www.bbc.com/news/science-environment-68814016
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kassy

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Re: Coral Reefs
« Reply #6 on: May 18, 2024, 07:13:30 PM »
'Very unexpected and extreme': Coral bleaching has never been this bad, experts say


'This wouldn't be happening without climate change', said the head of the United States' Coral Reef Watch Program

Ocean temperatures that have gone “crazy haywire” could make the current global coral bleaching the worst in history.

It's so bad that scientists are hoping for a few hurricanes as they cool the oceans.

More than three-fifths - 62.9% - of the world's coral reefs are badly hurting from a bleaching event that began last year and is continuing.

...

How bad is coral bleaching in the Atlantic?
In the Atlantic, off the Florida coast and in the Caribbean, about 99.7% of the coral reefs have been hit with "very very severe'' losses in staghorn and elkhorn species, Manzello said Thursday in NOAA's monthly climate briefing.

62 countries are seeing damaged coral, with Thailand shutting off a tourist-laden island to try to save the coral there.

Meteorologists say a La Nina - a natural cooling of parts of the Pacific that changes the weather worldwide - is forecast to develop soon and perhaps cool oceans a bit, but Manzello said it may be too little and too late.

“I still am very worried about the state of the world's coral reefs just because we're seeing things play out right now that are just very unexpected and extreme,” Manzello said.

...

https://www.euronews.com/green/2024/05/17/very-unexpected-and-extreme-coral-bleaching-has-never-been-this-bad-say-scientists
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Rodius

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Re: Coral Reefs
« Reply #7 on: May 19, 2024, 07:09:24 AM »
Well... thats depressing

kiwichick16

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Re: Coral Reefs
« Reply #8 on: May 19, 2024, 07:27:33 AM »
and could be devastating for the people who derive a significant percentage of their protein from the marine environment

Freegrass

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Re: Coral Reefs
« Reply #9 on: May 19, 2024, 07:56:06 AM »
and could be devastating for the people who derive a significant percentage of their protein from the marine environment
That's only 1 billion poor people. Nobody cares about them until they start migrating. And then we don't want them anymore. We just want their fish that we destroyed...
When factual science is in conflict with our beliefs or traditions, we cuddle up in our own delusional fantasy where everything starts making sense again.

Carbon for the Carbon God

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Re: Coral Reefs
« Reply #10 on: May 19, 2024, 06:22:32 PM »
and could be devastating for the people who derive a significant percentage of their protein from the marine environment

I'm investing in CAFOs as we speak. Loss of marine protein is bullish for landlubber protein.

kiwichick16

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Re: Coral Reefs
« Reply #11 on: May 20, 2024, 02:02:19 AM »
high income countries consume 5 times more food derived from marine environments than low income countries

https://openknowledge.fao.org/server/api/core/bitstreams/9df19f53-b931-4d04-acd3-58a71c6b1a5b/content/sofia/2022/consumption-of-aquatic-foods.html

Rodius

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Re: Coral Reefs
« Reply #12 on: May 20, 2024, 05:23:55 AM »
high income countries consume 5 times more food derived from marine environments than low income countries

https://openknowledge.fao.org/server/api/core/bitstreams/9df19f53-b931-4d04-acd3-58a71c6b1a5b/content/sofia/2022/consumption-of-aquatic-foods.html

It is information like that which supports my idea that rich countries will suffer much more than many expect.

kassy

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Re: Coral Reefs
« Reply #13 on: May 23, 2024, 05:53:40 PM »
Thai sea temperatures hit ‘boiling’ record, bleaching almost all coral

Scientists say ‘almost all of the species have bleached’ as ocean temperatures in Eastern Gulf of Thailand reached 32.7C


...

The once vibrant and colourful corals, about five metres (16 feet) underwater, have turned white in a phenomenon known as coral bleaching, a sign that their health was deteriorating, due to higher water temperatures, scientists say.

Sea surface temperatures in the Eastern Gulf of Thailand reached 32.7C (90.9F) earlier this month while underwater readings are slightly warmer, with dive computers showing around 33C, data shows.

...

The Trat archipelago is home to over 66 islands, with over 28.4 square kilometres (2,841 hectares) of coral reef, where Lalita has found that up to 30 per cent of coral life was bleaching and 5 per cent had already died.

If water temperatures do not cool, more coral will die, Lalita said.

“It’s global boiling, not just global warming,” she said.

Rising temperatures were also impacting other marine life and the livelihoods of local fishermen including Sommay Singsura.

In recent years, his daily catch of seafood has been dwindling. Previously he had been able to make up to 10,000 baht ($275) a day, but now sometimes he comes back empty handed.

“There used to be jackfish, short mackerel, and many others ... But now, the situation isn’t good. The weather isn’t like what it used to be,” Sommay laments.

...

https://www.independent.co.uk/climate-change/news/thailand-heat-coral-reef-bleaching-b2550015.html
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Freegrass

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Re: Coral Reefs
« Reply #14 on: May 23, 2024, 07:31:37 PM »
So sad. I learned how to dive in Thailand, on Koh Phi Phi Island, where they shot the movie The Beach. I left when DiCaprio showed up. I'd already lived for a year on that Island by then, going all the way to divemaster. And the corals were gorgeous.

Then the Tsunami happened. Many of my friends died. I could have even been one of them, because I went home 2 weeks before it, to celebrate Christmas at home.

When I came back, all the corals were badly damaged, because of bleaching, and the tsunami.

With these temperatures, there won't be any corals left. I remember the dive water being between 26°C and 29°C when we dove. Above 30°C, there was bleaching. 33°C is simply a disaster...
When factual science is in conflict with our beliefs or traditions, we cuddle up in our own delusional fantasy where everything starts making sense again.