[Marxism] Climate-Related Death of Coral Around World Alarms Scientists

Louis Proyect lnp3 at panix.com
Sun Apr 10 07:09:21 MDT 2016


NY Times, Apr. 10 2016
Climate-Related Death of Coral Around World Alarms Scientists
By MICHELLE INNIS

SYDNEY, Australia — Kim Cobb, a marine scientist at the Georgia 
Institute of Technology, expected the coral to be damaged when she 
plunged into the deep blue waters off Kiritimati Island, a remote atoll 
near the center of the Pacific Ocean. Still, she was stunned by what she 
saw as she descended some 30 feet to the rim of a coral outcropping.

“The entire reef is covered with a red-brown fuzz,” Dr. Cobb said when 
she returned to the surface after her recent dive. “It is otherworldly. 
It is algae that has grown over dead coral. It was devastating.”

The damage off Kiritimati is part of a mass bleaching of coral reefs 
around the world, only the third on record and possibly the worst ever. 
Scientists believe that heat stress from multiple weather events 
including the latest severe El Niño, compounded by climate change, has 
threatened more than a third of Earth’s coral reefs. Many may not recover.

Coral reefs are the crucial incubators of the ocean’s ecosystem, 
providing food and shelter to a quarter of all marine species, and they 
support fish stocks that feed more than one billion people. They are 
made up of millions of tiny animals, called polyps, that form symbiotic 
relationships with algae, which in turn capture sunlight and carbon 
dioxide to make sugars that feed the polyps.

An estimated 30 million small-scale fishermen and women depend on reefs 
for their livelihoods, more than one million in the Philippines alone. 
In Indonesia, fish supported by the reefs provide the primary source of 
protein.

“This is a huge, looming planetary crisis, and we are sticking our heads 
in the sand about it,” said Justin Marshall, the director of CoralWatch 
at Australia’s University of Queensland.

Bleaching occurs when high heat and bright sunshine cause the metabolism 
of the algae — which give coral reefs their brilliant colors and energy 
— to speed out of control, and they start creating toxins. The polyps 
recoil. If temperatures drop, the corals can recover, but denuded ones 
remain vulnerable to disease. When heat stress continues, they starve to 
death.

Damaged or dying reefs have been found from Réunion, off the coast of 
Madagascar, to East Flores, Indonesia, and from Guam and Hawaii in the 
Pacific to the Florida Keys in the Atlantic.

The largest bleaching, at Australia’s Great Barrier Reef, was confirmed 
last month. In a survey of 520 individual reefs that make up the Great 
Barrier Reef’s northern section, scientists from Australia’s National 
Coral Bleaching Task Force found only four with no signs of bleaching. 
Some 620 miles of reef, much of it previously in pristine condition, had 
suffered significant bleaching.

In follow-up surveys, scientists diving on the reef said half the coral 
they had seen had died. Terry Hughes, the director of the Center of 
Excellence for Coral Reef Studies at James Cook University in 
Queensland, who took part in the survey, warned that even more would 
succumb if the water did not cool soon.

“There is a good chance a large portion of the damaged coral will die,” 
he added.

Scientists say the global bleaching is the result of an unusual 
confluence of events, each of which raised water temperatures already 
elevated by climate change.

In the North Atlantic, a strong high-pressure cell blocked the normal 
southward flow of polar air in 2013, kicking off the first of three 
warmer-than-normal winters in a row as far south as the Caribbean.

A large underwater heat wave formed in the northeastern Pacific in early 
2014, and has since stretched into a wide band along the west coast of 
North America, from Baja California to the Bering Sea. Nicknamed the 
Blob, it is up to four degrees Fahrenheit warmer than surrounding 
waters, and has been blamed for a host of odd phenomena, including the 
beaching of hungry sea lions in California and the sighting of tropical 
skipjack tuna off Alaska.

Then came 2015, with the most powerful El Niño climate cycle in a 
century. It blasted heat across the tropical and southern Pacific, 
bleaching reefs from Kiritimati to Indonesia, and across the Indian 
Ocean to Réunion and Tanzania on Africa’s east coast.

“We are currently experiencing the longest global coral bleaching event 
ever observed,” said C. Mark Eakin, the Coral Reef Watch coordinator at 
the National Oceanic and Atmospheric Administration in Maryland. “We are 
going to lose a lot of the world’s reefs during this event.”

Reefs that take centuries to form can be destroyed in weeks. Individual 
corals may survive a bleaching, but repeated bleachings can kill them.

Lurid reports of damaged reefs started coming in from worried scientists 
in the summer of 2014.

Lyza Johnston, a marine biologist in the Northern Mariana Islands, dived 
to the reefs off Maug, a group of small islands: “In every direction, 
nearly all of the corals were bright white.”

Misaki Takabayashi, a marine scientist at the University of Hawaii at 
Hilo, surfed the waves above the blue rice coral there: “I could see 
what looked like bleached white ghosts popping up off the ocean floor at 
me.”

Cory Walter, a senior biologist at the Mote Marine Laboratory in 
Florida, peered down from a boat over Wonderland Reef off the Lower 
Florida Keys: “It almost looks like it snowed on the reef.”

Predicting the duration of the bleaching or forecasting the next one is 
difficult. The Blob has cooled somewhat, and El Niño, while weakening, 
is expected to stretch into 2017.

Dr. Eakin, the coral-reef specialist at the National Oceanic and 
Atmospheric Administration, said he expected the bleaching to continue 
for nine more months. Scientists will not be able to measure the full 
extent of the damage until it is over.

What is clear is that these events are happening with increasing 
frequency — and ferocity. The previous bleachings, in 2010 and 1998, do 
not appear to have been as extensive or prolonged as the current one.

The 1998 bleaching, which Dr. Eakin said had been set off by a fierce El 
Niño, killed around 16 percent of the world’s coral. By 2010, oceans had 
warmed enough that it took only a moderate El Niño to start another round.

Then in 2013, Dr. Eakin said, “a lot of bleaching happened due to 
climate change, before the El Niño had even kicked in.”

Reefs that were bleached in 2014, like those in the Florida Keys and the 
Caribbean, had no time to regenerate before suffering further thermal 
stress from El Niño last year, leaving the coral vulnerable to disease 
and death.

The reefs in the Florida Keys “are about to go into a third year 
straight of bleaching, something that has never happened before,” said 
Meaghan Johnson, a marine scientist at the Nature Conservancy. “We are 
worried about disease and mortality rates.”

Ove Hoegh-Guldberg, the director of Australia’s Global Change Institute, 
noted that 2015 was the hottest year ever recorded, both on land and in 
the oceans — breaking a record set just the year before.

“Rising temperatures due to climate change have pushed corals beyond 
their tolerance levels,” he said, adding that back-to-back bleaching can 
be particularly deadly to the corals.

El Niño warms the equatorial waters around Kiritimati Island more than 
anywhere else in the world, making it a likely harbinger for the health 
of reefs worldwide. That is why Dr. Cobb, the Georgia Tech scientist who 
made the recent dive, has been making the trek at least once a year for 
the past 18 to the tiny atoll, part of the Line Islands archipelago.

Though the atoll sits just north of the Equator, trade winds suck water 
up from the depths of the ocean, usually keeping the water temperature 
surrounding the reefs a healthy, nearly constant 78 degrees.

But in 2015, the expected upwelling of deep, cold water did not happen, 
Dr. Cobb said, speaking by satellite phone after her dive. So water in 
the atoll was 10 degrees warmer than normal, and never cooled enough to 
allow coral to recover.

“The worst has happened,” she said. “This shows how climate change and 
temperature stresses are affecting these reefs over the long haul. This 
reef may not ever be the same.”



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