Tag Archives: coral bleaching

Help NASA save the ocean’s corals by playing a new video game

The new game will help NASA find new ways of mapping coral reefs. (Image: NASA)

In an effort to save our coral reefs, and thus helping to save the planet, NASA is calling on video gamers and citizen scientists to assist them in mapping coral reefs around the world.

In the past few years, the Ames Research Center in California’s Silicon Valley has been developing new ways to peer below an ocean’s surface using “fluid-lensing” cameras. Mounted on drones or aircraft, the cameras have assisted the agency on expeditions to Puerto Rico, Guam, American Samoa, and elsewhere to collect 3D images of the ocean floor, including corals, algae, and seagrass. However, the data alone is not enough to help them gather the whole story of what is happening to corals, so they are reaching out to the public for help.

The data from the public’s help will be processed by a neural network called NeMO-Net, or the Neural Multi-Modal Observation and Training Network. The program allows players to identify and classify corals using these 3D images while virtually traveling the ocean on their own research vessel, the Nautilus.

On each “dive,” players interact with real NASA data, learning about the different kinds of corals that lie on the shallow ocean floor while highlighting where they appear in the imagery. Aboard their virtual research vessel, players will be able to track their progress, earn badges, read through the game’s field guide, and access educational videos about life on the seafloor.

“NeMO-Net leverages the most powerful force on this planet: not a fancy camera or a supercomputer, but people,” said principal investigator Ved Chirayath. “Anyone, even a first-grader, can play this game and sort through these data to help us map one of the most beautiful forms of life we know of.”

Coral reefs occupy less than 0.1% of the world’s ocean area, but provide a home for at least 25 percent of all marine species (Image: Pixabay)

As they play the game, players’ actions help train NASA’s Pleiades supercomputer at Ames to recognize corals from any image of the ocean floor, even those taken with less powerful instruments. The supercomputer “learns” from the coral classifications players make by hand, using machine learning techniques to classify on its own.

The hope is that data gathered from the game will help researchers find new ways to preserve coral reefs. A new study from James Cook University’s ARC Centre of Excellence for Coral Reef Studies recorded severe bleaching on the Great Barrier reefs during offshore dives in February and March. The study showed that some reefs had 90 percent of their shallow water corals bleached.

NASA is touting the game as both a learning experience along with being an important research tool. The more people who play NeMO-NET, they say, the more accurate Pleiades’ mapping abilities will become. After it has been able to accurately classify corals from low-resolution data included in the game, the supercomputer will be able to map out the world’s corals at an unprecedented resolution. With that map, NASA says scientists can better understand what is happening to corals and find ways to preserve them.

So while you’re currently stuck in your house under quarantine, why not help save the world while you’re at it?

You can play NeMO-NET on an iPad.

Bleached Acropora coral (foreground) and normal colony (background), Keppel Islands, Great Barrier Reef. Credit: Wikimedia Commons.

Climate change killed almost 90% of the baby coral in the Great Barrier Reef

Bleached Acropora coral (foreground) and normal colony (background), Keppel Islands, Great Barrier Reef. Credit: Wikimedia Commons.

Bleached Acropora coral (foreground) and normal colony (background), Keppel Islands, Great Barrier Reef. Credit: Wikimedia Commons.

Recent, major bleaching events in the Great Barrier Reef — the largest living structure on the planet — has dramatically compromised the recruitment of new corals. According to researchers, the number of juvenile corals that settled in the reef was 89% lower in 2018 than the historical average.

A bleak future

Australia’s Great Barrier Reef has been hampered by four mass coral bleaching events since 1998, the most recent one lasting from June 2014 to May 2017. This was the longest, most damaging coral bleaching event on record killing 30% of the reef. An estimated half billion people around the world directly depend on reefs for income from fishing and tourism. Economic activity derived from the Great Barrer Reef alone is thought to be worth $4.5 billion annually.

Bleaching occurs when the ocean’s waters become too warm and expel the photosynthetic algae, called zooxanthellae, which live in a symbiotic relationship with the coral. Without the algae, the coral dies and seaweeds take over. The main culprit is man-made climate change, which warms and increases the acidity of the waters. Although some think the effects of climate change are hazy and yet to rear their head, it has actually been affecting the reef for at least 20 years. A 2018 study found that the number of ocean heatwaves has risen by more than 50% since 1925, threatening to collapse marine ecosystems all over the world, coral reefs being no exception.

Scientists believe that under normal conditions, the coral would need 10 years to bounce back. But a new study led by researchers at ARC Centre of Excellence for Coral Reef Studies suggests conditions are anything but normal.

The rate of new coral recruitment is abysmally low. Researchers measured how many adult corals along the reef had survived following the mass bleaching events, as well as the number of new corals that had been produced in 2018. Compared to 1990-levels, a period where there were no bleaching events, there was an average 90% decline in coral recruitment across the whole length of the Great Barrier Reef.

Typically, when one reef is destroyed, it can be replenished by babies from another reef. However, the 2016 an 2017 bleaching was so severe that in many parts of the reef there were no longer any adjacent reefs to provide offspring.

Not only does the Great Barrier Reef’s future hang by a thread, what remains of it is also morphing dramatically. Some corals are more resilient than others, which means that they now breed more, altering the coral composition. For instance, the hardest hit species is Acropora, which saw a 93% decline.

Coral reefs are complex ecosystems, so when a coral species disappears, so does the habitat for countless other species of marine wildlife.

“The collapse in stock–recruitment relationships indicates that the low resistance of adult brood stocks to repeated episodes of coral bleaching is inexorably tied to an impaired capacity for recovery, which highlights the multifaceted processes that underlie the global decline of coral reefs. The extent to which the Great Barrier Reef will be able to recover from the collapse in stock–recruitment relationships remains uncertain, given the projected increased frequency of extreme climate events over the next two decades,” the authors wrote in their study.

If current trends continue unabated, coral bleaching might affect 99% of the world’s reefs within this century, the United Nations warns. Previously, the U.N. Intergovernmental Panel on Climate Change warned that tropical reefs could decline by 70% to 90%, if the planet warms by 1.5ºC compared to preindustrial average temperatures — the upper limit set by the Paris Agreement. At 2ºC of warming, 99% of the world’s reefs could perish.

“Going to 2C and above gets to a point where corals can no longer grow back, or you have annual bleaching events. On the other hand, at 1.5C there’s still significant areas which are not heating up or not exposed to the same levels of stress such that they would lose coral, and so we’re fairly confident that we would have parts of those ecosystems remaining,” said Professor Ove Hoegh-Guldberg, a coral reefs expert with the University of Queensland.

Last year, Australian scientists bred baby corals in an artificial environment and later moved them to some of the most damaged parts of the reef. Eight months later, the juvenile coral had survived and grown, lending hope that coral transplants can restore similarly damaged ecosystems, not just in the Great Barrier Reef, but around the world as well. However, this is just patchwork. The only viable long-term solution is cutting global greenhouse emission. But even if we manage to avert 1.5ºC of warming, the Great Barrier Reef will never be the same.

The findings appeared in the journal Nature.

Coral reef heart.

The death knell already sounded for coral reefs, it’s time to save anything we can

Coral reefs as we know them are doomed, a new paper reports. What we have to do now is try to save and conserve as much of them as we can — but even experts are at a loss as to how we might accomplish that.

Coral reef heart.

Image via Pixabay.

For decades, marine scientists have been trying to warn us that coral reefs can’t survive in the warmer world we are creating. Those warning calls have peaked and now, they make way for silence. Researchers today watch in stunned despair while the coral reefs as we know them limp their last sickly strides.

A new study published this Thursday, by a team of the world’s top coral experts, comes to sound the death knell of the oceans’ megalopolises. Surveys of over 100 reefs scattered all across the world revealed that extreme bleaching events — which occurred every 30 to 25 years before the 1980s — now take place every five or six years.

A frightful way to go

Corals start bleaching when they overheat. When faced with high temperatures, the host polyps (phylum Cnidaria) have a last-ditch survival strategy — they turn on the symbiotic algae which help feed them (zooxanthellae) and start to consume them alive. The algae that can’t survive the heat or the polyp’s voraciousness get thrown out in a bid to keep the coral as cool as possible.

It’s a desperate shot at survival, a heart-breaking attempt that effectively rips the coral family apart and turns it on each other. It’s ruthless and tragic, but in short bursts, it works. If conditions don’t improve rapidly, however, the wavering algae can’t supply enough photosynthesis to feed the polyp. Starved, the polyp stops its growth and becomes sickly. In the mid-long term, the increase in temperature will kill the corals outright.

Reefs can and do recover from bleaching events. Polyp larvae have no qualms about moving in an unclaimed coral and rebuilding. It does take time, however — about 10 years or so for the fastest-growing corals in a reef — to properly heal.

With the interval between bleaching events shortened five-fold, there simply isn’t enough time for the ecosystems to recover. These damaging events occur so frequently now that the reefs’ chances for recovery in the long term are virtually nil, the authors write. Huge swaths of today’s reefs — which collectively cover an area about the size of France — face almost certain death.

Dead reef.

A bleached coral reef. Image credits: NOAA.

It’s getting worse and worse

“These impacts are stacking up at a pace and at a severity that I never had anticipated, even as an expert,” said Kim Cobb, climate scientist and coral researcher at the Georgia Institute of Technology, not affiliated with the study, in an interview for Grist.

“It’s really the rapidity of it that is so sobering and shocking — and for me personally, life-altering.”

According to lead author Terry Hughes, a coral scientist at Australia’s James Cook University, “mass bleaching of corals was unheard of” before the 1980s.

Since then, things have gone horribly wrong. The paper reports that 94 of the 100 coral reefs the team surveyed have experienced at least one severe bleaching event since the 80s. The remaining six aren’t in a single solid chunk, but they’re scattered across the world — meaning there’s virtually no ocean basin on Earth whose coral reefs have been spared.

Study coauthor and coordinator of the National Oceanic and Atmospheric Administration’s Coral Reef Watch program, Mark Eakin, says that by 2050, ocean temperatures will be warm enough that 90% of all the world’s reefs will experience at least one bleaching event — every year.

“It is clear already that we’re going to lose most of the world’s coral reefs,” he confesses.

And when the corals go, oceans will heave and buckle. We won’t be spared either.

Neptune’s starving trident

Coral reefs provide a slew of essential services for humans and for ecosystems. Despite taking up only 0.1% of the ocean floor, up to 25% of all marine species depend on them for food, shelter, and mating habits. Fish from coral reefs feed over a billion people worldwide, my colleague Elena wrote last year. Those people will still need food — but we won’t have the reefs any longer.

Reefs also rake in billions of dollars every year from tourists visiting coastal areas or island chains to see the “rainforests of the sea”. These reefs will go, or at least change into a very, very different version of their current selves. Conservation biologist Josh Drew, not affiliated with the study, told Grist that the interval between bleaching events is, fundamentally, a “death warrant for coral reefs,” at least  “as we know them”.

“I’m not saying we’re not going to have reefs at all, but those reefs that survive are going to be fundamentally different,” he explains.

“We are selecting for corals that are effectively weedy, for things that can grow back in two to three years, for things that are accustomed to having hot water.”

The economies that today’s reefs prop up will crumble. The societies that depend on them for food will waver, some may not be able to recover. That’s only part of the price humans will pay for coral bleaching.

Right now, researchers are trying to understand what the loss of these linchpin ecosystems will do to the Earth in coming decades. Previous research suggests that the full impact may play out in a domino effect with disastrous consequences. Scientists such as Eakin are desperately trying to save whatever crumbs they still may, considering even “much more radical actions” than they would have previously.

Work is being done to breed genetically-modified super coral species that can live in the warmer, more acidic waters. Other groups are trying to identify the last few dozen reefs that have a shot at surviving. They plan to turn these into seed-banks to be called upon by future generations after climate change has stabilized. Even geoengineering is being considered as a last-ditch attempt to stabilize the climate in time to give reefs a fighting chance.

There’s no consensus on what will work. There’s no agreement on which one is most feasible. But that doesn’t matter because there’s one thing every expert agrees on — the reefs seem doomed, and this is our final shot at saving what’s left.

The paper “Spatial and temporal patterns of mass bleaching of corals in the Anthropocene” has been published in the journal Science.

 

 

Warming oceans could destroy corals in the Pacific and Atlantic, researchers warn

Coral populations are crucial to the health of oceanic environments, but they are also extremely vulnerable to changing conditions. Researchers warn that warming waters and ocean acidification lead to coral bleaching which can cause massive damage across both the Atlantic and the Pacific.

Image via NOAA.

Despite their appearance, corals are animals and not plants. They typically live in compact colonies of many identical individual polyps, secreting calcium carbonate to form a hard skeleton. Many corals from and rely on a symbiotic relationship with a class of algae. Via photosynthesis, these provide energy for the coral, and aid in calcification and as much as 30% of the tissue of a polyp may be plant material. In return, the algae benefit from a safe place to live and consume the polyp’s carbon dioxide and nitrogenous waste. All is fine as long as the coral is fine, but if the coral becomes stressed, then it can eject the algae, either through expulsion or loss of algal pigmentation – this is called coral bleaching, and it’s a major issue. Warming waters are especially threatening, as the National Oceanic and Atmospheric Administration (NOAA) explains:

“Warmer water temperatures can result in coral bleaching. 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.”

As unusually warm temperatures are sweeping through the equatorial Pacific, north Pacific and western Atlantic oceans coral bleaching is taking worrying proportions.

Two images of the Great Barrier Reef showing that the warmest water (top picture) coincides with the coral reefs (lower picture), setting up conditions that can cause coral bleaching. Image via Wikipedia.

“The bleaching that started in June 2014 has been really bad for corals in the western Pacific,” said Mark Eakin, NOAA’s Coral Reef Watch coordinator, in a news release on Monday. “We are worried that bleaching will spread to the western Atlantic and again into Hawaii.”

Much of this warming can be blamed on El Nino’s weather patterns, but this warming started way before – El Nino is only the accentuating factor. The frequency of this kind of events also indicates that overall warming is more of a concern than individual weather patterns.

“We’re seeing an actual progression that goes along with this sort of big event, but it’s happening without a huge El Nino,” he said. “We’re seeing the more frequent return of these events primarily because the water temperature without an El Nino is already so warm it takes less … to tip the scales and cause the corals to bleach.”

Earlier this year, NOAA’s Coral Reef Watch four-month Coral Bleaching Outlook accurately predicted coral bleaching in the South Pacific and in 2014, Hawaii saw widespread coral bleaching for the first time since 1996. If it also happens again this year, it would  be the first time in recorded history that this would happen two years in a row. This adds even more pressure, because while some corals may survive the bleaching, they need time to recover.

“Many healthy, resilient coral reefs can withstand bleaching as long as they have time to recover,” Eakin said. “However, when you have repeated bleaching on a reef within a short period of time, it’s very hard for the corals to recover and survive. This is even worse where corals are suffering from other environmental threats, like pollution or overfishing.”

Now, in a new study, NOAA researchers express their concerns once again – if we don’t do something to drastically curb our CO2 emissions, then coral populations will suffer.

“The paper reports that even if humans limit the Earth’s warming to two degrees C (3.8 degrees F), many marine ecosystems, including coral reefs, are still going to suffer,” said Eakin, an author on the paper. “The increase we are seeing in the frequency and severity of bleaching events is part of why the climate models in that paper predict a dire future for coral reefs.”

Journal Reference: J.-P. Gattuso et al. Contrasting futures for ocean and society from different anthropogenic CO2 emissions scenarios. Science 3 July 2015: Vol. 349 no. 6243. DOI: 10.1126/science.aac4722