ZME Science
No Result
View All Result
ZME Science
No Result
View All Result
ZME Science

Home → Science → News

The Great Barrier Reef had 5 near-death experiences so far, but this one might be its last

The Great Barrier Reef may be facing its worse threat yet.

Tibi PuiubyTibi Puiu
May 29, 2018
in Climate, Environment, News
A A
Share on FacebookShare on TwitterSubmit to Reddit

An analysis of fossil reef cores revealed that the world’s largest reef system has gone through multiple episodes that threatened to wipe it out over the last 30,000 years. During this timeframe, there were at least five really close calls due to all sorts of threats, such as sea level rises, temperature swings, and sediment increases.

Credit: Wikimedia Commons.
Credit: Wikimedia Commons.

In order to conduct their study, the researchers used underwater sonar to locate places on the seafloor — beyond the current reef — where corals may have grown in the past. They learned that Australia’s Great Barrier Reef experienced two massive death events due to air exposure 30,000 and 22,000 years ago. In response, the reef had to move seaward in order to survive. Another two widespread reef deaths occurred around 17,000 and 13,000 years ago due to rapid sea level rise, which drove the reef back landward. And most recently, around 10,000 years ago, large sediment increase and poor water quality killed entire stretches of the reef.

The researchers part of the 10-year, multinational effort could not drill for sediments everwhere, so they can’t confirm how extensive the die-offs were. What’s certain, however, is that these five identified episodes were especially destructive. The team, led by geoscientist Jody Webster from the University of Sydney, believes that as sea level rise and other factors killed wide portions of the reef, corals managed to persist in places along the continental shelf, providing a foothold from which the entire reef could become restored.

“Our study shows the reef has been able to bounce back from past death events during the last glaciation and deglaciation,” said Webster in a statement

“However, we found it is also highly sensitive to increased sediment input, which is of concern given current land-use practices.”

Drilling for the fossil reef cores. Credit: ECORD/IODP
Drilling for the fossil reef cores. Credit: ECORD/IODP

Today, the Great Barrier Reef is 2,300 km long and can be seen from space, lounging off the coast of Queensland, Australia. It’s also dying.

The findings are important in today’s context in which the Great Barrier Reef is threatened by a new massive die-off — and this time it’s caused by us. Human activity, particularly greenhouse gas emissions and pollution, have risen the ocean’s temperature and lowered the water’s pH, making it more acidic. This combination promotes coral bleaching, which occurs when the ocean’s waters become too warm, resulting in the expelling of photosynthetic algae called zooxanthellae that live in a symbiotic relationship with the coral. Without the algae, the coral dies and seaweeds take over.

Associate Professor Jody Webster on board the Great Ship Maya with a fossil core from the Great Barrier Reef. Credit: ECORD/IODP.
Associate Professor Jody Webster on board the Great Ship Maya with a fossil core from the Great Barrier Reef. Credit: ECORD/IODP.

According to a previous study published in Nature, roughly 29% of the 3,863 individual reefs that make up Australia’s Great Barrier Reef were affected by the abnormal warming. The consequences were dire: In some areas, up to 90% of the coral population died due to bleaching.

Previously, a 2016 study of 84 reefs along the Great Barrier Reef revealed that one-third of the those in the central and northern regions have died due to a huge bleaching event. Corals to the north of Cairns, which account for two-thirds of the Great Barrier Reef, are also massively affected, with 35% to 50% dead or dying. An estimated half billion people around the world directly depend on reefs for income from fishing and tourism. The Great Barrer Reef alone is thought to be worth $42 billion. 

RelatedPosts

A feathered foe: How Emus fought the Australian army — and won
Great Barrier Reef collapses at hand of Australian farmers
Australia’s environment is in crisis — and it’s just the beginning
Fluffy dinosaurs used to live at the South Pole, this treasure trove of fossil feathers suggests

“I have grave concerns about the ability of the reef in its current form to survive the pace of change caused by the many current stresses and those projected into the near future,” Webster said.

“Our study shows that as well as responding to sea-level changes, the reef has been particularly sensitive to sediment fluxes in the past and that means, in the current period, we need to understand how practices from primary industry are affecting sediment input and water quality on the reef,” he added.

Scientific reference: Jody M. Webster et al, Response of the Great Barrier Reef to sea-level and environmental changes over the past 30,000 years, Nature Geoscience (2018). DOI: 10.1038/s41561-018-0127-3.

Tags: australiacoralgreat barrier reef

ShareTweetShare
Tibi Puiu

Tibi Puiu

Tibi is a science journalist and co-founder of ZME Science. He writes mainly about emerging tech, physics, climate, and space. In his spare time, Tibi likes to make weird music on his computer and groom felines. He has a B.Sc in mechanical engineering and an M.Sc in renewable energy systems.

Related Posts

Science

Hidden for Centuries, the World’s Largest Coral Colony Was Mistaken for a Shipwreck

byTibi Puiu
5 months ago
News

New pterosaur species with huge tongue discovered in Australia

byTibi Puiu
11 months ago
Animals

Very rare marsupial mole sighted in Australia. It’s so tiny it fits between your fingers

byTibi Puiu
1 year ago
Anthropology

This legendary aboriginal land not only existed — it’s an archaeological time capsule

byMihai Andrei
1 year ago

Recent news

Pungent Penguin Poop Produces Polar Cloud Particles

May 23, 2025

A Team of Researchers Brought the World’s First Chatbot Back to Life After 60 Years

May 22, 2025
default

From Farms to Lost Cities, Drones Are Quietly Revolutionizing Modern Science

May 22, 2025
  • About
  • Advertise
  • Editorial Policy
  • Privacy Policy and Terms of Use
  • How we review products
  • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.

No Result
View All Result
  • Science News
  • Environment
  • Health
  • Space
  • Future
  • Features
    • Natural Sciences
    • Physics
      • Matter and Energy
      • Quantum Mechanics
      • Thermodynamics
    • Chemistry
      • Periodic Table
      • Applied Chemistry
      • Materials
      • Physical Chemistry
    • Biology
      • Anatomy
      • Biochemistry
      • Ecology
      • Genetics
      • Microbiology
      • Plants and Fungi
    • Geology and Paleontology
      • Planet Earth
      • Earth Dynamics
      • Rocks and Minerals
      • Volcanoes
      • Dinosaurs
      • Fossils
    • Animals
      • Mammals
      • Birds
      • Fish
      • Amphibians
      • Reptiles
      • Invertebrates
      • Pets
      • Conservation
      • Animal facts
    • Climate and Weather
      • Climate change
      • Weather and atmosphere
    • Health
      • Drugs
      • Diseases and Conditions
      • Human Body
      • Mind and Brain
      • Food and Nutrition
      • Wellness
    • History and Humanities
      • Anthropology
      • Archaeology
      • History
      • Economics
      • People
      • Sociology
    • Space & Astronomy
      • The Solar System
      • Sun
      • The Moon
      • Planets
      • Asteroids, meteors & comets
      • Astronomy
      • Astrophysics
      • Cosmology
      • Exoplanets & Alien Life
      • Spaceflight and Exploration
    • Technology
      • Computer Science & IT
      • Engineering
      • Inventions
      • Sustainability
      • Renewable Energy
      • Green Living
    • Culture
    • Resources
  • Videos
  • Reviews
  • About Us
    • About
    • The Team
    • Advertise
    • Contribute
    • Editorial policy
    • Privacy Policy
    • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.