[Marxism] Large Sections of Australia’s Great Reef Are Now Dead, Scientists Find

Louis Proyect lnp3 at panix.com
Thu Mar 16 06:55:46 MDT 2017


NY Times, Mar. 16 2017
Large Sections of Australia’s Great Reef Are Now Dead, Scientists Find
By DAMIEN CAVE and JUSTIN GILLIS

SYDNEY, Australia — The Great Barrier Reef in Australia has long been 
one of the world’s most magnificent natural wonders, so enormous it can 
be seen from space, so beautiful it can move visitors to tears.

But the reef, and the profusion of sea creatures living near it, are in 
profound trouble.

Huge sections of the Great Barrier Reef, stretching across hundreds of 
miles of its most pristine northern sector, were recently found to be 
dead, killed last year by overheated seawater. More southerly sections 
around the middle of the reef that barely escaped then are bleaching 
now, a potential precursor to another die-off that could rob some of the 
reef’s most visited areas of color and life.

“We didn’t expect to see this level of destruction to the Great Barrier 
Reef for another 30 years,” said Terry P. Hughes, director of a 
government-funded center for coral reef studies at James Cook University 
in Australia and the lead author of a paper on the reef that is being 
published Thursday as the cover article of the journal Nature. “In the 
north, I saw hundreds of reefs — literally two-thirds of the reefs were 
dying and are now dead.”

The damage to the Great Barrier Reef, one of the world’s largest living 
structures, is part of a global calamity that has been unfolding 
intermittently for nearly two decades and seems to be intensifying. In 
the paper, dozens of scientists described the recent disaster as the 
third worldwide mass bleaching of coral reefs since 1998, but by far the 
most widespread and damaging.

The state of coral reefs is a telling sign of the health of the seas. 
Their distress and death are yet another marker of the ravages of global 
climate change.

If most of the world’s coral reefs die, as scientists fear is 
increasingly likely, some of the richest and most colorful life in the 
ocean could be lost, along with huge sums from reef tourism. In poorer 
countries, lives are at stake: Hundreds of millions of people get their 
protein primarily from reef fish, and the loss of that food supply could 
become a humanitarian crisis.

With this latest global bleaching in its third year, reef scientists say 
they have no doubt as to the responsible party.

They warned decades ago that the coral reefs would be at risk if human 
society kept burning fossil fuels at a runaway pace, releasing 
greenhouse gases that warm the ocean. Emissions continued to rise, and 
now the background ocean temperature is high enough that any temporary 
spike poses a critical risk to reefs.

“Climate change is not a future threat,” Professor Hughes said. “On the 
Great Barrier Reef, it’s been happening for 18 years.”

Corals require warm water to thrive, but they are exquisitely sensitive 
to extra heat. Just two or three degrees Fahrenheit of excess warming 
can sometimes kill the tiny creatures.

Globally, the ocean has warmed by about 1.5 degrees Fahrenheit since the 
late 19th century, by a conservative calculation, and a bit more in the 
tropics, home to many reefs. An additional kick was supplied by an El 
Niño weather pattern that peaked in 2016 and temporarily warmed much of 
the surface of the planet, causing the hottest year in a historical 
record dating to 1880.

It was obvious last year that the corals on many reefs were likely to 
die, but now formal scientific assessments are coming in. The paper in 
Nature documents vast coral bleaching in 2016 along a 500-mile section 
of the reef north of Cairns, a city on Australia’s eastern coast.

Bleaching indicates that corals are under heat stress, but they do not 
always die and cooler water can help them recover. Subsequent surveys of 
the Great Barrier Reef, conducted late last year after the deadline for 
inclusion in the Nature paper, documented that extensive patches of reef 
had in fact died, and would not be likely to recover soon, if at all.

Professor Hughes led those surveys. He said that he and his students 
cried when he showed them maps of the damage, which he had calculated in 
part by flying low in small planes and helicopters.

His aerial surveys, combined with underwater measurements, found that 67 
percent of the corals had died in a long stretch north of Port Douglas, 
and in patches, the mortality reached 83 percent.

By luck, a storm stirred the waters in the central and southern parts of 
the reef at a critical moment, cooling them, and mortality there was 
much lower — about 6 percent in a stretch off Townsville, and even lower 
in the southernmost part of the reef.

But an Australian government study released last week found that over 
all, last year brought “the highest sea surface temperatures across the 
Great Barrier Reef on record.”

Only 9 percent of the reef has avoided bleaching since 1998, Professor 
Hughes said, and now, the less remote, more heavily visited stretch from 
Cairns south is in trouble again. Water temperatures there remain so 
high that another round of mass bleaching is underway, the Great Barrier 
Reef Marine Park Authority confirmed last week.

Professor Hughes said he hoped the die-off this time would not be as 
serious as last year’s, but “back-to-back bleaching is unheard-of in 
Australia.” The central and southern part of the reef had already been 
badly damaged by human activities like dredging and pollution.

The Australian government has tried to combat these local threats with 
its Reef 2050 plan, restricting port development, dredging and 
agricultural runoff, among other risks. But Professor Hughes’s research 
found that, given the high temperatures, these national efforts to 
improve water quality were not enough.

“The reefs in muddy water were just as fried as those in pristine 
water,” Professor Hughes said. “That’s not good news in terms of what 
you can do locally to prevent bleaching — the answer to that is not very 
much at all. You have to address climate change directly.”

With the election of Donald J. Trump as the American president, a recent 
global deal to tackle the problem, known as the Paris Agreement, seems 
to be in peril. Australia’s conservative government also continues to 
support fossil fuel development, including what many scientists and 
conservationists see as the reef’s most immediate threat — a proposed 
coal mine, expected to be among the world’s largest, to be built inland 
from the reef by the Adani Group, a conglomerate based in India.

“The fact is, Australia is the largest coal exporter in the world, and 
the last thing we should be doing to our greatest national asset is 
making the situation worse,” said Imogen Zethoven, campaign director for 
the Australian Marine Conservation Society.

Australia relies on the Great Barrier Reef for about 70,000 jobs and 
billions of dollars annually in tourism revenue, and it is not yet clear 
how that economy will be affected by the reef’s deterioration. Even in 
hard-hit areas, large patches of the Great Barrier Reef survived, and 
guides will most likely take tourists there, avoiding the dead zones.

The global reef crisis does not necessarily mean extinction for coral 
species. The corals may save themselves, as many other creatures are 
attempting to do, by moving toward the poles as the Earth warms, 
establishing new reefs in cooler water.

But the changes humans are causing are so rapid, by geological 
standards, that it is not entirely clear that coral species will be able 
to keep up. And even if the corals do survive, that does not mean 
individual reefs will continue to thrive where they do now.

Coral reefs are sensitive systems, built by unusual animals. The corals 
themselves are tiny polyps that act like farmers, capturing colorful 
single-celled plants called algae that convert sunlight into food. The 
coral polyps form colonies and build a limestone scaffolding on which to 
live — a reef.

But when the water near a reef gets too hot, the algae begin producing 
toxins, and the corals expel them in self-defense, turning ghostly 
white. If water temperatures drop soon enough, the corals can grow new 
algae and survive, but if not, they may succumb to starvation or disease.

Even when the corals die, some reefs eventually recover. If water 
temperatures stay moderate, the damaged sections of the Great Barrier 
Reef may be covered with corals again in as few as 10 or 15 years.

But the temperature of the ocean is now high enough that global mass 
bleaching events seem to be growing more frequent. If they become 
routine, many of the world’s hard-hit coral reefs may never be able to 
re-establish themselves.

Within a decade, certain kinds of branching and plate coral could be 
extinct, reef scientists say, along with a variety of small fish that 
rely on them for protection from predators.

“I don’t think the Great Barrier Reef will ever again be as great as it 
used to be — at least not in our lifetimes,” said C. Mark Eakin, a reef 
expert with the National Oceanic and Atmospheric Administration, in 
Silver Spring, Md.

Dr. Eakin was an author of the new paper and heads a program called 
Coral Reef Watch, producing predictive maps to warn when coral bleaching 
is imminent. Even though last year’s El Niño has ended, water 
temperatures are high enough that his maps are showing continued hot 
water across millions of square miles of the ocean.

Kim M. Cobb, a climate scientist at the Georgia Institute of Technology 
who was not involved in the writing of the new paper, described it and 
the more recent findings as accurate, and depressing. She said she saw 
extensive coral devastation last year off Kiritimati Island, part of the 
Republic of Kiribati several thousand miles from Australia and a place 
she visits regularly in her research.

With the international effort to fight climate change at risk of losing 
momentum, “ocean temperatures continue to march upward,” Dr. Cobb said. 
“The idea that we’re going to have 20 or 30 years before we reach the 
next bleaching and mortality event for the corals is basically a fantasy.”

Damien Cave reported from Sydney, and Justin Gillis reported from New York.




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