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Annisa Nadyastiti / 11614383
Anggiana Yuanita Fardhani / 11614238
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The
direct sentences are highlighted in yellow.
Scientists race to prevent wipeout of world's
coral reefs
There were startling
colors on South Ari Atoll just a year ago, a dazzling array of life beneath the
waves. Now this Maldivian reef is dead. It was killed by the stress of rising
ocean temperatures. What's left is a haunting expanse of gray. It's a scene
repeated in reefs across the globe in what has fast become a full-blown
ecological catastrophe.
The Maldives are a group of coral atolls in the
Indian Ocean.
The world has lost roughly half its coral reefs
in the last 30 years. Scientists are now scrambling to ensure that at least a
fraction of these unique ecosystems survives beyond the next three decades. The
health of the planet depends on it. Coral reefs support a quarter of all marine
species, as well as half a billion people around the world.
"This
isn't something that's going to happen 100 years from now. We're losing them
right now," said marine biologist Julia Baum of Canada's University of
Victoria. "We're losing them really
quickly, much more quickly than I think any of us ever could have
imagined."
Even if the world could halt global warming now,
scientists still expect that more than 90 percent of corals will die by 2050.
Without drastic intervention, we risk losing them all.
"To lose coral
reefs is to fundamentally undermine the health of a very large proportion of
the human race," said Ruth Gates. She is director of the Hawaii Institute of Marine
Biology.
Coral reefs produce some of the oxygen we
breathe. Often described as underwater rainforests, they populate a tiny
fraction of the ocean. But they provide habitats for one in four marine
species. Reefs also form crucial barriers protecting coastlines from the full
force of storms.
They provide billions of dollars in revenue from
tourism, fishing and other commerce, and are used in medical research for cures
to diseases including cancer, arthritis and bacterial or viral infections.
"Whether
you're living in North America or Europe or Australia, you should be
concerned," said biologist Ove Hoegh-Guldberg, director of the Global
Change Institute at Australia's University of Queensland. "This is not
just some distant dive destination, a holiday destination. This is the fabric
of the ecosystem that supports us."
That fabric is being torn apart.
"You couldn't be more dumb...to erode the
very thing that life depends on - the ecosystem - and hope that you'll get away
with it," Hoegh-Guldberg said.
Corals are invertebrates, living mostly in
tropical waters. They secrete calcium carbonate to build protective skeletons
that grow and take on impressive colors, thanks to a symbiotic relationship
with algae that live in their tissues and provide them with energy.
But corals are sensitive to temperature
fluctuations, and are suffering from rising ocean temperatures and
acidification, as well as from overfishing, pollution, coastal development and
agricultural runoff.
A temperature change of just 1.8 to 3.6 degrees
Fahrenheit can force coral to expel the algae, leaving their white skeletons
visible in a process known as "bleaching."
Bleached coral can recover if the water cools,
but if high temperatures persist for months, the coral will die. Eventually the
reef will degrade, leaving fish without habitats and coastlines less protected
from storm surges.
The first global bleaching event occurred in
1998, when 16 percent of corals died. The problem spiraled dramatically in
2015-2016 amid an extended El Nino natural weather phenomenon that warmed
Pacific waters near the equator and triggered the most widespread bleaching
ever documented. This third global bleaching event, as it is known, continues
today even after El Nino ended.
Headlines have focused on damage to Australia's
famed Great Barrier Reef, but other reefs have fared just as badly or worse
across the world, from Japan to Hawaii to Florida.
Around the islands of the Maldives, an idyllic
Indian Ocean tourism destination, some 73 percent of surveyed reefs suffered
bleaching between March and May 2016, according to the country's Marine
Research Center.
"This
bleaching episode seems to have impacted the entire Maldives, but the severity
of bleaching varies" between reefs, according to local conditions. This is
according to Nizam Ibrahim, the center's senior research officer.
Worst hit have been areas in the central
Pacific. That is where the University of Victoria's Baum has been conducting
research on Kiritimati, or Christmas Island. It is in the Republic of Kiribati.
Warmer water temperatures lasted there for 10 months in 2015-2016. It killed a
staggering 90 percent of the reef.
Baum had never seen anything like it.
To make matters worse, scientists are predicting
another wave of elevated ocean temperatures starting in April.
"The
models indicate that we will see the return of bleaching in the South Pacific
soon, along with a possibility of bleaching in both the eastern and western
parts of the Indian Ocean," said Mark Eakin. He is a coral reef specialist and coordinator of the National Oceanic
and Atmospheric Administration's Coral Reef Watch. It uses satellites to
monitor environmental conditions around reefs. It may not be as bad as last
year, but it could further stress "reefs that are still hurting from the
last two years."
The speed of the destruction is what alarms
scientists and conservationists. Damaged coral might not have time to recover
before it's hit again by warmer temperatures.
Source: https://www.tweentribune.com/article/teen/scientists-race-prevent-wipeout-worlds-coral-reefs/
